PEDIATRIC SURGERY UPDATE ©
VOLUME 06, 1996

VOL 06 NO 01 JANUARY 1996

Neonatal Jaundice

Jaundice in newborns is usually physiological, benign, and self-limiting. Persistent conjugated hyperbilirubinemia (greater than 20% of total or 1.5 mg%) must be urgently evaluated. Initial evaluation should include: welltaken history, physical exam, partial and total bilirubin determination, type and blood group, Coombs' test, reticulocyte cell count and a peripheral smear. Cholestasis means a reduction in bile flow in the liver, which depends on the biliary excretion of the conjugated portion. Reduce flow causes progressive damage to hepatic cells. The etiology of the cholestatic infant is classified as infectious, structural, metabolic and systemic. Structurally related etiologies are surgical causes (Biliary atresia). Non-surgical sources are characterized by a sick, low weight infant jaundiced since birth. The diagnostic evaluation of the cholestatic infant should include a series of tests that can exclude perinatal infectious (TORCH titers, hepatitis profile), metabolic (alpha-1-antitrypsin levels), systemic and hereditary causes. Ultrasound of abdomen should be the first diagnostic imaging study done to evaluate the presence of a gallbladder, identify intra or extrahepatic bile ducts dilatation, and liver parenchyma echogenicity. Nuclear studies of bilio-enteric excretion (DISIDA) after pre-stimulation of the microsomal hepatic system with phenobarbital for 3-5 days should follow. Percutaneous liver biopsy and mini-laparotomy may give the final clue toward a structural defect. Diagnostic laparoscopy has recently been found useful in the evaluation of the cholestatic infant.

Recurrent TEF

Esophageal atresia is the most common congenital anomaly of the esophagus. 85% of such newborns also have a tracheo-esophageal fistula (TEF) connecting the distal esophagus with the trachea. Management consists of thoracotomy, closure of the TEF and primary end to end esophago-esophagostomy. The three most common anastomotic complications are in order of frequency: stricture, leakage and recurrent TEF. Recurrent TEF after surgical repair for esophageal atresia occurs in approximately 3-15% of cases. Tension on the anastomoses followed by leakage may lead to local inflammation with breakage of both suture lines enhancing the chance of recurrent TEF. Once established, the fistula allows saliva and food into the trachea, hence clinical suspicion of this diagnosis arises with recurrent respiratory symptoms associated with feedings after repair of esophageal atresia. Diagnosis is confirmed with cineradiography of the esophagus or bronchoscopy. A second thoracotomy is very hazardous, but has proved to be the most effective method to close the recurrent TEF. Either a pleural or pericardial flap will effectively isolate the suture line. Pericardial flap is easier to mobilize, provides sufficient tissue to use and serves as template for ingrowth of new mucosa should leakage occur. Other alternatives are endoscopic diathermy obliteration, laser coagulation, or fibrin glue deposition.

Anal Fissure

Anal fissure is the most common cause of rectal bleeding in the first two years of life. Outstretching of the anal mucocutaneous junction caused by passage of large hard stools during defecation produces a superficial tear of the mucosa in the posterior midline. Pain with the next bowel movement leads to constipation, hardened stools that continue to produce cyclic problems. Large fissures with surrounding bruising should warn against child abuse. Crohn's disease and leukemic infiltration are other conditions to rule-out. The diagnosis is made after inspection of the anal canal. Chronic fissures are associated with hypertrophy of the anal papilla or a distal skin tag. Management is directed toward the associated constipation with stool softeners and anal dilatations, warm perineal baths to relax the internal muscle spasm, and topical analgesics for pain control. If medical therapy fails excision of the fissure with lateral sphincterotomy is performed.

VOL 06 NO 02 FEBRUARY 1996

Cloacal Exstrophy

Cloacal exstrophy is the most severe presentation of a ventral abdominal wall defect. Formerly a fatal disorder it has yield to a higher survival during the past years with improvement in quality of life. The incidence is between one in 200-400,000 live births. Premature rupture of the cloacal membrane before descend of the urorectal septum is the most plausible explanation of the defect. The anomaly consists of a hypogastric omphalocele, two lateral hemibladders joined to a central strip of exstrophied intestinal epithelium (ileocecal plate) through which ileum prolapses, imperforate anus, and ambiguous genitalia (see figure). Other associated anomalies are cardiac, orthopedic (equinovarus), and neurological (tethered cord syndrome, meningocele). Prenatal sonographic diagnosis has been reported. Radiological evaluation should include plain films of chest, spine and ultrasound of urinary tract. Optimal reconstruction centers initially around closure of the omphalocele, approximation of the symphysis pubis (iliac osteotomies may be needed with late repairs), establishment of intestinal continuity preserving all hindgut bowel present with colostomy, and functional closure of the bladder. Infants with rudimentary genitalia are assigned the female gender, early gonadectomy is advised for genetic males. During the preschool years reconstructions focus on urologic (intermittent catheterization) and fecal (pull-through) continence. Vaginal construction will be done later in life.

Burkitt's

Burkitt's lymphoma (BL) is a highly malignant tumor first described during the late 50's in African children (jaw), endemic in nature, and composed of undifferentiated lympho-reticular cells with uniform appearance. The American BL variety is non-endemic, mostly attacks children between 8-12 years of age, predominantly (>75%) with abdominal disease such as unexplained mass, pain, or intussusception. The head and neck region follows. The tumor can appear as a localized, diffuse (multifocal, non-resectable) or metastatic abdominal mass (bone marrow and CNS). It's considered the fastest growing tumor in humans with a doubling time around 12-24 hrs. Chemotherapy is the primary treatment modality due to its effectiveness in rapidly proliferating cells. The role of surgery is to establish the diagnosis (using open biopsy), stage the tumor, remove localized disease, relieve intestinal obstruction and provide vascular access. Complete resection whenever possible offers the patient improved survival. Is more readily accomplished in patients with localized bowel involvement operated on an emergency basis due to acute abdominal symptoms. The only predictor of event free survival is extent of abdominal disease at diagnosis. Debulking (cytoreductive) procedures increases morbidity and delays initiation of chemotherapy worsening prognosis. Extensive tumors should be managed with minimal procedure and immediate chemotherapy (a/o radiotherapy). Bone marrow and CNS involvement are ominous prognostic signs.

Liver FNH

Focal Nodular Hyperplasia (FNH) is a benign liver tumors found in children. Most are female (80%) in their teen or childbearing age, asymptomatic or with non-tender mass on routine exam. Liver function tests are usually normal. Have no malignant potential but should be differentiated by imaging or biopsy from a liver cell adenoma. Is not a life threatening lesion except in women taking oral contraception that may develop hemorrhage. Diagnostic imaging is a CT showing a well circumscribe mass of low density, arteriogram a hypervascular mass, and normal uptake on liver nuclear scan. Laparoscopically guided needle or open biopsy should be done for diagnosis. Histology describes nodular aggregates of normal hepatocytes with areas of intranodular bile duct proliferation. Asymptomatic lesions can be follow-up with ultrasound and resected if they enlarged or become symptomatic. Prognosis is excellent even in tumors left behind.

VOL 06 NO 03 MARCH 1996

SVCS

Superior vena cava syndrome (SVCS), first described by Hunter in 1757, refers to a constellation of signs and symptoms caused by severe reduction in venous return from the head, neck, and upper extremity. The pathogenesis relate to either extraluminal (tumor, mass) or intraluminal (thrombosis) compression of the superior vena cava. The term superior mediastinal syndrome (SMS) is use interchangeably when tracheal compression causing extrinsic respiratory obstruction manifests. In children the most common initial symptom is cough, followed by wheezing, tachypnea, dyspnea, and orthopnea that aggravates lying down (supine) or bending forward. Face, neck and arm swelling may be present. Severity of the SVCS depends on the rapidity of occlusion and collateral vessel development. Most fear complications are cerebral and laryngeal edema or tracheal compression. Non-Hodgkin's mediastinal lymphoma is the leading etiology of SVCS in the pediatric age, followed by cardiac surgery, histoplasmosis mediastinal fibrosis and indwelling venous catheters. CT evaluation estimates the degree of tracheal compression. The strategic approach toward mediastinal tumors causing SVCS/SMS is controversial; the result of the risk of unexpected tracheo-bronchial obstruction during muscle relaxant use. Tissue diagnosis is needed to institute correct therapy. Least invasive diagnostic procedure such as bone marrow aspiration, peripheral lymph node biopsy (IV ketamine with local infiltration), diagnostic thoracentesis (surface marker analysis), or CT guided percutaneous biopsy avoiding profound sedation should be tried first. For open biopsy spontaneous ventilation in sitting position should be preserved, lower extremity IV lines secure, muscle relaxant avoided, if possible, and bronchoscopic instrumentation available.

Chylous Ascites

Chylous ascites (CA) is a rare clinical entity, the result of either intrinsic/extrinsic obstruction of lymphatic drainage or traumatic rupture of lymphatic channels in the mesentery. Chyle leaks through a fistulous tract, exudate through the wall of retroperitoneal lymphatic or from dilated lymphatic in the wall of the bowel or mesentery with proximal obstruction at the base of the mesentery, cisterna chyli or thoracic duct. Characteristically the fluid has: a milky appearance, separates on standing, fat content > 1 gm/dl, total protein > 3 gm/dl, high content of chylomicrons, triglycerides and lymphocytes, and specific gravity above 1.012. Most cases in children are congenital in nature (lymphangiectasia, cystic hygroma of the abdomen, lymphatic dysplasia, etc.). Others have an inflammatory, traumatic, surgical, or neoplastic etiology. Infants are more commonly affected and boys outnumber girls 2:1. CA generally develops insidiously with painless abdominal distension (ascites), weight loss, increase abdominal girth, hypoproteinemia and inanition. Other patients develop acute abdominal symptoms when associated to intestinal obstruction, intussusception or volvulus. Diagnosis relies on the character of the fluid on paracentesis. Lymphangiography can delineate the retroperitoneal lymph pathways but has no direct access to mesenteric or bowel wall lymphatics. Management depends on effective alleviation of etiologic factors. If after extensive work-up the cause is unknown medical therapy using low fat- high protein diet, bed rest, diuretics and repetitive paracentesis should be tried for four weeks. With no improvement, exploratory laparotomy should follow to establish a diagnosis. Sudan III dye given by mouth six hours before surgery helps identify leaking ducts. Intractable ascites have been managed using peritoneo-venous shunting (LeVeen) with mix results. Mortality is related to the specific underlying disease and has been cited as 24% in some series.

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VOL 6 NO 04 APRIL 1996

KTS

The Klippel-Trenaunay Syndrome (KTS) is a congenital angiodysplasia described in 1900 by two French physicians consisting of the following triad: 1) soft tissue and bone hypertrophy with overgrowth of the extremity, 2) hemangiomas a/o lymphangiomas, and 3) venous varicosities. A mesodermal abnormality during fetal development leads to arterio-venous communication in the limb bud producing the resulting KTS. Overgrowth of the unilateral lower extremity is commonly found. Hemangiomas are capillary or port-wine nevus (diffuse telangiectasias of the superficial vessels of the dermis). Pelvic extension of hemangiomas may lead to rectal bleeding or hematuria. Varicosities are atypical, occurring in the lateral extremity aspect due to persistence of embryological (sciatic vein) venous channels. Additional anomalies: syndactylia, spina bifida, and equinovarus. Diagnostic work-up includes roentgenograms to document limb length discrepancy, non-invasive arterio-venous evaluation, venography, and MRI. Management is predominantly conservative such as elastic support for varicosities. Surgery is done selectively for cosmetic reasons, marked leg discrepancy, and complications of the hemangiomas or venous insufficiency.

Morgagni Hernias

First described in 1769, Morgagni Hernias (MH) are rare congenital diaphragmatic defects close to the anterior midline between the costal and sternal origin of the diaphragm. They occur retrosternally in the midline or more commonly on either side (parasternally) of the junction of the embryologic septum transversum and thoracic wall (see the figure) representing less than 2% of all diaphragmatic defects. Almost always asymptomatic, typically present in older children or adults with minimal gastrointestinal symptoms or as incidental finding during routine chest radiography (mass or air-fluid levels). Infants may develop respiratory symptoms (tachypnea, dyspnea and cyanosis) with distress. Cardiac tamponade due to protrusion into the pericardial cavity has been reported. The MH defect contains a sac with liver, small/ large bowel as content. Associated conditions are: heart defects, trisomy 21, omphalocele, and Cantrells' pentalogy. US and CT-Scan can demonstrate the defect. Management is operative. Trans-abdominal subcostal approach is preferred with reduction of the defect and suturing of the diaphragm to undersurface of sternum and posterior rectus sheath. Large defects with phrenic nerve displacement may need a thoracic approach. Results after surgery rely on associated conditions.

GD

Gallbladder Dyskinesia (GD) is uncommonly reported in the pediatric age group. Portrays a motility disorder of the biliary system characterized by poor contractility of the gallbladder causing symptoms similar to those of gallstone disorders, but with a more protracted clinical course. Believed to be caused by spasm of the sphincter of Oddi associated to either a hypersentivity of the gallbladder or hyposensitivity of the sphincter of Oddi to cholecystokinin (CCK). The result is a gallbladder contracting against a closed biliary system. Diagnosis of GD is considered when the ejection fraction of the gallbladder content is less than 35% during a hepatobiliary scan (DISIDA) stimulated with CCK. Twelve children (14%) out of 85 underwent laparoscopic cholecystectomy (LC) at San Pablo Medical Ctr. during a sixty-six-month period for GD. Mean age was 14 years and classic biliary symptoms predominated (RUQ pain and fatty food intolerance). Mean ejection fraction was 16.8%. Pathology specimens showed ten cases with mild to moderate chronic cholecystitis (83%), and two unremarkable. These changes correlated with the mean duration of symptoms. Clinical improvement after surgery was seen in most cases. We believe that LC should be offered to symptomatic children with low ejection fractions if thorough work-up fails to show other GI disorder.

VOL 6 NO 05 MAY 1996

Neuroblastoma

Neuroblastoma (NB) is the most common solid tumor in infants. Originates from the neural crest: sympathetic ganglion chain and adrenal medulla. 75% arise in the retroperitoneum (adrenal gland and paraspinal ganglia), 20% in the posterior mediastinum, and 5% in the neck or pelvis. NB is a solid, highly vascular tumor with a friable pseudocapsule. Most children present with an abdominal mass, and one-fourth have hypertension. Other have: Horner's syndrome, Panda's eyes, anemia, dancing eyes or vaso-intestinal syndrome (VIP). Diagnosis is confirmed with the use of simple X-rays (stipple calcifications), ultrasound, and CT-Scan. Work-up should consider: bone marrow, bone scan, myelogram (if there is evidence of intraspinal extension), and plasma/urine tumor markers level: VMA, HVA, VGA, DOPA. Management depends on stage of disease at diagnosis. Localized tumors receive surgical therapy. Partially resected or unresectable cases need chemotherapy a/o radiotherapy after establishing a histologic diagnosis. Independent variables determining prognosis are age at diagnosis and stage of disease. Young children with stage I/II have a better outcome. Poor outcome for greater stages, older patients, and those with bone cortex metastasis. Other prognostic variables are: site of primary, maturity of tumor, presence of positive lymph nodes, high levels of ferritin, neuron-specific enolase, and diploid DNA.

Duplications

Duplications of the gastrointestinal tract are considered uncommon congenital anomalies usually diagnosed or unexpectedly encountered intraoperatively during the first two years of life. The duplicated bowel can occur anywhere in the GI tract, is attached to the mesenteric border of the native bowel, shares a common wall and blood supply, coated with smooth muscle, and the epithelial lining is GI mucosa. May contain ectopic gastric or pancreatic tissue. Most are saccular, other tubular. Theories on their origin (split notochord syndrome, twining, faulty solid-stage recanalization) do not explain all cases of duplicated bowel. Three-fourth are found in the abdomen (most commonly the ileum and jejunum), 20% in the thorax, the rest thoraco-abdominal or cervical. Symptoms vary according to the size and location of the duplication. Clinical manifestations can range from intestinal obstruction, abdominal pain, GI bleeding, ulceration, or mediastinal compression. Ultrasound confirms the cystic nature of the lesion (muscular rim sign) and CT the relationship to surrounding structures. Management consist of surgical excision avoiding massive loss of normal bowel and removing all bowel suspect of harboring ectopic gastric mucosa.

Ankyloglossia

Inferior ankyloglossia, a condition more commonly known as tongue-tie, is common among infants. It is caused by a thin velum that fixes the tongue to the floor of the mouth. Initially seen in the neonate, it can disappear spontaneously or with sucking if the frenum is sufficiently thin. Other times it will persist causing sucking or swallowing problems, speech disorders or mechanical restriction of tongue movements. Frenulectomy is curative. Indications for frenulectomy are: articulation speech difficulties, mechanical limitations (inability to leak lips, perform intraoral toilet, or play a wind instrument), and problems with either feeding or suction. Should never be done as an office procedure, but at OR under deep mask anesthesia, rapid tongue retraction and electrocoagulation; no sutures are required.

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VOL 6 NO 06 JUNE 1996

Nodular Fasciitis

First reported in 1955 by Konwaler, Nodular fasciitis (NF) is a discrete, reactive pseudosarcomatous proliferation of fibroblasts. This soft tissue fibrous tumor portrays as a rapidly growing, solitary, slightly tender, soft tissue mass (or nodule) dating for 1-2 weeks. Forearm, thigh and upper arm nodules are the most common sites of presentation in young adults. In children, NF originates in the head and neck area between the age of 3 wks and six years (median 18 months). Males and females are equally affected, and lesions reach 0.5 to 9 cm in size. The cranial variety of NF (in the scalp) can cause erosion of the underlying outer table of the skull. Pathologically, NF shows a pattern of delicate fibroblasts in a focal myxoid matrix with areas of hemorrhage, vascular proliferation, and chronic inflammation. Occasional cells with atypical nucleus are found, but mitotic figures are never seen. Management consists of wide local excision of the mass (with local resection or curettage of affected bone). Clinical course is benign, and the lesion shows no aggressive behavior. Recurrences are uncommon, when they occur should question the original pathological diagnosis.

Superior Mesenteric Artery Syndrome

The Superior Mesenteric Artery Syndrome (SMAS), first described by Rokitanski in 1861, is infrequently seen in the pediatric age. Any condition that decreases the angle between the superior mesenteric artery and the aorta resulting in vascular compression of the third portion of the duodenum (nutcracker effect) causes SMAS. Underneath this angle lie three structures: transverse portion of the duodenum, left renal vein, and uncinate process of the pancreas (see the figure). Conditions that predispose to SMAS are: wasting and dietary disorders (anorexia nervosa), severe injury (burns and trauma), deformity of the spine (increased lordosis, spica cast), prolonged bed rest (paraplegia), and the postoperative state. Clinically the patient manifests acute or chronic symptoms of partial high small bowel obstruction: postprandial nausea and bilious vomiting, epigastric discomfort, bloating, weight loss, and relief with side lying or knee-to-chest position. UGIS is diagnostic demonstrating abrupt vertical obstruction of the duodenum with antiperistaltic flow (to and fro) of contrast material. Initial therapy should be conservative lying in prone/ left lateral position postprandially, and naso-jejunal feedings. No improvement may need surgical derotation of the proximal small bowel through the ligament of treitz restoring it to an embryonic position, or bypass procedure (duodeno-jejunostomy).

Laparoscopic Fundoplication

Fundoplication for the management of symptomatic gastroesophageal reflux (GER) is another procedure that has evolved recently taking advantage of minimally invasive technique. Indications for performing either the open or laparoscopic fundoplication are the same, namely: life threatening GER (asthma, cyanotic spells), chronic aspiration syndromes, chronic vomiting with failure to thrive, and reflux induced esophageal stricture. Studies comparing the open versus the laparoscopic technique in the pediatric age have found a reduced mean hospital and postoperative stay with laparoscopy. The lap procedure seems similar to the open regarding efficacy and complication rates. Costs are not excessive, they are even lower if you take into consideration the shorter length of stay. Lower rate of adhesions, pulmonary and wound complications are another benefit of the lap technique suggested. Percutaneous laparoscopic gastrostomy can be done concomitantly for those neurologically impeded children refer with feeding problems and GER. Whether to do a complete (Nissen) or partial (Toupee, Thal, or Boix-Ochoa) wrap relies on the experience of the surgeon with the open procedure. He should continue to do whatever procedure he used to perform using open surgery. Long-terms results of complications or recurrence of GER are still pending publication.