Abigail E. Martin

The use of intraabdominal tissue expanders as a primary strategy for closure of giant omphaloceles.

BACKGROUND Giant omphaloceles present a unique challenge to pediatric surgeons because of the difficulty in obtaining timely, tension-free closure of tissues over the defect. Reports of the use of tissue expanders in the subcutaneous space, intramuscular space, or intraabdominal cavity have illustrated the usefulness of this technique to provide biologic closure of abdominal wall defects. However, these reports have focused on use of tissue expanders as a second-line treatment after other options, such as silastic silos or attempted primary closure, have failed. METHODS We report 2 cases in which intraabdominal tissue expanders were used as a primary strategy to obtain closure of giant omphalocele defects. CASE REPORTS The first patient was a baby boy born at 36 weeks by date who was prenatally diagnosed with a giant omphalocele. An intraabdominal tissue expander was placed at 2 weeks of age. The tissue expander was removed and his abdomen was primarily closed at 8 weeks of age. The second patient was born at 25 weeks gestation as part of a twin gestation with severe intrauterine growth retardation (600 g birth weight). Bedside reduction was not attempted because of severe pulmonary hypertension and significant loss of abdominal domain because of herniated liver and bowel. At 8 months of age, she underwent laparoscopically assisted placement of an intraabdominal tissue expander. At 9 months of age, the tissue expander was removed, all abdominal viscera were reduced, and the defect was closed using only an 8 x 8-cm piece of AlloDerm (LifeCell, Branchburg, NJ). Both children are currently at home and doing well. CONCLUSIONS We believe that early use of intraabdominal tissue expanders provides a more expedient method of obtaining closure of the defect in giant omphaloceles.

Upregulation of Endogenous Heparin-Binding EGF-Like Growth Factor (HB-EGF) Expression after Intestinal Ischemia/Reperfusion Injury

Expression of endogenous heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF), a proven intestinal cytoprotective molecule, was examined in intestinal epithelial cells (IEC) in vitro, and in intestine undergoing ischemia/reperfusion (I/R) injury in vivo. In vitro, cells were exposed to anoxia for 90 min followed by reoxygenation for 1-3 h (A/R). In vivo, total midgut I/R injury was produced in rats by occlusion of the superior mesenteric artery for 30 or 90 min followed by reperfusion for 4 h. In situ hybridization and immunohistochemistry were used to study HB-EGF mRNA expression and protein production. In vitro, normal IEC had no detectable HB-EGF mRNA or protein expression. After anoxia, cells expressed HB-EGF mRNA and protein, with expression reaching a peak 2-3 h after reoxygenation. In vivo, only very low levels of HB-EGF mRNA and no detectable protein were found in normal intestine. Four hours after I/R, HB-EGF protein was detected in villous epithelia subjected to 30 min but not 90 min of ischemia, whereas HB-EGF mRNA was highly expressed after both ischemic intervals. Endogenous HB-EGF is immediately upregulated in IEC after A/R injury and in intestine after I/R injury. Thus, HB-EGF acts as an immediate early gene under these conditions.

Posterior Reversible Encephalopathy Syndrome Independently Associated With Tacrolimus and Sirolimus After Multivisceral Transplantation

Posterior reversible encephalopathy syndrome (PRES) is a small vessel microangiopathy of the cerebral vasculature that occurs in 0.5–5% of solid organ transplant recipients, most commonly associated with tacrolimus (Tac). Clinical manifestations include hypertension and neurologic symptoms. We report an adult multivisceral transplant recipient who experienced recurrent PRES initially associated with Tac and subsequently with sirolimus. A 49‐year‐old woman with short bowel syndrome underwent multivisceral transplantation due to total parenteral nutrition–related liver disease. She was initially maintained on Tac, mycophenalate mofetil (MMF) and prednisone. Three months after transplantation, she developed renal dysfunction, leading to a reduction in Tac and the addition of sirolimus. Eight months after transplantation, she developed PRES. Tac was discontinued and PRES resolved. Sirolimus was increased to maintain trough levels of 12–15 ng/mL. Fourteen months after transplant, she experienced recurrent PRES which resolved after discontinuing sirolimus. Currently 3 years posttransplant, she is maintained on cyclosporine, MMF and prednisone with no PRES recurrence. In addition to calcineurin inhibitors, sirolimus may also be associated with PRES after solid organ transplantation. Ours is the first report of sirolimus‐associated PRES in the setting of multivisceral transplantation. Identifying a safe alternative immunosuppression regimen was challenging but ultimately successful.

Use of Vascularized Posterior Rectus Sheath Allograft in Pediatric Multivisceral Transplantation - Report of Two Cases

Restoring abdominal wall cover and contour in children undergoing bowel and multivisceral transplantation is often challenging due to discrepancy in size between donor and recipient, poor musculature related to birth defects and loss of abdominal wall integrity from multiple surgeries. A recent innovation is the use of vascularized posterior rectus sheath to enable closure of abdomen. We describe the application of this technique in two pediatric multivisceral transplant recipients—one to buttress a lax abdominal wall in a 22‐month‐old child with megacystis microcolon intestinal hypoperistalsis syndrome and another to accommodate transplanted viscera in a 10‐month child with short bowel secondary to gastoschisis and loss of domain. This is the first successful report of this procedure with long‐term survival. The procedure has potential application to facilitate difficult abdominal closure in both adults and pediatric liver and multivisceral transplantation.

Liver transplantation in an adolescent with acute liver failure from acute lymphoblastic leukemia

The most common identifiable causes of acute liver failure in pediatric patients are infection, drug toxicity, metabolic disease, and autoimmune processes. In many cases, the etiology of acute liver failure cannot be determined. Acute leukemia is an extremely rare cause of acute liver failure, and liver transplantation has traditionally been contraindicated in this setting. We report a case of acute liver failure in a previously healthy 15‐yr‐old male from pre‐B‐cell acute lymphoblastic leukemia. He underwent liver transplantation before the diagnosis was established, and has subsequently received chemotherapy for pre‐B‐cell acute lymphoblastic leukemia. He is currently alive 31 months post‐transplantation. The published literature describing acute lymphoblastic leukemia as a cause of acute liver failure is reviewed.

Congenital Spigelian Hernia and Ipsilateral Cryptorchidism: Raising Awareness Among Urologists

Spigelian hernias (SHs) are rare in the pediatric population. Although pediatric general surgeons often treat this defect, the increased association between a congenital SH and an ipsilateral undescended testis suggests that urologists may be the first provider encountering this entity. Knowledge of this condition is therefore important. We report one such case of a male infant referred to urology for an undescended testicle. Further investigation revealed the testicle to be within a congenital SH sac. Herein, we additionally review the literature concerning SHs associated with ipsilateral undescended testicles.