PSU Volume 67 No 01 JULY 2026

Koempel's Suprahyoid Technique

The Sistrunk procedure, first described in 1920, remains the standard of care for thyroglossal duct remnant (TGDR) excision. It requires removal of the cyst or sinus tract, the central portion of the hyoid bone, and a core of tissue extending superiorly to the foramen cecum. Despite nearly a century of surgical experience, recurrence rates have ranged from as low as 1.2% to as high as 20% across published series, and inadequate dissection of the suprahyoid region has consistently been identified as the primary contributing factor. In response to this persistent clinical challenge, a systematic, anatomically grounded approach to the suprahyoid area was developed through sixteen years of intraoperative observation and formally described in 2014 by Koempel. Koempel's technique, which transformed the most technically uncertain component of the Sistrunk procedure into a reproducible, landmark-guided dissection, achieved a 0% recurrence rate in 74 consecutive cases over nine years and has since been validated in a major systematic review and cited in leading single-institution series worldwide.


Thyroglossal duct remnants, encompassing both cysts and sinus tracts, represent the most common congenital anomaly of the anterior neck in childhood, affecting approximately 7% of the general population. The fundamental difficulty of the procedure lies not in the infrahyoid dissection — which is generally straightforward — but in the segment above the hyoid bone. A thyroglossal tract in the suprahyoid area is rarely visible or palpable during surgery, is often friable and easily disrupted, and may exist as multiple branching ducts rather than a single identifiable structure. Anatomical reconstruction studies using three-dimensional serial sectioning have demonstrated extensive broom-like branching of the thyroglossal duct both above and below the hyoid, with a single tract at the level of the bone itself. Serial pathological analysis of TGDR specimens further established that microscopic thyroglossal duct tissue was present superior to the hyoid in 74% of primary resections and in 100% of revision cases — making complete suprahyoid clearance not merely desirable but essential to surgical cure.


Prior descriptions of the suprahyoid component of the Sistrunk procedure offered little precise guidance. Authors recommended removing a "wide cuff of tissue" or a "generous core of tongue musculature" — language that left the extent of dissection entirely to the surgeon's judgment. Without a reliable anatomical landmark to define the margins of resection, the tissue removed varied substantially from case to case and surgeon to surgeon. Sistrunk himself recognized the difficulty of isolating the tract above the hyoid, cautioning against any attempt to do so, and recommended instead a blind coring technique toward the foramen cecum at a 45-degree angle. While conceptually sound, this guidance proved extremely difficult to reproduce consistently, and two recurrences within a short period prompted a careful re-evaluation of the procedure that ultimately led to the development of the technique described here.


Koempel's modified approach proceeds through twelve discrete steps. Soft tissue skin flaps are raised to 1 cm above the hyoid superiorly and 1 cm below the inferior extent of the TGDR. The median raphe of the strap musculature is divided, and the pretracheal fascia is identified and preserved as the posterior border of dissection throughout. As the surgeon proceeds toward the hyoid, several millimeters of the medial aspect of the strap muscles bilaterally are included in the specimen. Using the laryngeal prominence as a midline reference, 1 to 1.5 cm of the central hyoid is measured, and lateral cuts are made through the bone or cartilage before any tissue superior to the hyoid is addressed — a sequence that eliminates the risk of inadvertently transecting a suprahyoid tract during hyoid division.


The most distinctive and consequential step involves the identification of a specific tissue plane change in the suprahyoid region. Using monopolar electrocautery with a Colorado tip — chosen to minimize bleeding and prevent blood from obscuring the operative field — along with gentle blunt dissection with a small hemostat, the muscle fibers extending superiorly from the resected hyoid segment are carefully and slowly transected. These fibers run in a superior-to-inferior orientation. Dissection continues until the tissue surface transitions from these vertically oriented muscle fibers to a smooth, glistening appearance underneath. This visual and tactile change — representing the interface between the mylohyoid and geniohyoid muscles and a deeper fibrinous layer or a portion of the genioglossus muscle — constitutes the critical anatomical landmark that defines the anterior and lateral margins of suprahyoid resection. It is objective, reproducible, and present regardless of whether a gross duct tract is visible.


Once this plane is reached, a 1 cm diameter area of tongue base is outlined and resected en bloc with the specimen. Careful observation is maintained throughout for the appearance of mucinous material, which would indicate the need for wider excision. The tongue musculature defect is closed with a figure-of-eight suture of absorbable material followed by a second running layer. The hyoid ends are not reapproximated. A rubber band drain is brought out through both ends of the wound. Notably, no attempt is made at any point to isolate or follow a specific duct tract — consistent with the original Sistrunk recommendation — thereby eliminating the risk of tract disruption and incomplete resection that had historically contributed to recurrence.


The clinical impact of adopting this approach was immediate and substantial. In a retrospective series of 94 patients treated over a 16-year period, including both primary and revision cases, 92 underwent a Sistrunk procedure and were eligible for recurrence analysis. Mean patient age was 5.2 years, ranging from 9 months to 16 years. Before consistent application of the suprahyoid technique in 2004, the recurrence rate following a Sistrunk procedure was 11.1% (2 of 18 cases). After systematic adoption of the technique, not a single recurrence was observed in 74 consecutive cases over the following nine years — a difference that was statistically significant by Fisher's exact test (p = 0.037). The overall recurrence rate across the entire Sistrunk cohort was 2.2%, and intraoperative visualization of a suprahyoid tract was documented in only 26.6% of cases, confirming that the technique functions effectively precisely because it does not depend on tract identification.


External validation arrived the following year through the first systematic review specifically addressing surgical management of recurrent thyroglossal duct cysts in children. Nine studies meeting predefined inclusion criteria were identified, comprising 66 patients who underwent 114 secondary surgeries across four main surgical approaches: repeat Sistrunk procedure, en bloc central neck dissection, suture-guided transhyoid pharyngotomy, and the suprahyoid technique described above. Repeat Sistrunk procedures carried a 30.12% recurrence rate. En bloc central neck dissection achieved a 20% recurrence rate. In contrast, both suture-guided transhyoid pharyngotomy and the suprahyoid technique reported 100% success rates in their respective patient cohorts. The review's authors concluded that these were the only two approaches that clearly delineated the specific amount of suprahyoid tissue to be removed, and that this specificity was the likely driver of their superior outcomes. Additional prospective studies and broader institutional adoption were called for to confirm reproducibility.


A 28-year single-surgeon series examining central neck dissection for recurrent and infected thyroglossal duct remnants provided further context. That analysis subdivided the challenges of TGDR surgery into three anatomical compartments — infrahyoid, posterior hyoid, and suprahyoid — and assigned a different surgical strategy to each. Central neck dissection, operating along fascial planes rather than following embryological remnants, reliably controls infrahyoid disease and improves access to the hyoid and posterior hyoid space. However, that same analysis explicitly acknowledged that central neck dissection does nothing to address the difficulties of following the thyroglossal tract into the tongue base — the domain where the suprahyoid technique operates. The two approaches are therefore not competing strategies but complementary ones, with the suprahyoid technique addressing the anatomical frontier that central neck dissection leaves unresolved.


The advantages of the suprahyoid technique are multiple and clinically meaningful. It is applicable to both primary and revision cases, with no difference in the identifiability of the key anatomical landmarks even in previously operated fields — a finding attributed to the fact that in most revision procedures, the hyoid and suprahyoid structures are found largely undisturbed. It requires no specialized equipment, no intraoperative imaging, and no entry into the pharynx. Its defining landmark — the transition from vertically oriented muscle fibers to a smooth, glistening deep plane — provides an objective, reproducible criterion for determining the extent of resection that replaces the subjective estimation inherent in previous descriptions. And its step-by-step structure makes it teachable and applicable by surgeons-in-training and low-volume TGDR surgeons who would otherwise have the highest rates of recurrence.


The technique does not replace the Sistrunk procedure. It refines it at its most vulnerable point, converting the least reproducible component of an otherwise well-defined operation into a systematic, anatomically grounded dissection. The evidence base, while primarily derived from single-institution retrospective series and one systematic review, is internally consistent and directionally unambiguous: where the technique has been applied systematically, recurrence rates fall to zero. Its inclusion in the routine management of both primary and revision thyroglossal duct remnants is supported by the available literature and should be considered by any surgeon seeking to reduce recurrence in this most common of pediatric congenital cervical anomalies.

References:
1- Koempel JA. Thyroglossal duct remnant surgery: a reliable, reproducible approach to the suprahyoid region. Int J Pediatr Otorhinolaryngol. 78(11):1877-1882, 2014
2- Ibrahim FF, Alnoury MK, Varma N, Daniel SJ. Surgical management outcomes of recurrent thyroglossal duct cyst in children--A systematic review. Int J Pediatr Otorhinolaryngol. 79(6):863-867, 2015
3- Isaacson G, Kaplon A, Tint D. Why Central Neck Dissection Works (and Fails) for Recurrent Thyroglossal Duct Remnants. Ann Otol Rhinol Laryngol. 128(11):1041-1047, 2019
4- Jiménez Gómez J, Gaspar Pérez M, Jiménez Arribas P, San Vicente Vela B, Santiago Martínez S, Betancourth Alvarenga J, Güizzo Tobares JR, Sánchez Vázquez B, Esteva Miro C, Álvarez García N, Núñez García B. Treatment of thyroglossal cyst using Koempel's technique: initial experience. Cir Pediatr. 37(1):1-4, 2024

Alternative Management of Giant Omphalocele

Giant omphalocele (GO) remains one of the most formidable challenges in neonatal surgery. Its definition lacks consensus across the literature — most authors require either a defect of 5 cm or more in diameter and/or significant liver herniation within the sac, though some set the threshold at 7 cm or specify that more than 50–75% of the liver must be contained — but regardless of the precise criterion used, GO is not simply a structural anomaly — it is a condition embedded in a web of associated malformations, pulmonary hypoplasia, cardiac defects, and chromosomal aberrations that together dictate its prognosis far more than the defect size alone.


Omphalocele occurs in approximately 1 in 4,000 to 10,000 live births, and its incidence continues to decline in regions where prenatal screening leads to elective termination of pregnancies complicated by severe associated anomalies. Yet for those infants who are born with giant omphalocele, the surgical and neonatal teams face a condition for which no universally accepted treatment protocol exists.


The fundamental problem is biomechanical. The abdominal cavity has never fully developed to accommodate the herniated viscera, and any attempt at immediate primary closure risks catastrophic intra-abdominal hypertension, abdominal compartment syndrome, respiratory failure, and death. This visceroabdominal disproportion has driven clinicians to devise a wide spectrum of approaches, ranging from purely nonoperative strategies that allow epithelialization of the sac over months or years, to minimally invasive staged reduction techniques that aim for definitive fascial closure within the first weeks of life. Understanding how these approaches evolved — and how they compare — is essential for the modern pediatric surgeon.


For decades, the nonoperative "paint-and-wait" strategy served as the default approach for infants whose comorbidities made early surgery prohibitive. This method involves the application of topical escharotic or antimicrobial agents — most commonly silver sulfadiazine, silver-impregnated dressings, or povidone-iodine — to the intact omphalocele membrane, allowing progressive desiccation, eschar formation, granulation tissue development, and ultimately epithelialization of the sac surface. The resulting ventral hernia is then repaired electively, often years later, when the child is larger and physiologically more robust. Advocates of this approach note its low early mortality, avoidance of neonatal anesthesia, and allowance of early enteral feeding. A systematic review by Bauman and colleagues, frequently cited across the literature, concluded that nonoperative delayed closure was associated with lower mortality and faster achievement of full enteral feeding compared to early staged surgical approaches. However, the morbidity and social costs of leaving a child with an unrepaired giant abdominal wall defect for years, the risk of infection, and the need for eventual complex surgical reconstruction are real and significant limitations.


The question of which topical agent to use within the paint-and-wait paradigm has itself generated debate. Dörterler, reporting on 22 infants treated in Turkey, described a protocol combining daily povidone-iodine application with a powdered antibiotic spray (polymyxin B, bacitracin, and neomycin) and circumferential elastic bandaging using a cohesive elastic wrap. In this series, conservative management lasted a mean of 11 days before early graft closure was performed, with a mean total hospital stay of only 35 days among survivors. Seven patients died in the first week, all with larger defects and higher rates of complications — a sobering reminder that even with optimized topical care, the most severe cases carry a mortality approaching 30%. The elastic bandaging component of this protocol deserves attention. By providing gentle circumferential compression from xiphoid to pubis, it facilitates gradual reduction of sac contents while supporting repositioning of the liver toward the midline, effectively functioning as a noninvasive silo. This principle — gradual, controlled external compression to recruit abdominal domain — is the conceptual thread that runs through virtually all the alternative strategies reviewed here.


Kogut and Fiore formalized this concept with their serial taping technique, reported from a Las Vegas tertiary children's hospital. In their series of 10 infants treated between 2010 and 2017, the omphalocele sac was serially taped at the bedside in the NICU using Mastisol adhesive and strips of clear Tegaderm applied in a criss-cross fashion across the defect. No infant underwent an attempt at primary closure first. Tape was applied daily in successive layers, maintaining forward tension on the lateral abdominal wall muscles while gently reducing the volume of the amniotic sac. Crucially, this was done on the awake infant — a built-in safety mechanism, since an awake baby cannot be taped too tightly without protest. The mean time to operative closure was 13.7 days. Six of the ten infants achieved primary fascial closure without any mesh; four required a small Gore-Tex patch, most of which were subsequently removed and replaced with primary repair. This approach is compelling in its simplicity. It requires no special materials beyond adhesive tape and skin preparation, avoids operative anesthesia during the reduction phase, preserves the fascial edges and amnion intact, and keeps the option of topical escharotic therapy available if the method fails. Complications were minimal, and sac integrity was maintained in all cases until operative closure.


The most technically sophisticated evolution of the staged reduction concept is the nonsurgical silo technique described by Abello and colleagues, developed over 25 years at institutions in Colombia and Chile. Their technique employs DuoDERM hydrocolloid dressing cut in a "T" shape, fixed bilaterally to the skin lateral to the defect and wrapped around the omphalocele sac to construct a 360-degree silo without a single suture. Tongue depressors placed at the apex of the silo serve as gentle clamps that are progressively tightened every one to two days under continuous monitoring of intra-abdominal pressure, with a strict ceiling of 20 cm H2O. The protocol unfolds in three phases: silo reduction until the liver and bowel are fully reintegrated (Phase 1), amnion inversion with skin edge approximation to simulate definitive closure and assess tolerance (Phase 2), and definitive surgical closure in the operating room (Phase 3). In a multicenter retrospective cohort of 40 patients spanning 1994 to 2019, anatomical closure was achieved in 95% of cases, median time to closure was 12 days, and there were no deaths attributable to the technique itself. The four deaths observed were all related to severe associated cardiac or pulmonary conditions — precisely the comorbidities that drive mortality in GO regardless of surgical approach.


A parallel retrospective cohort study by Barrios-Sanjuanelo and colleagues specifically analyzed mortality predictors among 30 neonates treated with the Abello technique in Barranquilla, confirming an overall mortality rate of 16.7% — well within the 13–25% range typically cited for giant omphalocele — with mortality significantly associated with the presence of other malformations, congenital heart defects, pentalogy of Cantrell, and pulmonary hypertension. Critically, no mortality was associated with technique-related complications, silo reduction time, or abdominal closure timing. This finding reinforces a principle that is now widely accepted but not always acted upon. In giant omphalocele, survival is determined far more by associated anomalies than by the choice of surgical technique. This has important implications for counseling families and for designing future comparative studies.


For the subset of patients in whom neonatal closure is not achievable and "paint-and-wait" becomes the de facto management, the challenge eventually becomes one of delayed fascial reconstruction, often years later. Boglione and colleagues from Buenos Aires reported their experience using the San Martín technique — an anatomo-physiological procedure originally described for large midline incisional hernias in adults — for the delayed closure of giant omphaloceles in eight children at a median age of six years. The technique involves bilateral curvilinear release incisions on the outer aspect of the anterior rectus sheath, mobilizing aponeurotic flaps medially and suturing them together at the midline over the posterior sheath, followed by approximation of the rectus muscles and any remaining anterior sheath. No prosthetic mesh was required in any of the eight patients. Median postoperative mechanical ventilation was three days, enteral feeding resumed at a median of four days, and hospital stay was ten days — strikingly efficient outcomes for what represents some of the most complex abdominal wall reconstruction in pediatric surgery. There were no complications attributable to the technique itself during follow-up ranging from 18 months to eight years.


Finally, at the frontier of adjunctive therapies, Armijo and colleagues described the combined use of preoperative botulinum toxin A injections and subfascial tissue expanders in a four-year-old boy with giant omphalocele and multiple comorbidities including chronic lung disease, tracheostomy, and pulmonary hypertension. Botulinum toxin A, injected under ultrasound guidance into the transversus abdominis, internal oblique, and external oblique muscles bilaterally, induces a reversible flaccid paralysis of the lateral abdominal wall musculature that peaks at four to six weeks and subsides over three months. This chemically induced muscle relaxation reduces fascial tension at closure, decreases intraabdominal pressure, and may even attenuate postoperative pain by inhibiting the release of substance P and glutamate. When combined with the domain-expanding effect of the tissue expanders, definitive midline fascial closure was achieved with the patient remaining complication-free at nine months postoperatively.


Taken together, these six bodies of work map a continuum of therapeutic strategies for giant omphalocele that is far richer — and far more nuanced — than the binary "operate early versus paint-and-wait" framing that has historically dominated the literature. The choice among serial taping, elastic bandaging with topical agents, nonsurgical silo reduction, delayed fascial reconstruction with anatomical techniques, or botulinum toxin augmentation is not simply a matter of surgeon preference; it must be individualized to the infant's physiology, the severity of associated anomalies, the institutional resources available, and a candid assessment of what the family can sustain over what may be a months- or years-long treatment course. What the evidence increasingly supports is that gradual, monitored, external pressure — however it is applied — is the key mechanism driving successful domain recruitment, and that the infant's associated comorbidities, not the defect itself, are the true arbiters of survival.

References:
1- Kogut KA, Fiore NF. Nonoperative management of giant omphalocele leading to early fascial closure. J Pediatr Surg. 53(12):2404-2408, 2018
2- Barrios-Sanjuanelo A, Abelló-Munarriz C, Cardona-Arias JA. Mortality in neonates with giant omphalocele subjected to a surgical technique in Barranquilla, Colombia from 1994 to 2019. Sci Rep. 11(1):310, 2021
3- Abello C, A Harding C, P Rios A, Guelfand M. Management of giant omphalocele with a simple and efficient nonsurgical silo. J Pediatr Surg. 56(5):1068-1075, 2021
4- Boglione M, Aleman S, Reusmann A, Rubio M, Marcelo B. Giant omphalocele: Delayed closure using the San Martin technique following epithelialization of the membrane. J Pediatr Surg. 56(6):1247-1251, 2021
5- Armijo AJ, Calvano J, Thomason NT, Arndt C, Shetty AK, Byrd D, Falcon R, Petersen TR, Soneru C. Successful Administration of Preoperative Botox for Giant Omphalocele Repair With Ultrasound Guidance. Cureus. 15(4):e37850, 2023
6- Rombaldi MC, Barreto CG, Feldens L, Holanda F, Takamatu EE, Schopf L, Peterson CAH, Costa EC, Cavazzola LT, Isolan P, Fraga JC. Giant omphalocele: A novel approach for primary repair in the neonatal period using botulinum toxin. Rev Col Bras Cir. 50:e20233582, 2023

Peritoneal Loose Body

Peritoneal loose bodies (PLBs) represent one of the more curious and frequently overlooked entities in abdominal medicine. These free-floating intraperitoneal masses are benign in nature, yet their rarity and nonspecific clinical presentation make them a persistent diagnostic challenge for surgeons, radiologists, and clinicians alike. Most physicians will encounter one only by accident — during an imaging study ordered for an unrelated complaint, during an exploratory laparoscopy, or at autopsy. This incidental quality defines much of what makes PLBs so medically interesting. They exist quietly inside the abdomen, often causing no trouble at all, yet they occasionally grow large enough to compress surrounding structures and provoke symptoms that mimic far more serious disease.


The most widely accepted explanation for how PLBs form begins with the epiploic appendages — small, fat-filled pouches that hang from the outer surface of the colon along its antimesenteric border. When one of these appendages undergoes torsion, its blood supply is interrupted. Ischemia follows, leading to infarction and aseptic fat necrosis. The necrotic tissue then undergoes saponification, a chemical transformation of fat, followed by progressive calcification and fibrosis. As the connecting pedicle atrophies, the calcified mass detaches completely from the colon wall and becomes a free body within the peritoneal cavity. This sequence — torsion, ischemia, necrosis, saponification, calcification, detachment — was first conceptualized in the nineteenth century and remains the dominant theory today, though it is not the only one.


Alternative origins have been proposed. Autoamputated adnexal tissue, subserosal uterine leiomyomas that detach and undergo calcification, pancreatic fat, and even the products of a medically managed ectopic pregnancy have all been identified as sources of PLBs in isolated reports. The common thread is a process of detachment, necrosis, and subsequent encapsulation by fibrous tissue, after which the mass becomes independent of any vascular supply. This absence of blood supply is, in fact, one of the defining characteristics of a true PLB — along with its high mobility within the peritoneal cavity and the absence of tumor markers when evaluated.


Once free within the peritoneum, these bodies do not remain static. They are thought to slowly accumulate protein-rich exudate from peritoneal fluid on their surface, growing in a manner that has been compared to the formation of a pearl — layer upon layer deposited over an initiating core. The increased temperature of the peritoneal environment contributes to the characteristic appearance of the cut surface, which resembles a hard-boiled egg: a white, firm outer shell of lamellar fibrous tissue surrounding a central yellowish zone of calcified necrotic fat. This "boiled egg" appearance is now considered a hallmark of PLBs both grossly and radiologically.


The typical PLB is small, ranging from roughly half a centimeter to two and a half centimeters in its largest dimension. At this size, it is virtually always asymptomatic and is rarely detected during life. However, PLBs can grow substantially larger. When a PLB exceeds five centimeters in diameter, it is classified as a giant PLB; those exceeding ten centimeters have been designated super-giant. The distinction matters clinically because size correlates with the likelihood of causing symptoms. The largest PLBs documented in the literature have approached twenty centimeters, though such extremes are extraordinarily rare. Cases of multiple simultaneous PLBs found in the same patient have also been reported.


Demographically, PLBs show a strong predilection for men, with a male-to-female ratio reported in the range of 17:3 to 18:4 across accumulated case series. They occur predominantly in middle-aged and older individuals, most commonly between the fifth and seventh decades of life, though cases in younger patients and even in children have been described. The pelvic cavity is the most frequent site of discovery, a consequence of gravity drawing the freely mobile mass to the most dependent part of the abdomen.


The vast majority of PLBs produce no symptoms whatsoever. They are identified incidentally during imaging performed for other reasons, or are found unexpectedly during abdominal surgery or autopsy. When symptoms do occur, they are typically nonspecific: dull lower abdominal discomfort, a vague sense of fullness, or intermittent constipation. Giant PLBs, by virtue of their size and mobility, can cause more pronounced problems. Compression of the rectosigmoid colon may produce constipation or even frank bowel obstruction. Pressure on the bladder or urethra can result in urinary retention or urinary tract infections. Neurological symptoms involving the lower extremities have been described when a large pelvic mass compresses adjacent nerve structures.


Beyond these compressive complications, PLBs can serve as an unexpected hazard during invasive procedures. A large intraperitoneal mass with a hard, smooth surface can act as a fulcrum beneath loops of bowel during percutaneous procedures such as peritoneal dialysis catheter placement, potentially predisposing the bowel to perforation. This underscores the importance of recognizing PLBs on preoperative imaging before undertaking any percutaneous abdominal intervention.

Preoperative diagnosis of a PLB is notoriously difficult, and in the majority of reported cases, the correct diagnosis was not suspected before surgery. The condition is simply too uncommon for most clinicians to include it readily in their differential, and its imaging features, while distinctive in retrospect, overlap considerably with other entities. The differential diagnosis is broad and includes both benign and malignant conditions: teratoma, calcified uterine leiomyoma, mesenteric tumor, ovarian cancer, colorectal cancer, peritoneal metastases, calcified lymph nodes, urinary or biliary calculi, tuberculous granulomas, appendicoliths, and retained foreign bodies.


Computed tomography is the most useful imaging modality. A PLB characteristically appears as a well-defined, oval or round mass with central calcification and a distinct surrounding soft tissue component, with a clear fat plane separating it from adjacent organs. Because PLBs are freely mobile, rescanning the patient in a different position — prone instead of supine, for example — can demonstrate a change in the location of the mass, which is highly suggestive of this diagnosis. On magnetic resonance imaging, PLBs show low signal intensity on both T1 and T2 sequences, similar to that of muscle or dense collagen, and crucially, they show no contrast enhancement — a feature that helps distinguish them from leiomyomas and teratomas, both of which typically enhance. Ultrasound may reveal a hypoechoic round mass that shifts with probe compression. Plain radiography, when calcification is present and the mass is large, may show a mobile calcified density within the abdomen.


Despite these imaging clues, definitive diagnosis almost always requires surgical exploration and histopathological confirmation. Under direct vision, PLBs have a distinctive appearance: smooth, white to pale yellow, ovoid, hard, and glistening, resembling a boiled egg. Microscopy reveals the characteristic architecture of laminated, acellular fibrous tissue surrounding a core of calcified necrotic fat, often with numerous microcalcifications throughout the fibrous layers.


The management of PLBs is guided primarily by symptoms and the certainty of diagnosis. In asymptomatic patients where the imaging appearance is sufficiently characteristic to allow a confident diagnosis, conservative observation with serial imaging is a reasonable approach. No recurrences have been reported following excision, and no malignant transformation has been documented in the literature. Surgical removal is indicated when the PLB is symptomatic, when it is large enough to risk causing complications, or when the diagnosis remains uncertain and malignancy cannot be excluded. Laparoscopy is now the preferred approach when the diagnosis is considered preoperatively, as it offers all the advantages of minimally invasive surgery and is entirely adequate for extracting even large PLBs. Open laparotomy has historically been more common simply because the diagnosis was rarely made before the abdomen was opened. Any PLB removed surgically should be sent for pathological examination to confirm the diagnosis and exclude other pathology.


Peritoneal loose bodies occupy a peculiar niche in clinical medicine — benign, slow-growing, overwhelmingly asymptomatic, and almost always stumbled upon rather than sought. Their rarity ensures that most clinicians will never encounter one deliberately. Yet awareness of this entity has real practical consequences: it can prevent unnecessary anxiety over a benign finding, avoid misdiagnosis as a malignant pelvic mass, prevent procedural complications during abdominal interventions, and guide appropriate management. As imaging technology continues to improve and abdominal CT and MRI become ever more routine, PLBs are likely to be detected with increasing frequency. Recognizing the boiled egg in the peritoneal cavity for what it is remains both an intellectual exercise and a genuine clinical imperative.

References:
1- Oom R, Cunha C, Guedes VM, Féria LP, Maio R. Corpo Peritoneal Livre Gigante: Caso Clínico e Revisão da Literatura [Giant Peritoneal Loose Body: Case Report and Review of Literature]. Acta Med Port. 31(5):272-276, 2018
2- Guo S, Yuan H, Xu Y, Chen P, Zong L. Giant peritoneal loose body: A case report. Biomed Rep. 10(6):351-353, 2019
3- Baert L, De Coninck S, Baertsoen C, Lissens P, Djoa L. Giant peritoneal loose body: a case report and review of the literature. Acta Gastroenterol Belg. 82(3):441-443, 2019
4- Arwikar AS, Chavarkar S, Sudhamani S, Mukharji S. Peritoneal loose body with boiled egg appearance. Indian J Pathol Microbiol. 65(2):511-512, 2022
5- Yang N, Zhang S, Fang M, Wang K, Lin H, Li L. Peritoneal loose body: a possible cause of bowel perforation during PD catheter insertion. Ren Fail. 44(1):858-859, 2022
6- Fu W, Chen X, Liu Q, Yao S. A nearly-missed peritoneal loose body. Front Oncol. 16:1746145, 2026

PSU Volume 67 No 02 AUGUST 2026

Kaposiform Hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor that primarily affects infants and young children, though it can occasionally present in adults. First distinguished as a separate entity in 1993, KHE occupies an intermediate position in the spectrum of vascular neoplasms — neither fully benign nor overtly malignant — and is characterized by its capacity for locally invasive and infiltrative growth. Its estimated annual incidence is approximately 0.071 per 100,000 children, though the true prevalence is likely higher, as small or atypical lesions may be misclassified as other vascular anomalies. A slight male predominance has been noted in larger case series.


The underlying cause of KHE remains incompletely understood. Most cases arise sporadically without an identifiable trigger, though rare reports describe worsening after trauma, surgery, infection, or vaccination, suggesting that inflammatory stimuli may aggravate the disease. At the molecular level, somatic mutations — including activating variants in the GNA14 gene — have been identified in a subset of specimens, implicating the MAPK/ERK signaling pathway. Whether these mutations are causative or secondary is still debated. Dysregulation of both angiogenesis and lymphangiogenesis are central to KHE's pathology. Elevated vascular endothelial growth factor-C and its receptor (VEGFR-3), along with high angiopoietin-2 levels, have been implicated in driving abnormal vessel formation and contributing to the consumptive coagulopathy that defines the disease's most dangerous complication.


On histopathology, KHE is recognized by infiltrating, rounded, confluent nodules composed of spindle-shaped endothelial cells that form malformed lymphatic channels and slit-like vascular lumina. Microthrombi, hemosiderin deposits, and eosinophilic hyaline bodies are frequently observed. Immunohistochemical staining shows positivity for vascular markers CD31 and CD34, and lymphatic markers D2-40, VEGFR-3, and Prox-1, while staining is negative for GLUT-1 — a feature that distinguishes KHE from infantile hemangioma — and for HHV-8.


KHE exhibits considerable clinical heterogeneity. Lesions are classified by depth of involvement into three morphological types: superficial (confined to skin and subcutaneous tissue), mixed (involving both superficial and deep structures including muscle, bone, or joint), and deep (no cutaneous involvement, affecting internal organs, retroperitoneum, mediastinum, or bone). A further clinically important subgroup is intracavitary KHE — tumors arising primarily within body cavities such as the thoracic or abdominal cavity, retroperitoneum, or pelvic space, where the bulk of the lesion is contained within the cavity and may involve serosal surfaces, mesentery, or cavity-specific structures. The mixed type is the most common overall, while deep and intracavitary lesions account for a smaller proportion of cases but carry the greatest diagnostic challenge and the most severe clinical burden.


Cutaneous KHE typically presents as erythematous, violaceous, or darkened patches, plaques, or firm nodules. When associated with the Kasabach-Merritt phenomenon (KMP), lesions become tense, engorged, purpuric, hot to the touch, and painful. Deep lesions without skin involvement may present with nonspecific symptoms such as abdominal distension, jaundice, respiratory distress, or unexplained thrombocytopenia and coagulopathy, often resulting in significant diagnostic delay. Intracavitary lesions in particular may compress adjacent organs or critical structures as they enlarge, leading to pleural effusion, pericardial effusion, peritoneal effusion, obstructive jaundice, gastrointestinal bleeding, or airway compromise. Approximately 90% of cases become evident within the first year of life, and about half of cutaneous lesions are detectable at birth. Unlike infantile hemangioma, KHE does not undergo spontaneous involution and tends to progress without treatment.


The most feared complication of KHE is the Kasabach-Merritt phenomenon, which occurs in 42–71% of patients. KMP is defined by profound thrombocytopenia — with median platelet counts around 21 × 10?/L at presentation — combined with consumptive coagulopathy and hypofibrinogenemia. It is critical to understand that KMP does not occur with infantile hemangioma; it is exclusively associated with KHE and the related tufted angioma. KMP carries a mortality rate estimated between 10–30%, and deaths are most commonly attributable to hemorrhage in vital organs. Intracavitary KHE carries a disproportionately high KMP burden — studies have documented KMP rates approaching 80% in this subgroup, compared to roughly 30% in non-intracavitary cases — a disparity that may reflect the anatomical microenvironment of body cavities, which lack the soft tissue buffering present in superficial or extremity lesions, facilitating early compression of vascular structures, local blood stasis, and amplification of platelet trapping. The rich chylous pools and subserosal lymphatic networks within the thoracic and abdominal cavities may further intensify the local accumulation of coagulant substances and increase susceptibility to KMP.


Risk factors for KMP include young age at presentation, large tumor size (particularly greater than 8 cm), and anatomic location — intrathoracic and retroperitoneal lesions are disproportionately associated with KMP. Patients with KMP tend to have larger tumors and present at a younger age than those without.


Beyond KMP, KHE causes significant morbidity through musculoskeletal involvement. The tumor's infiltrative and destructive growth can erode bone, invade joints, and alter the mechanical properties of surrounding connective tissue, leading to decreased range of motion, chronic pain, joint contractures, and progressive scoliosis — particularly with thoracic or retroperitoneal lesions. Tumor stimulation, inflammatory cell infiltration, and fibrin deposition near vertebral structures can promote local fibrosis, and during skeletal development, contractures may mechanically pull on bone, eventually driving progressive thoracic deformity. These musculoskeletal complications are more common in older children and can persist even after hematologic parameters normalize. Lymphedema is a recognized long-term sequela, especially with lesions involving the proximal extremities near lymph node basins. Intracavitary KHE is additionally associated with a higher burden of organ dysfunction — including jaundice and abnormal liver function from bile duct or portal vein compression, gastrointestinal hemorrhage from intestinal wall infiltration, and structural deformities such as scoliosis from paraspinal involvement — complications that are far less common in non-intracavitary disease and that can in severe cases impair respiratory and circulatory function and contribute to death.


Diagnosis of KHE requires integration of clinical, laboratory, imaging, and pathological data. Ultrasound is useful for superficial or small lesions, typically revealing heterogeneous, ill-defined, hypervascular masses. However, MRI is the preferred modality and provides the most comprehensive assessment of disease extent. On MRI, KHE characteristically demonstrates iso-intensity relative to adjacent muscle on T1-weighted imaging and heterogeneous hyperintensity on T2-weighted imaging, with intense, heterogeneous gadolinium enhancement. Lesions commonly show ill-defined margins, multiplanar involvement, adjacent fat stranding, and bone or joint changes including cortical destruction or remodeling. CT can complement MRI in evaluating bony involvement and is more practical in critically ill patients. Three morphological patterns have been described: well-defined solid mass, solid central mass with surrounding infiltrative regions, and purely infiltrative lesion without a distinct solid core. Biopsy remains the gold standard for diagnosis and should be obtained when clinically safe. In patients with classic KMP and a compatible vascular mass on imaging, histologic confirmation may not always be required before initiating treatment.


No FDA-approved therapy exists specifically for KHE. Management must be individualized based on disease severity, the presence or absence of KMP, lesion location, and patient age. For patients with KMP, aggressive combination therapy is required — monotherapy is generally insufficient. The mTOR inhibitor sirolimus, combined with short-term corticosteroids, has emerged as the preferred first-line regimen for KHE with KMP. Sirolimus works by inhibiting the PI3K/AKT/mTOR pathway, which mediates downstream effects of both VEGF-C/VEGFR3 and angiopoietin-2/Tie-2 signaling, and may additionally suppress the proliferation of KHE endothelial cells through effects on autophagy-related pathways. Response rates with sirolimus are high, and angiopoietin-2 levels have been shown to fall significantly with treatment.


For patients without KMP, sirolimus monotherapy is effective, and randomized trial evidence demonstrates that low-dose sirolimus (targeting trough concentrations of 5–8 ng/mL) is non-inferior to high-dose sirolimus (10–15 ng/mL) at one year of treatment, with fewer respiratory, skin, and mucosal adverse events. Low-dose sirolimus therefore represents a safer long-term option for non-KMP patients requiring prolonged therapy, though high-dose regimens retain a role for severe cases and those complicated by KMP. Intracavitary KHE, even when treated with sirolimus-based regimens, tends to show lower sustained response rates at 6 and 12 months compared to non-intracavitary disease, underscoring the need for vigilant systemic monitoring and active complication management alongside tumor-directed treatment; outcomes at 24 months, however, appear more comparable between the two groups.


Vincristine — alone or combined with corticosteroids or antiplatelet agents such as ticlopidine — remains an alternative first-line option for KMP, with an overall response rate of approximately 72%. Corticosteroids alone yield lower sustained response rates and carry significant long-term side effects. Propranolol and interferon-alpha have been used with variable and generally less reliable results; interferon-alpha in particular carries a risk of serious neurologic complications and is contraindicated in children under one year of age. Topical sirolimus and tacrolimus ointments have shown efficacy for superficial lesions, offering a way to avoid systemic drug exposure in selected patients.


Surgical resection is reserved for cases where complete and safe excision is achievable, as the infiltrative nature of most KHE makes curative surgery impractical for the majority. Elective resection during active KMP is generally discouraged due to the risk of worsening coagulopathy and hemorrhage. Arterial embolization can serve as an adjunct in cases with extensive, unresectable lesions or refractory KMP, providing rapid reduction in tumor blood flow. Platelet transfusions should be avoided unless the patient is actively bleeding or being prepared for an invasive procedure.

KHE significantly impairs health-related quality of life in affected children and their families. Both physical functioning — particularly in children with activity-limiting musculoskeletal complications — and psychosocial functioning are measurably reduced compared to healthy peers. KMP and activity dysfunction are the strongest risk factors for poor quality of life. Parents of children with KHE consistently report high levels of worry, emotional burden, and disruption to daily activities regardless of lesion location or parental education level.


Complete tumor resolution is uncommon. Residual lesions after treatment often persist as vascular staining, telangiectasia, soft tissue fibrosis, or subcutaneous infiltrates. Long-term surveillance is warranted, as untreated residual KHE can continue to infiltrate surrounding tissue and cause progressive fibrosis and joint destruction over time. Early and accurate diagnosis, multidisciplinary management, and individualized treatment remain the cornerstones of improving outcomes in this challenging disease.

References:
1- Ryu YJ, Choi YH, Cheon JE, Kim WS, Kim IO, Park JE, Kim YJ. Imaging findings of Kaposiform Hemangioendothelioma in children. Eur J Radiol. 86:198-205, 2017
2- Schmid I, Klenk AK, Sparber-Sauer M, Koscielniak E, Maxwell R, Häberle B. Kaposiform hemangioendothelioma in children: a benign vascular tumor with multiple treatment options. World J Pediatr. 14(4):322-329, 2018
3- Ji Y, Chen S, Li L, Yang K, Xia C, Li L, Yang G, Kong F, Lu G, Liu X. Kaposiform hemangioendothelioma without cutaneous involvement. J Cancer Res Clin Oncol. 144(12):2475-2484, 2018
4- Dai S, Yang K, Qiu T, Zhou J, Zhang X, Chen S, Li L, Ji Y. Health-Related Quality of Life in Children With Kaposiform Hemangioendothelioma. Front Pediatr. 10:720611, 2022
5- Huo J, Chen S, Li J, Liu C. Retroperitoneal kaposiform hemangioendothelioma with kasabach-merritt phenomenon in children: A case report and review of the literature. Front Pediatr. 11:1138689, 2023
6- Zhou J, Lan Y, Qiu T, Zhang Z, Gong X, Zhang X, Yang C, Zhou Z, Zhang Y, Yang M, Fu J, He C, Peng Q, Hu F, Xia C, Kong F, Chen S, Ji Y. Efficacy and safety of high-vs low-dose sirolimus in patients with kaposiform hemangioendothelioma: A randomized clinical trial. J Am Acad Dermatol. 93(1):124-131, 2025
7- Zhou J, Ji Y. Kaposiform hemangioendothelioma. J Am Acad Dermatol. 12:S0190-9622(26)00396-8, 2026

Accessory Breast Tissue

Accessory breast tissue, also termed ectopic or supernumerary breast tissue, refers to mammary tissue located anywhere on the body outside its normal position on the anterior thoracic wall. It is a congenital anomaly that originates during embryonic development. Around the sixth week of gestation, paired mammary ridges, commonly called the "milk lines," appear bilaterally on the ventral surface of the embryo and extend from the axilla to the inguinal and vulvar region. Under normal circumstances these ridges regress almost entirely, leaving only a single pair of buds in the pectoral region that go on to form the adult breasts. When regression fails or is incomplete at any point along this line, residual mammary elements persist and may later develop into accessory breast tissue. Because this represents the reappearance of a structure typical of more primitive mammals, in which multiple paired glands run the length of the trunk, the condition is regarded as atavistic, a reversion to an ancestral pattern. Although the milk line is the usual site, ectopic mammary elements have occasionally been described well beyond it, including the neck, back, face, thigh, and even the sole of the foot.


The spectrum of accessory mammary tissue is conventionally described by a classification scheme dating from 1915 that divides it into eight categories according to which components, glandular tissue, nipple, and areola, are present. The most complete form contains all three elements and constitutes a fully formed supernumerary breast. Subsequent categories describe progressively incomplete combinations: glandular tissue with a nipple but no areola; glandular tissue with an areola but no nipple; glandular tissue alone, sometimes called mamma aberrata; a nipple and areola without underlying glandular tissue, known as pseudomamma; a nipple only, which is the classic supernumerary nipple or polythelia; an areola only, termed polythelia areolaris; and finally a patch of hair only, polythelia pilosa. In everyday practice two broad terms dominate: polythelia, denoting supernumerary nipples generally without associated breast tissue, and polymastia, denoting accessory glandular tissue with or without a nipple. The distinction is clinically meaningful because the presence or absence of true glandular tissue determines whether the lesion can undergo the same physiological and pathological changes as a normal breast.


Reported prevalence varies considerably depending on the population studied and the definitions used, ranging broadly from about 0.22% to 6% of the general population. Polythelia tends to fall within the lower portion of that range, while accessory glandular tissue is reported in roughly 0.4% to 6% of women and 1% to 3% of men. Geographic and ethnic differences exist, with higher frequencies described among Asian and Japanese women and lower frequencies among those of Caucasian background. Supernumerary nipples have historically been described as somewhat more common in males, yet among patients who actually present for clinical evaluation or excision, the great majority are female and often young, likely because women more frequently seek correction for cosmetic or symptomatic reasons. Lesions are usually solitary and unilateral, though bilateral and multiple lesions occur; when unilateral, a slight predilection for the right side has traditionally been noted, although this is not invariable.


By anatomical site, the axilla is by far the most common location for ectopic breast tissue, followed by other regions of the chest, the inframammary fold, and the abdomen. The condition is most often sporadic, but familial clustering is well recognized, including instances of male-to-male transmission. The proposed inheritance patterns are heterogeneous, encompassing autosomal dominant transmission with incomplete penetrance, X-linked dominant, and autosomal recessive modes, and somatic mutations arising early in embryonic life may also contribute. Accessory mammary tissue has been linked to congenital anomalies, most consistently of the renal and urinary tract, and less frequently to cardiovascular malformations, kidney tumors, and chromosomal conditions such as trisomy 21. These associations, however, are inconsistent, and large cohorts composed mainly of adults frequently identify no accompanying congenital anomaly at all. Because most congenital anomalies are detected in early childhood, the apparent rarity of associations in adult series may partly reflect the age at which patients present. Ultrasonographic screening of the kidneys and abdomen is sometimes recommended as part of diagnostic follow-up, particularly in younger patients.


Clinically, accessory breast tissue is frequently asymptomatic and may be noticed only as a cosmetic concern or a cutaneous protuberance, often slightly more pigmented than surrounding skin. When functional glandular tissue is present, it responds to the same hormonal stimuli as orthotopic breast tissue, so the lesion may enlarge and become symptomatic at puberty, during pregnancy, or while breastfeeding. Forms consisting of glandular tissue alone, lacking an external nipple or areola, are especially prone to going unrecognized until hormonal stimulation makes them apparent. The characteristic complaint is a soft axillary mass, commonly a few centimeters in size, accompanied by cyclic pain coinciding with menstruation, swelling, tenderness, and fluctuation in volume. Larger lesions may restrict shoulder movement or cause irritation against clothing, and the cosmetic appearance often provokes anxiety. In children and adolescents the diagnosis is uncommon and may be delayed, yet it can occur even before menarche, and a tender, periodically enlarging axillary mass in this age group should raise suspicion.


The differential diagnosis is broad and accounts for frequent misidentification. Accessory breast tissue has been mistaken for lipoma, lymphadenopathy, hidradenitis suppurativa, sebaceous cyst, vascular malformation, neurofibroma, lymphoma, and metastatic disease, among others. Ultrasonography is the preferred first-line imaging modality, demonstrating hypoechoic, septate, glandular-appearing tissue analogous to normal breast, sometimes with duct ectasia. Bilateral imaging is advisable to detect contralateral involvement, which may be asynchronous. Mammography and magnetic resonance imaging serve as useful adjuncts when the diagnosis is uncertain or when malignancy or another neoplastic process must be excluded, and fine-needle aspiration or core-needle biopsy can provide definitive confirmation. Histologically, the tissue shows the architecture of normal breast, with mammary lobules and lactiferous ducts in the dermis, surrounding connective tissue stroma, and bundles of nipple-type smooth muscle, often in proximity to cutaneous adnexal glands.


Because it is genuine mammary tissue, the ectopic gland is susceptible to the full range of benign and malignant breast disease. Reported benign processes include fibroadenoma, fibrocystic change, ductal hyperplasia, duct ectasia, lactating adenoma, and intraductal or intracystic papilloma, the last being distinctly uncommon in this setting. Malignant transformation, while rare, is documented and includes ductal carcinoma in situ and invasive carcinoma. Importantly, tumors arise within glandular tissue rather than from a supernumerary nipple in isolation; when malignancy or significant proliferative disease is found in association with a supernumerary nipple, it typically reflects underlying accessory glandular tissue. This underscores the principle that wherever ectopic mammary tissue is identified, the possibility of accompanying breast pathology should be considered.


Management is largely conservative. Surgical excision is reserved for symptomatic lesions, persistent cosmetic concern, diagnostic uncertainty, or suspicion of neoplasm, and prophylactic removal is not currently recommended. Excision through a small incision placed within a natural axillary fold is generally safe and effective, with liposuction reserved for larger lesions; reported complications include hematoma, seroma, infection, residual tissue, contour irregularity, and hypertrophic scarring. Operating before pregnancy is often favored because reoperation rates are lower and patient satisfaction higher. Overall, accessory breast tissue is a benign, usually innocuous condition whose chief clinical importance lies in correct recognition, distinction from other masses, and awareness of its capacity to develop the same diseases as a normally situated breast.

References:
1- De la Torre M, Lorca-García C, de Tomás E, Berenguer B. Axillary ectopic breast tissue in the adolescent. Pediatr Surg Int. 38(10):1445-1451, 2022
2- El Malih S, Ezzahi M, Haloua M, Tahiri L, Akammar A, El Bouardi N, Alami B, Alaoui Lamrani MY, Maaroufi M, Boubbou M. Unusual intracystic papilloma arising from ectopic axillary breast tissue: Case report. Radiol Case Rep. 18(10):3414-3420, 2023
3- Class MM, McCoy K, Melin AA, Hafeez F, Abidi N, Krakowski AC. Bilateral accessory axillary breast tissue in a premenarchal female. Pediatr Dermatol. 41(4):704-706, 2024
4- Al Assaad M, Vulcain DR, Phan A, Boyraz B, Hoda SA. Polythelia (Supernumerary Nipple): Clinicopathological Characterization of an Atavistic Lesion. Int J Surg Pathol. 2025 33(8):1735-1741, 2025
5- Sag S, Sonmez Y, Gungormez EK, Canbaz FA, Gercel G, Yavuzer D, Yasar E, Thomas DT. Pediatric Breast Pathologies: 5-Year Experience and Proposal for a Risk-Based Management Algorithm. J Pediatr Adolesc Gynecol. S1083-3188(26)00309-8, 2026

Endoscopic Functional Luminal Imaging Probe

For most of the history of gastroenterology, the esophagus has been judged by what the eye could see and what a swallow could tell. An endoscope reveals the mucosa; a barium column traces the path of liquid downward; a manometry catheter records the pressures that ripple along the muscular tube as a patient swallows on cue. Each of these tools answers a real question, yet each leaves a gap. None of them measures directly how the esophagus behaves as a mechanical object—how readily its walls yield to stretch, how wide its narrowest point will open under load, how the muscle answers when the lumen is filled rather than when a bolus is swallowed. The functional luminal imaging probe, almost always abbreviated to FLIP, was built to close that gap, and over the past decade it has moved from a research curiosity into a working clinical instrument, including, more recently, in children.


The principle behind FLIP is elegant in its simplicity. A catheter carrying a cylindrical balloon is passed transorally and positioned across a region of interest, most often the esophagogastric junction. Inside the balloon sit sixteen impedance-planimetry sensors that measure the electrical voltage between neighboring electrodes as the balloon is filled with a conductive fluid. From those readings the system reconstructs cross-sectional area at multiple points along the balloon and pairing that geometry with a built-in pressure sensor yields the central number of the field: the distensibility index, or DI, calculated as the minimal cross-sectional area divided by the intraballoon pressure at a set fill volume. Two versions of the device exist. EndoFLIP uses a soft balloon for measurement alone, while EsoFLIP carries a stiffer balloon that can dilate a narrowing while reporting diameter changes in real time. The technology is performed during sedated endoscopy, which is part of its appeal—it can be done in the same sitting as the diagnostic exam, without the awake catheter placement that manometry requires.


What FLIP can do has expanded well beyond a single measurement. Carlson and colleagues, working from a cohort of more than seven hundred subjects studied alongside high-resolution manometry, showed that the device could be used not just to gauge junction opening but to classify esophageal motility itself. Their approach, FLIP Panometry, watches how the esophageal body contracts in response to sustained distension—an assessment of secondary peristalsis that ordinary manometry, focused on swallow-triggered primary peristalsis, simply does not capture. By combining a contractile-response pattern with a junction-opening category, they built a classification that paralleled the Chicago Classification used for manometry. Patients with normal junction opening and a normal contractile response almost always had normal motility or ineffective motility on manometry, while those with reduced opening and a weak contractile response overwhelmingly carried a disorder of junction outflow, most often achalasia. The message was not that FLIP should replace manometry, but that the two tests illuminate different facets of esophageal function and can confirm, complement, or clarify one another, particularly when an initial manometric impression is inconclusive.


The pediatric story is younger and, in some ways, more revealing. EndoFLIP was cleared in the United States in 2019 for the esophagus, pylorus, and anal sphincters in children five years and older, and off-label use has reached infants as young as ten months. Yet the central difficulty in children is the absence of normative data. Benitez and colleagues studied one of the largest pediatric achalasia cohorts reported, measuring junction distensibility before and immediately after balloon dilation and comparing the results to non-achalasia controls. Treatment-naive children had markedly lower distensibility and smaller junction diameters than controls, and dilation produced a clear, immediate rise in DI together with improved symptom scores. But the findings also carried a caution: only half of treatment-naive children fell below the adult diagnostic threshold of 2.0 mm² per mmHg, meaning that adult cutoffs, applied uncritically, could misclassify a substantial fraction of symptomatic children. Pediatric esophagi are not simply smaller adult esophagi, and the reference ranges borrowed from adults may flatter or mislead.


Two recent reports show how far the pediatric application now reaches beyond achalasia. In eosinophilic esophagitis, where chronic inflammation can quietly remodel the esophageal wall into fibrosis and stricture, Berson and colleagues found that FLIP detected reduced distensibility even in children who were in clinical and histologic remission. Their cohort's average DI sat below the threshold often used to mark abnormal rigidity, and the histologic eosinophil count did not track with the distensibility number—an argument that biopsy and symptom assessment alone can miss residual mechanical disease that FLIP picks up. In a different vein, Hoskins and colleagues turned the probe toward vascular compression of the esophagus, the kind produced by an aberrant subclavian artery or a vascular ring. There, FLIP detected narrowing more often than endoscopy did, sometimes flagging functional restriction in a normal-looking esophagus, and just as usefully, it helped exclude meaningful obstruction in children whose symptoms turned out to stem from reflux or inflammation rather than the vessel. Paired measurements at the compression site and the lower sphincter showed convincingly reduced diameter and distensibility where the vessel pressed.


None of these papers oversells the device. Each returns to the same chorus of limitations: no standardized pediatric protocol, no validated reference values indexed to age and size, balloon and catheter constraints in the smallest patients, cost, and the concentration of expertise in a handful of centers. FLIP does not diagnose by itself; it is described, repeatedly, as a complementary or adjunctive tool, most powerful when its real-time, objective numbers are read alongside endoscopy, imaging, and manometry. Still, the trajectory is clear. A technology that lets a clinician feel the esophagus quantitatively, at the moment of endoscopy, is filling a space the older tools left empty—and as pediatric normative data accumulate, that quiet rise seems likely to continue.

References:
1- Benitez AJ, Budhu S, Burger C, Turco R, Ballester L, Shah A, Lynch K, Fiorino K, Menard-Katcher C, Muir AB, Mamula P. Use of the functional luminal imaging probe in pediatrics: A comparison study of patients with achalasia before and after endoscopic dilation and non-achalasia controls. Neurogastroenterol Motil. 33(12):e14133, 2021
2- Krasaelap A, Lerner DG. Advances in Endoscopic Procedures in Pediatric Patients. Pediatr Clin North Am. 68(6):1221-1235, 2021
3- Carlson DA, Gyawali CP, Khan A, Yadlapati R, Chen J, Chokshi RV, Clarke JO, Garza JM, Jain AS, Katz P, Konda V, Lynch K, Schnoll-Sussman FH, Spechler SJ, Vela MF, Prescott JE, Baumann AJ, Donnan EN, Kou W, Kahrilas PJ, Pandolfino JE. Classifying Esophageal Motility by FLIP Panometry: A Study of 722 Subjects With Manometry. Am J Gastroenterol. 116(12):2357-2366, 2021
4- Lerner DG, Mencin A, Novak I, Huang C, Ng K, Lirio RA, Khlevner J, Utterson EC, Harris BR, Pitman RT, Mir S, Gugig R, Walsh CM, Fishman D. Advances in Pediatric Diagnostic Endoscopy: A State-of-the-Art Review. JPGN Rep. 3(3):e224, 2022
5- Berson J, Kota A, Levine J. Endoluminal functional lumen imaging probe: a new modality in the evaluation of esophageal disorders in children and preliminary use in eosinophilic esophagitis. Front Pediatr. 13:1581225, 2025
6- Hoskins BJ, Bose P, Pitman RT. Pediatric vascular compression of the esophagus: Endoluminal functional lumen imaging probe as a complement to imaging and endoscopy. JPGN Rep. 7(2):192-199, 2026

PSU Volume 67 No 03 SEPTEMBER 2026

Midline Cervical Cleft

Midline cervical cleft is a rare congenital malformation of the ventral neck that, despite being recognized for more than a century and a half, remains unfamiliar enough to many clinicians that it is frequently overlooked or misclassified at the moment of presentation. The lesion was first documented in the mid-nineteenth century, described in greater detail in the early twentieth century under the heading of thyroglossal anomalies, and given its current name in the 1950s. Even now the total experience recorded in the world literature is modest, amounting to only a few hundred reported cases, and its true frequency is uncertain because isolated instances are often considered too trivial to publish. Available estimates place it at roughly one to two percent of congenital anterior neck defects, with one population-based approximation suggesting an occurrence on the order of one in seventy thousand births. Historically a female predominance of up to two to one was proposed, but larger pooled analyses have found the sexes affected almost equally, and one extensive review even reported a slight male excess, so that no convincing sex predilection can currently be claimed. A tendency toward higher frequency in individuals of European ancestry has been suggested but rests on limited data.


The malformation is present from birth, although its subtlety in the neonate means the diagnosis may not be made until infancy, when impaired neck mobility becomes apparent. The classic presentation is a triad. Cranially there is a small nipple-like or hood-like skin tag; along the midline there is a linear atrophic groove of dysmorphic or absent skin, most often lined by a reddened, desquamating epithelium; and caudally there is a blind-ending sinus or pit that may intermittently discharge mucoid or serous fluid. Beneath the atrophic surface lies the anatomical feature of greatest clinical importance, a fibrous cord that runs longitudinally from the region of the mandibular symphysis to the sternum or manubrium. This cord, together with the paucity of overlying skin, tethers the anterior neck, producing a web, limiting extension, and effacing the normal cervico-mental angle. Over time the traction transmitted to the developing mandible can generate a bony spur, encourage mandibular hypoplasia and retrognathia, and contribute to an open-bite tendency and an appearance of micrognathia. Not all three components of the triad are invariably present; pooled data indicate that most patients display the full triad, while a minority present with only one or two elements, the linear atrophic groove being the most consistent finding and the caudal sinus and cephalic nodule somewhat less frequent.


The embryological basis remains debated, but the most widely accepted hypothesis attributes the defect to failure of midline fusion of the first and second, and possibly the third, branchial arches during the third and fourth weeks of intrauterine development. In this model, a persistent midline furrow allows abnormal deposition and migration of mesodermal cells within the ectoderm, which then differentiate into the skeletal muscle, glandular tissue, and mucosal surface characteristic of the lesion. Competing theories have invoked a bronchogenic origin, persistence of thyroglossal remnants, vertical outgrowth of tongue musculature, pressure necrosis from the pericardial roof, and localized vascular ischemia, none of which fully accounts for the consistent anatomy or histology. The condition is regarded as a caudal variant of the number 30 facial cleft in the standard craniofacial classification, and although it is overwhelmingly sporadic, a small number of familial occurrences, including transmission between a grandparent and grandchild, have prompted genetic study. Exome analyses have suggested a polygenic contribution, with reported associations involving loss of a pregnancy-associated plasma protein and mutations affecting several candidate genes, but no single causal mutation has been established.


Histopathology varies by region of the specimen. The cephalic tag typically shows normal skin, sometimes with cartilage or muscle. The linear cleft demonstrates keratinized stratified squamous epithelium with parakeratosis and a characteristic absence of epithelial adnexa in the dermis, with fibrosis replacing the superficial musculature. The caudal tract is lined by pseudostratified ciliated columnar epithelium, at times of respiratory type, and contains seromucinous glands that explain the mucoid discharge. A more recent and clinically consequential observation is that the subcutaneous cord is not merely fibrous but frequently contains a bundle of mature striated muscle lying superficial to the platysma, in the plane normally occupied by subcutaneous fat. This contractile band, demonstrable by its response to cautery and by imaging, appears to be the true agent of neck tethering, and its previous under recognition is thought to explain many of the recurrences reported after incomplete surgery.


Because the diagnosis is essentially clinical, imaging is used chiefly to confirm the lesion and exclude concurrent pathology rather than to establish the diagnosis. Ultrasonography is the reasonable first-line modality, being noninvasive and well tolerated, and it typically shows an avascular blind-ending sinus tract with an associated fibrous band in the dermis while allowing assessment of the thyroid and adjacent structures. Cross-sectional imaging is reserved for atypical presentations, suspected associated anomalies, or surgical planning; magnetic resonance imaging characteristically reveals thinning of the epidermis and a linear tract that is hypointense on T1 and hyperintense on T2 without involvement of deep bony or cartilaginous structures. The principal entities in the differential diagnosis are thyroglossal duct cyst, which elevates with tongue protrusion and swallowing and relates to the hyoid, and branchial cleft anomalies, which are usually lateral, along with dermoid and epidermoid cysts. Associated malformations, when they occur, include clefting of the lip, mandible, tongue, or sternum, absence of portions of the hyoid or thyroid cartilage, and, more rarely, midline hemangioma and cardiac defects, so inspection of the oral cavity, tongue, and chest is prudent.


Treatment is surgical, and the cardinal principle on which the literature is unanimous is that the entire lesion, and above all the fibrous or fibromuscular cord, must be excised completely; mere transection or partial resection reliably produces recurrence and persistent contracture. Early intervention, generally advocated before one year of age and by some authors within the first months of life, is favored because the lesion is smaller and less mature, the resection and resulting scar are minimized, and growth restriction of the mandible may be limited. The closure technique remains the chief area of debate. Simple linear closure can suffice for small, immature lesions when adjacent tissue is lax and no established contracture is present, but it carries a higher risk of recurrent contracture and vertical scar banding. Consequently most surgeons employ some geometric closure, with single, double, or opposing Z-plasty being the most common, since these lengthen the contracted midline, reorient the scar into natural skin creases, and help recreate the cervico-mental angle; W-plasty has also been used successfully.


Hypertrophic scarring is the most frequently encountered complication, particularly along the limbs of a Z-plasty, while recurrence has been observed almost exclusively when excision was incomplete or a straight-line repair was chosen. Long-term morphometric follow-up suggests that after release the chin grows at a normal rate but shows no catch-up, remaining somewhat posteriorly displaced, leaving unresolved whether the retrognathia reflects an intrinsic developmental defect or the mechanical legacy of the cord.


In sum, midline cervical cleft is a rare but clinically distinctive anomaly whose recognition depends on appreciating its characteristic triad and its tethering cord. Prompt clinical diagnosis, judicious use of ultrasonography, and early complete excision of the fibrous and muscular band, followed by a tension-free geometric closure, offer reliable restoration of neck contour and mobility and minimize the functional and esthetic sequelae that otherwise accrue with age.

References:
1- D'Souza JN, Valika T, Maddalozzo J. Surgical management of midline cervical cleft. Int J Pediatr Otorhinolaryngol. 127:109657, 2019
2- Çelikoyar M, Aktan E, Dogusoy G. Congenital midline cervical cleft: a case report. J Med Case Rep. 13(1):176. 2019
3- Riba M, Bejarano M, Hernández C, Moraleda I, Massaguer C, Ribalta T, Gómez M, Krauel L, Parri FJ, Albert A. Midline Cervical Cleft: An Anatomical Finding and a Proposal for a New Approach. Cleft Palate Craniofac J. 57(12):1422–1427, 2020
4- Moreno SD, Christopher P, Kloostra P. Congenital Midline Cervical Cleft (CMCC): Z-Plasty Versus Linear Cutaneous Repair. J Craniofac Surg. 34(1):e38–e41, 2023
5- Magalhães R, Louro M, Forny D, Sá Á, Franco D. Congenital midline cervical cleft: Management of a case series and literature review. J Plast Reconstr Aesthet Surg. 93:117–126, 2024
6- Hwang JC, Perry R. Midline Cervical Cleft: Case Report and Current Understanding. Cleft Palate Craniofac J. 62(12):2180–2186, 2025

Chance Fracture

A Chance fracture is an unstable spinal injury first described in 1948 as a distinctive flexion-distraction pattern that splits the vertebra horizontally. What makes this fracture conceptually important is that it involves all three columns of the spine as defined by the three-column model. The anterior column comprises the anterior longitudinal ligament, the anterior annulus, and the anterior two-thirds of the vertebral body; the middle column includes the posterior third of the vertebral body, the posterior annulus, and the posterior longitudinal ligament; and the posterior column encompasses the posterior bony elements and the posterior ligamentous complex. Because an injury involving at least two of these three columns is considered mechanically unstable, and because a Chance fracture typically produces a distraction injury of the middle and posterior columns with or without an anterior compression component, it is by definition an unstable lesion. The horizontal fracture line propagates from posterior to anterior, coursing through the spinous process, lamina, pedicles, and into the vertebral body, without lateral displacement or rotation of the fragments.


The mechanism is a sudden deceleration of the trunk against a fixed point, most classically the lap portion of a seat belt during a motor vehicle collision. When the vehicle decelerates abruptly, the restrained pelvis remains anchored while the upper body is thrown violently forward, forcing the spine to hyperflex over the belt, which acts as a fulcrum. This generates tension across the posterior elements and, in more severe cases, compression of the anterior vertebral body. The association with lap belts, recognized in the 1960s, gave the injury its alternate name of "seat belt fracture." Although motor vehicle collisions dominate, the same flexion-distraction forces can arise from falls from height, assaults, extreme sports such as rodeo and snowboarding, and military blast events involving armored vehicles. A less familiar variant occurs iatrogenically at the ends of long spinal fusion constructs, where the pedicles split along their longitudinal axis into cranial and caudal fragments, producing proximal or distal junctional failure without any antecedent trauma.


Epidemiologically, thoracolumbar spine fractures are common, and roughly 2% of blunt trauma patients sustain one. The thoracolumbar junction is the second most frequent site of spinal injury after the cervical spine. Chance fractures classically cluster at the T10–L2 transition in adults, whereas in children they tend to occur in the mid-lumbar region. There is a male predominance and a tendency to affect children and young adults, with reported mean ages in the mid-twenties. The location difference between age groups has direct clinical consequences: children are more likely to fracture L1–L3, while adults more often fracture the thoracic spine, including levels such as T4–T6 and T10–T12 that are rarely involved in children.


The most clinically dangerous feature of Chance fractures is their strong association with intra-abdominal injury. The same belt that fractures the spine crushes the viscera between the restraint and the vertebral column, and the reported incidence of concomitant abdominal injury ranges widely from roughly a third to nearly nine out of ten cases, commonly cited as high as 50%. The most feared associated injuries are hollow viscus perforations and mesenteric lacerations, both of which carry substantial mortality. This risk is markedly higher in children. When a Chance fracture is present, pediatric patients have a concomitant intra-abdominal organ injury far more often than adults—about 63% versus 23%—and hollow viscus injury in particular is dramatically more frequent, roughly 51% versus 8%. Interestingly, rates of solid organ injury are nearly identical between children and adults, so the excess risk in children is driven specifically by bowel and mesenteric injury. This pattern holds even when the analysis is restricted to collisions alone, which argues that the difference reflects anatomy rather than mechanism. The likely explanation lies in belt positioning and body proportions: children's belts frequently ride too high across the abdomen rather than the pelvis, creating a fixation point over soft viscera, and the pediatric abdomen is more compliant with underdeveloped iliac crests. The higher rate of lumbar fractures in children mirrors this higher-riding belt. The practical result is a much greater need for surgical abdominal intervention in children.


Clinically, the injury is treacherous because patients typically present with back pain but no neurological deficit, so the fracture can be overlooked. Neurological signs appear only when there is cord or cauda equina compromise. A critical physical finding is the "seatbelt sign"—linear bruising or abrasion across the abdomen in the belt's distribution—which should sharply raise suspicion for both the fracture and underlying visceral injury, and which can also appear on CT as fat stranding in the anterior abdominal wall. The great danger is delayed presentation of bowel injury. Several documented cases illustrate a patient arriving hemodynamically stable with only subtle initial imaging findings, then deteriorating hours later as a bowel perforation or complete transection declares itself. Peritoneal signs develop slowly with small bowel injury because luminal contents are relatively neutral and bacterial load is low; a rising heart rate as part of the systemic inflammatory response may be the first physical clue. For this reason, close serial monitoring of vital signs, laboratory values, and abdominal examination is essential, with repeat CT recommended when the picture is equivocal or the patient worsens, and exploratory laparoscopy or laparotomy when perforation is suspected. In the context of fever, abdominal pain, and tachycardia in a child with a Chance fracture, the appropriate action is to proceed to the operating room out of concern for hollow viscus injury.


For diagnosis, CT is the imaging modality of choice in patients sixteen and older, superior to radiography for detecting the fracture and for evaluating associated abdominal injury; coronal and sagittal reformations are essential given the horizontal orientation. In younger children, radiography is often the recommended first study, though CT obtained for abdominal evaluation typically suffices. MRI outperforms CT for soft tissue and ligamentous injury and should be obtained when ligamentous disruption or cord compromise is suspected, because purely ligamentous Chance injuries are much harder to detect and more likely to be missed. A sternal fracture is an additional sign of instability.


Management depends on fracture displacement and the nature of the injury. A purely osseous, non-displaced fracture without neurological deficit can be treated conservatively with a rigid brace or hyperextension cast, typically for eight to twelve weeks, with high union rates. Displaced fractures with a significant bony gap, neurological deficit, or ligamentous involvement require surgery, because soft tissue injuries will not heal with bracing and instability will persist. The mainstay of surgical treatment is posterior pedicle screw fixation to reconstruct the posterior tension band, achieving realignment, reduction, and stabilization; this may be performed open or percutaneously, with fusion reserved as the final goal when ligamentous injury is present.


Reduction of kyphosis is important to prevent painful post-traumatic sagittal malalignment. Prognosis correlates with the degree of kyphosis, and outcomes after surgical stabilization are good in the great majority of patients, though residual low back pain remains a common long-term complaint. Ultimately, optimal care depends on an interprofessional team maintaining a high index of suspicion so that neither the fracture nor its dangerous abdominal companions are overlooked.

References:
1- Bourghli A, Obeid I, Boissiere L, Vital JM, Tabboush Z, Al Sarawan M. Management of a high thoracic chance fracture. Eur Spine J. 27(7):1547–1552, 2018
2- Hazen BJ, Keane OA, Vandewalle RJ, Grady Z, Wetzel M, Chern JJ, Santore MT. Difference in Presentation and Concomitant Intra-Abdominal Injury with Chance Fracture in Pediatric and Adult Populations. Am Surg. 89(6):2486–2491, 2023
3- Comadoll SM, Holton KJ, Polly DW Jr, Schmitz MW, Haselhuhn JJ, Soriano PBO, Martin CT, Jones KE, Sembrano JN. Chance Fracture Pattern Presenting in Proximal Junctional Failure. J Am Acad Orthop Surg Glob Res Rev. 7(8):e23.00039, 2023
4- Koay J, Davis DD, Hogg JP. Chance Fractures. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Aug 14.
5- Destinval C, Larmure O, Journeau P, Lemelle JL. Seat belt syndrome with caecal perforation and Chance fracture in an adolescent. BMJ Case Rep. 16(10):e254631, 2023
6- Huang CK, Lee CC, Kwok CM. Chance fracture at L2 followed by delayed jejunal transection due to a motor vehicle collision: A case report and review. Trauma Case Rep. 48:100968, 2023

Minimally Invasive Repair Pectus Excavatum

Pectus excavatum is the most common congenital chest wall deformity, characterized by a posterior depression of the sternum and adjacent costal cartilages that gives the chest a sunken appearance. It occurs in approximately one in every 300 to 400 live births and shows a marked male predominance, affecting boys roughly four to five times more often than girls. This apparent sex disparity may be partly artificial, as breast tissue can conceal the severity of the defect in female patients, leading to underdiagnosis. The deformity typically becomes more pronounced during the pubertal growth spurt, when rapid skeletal development accentuates the depression, and the chest wall becomes progressively less flexible as the patient ages.


The clinical significance of pectus excavatum spans a spectrum from a purely cosmetic concern to a source of meaningful cardiopulmonary compromise. The inward displacement of the sternum most commonly compresses the right-sided chambers of the heart, displacing the heart toward the left chest and reducing stroke volume, cardiac output, and both diastolic and systolic function. Many patients report exercise intolerance, fatigue, dyspnea on exertion, palpitations, and chest pain, and functional testing frequently demonstrates reduced maximal oxygen consumption. Historically the condition was dismissed as a cosmetic problem alone, but accumulating evidence now shows that cardiac performance may be reduced measurably and that surgical correction can restore normalized cardiopulmonary function. Importantly, the psychosocial burden should not be discounted; body image concerns, diminished self-confidence, social avoidance, anxiety, and depression are all well documented, and quality-of-life measures improve substantially following repair.


For roughly half a century, surgical correction relied on open techniques involving resection of the deformed costal cartilages, sometimes combined with a sternal osteotomy, to reposition the sternum. This open approach, refined over decades, remained the standard until the late 1990s, when a minimally invasive technique was introduced. This method requires no cartilage resection or sternal osteotomy. Instead, a curved metal bar is passed behind the sternum under thoracoscopic guidance and rotated so that its convexity elevates the depressed area from within. The bar is secured to the chest wall and left in place for a period of years while the chest remodels, after which it is removed. The minimally invasive procedure rapidly became the standard of care, particularly for pediatric and adolescent patients, owing to its smaller incisions, shorter operative time, minimal blood loss, and excellent cosmetic outcomes. Its adoption fueled a dramatic rise in the number of patients seeking correction, driven in part by greater awareness spread through the internet.


Preoperative assessment combines clinical examination with imaging. Thoracic imaging, using either computed tomography or magnetic resonance imaging, allows measurement of the Haller index, calculated by dividing the transverse diameter of the chest by the anteroposterior distance between the sternum and spine at the deepest point. A value above 3.2 to 3.25 has traditionally justified surgical repair, though this threshold has notable limitations. Abnormal values can appear in otherwise normal chests, and some severely affected patients fall below the cutoff, so the index does not correlate reliably with physiologic symptoms. The correction index has emerged as a more accurate estimate of severity. Additional evaluation may include electrocardiography, echocardiography, pulmonary function testing, and cardiopulmonary exercise testing, particularly when comorbidity such as a connective tissue disorder is suspected or when the case is more complex. Metal allergy screening is advisable when there is a personal or family history of allergic reactions, since the standard bars contain nickel and other components that can provoke sensitization.


The optimal timing of surgery remains debated. Many surgeons prefer to operate near the onset of puberty, when the chest wall remains soft, elastic, and easily manipulated, with broad agreement that the best results are obtained between roughly 13 and 16 years of age. Operating too early carries a higher risk of recurrence if the bar is removed before puberty, while adult repair, though feasible, is technically more demanding. The calcification and rigidity that accompany aging make sternal elevation more difficult, increase the force distributed to the bars, and raise the risk of bar displacement. Nevertheless, successful repair has been reported in patients well into their seventies, and adult correction continues to increase, with symptom resolution and satisfying cosmetic results achievable when appropriate technical modifications are applied.


Several modifications have improved the safety and durability of the procedure. Routine thoracoscopy provides direct visualization during the retrosternal dissection and has become widely accepted as a minimum standard to reduce cardiac injury, the most feared and potentially lethal complication. Cardiac perforation is most likely during dissection in patients with previous open cardiac surgery, in whom dense adhesions bind the sternum to the myocardium, and in those with very deep or stiff chests. Sternal elevation techniques—including crane systems, retractors, subxiphoid approaches, hooks, and the vacuum bell applied intraoperatively—expand the retrosternal space and facilitate safe bar passage, further decreasing the incidence of near-fatal events. The use of multiple bars distributes corrective forces across a broader area, improves correction in stiff or complex chests, and reduces displacement. The cross-bar technique, in which two bars are crossed beneath the sternum with their lateral ends resting on the lower rib cage, is particularly useful for severe deformities with costal flaring, avoiding lateral chest wall depression while correcting flaring.


Bar stability depends heavily on correct positioning. The bar must enter and exit the chest medial to the highest point of the deformity; if placed too laterally, it fails to elevate the sternum and may strip the intercostal muscles, leading to instability and recurrence. Numerous fixation strategies—lateral and medial stabilizers, pericostal sutures, multipoint suture fixation, hinge plates, and claw fixators—have reduced the rate of bar displacement from historical highs to around one percent. Shorter bars have also been adopted to reduce the risk of flipping.


Complications, though relatively uncommon in experienced hands, span a range of severity. Pleural effusion and pneumothorax are almost universally present but rarely require intervention. Bar displacement, once the most common late complication, has fallen dramatically with improved fixation. Overcorrection into a carinatum shape, metal allergy, wound infections, and, rarely, life-threatening hemorrhage from mediastinal or internal mammary vessels can occur. Notably, serious complications can arise not only during placement but also during bar removal, which should therefore be performed in a setting equipped to manage catastrophic bleeding. Recurrence rates remain low when bars are left in place for an adequate interval, generally two to three years or longer in complex cases.


Postoperative pain is the defining challenge of this operation. Paradoxically, despite its minimally invasive nature, the procedure may cause more pain than its open counterpart, because the substernal bar exerts sustained upward force on an intact chest wall and acutely stretches the intercostal nerves until bone and cartilage remodel. Pain and opioid-related side effects are the principal determinants of hospital length of stay, making effective analgesia central to recovery. Traditional approaches relied on thoracic epidural analgesia and patient-controlled analgesia, but these have limitations including variable efficacy, prolonged stays, and complications. Modern practice emphasizes multimodal, opioid-sparing strategies. Regional techniques—including paravertebral, erector spinae plane, serratus anterior plane, and intercostal nerve blocks—and non-opioid adjuncts such as acetaminophen, nonsteroidal anti-inflammatory drugs, gabapentinoids, ketamine, dexmedetomidine, and methadone all contribute.


The most transformative advance has been intercostal nerve cryoablation, which induces temporary degeneration of the intercostal nerve axons, halting pain transmission for weeks until regeneration occurs. Cryoablation has been shown to reduce hospital stay substantially—in one randomized trial from around five days to three—and to decrease opioid consumption compared with epidural analgesia. Its main limitation is a delayed onset of up to a day, so it is best combined with a direct-acting regional block or systemic analgesia to bridge the early postoperative period. When cryoablation is paired with an adjunct analgesic intervention, it appears superior to all other modalities in shortening hospitalization, and refined multimodal protocols have made same-day discharge feasible for a majority of patients. Neuropathic pain is a recognized risk, more common in adults than children, but rarely requires treatment.


The incorporation of these techniques into enhanced recovery pathways—combining preoperative education, multimodal analgesia, early mobilization, early oral intake, and prompt removal of catheters—has standardized care and improved outcomes. Even so, roughly one-third of patients require a short course of opioids in the immediate postoperative period. Together, these surgical and analgesic refinements have made minimally invasive repair of pectus excavatum a safe, effective, and increasingly well-tolerated operation with excellent long-term cosmetic and functional results.

References:
1- Pilegaard H, Licht PB. Minimal Invasive Repair of Pectus Excavatum and Carinatum. Thorac Surg Clin. 27(2):123-131, 2017
2- Goretsky MJ, McGuire MM. Complications associated with the minimally invasive repair of pectus excavatum. Semin Pediatr Surg. 27(3):151-155, 2018
3- Haecker FM, Krebs TF, Kleitsch KU. Current Development of Minimally Invasive Repair of Pectus Excavatum (MIRPE). Children (Basel). 9(4):478, 2022
4- Aly MR, Farina JM, Botros MM, Jaroszewski DE. Minimally invasive repair of pectus excavatum in adults: a review article of presentation, workup, and surgical treatment. J Thorac Dis. 15(9):5150-5173, 2023
5- Brussels AR, Kim MS. Perioperative considerations in anesthesia for minimally invasive repair of pectus excavatum, Nuss procedure. Semin Pediatr Surg. 33(5):151459, 2024
6- Chiu MZ, Li R, Koka A, Demehri FR. Pain management after pediatric minimally invasive repair of pectus excavatum: a narrative review. Transl Pediatr. 13(12):2267-2281, 2024
7- Van Polen EJ, Franssen CJ, Daemen JHT, Isabella AJ, Franssen AJPM, Hulsewé KWE, Vissers YLJ, de Loos ER. Postoperative Pain Management After Minimally Invasive Repair of Pectus Excavatum: A Systematic Review and Network Meta-analysis. J Pediatr Surg. 60(6):162282, 2025

PSU Volume 67 No 04 OCTOBER 2026

Testicular Microlithiasis

Testicular microlithiasis (TM) is an ultrasonographic finding characterized by scattered calcium deposits within the seminiferous tubules. It appears as punctate, hyperechogenic foci, typically no larger than 1 to 3 mm, that do not produce posterior acoustic shadowing, a feature that distinguishes it from other testicular calcifications with different clinical significance. Its characteristic appearance, sometimes described as a "snowstorm" pattern, is usually identified incidentally during scrotal ultrasound performed for unrelated reasons, since the condition is painless and impalpable on physical examination. Since its first radiological description in a four-year-old boy in the early 1970s, and its later characterization by ultrasound years afterward, clinical interest in TM has steadily grown, driven largely by the uncertainty surrounding its possible association with testicular malignancy.


Histologically, TM is defined by the presence of laminated calcifications within the seminiferous tubule—rounded bodies made up of concentric rings that, according to the most widely accepted hypotheses, originate from the inability of Sertoli cells to fully phagocytose degenerated germ cell debris. This unremoved cellular material is thought to act as a nidus onto which glycoproteins and calcium salts progressively deposit, eventually forming the microcalcospherites visible on pathology. Other hypotheses point to local disturbances in mineral metabolism, genetic factors, or hormonal imbalances that impair androgen stimulation of Sertoli cells. None of these explanations is considered definitive, and the fact that laminated calcifications can also be found in histologically normal testes—as well as in cryptorchid testes or those harboring germ cell tumors—complicates the interpretation of their exact origin.


Radiologically, the diagnosis is established when five or more hyperechogenic foci are identified in a single ultrasound image, defining classic TM; below that threshold, the finding is termed limited TM. Distribution may be diffuse or focal, and involvement can be unilateral or bilateral, although in the pediatric population bilateral involvement and the classic pattern consistently predominate. This classification, while descriptively useful, does not substantially change follow-up recommendations, since current guidelines do not differentiate management based on subtype.


The prevalence of TM in children varies widely depending on the population studied, the diagnostic definition used, and the frequency of the transducer employed. Taken together, pediatric studies place the prevalence at approximately 2% in symptomatic children referred for ultrasound and somewhat above 4% in asymptomatic children, with a tendency to increase with age and with more recent publication dates, likely reflecting the greater resolution of current ultrasound equipment. These figures are roughly comparable to those reported in asymptomatic young adults. TM is more frequently associated with certain benign conditions, such as undescended testis—where its prevalence can range from about 3% to 12%—a history of orchidopexy, varicocele, and hypospadias. A markedly elevated prevalence has also been described in children with Down syndrome, Klinefelter syndrome, and, particularly strikingly, McCune-Albright syndrome, where some series report figures above 20% and even close to 60%. Whether these associations reflect a genuine causal relationship or simply the fact that these patients are more likely to undergo repeated ultrasound studies remains unknown.


The most debated aspect of TM continues to be its relationship with testicular germ cell tumors. In adults, several systematic reviews have found an increased relative risk of testicular neoplasia in the presence of TM, particularly in subgroups with additional risk factors such as cryptorchidism, subfertility, or a personal history of testicular tumor; in contrast, asymptomatic patients without risk factors show no such increase. In the pediatric population, the picture is less clear. Large follow-up series agree that the vast majority of children with TM remain free of neoplasia during the observation period, with new tumor rates below 1% in most cohorts, although at least one large multicenter study has reported testicular tumor rates several times higher in children with TM compared with those without it, keeping the controversy open. One factor that complicates interpretation of these findings is the short duration of follow-up in most pediatric studies—usually between six months and a few years—which rarely extends beyond puberty, the point at which the incidence of germ cell tumors naturally begins to rise. In other words, a substantial part of the relevant risk window simply has not yet been observed in the children included in these studies.


When tumors have been reported concurrently with TM in prepubertal children, most are benign or premalignant lesions, and they are frequently associated with identifiable risk factors such as cryptorchidism or predisposing genetic syndromes. Frankly malignant tumors are far more common in adolescents older than thirteen years, an age at which the risk profile begins to approach that of young adults. Furthermore, the course of TM itself during childhood appears largely stable: in series with repeated ultrasound follow-up, only a minority of testes show a significant increase in microlith count, and a non-negligible proportion show a reduction or even complete resolution of the finding over time. No studies have been specifically designed to assess whether TM diagnosed before puberty is associated with infertility in adulthood, a gap that recent reviews highlight as a priority for future research.


Given this uncertainty, both European and American societies agree on one central point: isolated TM, without additional risk factors, does not require systematic ultrasound follow-up or routine serum tumor marker testing—measures that have not been shown to change outcomes and that, conversely, may generate unwarranted anxiety for the patient and family, along with unnecessary cost and exposure. Differences emerge when additional risk factors are present—cryptorchidism, testicular atrophy, a personal or family history of testicular tumor, or predisposing genetic syndromes. European bodies tend to recommend periodic, generally annual, ultrasound surveillance along with education on self-examination from puberty onward; American guidelines instead prioritize education and monthly self-examination, reserving ultrasound for suspicious clinical findings, without establishing a formal imaging surveillance program. Both frameworks emphasize the importance of prompt ultrasound access when self-examination detects a change, as well as the need to plan the transition of pediatric patients with TM and risk factors to adult urology care upon reaching the age of majority, since it is precisely in that later stage that the risk of malignancy appears to become more clearly established.


Taken together, current evidence repositions childhood testicular microlithiasis as a generally benign and often transient finding, rather than a reliable marker of imminent oncologic risk. Its management should be individualized according to clinical context: reassurance and education in isolated cases, and closer—though not excessive—clinical surveillance in children who also present recognized risk factors. Fundamental questions remain unresolved, including whether TM detected in childhood represents the same biological entity observed in adults, what its true impact on future fertility might be, and whether extended follow-up beyond puberty would change current conclusions about malignancy risk. Answering these questions will require prospective, multicenter studies with follow-up extending into adulthood, something the literature available to date still lacks.

References:
1- Yu CJ, Lu JD, Zhao J, Wei Y, Zhao TX, Lin T, He DW, Wu SD, Wei GH. Incidence characteristics of testicular microlithiasis and its association with risk of primary testicular tumors in children: a systematic review and meta-analysis. World J Pediatr. 16(6):585-597, 2020
2- Hoen LA, Bhatt NR, Radmayr C, Dogan HS, Nijman RJM, Quaedackers J, Rawashdeh YF, Silay MS, Tekgul S, Stein R, Bogaert G. The prognostic value of testicular microlithiasis as an incidental finding for the risk of testicular malignancy in children and the adult population: A systematic review. On behalf of the EAU pediatric urology guidelines panel. J Pediatr Urol. 17(6):815-831, 2021
3- Sag S, Elemen L, Masrabaci K, Gungormez EK. Is testicular microlithiasis associated with testicular pathologies in children? Pediatr Surg Int. 38(9):1317-1319, 2022
4- Flores HA, Bailey WC, Harris KT. Management of pediatric testicular microlithiasis. Front Pediatr. 13:1588261, 2025
5- Zitouni H, Dghaies R, Kechiche N, Mhiri R. Pediatric testicular microlithiasis: a review of epidemiology, risk associations and management. Front Pediatr. 13:1553825, 2026

Balanitis Xerotica Obliterans

Balanitis xerotica obliterans (BXO) is widely recognized as the male genital manifestation of lichen sclerosus, a chronic, progressive, sclerosing inflammatory dermatosis of unclear etiology that most commonly affects the foreskin, glans, and external urethral meatus in boys, and which may, when neglected, extend into the peripheral urethra, penile skin, and scrotum. The condition was first described in the nineteenth century under the term lichen sclerosus of the glans and prepuce, and the internationally adopted designation of balanitis xerotica obliterans was proposed several decades later to capture its three cardinal features: chronic inflammation of the glans (balanitis), a whitish, atrophic epithelial appearance (xerotica), and an obliterative endarteritis. Although initially considered a disease of adulthood, its occurrence in children was documented by the mid-twentieth century, and it is now understood to be the leading cause of secondary, pathological phimosis in the pediatric population, distinguishing it from the far more common physiological non-retractility of the prepuce that resolves spontaneously with growth.


The true incidence of BXO in children remains difficult to establish. Population-based estimates from several countries place the prevalence at well under one percent of boys, generally in the range of roughly 0.1 to 0.4 percent, although figures differ according to region, circumcision practices, and how rigorously foreskins are submitted for histological examination. When the denominator is restricted to boys undergoing surgery specifically for phimosis, however, the proportion found to have BXO rises dramatically, with reported rates spanning from a small single-digit percentage to well over a third of cases, and in some surgical series approaching or exceeding forty percent. This wide variability reflects differences in diagnostic thresholds, in the routine (or selective) use of histology, and in the degree of clinical vigilance exercised by both referring practitioners and operating surgeons. A recurring theme across the literature is that incidence figures have risen over recent decades, a trend attributed less to a true increase in disease frequency than to greater awareness among clinicians, more consistent histological confirmation, and closer scrutiny of resected foreskins. The average age at diagnosis clusters around seven to nine years, though cases have been reported across the full pediatric age range, and there is ongoing debate about whether the disease is genuinely rarer in children under five years of age or whether it is simply under-recognized in that younger group, since developmental preputial adhesions are a common and usually benign cause of non-retractility at that age.


The etiology of BXO remains incompletely understood but is generally regarded as multifactorial, involving genetic predisposition, autoimmune mechanisms, and chronic local irritation, with infectious causes proposed but never convincingly substantiated. Histopathological and molecular studies have identified an infiltrate of autoreactive cytotoxic T lymphocytes, altered extracellular matrix metabolism, and dysregulated expression of cytokines and growth factors involved in fibrosis and tissue remodeling, alongside reduced expression of proteins that normally maintain epithelial integrity. Associations have been reported with atopic disease, obesity, and, less consistently, autoimmune conditions such as thyroiditis, vitiligo, and celiac disease, as well as with mechanical trauma from repeated forceful retraction of the foreskin, a phenomenon reminiscent of the Köbner effect seen in other lichenoid dermatoses. A modest proportion of affected boys also have coexisting hypospadias, and phototype has been suggested as a risk modifier, though the evidence here is mixed and sometimes contradictory.


Clinically, the disease typically announces itself as a progressively worsening, secondary phimosis in a foreskin that was previously retractile, often accompanied by ballooning during micturition, dysuria, and, on inspection, a pearly white, sclerotic, circumferential scar at the tip of the prepuce with variable degrees of erythema, fissuring, or telangiectasia. When the glans can be visualized, pallor and thickening of its surface may be evident, and in a meaningful minority of cases the urethral meatus itself is strictured or discolored. Symptom duration before presentation commonly spans several months, and behavioral changes, constipation, or voiding difficulty may be the presenting complaint in younger children who cannot otherwise articulate genital discomfort. Despite this recognizable clinical picture, the correlation between clinical impression and histological confirmation is strikingly inconsistent across studies, with reported concordance ranging from roughly half to nearly ninety percent, and sensitivity of clinical examination alone often falling below fifty percent even when specificity is high. Combining physical findings with a history of recurrent balanitis, urinary tract infection, or coexisting allergic or autoimmune disease substantially improves specificity and positive predictive value, in some analyses approaching certainty, but only at the cost of markedly reduced sensitivity, meaning that a substantial fraction of true cases could be missed if reliance were placed on history and examination alone. This asymmetry underlies the near-universal recommendation that histological examination of the excised foreskin remains essential for definitive diagnosis, since the absence of supportive history or overt scarring cannot reliably exclude the condition, while conversely, a considerable share of foreskins removed on clinical suspicion of BXO ultimately show only nonspecific chronic inflammation rather than the classic changes of hyperkeratosis, basal epidermal atrophy, homogenized subepidermal collagen with edema, loss of elastic fibers, and a band-like lymphocytic infiltrate.


At the same time, evidence suggests that general practitioners and other primary referrers continue to struggle with distinguishing pathological from physiological phimosis, resulting in a large proportion of circumcision referrals that prove, on specialist assessment, to be unnecessary, alongside a smaller but persistent problem of over-diagnosis by surgeons that risks subjecting some children to circumcision for healthy or merely inflamed, non-BXO foreskins. Both diagnostic inaccuracy and over-caution carry costs, whether measured in unnecessary procedures, delayed appropriate treatment, or the resource burden on health systems, and this tension has motivated calls for clearer commissioning guidance and continued clinician education.


Left untreated or inadequately managed, BXO follows a chronically progressive or relapsing course with scarring, potential contraction of the frenulum, and, in more advanced disease, meatal or urethral stenosis that can produce obstructed flow, acute or chronic urinary retention, and, rarely, retrograde renal damage. Even after treatment, meatal stenosis remains a recognized complication, occurring in a meaningful minority of boys who undergo circumcision, and a smaller proportion require subsequent surgical intervention such as meatotomy, meatoplasty, or, in severe urethral involvement, reconstruction using buccal mucosal grafts. In adulthood, BXO carries a small but non-negligible risk of malignant transformation to squamous cell carcinoma or related lesions, reported in a low single-digit to high single-digit percentage of cases over long latency periods, which underpins recommendations for continued surveillance into adult life.


Circumcision with complete resection of the affected foreskin remains the most widely endorsed definitive treatment, generally curative in the great majority of patients and associated with a low rate of phimosis recurrence when performed thoroughly. Nevertheless, growing recognition of the psychological and cultural importance many families place on foreskin preservation has spurred interest in alternatives. Topical corticosteroids, most commonly potent formulations such as betamethasone or mometasone applied twice daily for several weeks, have demonstrated genuine, statistically significant symptomatic improvement in randomized and observational studies, particularly in mild to moderate disease, though efficacy diminishes in severe or long-standing cases and long-term recurrence data remain limited. Topical calcineurin inhibitors such as tacrolimus and pimecrolimus offer a steroid-sparing option with a favorable side-effect profile on mucosal skin, generally reserved as second-line therapy or adjuncts after incomplete response to steroids. Surgical alternatives to full circumcision, notably preputioplasty combined with intralesional triamcinolone injection, have shown comparable patient satisfaction and, in feasibility trials, an acceptable safety profile with no observed increase in meatal stenosis, making them an appealing option for families seeking to avoid complete foreskin removal, although uptake remains limited by unfamiliarity among surgeons and the absence of formal endorsement in existing commissioning guidance. Ultimately, the management of BXO in children requires balancing definitive surgical cure against the desire for foreskin preservation, underpinned by vigilant histological confirmation, structured follow-up to detect meatal and urethral complications early, and long-term surveillance given the disease's chronic and potentially premalignant nature.

References:
1. Boksh K, Patwardhan N. Balanitis xerotica obliterans: has its diagnostic accuracy improved with time? JRSM Open. 8(6):2054270417692731. PMCID: PMC5464383, 2017
2. Nguyen ATM, Holland AJA. Balanitis xerotica obliterans: an update for clinicians. Eur J Pediatr. 179(1):9-16, 2020
3. Leganés Villanueva C, Gander R, Royo Gomes G, Ezzeddine Ezzeddine M, López Paredes M, Asensio Llorente M. Treatment of balanitis xerotica obliterans in pediatric patients. Cir Pediatr. 33(2):79-83, 2020
4. Ghidini F, Virgone C, Pulvirenti R, Trovalusci E, Gamba P. Could a careful clinical examination distinguish physiologic phimosis from balanitis xerotica obliterans in children? Eur J Pediatr. 180(2):591-59, 2021
5. Lansdale N, Arthur F, Corbett HJ. Circumcision versus preputioplasty for balanitis xerotica obliterans: a randomised controlled feasibility trial. BJU Int. 128(6):759-765, 2021
6. Gkalonaki I, Anastasakis M, Psarrakou IS, Patoulias I. Balanitis xerotica obliterans: an underestimated cause of secondary phimosis. Folia Med Cracov. 61(4):93-100, 2021

E-Bykes

In barely a decade, electric bicycles have gone from a niche market product to one of the fastest-growing modes of transport in the world. Their ability to combine human effort with motorized assistance has made them an attractive tool both for everyday mobility and for physical activity, but this same growth has brought with it a growing body of evidence on specific risks that deserves to be examined together.


One of the pioneering investigations on the subject, carried out through surveys of thousands of e-cyclists in a German-speaking European country, revealed that single-vehicle crashes—that is, falls or loss of control without a collision with another road user—constitute the most frequent type of incident among users of these bicycles. Practically one in six surveyed cyclists had experienced this type of accident since they began using their electric bicycle. The most common mechanisms included skidding on wet or icy surfaces, falling while crossing curbs or uneven surfaces, getting caught in tram tracks, and evasive maneuvers to avoid obstacles or other road users. Interestingly, the risk of this type of accident did not depend on age, but rather on factors such as being male, high exposure from frequent use, and using the bicycle mainly for commuting to work. However, when the severity of injuries was analyzed, the picture changed: women, older people, and those who perceived themselves as less physically fit had a higher risk of serious injury, a finding that suggests the factors determining the likelihood of an accident are not necessarily the same as those determining its severity.


This distinction between accident risk and severe injury risk repeats itself, with interesting nuances, in a Scandinavian study based on three independent surveys with more than seven thousand participants. There it was found that, overall, electric bicycles showed a slightly higher accident risk than conventional bicycles, but this increase was almost entirely explained by women: among men there was no difference at all between the two types of vehicle. Part of this additional risk in women appeared to be related to unfamiliarity with the vehicle, given that electric bicycles tend to attract a newer cycling public, and prior experience with the bicycle proved to be a robust predictor of accident likelihood. Nevertheless, neither injury severity nor the proportion of accidents requiring medical attention differed significantly between conventional and electric bicycles, leading to the conclusion that the latter are not inherently more dangerous, but rather that their appeal to new users could explain much of the observed risk.


A different picture emerges when examining the Asian context, where electric bicycles are not a recreational add-on but the primary urban transport mode for hundreds of millions of people. An extensive literature review on risky riding behaviors in that setting identified riding patterns markedly different from European ones: illegal occupation of motor vehicle lanes, speeding, running red lights, carrying passengers irregularly, and riding against traffic emerge as the most common infractions and those most associated with crashes. Psychological and demographic factors—age, gender, risk perception, safety attitude, and tolerated waiting time at a traffic light—proved decisive in the likelihood of committing these infractions. This analysis underscores that the electric bicycle phenomenon cannot be understood uniformly on a global scale, since regulation, infrastructure, and road culture in each region substantially shape behaviors and, therefore, risks.


The pediatric population emerges as a group of particular concern in several recent analyses. A study based on a national injury surveillance system in a North American country documented that, while injuries associated with conventional bicycles declined steadily over the decade analyzed, those associated with electric bicycles increased consistently over the same period. Males accounted for the vast majority of these injuries, and the most affected age group corresponded to preteens and adolescents. Beyond frequency, severity proved especially concerning: electric bicycle injuries required hospitalization notably more often than conventional bicycle injuries or even light combustion-powered motorized vehicles, and showed higher rates of internal injuries and fractures. Added to this is an alarming finding on prevention: in cases where helmet use could be determined, the vast majority of children injured on electric bicycles were not wearing one, a proportion far higher than that observed among conventional cyclists.


Another risk, less discussed but increasingly documented, stems not from riding itself but from the technology powering these vehicles. A review focused on burns associated with personal mobility devices, including electric bicycles, identified thermal runaway in lithium-ion batteries as a recurrent cause of fires and explosions. Hospital cohorts from various Asian cities showed patterns of severe burns, with extensive body surface areas affected and, in some pediatric cases, an injury pattern pointing to a problem of children's accessibility to defective or mishandled batteries. Combustion tends to occur during prolonged or unsupervised charging, and uncertified conversion kits—which transform conventional bicycles into electric ones through DIY methods—represent an additional risk factor repeatedly flagged.


Against this set of risks, there is also a robust body of evidence on the benefits these bicycles bring to public health and the environment, particularly in the context of active commuting to work. A recent review focused on Europe synthesizes how these vehicles allow classic barriers to conventional cycling to be overcome, such as long distances, poor physical fitness, or steep terrain, thereby facilitating the adoption of physical activity among populations that would otherwise remain sedentary. The reviewed studies show improvements in cardiorespiratory capacity after just a few weeks of regular use, metabolic benefits comparable to some extent to those of traditional cycling, and a substantial reduction in carbon dioxide emissions when these vehicles replace trips previously made by car. However, the same review acknowledges that adoption remains low and uneven across the continent, constrained by the high purchase price, lack of charging and secure parking infrastructure, and a social perception that still associates the use of electric assistance with a form of cheating or insufficient effort.


Considering these findings together, a nuanced picture emerges. The electric bicycle is not uniformly more dangerous than the conventional one, but it is not equivalent in every respect either: its higher average speed, additional weight, and capacity to attract inexperienced users—among them women new to cycling and minors—appear to concentrate much of the differential risk observed across studies. The most frequently cited accident mechanisms, such as skidding, loss of balance, and falls when crossing uneven surfaces or rail tracks, are not exclusive to electric propulsion, but the higher speed achieved with less effort could intensify their consequences. Added to this is a distinct technological risk, tied to battery safety, that requires regulatory attention independent of purely road-related aspects.


Taken together, the available evidence suggests that maximizing the benefits of these bicycles—in terms of health, reduced pollution, and urban decongestion—without disproportionately shifting their risks onto the most vulnerable users will require simultaneous progress on several fronts: road infrastructure adapted to higher circulation speeds, effective policies to promote helmet use, stricter standards for batteries and chargers, and educational strategies specifically targeting new users and minors, without which the accelerated growth of this mode of transport could continue to be accompanied by a parallel increase in the burden of associated injuries.

References:
1- Hertach P, Uhr A, Niemann S, Cavegn M. Characteristics of single-vehicle crashes with e-bikes in Switzerland. Accid Anal Prev. 117:232-238, 2018
2- Ma C, Yang D, Zhou J, Feng Z, Yuan Q. Risk Riding Behaviors of Urban E-Bikes: A Literature Review. Int J Environ Res Public Health. 16(13):2308, 2019
3-  Fyhri A, Johansson O, Bjørnskau T. Gender differences in accident risk with e-bikes-Survey data from Norway. Accid Anal Prev. 132:105248, 2019
4- Goodman LF, Birnbaum Flyer Z, Schomberg J, Maginas M, Wallace E, Vukcevich O, Awan S, Gibbs D, Nahmias J, Guner YS. Electric bicycles (e-bikes) are an increasingly common pediatric public health problem. Surg Open Sci. 14:46-51, 2023
5- Warner-Levy J, Herieka M, Sheikh Z. Riding Toward Danger: A Scoping Review of Burns Associated With Personal Mobility Devices, Including Electric Bikes (E-Bikes) and Electric Scooters (E-Scooters). J Burn Care Res. 45(5):1154-1159, 2024
6- Sampieri A, Paoli A. Incorporating active commuting into daily life: a narrative review of e-bikes' impact on health and urban air quality. Front Sports Act Living. 7:1662076, 2025


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