Factors affecting survival after orthotopic liver transplantation in infants

The effect of an organ procurement organization surgeon on pediatric organ utilization

INTRODUCTION

Organ procurement organizations (OPO) have started to employ transplant-trained surgeons dedicated to organ procurement with the aim to increase allograft utilization and enhance the use of procured organs. We investigated the effects of an OPO-employed surgeon on the procurement and utilization of organs from pediatric donors within the Southwestern Transplant Alliance OPO.

METHODS

OPO data were obtained for all procurements that were performed between 2014 and 2019. The analysis was performed to see if the presence of an OPO donor surgeon impacted the utilization of pediatric livers. Donor and recipient demographic data were examined between allografts procured with the presence of an OPO surgeon (OPO-Present) and those without an OPO surgeon (OPO-Absent). A p-value of <.05 was considered significant.

RESULTS

Of 149 pediatric procurements, 91 included an OPO-donor surgeon. In procurements with OPO-Present, donors were younger (8.2 vs. 11.2, p < .05) and had longer distances to travel to the recipient center (334 vs. 175 miles p < .05), but had comparable cold ischemic times. In terms of organ share type, more OPO-Present livers were shared nationally and there was no difference in discard rate between OPO-Present and OPO-Absent procurements. Finally, OPO-Present livers were more likely to be transplanted to pediatric recipients compared to OPO-Absent (47.3% vs. 24.1% p < .05).

CONCLUSION

The presence of an OPO surgeon has impacted organ utilization, leading to increased transplantation of pediatric livers in pediatric recipients, and has expanded the geographical share of pediatric livers.

Whole liver transplantation in children under 10 kg: How to minimize the high risks of a still challenging procedure

BACKGROUND

Whole liver transplantation in infants <10 kg is a rare procedure with moderate outcomes (67%-79% graft survival at 1 year) and high rates of vascular complications (hepatic artery thrombosis 5-26%).

METHODS

Retrospective single-center analysis of whole liver transplantation in infants <10 kg and systematic review of the literature focused on survival rates and surgical complications.

RESULTS

Between January 2005 and December 2020, 175 liver transplantations in 173 children were performed at our center. A total of 92 (53%) children weighed less than 10 kg; 19 (21%) of them underwent WLT and constitute the study population. Median age of the recipients was 10 months (21 days-24 months) and median body weight 6.5 (3.1-9.8) kg. Median age of the donors was 5 (1-84) months and median body weight 6.1 (4-21) kg. Median donor-to-recipient body weight ratio was 1.2 (range: 0.6-4.5). Postoperatively, neither hepatic artery nor portal vein thrombosis occurred. A biliary complication occurred in 4 cases: 1 bile leak (early), 3 anastomotic stenoses (1 delayed and 2 late), and 1 non-anastomotic stenosis (late). Patient survival rate at 1, 5, and 10 years was 100%, 92%, and 92%, respectively. Overall, death-censored graft survival after 1, 5, and 10 was 100%.

CONCLUSION

Our results are excellent in terms of complications and graft and patient survival. This involves not only high-end surgical performance but also close interdisciplinary perioperative cooperation based on strong standard operating procedures and mainly focused on fluid management, hemostasiology, and strict monitoring of vessel patency.

Predictors of patient and graft survival following pediatric liver transplantation: Long-term analysis of more than 300 cases from single centre

BACKGROUND

Pediatric liver transplant (PLT) activity has flourished over time although with limited expansion in the graft pool. The study aims to identify pre-transplant factors that predict post-transplant patient and graft survival in the PLT population.

METHODS

Retrospective review of PLTs at a single tertiary transplant unit from 2000 to 2019. Univariate and multivariate analyses of pre-transplant factors were performed to identify predictors of patient and graft survival.

RESULTS

Two hundred and seventy-six patients received 320 PLTs. The most common cause of graft loss was hepatic artery thrombosis (n = 13, 29.6%). The most common cause of mortality was sepsis (n = 11, 29.7%). Univariate analysis showed that the following variables had a significant (p < .05) impact on patient survival: recipient age, weight, height, graft type (technical variant graft), transplant category (acute liver failure), the era of transplant, and invasive ventilation. The following variables had a significant (p < .05) impact on graft survival: recipient age, weight, height, transplant category (acute liver failure), and the era of transplant. Multivariate analysis precluded the era of transplant as the only significant factor for patient survival; patients transplanted after 2005 had significantly higher patient survival. No independent factor predicting graft survival was identified. For children transplanted after 2005, the only factor that predicted patient survival was pre-transplant invasive ventilation.

CONCLUSIONS

Our study suggests that the learning curve and pre-transplant invasive ventilation in the recipient have a significant impact on patient survival. The traditional view of worse outcomes of smaller PLT candidates should be changed.

Determinants of short-term outcomes after pediatric liver transplantation: a single centre experience over 20 years

BACKGROUND

Liver transplantation (LT) is a standard-of-care therapeutic modality for selected patients with life-threatening liver disease, including children. In addition to specific clinical characteristics of pediatric LT recipients due to initial liver disease (and related comorbidities) and level of liver failure, early postoperative outcome may be dependent on the surgical technique used, related to the type of organ donor and graft. Therefore, the aims of the present retrospective study from a large single centre cohort were to identify the prognostic factors for both 1-year patient and graft survival.

METHODS

Between October 1990 and October 2010, 151 children underwent a first LT in our centre.

RESULTS

The mean age was 5.3 ± 7.4 years, and the main indication was biliary atresia (BA) (49.0%). Living donor liver transplantation (LDLT) was performed in 39 cases (25.8%). Cadaveric liver graft was a whole liver in 50 cases (33.1%) and a partial liver (reduced or split) in 62 cases (41.1%). One-year patient and graft survival rates were 88.7% and 86.1%, respectively. Multivariate analysis disclosed that initial liver disease, location at time of LT, donor/recipient (D/R) delta age, early post-transplant hemodialysis and initial immunosuppression (induction) were significantly associated with patient survival and that D/R delta age, primary non-function, early post-transplant hemodialysis and initial immunosuppression (induction) were significantly associated with graft survival.

CONCLUSION

The results of our single-centre experience of pediatric LT emphasize that early patient and graft survivals depend on pre-operative/operative factors such as initial liver disease, D/R delta age and immunosuppressive regimen. Awareness of these factors can help in the decision making for children requiring LT.

Post-operative heparin reduces early venous thrombotic complications after orthotopic paediatric liver transplantation

BACKGROUND

Despite significant improvements in surgical techniques and medical care, thrombotic complications still represent the primary cause of early graft failure and re-transplantation following paediatric liver transplantation. There is still no standardized approach for thrombosis prevention.

MATERIALS AND METHODS

The study aimed to evaluate the effectiveness of early intravenous unfractionated heparin started 12 hours postoperatively at 10 UI/kg per hour and used a retrospective "before and after" design to compare the incidence of early thrombotic complications prior to (2002-2010) and after (2011-2016) the introduction of heparin in our institute.

RESULTS

From 2002 to 2016, 479 paediatric patients received liver transplantation in our institution with an overall survival rate over one year of 0.91 (95% CI: 0.87-0.94). Of 365 eligible patients, 244 did not receive heparin while 121 did receive heparin. We reported a lower incidence of venous thrombosis (VT) in the group treated with heparin: 2.5% (3/121) vs 7.9% (19/244) (p=0.038). All clinical and laboratory variables considered potential risk factors for VT were studied. By multivariate stepwise Cox proportional hazards models, heparin prophylaxis resulted significantly associated to a reduction in VT (HR=0.29 [95% CI: 0.08-0.97], p=0.045), while age <1 year was found to be an independent risk factor for VT (HR=2.62 [95% CI: 1.11-6.21]; p=0.028).

DISCUSSION

Early postoperative heparin could be considered a valid and safe strategy to prevent early VT after paediatric liver transplantation without a concomitant increase in bleeding. A future randomised control trial is mandatory in order to strengthen this conclusion.

Outcomes following liver transplantation in young infants: Data from the SPLIT registry

Liver transplantation (LT) in young patients is being performed with greater frequency. We hypothesized that objective analysis of pre-, intra-, and postoperative events would help understand contributors to successful outcomes and guide transplant decision processes. We queried SPLIT registry for pediatric transplants between 2011 and 2018. Outcomes were compared for age groups: 0-<3, 3-<6, 6-<12 months, and 1-<3 years (Groups A, B, C, D respectively) and by weight categories: <5, 5-10, >10 kg; 1033 patients were available for analysis. Cholestatic disease and fulminant failure were highest in group A and those <5 kg; and biliary atresia in group C (72.8%). Group A had significantly higher life support dependence (34.6%; P < .001), listing as United Network for Organ Sharing status 1a/1b (70.4%; P < .001), and shortest wait times (P < .001). The median (interquartile range) for international normalized ratio and bilirubin were highest in group A (3.0 [2.1-3.9] and 16.7 [6.8-29.7] mg/dL) and those <5 kg (2.6 [1.8-3.4] and 13.5 [3.0-28.4] mg/dL). A pediatric end -stage liver disease score ≥40, postoperative hospital stays, rejection, and nonanastomotic biliary strictures were highest in group A with lowest survival at 93.1%. Infants 0 to <3 months and those <5 kg need more intensive care with lower survival and higher complications. Importantly, potential LT before reaching status 1a/1b and aggressive postoperative management may positively influence their outcomes.

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.

Pediatric Liver Transplantation: Then and Now

This paper reviews the past 50 years of liver transplantation in children from the perspective of patient demographics, perioperative patient management, surgical techniques, immunosuppression and patient outcomes.

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.

Perioperative thrombotic complications associated with pediatric liver transplantation: a UNOS database evaluation

BACKGROUND

This retrospective UNOS database evaluation analyzes the prevalence of preoperative portal vein thromboses (PVT), and postoperative thromboses leading to graft failure in pediatric patients undergoing liver transplantation (LT).

METHODS

The evaluation was performed in three age groups: I (0-5), II (6-11), III (12-18) years old. Factors predictive of pre- and postoperative thromboses were analyzed.

RESULTS

Between 2000 and 2015, 8982 pediatric LT were performed in the US. Of those, 390 patients had preoperative PVT (4.3%), and 396 (4.4%) had postoperative thromboses. The prevalence of both types of thromboses was less in Group III than in the other two groups (3.20% vs 4.65%, p = 0.007 and 1.73% vs. 5.13%, p < 0.001, respectively). The prevalence of postoperative thromboses was significantly higher in Group I than in the other two groups (5.49% vs. 2.51%, p < 0.001). Preoperative PVT was independently associated with postoperative thromboses (OR = 1.7, p = 0.02). Children less than 5 years of age were more likely to develop postoperative thromboses leading to graft failure (OR = 2.9, p < 0.001).

CONCLUSION

Younger children undergoing LT are prone to pre-and postoperative thrombotic complications. Preoperative PVT at the time of transplantation was independently associated with postoperative thromboses. Perioperative antithrombotic therapy should be considered in pediatric patients undergoing LT.

Computed tomography donor liver volumetry before liver transplantation in infants ≤10 kg: does the estimated graft diameter affect the outcome?

Aim of the study

Living donor liver transplantation (LDLT) is regularly performed in small-sized infants. Computed tomography (CT)-based donor liver volumetry is used to estimate the graft size. The aim of our study was to assess the results of CT liver volumetry and their impact on the clinical outcome after LDLT in extremely small-sized infants.

Patients and methods

In this study, we included all patients with a body weight of ≤10 kg who underwent living related liver transplantation at our centre between January 2004 and December 2014. In all cases of LDLT, a preoperative CT scan of the donor liver was performed, and the total liver and graft volumes were calculated. The graft shape was estimated by measuring the ventro-dorsal (thickness), cranio-caudal, and transversal (width) diameter of segment II/III. We assessed the impact of CT donor liver volumetry and other risk factors on the outcome, defined as patient and graft survival.

Results

In the study period, a total of 48 living related liver transplantations were performed at our centre in infants ≤10 kg [20 male (42%), 28 female (58%)]. The mean weight was 7.3 kg (range 4.4–10 kg). Among the recipients, 33 (69%) received primary abdominal closure and 15 (31%) had temporary abdominal closure. The patient and graft survival rates were 85% and 81%, respectively. In CT volumetry, the mean estimated graft volume was 255 mL (range 140–485 mL) and the actual measured mean graft weight was 307 g (range 127–463 g). The mean ventro-dorsal diameter of segment II/III was 6.9 cm (range 4.3–11.2 cm), the mean cranio-caudal diameter was 9 cm (range 5–14 cm), and the mean width was 10.5 cm (range 6–14.7 cm). The mean graft-body weight ratio (GBWR) was 4.38% (range 1.41–8.04%). A high graft weight, a GBWR >4%, and a large ventro-dorsal diameter of segment II/III were risk factors for poorer patient survival.

Conclusion

Preoperative assessment of the graft size is a crucial investigation before LDLT. For extremely small-sized recipients, not only the graft weight but also the graft shape seems to affect the outcome.

Postoperative complications in cirrhotic pediatric deceased donor liver transplantation: Focus on transfusion therapy

Intraoperative transfusions seem associated with patient death and graft failure after PLTx. A retrospective analysis of recipients' and donors' characteristics and transplantation data in a cohort of patients undergoing PLTx from 2002 to 2009 at the Bergamo General Hospital was performed. A two-stage hierarchical Cox proportional hazard regression with forward stepwise selection was used to identify the main risk factors for major complications. In addition, propensity score analysis was used to adjust risk estimates for possible selection biases in the use of blood products. Over the 12-year period, 232 pediatric cirrhotic patients underwent PLTx. One-year patient and graft survival rates were 92.3% and 83.7%, respectively. The Kaplan-Meier shows that the main decrease in both graft and patient survival occurs during the first months post-transplantation. At the same time, it appears that most of the complications occur during the first month post-transplantation. One-month and 1-year patient complication-free survival rates were 24.8% and 12.1%, respectively. Our study shows that intraoperative red blood cells and platelet transfusions are independent risk factors for developing one or more major complications in the first year after PLTx. Decreasing major complications will improve the health status and overall long-term patient survival after pediatric PLTx.

Isolated Orthotopic Liver Transplantation for Parenteral Nutrition–Associated Liver Injury

BACKGROUND

Mild liver dysfunction is common after prolonged use of parenteral nutrition (PN), but end-stage liver failure occurs only rarely. Few treatment options other than combined liver-intestine transplantation exist for patients with liver failure associated with PN use, however. Herein, we report the results of a cohort of patients undergoing isolated orthotopic liver transplantation (OLT) for PN-associated liver injury.

METHODS

A retrospective cohort study of 80 patients (73 pediatric patients and 7 adults) who have undergone isolated OLT for PN-associated liver injury as the primary indication for transplantation was performed.

RESULTS

At the time of OLT, the mean total serum bilirubin was 19.5 mg/dL and the mean serum albumin level was 2.9 mg/dL. Severe hepatic encephalopathy was seen in 5%, spontaneous bacterial peritonitis was seen in 6.3%, and respiratory failure requiring mechanical ventilation was seen in 14% of patients at the time of OLT. Overall 1- and 5-year survival rates were 72% and 52%, respectively, with infection being the most common cause of death after OLT. Retransplantation was required in 25% of patients, and the 5-year posttransplant patient survival rate only reached 35% in these cases.

CONCLUSIONS

Patients with end-stage liver disease associated with PN administration often have very severe liver disease, multiple comorbidities, and poor prognosis by the time they are listed for OLT. Nonetheless, isolated OLT is associated with good long-term survival and should be considered for selected patients with combined intestine-liver failure.

Coagulopathy and transfusion therapy in pediatric liver transplantation

Bleeding and coagulopathy are critical issues complicating pediatric liver transplantation and contributing to morbidity and mortality in the cirrhotic child. The complexity of coagulopathy in the pediatric patient is illustrated by the interaction between three basic models. The first model, "developmental hemostasis", demonstrates how a different balance between pro- and anticoagulation factors leads to a normal hemostatic capacity in the pediatric patient at various ages. The second, the "cell based model of coagulation", takes into account the interaction between plasma proteins and cells. In the last, the concept of "rebalanced coagulation" highlights how the reduction of both pro- and anticoagulation factors leads to a normal, although unstable, coagulation profile. This new concept has led to the development of novel techniques used to analyze the coagulation capacity of whole blood for all patients. For example, viscoelastic methodologies are increasingly used on adult patients to test hemostatic capacity and to guide transfusion protocols. However, results are often confounding or have limited impact on morbidity and mortality. Moreover, data from pediatric patients remain inadequate. In addition, several interventions have been proposed to limit blood loss during transplantation, including the use of antifibrinolytic drugs and surgical techniques, such as the piggyback and lowering the central venous pressure during the hepatic dissection phase. The rationale for the use of these interventions is quite solid and has led to their incorporation into clinical practice; yet few of them have been rigorously tested in adults, let alone in children. Finally, the postoperative period in pediatric cohorts of patients has been characterized by an enhanced risk of hepatic vessel thrombosis. Thrombosis in fact remains the primary cause of early graft failure and re-transplantation within the first 30 d following surgery, and it occurs despite prolongation of standard coagulation assays. Data, however, are currently lacking regarding the use of anti-aggregation/anticoagulation therapies and how to best monitor for thrombosis in the early postoperative period in pediatric patients. Therefore, further studies are necessary to elucidate the interaction between the development of the coagulation system and cirrhosis in children. Moreover, strategies to optimize blood transfusion and anticoagulation must be tested specifically in pediatric patients. In conclusion, data from the adult world can be translated with difficulty into the pediatric field as indication for transplantation, baseline pathologies and levels of pro- and anticoagulation factors are not comparable between the two populations.

Living Related Liver Transplantation for Biliary Atresia in the Last 5 years: Experience from the First Liver Transplant Program in India

OBJECTIVE

To study the clinical, biochemical profile and outcome of patients with biliary atresia (BA) who underwent living related liver transplantation (LRLT) at authors' institute in the last 5 y (2008-2013).

METHODS

Case records of the 20 patients diagnosed with biliary atresia who had undergone living related liver transplantation at authors' centre in the last 5 y were analysed.

RESULTS

Eighteen patients with BA with a failed Kasai procedure and 2 without a prior Kasai's portoenterostomy received a liver transplant. At a median follow up of 2 y and 6 mo, both the patient and graft survival rates were 90 %. The median age of the recipients at the time of LRLT was 8 mo and 12 (60 %) of the transplanted children were less than or equal to 1 y of age. The male-female ratio was 1.8:1. The median weight was 7.3 kg (5.8-48 kg); two thirds were less than 10 kg. The median pre-transplant total serum bilirubin (TSB) and international normalized ratio (INR) were 12.98 (0.5-48.3) mg/dl and 1.3 (1.0-3.9) respectively. All patients received a living related graft and there was no donor mortality. The median duration of postoperative ventilation was 14 h. The post-operative complications were infection (30 %), vascular complications (20 %) and acute rejection (20 %). The median duration of postoperative hospital stay was 21 d (17-42). Two patients died of combined hepatic and portal vein thrombosis in the early postoperative period. Late rejection was encountered in 1 patient and another developed chronic kidney disease necessitating a renal transplant. There were no late vascular occlusions or development of post transplant lymphoproliferative disease.

CONCLUSIONS

Thus, LRLT for BA with or without a prior portoenterostomy, is a feasible and successful treatment modality with good outcomes attained despite the challenges of age and size. This treatment modality is now well established in India.

Outcomes of Technical Variant Liver Transplantation versus Whole Liver Transplantation for Pediatric Patients: A Meta-Analysis

Objective

To overcome the shortage of appropriate-sized whole liver grafts for children, technical variant liver transplantation has been practiced for decades. We perform a meta-analysis to compare the survival rates and incidence of surgical complications between pediatric whole liver transplantation and technical variant liver transplantation.

Methods

To identify relevant studies up to January 2014, we searched PubMed/Medline, Embase, and Cochrane library databases. The primary outcomes measured were patient and graft survival rates, and the secondary outcomes were the incidence of surgical complications. The outcomes were pooled using a fixed-effects model or random-effects model.

Results

The one-year, three-year, five-year patient survival rates and one-year, three-year graft survival rates were significantly higher in whole liver transplantation than technical variant liver transplantation (OR = 1.62, 1.90, 1.65, 1.78, and 1.62, respectively, p<0.05). There was no significant difference in five-year graft survival rate between the two groups (OR = 1.47, p = 0.10). The incidence of portal vein thrombosis and biliary complications were significantly lower in the whole liver transplantation group (OR = 0.45 and 0.42, both p<0.05). The incidence of hepatic artery thrombosis was comparable between the two groups (OR = 1.21, p = 0.61).

Conclusions

Pediatric whole liver transplantation is associated with better outcomes than technical variant liver transplantation. Continuing efforts should be made to minimize surgical complications to improve the outcomes of technical variant liver transplantation.

Pediatric transplantation: preventing thrombosis

Due to progressive advances in surgical techniques, immunosuppressive therapies, and supportive care, outcomes from both solid organ transplantation and hematopoietic stem cell transplantation continue to improve. Thrombosis remains a challenging management issue in this context, with implications for both graft survival and long-term quality of life. Unfortunately, there remains a general paucity of pediatric-specific data regarding thrombosis incidence, risk stratification, and the safety or efficacy of preventative strategies with which to guide treatment algorithms. This review summarizes the available evidence and rationale underlying the spectrum of current practices aimed at preventing thrombosis in the transplant recipient, with a particular focus on risk factors, pathophysiology, and described antithrombotic regimens.

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.

More benign lymphoproliferative disease after liver transplant in infants

CONTEXT-Despite the high frequency of liver transplants in infants, few data are available on the characteristics of posttransplant lymphoproliferative disorders in liver transplant patients (PTLD). OBJECTIVE-To analyze special features and behavior of PTLD arising after liver transplant in infants. METHODS-A comprehensive search of the literature was conducted for the available data on PTLD in infant liver transplant recipients through PubMed and Google scholar. An infant was defined as a liver recipient who was less than 2 years old at the time of transplant. Overall, 205 cases of PTLD were found in 24 reports, and the 100 infants with PTLD were compared with children and adults with PTLD. RESULTS-PTLD lesions in infants were more likely to be polymorphic whereas monomorphic lesions were more prevalent among older patients (P= .05). Remission rates, metastasis frequency, and organ involvement did not differ significantly between the groups. Survival analysis showed that the infants had a significantly better outcome than did older patients (P= .05). CONCLUSION-PTLD is more benign and may have a better outcome in infant liver transplant recipients than in older recipients. A prospective multicenter approach is needed for future research studies.

Multivisceral transplantation using a 2.9 kg neonatal donor

Prematurity and very low birthweight have often been considered relative contraindications to neonatal organ donation. Organ procurement from neonatal donors is further complicated by unclear guidelines regarding neonatal brain death. We report a successful case of multivisceral transplantation using a graft from a 10-day-old, 2.9 kg, neonatal donor born at 36 6/7 wk in a 3.2 kg, three month old with intestinal and liver failure secondary to midgut volvulus. There was immediate liver graft function with correction of recipient coagulopathy, but delayed normalization of laboratory values and delayed return of bowel function. At six-yr post-transplant follow-up, the patient has normal intestine and liver function. Her last histologically confirmed rejection episode was 30 months prior to last follow-up. This case suggests that multivisceral grafts from very young or small neonatal donors may be transplanted successfully in selected cases. We propose a re-examination of the brain death guidelines for premature and young infants to potentially increase the availability of organs for infant recipients.

The impact of perioperative transfusion of blood products on survival after pediatric liver transplantation

Intraoperative transfusion of red blood cells (RBC) is associated with adverse outcome after LT in adult patients. This relationship in pediatric patients has not been studied in depth, and its analysis is the scope of this study. Forty-one variables associated with outcome, including blood product transfusions, were studied in a cohort of 243 pediatric patients undergoing a cadaveric LT between 2002 and 2009 at the General Hospital of Bergamo. Multivariate stepwise Cox proportional hazards models were adopted with adjustment by propensity scores to minimize factors associated with the use of blood products. Median age at transplant was 1.37 yr. In uni- and multivariate analyses, perioperative transfusion of FFP and RBC was an independent risk factor for predicting one-yr patient and graft survival. The effect on one-yr survival was dose-related with a hazard ratio of 3.15 for three or more units of RBC (p = 0.033) and 3.35 for three or more units of FFP (p = 0.021) when compared with 1 or no units transfused. The negative impact of RBC and FFP transfusion was confirmed by propensity score-adjusted analysis. These findings may have important implications for transfusion practice in the LT pediatric recipients.

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.

Early detection of the graft failure after pediatric liver transplantation: a Bergamo experience

BACKGROUND

Effective indicators of the early graft failure after pediatric liver transplantation are currently a crucial question. The aim of this study was to analyze retrospectively laboratory parameters that may help anticipate an early graft loss (GL).

METHODS

The 131 pediatric liver transplantations, performed in our hospital from January 2002 to December 2005, were reviewed. Post-operative laboratory parameters, collected in the first 36 h of the Paediatric Intensive Care Unit (PICU) stay, were analyzed for children with both graft survival and GL. Receiver operating characteristics analysis was used to identify the optimal cut-off for the laboratory parameters. Multivariate logistic regression analysis was used to calculate the adjusted risk of GL for the prognostic parameters identified.

RESULTS

The mean age at transplant was 1.1 years. The two groups were comparable for all recipient and donor variables considered. Children with GL showed significantly higher levels of ammonia and transaminase at the admission to the PICU and higher levels of prothrombin time, creatinine, lactate and a lower level of platelets at the 36 h of PICU. The laboratory parameters over the cut-off value by the multivariate logistic regression identified all early thromboses earlier than Doppler ultrasound.

CONCLUSIONS

This study suggests that routine blood tests may help to anticipate an early loss of liver grafts in children after transplantation and may improve our diagnostic investigation in the case of thrombosis suspicion. Further validation by a prospective study is needed to carefully assess the sensitivity and specificity of the identified criteria.

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.

Long-term results of urgent revascularization for hepatic artery thrombosis after pediatric liver transplantation

Hepatic artery thrombosis (HAT) after pediatric orthotopic liver transplantation (OLT) is a serious complication resulting in bile duct necrosis and often requiring retransplantation. Immediate surgical thrombectomy/thrombolysis has been reported to be a potentially successful treatment for restoring blood flow and avoiding urgent retransplantation. The long-term results of this strategy remain to be determined. In 232 pediatric liver transplants, we analyzed long-term outcomes after urgent revascularization for early HAT. HAT developed in 32 patients (13.7%). In 16 children (50%), immediate surgical thrombectomy was performed in an attempt to salvage the graft. Fourteen patients (44%) underwent urgent retransplantation, and 2 (6%) died before further intervention. Immediate thrombectomy resulted in long-term restoration of the hepatic artery flow in 6 of 16 patients (38%) and in 1- and 5-year graft and patient survival rates of 83% and 67%, respectively. In 10 patients, revascularization was unsuccessful, and retransplantation was inevitable. The 1- and 5-year patient survival rates in this group decreased to 50% and 40%, respectively. After immediate retransplantation, the 5-year patient survival rate was 71%. In conclusion, immediate surgical thrombectomy for HAT after pediatric OLT results in long-term graft salvage in about one-third of patients. However, when thrombectomy is unsuccessful, long-term patient survival is lower than the survival of patients who underwent immediate retransplantation.

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.

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.

Outcomes following liver transplantation

As the field of Liver Transplantation has matured, survival alone is no longer an acceptable single metric of success. This chapter explores the impact of the PELD system for donor organ allocation, surgical modification of donor organs, living donation, and long-term transplant-related complications on overall quality of life and outcome. Strategies to improve survival, overall outcome, and health-related quality of life in long-term recipients are outlined.

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.

Predictors of outcomes after pediatric liver transplantation: an analysis of more than 800 cases performed at a single institution

BACKGROUND

Pediatric liver transplantation (PLTx) is the standard of care for treatment of liver failure in children. Unfortunately, there are few studies with substantial numbers of patients that identify outcomes predictors. The goal of this study was to determine factors that influence outcomes in a large, single-center cohort of PLTx.

STUDY DESIGN

This retrospective review between 1984 to 2006 included all recipients 18 years of age and younger undergoing PLTx. Multiorgan graft recipients were excluded (n = 48). Data sources included transplantation center database and hospital medical records. Outcomes measures were overall patient and graft survival. Demographic, laboratory, and perioperative variables were analyzed. Univariate and multivariate statistical analysis was undertaken using log-rank test and Cox's proportional hazards model. A p value < 0.05 was considered significant at the multivariate level.

RESULTS

Eight hundred fifty-two PLTx were performed in 657 children; 55% were girls, 45% were Hispanic, and median age was 29.5 months. Biliary atresia and acute liver failure were the most common causes of liver disease. Fifty-two percent were hospitalized before PLTx. Graft types were whole (75%) and segmental (25%). Indications for re-PLTx (n = 195) included graft nonfunction (22%), immunologic (34%), and vascular complications (35%). Overall 1-, 5-, and 10-year survival rates were 85%, 81%, and 78% (patient), and 78%, 72%, and 67% (graft). Independent significant predictors of worse patient survival were renal function, pretransplantation ventilator dependence, and causes of liver disease. Independent significant predictors of worse graft survival were renal function and warm ischemia time.

CONCLUSIONS

As one of the largest, single-center analyses of PLTx, this study enables accurate statistical analysis and demonstrates excellent longterm outcomes. Independent prognosticators of graft survival were renal function and warm ischemia time, and those for patient survival were renal function, mechanical ventilation, and causes of liver disease. These factors can aid in the medical decision making required for optimal use of scarce donor organs.

Liver Transplantation for Small Babies

Orthotopic liver transplantation remains a major medical and surgical challenge in small pediatric patients. From April 2003 to June 2006, 21 small babies (each of whom weighed less than 10 kg or was younger than 1 year of age) underwent orthotopic liver transplantation. Five were girls and 16 were boys with a mean age of 15.7 +/- 9.3 months (range, 2-24 months); their mean weight at the time of transplantation was 9.8 +/- 3.6 kg (range, 6-16 kg). All transplants were obtained from a living-related donor. Left lateral segment was used for all transplantations. The median graft-to-recipient weight ratio was 3.5% +/- 1.2% (range, 1.5%-6.1%). During the early postoperative period, hepatic arterial thrombosis was identified in 4 patients, and a biliary leak was detected in 2 patients. In 2 patients, portal vein stenosis was identified during the late postoperative period. At the time of this writing, the 17 alive patients (81%) exhibited good graft function at median follow-up of 14.8 +/- 10.9 months (range, 1-39 months). Four patients died during the follow-up. Histological examination revealed hepatocellular carcinoma in 2 patients, and Burkitt's lymphoma in 1 patient. In conclusion, our data confirmed that living-related donors, especially in this age group, provide a reliable source for the organ pool. Satisfactory results can be achieved despite the anatomic handicaps of this age group.

Liver transplantation in very small infants

BACKGROUND

This study examines the results of liver transplantation (LT) in children 5 kg or less. Reports suggest an increased morbidity and mortality in children weighing 5 kg or less as compared to larger children. However, over half of all children needing LT are <1 year old. Improving outcomes in very small children is a major goal of liver transplantation.

METHODS

All children under 21 years of age transplanted from January 1990 to June 2005 were included in this study. One hundred sixty-eight primary liver transplants were done: 61 in children less than one year of age and 20 in infants weighing 5 kg or less at LT (2 to 5 kg). These 20 infants underwent 23 transplants. Whole organs were used in 39% of transplants, and reduced or split grafts were used in 61%. Arterial reconstruction using aortic conduits was done in 22%. Analysis included Fischer's exact or Chi square test for non-parametric analysis while patient survival was calculated using the Kaplan-Meier method test with differences in survival assessed using the log rank test.

RESULTS

Five-year survival for infants 5 kg or less was 74%, and graft survival was 60%, which was not different from patients transplanted that were >5 kg. There were three perioperative deaths, one from primary graft non-function, and two from portal vein thrombosis. There were no bile leaks or hepatic artery thromboses. Bacterial, fungal, and viral infections made up the vast majority of the postoperative complications (65%), with viral infections resulting in two graft losses requiring re-transplantation. Rejection occurred in 25% of patients, of which one required OKT3. Five of the 23 liver transplants in infants less than 5 kg were done prior to 1996, with a five-year graft survival of only 20%. Improvements in technique and postoperative care after 1996 led to improved graft and patient survival of 77% and 86% respectively.

CONCLUSIONS

Liver transplantation for infants weighing less than 5 kilograms can be technically challenging but can have equivalent graft and patient survival when compared to larger children requiring liver transplantation. Infants should not be denied liver transplantation based on weight alone.

Immune-cell treatment of Epstein–Barr-virus-associated lymphoproliferative disorders

Lymphoproliferative disorders associated with Epstein--Barr virus (EBV) after bone-marrow or organ transplantation express all the immunogenic EBV antigens, and reduction in immunosuppressive treatment can result in permanent resolution. As such, the disease lends itself to EBV-directed immune-cell therapy. Successes have been achieved with both manipulated and unmanipulated T-cell infusions for lymphoproliferations occurring after bone-marrow transplantation. Several practical challenges have been overcome in applying EBV-specific T-cell therapy to the setting of organ-transplant-related lymphoproliferations. These include the generation of autologous cytotoxic T lymphocytes (CTLs), the creation of a partially HLA-matched cryopreserved allogeneic CTL bank, and the generation of autologous EBV-specific CTLs from EBV-naïve pediatric patients. The efficacy of immune-cell therapy in the setting of solid-organ transplantation is less well established than it is after T-cell-depleted allogeneic bone-marrow transplantation, and it is as yet not clear how to best to integrate CTL therapy with the anti-B-cell antibody rituximab, which has significant activity against these lymphoproliferations.

Neonatal hemochromatosis: long-term experience with favorable outcome

OBJECTIVE

Neonatal hemochromatosis is a severe, often fatal multiorgan disorder of iron metabolism. Liver transplantation can be curative; the benefit of antioxidant treatment is discussed controversially. We summarize our experience with neonatal hemochromatosis over the past 13 years.

METHODS

A retrospective study was performed of 16 patients with acute liver failure attributable to neonatal hemochromatosis between 1992 and 2004.

RESULTS

Median age at the onset of neonatal hemochromatosis was 2 days (range: 0-21 days). Median weight at the time of diagnosis was 2900 g (range: 1520-4200 g). All patients had elevated ferritin levels (median: 4179 microg/L), and transferrin saturation (median: 99%). Fourteen patients (87.5%) showed significant hepatocyte siderosis in biopsies; 4 children had additional iron deposition in extrahepatic tissue. Four patients were diagnosed by MRI. Seven infants received liver transplants, 5 of them in combination with a preceding antioxidant treatment. Four children (25%) received antioxidants without the necessity of liver transplantation and were in good clinical condition at the time of this evaluation. Five patients (31.3%) died, 3 of them without any treatment because of initial fulminant multiorgan failure. In September 2005, 68.7% of the patients were still alive after a median follow-up of 5 years.

CONCLUSIONS

Neonatal hemochromatosis is a severe metabolic disease, but early antioxidant treatment and liver transplantation in addition to optimal medical care can improve the outcome dramatically. Children with moderate liver failure can survive without liver transplantation, but should be monitored closely for deterioration.

Evaluation and management of patients with propionic acidemia undergoing liver transplantation: a comprehensive review

Propionic acidemia is a rare metabolic disorder that often results in episodic hyperammonemia, basal ganglia infarction, mental retardation, and cardiomyopathy. OLT has been used as a treatment for propionic acidemia, but its benefit in patients with this disease is unclear. The current study was undertaken to clarify the role of OLT in the management of this disease. The medical literature, a national registry of US OLT recipients, and a single institution liver transplant experience were reviewed for cases of OLT for propionic acidemia. Accumulated cases demonstrate that OLT has resulted in clear evidence of clinical improvement in several patients, often obviating the need for dietary restriction or other forms of medical management. OLT appears to halt the decline in neurocognitive function often associated with propionic acidemia. In total, 12 patients with propionic acidemia have undergone a total of 14 OLTs. A quantitative analysis of outcomes shows an overall patient survival rate of 72.2% at one year after OLT. In conclusion, OLT should be considered a treatment option for patients with propionic acidemia who continue to experience episodes of hyperammonemia in spite of maximal medical therapy. Early OLT may limit the development of mental retardation and/or cardiomyopathy.

Mortality risk score in liver transplantation: changes over time in its predicting power

Since the onset of our liver transplantation program in 1992, 362 transplants were performed in 338 children. A risk score for predicting mortality was designed and implemented over time. The description of a method utilized to design the risk score, changes in mortality rate over 12 yr and the analysis of factors that might have influenced these changes are presented and discussed in this paper.

PATIENTS AND METHODS

Cox regression analysis was applied to a retrospective sample of 110 patients with liver cirrhosis, transplanted between 1992 and 2000. A risk score was prepared using beta coefficients of the two significant variables related to survival time: age (1.08, p=0.02) and bilirubin levels (0.93, p=0.03), and two groups were identified: low- and high-risk score. The score was applied in two consecutive samples: 2000-2002 and 2002-2004.

RESULTS

In the first sample (1992-2000), we found 69 and 41 as low- and high-risk patients, with a median survival time of 93.13 and 2.93 months (p=0.0001). In the 2000-2002 sample, a median survival time of 41.7 and 2.33 months (p=0.03) was found for low- and high-risk groups, respectively. In the third sample (2002-2004), there was a remarkable decrease in mortality in the high-risk group (n=29) and the score did not discriminate between high- and low-risk groups (p=0.35).

CONCLUSION

A scoring system to identify risk levels in liver transplantation patients is an operative and powerful tool during a given period of time but it has to be updated as risk factors will vary following the team's learning curve.

Liver transplant in a four-month-old child with biliary atresia, unilateral pulmonary agenesis, and diaphragmatic hernia: first case report

Bilateral pulmonary agenesis (PA) is a rare embryological defect incompatible with life. Unilateral PA has a wide range of clinical presentations: its prognosis depends on the presence and severity of other associated anomalies. Fetal biliary atresia has been associated with a number of congenital anomalies, but the etiology is still not understood. An unusual case of a child with right PA, right diaphragmatic hernia, and delayed diagnosed biliary atresia leading to liver failure is presented herein. At the age of 4 months the patient was referred to the Transplant Department at Children Healthcare of Atlanta at Egleston with cholestasis and failure to thrive. With a rapidly progressive liver insufficiency, this child was evaluated for liver transplantation. In the absence of any respiratory symptom, the patient received a deceased donor size-matched left lateral segment liver transplant, which covered the diaphragmatic defect, with no further repair required. Twenty-seven months post-transplant, the patient has good graft function, a normal Z-score and is thriving. In spite of the increased physiological and surgical challenges (absence of right lung tissue, hemi-diaphragm, and ectopic position of the liver in the right chest), liver transplantation was performed with positive outcome in this high-risk child. Whether PA, may have developmentally contributed to expression of biliary atresia will need further investigation.

Evaluation of dichloroacetate treatment in a murine model of hereditary tyrosinemia type 1

Hereditary tyrosinemia type 1 (HT1) is an autosomal recessive disease severely affecting liver and kidney and is caused by a deficiency in fumarylacetoacetate hydrolase (FAH). Administration of 2-(2-nitro-4-trifluoro-methylbenzyol)-1,3 cyclohexanedione (NTBC) improves the HT1 phenotype but some patients do not respond to NTBC therapy. The objective of the present study was to evaluate whether administration of dichloroacetate, an inhibitor of maleyl acetoacetate isomerase (MAAI) to FAH-knockout mice could prevent acute pathological injury caused by NTBC withdrawal. DCA (0.5 and 5g/L) was given in combination with a standard diet or with a tyrosine-restricted diet. With the low-tyrosine diet body weight loss and most of hepatic and renal injuries were prevented regardless the DCA dose. The administration of DCA with a standard diet did not prevent damage nor the oxidative stress response nor the AFP induction seen in FAH-knockout mice. DCA was shown to inhibit hepatic MAAI activity to 86% (0.5g/L) and 94% (5g/L) of untreated wild-type mice. Interestingly, FAH(-/-) mice deprived of NTBC (NTBC-OFF) and NTBC-treated FAH-knockout mice had similar low hepatic MAAI activity levels, corresponding to 10-20% of control. Thus the failure of DCA treatment in FAH(-/-) mice seems to be attributed to the residual MAAI activity, high enough to lead to FAA accumulation and HT1 phenotype.

Orthotopic liver transplantation for biliary atresia: the U.S. experience

Biliary atresia is the most common indication for orthotopic liver transplantation (OLT) in the pediatric population. The outcomes of liver transplantation for biliary atresia, however, have not been formally examined on a national scale. The objective of this study was to identify pretransplant variables that predict patient survival after primary liver transplantation for biliary atresia. A cohort of 1,976 pediatric patients undergoing primary liver transplantation for biliary atresia between 1/1988 to 12/2003 was enrolled from the United Network for Organ Sharing database after excluding patients with a history of multiorgan transplant or previous liver transplant. Follow-up data up to 16 years post-OLT was available. The 5- and 10-year actuarial survival rates of patients that underwent liver transplantation for biliary atresia in the United States are 87.2% and 85.8%, respectively, and the 5- and 10-year graft actuarial survival rates are 76.2% and 72.7%, respectively. Early deaths (< or =90 days post-OLT) were more often caused by graft failure (P = 0.01), whereas late deaths (>90 days post-OLT) were more often due to malignancy (P < 0.01). An analysis of outcomes over time demonstrated a decrease in post-OLT survival and an increase in the number of OLTs done for biliary atresia at an increasing number of centers. A multivariate analysis revealed that cadaveric partial/reduced liver grafts, a history of life support at the time of OLT, and decreased age were independent predictors of increased post-OLT mortality. In conclusion, OLT is an effective treatment for biliary atresia. Certain pretransplant variables may help predict patient survival following liver transplantation for biliary atresia.

Right-sided diaphragmatic hernia in infants after liver transplantation

Liver transplantation is just as successful in infants as in older children, but more challenging. This relates to the low weight of the recipients and to their rapidly deteriorating clinical condition (malnutrition and end-stage liver disease) ( J Pediatr 1990;117:205-210; BMJ 1993;307:825-828; Ann Surg 1996;223:658-664; Transplantation 1997;64:242-248; J Pediatr Surg 1998;33:20-23). In addition, higher rates of diaphragmatic complications have been shown to significantly correlate with a younger age ( Transplantation 2002;73:228-232; Transpl Int 1998;11:281-283; Pediatr Transplant 2000;4:39-44), but diaphragmatic hernia has never been reported as a complication of liver transplantation. In this report, 2 patients who developed diaphragmatic hernia after liver transplantation are presented. The possible role of several contributing factors resulting in diaphragmatic hernia is discussed. These factors include (1) diaphragm thinness related to low weight and malnutrition, (2) direct trauma at operation (dissection and diathermy), (3) increased abdominal pressure after transplantation caused by the use of a slightly oversized liver graft, and (4) the medial positioning of the partial liver graft in the abdomen.