PSU Volume 64 No 01 JANUARY 2025

Palliative Care in Pediatric Surgery

Palliative care in pediatric surgery has developed considerably over the past decade, shifting from a traditional focus on end-of-life support to a broader integration that enhances the quality of life for young patients facing complex and often life-limiting conditions. This evolution acknowledges that palliative care (PPC) in pediatrics should not be limited to terminal care but serve as an essential component throughout the continuum of a child's surgical journey, including symptom management, psychological support, and ethical decision-making.


Historically, PPC in pediatric surgery was underemphasized, partly due to the misconception that palliative care equated to giving up hope for a cure. This perception began to shift with the American Academy of Pediatrics' 2000 guidelines, which emphasized adding life to a child's years rather than simply prolonging life. Pediatric surgeons often navigate challenging ethical considerations, balancing their commitment to life-prolonging interventions with the realities of quality of life in conditions that are not always curable. Surgeons are uniquely positioned to assess whether a surgical intervention might alleviate symptoms or enhance a child's comfort. However, this often requires realistic and sensitive conversations with families who may feel conflicted between pursuing aggressive interventions and protecting their child from additional suffering.


In pediatric oncology, where palliative care has gained notable integration, PPC aims to manage both the immediate symptoms related to cancer and the lasting effects of treatment. Despite advancements in survival rates, pediatric cancer remains a leading cause of mortality beyond infancy. Many children with cancer endure significant symptom burdens, including chronic pain, fatigue, and emotional distress, which palliative care can effectively address. Studies have shown that even as survival rates improve, a significant number of survivors face debilitating long-term effects, such as organ dysfunction, cognitive impairments, and secondary malignancies. These realities position PPC not only as an end-of-life intervention but as a necessary part of the child's cancer treatment, ensuring comfort and symptom relief regardless of prognosis.


One of the critical roles that PPC plays in pediatric oncology is in symptom management. For children with advanced cancer, surgical palliative interventions often alleviate physical symptoms like bowel obstruction, respiratory distress, and severe pain, all of which significantly impact a child's quality of life. The literature highlights cases where surgical palliative interventions have reduced pain or prevented complications, such as respiratory support surgeries or procedures to relieve severe gastrointestinal symptoms. These interventions, often conducted in collaboration with palliative care teams, are part of a multidisciplinary approach where PPC aids in assessing risks, guiding parents through options, and helping set realistic expectations about what surgery might or might not achieve.


In pediatric urology, the focus on PPC has emerged more recently. Conditions such as congenital lower urinary tract obstruction, neurogenic bladder dysfunction, and exstrophy-epispadias complex often demand repeated surgeries, intensive hospital stays, and chronic symptom management. Incorporating palliative care in pediatric urology means addressing not only the physical symptoms but also the psychosocial issues children and families face as a result of these lifelong conditions. PPC provides critical support for children undergoing complex urologic procedures, helping manage chronic pain and providing resources for families to navigate the ongoing care that often extends well into adolescence.


Moreover, prenatal palliative interventions have become a significant component in maternal-fetal surgery. The availability of early diagnostics has allowed physicians to identify severe congenital conditions such as congenital diaphragmatic hernia (CDH) prenatally, providing families with the option of maternal-fetal surgery. This third option complicates traditional decision-making, which previously offered only termination or post-birth interventions. Maternal-fetal surgery exemplifies PPC's role in improving life outcomes through early, targeted interventions. The palliative care team's involvement in these cases is invaluable, guiding families through the decision-making process by weighing potential benefits and risks while considering quality-of-life outcomes for the child. PPC professionals work alongside fetal surgeons, genetic counselors, and neonatologists, providing a well-rounded approach that respects both the parents' hopes, and the practical realities associated with these surgeries.


One of the most pressing issues in pediatric surgical palliative care is timing. Surgeons and PPC physicians frequently differ in opinions on when PPC should be introduced. PPC professionals advocate for early involvement, ideally at diagnosis, to set the foundation for comprehensive, long-term care that includes symptom management and anticipatory guidance. In contrast, many surgeons only initiate PPC consultations when the child's condition deteriorates, making curative treatment unlikely. This discrepancy in timing, often attributed to cultural differences between surgical and palliative care fields, results in missed opportunities for early symptom control and comprehensive family support. Studies reveal that some surgeons delay PPC consultations out of concern that introducing palliative care too early might discourage families or imply that treatment has been exhausted.


Communication between PPC teams and pediatric surgeons is crucial for achieving optimal care outcomes. Surveys highlight that PPC professionals believe these discussions should occur much earlier in the disease process to maximize the benefits of palliative interventions. In many cases, families report that they wish they had been introduced to palliative care earlier, as it would have helped them manage their child's symptoms more effectively and provided emotional support during difficult times. For pediatric surgeons, initiating conversations about PPC can be challenging, particularly if they feel it conflicts with families' expectations for life-saving measures. Consequently, PPC training for surgeons has emerged as a key area for improving collaboration and communication. In response, residency programs and continuing medical education increasingly include training modules focused on PPC to enhance understanding and acceptance of palliative practices among surgeons.


Research further indicates the need for multidisciplinary approaches that include PPC in pediatric surgical care. Integrating PPC professionals as core team members in surgical planning can foster an environment where families feel supported in their decisions, whether they pursue aggressive interventions or prioritize comfort and quality of life. Collaborative care allows each team member to contribute their specialized expertise. PPC professionals offer insight into symptom management and psychological support, while surgeons provide technical assessments of what surgery might accomplish. Through this collaboration, PPC ensures that surgical interventions align with family goals and the child's best interests, even when curative options are no longer viable.


Looking forward, the scope of PPC in pediatric surgery continues to expand. Conditions such as neurodegenerative disorders, complex congenital malformations, and progressive illnesses are increasingly managed with an interdisciplinary approach that includes PPC from early stages. Pediatric surgeons are recognizing the value of palliative interventions, not only for terminally ill patients but also for children with chronic, debilitating conditions. Additionally, as more pediatric surgical specialists receive PPC training, there is a greater opportunity for meaningful collaborations that can enhance the quality of life for children undergoing intensive surgical care. The evidence supports that PPC integration leads to more compassionate, well-rounded care that respects both the child's dignity and the families experience.


In conclusion, the integration of palliative care into pediatric surgery represents a transformative shift towards a patient-centered model that prioritizes quality of life alongside medical treatment. By focusing on early symptom management, ethical decision-making, and supportive family care, PPC complements surgical interventions, ensuring that young patients with complex medical needs receive holistic, compassionate care. As PPC becomes more embedded in pediatric surgery practices, it promises to further bridge the gap between life-saving surgery and quality of life, offering families comfort, guidance, and hope in the face of challenging medical journeys.


References:
1- Shelton J, Jackson GP: Palliative care and pediatric surgery. Surg Clin North Am. 91(2):419-28, 2011
2- Inserra A, Narciso A, Paolantonio G, Messina R, Crocoli A: Palliative care and pediatric surgical oncology. Semin Pediatr Surg. 25(5):323-332, 2016
3- Spruit JL, Prince-Paul M. Palliative care services in pediatric oncology: Ann Palliat Med. 8(Suppl 1), 2019
4- Ott KC, Vente TM, Lautz TB, Waldman ED: Pediatric palliative care and surgery. Ann Palliat Med. 11(2):918-926, 2022
5- De Bie FR, Tate T, Antiel RM: Maternal-fetal surgery as part of pediatric palliative care. Semin Fetal Neonatal Med. 28(3):101440, 2023
6- Ellis D, Mazzola E, Wolfe J, Kelleher C: Comparing Pediatric Surgeons' and Palliative Care Pediatricians' Palliative Care Practices and Perspectives in Pediatric Surgical Patients. J Pediatr Surg. 59(1):37-44, 2024
7- Li O, Lee R, Boss RD, Wang MH: Palliative Care for Pediatric Urology. J Pain Symptom Manage. 68(1), 2024

NPO Guidelines in Pediatric Surgery

The practice of "nil per os" (NPO), or nothing by mouth, for children undergoing surgery has been a subject of intense scrutiny and evolution over the years. Various studies and guidelines highlight the balance between minimizing the risk of pulmonary aspiration during anesthesia and reducing the adverse effects of prolonged fasting on children?s metabolic and psychological well-being.


Historically, the NPO protocol has been rigid, often enforcing a midnight fast for all patients scheduled for surgery. This practice, aimed at preventing aspiration, has faced criticism for its negative impact on children. Prolonged fasting can lead to dehydration, hypoglycemia, and behavioral issues like irritability and anxiety. Studies show that the current international guidelines allow more flexibility, advocating for fasting durations of 2 hours for clear liquids, 4 hours for breast milk, and 6 hours for solids. However, these guidelines are frequently exceeded in practice due to scheduling inefficiencies and miscommunication.


One of the major challenges identified is parental compliance with fasting instructions. Research indicates that less than 10% of parents fully adhere to the prescribed NPO times, with most either under-fasting or over-fasting their children. The reasons for non-compliance include inadequate understanding of instructions, fear of surgical delays or cancellations, and the difficulty of denying food or drinks to a distressed child. Miscommunication between healthcare providers and parents further exacerbates the issue, as conflicting or unclear instructions lead to confusion. Studies recommend clearer communication strategies, such as providing separate written instructions for solids and liquids and ensuring consistency in messaging.


The metabolic implications of prolonged fasting are particularly concerning for pediatric patients, as their smaller glycogen reserves make them more susceptible to hypoglycemia. This metabolic stress not only affects their energy levels but also impairs their ability to cope with the stress of surgery, potentially delaying recovery. Research highlights the benefits of shorter fasting periods, noting that children allowed to consume clear liquids up to 2 hours before surgery exhibit better hydration, reduced irritability, and lower gastric pH levels without increasing the risk of aspiration.


Recent quality improvement initiatives have shown promise in addressing the shortcomings of current NPO practices. For instance, allowing children to drink clear liquids up to 1 hour before surgery has been shown to significantly reduce fasting times and improve overall patient comfort. Such liberalized fasting guidelines align with modern evidence suggesting that aspiration risk does not increase with shorter fasting durations. These changes have been endorsed by leading anesthesia societies in Europe and Canada, emphasizing the importance of minimizing disruption to normal physiological states preoperatively.


Despite these advancements, the implementation of more liberal NPO guidelines faces resistance. Anesthesiologists and surgeons often express concerns about flexibility in scheduling and the potential for last-minute changes in surgery times. This conservatism results in a default return to the midnight fasting rule in many institutions, particularly for inpatients or cases with higher perceived aspiration risks. To counter this, some hospitals have developed task forces to standardize and enforce updated guidelines, incorporating strategies like using arrival times instead of surgery times to calculate fasting periods and encouraging the administration of clear liquids closer to the surgery.


Compliance with updated NPO guidelines also varies significantly across healthcare settings. Data show that prolonged fasting is more common in settings with less robust quality improvement frameworks or where the operational culture is resistant to change. For example, effective fasting times for clear liquids can extend beyond seven hours, even when shorter durations are recommended. Educational initiatives targeting healthcare providers and parents are critical in bridging this gap, ensuring both groups understand the rationale and safety of revised fasting protocols.


The adverse effects of prolonged fasting extend beyond the physiological to the psychological, with many children experiencing heightened anxiety and behavioral challenges due to hunger and thirst. These factors contribute to a less favorable surgical experience, both for the patient and their family. Addressing these issues requires a multifaceted approach, including better preoperative education, consistent adherence to evidence-based guidelines, and ongoing monitoring and adjustment of fasting practices based on patient outcomes.


In conclusion, while significant strides have been made in revising and liberalizing NPO guidelines for children, the practical application of these recommendations remains inconsistent. Barriers such as communication lapses, entrenched practices, and operational constraints continue to impede progress. Moving forward, greater emphasis on quality improvement initiatives, clearer communication strategies, and more flexible approaches to fasting durations are essential to enhance compliance and improve the overall surgical experience for pediatric patients. These changes must be supported by ongoing research and a willingness among healthcare providers to adopt evidence-based practices, ensuring that children receive care that is both safe and compassionate.


References:
1- Brunet-Wood K, Simons M, Evasiuk A, Mazurak V, Dicken B, Ridley D, Larsen B: Surgical fasting guidelines in children: Are we putting them into practice? J Pediatr Surg. 51(8):1298-302, 2016
2- Beazley B, Bulka CM, Landsman IS, Ehrenfeld JM: Demographic Predictors of NPO Violations in Elective Pediatric Surgery. J Perianesth Nurs. 31(1):36-40, 2016
3- Kafrouni H, Ojaimi RE: Preoperative Fasting Guidelines in Children: Should They Be Revised? Case Rep Anesthesiol. 2018:8278603, 2018
4- Friedrich S, Meybohm P, Kranke P: Nulla Per Os (NPO) guidelines: time to revisit? Curr Opin Anaesthesiol. 33(6):740-745, 2020
5- Singla K, Bala I, Jain D, Bharti N, Samujh R: Parents' perception and factors affecting compliance with preoperative fasting instructions in children undergoing day care surgery: A prospective observational study. Indian J Anaesth. 64(3):210-215, 2020
6- Schmidt AR, Fehr J, Man J, D'Souza G, Wang E, Claure R, Mendoza J: Pre-operative fasting times for clear liquids at a tertiary children's hospital; what can be improved? Anesth Pain Med (Seoul). 16(3):266-272, 2021

TLR4 in Necrotizing Enterocolitis

Toll-like receptor 4 (TLR4) plays a pivotal role in the pathogenesis of necrotizing enterocolitis (NEC), a life-threatening gastrointestinal disease in premature infants. NEC is associated with a high mortality rate and severe long-term complications, including short-bowel syndrome and neurodevelopmental impairment. The role of TLR4 in NEC pathogenesis has been extensively studied, revealing its involvement in immune activation, epithelial injury, and intestinal ischemia. The following review synthesizes findings from six key studies to provide a comprehensive understanding of the molecular mechanisms underlying TLR4-mediated NEC and emerging therapeutic approaches.


NEC is primarily a disease of premature infants, occurring in up to 10% of those born with a birth weight under 1500 grams. Its pathogenesis is multifactorial, involving intestinal immaturity, dysbiotic microbiota, and exaggerated immune responses. TLR4, an innate immune receptor, has been identified as a central mediator of these processes. It recognizes lipopolysaccharides (LPS) on Gram-negative bacteria, triggering proinflammatory signaling cascades that disrupt the intestinal epithelial barrier. In premature infants, TLR4 expression is significantly elevated compared to full-term counterparts, contributing to increased susceptibility to NEC.


The role of TLR4 extends beyond its recognition of microbial pathogens. Research has shown that TLR4 activation leads to apoptosis and necroptosis of intestinal epithelial cells. These processes compromise the integrity of the gut barrier, facilitating bacterial translocation into the bloodstream and triggering systemic inflammation. TLR4-mediated necroptosis, specifically, has been highlighted as a distinct mechanism contributing to the rapid and severe tissue damage characteristic of NEC. Studies in TLR4-knockout animal models have confirmed the critical role of TLR4 in driving necroptosis, with these models demonstrating reduced epithelial injury and inflammatory responses.


Another critical mechanism by which TLR4 contributes to NEC is through its effects on the mesenteric vasculature. Activation of TLR4 on endothelial cells induces vasoconstriction and intestinal ischemia, exacerbating tissue injury. In animal models, the inhibition of TLR4 signaling has been shown to restore mesenteric perfusion and mitigate ischemic damage. This highlights the interconnected nature of inflammatory and ischemic processes in NEC pathogenesis.


The interaction between TLR4 and the enteric nervous system has also been implicated in NEC. Research has demonstrated that TLR4 activation leads to the loss of enteric glial cells, which are essential for maintaining intestinal motility and barrier integrity. The depletion of these glial cells disrupts the anti-inflammatory feedback mechanisms of the gut, further amplifying TLR4-mediated damage. The restoration of enteric glial cell function has been proposed as a therapeutic strategy, with promising results observed in preclinical models.


One of the most consistent clinical observations in NEC is the protective effect of human breast milk. This protection is attributed to specific components of breast milk, such as human milk oligosaccharides (HMOs), which have been shown to inhibit TLR4 signaling. Studies focusing on HMOs, including 2?-fucosyllactose and 6?-sialyllactose, have demonstrated their ability to reduce TLR4-mediated inflammation and apoptosis in experimental NEC models. These oligosaccharides bind directly to TLR4, preventing its activation by LPS and other microbial ligands. Formula-fed infants, lacking these protective factors, exhibit higher rates of NEC, further underscoring the importance of breast milk in prevention strategies.


The role of the microbiome in NEC is closely linked to TLR4 activity. Premature infants with NEC exhibit a dysbiotic microbiota characterized by reduced bacterial diversity and an overrepresentation of pathogenic strains. This dysbiosis increases the availability of microbial ligands that activate TLR4, perpetuating the inflammatory cycle. Probiotic administration has emerged as a potential intervention, with several studies demonstrating that probiotics can restore microbial balance, reduce TLR4 activation, and protect against NEC. The exact mechanisms by which probiotics exert these effects are under investigation, but they likely involve competitive inhibition of pathogenic bacteria and modulation of host immune responses.


Therapeutic approaches targeting TLR4 directly have shown promise in preclinical studies. Small-molecule inhibitors of TLR4, such as specific antagonists that block LPS binding, have been effective in reducing NEC severity in animal models. These inhibitors work by attenuating the proinflammatory signaling cascades initiated by TLR4 activation, thereby preserving the integrity of the intestinal barrier. Additionally, strategies aimed at enhancing the expression of protective molecules, such as brain-derived neurotrophic factor (BDNF), have been explored. BDNF is reduced in NEC and plays a critical role in modulating TLR4 activity and maintaining intestinal homeostasis.


Another innovative approach involves the use of anti-necroptotic agents. Necrostatin-1, a specific inhibitor of necroptosis, has been shown to reduce intestinal injury and inflammation in NEC models. This therapy targets the downstream effects of TLR4 activation, preventing the catastrophic cell death and barrier dysfunction associated with necroptosis. Combined approaches that integrate TLR4 inhibition with necroptosis suppression may offer synergistic benefits.


Despite these advances, translating preclinical findings into clinical practice remains challenging. The heterogeneity of NEC, its unpredictable onset, and the limitations of current diagnostic tools complicate the development and implementation of targeted therapies. The Bell staging system, commonly used to classify NEC severity, has limitations in its ability to distinguish NEC from other neonatal gastrointestinal conditions. Improved diagnostic criteria and biomarkers are needed to identify at-risk infants and tailor interventions effectively.


Future research should focus on elucidating the complex interplay between TLR4 signaling, the microbiome, and host factors in NEC. Advances in genomic and proteomic technologies offer opportunities to identify novel targets and refine therapeutic strategies. Additionally, the integration of precision medicine approaches, including the use of individualized probiotic formulations and personalized nutrition plans, holds promise for improving outcomes in NEC.

In conclusion, TLR4 is a central player in the pathogenesis of NEC, orchestrating a cascade of inflammatory, ischemic, and apoptotic processes that culminate in severe intestinal injury. Insights into the molecular mechanisms of TLR4-mediated NEC have paved the way for innovative therapeutic strategies, ranging from breast milk-derived interventions to targeted molecular inhibitors. While significant challenges remain, continued research into TLR4 and its role in NEC holds the potential to transform the prevention and treatment of this devastating disease, ultimately improving survival and quality of life for premature infants.


References:
1- Hackam DJ, Sodhi CP: Toll-Like Receptor-Mediated Intestinal Inflammatory Imbalance in the Pathogenesis of Necrotizing Enterocolitis. Cell Mol Gastroenterol Hepatol. 6(2):229-238.e1, 2018
2-  Mihi B, Good M: Impact of Toll-Like Receptor 4 Signaling in Necrotizing Enterocolitis: The State of the Science. Clin Perinatol. 46(1):145-157, 2019
3- Sodhi CP, Wipf P, Yamaguchi Y, Fulton WB, Kovler M, Ni¤o DF, Zhou Q, Banfield E, Werts AD, Ladd MR, Buck RH, Goehring KC, Prindle T Jr, Wang S, Jia H, Lu P, Hackam DJ:. The human milk oligosaccharides 2'-fucosyllactose and 6'-sialyllactose protect against the development of necrotizing enterocolitis by inhibiting toll-like receptor 4 signaling. Pediatr Res.89(1):91-101, 2021
4- Kovler ML, Gonzalez Salazar AJ, Fulton WB, Lu P, Yamaguchi Y, Zhou Q, Sampah M, Ishiyama A, Prindle T Jr, Wang S, Jia H, Wipf P, Sodhi CP, Hackam DJ: Toll-like receptor 4-mediated enteric glia loss is critical for the development of necrotizing enterocolitis. Sci Transl Med. 13(612):eabg3459, 2021
5- Liu T, Zong H, Chen X, Li S, Liu Z, Cui X, Jia G, Shi Y: Toll-like receptor 4-mediated necroptosis in the development of necrotizing enterocolitis. Pediatr Res. 91(1):73-82, 2022
6- Duess JW, Sampah ME, Lopez CM, Tsuboi K, Scheese DJ, Sodhi CP, Hackam DJ: Necrotizing enterocolitis, gut microbes, and sepsis. Gut Microbes. 15(1):2221470, 2023

PSU Volume 64 No 02 FEBRUARY 2025

Uretero-Inguinal Hernia

Uretero-inguinal hernia (UIH) is an exceedingly rare condition, characterized by the displacement of the ureter into the inguinal canal. This phenomenon can be congenital or acquired and is often associated with complex anatomical anomalies or predisposing factors. It poses diagnostic and therapeutic challenges due to its unusual presentation and the potential for severe complications if not identified and managed appropriately.


UIH has two primary classifications: paraperitoneal and extraperitoneal. Paraperitoneal UIH, which constitutes approximately 80% of cases, involves the ureter adhering to a hernial sac and being pulled into the inguinal canal. This type is often linked to sliding hernias and may involve other abdominal viscera. In contrast, extraperitoneal UIH, accounting for the remaining 20%, occurs without a hernial sac and is typically associated with congenital anomalies of the ureteral and renal systems. This variety is believed to result from abnormal embryological development, such as late separation of the Wolffian duct or adherence of the ureter to genitoinguinal structures.


UIH predominantly affects males, possibly due to the developmental descent of the Wolffian duct structures into the scrotum, creating a pathway for ureteral involvement. In adults, risk factors include advanced age, obesity, renal transplantation, and collagen disorders. In children, the condition is exceptionally rare, with only a limited number of documented cases.


Clinical manifestations of UIH are varied and depend on the extent of ureteral involvement and the presence of secondary complications. Patients may present with symptoms ranging from an asymptomatic inguinal mass to signs of obstructive uropathy, such as flank pain, hematuria, or hydronephrosis. In many cases, UIH is discovered incidentally during surgical exploration for inguinal hernia repair. Imaging modalities like ultrasound, computed tomography (CT), and voiding cystourethrography (VCUG) play critical roles in preoperative diagnosis, helping identify ureteral involvement and associated urinary tract anomalies.


Management of UIH requires careful surgical intervention to prevent iatrogenic injuries. The approach varies depending on the type and severity of the hernia, as well as the patient?s overall condition. For paraperitoneal UIH, high ligation of the hernial sac and repositioning of the ureter are common strategies. For extraperitoneal cases, interventions may include ureteral reimplantation or ureteroneocystostomy, especially in the presence of significant obstruction or stricture.


In pediatric cases, the rarity of UIH necessitates heightened clinical awareness, particularly in the presence of congenital urological anomalies. Early recognition and intervention are essential to avoid complications like ureteral injury or progressive renal impairment. Long-term follow-up with renal function tests and imaging is crucial to monitor outcomes and prevent recurrence.


The literature highlights the importance of individualized care and the role of multidisciplinary teams, including pediatric surgeons, urologists, and radiologists, in managing this complex condition. Advances in laparoscopic techniques have improved visualization and allowed for more precise interventions, reducing morbidity, and enhancing recovery.


UIH represents a fascinating interplay between congenital and acquired factors, with implications for both surgical practice and urological management. Continued documentation of cases and research into the underlying mechanisms will be essential to refine diagnostic and therapeutic strategies for this rare entity.


References:
1- Handu AT, Garge S, Peters NJ, Kanojia RP, Rao KL: Undiagnosed ureteroinguinal hernia with solitary kidney in a child with ureteric injury during herniotomy. J Pediatr Surg. 47(4):799-802, 2012
2- Lakshmi Narayanan P, C D N, Sekar V, Vadyala AR: Laparoscopic approach to ureteroinguinal hernia. Int J Surg Case Rep. 77:161-164, 2020
3- Turner A, Subramanian P. Ureteroinguinal Hernia: A Rare General Surgery Phenomenon. Cureus. 13(12):e20586, 2021
4- Cianci MC, Tocchioni F, Mantovani A, Ghionzoli M, Morini F: Unexpected Pediatric Uretero-Inguinal Hernia: Case-Report and Literature Review. Urology. 2023 Jun;176:178-182, 2023
5- Delgado-Miguel C, Mu¤oz-Serrano AJ, Aguado P, Fuentes E, D¡ez R: Ureteroinguinal Herniation with Consecutive Ureteral Stricture in a 2-Month-Old Infant: Case Report. European J Pediatr Surg Rep. 12(1):e16-e19, 2024
6-Ger‡el G: A surprise during hernia surgery: inguinoscrotal megaureter. Turk J Pediatr. 66(3):378-382, 2024

Antithrombotic Therapy

Antithrombotic therapy for children is a rapidly evolving area of medical research and practice due to the increasing recognition and diagnosis of thromboembolic events (TEs) in pediatric populations. Unlike adults, children experience TEs primarily as a consequence of severe illness or medical interventions, such as central venous catheterization. This distinct etiology necessitates tailored approaches to diagnosis, treatment, and prevention.


Pediatric TEs differ significantly from adult cases in terms of epidemiology, pathophysiology, and therapeutic implications. While the incidence of VTE in the general pediatric population remains low (0.07 to 0.14 per 10,000 children), hospitalized children face a much higher risk up to 1000-fold greaterdue to the widespread use of central venous access devices (CVADs) and other invasive procedures. Neonates and adolescents constitute the most vulnerable groups, reflecting distinct physiological and pathophysiological factors such as immature coagulation systems and pubertal hormonal changes.


The pediatric coagulation system undergoes significant maturation during the first year of life, which alters the pharmacodynamics and pharmacokinetics of anticoagulant medications. For instance, younger children often require higher weight-based doses of anticoagulants, despite having lower levels of coagulation proteins. These differences pose unique challenges in drug selection, dosing, and monitoring.


Historically, antithrombotic therapy in children has relied on unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), and vitamin K antagonists (VKAs). However, recent advances have introduced direct oral anticoagulants (DOACs) as a promising alternative due to their consistent pharmacokinetics, ease of administration, and reduced monitoring requirements. Clinical trials have demonstrated that DOACs, such as rivaroxaban and dabigatran, are as effective as standard anticoagulants while offering improved safety profiles.


The American Society of Hematology (ASH) 2018 guidelines emphasize the use of anticoagulation in symptomatic VTE and stress the importance of individualized therapy based on the patient's clinical status and risk factors. For asymptomatic cases, the decision to treat remains contentious, reflecting the low certainty of evidence regarding the balance between risks and benefits. The recommendations also underline the need for multidisciplinary care involving pediatric hematologists to optimize treatment outcomes.


Updated guidance from the International Society on Thrombosis and Haemostasis (ISTH) has refined outcome definitions for pediatric VTE clinical trials, introducing parameters like patient-important bleeding to standardize safety assessments. These developments aim to enhance the comparability and applicability of trial results.


Despite significant progress, challenges remain. Many recommendations for pediatric antithrombotic therapy are extrapolated from adult studies due to the limited number of pediatric-specific trials. This reliance underscores the need for robust, age-appropriate research to address gaps in knowledge, particularly regarding long-term outcomes and the management of chronic conditions such as post-thrombotic syndrome.


Meta-analyses and network comparisons have further clarified the efficacy and safety of various anticoagulants. For example, DOACs have shown non-inferiority to traditional agents in preventing recurrent TEs, with lower risks of major bleeding. However, concerns persist about their use in specific pediatric subgroups, such as neonates and critically ill children, highlighting the importance of cautious implementation based on individual risk profiles.


Prophylactic anticoagulation remains a debated topic in pediatric care. Although standard in adult practice, its routine use in children is not widely endorsed due to the scarcity of high-quality evidence supporting its benefits. Studies investigating the role of prophylaxis in high-risk settings, such as CVAD-related thrombosis, have yielded mixed results, further complicating clinical decision-making.


Emerging research continues to expand the therapeutic arsenal for pediatric TEs. The advent of age-specific formulations of DOACs, coupled with advances in imaging and biomarker technologies, holds promise for improving diagnostic precision and treatment efficacy. Moreover, ongoing trials are expected to address critical questions about optimal dosing, duration of therapy, and long-term safety.


In conclusion, antithrombotic therapy in children has evolved significantly, driven by a growing understanding of pediatric hemostasis and advances in pharmacology. While traditional anticoagulants remain the cornerstone of treatment, DOACs represent a paradigm shift in managing pediatric TEs. Nevertheless, the field requires continued investment in research and collaboration to refine therapeutic strategies and ensure the best outcomes for young patients.


References:
1- Monagle P, Chan AKC, Goldenberg NA, Ichord RN, Journeycake JM, Nowak-GŒttl U, Vesely SK:  Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 141(2 Suppl):e737S-e801S, 2012
2- Young G. Anticoagulation Therapies in Children: Pediatr Clin North Am. 64(6):1257-1269, 2017
3- Monagle P, Cuello CA, Augustine C, Bonduel M, Brand?o LR, Capman T, Chan AKC, Hanson S, Male C, Meerpohl J, et al: American Society of Hematology 2018 Guidelines for management of venous thromboembolism: treatment of pediatric venous thromboembolism. Blood Adv. 2(22):3292-3316, 2018
4- Whitworth H, Amankwah EK, Betensky M, Castellucci LA, Cuker A, Goldenberg NA, Male C, Rinzler E, Zia A, Raffini L: Updated guidance for efficacy and safety outcomes for clinical trials in venous thromboembolism in children: Communication from the ISTH SSC Subcommittee on Pediatric and Neonatal Thrombosis and Hemostasis. J Thromb Haemost. 21(6):1666-1673, 2023
5- Gao H, Chen M, Huang Y, Liu H, Lin Y, Chen M: Efficacy and safety of antithrombotic therapy for preventing and treating pediatric thromboembolic disease: A systematic review. Sci Rep. 14(1):13378, 2024
6- Manco-Johnson MJ, Annam A, Schardt : Anticoagulation in Pediatric Patients. Tech Vasc Interv Radiol. 27(2):100958, 2024

Adamkiewicz Artery in Pediatric Posterior Thoracic Tumors

Posterior thoracic tumors in pediatric patients, particularly those of neurogenic origin such as neuroblastomas and ganglioneuromas, pose unique surgical challenges due to their proximity to the Artery of Adamkiewicz (AKA). This artery, the primary blood supply to the anterior spinal cord, is often located between the T8 and L1 vertebral levels and exhibits significant anatomical variability. Inadvertent injury to the AKA during tumor resection can lead to catastrophic outcomes, including anterior spinal cord ischemia, paraparesis, or paraplegia. Consequently, accurate preoperative identification of the AKA is critical to surgical planning and patient safety.


Recent advancements in imaging techniques, particularly spinal angiography (SA) and Magnetic Resonance Angiography (MRA), have revolutionized preoperative evaluation for pediatric patients with posterior thoracic tumors. These modalities allow detailed mapping of the spinal vasculature, enabling surgeons to plan resections that minimize the risk of vascular injury. Studies have demonstrated that incorporating these imaging techniques into preoperative protocols not only improves surgical outcomes but also reduces the incidence of neurologic complications.


One study involving 36 pediatric patients evaluated the utility of preoperative spinal angiography. Among these patients, SA identified the AKA in all cases, demonstrating its reliability in mapping vascular anatomy. In four cases where the AKA was in close proximity to the tumor, surgical plans were modified, with three patients undergoing non-surgical management, such as radiation therapy, to mitigate risk. Importantly, no complications arose from the SA procedure itself, highlighting its safety and efficacy as a preoperative tool.


Another key finding from recent research is the significant reduction in neurologic complications when SA is employed. A retrospective analysis comparing outcomes before and after the routine use of SA in pediatric posterior thoracic tumor resections revealed a marked decrease in the incidence of postoperative spinal ischemia. Prior to implementing routine SA, one patient in the study cohort developed paraplegia following resection. Post-SA implementation, no such complications were observed, underscoring the role of detailed preoperative vascular mapping in enhancing patient safety.


In addition to spinal angiography, Magnetic Resonance Angiography (MRA) has shown promise as a non-invasive alternative for visualizing the AKA. A case report highlighted the successful use of MRA in a 14-month-old child with a thoracic neuroblastoma. The imaging identified the precise location of the AKA, allowing the surgical team to avoid critical vascular structures during resection. MRA's non-invasive nature and ability to provide high-resolution images make it particularly suitable for pediatric patients, where minimizing procedural risks is paramount.


Despite these advancements, challenges remain in achieving consistent and accurate preoperative identification of the AKA. The artery's variability in origin, pathway, and laterality necessitates a tailored approach for each patient. Moreover, the choice of imaging modality—whether SA, MRA, or a combination—often depends on institutional resources and expertise. While spinal angiography remains the gold standard for AKA visualization, its invasive nature, and associated risks, though minimal, must be carefully weighed against the benefits in each case.


The integration of imaging findings into surgical decision-making has profound implications for treatment strategies. In cases where the AKA is identified in close proximity to the tumor, surgeons may opt for partial resections, alternative surgical approaches, or adjunctive therapies such as radiation. This tailored approach not only preserves spinal cord function but also improves overall outcomes by reducing the likelihood of tumor recurrence or residual disease.


Studies also emphasize the importance of interdisciplinary collaboration in managing these complex cases. The involvement of pediatric surgeons, interventional radiologists, and neuro-oncologists ensures a comprehensive evaluation of risks and benefits, facilitating informed decision-making. Multidisciplinary tumor boards play a pivotal role in this process, integrating imaging findings with clinical and pathological data to devise individualized treatment plans.


Further research is needed to refine imaging techniques and establish standardized protocols for preoperative evaluation of the AKA. Emerging technologies, such as advanced MRI sequences and 3D vascular mapping, hold promise for enhancing the accuracy and accessibility of preoperative imaging. Additionally, longitudinal studies assessing long-term outcomes in patients undergoing surgery with preoperative AKA identification will provide valuable insights into the efficacy of these strategies.


In conclusion, the preoperative identification of the Adamkiewicz Artery is a critical component of surgical planning for pediatric posterior thoracic tumors. Techniques such as spinal angiography and Magnetic Resonance Angiography enable precise vascular mapping, significantly reducing the risk of spinal ischemia and associated neurologic complications. By incorporating these modalities into preoperative protocols and fostering interdisciplinary collaboration, healthcare teams can optimize surgical outcomes and improve the quality of life for pediatric patients with these challenging tumors. Continued advancements in imaging technology and research will further enhance the safety and efficacy of these interventions, paving the way for improved standards of care in pediatric oncology.


References:
1- Boglino C, Martins AG, Ciprandi G, Sousinha M, Inserra A: Spinal cord vascular injuries following surgery of advanced thoracic neuroblastoma: an unusual catastrophic complication. Med Pediatr Oncol. 32(5):349-52, 1999
2- Nordin AB, Fallon SC, Jea A, Kim ES: The use of spinal angiography in the management of posterior mediastinal tumors: case series and review of the literature. J Pediatr Surg. 48(9):1871-7, 2013
3- Schmidt A, Hempel JM, Ellerkamp V, Warmann SW, Ernemann U, Fuchs J: The Relevance of Preoperative Identification of the Adamkiewicz Artery in Posterior Mediastinal Pediatric Tumors. Ann Surg Oncol. 29(1):493-499, 2022
4- Clark RA, Jacobson JC, Murphy JT: Preoperative spinal angiography decreases risk of spinal ischemia in pediatric posterior thoracic tumor resection. Pediatr Surg Int. 38(10):1427-1434, 2022
5- Almeida AI, Vasconcelos-Castro S, Sampaio L: Successful technical note-Identification of the Adamkievicz artery with 1.5 Tesla MR angiography in a 14-month-old child. Radiol Case Rep. 18(1):188-191, 2022
5- Zarfati A, Guérin F, Dioguardi Burgio M, Fuchs J, Sarnacki S, Losty PD, Pio L: Preoperative Identification of Adamkiewicz Artery in Pediatric Posterior Thoracic Tumors: Fact or Fiction? A Systematic Review from the International Society of Pediatric Surgical Oncology (IPSO). J Pediatr Surg. 59(12):161985, 2024


PSU Volume 64 No 03 MARCH 2025

NAVA

Neurally-Adjusted Ventilatory Assist (NAVA) is a novel mode of mechanical ventilation that synchronizes ventilator support with the patient?s respiratory efforts by monitoring the electrical activity of the diaphragm (EAdi). Introduced over two decades ago, NAVA has garnered attention for its potential to improve patient-ventilator interaction, reduce ventilator-induced injuries, and enhance clinical outcomes in various patient populations. This review delves into the physiological principles, clinical applications, comparative effectiveness, and challenges associated with NAVA.


Unlike conventional ventilation modes that rely on pneumatic signals such as flow or pressure for triggering, NAVA uses EAdi to initiate and terminate ventilator assistance. The diaphragm's electrical activity, detected via a nasogastric tube equipped with specialized electrodes, reflects the central respiratory drive. This signal provides a precise and dynamic measure of respiratory effort, allowing ventilatory support to be proportional to the patient?s needs throughout each breath. By ensuring that the ventilator is in tune with the patient?s neural respiratory cycle, NAVA minimizes asynchrony, a common issue in traditional ventilation modes. Studies have consistently demonstrated the ability of NAVA to optimize ventilator-patient interaction, particularly in patients with complex respiratory mechanics, such as those with low lung compliance or high airway resistance.


One of the key advantages of NAVA is its ability to enhance synchrony, even in challenging conditions like acute respiratory distress syndrome (ARDS) or chronic obstructive pulmonary disease (COPD). Conventional modes such as pressure support ventilation (PSV) often struggle to maintain synchrony, leading to asynchrony indices as high as 30% in some populations. In contrast, studies comparing NAVA and PSV show significantly lower asynchrony indices in NAVA, underscoring its superiority in ensuring coordination between neural and mechanical respiratory cycles. This improved synchrony has far-reaching implications, including reduced work of breathing, better gas exchange, and enhanced patient comfort.


NAVA also plays a crucial role in preserving diaphragm function. In traditional ventilation, excessive assistance can suppress respiratory drive, leading to ventilator-induced diaphragm dysfunction (VIDD). By delivering proportional support, NAVA prevents over-assistance and maintains adequate diaphragm activity, reducing the risk of atrophy. This aspect of diaphragm-protective ventilation is particularly important in patients requiring prolonged mechanical support.


Additionally, NAVA contributes to lung protection by minimizing ventilator-induced lung injury (VILI). Conventional modes often deliver fixed tidal volumes or pressures, which can result in barotrauma or volutrauma in vulnerable patients. With NAVA, the ventilator dynamically adjusts pressure in response to the patient's effort, reducing the likelihood of excessive lung stress or strain. Studies in animal models and human subjects confirm that NAVA helps distribute ventilation more evenly across lung regions, thereby mitigating the risk of localized overdistension.


The versatility of NAVA makes it applicable to diverse patient populations, including adults with acute respiratory failure, pediatric patients, and neonates. In adult intensive care units (ICUs), NAVA has been shown to improve clinical outcomes such as duration of ventilation and patient comfort. A narrative review highlighted that NAVA's proportional support not only ensures adequate gas exchange but also reduces the risk of apnea and asynchrony during noninvasive ventilation (NIV). These benefits are particularly pronounced in patients with ARDS or COPD exacerbations, where traditional modes often fall short.


In pediatric intensive care units (PICUs), NAVA is increasingly being used as a weaning mode for invasively ventilated children. Systematic reviews indicate that NAVA reduces the length of PICU stays and sedation requirements compared to traditional modes. For example, a cohort study involving children recovering from cardiac surgery reported higher extubation success rates and shorter ventilation durations with NAVA. Despite these promising findings, the evidence base remains limited, necessitating further research to establish standardized protocols and optimize outcomes.


The use of NAVA in neonates, particularly preterm infants, presents unique challenges and opportunities. Neonates often require prolonged respiratory support due to immature lungs and respiratory control mechanisms. Traditional ventilation modes frequently fail to achieve synchrony in this population due to their rapid respiratory rates and small tidal volumes. NAVA, by directly responding to neural signals, offers a solution to these issues. Studies have demonstrated that NAVA reduces bronchopulmonary dysplasia (BPD) and improves extubation success rates in preterm infants. However, technical difficulties in acquiring reliable EAdi signals and the prevalence of apnea in this population remain significant barriers to widespread adoption.


When compared to conventional ventilation modes, NAVA consistently outperforms in terms of synchrony, patient comfort, and physiological outcomes. Meta-analyses of studies comparing NAVA and PSV during noninvasive ventilation reveal significantly lower asynchrony indices and fewer ineffective efforts in the NAVA group. However, the data on clinical outcomes such as mortality and length of ICU stay are less conclusive. For instance, while some studies report shorter ventilation durations and reduced sedation requirements with NAVA, others note no significant differences in mortality rates or overall clinical outcomes. These discrepancies highlight the need for larger, multicenter randomized controlled trials (RCTs) to validate the observed benefits and explore their impact on long-term outcomes.


Despite its advantages, NAVA is not without limitations. One of the primary challenges is the reliance on a specialized nasogastric tube for EAdi signal acquisition. This requirement can lead to discomfort and may not be feasible in all patients. Additionally, the need for trained personnel to manage NAVA settings and interpret EAdi signals has hindered its widespread adoption. Cost considerations also play a role, as NAVA-specific equipment and training represent a significant investment for healthcare facilities.


In neonates, the frequent occurrence of apnea and insufficient triggering of EAdi signals pose specific challenges. These issues necessitate careful titration of NAVA settings and ongoing monitoring to ensure effective ventilation. Furthermore, the limited availability of robust clinical data in this population underscores the need for targeted research.


The future of NAVA lies in expanding its clinical applications and addressing existing limitations. Technological advancements aimed at improving EAdi signal acquisition and patient comfort could enhance the feasibility of NAVA in a broader range of patients. Research efforts should focus on conducting large-scale RCTs to establish evidence-based guidelines for NAVA use across different populations. Additionally, exploring the integration of NAVA with other innovative ventilation strategies could pave the way for personalized respiratory support tailored to individual patient needs.


In conclusion, NAVA represents a significant advancement in mechanical ventilation, offering improved synchrony, diaphragm preservation, and lung protection compared to conventional modes. While challenges remain, the growing body of evidence supporting its physiological and clinical benefits makes NAVA a promising tool in the management of respiratory failure. Continued research and innovation are essential to fully realize its potential and optimize outcomes for patients across the age spectrum.


References:
1- Navalesi P, Longhini F: Neurally adjusted ventilatory assist. Curr Opin Crit Care. 21(1):58-64, 2015
2- Sugunan P, Hosheh O, Garcia Cusco M, Mildner R: Neurally-Adjusted Ventilatory Assist (NAVA) versus Pneumatically Synchronized Ventilation Modes in Children Admitted to PICU. J Clin Med. 10(15):3393, 2021
3- Umbrello M, Antonucci E, Muttini S: Neurally Adjusted Ventilatory Assist in Acute Respiratory Failure-A Narrative Review. J Clin Med. 11(7):1863, 2022
4- Weiyun T, Linli S, Liuzhao C: Neurally-Adjusted Ventilatory Assist Versus Pressure Support Ventilation During Noninvasive Ventilation. Respir Care. 67(7):879-888, 2022
5- Fang SJ, Chen CC, Liao DL, Chung MY: Neurally adjusted ventilatory assist in infants: A review article. Pediatr Neonatol. 64(1):5-11, 2023
6- Lefevere J, van Delft B, Decaluwe W, Derriks F, Cools F: Neurally adjusted ventilatory assist in preterm infants: A systematic review and meta-analysis. Pediatr Pulmonol. 59(7):1862-1870, 2024

Botulinum Toxin for Long Gap Esophageal Atresia

Long gap esophageal atresia (LGEA) is a rare but significant congenital condition, occurring in approximately 1 in 3,000 to 4,500 live births. The defining characteristic of LGEA is the presence of a substantial gap between the proximal and distal esophageal segments, often making primary anastomosis unfeasible. Traditional management approaches include delayed primary repair, organ interpositions, or esophageal replacement procedures, but these are frequently associated with high morbidity, prolonged hospital stays, and suboptimal functional outcomes. In recent years, the use of botulinum toxin (BTX), a neurotoxin derived from Clostridium botulinum, has emerged as a potential adjunct in managing LGEA by facilitating tissue elongation and reducing complications.


The mechanism of action of botulinum toxin lies in its ability to block the release of acetylcholine at neuromuscular junctions. This inhibition results in muscle relaxation, which can be exploited to reduce tissue tension in the esophagus. Initial experimental studies in animal models have demonstrated the efficacy of BTX in elongating esophageal tissue, with mechanical stress that often precludes successful primary anastomosis in LGEA.


Botulinum toxin (BTX) is applied intramurally to the esophageal musculature through precise injections, typically performed under direct visualization during surgery or using endoscopic techniques for minimally invasive delivery. The toxin is injected into multiple points along the esophageal wall, often at a dose of 2 units/kg per site, targeting both proximal and distal esophageal segments. Timing is crucial, with injections planned to allow BTX's peak effect, occurring around two weeks post-administration, to coincide with critical phases of elongation or repair. This method ensures localized muscle relaxation, enhancing tissue compliance and facilitating esophageal elongation while minimizing systemic effects.


Building upon these findings, further research explored the utility of BTX in a clinical context. In one randomized controlled trial, pig models with simulated esophageal atresia were treated with BTX prior to surgical interventions. The results demonstrated not only improved esophageal elongation but also a reduction in stricture formation and leakage rates post-anastomosis. The significant reductions in muscle tension observed in pig models. One study conducted in 2013 evaluated the intramural injection of BTX in piglets, showing that treated esophageal segments exhibited an 18% greater elongation under tension compared to controls. This finding underscored the potential of BTX to reduce the histological analysis further revealed that BTX-treated tissues exhibited more organized muscle regeneration and less collagen deposition at anastomotic sites, suggesting enhanced healing. These outcomes align with the hypothesis that BTX's muscle-relaxing and anti-fibrotic properties can mitigate some of the mechanical and biological challenges associated with esophageal repair.


The integration of BTX into surgical protocols for LGEA has also been studied in conjunction with advanced techniques such as the Foker process. This method, which relies on applying continuous tension to stimulate esophageal growth, is a cornerstone of modern LGEA management. However, its implementation is often limited by the prolonged sedation and immobility required for traction. A 2024 study investigating BTX-enhanced Foker procedures demonstrated that the addition of BTX significantly reduced the duration of traction, from an average of 16.6 days in traditional Foker processes to 12.1 days in BTX-enhanced protocols. This reduction not only minimizes the risks associated with prolonged sedation but also expedites recovery, highlighting the practical benefits of incorporating BTX into clinical practice.


Despite these promising results, challenges remain in translating BTX therapy from experimental and early clinical studies to routine use. One key consideration is the optimal timing of BTX administration. The toxin's peak effect typically occurs two weeks post-injection, suggesting that precise scheduling is crucial for maximizing its benefits during surgical planning. Additionally, concerns about potential side effects, such as transient dysphagia or gastroesophageal reflux due to temporary reductions in esophageal motility, warrant careful monitoring and further research.


The anti-fibrotic effects of BTX are another area of interest. By reducing smooth muscle spasms and the mechanical stress that contributes to scar formation, BTX may lower the incidence of refractory strictures—a common and debilitating complication of esophageal surgery. However, clinical data on long-term outcomes in human subjects remain sparse, and larger cohort studies with extended follow-up are necessary to confirm these findings.


Another intriguing application of BTX lies in its potential to enhance minimally invasive surgical techniques for LGEA. Thoracoscopic approaches, which are gaining popularity due to their reduced morbidity compared to open surgery, could benefit from the muscle-relaxing properties of BTX. Early studies suggest that BTX injections can facilitate the mobilization of esophageal segments, making minimally invasive procedures more feasible even in complex cases of LGEA.


The future of BTX in LGEA treatment appears promising, with ongoing research exploring new frontiers. For instance, the combination of BTX with regenerative medicine techniques, such as tissue engineering and stem cell therapies, could revolutionize the field. By creating bioengineered esophageal tissues pre-treated with BTX, it may be possible to further optimize surgical outcomes and reduce reliance on traditional, high-risk procedures.


In conclusion, botulinum toxin represents a novel and versatile tool in the management of long gap esophageal atresia. Its ability to reduce tissue tension, enhance elongation, and improve anastomotic healing positions it as a valuable adjunct in addressing the challenges of this complex condition. While further clinical studies are needed to refine its applications and establish standardized protocols, the integration of BTX into LGEA management has the potential to significantly improve outcomes for affected infants and their families. With ongoing advancements in both surgical techniques and pharmacological interventions, the role of BTX is likely to expand, offering new hope in the treatment of this challenging congenital anomaly.


References:
1- Ellebæk M, Qvist N, Rasmussen L: Secondary anastomosis after preoperative botulinum type A toxin injection in a case with long gap oesophageal atresia. Eur J Pediatr Surg. 23(4):325-6, 2013
2- Larsen HF, Jensen TS, Rasmussen L, Ellebæk M, Qvist N: Intramural injection with botulinum toxin significantly elongates the pig esophagus. J Pediatr Surg. 48(10):2032-5, 2013
3- Dibbern CB, Rose M, Ellebæk MB, Qvist N: The Effect of Intramural Botulinum Toxin Injections on the Elongation of the Piglet Oesophagus Is Time Dependent. Eur J Pediatr Surg. 27(1):56-60, 2017
4- Pike AH, Zvara P, Antulov MR, et al: Intramural Injection of Botulinum Toxin A in Surgical Treatment of a Long Gap Esophageal Atresia-Rat Model. Eur J Pediatr Surg. 30(6):517-523, 2020
5- Svensson E, Zvara P, Qvist N, et al: The Effect of Botulinum Toxin Type A Injections on Stricture Formation, Leakage Rates, Esophageal Elongation, and Anastomotic Healing Following Primary Anastomosis in a Long- and Short-Gap Esophageal Atresia Model - A Protocol for a Randomized, Controlled, Blinded Trial in Pigs. Int J Surg Protoc. 25(1):171-177, 2021
6- Izadi S, Koo DC, Shieh HF, et al: Botulinum Toxin Enhanced Foker Process for Long Gap Esophageal Atresia. J Pediatr Surg. 59(12):161628, 2024

Newborn Infant Parasympathetic Evaluation Monitor

The Newborn Infant Parasympathetic Evaluation (NIPE) monitor represents a significant advancement in neonatal and pediatric care, offering a non-invasive means of assessing pain and discomfort in infants under two years of age. The device, developed to measure parasympathetic activity through heart rate variability (HRV), provides an objective pain index, ranging from 0 to 100. This technology addresses longstanding limitations of traditional pain assessment methods, which have relied heavily on subjective observations and behavioral scales, such as the Premature Infant Pain Profile Revised (PIPP-R) and the Face, Legs, Activity, Cry, Consolability (FLACC) scale.


Traditional behavioral scales have several drawbacks, including high interobserver variability, time-intensive scoring, and limited applicability in deeply sedated or anesthetized patients. The NIPE monitor overcomes these issues by continuously analyzing high-frequency HRV to evaluate parasympathetic tone. A decrease in the NIPE score indicates heightened pain or stress, while an increase suggests improved comfort. The monitor generates instantaneous (NIPEi) and mean (NIPEm) indices, allowing real-time and averaged pain assessments, respectively.


Several studies have explored the utility of the NIPE monitor across various clinical settings, including acute pain during procedural interventions, intraoperative nociception, and postoperative pain management. However, the results have been mixed, highlighting both the potential and the limitations of this technology.


The NIPE monitor has been evaluated for its ability to detect acute procedural pain in preterm and term neonates. A 2020 study by Gendras et al. examined its effectiveness during routine painful and stressful procedures in preterm infants. While the NIPE index demonstrated high sensitivity and negative predictive value for predicting severe pain during skin-breaking procedures, no significant correlation was found between NIPE and PIPP-R scores during routine painful interventions. This raised concerns about its ability to fully capture acute pain responses, especially in less invasive procedures.


Other studies have similarly reported mixed findings. For instance, the monitor successfully detected significant decreases in NIPE scores during painful interventions, but its correlation with traditional pain scales like the Neonatal Acute Pain (DAN) scale was inconsistent. These discrepancies may stem from differences in patient demographics, procedural types, and study methodologies.


Intraoperative pain assessment is another area where the NIPE monitor shows promise. Traditional methods of evaluating nociception during surgery, such as observing changes in heart rate and blood pressure, are empirical and prone to variability. The NIPE monitor offers an objective alternative by continuously measuring parasympathetic activity. A 2024 systematic review highlighted the monitor's ability to detect nociceptive events like skin incisions and intubations during surgery, as well as insufficient analgesia. It also demonstrated high sensitivity and specificity for identifying pain.


However, the device's utility may be limited by the complexity of intraoperative pain management. For example, a study comparing open and laparoscopic inguinal hernia repairs found significant differences in NIPE scores, with laparoscopic procedures associated with greater pain despite similar analgesic regimens. This finding underscores the importance of contextual factors, such as the type of surgical intervention and the adequacy of regional anesthesia.


Postoperative pain assessment has also been explored using the NIPE monitor. A 2023 prospective study demonstrated a weak but statistically significant correlation between intraoperative NIPE indices and postoperative FLACC scores. This association was strongest immediately after surgery but diminished over time, likely due to the administration of postoperative analgesia. The findings suggest that while the NIPE monitor can predict early postoperative pain, its utility may decrease as external factors, such as analgesic interventions, modify the pain response.


Another study compared pain outcomes in infants undergoing open versus laparoscopic hernia repairs. Postoperative NIPE scores were significantly lower in the laparoscopic group, reflecting higher pain levels. These results highlighted the monitor's ability to objectively differentiate pain levels between surgical approaches, providing valuable insights for tailoring postoperative care.


Beyond pain assessment, the NIPE monitor has been used to evaluate comfort and stress levels in neonates. Studies have shown increased NIPE scores during interventions promoting comfort, such as skin-to-skin contact and facilitated tucking. However, these findings are not universal, with some studies reporting no significant changes during specific comfort measures. The variability in results underscores the need for further research to clarify the monitor's role in non-pain-related assessments.


While the NIPE monitor offers several advantages, its adoption in clinical practice faces challenges. One major limitation is its inconsistent correlation with traditional pain scales, which remain the gold standard for pain assessment. The reliance on HRV as a sole indicator of pain may overlook other physiological and behavioral components of the pain response.


Another issue is the heterogeneity of study populations and methodologies. Variations in gestational age, clinical settings, and procedural types make it difficult to generalize findings. Furthermore, the monitor's accuracy in detecting subtle changes in parasympathetic activity may be influenced by confounding factors such as medication use, underlying medical conditions, and environmental stressors.


Finally, the NIPE monitor's primary focus on parasympathetic activity may limit its applicability in conditions were sympathetic responses dominate. For instance, pain responses involving significant sympathetic activation may not be adequately captured, reducing the monitor's overall sensitivity.


Despite these challenges, the NIPE monitor holds promise as a valuable tool for neonatal and pediatric pain assessment. To fully realize its potential, further research is needed to address existing limitations. Large-scale, multicenter studies with standardized protocols are essential for validating its accuracy and reliability. Additionally, integrating the NIPE monitor with other pain assessment methods, such as behavioral scales and biochemical markers, could enhance its clinical utility.


Advances in technology may also improve the monitor's performance. For example, refining the HRV algorithm to account for individual variability and incorporating machine learning techniques could increase its sensitivity and specificity. Expanding its use to other clinical settings, such as the evaluation of chronic pain and stress, could further broaden its applications.


The Newborn Infant Parasympathetic Evaluation monitor represents a significant step forward in the objective assessment of pain and discomfort in neonates and infants. While its utility has been demonstrated in various clinical settings, including procedural pain, surgery, and postoperative care, inconsistencies in findings highlight the need for further research. With continued refinement and validation, the NIPE monitor has the potential to revolutionize pain management and improve outcomes for this vulnerable population.


References:
1- Gendras J, Lavenant P, Sicard-Cras I, Consigny M, Misery L, Anand KJS, Sizun J, Roué JM: The newborn infant parasympathetic evaluation index for acute procedural pain assessment in preterm infants. Pediatr Res. 89(7):1840-1847, 2021
2- Recher M, Boukhris MR, Jeanne M, Storme L, Leteurtre S, Sabourdin N, De Jonckheere J: The newborn infant parasympathetic evaluation in pediatric and neonatology: a literature review. J Clin Monit Comput. 35(5):959-966, 2021
3- Ivanic S, Tong LS, Laird A, Malhotra A, Nataraja RM, Lang C, Pacilli M: The Newborn Infant Parasympathetic Evaluation (NIPE™) monitor predicts post-operative pain in children undergoing day-procedures: A prospective observational study. J Pediatr Surg. 58(4):684-688, 2023
4- Manzar S: Does the Newborn Infant Parasympathetic Evaluation Monitor Predict Post-Operative Pain? J Pediatr Surg. 58(9):1852, 2023
5- Sakthivel M, Su V, Nataraja RM, Pacilli M: Newborn and Infant Parasympathetic Evaluation (NIPE™) Monitor for Assessing Pain During Surgery and Interventional Procedures: A Systematic Review. J Pediatr Surg. 59(4):672-677, 2024
6- Sakthivel M, Bapna T, Ivanic S, Lang C, Nataraja RM, Pacilli M: An Objective Evaluation of Intraoperative and Postoperative Pain in Infants Undergoing Open Inguinal Herniotomy and Laparoscopic Inguinal Hernia Repair Using the Newborn Infant Parasympathetic Evaluation (NIPE™) Monitor. J Pediatr Surg. 60(2):161651, 2025



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