PSU Volume 50 No 01 JANUARY 2018

Bilateral Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) includes the anterior Morgagni hernia, hiatal hernia and the posterolateral Bochdalek hernia. Most CDH are Bochdalek type (85%). Bilateral CDH is extremely rare occurring in 1% of all CDH cases. Most of them die in utero while 25-35% of them survive. Antenatal diagnosis is possible with ultrasonography showing minimal mediastinal shift, bowel In thorax, small abdominal circumference and polyhydramnios. The prognosis of CDH depends on the degree of pulmonary hypoplasia and pulmonary hypertension caused by the intrinsic intrauterine pressure of the defect on the developing lung of the fetus. Furthermore a higher prevalence of major congenital anomalies (chromosomal and cardiac) has been reported for bilateral when compared with unilateral CDH. A prenatal diagnosis is more frequent among non-survivors compared to survivors due to the challenging nature of establishing the diagnosis of bilaterality. The patient with the largest defect and smaller lungs carries the worst prognosis. Most bilateral CDH usually have an acute presentation, but if the pulmonary impairment is subtle it can have a delayed presentation with an excellent prognosis. The rate of surgical repair of bilateral CDH is 50%. Most of these cases of bilateral CDH are repaired with a subcostal abdominal incision, though there has been scattered reports of staged bilateral thoracoscopic repair. Two-third of repaired cases will need a patch. Larger defect size, needing a patch repair, correlates with a more severe disease and mortality. The mortality of patients with bilateral CDH using ECMO is significantly larger that with unilateral CDH. 60% of the surviving patients are in need of pulmonary support at 30 days of life which would indicate a similar poor long-term prognosis of bilateral CDH patients at one and five years. Lower Apgar scores, prenatal diagnosis, the need for ECMO treatment, and patch repair have shown to be associated with higher mortality.

Extremity Compartment Syndrome

Acute compartment syndrome is a surgical emergency caused by an increase in the interstitial pressure within a closed muscle compartment of an extremity causing decrease perfusion of muscles and nerves. It can be the result of external compressing or internal expansion forces within an enclosed fascial compartment. Most cases of compartment syndrome are associated with trauma (80%), namely tibial and forearm fractures followed by nontraumatic causes (20%) such as ischemic-reperfusion event after arterial injury, thrombosis, burns, bleeding disorder, infection and blunt injury. The normal pressure in a muscle compartment is less than 12 mm Hg. Swelling of injured muscle raises the intracompartment pressure closing lymphatics vessels and small venules. Early presentation there is perifascicular and intrafascicular edema, hypertension in the capillary bed, and compression of arterioles, all of which worsen the ischemia. Blood flow in the capillary circulation ceases when compartment pressures exceed 35 mm Hg. The sensory nerves are affected first, followed by the motor nerves and muscles, fat and skin become involved later. The skin is the most resistant to ischemia. Untreated compartment syndrome causes irreversible neurologic damage, muscle necrosis, myoglobinuria, renal failure and fibrous contracture (Volkmann). Symptoms include pain, pallor, paresthesia, paralysis and pulselessness. Management consists of urgent decompressive fasciotomy. Measurement of the compartment pressure by needle or using near-infrared spectroscopy showing values higher than 30 mm Hg (or 20 mm Hg below diastolic pressure) should undergo fasciotomy. For upper limbs decompression can be achieved via volar or dorsal approach or both. In the lower extremity four-compartment decompression can be achieved b a single or double incision technique. Decompression of the thigh can be achieved via medial or lateral incision. Complications of fasciotomy include infection, iatrogenic nerve or blood vessel injury and muscle damage. Complications associated with the fasciotomy scar includes paresthesia, pruritus and pain.

References:
1- Ramos C, Whyte CM, Harris BH: Nontraumatic compartment syndrome of the extremity in children. J Pediatr Surg 41: E5-E7, 2006
2- Dover M(1), Memon AR, Marafi H, Kelly G, Quinlan JF: Factors associated with persistent sequelae after fasciotomy for acute compartment syndrome.J Orthop Surg (Hong Kong). 20(3):312-5, 2012
3- Erdos J, Dlaska C, Szatmary P, Humenberger M, Vilmos V, Hajdu S: Acute compartment syndrome in children: a case series in 24 patients and review of the literature. Int Orthop. 35(4):569-75, 2011
4- Tharakan SJ, Subotic U, Kalisch M, Staubli G, Weber DM: Compartment Pressures in Children With Normal and Fractured Forearms: A Preliminary Report. J Pediatr Orthop. 36(4):410-5, 2016
5- von Keudell AG, Weaver MJ, Appleton PT, Bae DS, Dyer GSM, Heng M, Jupiter JB, Vrahas MS: Diagnosis and treatment of acute extremity compartment syndrome. Lancet. 386(10000):1299-1310, 2015
6- Elmhiregh A, Feghih AE, Faraj K: Concomitant unilateral post-traumatic leg and foot compartment syndrome in a 5 years-old child - Case report. Int J Surg Case Rep. 33:151-157, 2017

Subcutaneous Abscess in Children

Subcutaneous abscess are fairly common condition encounter in children. The rise in community cases of methicillin resistant staphylococcus Aureus (MRSA) infection has led to a similar rise in number of  skin infection and abscess formation requiring surgical drainage. These MRSA soft tissue infections often present as more complicated forms of subcutaneous abscess usually necessitating wide incision and drainage procedures for appropriate care. Communities have reported a prevalence of MRSA at 66-74% among pediatric patients undergoing surgical intervention. The toddler population with less than three years of age is at greater risk due to lack of formal toilet training and use of diaper that promotes bacterial propagation. Standard management of subcutaneous abscess, especially those measuring more then five centimeters,  is incision and drainage followed by packing in the wait of secondary healing. Children are unable to perform their own wound care, and caretakers often struggle with wound packing and dressing changes. Minimal invasive technique has been developed to drain these complicated abscess. Intravenous antibiotics are needed when cellulitis and leukocytosis are present. Instead of large drains such as Penrose, small drains such as vessel loops or rubber bands are used to accomplish the task after manipulation of the loculations of the abscess followed by irrigation with normal saline. Vessel loops are used in patients with known latex allergy by all surgeons. The use of a loop drain is safe and effective in the treatment of subcutaneous abscesses in children. Packing gauze is not always needed. Because of the increasing incidence of community-acquired S Aureus soft tissue infections, sulfamethoxazole/trimethoprim or clindamycin, was used empirically for a total of 10 to 14 days. The content of all abscess is swabbed for culture routine, though this not makes a significant process as the results are usually available when the child is recovering from the abscess satisfactorily.

References:
1- Ladd AP, Levy MS, Quilty J: Minimally invasive technique in treatment of complex, subcutaneous abscesses in children.  J Pediatr Surg. 45(7):1562-6, 2010
2- Tsoraides SS, Pearl RH, Stanfill AB, Wallace LJ, Vegunta RK: Incision and loop drainage: a minimally invasive technique for subcutaneous abscess management in children.  J Pediatr Surg. 45(3):606-9, 2010
3- McNamara WF, Hartin CW Jr, Escobar MA, Yamout SZ, Lau ST, Lee YH: An alternative to open incision and drainage for community-acquired soft tissue abscesses in children.J Pediatr Surg. 46(3):502-6, 2011
4- Leinwand M, Downing M, Slater D, Beck M, Burton K, Moyer D: Incision and drainage of subcutaneous abscesses without the use of packing.  J Pediatr Surg. 48(9):1962-5, 2013
5- Aprahamian CJ, Nashad HH, DiSomma NM, Elger BM, Esparaz JR, McMorrow TJ, Shadid AM, Kao AM, Holterman MJ, Kanard RC, Pearl RH: Treatment of subcutaneous abscesses in children with incision and loop drainage:  A simplified method of care. J Pediatr Surg. 52(9):1438-1441, 2017

PSU Volume 50 NO 02 FEBRUARY 2018

Gardner Fibroma

Gardner fibromas are superficial, poorly circumscribed benign soft tissue tumors and sometimes painful lesions which consist mainly of thick haphazardly arranged collagen bundles with few interspersed spindle cells of fibroblast type. Males and females are equally affected. They are associated with Gardner syndrome and may be the first manifestation of the disease. Gardner fibromas are precursors lesion of desmoid tumors. Both Gardner fibromas and desmoid tumors are associated with Gardner syndrome. Gardner syndrome is an autosomal dominant inherited disease characterized by the triad of gastrointestinal adenomatous polyps, multiple osteomas and mesenchymal tumors of the skin and soft tissue. Gardner syndrome and Familial adenomatous polyposis (FAP) are considered to be variants of the same disease. Both are caused by mutation in the APC gene located on chromosome 5q21. The cutaneous and bone abnormalities precede development of polyposis with approximately 10 years. Other cutaneous manifestations of Gardner syndrome include neurofibromas, lipomas, leiomyomas and pigmented skin lesions. The diagnosis of Gardner syndrome can be made by genetic testing or by colonoscopy showing multiple polyps. The most common sites affected by Gardner fibromas include the back, paraspinal region and chest wall though they may appear in any part of the body. Gardner fibromas are most commonly observed in the first decade of life. The management of a Gardner fibroma consists of wide total local excision something that can be technically demanding or even impossible because of the poor circumscription or anatomic boundaries this type of tumor is characterized. Prediction of Gardner fibroma behavior is impossible, but in general 5-10% resolve spontaneously, 30% undergo cycles of progression and resolution and 50% remain stable after diagnosis, but 10% progress rapidly growing to massive sizes and infiltrating adjacent tissue. The development of a Gardner fibroma raise sentinel suspicion of Gardner syndrome or FAP which should be diagnosed by endoscopy or genetic testing.

Renal Rhabdoid Tumor

Renal rhabdoid tumors (RRT) are highly malignant neoplasms first described in the kidney of young children. Rhabdoid tumors also arise in extra-renal sites such as soft tissue and central nervous system. RRT have a common genetic abnormality, namely the mutation or deletion of the SMARCB1/hSNF5/INI-1 gene located at chromosome 22q11.2. A concomitant brain tumor is present in almost 21% of children with a RRT. The exact cell type of derivation of Rhabdoid tumors of the kidney remains unknown though a possible origin has been ascribed to primitive cells located in then renal medulla. Histologically RRT cells are arranged as diffuse sheets or as alveolar or trabecular pattern. RRT can occur sporadically or as part of hereditary cancer syndrome known as Rhabdoid Tumor Predisposition Syndrome. Prognosis of malignant rhabdoid tumor of the kidney is related to age at time of diagnosis and stage of disease and not to the location of the tumor. The younger the child with RRT the less probable is his long-term survival. Older than age 1.5 years at diagnosis regardless of anatomic location has higher overall survival. RRT is commonly diagnosed between 0-3 years of age with a peak incidence between age of 10-18 months. It is also associated with extensive metastasis at time of diagnosis and as mentioned before can have synchronous brain tumor. There is no standard management for RRT and the prognosis is very poor with overall survival of 15-36% though more recent treatment regimens using surgery, radiotherapy, high dose chemotherapy and autologous stem cell rescue may increase survival to 66.7%with a median follow up of almost two years. Surgical treatment of RRT follows that used in Wilms tumor. Biopsy of the primary tumor is usually not carried out prior to removal to avoid rupture of the tumor capsule and spillage of tumor cells. Germline analysis is recommended for individuals of all ages with rhabdoid tumors and prenatal diagnosis can be performed in families with a known SMARCB1 alteration. Surveillance guidelines for patients with germline mutation have been developed.

Endocarditis Prophylaxis

Infective endocarditis is a rare potentially life threatening infection of the heart valve or endocardium. Congenital heart disease (CHD) and palliative or corrective surgery associated to the structural defect are the two most common predisposing conditions for the development of infective endocarditis. Cyanotic CHD, left-sided lesions and endocardial cushion defects are associated with increase risk of infective endocarditis in children. The risk of developing infective endocarditis is substantially elevated during the six months postoperative period of cardiac surgery and in children less than three years of age. Lesions associated with cyanosis at birth (dextrotransposition of great arteries and tetralogy of Fallot) has the highest incidence of infective endocarditis. Infective endocarditis is less common in right sided than left sided lesion. Endothelialization of prosthetic material introduced by cardiac surgery occurs within six months following the procedure. The most common organism covered during endocarditis prophylaxis is Streptococcus viridans a commensal bacteria that populate the skin, oral, gastrointestinal and respiratory mucosa. The American Heart Association guidelines recommend providing prophylactic antibiotic coverage for endocarditis to children who are to undergo a procedure including dental which has an unrepaired cyanotic CHD including palliative shunts and conduits, completely repaired CHD with prosthetic material or device (whether placed by surgery or catheter intervention) during the first six months after the procedure. Also prophylaxis is recommended for repaired CHD with residual defect at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization)  and cardiac transplantation recipients who develop cardiac valvulopathy. Any child with CHD undergoing a general surgery or dental procedure should be evaluated by its pediatric cardiologist in seek of advice regarding endocarditis prophylaxis. Procedures that require prophylaxis include dental including manipulation of gingival tissue or perforation of oral mucosa, tonsillectomy and adenoidectomy. Endocarditis prophylaxis is no longer needed for gastrointestinal and genitourinary procedures since they all receive broad spectrum prophylaxis by nature of the clean contaminated classification.

PSU Volume 50 NO 03 MARCH 2018

Peliosis

Peliosis hepatis (PH) is a very rare benign disease characterized by multiple small blood-filled cysts of various sizes and shape  within the liver parenchyma. Peliosis comes from the Greek word ‘pelios' that means reddish or bluish (extravasated blood). What triggers PH is unknown, but dilation of sinusoids might be due to an altered outflow damaging the sinusoid wall and creating dilation of the central vein of the hepatic lobules. Peliosis can be focal or widespread with most cases involving the right hepatic lobe. Peliosis can also occur on other organs such as the spleen, bone marrow, lymph nodes, etc. Etiologic factors associated with PH include drugs, autoimmune mechanisms and infectious causes. Drugs associated with PH include steroids, oral contraceptives, tamoxifen, methotrexate, thiopurine, azathioprine and iron chelators. Alcohol consumption can trigger PH. Imaging studies such as CT-Scan and MRI angiography suggest the diagnosis, but cannot be precised enough since PH cannot be differentiated from adenomas, hemangiomas, focal nodular hyperplasia, Caroli disease or multiple abscess. Lesions are from few millimeters in diameter to 4 cm. Ultrasound may show a pseudocystic lesion of the hepatic parenchyma with intra- or perilesional vascularity. Angiography demonstrates multiple hypervascularized nodules during the late arterial phase with enhancement more pronounced during the parenchymal phase which persists during the venous phase. MRI when combined with hepatospecific contrast material represents the gold standard for radiological diagnosis of PH. Due to the high risk of bleeding an open biopsy using intraoperative US is needed to establish the diagnosis of PH. The disease can cause stenosis of the vena cava when developed in young age. Though mainly asymptomatic, PH can rupture and produce spontaneous hemoperitoneum. Management is usually in the acute setting due to bleeding and consists of either hepatic lobectomy, transplantation or percutaneous embolization.

Renal Clear Cell Sarcoma

Childhood renal tumors account for 7% of all pediatric cancers. Most cases (90%) are Wilms tumor. Renal Clear Cell Sarcoma (RCCS) is a rare and very aggressive pediatric tumor characterized for its tendency to metastasize to bone often called the bone metastasis renal tumor of children. The term clear cell sarcoma relates to the presence of numerous intracytoplasmic vesicles present in the tumor histology. Other features that differentiate RCCS from Wilms tumor are that they are unicentric in the medullary region of the kidney with foci of necrosis and cyst formation. RCCS is the second most common malignant kidney tumor in children after Wilms tumor comprising approximately 4-6% of all pediatric renal tumors. RCCS is not associated with genetic predisposition syndrome and familial cases have not been reported. RCCS is rare below the age of one year, have a peak incidence between three and five years of age and are more common in males patients. Metastasis from RCCS can also occur to lymph nodes, lungs, liver and brain. RCCS occurs in the same age range as Wilms tumor with no specific radiological features to help distinguish one from the other. Grossly RCCS include large tumor size (more than 10 cm in diameter), mucoid texture, foci of necrosis and prominent cyst formation. Nine histologic different patterns of RCCS have been described. The four important prognostic factors associated with RCCS include treatment with doxorubin, beyond stage I, age at diagnosis greater than two years and tumor necrosis. Management of RCCS at all stages requires aggressive surgical approach followed by chemotherapy and radiotherapy as per NWTS-5 protocols.  Overall survival after treatment is 69%. Relapse rates are high and often occur late. Adverse prognostic factors identified are young age, advanced stage IV disease and those with relapse disease.

Prophylactic Thyroidectomy

Prophylactic removal of all the thyroid gland (total thyroidectomy) is curative treatment for children at risk of developing medullary thyroid cancer (MTC) caused by mutation in the RET proto-oncogene. Medullary thyroid cancer arises from the parafollicular cells which are responsible for secreting calcitonin. Calcitonin is a sensitive and specific tumor marker for MTC. MTC has an early and high penetrance in hereditary syndrome caused by the RET mutations including multiple endocrine neoplasia (MEN) type 2A and type 2B, and familial MTC which progress to regional lymph nodes and distant metastasis if left unmanageable. The vast majority of MTC in children is hereditary. Children with MEN 2A, MEN 2B and familial MTC can be followed after total prophylactic thyroidectomy with calcitonin levels to monitor for recurrence or development of MTC. Thyroglobulin, a protein precursor of thyroxine produced by the thyroid follicular cells can be a useful test following prophylactic thyroidectomy since many times surgeons leave behind thyroid tissue specially in the nearby region of the recurrent laryngeal nerve (Zuckerkandl tubercle or ligament of Berry). If thyroglobulin is high, an US should be performed to quantify how much residual thyroid tissue was left behind since it has parafollicular cells that can become MTC. Children with MEN2B should go RET genetic analysis and genophenotype ranking or risk level at birth and those with MEN2A and familial MTC before age of five years. Age of prophylactic thyroidectomy recommended include before the first year of age for those MEN children with RET gene mutation and highest genophenotype risk (ATA-D), before age five years for RET mutation and lower risk (ATA-C) and before 10 of age with the minimal risk (ATA-B and ATA-A) or familial MTC. During prophylactic thyroidectomy central lymph node removal is not warranted unless the child has elevated calcitonin level (> 40 pg/mL) with clinical MTC. Annual calcitonin level is needed in all cases and if abnormal thyroidectomy should be performed immediately. The high rate of postoperative hypocalcemia in very young children undergoing prophylactic thyroidectomy has hampered others not to recommend it before the age of three years.

PSU Volume 50 No 04 APRIL 2018                          

Toxic Colitis

Toxic colitis (TC) refers to an acute severe colitis which threatens life of the child. When associated with megacolon it is called toxic megacolon (TM). Toxic megacolon is an acute dilatation of the colon associated with symptoms of toxemia such as abdominal distension, constipation, reduced bowel sounds and fever, tachycardia or hypotension. The colonic dilatation can be total or segmental depending on the incipient disease that cause it. Patients can develop toxicity without megacolon.  The hallmark of toxic megacolon (or colitis) is a nonobstructive transverse colonic dilatation larger than 6 cm associated with signs of systemic toxicity such as fever above 101.5 F, tachycardia and leukocytosis or anemia. The child might also present bloody stools, dehydration, altered metal status, electrolytes abnormalities and hypotension. Toxic colitis (or megacolon) is mostly a complication of ulcerative colitis but can be seen in other inflammatory disease such as Crohn, ischemic colitis, infectious colitis associated with Clostridium difficile, after radiation therapy or with Hirschsprung's disease.  The most dreaded complication of toxic colitis with megacolon is perforation of the colon. Since many children with ulcerative colitis are in steroid therapy, the classic signs of peritonitis are absent when free perforation occurs due to a blunt systemic inflammatory response from the steroids. The microscopic hallmark of TC or TM is transmural inflammation extending beyond the mucosa into the smooth-muscle layers and serosa. The extent of dilatation correlates with the depth of inflammation and ulceration. Medications such as anticholinergics, antidepressants, loperamide and opioids negatively impact bowel motility and could be implicated in cases of TM. The prognosis with medical management of TM is poor though with tumor necrosis factors alpha inhibitors more cases can be managed medically. When TC or TM is established surgery will be needed. Total colectomy with ileostomy is the procedure of choice in the very acute situation. Later proctectomy with j-pouch ileal reconstruction can be performed.

Musculoskeletal Deformity after Thoracotomy

Posterolateral thoracotomy is the most common surgical approach for thoracic and cardiovascular procedures in children. This type of procedure many times is performed dividing the latissimus dorsi and serratus anterior muscle which results in postoperative muscular atrophy hence the development of thoracic and spinal deformities. The thoracotomy incision can result in long-term physical impairment and chest wall deformity. Typical deformity findings after thoracotomy includes wing scapula, anterior chest wall deformity, rib fusion and scoliosis. Damage to the innervation of the serratus anterior muscle can contribute to the chest wall deformity. The rate of sequela is not affected by age or birth weight at time of the procedure. The majority of deformities develop at three to four years after surgery thus a long follow up is needed to evaluate these children for musculoskeletal deformities. Musculoskeletal deformity develops in 25% of children who have undergo one or more thoracotomies. Division of the serratus anterior muscle is the only independent risk factor associated with an increased incidence and risk of developing a musculoskeletal deformity. The incidence rate of any musculoskeletal deformity (scoliosis, scapular winging or chest wall anomaly) in children who had undergone a right posterolateral thoracotomy for repair of esophageal atresia is 2.92 per 100 child-year. A rate which decreases to 1.82 when muscle sparing thoracotomy is utilized preserving both the serratus anterior and latissimus muscle. Muscle sparing thoracotomy does diminish the postoperative occurrence of musculoskeletal deformity. A classic muscle-sparing thoracotomy often allows excellent exposure of the lung and thoracic structures in neonates, infants, and young children. Ribs should never be resected in children. Tight closure can lead to rib fusion and increase the chances of chest asymmetry and deformity. Rib fusion takes longer to developed and leads to thoracogenic scoliosis. Thoracoscopy has less impact on the thoracic wall compared with open thoracotomy.    

Sclerotherapy for Rectal Prolapse

Rectal prolapse is a relatively common condition in children with a peak incidence between one and three years of age when toilet training is occurring. Male predominance occurs in most cases. Rectal prolapse can be partial when only protrusion of the mucosa from the anal verge occurs, or complete when the full thickness of the rectum prolapses. The cause of rectal prolapse can be anatomic such as a vertical configuration of the sacrum, greater mobility of the sigmoid colon, loose attached rectal mucosa and absence of Houston's valve in most cases. Children with prolapse have lower basal and squeeze pressures during anorectal manometry when compared with normal control. Diagnosis of rectal prolapse is made by physical exam and history. Prolapse of mass, bleeding after defecation, diarrhea, prolapse rectum and constipation are the most common signs and symptoms. Most (> 80%) children with rectal prolapse do not need specific surgical treatment if constipation, parasites and excessive straining are managed. Children that fail medical therapy will eventually need some surgical management. Injection sclerotherapy is the first surgical method used to manage rectal prolapse and is likely to cure the child with one or two injections 80% of the time. Transrectal sclerotherapy is performed with 50% saline solution, ethyl alcohol or cows milk. A volume of 0.50 ml/kg of sclerosant divided over four quadrants appears a prudent volume to managed rectal prolapse. Older scholar children and those overweight are likely to experience recurrence eventually needing an operation. If sclerotherapy fails then the Thiersch procedure is recommended. The Thiersch procedure is a minimally invasive procedure involving placing a suture encircling the anal canal under the skin. The aim is to narrow the relaxed anal sphincter and cause proliferation to form adhesions within the surrounding tissue. If sclerotherapy and Thiersch procedures fail, then other more sophisticated major abdominal or perineal procedure such as stripping of the mucosa or rectopexy should be used.     

PSU Volume 50 No 05 MAY 2018

Non-Immune Hydrops

Hydrops is the accumulation of extravascular fluid within two or more cavities of the fetus within the utero which may include ascites, pleural or pericardial effusions or skin or trunk edema, anasarca and placentomegaly appearing in advanced stages. Polyhydramnios develop due to pressure on the esophagus and decreased swallowing of amniotic fluid. Hydrops result from various underlying congenital anomalies that cause increased central vascular pressure, decrease lymph flow or decreased plasma oncotic pressure leading to a net imbalanced of fluid movement between the intravascular and interstitial compartments. Non-immune hydrops (NIH) is the most common cause of hydrops in the fetus since Rh alloimmunization or immune hydrops is rare due to routine immunization of Rh negative mothers. Congenital infections account for up to 8% of cases of NIH. NIH can occur in the fetus with chest occupying lesions or highly vascularized tumors that compress the mediastinum or increase cardiac demands respectively. Chest occupying lesions compress heart, SVC, IVC or ductus venosus leading to impaired atrial venous return and low output cardiac failure. Vascularized tumors causes high output cardiac failure from arteriovenous shunting and marked vascularity. Either way the perinatal mortality of NIH is very high. Prenatal ultrasound and echocardiography diagnose, predict outcome and dictate management of fetus with NIH. Patients with NIH who are able to have fetal intervention for their underlying condition benefits from improved survival especially when hydrops resolve ad there is no preterm delivery. Echocardiographic findings of NIH deterioration are the best predictors of the need of fetal surgical resection for fetuses with high-risk lung masses. Well-recognized causes of recurrent NIH are homozygous alpha-thalassemia and metabolic storage disorders such as mucopolysaccharidosis, Gaucher's, sialidosis and gangliosidosis. It is important to detect NIH early, diagnose the underlying cause and institute appropriate treatment. There is need for autopsy of all fetuses or neonates who die from NIH.

Laparoscopic CO2 Embolism

Laparoscopic procedures using carbon dioxide as insufflating gas can alter circulatory, pulmonary, renal, splanchnic and endocrine function in some patients. Cardiac arrest has been reported in one of every 65,000 laparoscopic procedures with a mortality rate of 28%. Cardiac arrest is related to a vasovagal response after rapid peritoneal distension and CO2 gas embolism as detected by transesophageal echocardiography (TEE). CO2 embolism is a very rare but potential serious complication. It is caused by entrapment of carbon dioxide in an injured vein, artery or solid organ resulting in blockage of the right ventricle or pulmonary artery. Laparoscopic CO2 embolism has been reported in various surgical procedures. Most serious cases occur during the beginning of the procedure due to Veress needle misplacement directly into a vein or solid organ. Late onset embolism is due to an injured vessel in the abdominal wall or operative site. Clinical manifestations depend on volume of CO2 entering the circulation and that which is removed with ventilation. It causes a gas lock effect obstructing right ventricular ejection, right and left cardiac failure, paradoxical embolism with or without a patent foramen ovale, arrhythmia, pulmonary hypertension and cardiovascular collapse. CO2 embolism does not cause the bronchoconstriction or changes in pulmonary compliance seen during air embolism. The patient develops hypotension, dyspnea, cyanosis, tachycardia, bradycardia, arrhythmia and asystole. TEE is the most sensitive method to diagnosed laparoscopic CO2 embolism. Other less sensitive methods include transesophageal or precordial Doppler and ETCO2. Preventive measures include correct position verification of Veress needle, use of low insufflating pressures, reverse Trendelenburg position and increasing the end-expiratory pressure. Management must be expeditious and include discontinuing CO2 insufflation and releasing the pneumoperitoneum, hyperventilating the patient with 100% oxygen, volume expansion to elevated the CVP, vasopressors, inotropic agents to maintain cardiac output, and hyperbaric oxygen therapy specially for neurologic deficit caused by cerebral gas emboli.       

Vacuum Bell Device

Pectus excavatum is the most common chest wall deformity in children occurring in approximately one in 300 live births. Initially pectus excavatum in children was managed surgically using the open Ravitch technique until Nuss developed a minimal invasive technique using a bar in 1998 to repair satisfactorily the defect. The Nuss technique is operator dependent with a small but significant number of potential complications associated with a learning curve and number of cases performed. Conservative management of pectus excavatum can be carried out using a glass bell to elevate the sternum called the Vacuum bell (VB). The Vacuum bell is a suction cup that creates a vacuum on the anterior chest wall and is activated by a patient-controlled hand pump. There are three types of VB - 16, 19 and 26 cm in diameter and a model fitted for women. The device is used at home for a minimum of 30 minutes twice a day during 4-6 weeks afterward it can be used up to a maximum of several hours daily. VB therapy is indicated in patients with mild pectus excavatum or who wish to avoid a surgical procedure. It is also used in preparation for surgery, if a surgical implantable bar has to be removed earlier than scheduled, and as intraoperative vacuum device to lift the sternum away from the heart during the Nuss procedure and avoid the dreaded complication of heart rupture. Contraindications for VB include musculoskeletal disorders, vasculopathies, coagulopathies and cardiac disorders. Complications of VB therapy include subcutaneous hematoma, petechial bleeding, dorsalgia and transient paresthesia of the upper extremities during application of the device. For this therapy to have success the child must be motivated and be compliant with treatment. All children are encouraged to continue sporting activities and physiotherapy in order to improve body control. VB therapy is recommended to be started before the age of 10 years. Duration of treatment can be from 12 to 36 months.        

PSU Volume 50 NO 05 MAY 2018

Neonatal Hyperparathyroidism

Neonatal severe hyperparathyroidism (NSHPT) is a very rare autosomal recessive disease presenting in children during early infancy, usually within the first six months of life though the majority of cases occur in the first few weeks. Babies present with signs of hypercalcemia and hyperparathyroidism including poor feeding, polyuria, dehydration, lethargy, failure to thrive, hypotonia, gastrointestinal dysmotility, osteopenia and respiratory distress due to poorly developed chest cage. Early diagnosis and management of NSHPT is critical due to high morbidity, mortality and devastating effect to neurodevelopmental status. Calcium sensing receptors (CASR) are the major sensors of serum calcium level and have a critical role in maintaining calcium homeostasis. CARS are present in parathyroid chief cells and epithelial lining of renal tubules. The human CASR gene maps to 3q13.3. Through this receptor serum calcium higher than the set point inhibits the parathyroid hormone release from chief cells preventing renal tubular reabsorption of calcium. Mutation of the CASR causes loss or gain of function of the receptor. Heterozygous mutation of CASR results in familial hypocalciuric hypercalcemia and homozygous loss of function mutation results in NSHPT due to uncontrollable release of parathyroid hormone and severe hypercalcemia. Management of NSHPT hypercalcemia initiates with aggressive hydration and forced diuresis with furosemide and use of calcitonin which may provide some transient improvement in heterozygous cases. Homozygous cases do not respond well. Treatment could be escalated to the use of bisphosphonate therapy and calcimimetic such as Cinecalcet which is effective in heterozygous cases. If the child does not respond to medical therapy due to the homozygous state of the mutation then will require early parathyroidectomy. Total parathyroidectomy is performed without autotransplantation due to the high incidence of recurrence of the disease. Localization of parathyroid glands preoperative using Sestamibi nuclear scan and MRI influence the surgical approach.

Incarcerated Inguinal Hernia Revisited

Inguinal hernia is the common surgical condition in children affecting almost 30% of premature infants. Inguinal hernia results from an incomplete obliteration of the processus vaginalis developed around the 6th month of fetal development. Most inguinal hernia in children are indirect. Incarcerated inguinal hernia is a common and serious emergent situation in pediatric patients. The risk of incarceration in children with inguinal hernia fluctuates between 3 and 16% with the highest incidence of 30% in premature. The rate of inguinal hernia strangulation is also higher in prematurely born infants.  The median age of presentation of inguinal hernia is two years. Incarcerated inguinal hernia occurs in 12% of all cases at a mean age of 1.5 years, mostly in boys and mostly on the right side. Due to the significant incidence of incarceration of inguinal hernia, once diagnosed inguinal hernias in children should be repair within the next two weeks. The management of incarcerated inguinal hernia is manual reduction which is successful in most cases, followed by open repair of the hernia in the next 48-72 hours once the edema of the cord has subsided. The procedure can also be done laparoscopically. The advantage of laparoscopic incarcerated inguinal hernia repair include excellent visual exposure, reduction of the incarcerated viscera and inspection for gangrene, immediate repair of the defect, the ability to evaluate the contralateral side, minimal dissection and avoidance of access trauma to the vas deferens and the testicular vessels, iatrogenic ascent of the testis and decreased operative time specially in obese and recurrent cases. The cons are that a subcutaneous procedure is converted into a transabdominal procedure with the incidence of adhesions and later bowel obstruction development. In the case of female patients the possibility of having an incarcerated ovarian inguinal hernia is high. The use of US to determine if an ovary is incarcerated can provide evidence of flow and plan urgent surgery before torsion occurs. Both open herniotomy and laparoscopic repair offer safe surgery with comparable outcomes for incarcerated inguinal hernia in children.      

Eccrine Spiradenoma

Eccrine spiradenoma is a very rare benign tumor of the skin and subcutaneous tissue originating from the eccrine glands described by Kersting and Helwig in 1956. Eccrine spiradenoma (ES) usually appears as a single bluish/pinkish cystic nodule with size between 0.3 and 5 cm, but in rare occasions can be multiple distributed as a linear form or zosteriform. Generally occurs in young adults age 15 to 35 years and rarely can be found in infants. ES occur mainly in the head, neck and trunk associated with paroxysmal pain and tenderness. It tends to arise on the upper part of the body. It is difficult to differentiate eccrine spiradenoma from other more common lesions and biopsy is necessary to establish a diagnosis. The pathogenesis is thought to be related to differentiation mainly of the secretory coil of eccrine sweat glands. It is important to find epithelial cells, myoepithelial cells and lymphocytes along with void spaces between blood vessels under the microscope for diagnostic confirmation. The presence of myoepithelial cells and phosphorylase demonstrate the eccrine origin of the tumor. ES may be associated with similar tumors of apocrine origin such as trichoblastoma and cylindroma. A few cases of malignant changes in eccrine spiradenoma has been reported very rarely. Malignant changes may occur if the eccrine spiradenoma lasts long enough and clinically shows rapid cystic growth pattern. US study reveals a well-demarcated mass with lobulated contours and does not extend into the musculi-fascial tissues. Management consists of local excision removing the tumor completely to avoid recurrence. In cases of incomplete surgical removal a high risk of local recurrence has been reported. Early and complete surgical excision is curative in most cases.