Use of polytetrafluoroethylene patch for temporary wound closure after pediatric liver transplantation

Biological abdominal wall expansion in pediatric liver recipients after transplantation with large-for-size organs

BACKGROUND

After pediatric split liver transplantation, intra-abdominal loss of domain due to large-for-size left lateral grafts is a frequent problem for fascial closure and potentially leads to reduced liver perfusion and abdominal compartment syndrome. Therefore, delayed fascial closure with the use of temporary silastic meshes and reoperation or alternative fascial bridging procedures are necessary.

METHODS

Between March 2019 and October 2021, biologic meshes were used for abdominal wall expansion in 6 cases of pediatric split liver transplantation. These cases were analyzed retrospectively.

RESULTS

One male and 5 female children with median age of 6 months (range: 0-57 months) and weight of 6 kg (range: 3.5-22 kg) received a large-for-size left lateral graft. Graft-to-recipient weight ratio (GRWR) was 4.8% (range: 1.5%-8.5%) in median. Biologic mesh implantation for abdominal wall expansion was done in median 7 days (range: 3-11 days) after transplantation when signs of abdominal compartment syndrome with portal vein thrombosis in 3 and of the liver artery in 1 case occurred. In 2 cases, bovine acellular collagen matrix and 4 cases ovine reinforced tissue matrix was used. Median follow-up was 12.5 months (range: 4-28 months) and showed good liver perfusion by sonography and normal corporal development without signs of ventral hernia. One patient died because of fulminant graft rejection and emergency re-transplantation 11 months after the initial transplantation.

CONCLUSIONS

Biologic meshes can be used as safe method for abdominal wall expansion to achieve fascial closure in large-for-size liver transplant recipients. Usage for primary fascial closure can be considered in selected patients.

Long-Term Outcomes of Abdominal Wall Reconstruction with Expanded Polytetrafluoroethylene Mesh in Pediatric Liver Transplantation

Background: Large-for-size syndrome caused by organ size mismatch increases the risk of abdominal compartment syndrome. Massive transfusion and portal vein clamping during liver transplantation may cause abdominal compartment syndrome (ACS) related to mesenteric congestion. In general pediatric surgery—such as correcting gastroschisis—abdominal wall reconstruction for the reparation of defects using expanded polytetrafluoroethylene is an established method. The purpose of this study is to describe the ePTFE-Gore-Tex closure method in patients with or at a high risk of ACS among pediatric liver transplant patients and to investigate the long-term prognosis and outcomes. Methods: From March 1988 to March 2018, 253 pediatric liver transplantation were performed in Seoul National University Hospital. We retrospectively reviewed the cases that underwent abdominal wall reconstruction with ePTFE during liver transplantation. Results: A total of 15 cases underwent abdominal closure with ePTFE-GoreTex graft. We usually used a 2 mm × 10 cm × 15 cm sized Gore-Tex graft for extending the abdominal cavity. The median follow up was 59.5 (17–128.7) months and there were no cases of ACS after transplantation. There were no infectious complications related to ePTFE implantation. The patient and graft survival rate during the study period was 93.3% (14/15). Conclusions: Abdominal wall reconstruction using ePTFE is feasible and could be an alternative option for patients with a high risk of ACS.

Monitoring intra-abdominal pressure after liver transplantation in children

IAH after LTX can impair perfusion and threaten graft viability. This study aimed to assess the feasibility of longitudinal IAP measurements as an IAH screening method in children after LTX. A cohort of 23 children with a mean age (range) 3.1 (3 months-14 years) who underwent LTX between May 2017 and February 2018 were evaluated retrospectively. Longitudinal IAP measurements were compared to bedside Doppler US monitoring data. In total, 425 IAP measurements and 257 US examinations were performed. The mean ± SD (range) time expenditure for IAP measurement was 1.9 ± 0.4 (0.5-3.2) minutes. The mean post-operative IAP was 7.9 ± 3.6 (1-25) mm Hg. IAH (IAP ≥ 10 mm Hg) was noted in 102 (24%) of 257 measurements. Agitation had a significant impact on IAP (estimate: 9.3 mm Hg, CI: 6.72-11.97, P < .01). In patients with TAC, IAP was increased (6.7 ± 2.1 vs 8.7 ± 3.1 mm Hg, P = .02) while peak portal venous velocities decreased (38 ± 27 vs 26 ± 22 cm/s, P = .03) after patch reduction. An abdominal compartment syndrome with severely impaired vascular flow was noted in one patient. Episodes of elevated IAP were noted in a large proportion of patients, underscoring the need for IAP monitoring in pediatric liver transplant recipients. The safety and low time expenditure associated with IAP measurement could be included easily into standard nursing procedures for these patients.

Early Postoperative Acute Kidney Injury Among Pediatric Liver Transplant Recipients

OBJECTIVES

Acute kidney injury after pediatric liver transplant is associated with increased morbidity and mortality. Here, we evaluated children with acute kidney injury early posttransplant using KDIGO criteria to determine incidence, risk factors, and clinical outcomes.

MATERIALS AND METHODS

In this retrospective cohort study, medical records of all patients < 16 years old who underwent liver transplant from April 2007 to April 2017 were reviewed.

RESULTS

Of 117 study patients, 69 (59%) were male and median age at transplant was 72 months (range, 12-120 mo). Forty children (34.2%) had postoperative acute kidney injury, with most having stage 1 disease (n = 21). Compared with children who had acute kidney injury versus those who did not, preoperative activated partial thromboplastin time (median 35.6 s [interquartile range, 32.4-42.8 s] vs 42.5 s [interquartile range, 35-49 s]; P = .007), intraoperative lactate levels at end of surgery (median 5.3 mmol/L [interquartile range, 3.3-8.6 mmol/L] vs 7.9 mmol/L [interquartile range, 4.3-11.2 mmol/L]; P = .044), and need for open abdomen (3% vs 15%; P= .024) were significantly higher. Logistic regression analysis revealed that preoperative high activated partial thromboplastin time (P= .02), intraoperative lactate levels at end of surgery (P = .02), and need for open abdomen (P = .03) were independent risk factors for acute kidney injury. Children who developed acute kidney injury had significantly longer intensive care unit stay (7.1 ± 8.5 vs 4.4 ± 5.4 days, P= .04) and mortality (12.8% vs 1.8%; P = .01).

CONCLUSIONS

Early postoperative acute kidney injury occurred in 34.2% of pediatric liver transplant recipients, with patients having increased mortality risk. High preoperative activated partial throm-boplastin time, high intraoperative end of surgery lactate levels, and need for open abdomen were shown to be associated with acute kidney injury after pediatric liver transplant.

Immediate Tracheal Extubation After Pediatric Liver Transplantation

OBJECTIVES

We examined whether immediate tracheal extubation among pediatric liver transplant recipients was safe and feasible.

MATERIALS AND METHODS

We retrospectively analyzed medical records of pediatric liver transplant recipients at Baskent University Hospital from January 2012 to December 2017. We grouped children who were extubated in the operating room versus those extubated in the intensive care unit.

RESULTS

In our study group of 81 pediatric patients, median age was 4 years (range, 4 mo to 16 y) and 44 (54%) were male. Immediate tracheal extubation in the operating room was performed in 39 patients (48%). Children who remained intubated (n = 42) had more frequent massive hemorrhage (14% vs 0%; P = .015), received larger amounts of packed red blood cells (19.3 vs 10.2 mL/kg; P < .001), and had higher serum lactate levels (9.0 vs 6.9 mmol/L; P = .001) intraoperatively. All children with open abdomens postoperatively remained intubated (n = 7). Patients extubated in the operating room received less vasopressors (1 [3%] vs 12 [29%]; P = .002) and antibiotics (11 [28%] vs 22 [52%]; P = 0.041) and developed infections less frequently postoperatively (3.0 [8%] vs 15.0 [36%]; P = .003). Children extubated in the operating room had shorter mean stay in the intensive care unit (2.0 vs 4.5 days; P < .001). Hospital mortality was higher in children who remained intubated (12% vs 0%; P = .026).

CONCLUSIONS

Immediate tracheal extubation was well tolerated in almost half of our patients and did not compromise their outcomes. Patients who remained intubated had longer intensive care unit stays and higher hospital mortalities. Therefore, we recommend immediate tracheal extubation in the operating room after pediatric liver transplant among those children without intraoperative requirements for massive blood transfusion, high-dose vasopressors, high serum lactate levels, and open abdomen.

Is size the only determinant of delayed abdominal closure in pediatric liver transplant?

The aim was to determine the factors associated with the use of delayed abdominal closure in pediatric liver transplantation (LT) and whether this affected outcome. From a prospectively maintained database, transplants performed in children (≤18 years) were identified (October 2010 to March 2015). Primary abdominal closure was defined as mass closure performed at time of transplant. Delayed abdominal closure was defined as mass closure not initially performed at the same time as transplant; 230 children underwent LT. Of these, 176 (76.5%) had primary closure. Age was similar between the primary and delayed groups (5.0 ± 4.9 versus 3.9 ± 5.0 years; P = 0.13). There was no difference in the graft-to-recipient weight ratio (GRWR) in the primary and delayed groups (3.4 ± 2.8 versus 4.1 ± 2.1; P = 0.12). Children with acute liver failure (ALF) were more likely to experience delayed closure then those with chronic liver disease (CLD; P < 0.001). GRWR was similar between the ALF and CLD (3.4 ± 2.4 versus 3.6 ± 2.7; P = 0.68). Primary closure children had a shorter hospital stay (P < 0.001), spent fewer days in pediatric intensive care unit (PICU; P = 0.001), and required a shorter duration of ventilation (P < 0.001). Vascular complications (arterial and venous) were similar (primary 8.2% versus delayed 5.6%; P = 0.52). Graft (P = 0.42) and child survival (P = 0.65) in the primary and delayed groups were similar. Considering timing of mass closure after transplant, patients in the early delayed closure group (<6 weeks) were found to experience a shorter time of ventilation (P = 0.03) and in PICU (P = 0.003). In conclusion, ALF was the main determinant of delayed abdominal closure rather than GRWR. The optimal time for delayed closure is within 6 weeks. The use of delayed abdominal closure does not adversely affect graft/child survival. Liver Transplantation 23 352-360 2017 AASLD.

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.

Vasospasm shortens cerebral arterial time constant

BACKGROUND

Cerebrovascular time constant (τ) estimates how fast cerebral blood arrives in cerebral arterial bed after each heart stroke. We investigate the pattern of changes in τ following subarachnoid hemorrhage (SAH), with specific emphasis on the temporal profile of changes in relation to the development of cerebral vasospasm.

METHODS

Simultaneous recordings of arterial blood pressure (ABP) and transcranial Doppler (TCD) blood flow velocity (CBFV) in MCA were performed daily in patients after SAH. In 22 patients (10 males and 12 females; median age: 48 years, range: 34-84 years) recordings done before spasm were compared to those done during spasm. Vasospasm was confirmed with TCD (mean CBFV in MCA > 120 cm/s and Lindegaard ratio > 3). τ was estimated as a product of compliance of cerebral arteries (C (a)) and cerebrovascular resistance (CVR). C (a) and CVR were estimated using mathematical transformations of ABP and CBFV waveforms.

RESULTS

Vasospasm caused shortening of τ on both the spastic (before: 0.20 ± 0.05 s vs. spasm: 0.14 ± 0.04 s, P < 0.0008) and contralateral side (before: 0.22 ± 0.05 s vs. spasm: 0.16 ± 0.04 s, P < 0.0008). Before TCD signs of vasospasm were detected, τ demonstrated asymmetry with lower values on ipsilateral side to aneurysm, in comparison to contralateral side (P < 0.009),

CONCLUSIONS

Cerebral vasospasm causes shortening of τ. Shorter τ at the side of aneurysm can be observed before formal TCD signs of vasospasm are observed, therefore, potentially reducing time to escalation of treatment.

Abdominal decompression in children

Abdominal compartment syndrome (ACS) increases the risk for mortality in critically ill children. It occurs in association with a wide variety of medical and surgical diagnoses. Management of ACS involves recognizing the development of intra-abdominal hypertension (IAH) by intra-abdominal pressure (IAP) monitoring, treating the underlying cause, and preventing progression to ACS by lowering IAP. When ACS is already present, supporting dysfunctional organs and decreasing IAP to prevent new organ involvement become an additional focus of therapy. Medical management strategies to achieve these goals should be employed but when medical management fails, timely abdominal decompression is essential to reduce the risk of mortality. A literature review was performed to understand the role and outcomes of abdominal decompression among children with ACS. Abdominal decompression appears to have a positive effect on patient survival. However, prospective randomized studies are needed to fully understand the indications and impact of these therapies on survival in children.

Staged abdominal closure after small bowel or multivisceral transplantation

Following paediatric SBMT, size discrepancy between the recipient's abdomen and the graft may lead to ACS, graft dysfunction, and death. We report our experience with SAC in these patients. Between 04/1993 and 03/2009, 57 children underwent 62 SBMTs. When abdominal wall tension seemed excessive for safe PAC, SAC was performed, using a Silastic® sheet and a vacuum occlusive dressing. Transplantations with SAC (23 combined liver and small bowel [CLB]) were compared with those with PAC [14 ISB and 25 CLB]. Indications for transplantation, preoperative status (after stratification for ISB/CLB transplants), age at transplantation, donor-to-recipient weight ratio, reduction in bowel and/or liver, and incidence of wound complications were not different in both groups. Post-operative intubation, stay in intensive care unit, and hospital stay were prolonged after SAC. Two deaths were related to ACS after PAC, none after SAC. Since 2000, one-yr patient survival is 73% after ISB transplantation and 57% vs. 75% after CLB transplantation with PAC vs. SAC, respectively (NS). SAC safely reduces severe ACS after paediatric SBMT and can be combined with graft reduction for transplantation of small recipients.

Abdominal compartment syndrome associated with capillary leak syndrome after liver transplantation

Orthotopic liver transplantation was performed in a 49-year-old man with metastatic liver sarcoma. After surgery, both abdominal compartment syndrome (ACS) and capillary leak syndrome (CLS) developed. Exploratory laparotomy and colon exteriorization were performed. Five days later, a diagnosis of severe CLS was established, and hydroxyethyl starch was infused to prevent leakage of albumin. The patient gradually recovered over 3 weeks. Awareness of ACS and CLS is important to improve outcome because early diagnosis and immediate therapy are essential. Bladder pressure is a key factor in diagnosing ACS, and pressure of 35 mm Hg is an indication for decompressive laparotomy. During the early stage of CLS, hydroxyethyl starch but not albumin should be used to alleviate edema and hypoalbuminemia.

Pediatric liver transplantation

In previous decades, pediatric liver transplantation has become a state-of-the-art operation with excellent success and limited mortality. Graft and patient survival have continued to improve as a result of improvements in medical, surgical and anesthetic management, organ availability, immunosuppression, and identification and treatment of postoperative complications. The utilization of split-liver grafts and living-related donors has provided more organs for pediatric patients. Newer immunosuppression regimens, including induction therapy, have had a significant impact on graft and patient survival. Future developments of pediatric liver transplantation will deal with long-term follow-up, with prevention of immunosuppression-related complications and promotion of as normal growth as possible. This review describes the state-of-the-art in pediatric liver transplantation.

Incidence and management of abdominal wall defects after intestinal and multivisceral transplantation

BACKGROUND

Successful primary closure of the abdominal wall following visceral organ transplantation is not always feasible. Primary closure under tension can lead to fascial ischemia or necrosis, with subsequent dehiscence. Thus, alternate techniques to achieve abdominal wall closure are an important technical aspect in intestinal transplantation. The authors review their experience managing abdominal wall defects following intestinal or multivisceral transplantation.

METHODS

A retrospective review of the transplant database revealed 28 intestinal transplants in 24 patients from program inception in 1991 to January of 2002. The management of six intestinal transplant recipients with giant posttransplant abdominal wall defects is reviewed, and a novel technique is described for initially managing defects with prosthetic grafts that were serially reduced in size until a clean granulating bed was established, at which time they underwent permanent coverage using a meshed split-thickness skin graft.

RESULTS

Of the 28 transplants, primary fascial closure was possible in only 14. In the other 14 patients, the fascia could not be closed primarily at the time of transplantation. The donor weight-to-recipient weight ratio was significantly greater in patients with abdominal wall closure problems (0.64 versus 1.09; p < 0.005). The incidence of retransplantation was also higher in those with abdominal closure problems compared with those whose fascia could be closed primarily (five of 14 versus one of 14). The six patients managed with skin graft closure did not have any wound complications after grafting.

CONCLUSIONS

Abdominal wall defect after intestinal and multivisceral transplantation is a common problem without an ideal solution. Use of a skin graft on granulating abdominal viscera frozen with adhesions is a simple and reasonable solution to a complex problem.

Temporary silastic mesh closure for adult liver transplantation: a safe alternative for the difficult abdomen

Primary fascial closure is often difficult after adult orthotopic liver transplantation (OLT), complicated by donor-to-recipient graft size mismatch, post-reperfusion hepatic edema, coagulopathy, or intestinal edema. Attempts at closing the abdomen under these circumstances can cause increase in intra-abdominal pressures, resulting in significant complications, including graft loss. Temporary closure with silastic mesh has been used as a viable option in children receiving transplants, but there is no experience recorded with its use in adults. A retrospective review was conducted on 200 consecutive liver transplantations performed over 42 months (October 2002 to February 2006). Records were evaluated for patient and donor demographics, perioperative factors including Model for End-Stage Liver Disease and Child-Turcotte-Pugh scores, indications for OLT, ischemic times, blood product administration, and use of temporary silastic mesh closure. Patients requiring silastic mesh were further evaluated for indication, time to primary fascial closure, duration of intubation, length of stay, graft function, and complications (infectious, vascular, biliary, and hernia development). Comparisons were made with a cohort of patients undergoing OLT over the same time period but who were closed primarily, without the use of temporary silastic mesh. Fifty-one liver transplantations (25.5%) of the 200 total transplant cohort used silastic mesh closure. Comparison of the cohorts (primary closure vs. temporary mesh) revealed that no differences existed, except the requirement of all blood products was significantly greater in the silastic mesh group (P < 0.001). Bowel edema (47.1%) and coagulopathy (37.3%) were the most common indications for mesh closure, with less frequent reasons including donor to recipient size mismatch (11.8%), hemodynamic instability, and a large preexisting fascial defect (2.0% each). The average time from transplant to final fascial closure was 3.4 days (range 2-9 days). In the silastic cohort, 41 transplants where closed primarily, 3 required the addition of synthetic mesh, and 6 had component separation and flap closure. After fascial closure, the mean time to extubation was 1 day. The median length of follow-up was 1.3 years for the silastic closure group. Long-term wound complications in the silastic closure group included 1 instance of colonic fistula, 2 incisional hernias, and 2 wound infections. The 30-day and 1-year patient survival for this group were 93.6 and 82.4%, respectively, and the graft survival for those same periods were 90.2 and 77.7%, respectively. Wound complications, rates of hepatic artery thrombosis or stricture, portal vein thrombosis or stricture, biliary complications, and allograft and patient survival were no different than those in patients undergoing initial primary closure. In adult liver transplantation with a difficult (or potentially difficult) abdomen, temporary closure with silastic mesh was found to allow for uncomplicated fascial closure in a short period of time, with rapid extubation times, excellent graft function, and minimal instances of infectious or wound complications. In circumstances where large amounts of blood products are required, where a size mismatch exists, or where bowel edema is present during adult liver transplantation, temporary closure with silastic mesh is an ideal strategy.

Living donor liver transplantation for biliary atresia: a single-center experience with first 100 cases

The aim of this study is to present our institutional experience in living donor liver transplantation (LDLT) as a treatment for end-stage liver disease in children with biliary atresia (BA). A retrospective review of transplant records was performed. One hundred BA patients (52 males and 48 females) underwent LDLT. The mean follow-up period was 85.5 months. The mean age was 2.4 years. The mean preoperative weight, height, and computed GFR were 12.2 kg, 82.5 cm, and 116.4 ml/min/1.73 m2, respectively. Twenty-seven patients were below 1 year of age, and 49 patients were below 10 kg at the time of transplantation. Ninety-six had had previous Kasai operation prior to transplant. The mean recipient operative time was 628 min. The mean recipient intraoperative blood loss was 176 ml. Thirty-five did not require blood or blood component transfusion. The left lateral segment (64) was the most common type of graft used. There were 27 operative complications which included 3 reoperations for postoperative bleeding, 9 portal vein, 4 hepatic vein, 4 hepatic artery, and 7 biliary complications. There was one in-hospital mortality and one retransplantation. The overall rejection rate was 20%. The overall mortality rate was 3%. The 6-month, 1-year and 5-year actual recipient survival rates were 99%, 98% and 98%, respectively.

Acellular dermal matrix provides a good option for abdominal wall closure following small bowel transplantation: a case report

Following small bowel transplantation (SBTx), approximating the midline abdominal fascia can be problematic in patients with severely retracted abdominal cavities. We first report the use of acellular dermal matrix (ADM) for abdominal closure following living related SBTx. A 44-year-old woman with ultra-short gut syndrome secondary to multiple bowel resections received a 160-cm segmental intestinal graft from her daughter. The graft ileocolic vessels were anastomosed end to side to the inferior vena cava and distal aorta. A terminal ileostomy was fashioned because the patient had previous panproctocolectomy. The graft perfused well, and the laparotomy was primarily closed. On postoperative day 1, the patient required surgical exploration for evacuation of hematoma. Due to graft edema in a significantly retracted abdominal cavity, a 12x7 cm fascia defect was evident. Leaving the abdomen open or using a mesh was not entertained as options due to the high risk of infections. Primary closure under tension would also jeopardize the transplant, increasing the risk of thrombosis. The fascia defect was closed using a segment of ADM. The patient did well and went home on the postoperative day 11. At 2-year follow-up she is well and on oral diet without fascia defect or incisional hernia. This is the first report of the use of ADM for abdominal closure in patients receiving a SBTx. ADM is considered safe when used in contaminated sites and can allow primary closure of difficult wounds often seen in SBTx patients.

Use of a bioengineered skin equivalent for the management of difficult skin defects after pediatric multivisceral transplantation

BACKGROUND

Primary wound closure is not always possible after pediatric multi-visceral transplantation because of oversized donor organs and/or intestinal or graft edema. We report our experience evaluating the safety and efficacy of Graftskin (Apligraf, Organogenesis, Canton, Mass), a bioengineered bi-layered human skin equivalent, for the management of difficult skin abdominal defects after multivisceral transplantation in a pediatric population.

METHODS

A retrospective chart review was performed of pediatric multivisceral transplantation patients who were treated with Graftskin. Adverse events, course of wound reepithelialization, and time for complete closure were recorded.

RESULTS

Four patients, 7 to 29 months old, were treated with Graftskin. One patient died because of unrelated reasons. Stimulation of the granulation, reepithelialization, and rapid reduction of the wound surface and depth occurred in the other 3 patients. Complete reepithelialization occurred within 5 months. No adverse events were noted.

CONCLUSION

Graftskin was a successful treatment for difficult abdominal skin defects after liver and multivisceral transplantation in children.

Abdominal compartment syndrome after liver transplantation

The abdominal compartment syndrome is a well-known complication after abdominal trauma and is increasingly recognized as a potential risk factor for renal failure and mortality after adult orthotopic liver transplantation (OLT). We present a case report of a young patient who presented with acute liver failure complicated by an acute pancreatitis. The patient developed an acute abdominal compartment syndrome after OLT. Transurethral measurement of intraabdominal pressure indicated an abdominal compartment syndrome associated with impaired abdominal vascular perfusion, including liver perfusion. Renal insufficiency was immediately reversed after decompressive bedside laparotomy. The abdominal compartment syndrome is a potential source of posttransplant renal insufficiency and liver necrosis in OLT. It remains, however, a rarely described complication after liver transplantation, despite the presence of significant factors that contribute to elevated intraabdominal pressure.

Use of a silastic silo for closure of the abdominal wall in a pediatric patient receiving a cadaveric split liver

Presented is the successful management of a difficult abdominal wall closure after pediatric liver transplantation. A 5-week-old boy with biliary atresia underwent urgent cadaveric split liver transplantation. The left lateral segment of an adult donor was utilized. Postoperatively, abdominal skin and fascia could not be closed. A SILASTIC (Dow Corning, Midland, MI) silo was applied, and complete closure was possible 6 days later.

Liver transplantation in neonates

Orthotopic liver transplantation (OLT) has evolved over the past two decades to become the standard of care for end-stage liver disease in infants and children. Technical advances, particularly the use of technical variant allografts, have permitted extension of OLT into a much younger and smaller population than previously possible. Major centers around the world now routinely perform OLT in infants with survival success equivalent to that in older children and adults. We are beginning to see a small population of school-aged children who were infant OLT recipients. The further extension of OLT into neonates is more recent, with only a few pediatric centers reporting survival success. Very little is known about this frontier of transplantation. Our intent is to provide an overview of neonatal OLT using all available data and our experience in the field.

Advances in pediatric liver transplantation: continuous monitoring of portal venous and hepatic artery flow with an implantable Doppler probe

BACKGROUND

Acute vascular thrombosis is a dreaded complication in solid organ transplantation. Pediatric liver transplantation is associated with a high incidence of hepatic artery thrombosis. Graft salvage is dependent upon early recognition and correction of the thrombosis. Current methods of surveillance for vascular thrombosis lack early detection.

METHODS

Four consecutive pediatric liver transplantations were performed using the implantable Doppler probe to monitor the patency of the hepatic artery and the portal vein during the early postoperative period.

RESULTS

The implantable Doppler probes provided reliable monitoring of vascular patency. Early detection of hepatic artery thrombosis, with subsequent correction and graft salvage, was achieved with the use of the implantable Doppler probe.

CONCLUSIONS

The implantable Doppler probe provides real-time surveillance of vascular patency for up to 7 days in the postoperative period. Signal quality and character was easily assessed by physician and nursing staff and reliably reflected intravascular flow.

Emergent abdominal decompression with patch abdominoplasty in the pediatric patient

BACKGROUND/PURPOSE

Abdominal compartment syndrome (ACS) is the cardiac, pulmonary, and renal dysfunction that occurs as a result of elevated intraabdominal pressure. The authors present their experience with patch abdominoplasty (PA) in pediatric patients as a means to treat and prevent ACS.

METHODS

The charts of patients who underwent PA were reviewed retrospectively. ACS was defined as the increased oxygen requirements and elevation of peak inspiratory pressures (PIP) associated with abdominal distension and worsening renal and or cardiac function.

RESULTS

A total of 23 patients (13 boys) were treated (average age, 23 months). Diagnoses included necrotizing enterocolitis (NEC, n = 13), trauma (n = 3), Hirschsprung's enterocolitis (n = 2), perforated bowel (n = 4), and bilateral Wilms' tumor with bowel obstruction (n = 1). Oxygen requirements decreased after patch abdominoplasty (mean preoperative FIO2, 0.87 +/- 24, mean postoperative, 0.67 +/- 24 [P = .01]). The PIP decreased significantly in the 13 patients who survived (mean preoperative PIP, 33 +/- 8, mean postoperative PIP, 27 +/- 7 [P = .01]). These PIPs failed to respond in the 8 nonsurvivors (mean preoperative PIP, 35 +/- 10, mean postoperative PIP, 33 +/- 14 [P value not significant]). Six of the 8 nonsurvivors had NEC. Complications of intraabdominal abscess and enterocutaneous fistula were seen in 5 patients, all of who had NEC.

CONCLUSIONS

Patch abdominoplasty effectively decreases airway pressures and oxygen requirements associated with ACS. Complications with PA occur primarily in patients with NEC. Failure to respond with a decrease in PIP and FIO2 requirements is an ominous sign.

Expanded polytetrafluoroethylene entubulation of the rabbit inferior alveolar nerve

OBJECTIVE

The purpose of this study was to evaluate the use of an expanded polytetrafluoroethylene conduit in the treatment of a 6. 0-mm gap in the rabbit inferior alveolar nerve and compare the results with those of an autogenous interpositional tibial nerve graft.

STUDY DESIGN

The inferior alveolar nerves of 5 adult New Zealand White female rabbits (10 nerves) were exposed bilaterally, and a 6-mm segment of each nerve was resected. On one side, chosen at random, the gap was immediately bridged through use of an 8.0 x 2. 0-mm expanded polytetrafluoroethylene conduit; on the other side, the gap was grafted with an autogenous tibial nerve graft. Two randomly selected nerves served as sham-dissected controls. At 15 weeks after surgery, the animals were killed and the entire nerve segments were harvested and prepared according to standard fixation and embedding techniques. The sections were examined histomorphometrically to quantify the degree of axonal regeneration through definition of fascicular number, total fascicular surface area, axonal density, and mean axonal diameter at 3 locations along the repair site.

RESULTS

Light microscopic examination revealed the presence of disorganized neural tissue in both groups, with slightly more fibrovascular interfascicular tissue in the expanded polytetrafluoroethylene group. Histomorphometric analysis revealed no significant differences between groups for most of the measured variables. The mean axonal diameter varied between groups, and the fascicular number was greater in the expanded polytetrafluoroethylene group at the middle site.

CONCLUSIONS

This study demonstrates that regeneration of the inferior alveolar nerve can occur across a 6.0-mm gap through an expanded polytetrafluoroethylene tube with results comparable to those of an autogenous nerve graft, significant donor site morbidity being avoided. The significant differences between groups were probably due to greater containment of regenerating axonal fibers in the expanded polytetrafluoroethylene group.

Pediatric solid organ transplantation

Solid organ transplantation offers hope for long-term survival and more normal lifestyles for children. Many of the procedures used are scaled-down versions of those used in adults and are associated with distinct challenges in children. Recent studies have provided insights into how transplantation can best serve these patients.