The implication of intestinal bacterial translocation in central line associated blood stream infections in the pediatric population.

INTRODUCTION: Bacterial intestinal translocation plays an important role in neonatal sepsis. We aimed to elucidate the importance of such translocation in causing central line associated blood stream infection (CLABSI) in patients undergoing gastrointestinal surgery (GIS). METHODS: Using a database of pediatric patients with CLABSI, patients were divided into those who had a GI-surgery (where intestines were opened), those who had a non-GI-surgery (NGIS; all other types of surgery) and those who had no surgery (NS). Data regarding type of organisms isolated on culture, their resistance patterns, clearance of CLABSI, type of antibiotic therapy and patient demographics were collected. RESULTS: 117 CLABSIs were identified between 2011 and 2018. 26 patients had GIS, 22 had NGIS and 69 had NS. NS patients were younger. 80% of GIS and NGIS patients had a central line at the time of surgery. Coagulase-negative staphylococcus (CoNS) was the most common organism isolated (32%). CoNS was more common in GIS compared to NGIS and NS (58% vs. 9% vs. 29% respectively, p=0.04). There were no differences in the time to resolution of bacteremia, mortality rates or need to remove the central line. CONCLUSIONS: This information should help inform efforts for prevention of CLABSIs in patients undergoing GI surgery with central lines present. LEVEL OF EVIDENCE: III.

A randomized trial to assess advancement of enteral feedings following surgery for hypertrophic pyloric stenosis.

PURPOSE: The rate of feeding advancement following surgery for hypertrophic pyloric stenosis (HPS) affects length of stay. We hypothesized that: 1) a relaxed feeding regimen following pyloromyotomy would allow infants to achieve feeding goals more quickly without affecting postoperative emesis, and 2) preoperative metabolic derangements would impair the ability to advance feedings following pyloromyotomy. METHODS: A prospective, randomized trial compared two postoperative feeding methods. The primary outcome was length of time to tolerate two consecutive goal feeds (GFs). Infants were randomized into the Incremental-arm (N=74), in which infants were gradually advanced on enteral formula, or the Relaxed-arm (N=69), in which infants were allowed to consume up to GF immediately. Preoperative variables, time to GF, preoperative laboratory values, and postoperative emesis were recorded. A p-value less than 0.05 was significant. RESULTS: Patient demographics, pyloric ultrasound measurements, and episodes of postoperative emesis were similar between groups. Infants in the Relaxed-arm reached GF more quickly than those in the Incremental-arm and had a shorter length of stay (p<0.001). Infants with preoperative serum chloride less than 100mmol/L reached GF more slowly than those with normal labs (p<0.03). CONCLUSION: Following surgery for HPS, surgeons can safely utilize a relaxed, nonstructured feeding regimen, which may allow infants to reach feeding goals more quickly without untoward vomiting. LEVEL OF EVIDENCE: Level 1-therapeutic.

Negative pressure wound therapy for initial management of giant omphalocele.

BACKGROUND: Current treatment of giant omphalocele includes "paint and wait" or placement of mesh or silo. These methods are associated with high complication rates. We propose negative pressure wound therapy as an alternative. METHODS: Patients born between 2009 and 2014 with giant omphalocele were included. Outcomes analyzed were duration of therapy, time to full enteral feeds, treatment related complications, wound surface area over time, type, and time to definitive closure. RESULTS: Eight patients were reviewed. The median duration of therapy was 68 days. Median time to full enteral feeds was 19 days. There were no treatment discontinuations or complications including sac ruptures, wound infections, or fistulas. Wound contraction stopped at 2 months or around 7 cm(2). All surviving patients underwent definitive closure. CONCLUSIONS: Negative pressure wound therapy is a safe and effective treatment for giant omphalocele that allows feeding, has a low complication rate, and is completed in 2 months.

Surgical subinternships: bridging the chiasm between medical school and residency: a position paper prepared by the Subcommittee for Surgery Subinternship and the Curriculum Committee of the Association for Surgical Education.

BACKGROUND: Surgery subinternship rotations are clinical rotations intended to provide senior medical students with experiential exposure and increased autonomy during the care of surgical patients in clinical settings. Due to the lack of guidelines from national surgical organizations, these rotations remain largely unstructured and unstandardized with wide variability in the goals and experiences they provide for medical students. METHODS: Through synthesis of the literature and by applying an iterative process among members of the subcommittee for surgery subinternship and the curriculum committee of the Association for Surgical Education (ASE) consensus recommendations were established. RECOMMENDATIONS: Five defined domains were identified as essential for establishing surgery subinternship rotations. These are: administrative structure, goals and objectives, curricular elements, instructional methods, and assessment tools. CONCLUSIONS: These recommendations should serve as a blue print for establishing a structured, educationally sound, and rewarding clinical rotation for medical students. Applying these recommendations may also provide educators with opportunities for scholarships and academic advancement.

A review of postoperative feeding regimens in infantile hypertrophic pyloric stenosis.

Infantile hypertrophic pyloric stenosis is a condition well known to pediatric surgeons. Postoperative length of hospital stay is a financial concern and remains a potential target for reduction in hospital costs. Ultimately, these costs are directly affected by the ability to effectively advance postoperative enteral nutrition. This review will serve to: 1) identify clinically relevant postoperative feeding patterns following pyloromyotomy, 2) review the relevant literature to determine an optimal feeding pattern, and 3) identify possible preoperative predictors that may determine the success of postoperative feeding regiments.

Prospective determination of percutaneous endoscopic gastrostomy complication rates in children: still a safe procedure.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) placement in children has come under scrutiny with reports of improved safety profiles using laparoscopic-assisted techniques. However, these reports are generally limited by their retrospective nature and the inclusion of historically determined PEG complication rates in children. Complication rates associated with PEG placement in children have not been prospectively studied, and a true modern understanding of the safety profile of PEG when performed in children is unknown. We prospectively followed children undergoing PEG to establish a clear and current understanding of the complication rates associated with this procedure. METHODS: Consecutive PEG procedures performed between December 2009 and August 2010 at a single, tertiary-care pediatric hospital were enrolled for study. Patients were followed prospectively for 90 days with data regarding complications acquired via standardized interviews at 7, 30, and 90 days postoperatively. RESULTS: We enrolled 103 patients for study. Median age and weight at time of operation was 8 months (range, 2 weeks-21 years) and 6.9 kg (range, 2-42). Patients underwent primary placement of either a PEG button (n = 70) or PEG tube (n = 33). There were no intraoperative complications, with a 100% procedure completion rate. Six deaths occurred during this follow-up time period (mean of 37 days postoperatively) and were attributed to causes other than PEG placement. Four patients were lost to follow-up. One PEG tube was electively discontinued before the end of the follow-up period without complication. Of the remaining 92 patients with complete data, 13 complications were observed in 10 patients. Total complication rate was 14%. CONCLUSION: Rates of PEG complications observed in this prospective study are low and are generally minor. Observed rates of PEG-specific complications are lower than historic reports. The safety profile of PEG when performed in today's pediatric population remains comparable in safety to techniques such as laparoscopic-assisted gastrostomy.

Impact of primary omentectomy on longevity of peritoneal dialysis catheters in children.

BACKGROUND: The purpose of this study was to determine the impact of omentectomy on peritoneal dialysis catheter failure rates in pediatric patients with renal failure. METHODS: A retrospective review of children undergoing peritoneal catheter placement was performed over a 22-year period. Children were segregated into those undergoing catheter placements with omentectomy or without. RESULTS: One hundred sixty-three patients were reviewed, with a 1:1.03 ratio of male to female patients. The mean age was 6.25 ± 5.58 years. Fifty-three percent underwent omentectomy. Catheter failure was observed in 63 children (39%). Catheter obstruction was identified in 36%. Peritonitis led to failure in 9.8%. Catheter failure rate was significantly reduced with the performance of omentectomy (23% without omentectomy vs 15% with omentectomy, P = .0054). Differences in time to catheter failure did not reach statistical significance in the omentectomy group (759 vs 280 days, P = .13). CONCLUSIONS: Omentectomy conferred improved utility of peritoneal catheters in children. Omentectomy appears useful in children undergoing peritoneal dialysis catheter placement.

Pericardial effusion and cardiac tamponade associated with central venous catheters in children: an uncommon but serious and treatable condition.

PURPOSE: Pericardial effusion (PCE) resulting in cardiac tamponade (CT) is a rare complication associated with central venous catheters (CVCs) in children. The goal of this study was to determine the demographics, presenting clinical picture and CVC characteristics in children developing CT as a result of a CVC. METHODS: An institutional review board-approved retrospective review of children treated at a tertiary-care pediatric hospital from 1998 to 2007 was conducted. Patients were identified through institutional database search for diagnostic codes of PCE and simultaneously assigned patient codes for the presence of CVC. Patients with incidentally discovered effusions, those with recent cardiac surgery, or those with causative factors other than a CVC were excluded. RESULTS: Over the 10-year study period, 463 patients were identified using the search criteria. Six cases of CVC-associated PCE causing CT were identified (1.3%). Corrected postgestational age at diagnosis ranged from 34 to 41 weeks with a median corrected postgestational age of 38.5 weeks (median, 38.5 weeks). The median time from CVC placement to diagnosis was 2.5 days (range, 0-6 days). Radiographs obtained before diagnosis demonstrated CVC tip to be overlying the cardiac silhouette in 5 patients (83%). Five (83%) of the 6 patients were receiving hyperalimentation via the CVC at the time of PCE. All patients presented with clinical signs of cardiorespiratory distress and/or cardiac arrest. Pericardiocentesis was performed in 5 patients (83%) and resulted in rapid stabilization. All CVCs were removed at diagnosis. There was 1 mortality (17%). CONCLUSIONS: Pericardial effusion and CT associated with CVC is rare and is chiefly a concern among infants. Characteristics of CVCs including infusate and tip position may be associated with increased risk of PCE. This diagnosis should be considered in any infant with a CVC who experiences acute respiratory distress or cardiovascular collapse.

Minimally invasive technique in treatment of complex, subcutaneous abscesses in children.

UNLABELLED: The rising prevalence of community-acquired, methicillin-resistant Staphylococcus aureus (MRSA) has correlated with an escalating number of complex, subcutaneous abscesses in pediatric patients. The purpose of this study was to present a novel technique and early outcome results for the minimally invasive drainage of complex, subcutaneous abscesses. METHODS: Patients' outcomes from the treatment of complex, subcutaneous abscesses were retrospectively reviewed under institutional review board approval from July 2006 to August 2007 at 2 independent, tertiary care pediatric hospitals. Data on patients' demographics, length of hospital stay, and length of treatment were collected, along with analysis of the isolated organisms. The operative technique uses drainage of the abscess through peripheral stab incisions. Cavity debridement and irrigation is followed by placement of a vessel-loop drain through the drainage incisions. Topical wound care without packing is performed twice a day. Drain removal follows resolution of cellulitis and drainage. RESULTS: One hundred twenty-eight patients were treated over a 14-month period. The ratio of females to males was 1.25:1. Average patient age was 51.5 months (median, 21 months) and ranged from 5 weeks to 18 years. The average length of hospital stay was 1.5 days, though 30 patients were treated on an outpatient basis. Methicillin-resistant Staphylococcus aureus was identified in 76% of the cultured specimens. Average length of drain use was 9 days (range, 5-29 days). There were no local recurrences of subcutaneous abscesses. There was no morbidity related to the drainage procedures. CONCLUSION: We present a successful technique for the drainage and treatment of complex abscesses in children with limited, postoperative wound care and no morbidity or recurrence.

Preoperative prediction of need for fundoplication before gastrostomy tube placement in children.

PURPOSE: Percutaneous endoscopic gastrostomy (PEG) tube placement is a common procedure performed for children with oral aspiration and failure to thrive. The concurrent presence of gastroesophageal reflux (GER) may be difficult to diagnose in these children and may dictate the need for an antireflux procedure. The purpose of this study was to review our preoperative evaluation of children undergoing PEG placement to better elucidate preoperative factors that may require eventual fundoplication. METHODS: A retrospective review at a tertiary care, children's hospital between May 2002 and August 2007 was performed of patients undergoing PEG placement. Patients were identified through database search by operative procedure codes. Patient groups were defined as those undergoing PEG alone (group 1) and those requiring fundoplication after prior PEG (group 2). Comparison of patient demographics and radiologic qualitative results of GER was analyzed using chi(2) analysis, with significance determined at P < .05. RESULTS: A total of 863 patients underwent PEG placement over this 64-month period. A sampled cohort of patients undergoing PEG over a year comprised group 1. Forty-four patients (5.1%) underwent Nissen fundoplication after prior PEG placement (group 2). Patient demographics were similar between the groups. Comparison of comorbid conditions and qualitative indicators of GER between the groups showed only cerebral palsy had a significantly higher associated risk of GER that required antireflux surgery. Preoperative clinical assessment had a 95% positive predictive value in identifying children who required only PEG. CONCLUSIONS: Despite the high predictive value of individualized clinical assessment in the ultimate decision for gastrostomy without need of fundoplication, further studies are needed to determine whether children with conditions such as cerebral palsy may require a concurrent antireflux surgery at the time of gastrostomy.

Impact of omphalocele size on associated conditions.

PURPOSE: Omphalocele is often associated with the presence of other congenital anomalies. Case reports have demonstrated nonclassical associations occurring in smaller omphaloceles. The aim of this study was to determine if omphalocele defect size correlates with the type of anomalies found. METHODS: Patient records at a pediatric hospital were retrospectively reviewed for an 8-year period. Data were collected on patient demographics, omphalocele size, and congenital anomalies identified. Size of the abdominal wall defect was determined by either physical examination or operative record of repair. Patient cohorts were designated as those with small (4 cm and less) or large (greater than 4 cm) omphaloceles. RESULTS: Fifty-three cases of omphalocele were observed. Twenty-seven cases were classified as small, with 26 classified as large. A predominance of males was noted in the small omphalocele group (78% vs 42%; P = .01). Intestinal anomalies, including Meckel's diverticulum and intestinal atresia, were only seen in patients with small omphaloceles. Most cardiac anomalies were associated with large omphaloceles (34.6% vs 3.7%; P = .01). CONCLUSION: Small omphalocele size correlates with an increased prevalence of associated gastrointestinal anomalies, a lower prevalence of cardiac anomalies, and a higher predominance of male sex.

Annular pancreas: dramatic differences between children and adults.

BACKGROUND: Annular pancreas is rare; only 737 cases have been reported in the English literature. In addition, no large analysis has compared children and adults. Recently, prenatal diagnosis and advances in imaging have led to increased experience with this condition. STUDY DESIGN: Data from 103 patients (48 children, 55 adults) with annular pancreas, managed from 1992 to 2006, were reviewed. Patients with isolated duodenal atresia, stenosis, or webs were excluded. RESULTS: Median ages at diagnosis were 1 day in children and 47 years in adults. Annular pancreas was more common in girls and women (children, 58%; adults, 69%). Congenital anomalies were more frequent (p < 0.01) in children (71%) than in adults (16%); Down syndrome, cardiac, and intestinal anomalies were most common. Prenatal diagnosis was suspected in 56% of infants, and adults presented with pain (75%), vomiting (24%), pancreatitis (22%), or abnormal liver tests (11%). All children were managed with duodenal bypass. Children were more likely (p < 0.01) to require surgery for associated anomalies. In contrast, adults had fewer duodenal bypass procedures (24%) but more often required endoscopic pancreatobiliary procedures (67%), cholecystectomy (56%), and other pancreatobiliary surgery (20%; p < 0.01). Adults more commonly (p < 0.01) had pancreas divisum (29%) and pancreatobiliary neoplasia (11%). Five children (6%) with multiple anomalies died; all adults survived their operations. Late deaths occurred in 2 children (4%) with multiple anomalies and 3 adults (5%) with pancreatobiliary cancer. CONCLUSIONS: Annular pancreas is associated with a spectrum of disease that differs in children and adults. Congenital anomalies are more common in children with annular pancreas; complex pancreatobiliary disorders and malignancy are more frequent in adults.

Current success in the treatment of intussusception in children.

BACKGROUND: Intussusception remains a common cause of bowel obstruction in young children and results in significant morbidity and mortality if not promptly treated. The goal of this study was to determine the current success rate of radiologic reduction, the requirements for operative intervention, and the effect of delay in presentation on outcome. METHODS: Children treated for intussusception over a 15-year period were reviewed after treatment at a tertiary children's hospital. Records were reviewed for patient outcomes from radiologic evaluation and surgical intervention. RESULTS: Two hundred forty-four children with intussusception were identified. Median age was 8.2 months (range, 16 days to 12.7 years). Eighty-seven percent of patients had ileocolic or ileoileocolic intussusception. The most common presenting symptoms were emesis (81%), hematochezia (61%), and abdominal pain (59%). Contrasted enemas were performed in 190 children, with successful reduction in 46%. Air-contrasted enema reduction was more successful than liquid-contrasted techniques (54% vs 34%; P = .017). Success in reduction was greater if symptom duration was <24 hours compared with >24 hours (59% vs 36%; P = .001). Despite failed prior attempts at reduction, 48% were reduced on reattempted enema reduction. One hundred forty children required surgical intervention for intussusception with 50% requiring bowel resection. Children with symptom duration >24 hours had a greater risk of requiring surgery (73% vs 45%; P < .001) and bowel resection (39% vs 17%; P = .001) than those with symptoms for <24 hours. Pathologic lead points were encountered in 14%. There were 2 deaths and complications occurred in 19%. Length of stay after surgical reduction was 3.9 days, but 6.1 days if bowel resection was required. CONCLUSIONS: Success of intussusception reduction is improved with air-contrasted techniques and is not affected by previously failed, outside attempts. Delay in presentation decreases success in radiologic reduction and increases risk of operative intervention and bowel resection.

Pediatric surgery fellowship compliance to the 80-hour work week.

OBJECTIVE: The goal of this study was to determine the compliance of pediatric surgery fellowships with Accreditation Council for Graduate Medical Education (ACGME) duty hour restrictions while confronting a reduced resident workforce. MATERIALS AND METHODS: An evaluation of training programs was performed by surveying pediatric surgery fellows on aspects of work hours, ACGME guideline compliance, operative case volume, employment of physician extenders, and didactic education. RESULTS: A 74% survey response rate was achieved. Of the respondents, 95% felt fully aware of ACGME guidelines. Although 95% of programs had mechanisms for compliance in place, only 45% of fellows felt compliant. Median work hours were 80 to 90 hours per week. Although subordinate residents were felt to obtain better compliance (>86%), only 69% of fellows perceived greater service commitment as a result. No impact on volume of operative cases was perceived. Of the programs, 89% employed physician extenders and 55% used additional fellows, but no overall effect on fellow work hours was evident. Fellows did not identify an improvement in the quality of clinical fellowships with guideline implementation. CONCLUSIONS: A minority of fellows comply with ACGME guidelines. Vigilance of duty hour tracking correlates to better compliance. A shift of patient care to fellows is perceived. Use of support personnel did not significantly aid compliance.

Gastrointestinal tumors in children and adolescents.

Tumors of the pediatric gastrointestinal tract are extremely rare. Their infrequent presentation at treatment centers has not allowed for the development of standardized treatment protocols and prospective review. The most prevalent gastrointestinal neoplasms and malignancies are described, including gastrointestinal lymphoma, colorectal carcinoma, carcinoid tumors, gastrointestinal stromal tumors, leiomyomas, juvenile polyps, inflammatory pseudotumors, gastric tumors, and Peutz-Jeghers polyposis syndrome. Current recommendations for the medical and surgical management of these tumors are reviewed and summarized for this vast group of gastrointestinal neoplasms in children.

Surgical considerations in cystic fibrosis: a 32-year evaluation of outcomes.

BACKGROUND: Information concerning long-term operative outcomes in patients with cystic fibrosis (CF) is relatively sparse in the operative literature. METHODS: A retrospective review of CF patients with operative conditions was performed (1972-2004) at a tertiary children's hospital to analyze outcomes including long-term morbidity and survival. RESULTS: A total of 226 patients with CF presented with an operative diagnosis (113 men, 113 women). A total of 422 operations were performed in 213 patients (94%). The mean age at operation was 4.1 +/- 6.2 years (range, 1 d to 26 y) and 109 were neonates. Fifteen of 42 (36%) babies with simple meconium ileus (MI) were treated nonoperatively with hypertonic enemas, 27 of 42 and all 45 patients with complicated MI required operation, including 15 with jejunoileal atresia (17%). Seventeen of 27 (63%) patients with meconium ileus equivalent had MI as neonates; 7 of 27 (26%) required operation. Eight of 9 (89%) with fibrosing colonopathy required operation. Organ transplantation was required in 21 patients. Follow-up evaluation was possible in 204 of 213 (96%) patients. The duration of follow-up evaluation was 14.9 +/- 8.5 years (range, 2 mo to 35 y). Operative morbidity was 11% at 1 year, 2% at 2 to 4 years, 1% at 5 to 10 years, and less than 1% at more than 10 years. There were 24 deaths (11%); 22 followed CF-related pulmonary complications and included 8 of 16 (50%) children with pneumothorax. CONCLUSIONS: Long-term survival in CF patients has improved significantly (89%), with many surviving into the fourth decade. MI may predispose to late complications including meconium ileus equivalent and fibrosing colonopathy. Pneumothorax in CF patients is an ominous predictor of mortality. Children with CF are living longer and are good candidates for operation, but require long-term follow-up evaluation because of ongoing exocrine dysfunction.

Supraumbilical pyloromyotomy: a unique indication for antimicrobial prophylaxis.

BACKGROUND: The umbilical fold incision for infantile hypertrophic pyloric stenosis provides a convenient exposure and cosmetically appealing scar. This study investigates the possible difference in infection rates between traditional and supraumbilical approaches for pyloromyotomy. METHODS: All patients who underwent pyloromyotomy for infantile hypertrophic pyloric stenosis at a tertiary pediatric hospital were reviewed. Baseline wound infection rate was determined through review of patients with right upper quadrant incisions (group 1). A nonrandomized comparison was performed between patients with a supraumbilical approach (group 2) and those undergoing supraumbilical incisions after prophylactic antibiotic administration (group 3). RESULTS: Complete records were reviewed on 384 patients over a 6-year period. Demographics and preoperative factors were similar among groups. The rate of infection in group 1 (n = 258) was 2.3%. With introduction of the supraumbilical approach, there was a statistically significant increase in wound infection rate to 7.0% (chi 2 ; group 1 vs group 2, P < .05). The use of prophylactic antibiotics with a supraumbilical approach reduced this rate of infection back to 2.3% (chi 2 ; group 1 vs group 3, P < 1.0 and group 2 [n = 85] vs group 3 [n = 42], P < .3). CONCLUSIONS: The risk of wound infection by classic pyloromyotomy of 2.3% is significantly increased with an open supraumbilical approach. The use of prophylactic antibiotics reduces this risk of wound infection.

Pseudo-Meigs syndrome secondary to ovarian germ cell tumor.

An 11-year-old white girl presenting with fever, dyspnea, and cough demonstrated a left pleural effusion, ascites, and a suprapubic mass on physical and radiologic examinations. Surgical resection of the mass found a stage Ic malignant mixed germ cell tumor of the ovary. The pleural effusion and ascites were benign and resolved spontaneously after complete resection of the tumor, which is characteristic of a pseudo-Meigs syndrome.

The effect of growth hormone supplementation on late nutritional independence in pediatric patients with short bowel syndrome.

PURPOSE: The use of growth hormone (GH) supplementation for intestinal adaptation among adult patients with short bowel syndrome (SBS) has provided mixed results. This report examines the effect of GH supplementation on SBS in pediatric patients. METHODS: Two girls with SBS from neonatal gastrointestinal catastrophes received exogenous GH at 0.3 mg/kg per week subcutaneously and concurrent glutamine supplementation, beginning at 6 and 6(1/2) years of age. Changes in growth (height and weight) and changes in enteral and parenteral energy requirements were evaluated. RESULTS: Treatment duration was 8 and 2.5 years, respectively. Patient weights increased from the 5th to the 41st percentile and from the 17th to the 23rd percentile, respectively. Height increased from the 1st to the 57th percentile in the former patient and increased from less than the 1st to the 17th percentile in the latter. Both patients are independent of parenteral nutrition and take enteral nutrition alone. Tolerance for enteral diets was significantly improved in each girl, with only 2 stools per day maintained in one patient. CONCLUSIONS: The data show that late exogenous treatment with GH and glutamine supplementation improved growth parameters in pediatric patients with SBS. Growth hormone and glutamine supplementation may be beneficial in promoting late intestinal adaptation in pediatric patients with SBS. These data also suggest that these adjuncts may be useful in the early phases of intestinal adaptation.

Novel use of acellular dermal matrix in the formation of a bioprosthetic silo for giant omphalocele coverage.

A case report is presented on the utilization of an acellular dermal matrix in the formation of a biologic silo conducive to early epithelial grafting in the treatment of a giant omphalocele associated with cloacal exstrophy.