Techniques for and outcome of liver transplantation in neonates and infants weighing up to 5 kilograms

Large-for-size syndrome prophylaxis in infant liver recipients with low body mass

Transplantation of the left lateral section (LLS) of the liver is now an established practice for treating advanced diffuse and unresectable focal liver diseases in children, with variants of the LLS primarily used in infants. However, the surgical challenge of matching the size of an adult donor's graft to the volume of a child's abdomen remains significant. This review explores historical developments, various approaches to measuring the required functional liver mass, and techniques to prevent complications associated with large-for-size grafts in infants.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (3) postoperative imaging

BACKGROUND

Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of postoperative complications. So far, limited data is available regarding the best radiologic approach to monitor children after liver transplantation.

OBJECTIVE

To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phases. This paper reports the responses related to postoperative imaging.

MATERIALS AND METHODS

An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey.

RESULTS

All sites commence ultrasound (US) monitoring within 24 h after liver transplantation. Monitoring frequency varies across sites, ranging from every 8 h to 72 h in early, and from daily to sporadic use in late postoperative phases. Predefined US protocols are used by 73% of sites. This commonly includes gray scale, color Doppler, and quantitative flow assessment. Alternative flow imaging techniques, contrast-enhanced US, and elastography are applied at 31.8%, 18.2%, and 63.6% of sites, respectively. Computed tomography is performed at 86.4% of sites when clarification is needed. Magnetic resonance imaging is used for selected cases at 36.4% of sites, mainly for assessment of biliary abnormalities or when blood tests are abnormal.

CONCLUSION

Diagnostic imaging is extensively used for postoperative surveillance of children after liver transplantation. While US is generally prioritized, substantial differences were noted in US protocol, timing, and monitoring frequency. The study highlights potential areas for future optimization and standardization of imaging, essential for conducting multicenter studies.

Neonates with acute liver failure have higher overall mortality but similar posttransplant outcomes as older infants

Neonatal acute liver failure (ALF) carries a high mortality rate; however, little data exist on its peritransplant hospital course. This project aimed to identify factors associated with outcomes in neonates with ALF using large multicenter databases. Patients with International Classification of Diseases, Ninth Revision/International Classification of Diseases, Tenth Revision codes for liver failure (2004-2018) from linked Pediatric Health Information System and Scientific Registry of Transplant Recipients databases were assigned to two groups: neonates aged ≤30 days or older infants aged 31-120 days at admission. Billing data were used to assign diagnoses and assess patient comorbidities (sepsis, extracorporeal membrane oxygenation, total parenteral nutrition, intensive care unit, and cardiac/renal/respiratory failure). Statistical analysis included Kaplan-Meier survival curve analysis and univariate and multivariate analyses with the Cox proportional hazards model. We identified 1807 neonates and 890 older infants. Neonates had significantly lower survival to 90 days ( p = 0.04) and a lower rate of liver transplantation (2.0% vs. 6.4%; p < 0.001). Common risk factors associated with death or transplant were present between groups: diagnosis, respiratory failure, cardiac failure, and renal failure. Among neonates versus older infants who received a transplant, there was no significant differences in posttransplant lengths of stay (median 38 vs. 32 days; p = 0.53), posttransplant mortality (15% vs. 11%; p = 0.66), or graft loss (9.7% vs. 8.1%; p = 0.82). We present the largest multicenter study on peritransplant outcomes in neonatal ALF and show similar risk factors for death or transplant in neonates compared with older infants. Despite lower transplantation rates, neonates demonstrate similar posttransplant outcomes as older infants. Further studies are needed to better risk stratify neonates eligible for transplant and improve outcomes.

Large for size in pediatrics liver transplant using left lateral segment grafts: A single center experience

BACKGROUND

There are still controversies in using the large left lateral segment in pediatrics LT, with the possibility of the problem of LFS grafts, and the use of monosegmental or reduced liver grafts in small infants. This study aimed to evaluate our experience with LFSG in pediatrics LT.

METHODS

A cohort retrospective analysis was conducted including pediatric recipients who underwent LT between January 2011 and October 2019. We compared recipients with GRWR ≥ 4% (LFS) vs GRWR < 4% as an average for size grafts.

RESULTS

There were 331 pediatric LT, 74 patients with GRWR ≥ 4%, and 257 patients with GRWR < 4%. In the group of LFS grafts, temporary abdominal closure by silicon patch was done in 39 patients (52.7%), 2 patients (2.7%) had postoperative HAT, 3 patients (4.1%) early PVT, 1 patient (1.3%) bile leak, and 3 patients (4.1%) had wound infection, with no significant difference in these complications between the 2 groups. In patients with LFS- grafts, the 1-, 3-, 5-, and 7-year patients survival rates were 94.6%, 91.7%, 91.7%, and 91.7%, respectively, while the survival rates in patients of the other group were 96.1%, 92.6%, 91.9%, and 91.9%, respectively, with no significant difference (p = .85).

CONCLUSION

Using LFS graft by left lateral segment in pediatric LT with potential delayed abdominal closure is a safe and feasible option with good outcomes and unnecessary need for graft reduction if performed by an experienced multidisciplinary team.

Living donor liver transplantation for small infants aged less than 6 months: The experience of a single institute

PURPOSE

Liver transplantation (LT) for small infants < 6 months old is rare but becoming common as perioperative care improves. In Taiwan, living donor LT (LDLT) has expanded indications but is rarely performed for this age group because of unfavorable outcomes in the literature. We evaluated LDLT outcomes of patients <6 months old.

METHODS

We identified infants < 6 months old undergoing LDLT between 2004 and 2019 at our hospital. Variables related to recipients, donors, surgeries, and outcomes were analyzed.

RESULTS

Nine patients were identified. Indications for LT were biliary atresia (n = 2), Alagille syndrome (n = 1), protein C deficiency (n = 1), and acute liver failure (n = 5), including two patients with neonatal hemochromatosis, one with herpes simplex hepatitis, one with giant cell hepatitis with autoimmune hemolytic anemia, and one with hemophagocytic lymphohistiocytosis. Median age and weight at LT were 129 days and 4.8 kg, respectively. Graft types included left lateral segment (LLS, n = 4), hyper-reduced LLS (n = 4), and monosegment (n = 1). The median graft-to-recipient weight ratio was 4%. The median follow-up period was 14 months (range, 8 days to 127 months) with two mortalities, and two patients were totally weaned off immunosuppressants. Adjuvant therapies were required for patients with giant cell hepatitis and hemophagocytosis. Preoperative reconstructive imaging for estimating graft thickness facilitated surgical planning.

CONCLUSION

Although LDLT is difficult to perform for small infants, outcomes are favorable and mainly dependent on underlying causes in addition to technical innovations.

Risk Factors Affecting Outcomes in Pediatric Liver Transplantation: A Real-World Single-Center Experience

Background

Despite liver transplantation (LT) being the standard treatment for pediatric end-stage liver disease, complications often persist and can adversely affect the post-transplant outcomes. This study aimed to identify the risk factors affecting the outcomes in pediatric LT patients.

Material/Methods

Data from pediatric patients who underwent primary LT from March 1988 to December 2018 were retrospectively analyzed. Chronic liver disease was defined as an explanted liver showing fibrosis regardless of grade, cirrhosis, or any other underlying disease that may cause progressive liver injury leading to fibrosis or cirrhosis.

Results

A total of 255 pediatric patients underwent LT during the study period. Their 1-, 5-, and 10-year overall survival rates were 90.5%, 88.4%, and 87.8%, respectively. According to multivariate analysis, while liver disease without underlying chronic liver disease (P=0.024) and a pediatric end-stage liver disease (PELD) score ≥30 (P=0.036) were the only factors associated with worse survival, body weight <6 kg (P=0.050), whole-liver DDLT compared to LDLT (P=0.001), fulminant liver failure (P=0.008), and postoperative hepatic artery complications (P<0.001) were associated with worse graft survival. Liver disease without underlying chronic liver disease was the only factor independently associated with hepatic artery complications (P=0.003).

Conclusions

Greater caution is recommended in pediatric patients with liver disease unaccompanied by underlying chronic liver disease, high PELD score, or low body weight to improve survival after LT. Hepatic artery complication was the only surgical complication affecting the graft survival outcome, especially in patients having liver disease without underlying chronic liver disease.

Survival and Complication of Liver Transplantation in Infants: A Systematic Review and Meta-Analysis

Background: Modern surgical techniques and scientific advancements have made liver transplant (LT) in infants feasible. However, there are only a small number of studies examining the short- as well as long-term outcomes of LT in this vulnerable subset of children. Methods: Comprehensive searches were done systematically through the PubMed, Scopus, and Google scholar databases. Studies that were retrospective record based or adopted a cohort approach and reported either patient survival rates or graft survival rates or complications of LT in infants were included in the meta-analysis. Statistical analysis was done using STATA version 13.0. Results: A total of 22 studies were included in the meta-analysis. The overall pooled patient survival rate at 1 year, >1-5 years, and >5 years post-transplantation was 85% (95% CI: 78--92%), 71% (95% CI: 59-83%), and 80% (95% CI: 69-91%), respectively. The overall pooled graft survival rate at 1 year, >1-5 years, and >5 years post-transplantation was 72% (95% CI: 68-76%), 62% (95% CI: 46-78%), and 71% (95% CI: 56-86%), respectively. The overall pooled rate for vascular complications, need for re-transplantation, biliary complications, and infection/sepsis was 12% (95% CI: 10-15%), 16% (95% CI: 12-20%), 15% (95% CI: 9-21%), and 50% (95% CI: 38-61%), respectively. Conclusion: The current meta-analysis showed modest patient and graft survival rates for infant liver transplantation. However, the complication rates related to infection/sepsis were high. More comprehensive evidence is required from studies with larger sample sizes and a longer duration of follow-up.

Outcomes of Pediatric Liver Transplantation in Korea Using Two National Registries

BACKGROUND

This retrospective study aimed to evaluate overall survival and the risk factors for mortality among Korean pediatric liver transplantation (LT) patients using data from two national registries: the Korean Network Organ Sharing (KONOS) of the Korea Centers for Disease Control and Prevention and the Korean Organ Transplantation Registry (KOTRY).

METHODS

Prospectively collected data of 755 pediatric patients who underwent primary LT (KONOS, February 2000 to December 2015; KOTRY, May 2014 to December 2017) were retrospectively reviewed.

RESULTS

The 1-, 5-, 10-, and 15-year survival rates were 90.6%, 86.7%, 85.8%, and 85.5%, respectively, in KONOS, and the 1-month, 3-month, 1-year, and 2-year survival rates were 92.1%, 89.4%, 89.4%, and 87.2%, respectively, in KOTRY. There was no significant difference in survival between the two registries. Multivariate analysis identified that body weight ≥6 kg (p <0.001), biliary atresia as underlying liver disease (p = 0.001), and high-volume center (p < 0.001) were associated with better survival according to the KONOS database, while hepatic artery complication (p < 0.001) was associated with poorer overall survival rates according to the KOTRY database.

CONCLUSION

Long-term pediatric patient survival after LT was satisfactory in this Korean national registry analysis. However, children with risk factors for poor outcomes should be carefully managed after LT.

Outcomes of Liver Transplantation in Small Infants

Liver transplantation (LT) for small infants remains challenging because of the demands related to graft selection, surgical technique, and perioperative management. The aim of this study was to evaluate the short-term and longterm outcomes of LT regarding vascular/biliary complications, renal function, growth, and patient/graft survival in infants ≤3 months compared with those of an age between >3 and 6 months at a single transplant center. A total of 64 infants ≤6 months underwent LT and were divided into 2 groups according to age at LT: those of age ≤3 months (range, 6-118 days; XS group, n = 37) and those of age >3 to ≤6 months (range, 124-179 days; S group, n = 27) between 1989 and 2014. Acute liver failure was the main indication for LT in the XS group (n = 31, 84%) versus S (n = 7, 26%). The overall incidence of hepatic artery thrombosis and portal vein thrombosis/stricture were 5.4% and 10.8% in the XS group and 7.4% and 11.1% in the S group, respectively (not significant). The overall incidence of biliary stricture and leakage were 5.4% and 2.7% in the XS group and 3.7% and 3.7% in the S group, respectively (not significant). There was no significant difference between the 2 groups in terms of renal function. No significant difference was found between the 2 groups for each year after LT in terms of height and weight z score. The 1-, 5-, and 10-year patient survival rates were 70.3%, 70.3%, and 70.3% in the XS group compared with 92.6%, 88.9%, and 88.9% in the S group, respectively (not significant). In conclusion, LT for smaller infants has acceptable outcomes despite the challenges of surgical technique, including vascular reconstruction and graft preparation, and perioperative management.

Antithrombotic management and thrombosis rates in children post-liver transplantation: A case series and literature review

Thrombosis is a major postoperative complication in pediatric liver transplantation. There is marked heterogeneity in prophylactic antithrombotic therapies used, without established guidelines. This review summarizes current worldwide incidence of thrombotic events and compares antithrombotic therapies in children post-liver transplant, with comparison to our institution's experience. Of the twenty-three articles with sufficient detail to compare antithrombotic regimens, the overall incidence of thrombosis ranged from 2.4% to 17.3%. Incidence of HAT ranged from 0% to 28.1%, of HVT from 0% to 4.7%, of PVT from 1.5% to 11.2%, and of IVC thrombosis from 0% to 2.8%. Re-transplantation due to thrombosis ranged from 0% to 4.8%. Prophylactic antithrombotic therapies varied between studies, and bleeding complications were infrequently reported. Since 2010, 96 children underwent 100 liver transplants at our institution with thrombosis incidence comparable to international literature (HAT 6%, PVT 5%, IVC 1%, and HVT 0%). Re-transplantation due to thrombosis occurred in 2% and major bleeding occurred in 10%. The prophylactic antithrombotic therapies used post-liver transplantation in children remain varied. Low rates of thrombosis have been reported with antiplatelet use both with and without anticoagulation. Standard definitions and consistent reporting of bleeding complications are required, in addition to thrombosis rates, so that true risk-benefit assessment of reported regimes can be understood.

Urea cycle disorders-update

The urea cycle is a metabolic pathway for the disposal of excess nitrogen, which arises primarily as ammonia. Nitrogen is essential for growth and life-maintenance, but excessive ammonia leads to life-threatening conditions. The urea cycle disorders (UCDs) comprise diseases presenting with hyperammonemia that arise in either the neonatal period (about 50% of cases) or later. Congenital defects of the enzymes or transporters of the urea cycle cause the disease. This cycle utilizes five enzymes, two of which, carbamoylphosphate synthetase 1 and ornithine transcarbamylase are present in the mitochondrial matrix, whereas the others (argininosuccinate synthetase, argininosuccinate lyase and arginase 1) are present in the cytoplasm. In addition, N-acetylglutamate synthase and at least two transporter proteins are essential to urea cycle function. Severity and age of onset depend on residual enzyme or transporter function and are related to the respective gene mutations. The strategy for therapy is to prevent the irreversible toxicity of high-ammonia exposure to the brain. The pathogenesis and natural course are poorly understood because of the rarity of the disease, so an international registry system and novel clinical trials are much needed. We review here the current concepts of the pathogenesis, diagnostics, including genetics and treatment of UCDs.

Aggressive prevention and preemptive management of vascular complications after pediatric liver transplantation: A major impact on graft survival and long-term outcome

Vascular complications are a major cause of patient and graft loss after LTs. The aim of this study was to evaluate the effect of a multimodal perioperative strategy aimed at reducing the incidence of vascular complications. A total of 126 first isolated LTs-performed between November 2008 and December 2015-were retrospectively analyzed. A minimum follow-up period of 24 months was analyzable for 124/126 patients (98.4%). The aggressive preemptive strategy consisted of identifying and immediately managing any problem and any abnormality in the vascular flow, in any of the hepatic vessels, and at any time after the liver graft revascularization. As a result, with a median follow-up of 57 months (3-112 months), not a single graft has been lost from vascular or biliary problems. The actuarial 8-year graft survival is 96.5%. These results have shown that a combination of technical attention, medical prevention, an early diagnosis, and rapid interventions reduced the negative impact of vascular problems on the outcome of both grafts and patients.

Acute liver failure in children-Is living donor liver transplantation justified?

OBJECTIVES

Living donor liver transplantation (LDLT) in patients with acute liver failure (ALF) has become an acceptable alternative to transplantation from deceased donors (DDLT). The aim of this study was to analyze outcomes of LDLT in pediatric patients with ALF based on our center's experience.

MATERIAL AND METHODS

We enrolled 63 children (at our institution) with ALF who underwent liver transplantation between 1997 and 2016. Among them 24 (38%) underwent a LDLT and 39 (62%) received a DDLT. Retrospectively analyzed patient clinical data included: time lapse between qualification for transplantation and transplant surgery, graft characteristics, postoperative complications, long-term results post-transplantation, and living donor morbidity. Overall, we have made a comparison of clinical results between LDLT and DDLT groups.

RESULTS

Follow-up periods ranged from 12 to 182 months (median 109 months) for LDLT patients and 12 to 183 months (median 72 months) for DDLT patients. The median waiting time for a transplant was shorter in LDLT group than in DDLT group. There was not a single case of primary non-function (PNF) in the LDLT group and 20 out of 24 patients (83.3%) had good early graft function; 3 patients (12.5%) in the LDLT group died within 2 months of transplantation but there was no late mortality. In comparison, 4 out of 39 patients (10.2%) had PNF in DDLT group while 20 patients (51.2%) had good early graft function; 8 patients (20.5%) died early within 2 months and 2 patients (5.1%) died late after transplantation. The LDLT group had a shorter cold ischemia time (CIT) of 4 hours in comparison to 9.2 hours in the DDLT group (p<0.0001).

CONCLUSIONS

LDLT is a lifesaving procedure for pediatric patients with ALF. Our experience showed that it may be performed with very good results, and with very low morbidity and no mortality among living donors when performed by experienced teams following strict procedures.

Living donor liver transplantation during the first 3 months of life

Living donor liver transplantation (LDLT) is now an established technique for treating children with end-stage liver disease. Few data exist about liver transplantation (LT) for exclusively young infants, especially infants of <3 months of age. We report our single-center experience with 12 patients in which LDLT was performed during the first 3 months of life and compare the results with those of older infants who underwent LT. All of the patients were treated at the National Center of Child Health and Development, Tokyo, Japan. Between November 2005 to November 2016, 436 children underwent LT. Twelve of these patients underwent LT in the first 3 months of life (median age, 41 days; median weight, 4.0 kg). The indications for transplantation were fulminant hepatic failure (n = 11) and metabolic liver disease (n = 1). All the patients received the left lateral segment (LLS) in situ to mitigate the problem of graft-to-recipient size discrepancy. A reduced LLS graft was used in 11 patients and a segment 2 monosegment graft was used in 1 patient. We compared the results with those of infants who were 4-6 months of age (n = 67) and 7-12 months of age (n = 110) who were treated in the same study period. There were significant differences in the Pediatric End-Stage Liver Disease score and the conversion rate of tacrolimus to cyclosporine in younger infants. Furthermore, the incidence of biliary complications, bloodstream infection, and cytomegalovirus infection tended to be higher, whereas the incidence of acute cellular rejection tended to be lower in younger infants. The overall cumulative 10-year patient and graft survival rates in recipients of <3 months of age were both 90.9%. LDLT during the first 3 months of life appears to be a feasible option with excellent patient and graft survival. Liver Transplantation 23 1051-1057 2017 AASLD.

Outcomes in infants listed for liver transplantation: A retrospective cohort study using the United Network for Organ Sharing database

LT in neonates and young infants can be challenging due to a variety of factors. To describe the waitlist mortality rates and outcomes of patients listed and transplanted as infants identified from the UNOS database. Infants listed for LT between January 1985 and September 2010 were identified from the UNOS database. Mortality on the waitlist as well as outcomes post-LT was compared between infants aged ≤60 days (Group 1), 61-179 days (Group 2), and 180-364 days (Group 3). Of 6763 infants listed for LT (Group 1 n = 496, Group 2 n = 2404, Group 3 n = 3863), mean age at listing was 196 ± 87 days (Group 1, 29 ± 16 days; Group 2, 132 ± 32 days; Group 3, 257 ± 52 days). Waitlist mortality was highest in Group 1 (Group 1 vs. 3 HR 3.01, 95% CI 2.19-4.15, Group 2 vs. Group 3 HR 0.82, 95% CI 0.66-1.03). One- and five-yr graft survival was 59.6% and 42% (Group 1), 66% and 45% (Group 2), and 66.8% and 41% (Group 3) (one-yr survival p = 0.20; five-yr survival p = 0.19). Infants listed for LT at age ≤60 days had greater waitlist mortality risk than older infants. Infants undergoing LT at age ≤60 days had similar rates of patient and graft survival to older infants.

Dorsal approach plus branch patch technique is the preferred method for liver transplanting small babies with monosegmental grafts

PURPOSE

When living donor liver transplantation (LDLT) is performed on small infant patients, the incidence of hepatic artery complications (HACs) is high. Here, we present a retrospective analysis that focuses on our surgical procedure for hepatic arterial reconstruction and the outcomes of monosegmental LDLT.

METHODS

Of the 275 patients who underwent LDLT between May 2001 and December 2015, 13 patients (4.7 %) underwent monosegmental LDLT. Hepatic artery reconstruction was performed under a microscope. The size discrepancy between the graft and the recipient's abdominal cavity was defined as the graft to recipient distance ratio (GRDR) between the left hepatic vein and the portal vein (PV) bifurcation on a preoperative computed tomography scan. HACs were defined as hepatic arterial hypoperfusion.

RESULTS

Recipient hepatic arteries were selected for the branch patch technique in five cases (38.5 %), and the diameter was 2.2 ± 0.6 mm. The anastomotic approaches selected were the dorsal position of the PV in seven cases (53.8 %) and the ventral position in six, and the GRDRs were 2.8 ± 0.4 and 1.9 ± 0.5, respectively (p = 0.012). The incidence rate of HACs caused by external factors, such as compression or inflammation around the anastomotic site, was significantly higher in monosegmental than in non-monosegmental graft recipients (15.4 vs. 1.1 %, p < 0.001).

CONCLUSION

Although monosegmental graft recipients experienced HACs caused by external factors around the anastomotic field, hepatic arterial reconstruction could be safely performed. Important components of successful hepatic arterial reconstructions include the employment of the branch patch technique and the selection of the dorsal approach.

Survival Outcomes Following Pediatric Liver Transplantation (Pedi-SOFT) Score: A Novel Predictive Index

A prognostic index to predict survival after liver transplantation could address several clinical needs. Here, we devised a scoring system that predicts recipient survival after pediatric liver transplantation. We used univariate and multivariate analysis on 4565 pediatric liver transplant recipients data and identified independent recipient and donor risk factors for posttransplant mortality at 3 months. Multiple imputation was used to account for missing variables. We identified five factors as significant predictors of recipient mortality after pediatric liver transplantation: two previous transplants (OR 5.88, CI 2.88-12.01), one previous transplant (OR 2.54, CI 1.75-3.68), life support (OR 3.68, CI 2.39-5.67), renal insufficiency (OR 2.66, CI 1.84-3.84), recipient weight under 6 kilograms (OR 1.67, CI 1.12-2.36) and cadaveric technical variant allograft (OR 1.38, CI 1.03-1.83). The Survival Outcomes Following Pediatric Liver Transplant score assigns weighted risk points to each of these factors in a scoring system to predict 3-month recipient survival after liver transplantation with a C-statistic of 0.74. Although quite accurate when compared with other posttransplant survival models, we would not advocate individual clinical application of the index.

Large-for-size liver transplant: a single-center experience

OBJECTIVES

The ideal ratio between liver transplant graft mass and recipient body weight is unknown, but the graft probably must weigh 0.8% to 2.0% recipient weight. When this ratio > 4%, there may be problems due to large-for-size transplant, especially in recipients < 10 kg. This condition is caused by discrepancy between the small abdominal cavity and large graft and is characterized by decreased blood supply to the liver graft and graft dysfunction. We evaluated our experience with large-for-size grafts.

MATERIALS AND METHODS

We retrospectively evaluated 377 orthotopic liver transplants that were performed from 2001-2014 in our center. We included 188 pediatric transplants in our study.

RESULTS

There were 58 patients < 10 kg who had living-donor living transplant with graft-to-bodyweight ratio > 4%. In 2 patients, the abdomen was closed with a Bogota bag. In 5 patients, reoperation was performed due to vascular problems and abdominal hypertension, and the abdomen was closed with a Bogota bag. All Bogota bags were closed in 2 weeks. After closing the fascia, 10 patients had vascular problems that were diagnosed in the operating room by Doppler ultrasonography, and only the skin was closed without fascia closure. No graft loss occurred due to large-for-size transplant. There were 8 patients who died early after transplant (sepsis, 6 patients; brain death, 2 patients). There was no major donor morbidity or donor mortality.

CONCLUSIONS

Large-for-size graft may cause abdominal compartment syndrome due to the small size of the recipient abdominal cavity, size discrepancies in vascular caliber, insufficient portal circulation, and disturbance of tissue oxygenation. Abdominal closure with a Bogota bag in these patients is safe and effective to avoid abdominal compartment syndrome. Early diagnosis by ultrasonography in the operating room after fascia closure and repeated ultrasonography at the clinic may help avoid graft loss.

Selection of living donor liver grafts for patients weighing 6kg or less

In the field of pediatric living donor liver transplantation (LDLT), physicians sometimes must reduce the volume of left lateral segment (LLS) grafts to prevent large-for-size syndrome. There are 2 established methods for decreasing the size of an LLS graft: the use of a segment 2 (S2) monosegment graft and the use of a reduced LLS graft. However, no procedure for selecting the proper graft type has been established. In this study, we conducted a retrospective investigation of LDLT and examined the strategy of graft selection for patients weighing ≤6 kg. LDLT was conducted 225 times between May 2001 and December 2012, and 15 of the procedures were performed in patients weighing ≤6 kg. We selected S2 monosegment grafts and reduced LLS grafts if the preoperative computed tomography (CT)-volumetry value of the LLS graft was >5% and 4% to 5% of the graft/recipient weight ratio, respectively. We used LLS grafts in 7 recipients, S2 monosegment grafts in 4 recipients, reduced S2 monosegment grafts in 3 recipients, and a reduced LLS graft in 1 recipient. The reduction rate of S2 monosegment grafts for use as LLS grafts was 48.3%. The overall recipient and graft survival rates were both 93.3%, and 1 patient died of a brain hemorrhage. Major surgical complications included hepatic artery thrombosis in 2 recipients, bilioenteric anastomotic strictures in 2 recipients, and portal vein thrombosis in 1 recipient. In conclusion, our graft selection strategy based on preoperative CT-volumetry is highly useful in patients weighing ≤6 kg. S2 monosegment grafts are effective and safe in very small infants particularly neonates.

Recipient body size does not matter in pediatric liver transplantation

BACKGROUND AND PURPOSE

It is controversial whether small size recipient is associated with adverse outcome in liver transplantation. This study aims to evaluate the outcomes of pediatric liver transplantation according to body weight of recipients.

METHODS

Liver transplant recipients (age <18years, from 1993 to 2011) were studied retrospectively. They were categorized according to the body size at the time of transplantation (A: <6kg; B: between 6kg to 10kg; C: >10kg).

RESULTS

A total of 113 patients (83 LDLTs and 30 DDLTs) were studied. Thirteen (11.5%) belonged to group A, 56 (49.6%) belonged to group B, and 44 (38.9%) belonged to group C. The best graft and patient survivals were found in group A (Figs. 1 and 2), and none of the patients required re-laparotomy for general surgical complications, while 32 patients (32%) in groups B and C did. Regarding transplant-related complications, although group A patients had the highest incidence of biliary tract complications (38.5%, n=5), the incidence of vascular complications (hepatic artery: 7%, portal vein: 0%, hepatic vein: 0%) in this group was the lowest among the three groups.

CONCLUSION

Outcomes of small-sized recipients are not inferior. Less technical-related vascular complications, which may lead to early graft loss, were observed. This could be patient-related (less advanced cirrhosis) or surgeon-related (additional attention paid).

Analysis of factors associated with portal vein thrombosis in pediatric living donor liver transplant recipients

The technique of vascular reconstruction plays a major role in the outcome of living donor liver transplantation (LDLT). An increased use of vascular grafts (VGs) as replacements for sclerotic portal veins has become a standard technique for our group. The aim of this study was to analyze the factors associated with portal vein thrombosis (PVT) in pediatric LDLT. We performed a retrospective analysis of 486 primary pediatric LDLT procedures performed between October 1995 and May 2013. VGs used for portal reconstruction included living donor inferior mesenteric veins, living donor ovarian veins, recipient internal jugular veins, deceased donor iliac arteries, and deceased donor iliac veins. Thirty-four patients (7.0%) developed PVT. The incidence of PVT dropped from 10.1% to 2%; the overall utilization of VGs increased from 3.5% to 37.1%. In a multivariate analysis, only the use of VGs remained an independent risk factor for the occurrence of PVT (hazard ratio = 7.2, 95% confidence interval = 2.8-18.7, P < 0.001). There was no difference in survival rates between patients with PVT and patients without PVT. No patient with PVT underwent retransplantation. In conclusion, the use of VGs was independently associated with the development of PVT. Over time, there was a reduction in the incidence of early PVT in this cohort, and there was a trend toward a reduction in total PVT. The occurrence of isolated PVT in this study was not associated with decreased patient or graft survival.

Long term outcomes of pediatric liver transplantation according to age

Liver transplantation (LT) has been the key therapy for end stage liver diseases. However, LT in infancy is still understudied. From 1992 to 2010, 152 children had undergone LT in Seoul National University Hospital. Operations were performed on 43 patients aged less than 12 months (Group A) and 109 patients aged over 12 months (Group B). The mean age of the recipients was 7 months in Group A and 74 months in Group B. The patients' survival rates and post-LT complications were analyzed. The mean Pediatric End-stage Liver Disease score was higher in Group A (21.8) than in Group B (13.4) (P = 0.049). Fulminant hepatitis was less common in Group A (4.8%) than in Group B (13.8%) (P = 0.021). The post-transplant lymphoproliferative disorder and portal vein complication were more common in Group A (14.0%, 18.6%) than in Group B (1.8%, 3.7%) (P = 0.005). However, the 1, 5, and 10 yr patient survival rates were 93%, 93%, and 93%, in Group A and 92%, 90%, and 88% in Group B (P = 0.212). The survival outcome of pediatric LT is excellent and similar regardless of age. LTs in infancy are not riskier than those of children.

Risk factors and treatments for hepatic arterial complications in pediatric living donor liver transplantation

BACKGROUND

Hepatic artery complications (HAC) are a serious complication in pediatric liver transplant recipients because its incidence is high and it can occasionally lead to graft liver failure. We herein present a retrospective analysis of our 10-year experience with pediatric living donor liver transplantation (LDLT) focusing on the risk factors and treatments for HAC.

METHODS

Between May 2001 and November 2011, 209 LDLTs were performed for 203 pediatric recipients. We performed the multivariate analyses to identify the factors associated with HAC and showed the therapeutic strategy and outcome for HAC.

RESULTS

The overall incidence of HAC was 7.2%, and the graft survival of recipients with HAC was 73.3%. The multivariate analysis showed that the pediatric end-stage liver disease score (≥20), post-transplant laparotomy except for HAC treatment and extra-anatomical hepatic artery reconstruction were independent risk factors for HAC (P = 0.020, P = 0.015 and P = 0.002, respectively). Eleven surgical interventions and 13 endovascular interventions were performed for 15 recipients with HAC. The serum aspartate aminotransferase levels pre- and post-treatment for HAC were significantly higher in the surgical group than in the endovascular group (P = 0.016 and P = 0.022, respectively).

CONCLUSIONS

It is important for recipients with risk factors to maintain strict post-transplant management to help prevent HAC and detect it in earlier stages. Endovascular intervention can be a less invasive method for treating HAC than surgical intervention, and can be performed as an early treatment.

Liver graft volumetric changes after living donor liver transplantation with segment 2 graft for small infants

LT for small infants weighing <5 kg with liver failure might require innovative techniques for size reduction and transplantation of small grafts to avoid large-for-size graft, but little is known about post-transplant graft volumetric changes. Five of 172 children who underwent LDLT received monosegment or reduced monosegment grafts using a modified Couinaud's segment II (S2) graft for LDLT. Serial CT was used to evaluate the changes in the GV and other factors before LDLT and one and three months after LDLT. The shape of these grafts was classified into an OL type and an LL type. The GV increased in all patients one month after LDLT, whereas the GV decreased three months after LDLT in OL in comparison with one month after LDLT. The GRWR of the OL type has tended to decrease at three months, whereas the LL type showed a continuous increase with time, but finally they had adapted graft size for their body size. In conclusion, the volume of S2 grafts after LDLT had unique changes toward the ideal volume for the child weight when they received the appropriate liver volume.

Transplantation with hyper-reduced liver grafts in children under 10 kg of weight

BACKGROUND

We had previously described a left lateral segment hyper-reduction technique capable of sizing the graft according to the volume of the abdominal cavity of the recipient.

AIM

The purpose of our study was to evaluate our 14-year live-donor liver transplantation experience with in situ graft hyper-reduction in children under 10 kg of weight.

PATIENTS AND METHODS

Between January 1997 and May 2011, we performed 881 liver transplants. Two hundred and seventy-seven (n = 277) involved pediatric recipients, of which 102 (37 %) were from live donors. Thirty-five (n = 35) patients under 10 kg of weight underwent hyper-reduced living donor liver transplants. There were 21 females (60 %) and 14 males (40 %), with a median age of 12 months (range 3-23) and a median weight of 7.7 kg (range 5.6-10).

RESULTS

Median operative time was 350 min (range 180-510). Median cold ischemia time was 180 min (range 60-300). Twenty-six (n = 26) patients required intraoperative transfusion of blood products. There were 49 postoperative complications involving 26 patients (74 % morbidity rate). One-, 3-, and 5-year survival rates were 87, 79, and 74 %, respectively. Twenty-eight patients are currently alive.

CONCLUSIONS

Hyper-reduced grafts provide an alternative approach for low-weight pediatric recipients. The relatively high immediate postoperative morbidity could be related to the complexity of these patients.

Suggested guidelines for the diagnosis and management of urea cycle disorders

Urea cycle disorders (UCDs) are inborn errors of ammonia detoxification/arginine synthesis due to defects affecting the catalysts of the Krebs-Henseleit cycle (five core enzymes, one activating enzyme and one mitochondrial ornithine/citrulline antiporter) with an estimated incidence of 1:8.000. Patients present with hyperammonemia either shortly after birth (~50%) or, later at any age, leading to death or to severe neurological handicap in many survivors. Despite the existence of effective therapy with alternative pathway therapy and liver transplantation, outcomes remain poor. This may be related to underrecognition and delayed diagnosis due to the nonspecific clinical presentation and insufficient awareness of health care professionals because of disease rarity. These guidelines aim at providing a trans-European consensus to: guide practitioners, set standards of care and help awareness campaigns. To achieve these goals, the guidelines were developed using a Delphi methodology, by having professionals on UCDs across seven European countries to gather all the existing evidence, score it according to the SIGN evidence level system and draw a series of statements supported by an associated level of evidence. The guidelines were revised by external specialist consultants, unrelated authorities in the field of UCDs and practicing pediatricians in training. Although the evidence degree did hardly ever exceed level C (evidence from non-analytical studies like case reports and series), it was sufficient to guide practice on both acute and chronic presentations, address diagnosis, management, monitoring, outcomes, and psychosocial and ethical issues. Also, it identified knowledge voids that must be filled by future research. We believe these guidelines will help to: harmonise practice, set common standards and spread good practices with a positive impact on the outcomes of UCD patients.

Liver transplantation in an African setting

Liver disease in children in the developing world is a frequent occurrence, which is generally inadequately managed because of lack of resources. However, increasingly, there has been a demand for liver transplantation, where primary medical or surgical therapies have failed. The expertise and infrastructure required for a successful outcome are no different from those in more developed countries; if anything, the challenges are greater. Lack of deceased donors because of cultural and religious factors has driven the use of living donors. Short-term survival has generally been good, but long-term outcomes have rarely been reported. In this article, we review the experience of 2 centers at opposite ends of the continent and share our experience of slightly different settings and show that success can be achieved even in resource-reduced environments.

Characterization and outcomes of young infants with acute liver failure

OBJECTIVE

To characterize infants aged ≤ 90 days enrolled in an international, multicenter, prospective registry of children aged < 18 years with acute liver failure (ALF).

STUDY DESIGN

The Pediatric Acute Liver Failure (PALF) Study Group collects prospective data on children from birth to 18 years. We analyzed data from infants aged ≤ 90 days enrolled in the PALF Study before May 18, 2009.

RESULTS

A total of 148 infants were identified in the PALF registry (median age, 18 days). Common etiologies of ALF were indeterminate (38%), neonatal hemochromatosis (13.6%), and herpes simplex virus (12.8%). Spontaneous survival occurred in 60% of the infants, 16% underwent liver transplantation, and 24% died without undergoing liver trsansplantation. Infants with indeterminate ALF were more likely to undergo liver transplantation than those with viral-induced ALF (P = .0002). The cumulative incidence of death without liver transplantation was higher in infants with viral ALF (64%) compared with those with neonatal hemochromatosis (16%) or indeterminate ALF (14%) (P = .0007).

CONCLUSION

ALF in young infants presents unique diagnostic considerations. Spontaneous survival is better than previously thought. Liver transplantation provides an additional option for care.

ABO-incompatible pediatric liver transplantation in very small recipients: Birmingham's experience

Liver transplantation (LT) for very small recipients is challenging but in experienced centres, good results can be achieved. Despite the risk of antibody-mediated acute rejection, some studies have demonstrated the safety of ABO incompatible liver transplantation (ILT) in children and particularly in infants. The aim of our study was to describe the outcome of liver transplantation in infants <5 kg and the safety of using ILT in this group. All LT performed between 1991 and 2010 in children <5 kg were reviewed. Twenty-nine patients were included, five of whom had an ILT. Acute liver failure was encountered in 20 cases. The recipient age and weight at transplantation were respectively 63 days (range: 14-268 days) and 4 kg (range: 2.4-5 kg). The graft-to-recipient ratio was 6.1% (range 2.3-9%). An aortic conduit and delayed abdominal closure were used respectively in 76% and 81% of the procedures. The ABO compatible liver transplantation (CLT) and ILT groups were similar regarding recipient's demographics, graft types or technical transplantation data. The one- and five-yr patient and graft survival were respectively 62%, 62% and 62%, 57.9% with a median follow-up of 95 months. Vascular complications occurred in six cases (21.4%) and biliary complications were encountered in five patients (17%). Acute and chronic rejection developed respectively in 37% and 26% of the recipients. The five patients undergoing ILT are all alive without graft lost after a median follow-up of 34 months (range 7-55 months). When compared with the CLT group, no significant differences were found regarding patient or graft survival, vascular or biliary complications and rejection rates. In our experience, ILT in small infants has short and long term outcomes comparable to ABO-compatible grafts and excellent results can be achieved with a standard immunosuppressive protocol. To avoid mortality on the waiting list for neonatal recipients, ABO-incompatible liver grafts can be used safely.

Liver transplantation in children weighing 5 kg or less: analysis of the UNOS database

LT is a major medical and surgical challenge in very small patients. Aim of the study is to determine the outcomes after LT in infants ≤ 5 kg at transplant in a large cohort of patients.

METHODS

Infants ≤ 5 kg who had LT between 10/1987 and 5/2008 were identified from the UNOS database. Risk factors for death and graft loss were analyzed by multivariate logistic regression.

RESULTS

Of 11,467 children, 570 (5%) were ≤ 5 kg at LT. Mean age and weight at LT were 0.11 ± 0.48 yr, 4.32 ± 0.74 kg, respectively. One- and five-yr patient and graft survival were 77.7%, 72.2% and 66.1%, 57.6%, respectively. The primary cause of death was infection (25.9%). Recipient age was a predictor of graft loss. Patient and graft survival have improved over time. Life support at transplant was identified as a risk factor for both death and graft loss (p < 0.02, p < 0.01, respectively).

CONCLUSION

LT recipients ≤5 kg have high mortality and graft loss. Over time, graft survival has improved, although it is still inferior to the overall reported outcomes of pediatric LT. Being on life support at transplant is a significant risk factor for death and graft loss in very small recipients.

Implications for the usage of the left lateral liver graft for infants ≤10 kg, irrespective of a large-for-size situation--are monosegmental grafts redundant?

Organ donor shortage for infant liver transplant recipients has lead to an increase in splitting and living donation. For cases in which even transplantation of the left lateral graft (Couinaud's segments II + III) results in a "large for size situation" with an estimated graft body weight ratio (GBWR) of >4%, monosegmental liver transplantation was developed. This, however, bears complications because of greater parenchymal surface and suboptimal vascular flow. We exclusively use the left lateral graft from living donors or split grafts. Temporary abdominal closure is attempted in cases of increased pressure. We report of 41 pediatric transplants in 38 children ≤10 kg. Within this group, there were 23 cases with a GBWR of ≥4, and 15 cases with a GBWR <4. There was no statistical difference in vascular or biliary complications. Despite a more frequent rate of temporary abdominal closure, we did not find a higher rate of intra-abdominal infections. Overall, patient and graft survival was excellent in both groups (one death, three re-transplants). We noticed, however, that the ventro-dorsal diameter of the graft appears to be more relevant to potential graft necrosis than the actual graft size. In conclusion, the usage of monosegmental grafts seems unnecessary if transplantation of left lateral grafts is performed by an experienced multidisciplinary team, and temporary abdominal closure is favored in cases of increased abdominal pressure.

Living donor liver transplantation for neonates using segment 2 monosubsegment graft

The prognosis of liver transplantation for neonates with fulminant hepatic failure (FHF) continues to be extremely poor, especially in patients whose body weight is less than 3 kg. To address this problem, we have developed a safe living donor liver transplantation (LDLT) modality for neonates. We performed LDLTs with segment 2 monosubsegment (S2) grafts for three neonatal FHF. The recipient age and body weight at LDLT were 13-27 days, 2.59-2.84 kg, respectively. S2 or reduced S2 grafts (93-98 g) obtained from their fathers were implanted using temporary portacaval shunt. The recipient portal vein was reconstructed at a more distal site, such as the umbilical portion, to have the graft liver move freely during hepatic artery (HA) reconstruction. The recipient operation time and bleeding were 11 h 58 min-15 h 27 min and 200-395 mL, respectively. The graft-to-recipient weight ratio was 3.3-3.8% and primary abdominal wall closure was possible in all cases. Although hepatic artery thrombosis occurred in one case, all cases survived with normal growth. Emergency LDLT with S2 grafts weighing less than 100 g can save neonates with FHF whose body weight is less than 3 kg. This LDLT modality using S2 grafts could become a new option for neonates and very small infants requiring LT.

Reduction of left-lateral segment from living donors for liver transplantation in infants weighing less than 7 kg: technical aspects and outcome

LLS reduction has been frequently used in infants weighing <7 kg. Twenty recipients weighing <7 kg at the time of LDLT, median age 11.0 months and body weight 5.6 kg, were treated with an RLLS (n = 12) or LLS (n = 8) graft. Absolute indication of size reduction was that the estimated GRWR was >4.0%. Even if the preoperative GRWR was <4.0%, the RLLS graft was considered to ensure a size match. A flatfish-type LLS was preferred to a blowfish-type to make an RLLS graft for such a small infantile population. The RLLS recipients had significantly more flatfish-type grafts, while the LLS recipients had more blowfish-type grafts. Primary full-layer wound closure could be performed successfully in all LLS recipients, while in the RLLS group, two patients were forced to have partial skin closure. There were no graft losses related to graft compression. Reducing an LLS is a useful procedure to promote the comfortable accommodation of the graft in an infant weighing <7 kg. Flatfish-type LLS allowed more flexibility to make the suitable volume.

Successful Treatment of Biliary Atresia in Very Small Infants through Living Related Liver Transplantation

Improving outcomes in very small children is a major goal of pediatric liver transplantation. This report describes our experience of living related liver transplantation in an infant weighing 3.98 kg. The recipient, a 80-day-old male infant with congenital biliary atresia, was treated with living donor liver transplantation and then followed up for 6 months. The left lateral segment (segment II, III) with reduced size from the donor, his 26-year-old mother, was used as the graft. The graft weighed 200 g. The graft weight to recipient body weight ratio was 5.025%. The donor regained her liver function within 3 days and was discharged on day 8. The patient showed good results. Liver function returned to normal 9 days after the operation with bilirubin level almost decreased to normal. Cyclosporin, mycophenolate mofetil and prednisone were used for postoperative immunosuppression. No bleeding, thrombosis, infection or bile leakage occurred. The patient had slight fever because of a little collection in the abdomen and recovered after paracentesis and drainage. He was discharged on day 16. The donor and recipient are in satisfactory condition at present. Improvement of technique in hepatic surgery, microsurgical technique in vascular surgery and postoperative intensive care are the keys to ensure the success of the procedure.

Predictors of survival following liver transplantation in infants: a single-center analysis of more than 200 cases

BACKGROUND

Infants (<12 months) who require liver transplantation (LTx) represent a particularly challenging and understudied group of patients.

METHODS

This retrospective study aimed to describe a large single-center experience of infants who received isolated LTx, illustrate important differences in infants versus older children, and identify pretransplant factors which influence survival. More than 25 pre-LTx demographic, laboratory, and operative variables were analyzed using the Log-rank test and Cox proportional hazards model.

RESULTS

Between 1984 and 2006, 216 LTx were performed in 186 infants with a mean follow-up time of 62 months. Median age at LTx was 9 months, the majority had cholestatic liver disease, were hospitalized pre-LTx, and received whole grafts. Leading indications for re-LTx (n=30) included vascular complications (43%) and graft nonfunction (40%), whereas leading causes of death were sepsis and multiorgan failure. One-, 5-, and 10-year graft and patient survivals were 75%/72%/68% and 79%/77%/75%, respectively. Relative to older pediatric recipients, infants had worse overall patient survival (P=0.05). The following were significant univariate predictors of graft loss: age less than 6 months and reduced cadaveric grafts; and of patient loss: age less than 6 months, calculated CrCl less than 90, pre-LTx hospitalization, pre-LTx mechanical ventilation, repeat LTx, infants transplanted for reasons other than cholestatic liver disease, and patients transplanted between 1984 and 1994.

CONCLUSIONS

Long-term outcomes for infants undergoing LTx are excellent and have improved over time. As the largest, single-center analysis of LTx in infants, this study elucidates a unique set of predictors that can aid in medical decision making.

Ammonia toxicity and its prevention in inherited defects of the urea cycle

The urea cycle is the final pathway for removal of surplus nitrogen from the body, and the major route in humans for detoxification of ammonia. The full complement of enzymes is expressed only in liver. Inherited deficiencies of urea cycle enzymes lead to hyperammonaemia, which causes brain damage. Severe defects present with hyperammonaemic crises in neonates. Equally devastating episodes may occur in previously asymptomatic adults with mild defects, most often X-linked ornithine transcarbamylase (OTC) deficiency. Several mechanisms probably contribute to pathogenesis. Treatment aims to reduce plasma ammonia quickly, reduce production of waste nitrogen, dispose of waste nitrogen using alternative pathways to the urea cycle and replace arginine. These therapies have increased survival and probably improve the neurological outcome. Arginine, sodium benzoate, sodium phenylbutyrate and, less often, sodium phenylacetate are used. Long-term correction is achieved by liver transplantation. Gene therapy for OTC deficiency is effective in animals, and work is ongoing to improve persistence and safety.

Emergency liver transplantation in neonates with acute liver failure: long-term follow-up

BACKGROUND

Acute neonatal liver failure is a rare condition that is often fatal. Liver transplantation (LTx) in affected neonates may be life saving, but there are only few data on the long-term outcome of neonatal LTx.

PATIENTS AND METHODS

We conducted a retrospective study of 11 LTx performed in 10 pediatric patients with acute liver failure in the first month of life. Median age at LTx was 15 days (range: 7-31 days) and median weight was 3.25 kg (range: 2-4 kg). The reasons for liver failure were neonatal hemochromatosis (n=5), hemangioendothelioma (n=2), infection caused by echovirus type 11 (n=1), mitochondrial disorder (n=1), unknown (n=1), and primary nonfunction after LTx (n=1). In 10 patients, LTx organs of deceased donors were used (reduced size n=5, split n=5), and living donor LTx was performed in one neonate. The patients were evaluated with respect to survival, graft function, perioperative complications, and neurodevelopmental outcome.

RESULTS

After a median follow-up time of 5 years (range: 1-14 years), 8 of 10 patients (80%) were alive. Seven of them were in good clinical condition and had normal liver function tests. One patient had to undergo retransplantation because of primary nonfunction and another is currently listed for retransplantation because of chronic graft dysfunction. Neurodevelopment was normal in 75% of the surviving patients.

CONCLUSIONS

Liver transplantation provides good short- and medium-term results in neonatal acute liver failure.

Outcomes after liver transplantation in young infants

BACKGROUND

Liver transplantation in infants younger than 90 days is increasingly common. These infants typically arrive for transplantation in fragile medical condition. It is commonly assumed that they may experience high complication rates, difficult postoperative courses, and poor graft and patient survival.

OBJECTIVES

We sought to understand whether graft and patient survival rates in these young infants were lower than in older children, these patients experienced more complications than older children, and health care resource utilization was higher in this population.

PATIENTS AND METHODS

Data queried from the Study of Pediatric Liver Transplantation (SPLIT) database were limited to infants ages 0 to 90 days who had received their primary liver transplant between February 1996 and May 2004. Patients older than 90 days registered in the SPLIT database were used for comparison.

RESULTS

Thirty-eight patients, ages 0 to 90 days, were included in the analysis. Their severity of illness was reflected by a median calculated Pediatric Endstage Liver Disease score of 34.8 at transplant. A majority (89.5%) of infants received cadaveric liver grafts, of which 47% were reduced organs. The infants experienced prolonged hospitalizations, spending an average of 50.9 +/- 7.6 days in the hospital after transplant. Long stays in the intensive care unit (average 22.1 +/- 1.5 days) and need for mechanical ventilation (average 16.2 +/- 2.7 days) also occurred. Length of hospitalization, intensive care, and mechanical ventilation were significantly higher than in older children (P < 0.0001). The reoperation rate (60.5%) was high and significantly greater than in older children (P = 0.007), with 10 patients (26.3%) needing 3 or more early reoperations. Reoperations occurred for bleeding, wound complications, biliary complications, and sepsis. There was no difference in vascular or biliary tract complications compared with older children. Bacterial infections were also common (52.6%) and were seen with greater frequency than in older children (P < 0.04). This infant cohort had an overall graft survival of 76.1% and overall patient survival of 87.8% at 1 year, with median follow-up of 12.5 months (range 0.6-84.0 months). Graft and patient survival in infants younger than 90 days was similar to that in older infants and children (P = NS).

CONCLUSIONS

Young infants experience graft and patient survival similar to that in older cohorts of liver transplant recipients. Posttransplant complication rates, including the reoperation rate, were higher in this younger group, and the duration of hospitalization and intensive support were significantly longer. Future studies to better examine the factors, including age, that may contribute to the need for reoperation in children are warranted. Recognition and further analysis of the cost of care in this age group is also needed.

The reduced left lateral segment in pediatric liver transplantation: an alternative to the monosegment graft

Tailoring graft size to small paediatric recipients is a challenge. We have developed a reduced left lateral segment as an alternative to monosegment transplantation for small size recipients. Since November 2000, 89 children have been transplanted with 100 deceased donor liver grafts in our unit. Our median patient and graft survival is 89% and 88% respectively. Four of these cases were performed using a new technique of creating a small donor graft by reducing the left lateral segment. The median weight of the reduced liver graft was 264 g (range: 165-390 g). The median blood transfusion requirement was 101 mL/kg body weight (range 69-167 mL/kg). The median values of peak ALT were 1473 IU/L, INR 2.2 and bilirubin 293 micromol/L in the first two wk following surgery. One neonatal recipient died five days after transplantation from a massive intracranial haemorrhage despite satisfactory graft function. Another recipient with excellent graft function died 10 months later from primary pulmonary hypertension and secondary cardiac failure. Hepatic artery thrombosis occurred in one patient with successful revascularization but he was retransplanted three months later for chronic rejection. No biliary or venous outflow complications occurred in this group. This technique of reduced left lateral segment liver transplantation is an alternative to the monosegment graft and allows small recipients to be successfully transplanted with few technical complications related to graft preparation.

Living donor liver transplantation for acute liver failure in infants: the impact of unknown etiology

Infants with ALF occasionally have the most urgent need for a liver transplant. In urgent situations for liver transplantation, LDLT has been advocated. Between July 1995 and April 2004, medical records of 15 infants undergoing LDLT for ALF of unknown etiology were reviewed and their outcomes were compared with infants undergoing LDLT for other liver diseases. They received LLS (n = 9), MS (n = 3), and RMS (n = 3) grafts. Eight technical complications occurred, with a similar incidence for LDLT and the other liver diseases. On the other hand, the liver biopsies after LDLT showed a significantly higher incidence of ACR with centrilobular injuries. Ten patients died after primary LDLT because of refractory rejection (n = 6), rotavirus infection (n = 2), chronic rejection (n = 1), and surgical complications (n = 1). With a median follow-up of 7.0 months, five-yr graft and patient survival rates were 17.8% and 26.7%, respectively. In conclusion, the outcome of LDLT for ALF in infants, especially cases with unknown etiology, was unsatisfactory and refractory rejection often led to liver failure. From our observation the centrilobular changes were characteristics of ACR in infantile LDLT for cryptogenic ALF.

Living donor liver transplantation for children in Brazil weighing less than 10 kilograms

Infants with end-stage liver disease represent a treatment challenge. Living donor liver transplantation (LDLT) is the only option for timely liver transplantation in many areas of the world, adding to the technical difficulties of the procedure. Factors that affect morbidity and mortality can now be determined, which opens a new era for improvement. We have accumulated an 11-year experience with LDLT for children weighing<10 kg. From October 1995 to October 2006, a total of 222 LDLT in patients<18 years of age were performed; 129 primary LDLT and 7 retransplants (4 LDLT and 3 deceased donor grafts) were performed in 129 infants weighing<10 kg. Forty-seven patients received grafts with graft-to-recipient weight ratio (GRWR) of >4%. Two patients received monosegmental grafts, and 2 patients underwent delayed abdominal wall closure. Portal vein thrombosis occurred in 5.4% of the patients, hepatic artery thrombosis in 3.1%, and both in 1.5%. Among several variables studied, only the bilirubin level at the time of transplantation was associated with increased risk of death (P=0.009). Grafts with GRWR>4% had no negative effect on patient survival. There were 7 retransplants, and 4 patients received a second parental LDLT. Patient survival rates at 1, 3, and 10 years after transplantation were 88.8%, 84.7%, and 82% for all children, and 87.5%, 84.9%, and 84.9% for infants weighing<10 kg. LDLT has results comparable to other modalities of liver transplantation in infants. Monosegment grafts were rarely required in this series, although they may be necessary in patients with lower body weight.

Comparison between allogenic and autologous vascular conduits in the drainage of anterior sector in right living donor liver transplantation

Congestion of the anterior sector may lead to graft failure in right lobe grafts. Selective drainage of the prominent segment 5 and/or 8 veins is proposed to overcome this problem. Different vascular conduits may be used during drainage of the anterior sector. In this study, we evaluated the efficiency of the vascular conduits. Between June 1999 and December 2005, 190 patients underwent living donor right lobe liver transplantation and reconstruction of segment 5 and/or 8 veins was performed in 48 patients (25.2%). Two groups were formed according to the types of vascular conduits. Cryopreserved cadaveric iliac artery (n = 28) and cryopreserved cadaveric iliac vein (n = 8) were used in group A. In group B, recipient saphenous vein (n = 6), recipient umbilical vein (n = 5) and recipient collateral omental vein (n = 1) were used for reconstruction. The graft-recipient weight ratio, mean duration of anhepatic phase and MELD scores between two groups were not significantly different. All of the conduits were found to be patent just after reperfusion and in the early postoperative period by Doppler ultrasonography. In follow-up period of 1 year, four (11%) patients died in group A, two patients (16%) in group B. One of these patients died because of sepsis started from the saphenous vein incision site. None of the patients dying in the two groups were lost due to venous outflow problems. This study proves the efficacy of drainage of segment 5 and/or 8 veins using cryopreserved cadaveric vascular conduits. Every effort should be employed to store cadaveric iliac vessels, otherwise, whole other additive surgical intervention to ensure vascular conduit may lead uninvited serious complication.

Biliary atresia: interdisciplinary initiatives focus on a rare disease

During the last decade, biliary atresia (BA) has attained more interest and the frequency of BA-related publications has increased continuously. Pediatric hepatologists and pediatric surgeons are very active in improving diagnosis and treatment modalities of BA patients, in order to prolong the survival rate of their native liver. Together with transplant surgeons, the bridging of BA patients to liver transplantation (LTx) becomes optimized and as a consequence of this interdisciplinary approach, the overall survival of babies with BA has already reached 90%. Furthermore, basic research into the still unknown origin of BA has advanced, and numerous scientific programs have already linked together. The overriding interest is to discover at least BA's etiology and to turn the treatment of BA patients from a symptomatic to a causative approach. Interdisciplinary and international programs are mandatory and already existing initiatives in Europe, the United States and Japan are going to coordinate their registries, clinical trials and basic research studies for the benefit of the patients and solve the riddle of BA.