PEDIATRIC SURGERY UPDATE ©
VOLUME 08, 1997

VOL 08 NO 01 JANUARY 1997

Sacrococcygeal Dimples

Many newborns are referred to pediatric surgeons because a small pit, hole or sinus is identified over the skin of the sacrococcygeal region. Those located in the coccygeal area (below the intergluteal crease) are usually shallow blind ending dimples with no significance and disappear with growth of the child. Some are deep enough (1 cm) and feces may be caught in them giving the false impression that a fistulous tract is present. On few occasions the contamination may lead to a local infectious process with suppuration. If this situation arises, excision of the dimple is curative. This dimples should not be confused with the more serious situation of a sacral sinus tract (dimple above the intergluteal fold) sometimes associated with an underlying spina bifida occulta. This tract may communicate with the spinal cord and be a source of recurrent episodes of meningitis. An MRI study of the sacral area may help delineate the tract from the skin to the spinal cord structures. Excision at the time of diagnosis should be done by a physician with sound knowledge of neuroanatomy. Dermal sinuses and inclusion tumors may lead to spinal cord tethering and progressive neurologic deterioration.

Sigmoid Volvulus

Sigmoid volvulus is a rare cause of mechanical intestinal obstruction in the pediatric age group. Of all colonic volvulus (cecum, transverse, and sigmoid) this is the most common (~80%). Many reports come from African children. Predisposing conditions are: irregular bowel behavior, consumption of high fiber diet, Hirschsprung's disease, chronic constipation, abnormally long sigmoid flexure, a/o absence of mesosigmoid. The condition arises after clockwise rotation of a redundant sigmoid with a fixed point. Clinically the child presents with abdominal pain of sudden onset over the left lower quadrant, vomiting and obstipation. There may be tenderness, distension, and a palpable mass. Plain abdominal films (classic omega sign) may not yield a diagnosis. Contrast study of the colon (cysto-conray enema) may be diagnostic and therapeutic. Sigmoidoscopy (with tube decompression) can achieve derotation of the bowel. Emergency surgery is needed when there's evidence of strangulation or inability to derotate the volvulus. Sigmoid resection is definitive treatment for children, but nonoperative decompression to allow for elective resection should be attempted in patients with no evidence of peritonitis. The mortality in the acute setting is significant in poor risk patients, the very young, and patients with associated anomalies.

Omphalopagus

Omphalopagus are twins joined through their abdomen and usually sharing liver (hepatic bridge), biliary tree, gastrointestinal, and genitourinary tracts. Conjoined twins occur in one of every 50,000 births. Females predominate and most (two-third) will not survive. Commonly type of conjoined twins reported are in order of frequency: thoraco-omphalopagus, thoracopagus, omphalopagus, parasitic twins and craniopagus. A high incidence of births defects not linked to conjoining (cardiac, neural tube, and orofascial cleft defects) explains the high rate of late mortality in those that survive early separation. Early prenatal diagnosis and assessment of the degree of conjoining provide the couple the option of pregnancy termination, or the physician use of cesarean section to improve survival. Separation is best delayed until the twins are relatively mature and developed (more than six months of age). Emergency separation has been needed with one twin stillborn, with gastroschisis or after development of enterocolitis. Although multiple imaging studies will be required to determine the extent of anatomical union, MRI gives information on hepato-biliary and cardiovascular structures that enable planning a safe separation. Doppler echo can also adequately document the heart status noninvasively avoiding the need for cardiac catheterization.

Ovarian Tumors

Ovarian tumors are uncommon childhood malignancies (1%) characterized by recurrence and resistance to therapy. Aggressive surgery is limited to avoid compromising reproductive capacity and endocrine function. Low incidence and need of mulitinodal therapy encourages referral to centers dealing with effective cancer therapy.The most common histology is germ cell: dysgerminoma, teratoma, and endodermal sinus tumor. This is followed by the sex-cord stroma tumors with a low incidence of malignancy. They can cause feminization (granulosa-theca cell) and masculinization (androblastoma). Other types are: epithelial (older adolescent), lipid-cell, and gonadoblastoma. Ovarian tumors present with acute abdominal symptoms (pain) from impending rupture or torsion. They also cause painless abdominal enlargement, or hormonal changes. Preop work-up should include: human chorionic gonadotropin (HCG) and alpha-fetoprotein ( AFP) levels. Imaging studies: Ultrasound and CT-Scan. The most important prognostic factor in malignant tumors is stage of disease at time of diagnosis. Objectives of surgery are: accurate staging (inspection of peritoneal surfaces and pelvic organs, lymph node evaluation), washing and cytology of peritoneal fluid, tumor removal, and contralateral ovarian biopsy if needed. Chemotherapy consists of: bleomycin, cis-platinum, and vinblastine. Radiotherapy is generally not effective, except in dysgerminoma. Elevation of tumor markers (AFP or HCG) after therapy signals recurrence.
 

Barrett's Esophagus

Barrett's esophagus (BE) refers to replacement of the normal epithelium of the distal 2 to 3 cm of esophagus with metaplastic columnar epithelium containing globet cells. BE is rare (prevalence is increasing) in children. Evolves as a consequence of chronic GE reflux carrying an approximate 40-fold increase in development of malignancy in adult life. Three types of histological epithelium are described in BE: specialized columnar (intestinal metaplasia), junctionaltype (containing mucous glands), and gastric fundustype (containing chief and parietal cells) epithelium. Diagnosis of BE depends on screening endoscopic biopsies in children with reflux before and after treatment. Consequence of reflux in BE are: development of a stricture (junction between metaplastic lining and squamous epithelium), a penetrating ulcer, bleeding, dysplasia or carcinoma-in-situ. Risk factors associated to the development of carcinoma are: length of disease, male sex, smoking history, and intestinal epithelium. Cohorts of children with an increased incidence of BE: mentally retarded, on chemotherapy, cystic fibrosis, after repair of esophageal atresia, and esophageal substitution. Asymptomatic BE children should be managed with acid suppressing medical therapy (omeprazole). Fundoplication should be offered to children with BE based on complications of GE reflux, failed medical therapy, or evidence of alkaline reflux induced BE. Successful antireflux surgery is not followed by regression of the metaplastic mucosa in BE, but can arrest the cephalad progression. Long-term endoscopic surveillance is needed to detect cases of dysplasia or carcinoma before transmural infiltration occurs.
 

Juvenile Polyps

Childhood polyps are usually juvenile (80%). Histology features a cluster of mucoid lobes surrounded by flattened mucussecreting glandular cells (mucous retention polyp), no malignant potential. Commonly seen in children age 310 with a peak at age 56. As a rule only one polyp is present, but occasionally there are two or three almost always confined to the rectal area (within the reach of the finger). Most common complaint is bright painless rectal bleeding. Occasionally the polyp may prolapse through the rectum. Diagnosis is by barium enema, rectal exam, or endoscopy. Removal by endoscopy is the treatment of choice. Rarely colotomy and excision are required.
 

Vol 08 No 03 MARCH 1997

Multiple Endocrine Neoplasia

Multiple endocrine neoplasia (MEN) refers to a familial (autosomic dominant) disorders involving several endocrine glands with hyperplasia or tumor. Two patterns are recognized: MEN 1 which comprises tumors of the pituitary, parathyroid, and pancretic islets and MEN 2 which occurs in two forms: MEN 2A includes medullary carcinoma of the thyroid (MCT), pheochromocytoma and hyperparathyroidism, and MEN 2B with MCT, pheochromocytoma, a marfanoid habitus and neuroma phenotype. The most constant (100%) and life threatening feature of MEN 2 is MCT (usually multicentric and bilateral). Calcitonin is secreted by C cells in abnormally increase amount both in C-cell hyperplasia (precursor of MCT) and MCT. The diagnosis of MCT relies on chemical elevation of basal or stimulated (pentagastrin) calcitonin levels. The MEN 2B gene mutation (exon 16) has been located to a region of chromosome 10 that contains the ret proto-oncogene (same region for the genes for MEN 2A and familial MCT). Direct DNA testing has established the place of prophylactic surgical therapy in this familial cancer syndrome before the development of biochemical or clinical disease. Management for MCT should include total thyroidectomy, and excision of suspicious lymph nodes in the central and lateral compartments of the neck. Thyroidectomy done for elevated chemical marker has a higher rate of curability than when the diagnosis is made clinically (palpable node). After thyroidectomy the child should be yearly followed monitoring plasma levels of calcitonin and carcinoembryonic antigen to detect tumor recurrence, and cathecolamines assays for pheochromocytoma.
 

Neonatal Testicular Torsion

Neonatal testicular torsion (NTT) is a rare condition occurring most commonly during the neonatal period or before birth. The baby presents with a red, swollen scrotum the product of an extra-vaginal torsion of the spermatic cord. The diagnosis (and exclusion of other pathological conditions) is done using color Doppler ultrasound examination revealing lack of intra testicular blood flow on the affected side and normal flow within the contralateral testis (unless the condition arises bilaterally). It has been suggested that the cause of testicular regression syndrome is antenatal torsion of the testis, others belief in vascular injury secondary to birth trauma as the most likely cause. Treatment requires surgical exploration. Controversy exists concerning the timing of exploration as well as the need for contralateral orchiopexy, since some reports suggest that the contralateral testicle is not a risk for torsion. Therapy of the ipsilateral testicle is determined by operative findings. While testicular salvage is nil (subsequent atrophy is the rule), surgical intervention is necessary for any hope of testicular preservation.
 

Intestinal Leiomyosarcomas

Intestinal leiomyosarcomas are very rare gastrointestinal tract (smooth muscle cells) sarcomas in children. Most cases have been diagnosed during the first decade of life, almost 50% in newborns, with a slight female predominance. Microscopic appearance consists of spindle cells with blunt-ended oval nuclei, mitotic figures, anaplasia and bizarre cell forms. Clinically they present with symptoms of intestinal obstruction (intussusception) and/or perforation, other times with abdominal pain or lower GI bleeding They are relatively small, confined and evenly distributed along jejunum, ileum and colon. Therapy consist of radical surgical resection with effort placed on removal of an adequate margin of normal tissue, even if adjacent organs are in consideration. Adjuvant chemotherapy should be considered for lesions with incomplete or questionable margins of resection. Metastasis occurs via the bloodstream and mainly to the lungs. Poor prognosis is associated to high-grade differentiation and inadequate resection, not cytometric DNA ploidy.
 

Vol 8 No 04 APRIL 1997

Bone Marrow Transplant - Central Venous Catheters

Bone marrow transplant (BMT) recipients are an immunocompromised group that needs multiple venous access to meet all the fluid, antibiotic and nutritional requirements during periods of intensive supportive care. All BMT children will have central venous catheters (CVC) inserted before intensive therapy is initiated. CVC are silicone-made multiple lumen catheters (Raaf, Broviac, Hickman, Leonard) inserted in the operating room under local or general anesthesia using the subclavian, external jugular, or internal jugular veins. Main reasons to remove the CVC in BMT are: end of therapy, a complication has developed, or the child dies. Complications can be divided into infectious (local or systemic), mechanical (inability to infuse or withdraw blood, accidental dislodgement, pinch-off syndrome), technical (malfunction), or thrombotic. Infection (20-40%) is the most common reason for early catheter removal in this pancytopenic population. Not all episodes of sepsis results in CVC loss since bacteremias associated with skin flora (coagulase negative staphylococci) are successfully treated with systemic antibiotics. Infections has been associated with preparation, delivery and type of solution infused via the CVC, multiple use of CVC lumens, degree of adherence to strict protocols for IV tubing and dressing changes, properties of the catheters, and host immune status of the child. Tunnel or exit site infections will need catheter removal. Occlusive episodes can be managed with urokinase administration.
 

Neurofibromatosis

Retroperitoneal Teratomas

Retroperitoneal teratoma is infrequent (5% of all teratomas). They are classified as mature, immature or malignant. Most patients are female, younger than six months, and asymptomatic. Clinically they present with increased abdominal girth or weight loss. An abdominal mass is commonly identified, and the presence of a tooth or a definitive bony structure in abdominal films is identified. Ultrasonography and contrast enhanced CT-Scans are of benefit in locating as well as diagnosing abdominal teratoma. Elevated alpha-feto protein level is found in malignant and some immature cases. Surgical excision is curative for the majority of cases since they are loosely attached to surrounding structures. Most children will have benign mature teratoma and show no evidence of recurrence. Retroperitoneal tumors containing high-grade immature elements should be managed with adjuvant chemotherapy.
 

Vol 8 No 05 MAY 1997

Diaphragmatic Eventration

Diaphragmatic eventration (DE) refers to an abnormally high position of part or all of the diaphragm usually associated with a marked decrease in muscle fibers and a membranous appearance of the abnormal area. Etiologically DE is congenital (developmental anomaly characterized by muscular aplasia), or acquired (paralysis due to phrenic nerve injury). Acquired eventration may be associated to use of forceps, breech presentation, tumors, brachial plexus injury, cephalhematoma, thoracic surgery, or clavicular fractures. Anatomically DE may be complete, partial or bilateral. Most children with DE are asymptomatic when incidentally first seen a will not need therapy. Motion of the affected diaphragm may be normal, absent, diminished or paradoxical. Those with symptoms develop acute respiratory distress, difficult feeding, and recurrent pneumonitis the result of decreased pulmonary parenchymal volume. Those whom will need assisted ventilation or cannot be weaned off the ventilator should be plicated. Most authors favor a transthoracic repair (plication) of the DE. Abdominal approach is used for bilateral cases. Plication must be done with sound knowledge of the anatomic distribution of the phrenic nerve. Failure to achieve extubation within a week of plication is an ominous prognostic sign. Late functional results of plication does not interfere with further development of the diaphragm.
 

Neonatal Ovarian Cysts

With the arrival of routine prenatal sonography (US) the number of fetal pelvic-abdominal cystic lesions later confirmed as ovarian cyst has increased. The vast majority of these cysts are unilateral, benign and functional. The pathological cause of these cysts is still unknown, but suggests that there was probably an abnormal stimulation by the mother's human chorionic gonadotropin or abnormal enzyme activity of the theca interna. Most are histologically follicular cysts, lined by granulosa epithelium having a diameter greater than 1 mm on microscopic section. Although mostly asymptomatic, abdominal distension a/o palpable mass is the major clinical feature. Management of ovarian cysts in newborns is dictated by size and ultrasound characteristics (simple or complex). Most small (< 4 cm) simple cysts will involute with time and should be observed with serial ultrasounds to avoid unnecessary operations. Those greater than 5 cm increase their potential for torsion, hemorrhage, or rupture. They can be percutaneously aspirated guided by US or laparoscopy. Recurrent, large, or echo-complex cystic masses may need open surgical removal. If the ovarian tissue is viable, it should be preserved as much as possible after trimming away most of the membrane of the cyst. Infarcted ovarian cysts (chocolate cysts) may need oophorectomy.
 

Esophageal Polyps

Polyps found in the esophagus of a child are extremely rare events. Most are identified in the esophago-gastric junction or distal third of the esophagus during routine esophagogram for gastroesophageal reflux. Polyps associated to reflux and esophagitis are of inflammatory nature and can be managed with either antireflux medication or surgically (fundoplication). Biopsy of the lesion will demonstrate squamous and gastric mucosa with inflammatory infiltrates. Other lesions with a similar radiographic appearance include: varices, foreign bodies, thickening due to esophagitis and true neoplasms. Esophageal squamous papilloma has been reported in children causing intermittent bleeding and vomiting. The pathogenesis of esophageal squamous papilloma is not known, but chronic mucosal irritation and infection with human papilloma virus are most probable mechanisms. Management is either endoscopic or surgical resection.
 

Vol 8 No 06 JUNE 1997

Total Colonic Aganglionosis

Total colonic aganglionosis (TCA) is a variety of what is commonly known as long segment Hirschsprung's disease plagued with delay in diagnosis, higher morbidity/mortality and controversial management. The colon is aganglionic sometimes involving a variable segment of distal ileum. Clinically, infants presents with small bowel obstruction, persistent obstipation, distention, or poor weight gain. Early diagnosis depends on clinical awareness of the condition in neonates with intestinal obstruction, diarrhea, or both. Barium enema changes may easily be passed as unremarkable. Radiographic findings of a shortened colon of normal caliber or the presence of "jejunalization" of the colon suggest TCA in patients with a suggestive history. However, free ileal reflux during the examination with a transition point in the ileum and retention of barium in the entire colon after the examination may be diagnostic. Diagnosis is confirmed by rectal biopsy, and the extent of aganglionosis documented after multiple intestinal biopsies. Management consists of initial enterostomy in the proximally ganglionic bowel (a source of fluid/electrolytes losses, prolonged hospitalization, and nutritional deficiency), followed by a pull-through (Soave or Duhamel) using a  side-to-side anastomosis between a segment of the aganglionic colon to the ganglionated small bowel. The procedure provides a greater surface area for absorption and fecal storage. Diarrhea and distension are temporary after the pull-through, but most patients ultimately tolerate normal feedings.
 

Fibrolamellar Carcinoma

Fibrolamellar carcinoma (FLC) is a rare histologic subtype of hepatocellular carcinoma associated with long-term survival and encapsulation (few mm to 1 cm thick capsule). Occurs almost exclusively in young adolescent women in the absence of cirrhosis, and the serum alpha-fetoprotein is usually normal. Some thinks that it arises in areas of  focal nodular hyperplasia with variable malignant potential. Distinctive histologic features include deeply eosinophilic polygonal hepatocytes and abundant fibrous stroma. Aromatase level are high causing gynecomastia and failure to enter puberty. A defect in chromosome one has been recently identified. Computed tomography remains the most accurate  technique for diagnosis and staging  (large, low attenuation, well-defined edges, some contain areas of calcification or necrosis). The treatment of choice remains radical operation a goal that can be achieved by including partial and total hepatectomy depending on the stage of the tumor. Statistically significant better five year survival rates are observed in patients with solitary tumors and  absent regional lymph node metastases. Cause of death generally is due to a lack of control of the primary tumor. Successful treatment appears to relate to the ability to do a total excision of the primary hepatic tumor.
 

Byler's Disease

Byler's disease is a progressive familial intrahepatic cholestasis liver condition (autosomal recessive) initially seen in infants less than six months of age. Clinically includes jaundice, itching, failure to thrive, and death from liver cirrhosis. Laboratory findings are: elevated levels of bilirubin and aminotransferases, with normal to low levels of GGT and cholesterol. Liver biopsy is non-specific: cholestasis, liver cell plates and ballooning of hepatocytes in central zones. Presumably, the condition could arises from a transport defect that causes retention of bile salts resulting in secondary toxic hepatocyte injury. Some patients respond to medical therapy (UCDA); in other children liver transplant remains standard therapy. Recently, the use of partial bile drainage using cholecystostomy with an interposed jejunal segment to the skin is of advantage in reducing the enterohepatic circulation of bile acids interrupting the natural history of the disease, reducing its complications and preventing the need for early transplantation in many patients.