Reduced-size grafts--the solution for hepatic artery thrombosis after pediatric liver transplantation?

The Impact of Hepatic Artery Thrombosis on the Outcome of Pediatric Living Donor Liver Transplantations

The aim of our study was to assess risk factors for hepatic artery thrombosis (HAT) and to evaluate the impact of HAT management on long-term outcomes after pediatric living donor liver transplantation (LDLT). We retrospectively analyzed 400 patients who underwent primary LDLT between 1999 and 2020. We compared preoperative data, surgical factors, complications, and patient and graft survivals in patients with HAT (HAT Group) and without HAT (non-HAT Group). A total of 27 patients (6.75%) developed HAT. Acute liver failure, a hepatic artery (HA) anastomosis diameter below 2 mm, and intraoperative HA flow dysfunction were significantly more common in the HAT Group (p < 0.05, p = 0.02026, and p = 0.0019, respectively). In the HAT Group, 21 patients (77.8%) underwent urgent surgical revision. The incidence of biliary stenosis and retransplantation was significantly higher in the HAT Group (p = 0.00002 and p < 0.0001, respectively). Patient and graft survivals were significantly worse in the HAT Group (p < 0.05). The close monitoring of HA flow with Doppler ultrasound during the critical period of 2 to 3 weeks after LDLT and the immediate attempt of surgical revascularization may attenuate the elevated risk of biliary stenosis, graft loss, and the need for retransplantation due to HAT.

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.

Decreased Incidence of Hepatic Artery Thrombosis in Pediatric Liver Transplantation Using Technical Variant Grafts: Report of the Society of Pediatric Liver Transplantation Experience

OBJECTIVE

To evaluate risk factors for hepatic artery thrombosis (HAT) and examine the long-term outcomes of graft and patient survival after HAT in pediatric recipients of liver transplantation.

STUDY DESIGN

Using multicenter data from the Society of Pediatric Liver Transplantation, Kaplan-Meier and Cox regression analyses were performed on first-time pediatric (aged <18 years) liver transplant recipients (n = 3801) in the US and Canada between 1995 and 2016.

RESULTS

Of children undergoing their first liver transplantation, 7.4% developed HAT within the first 90 days of transplantation and, of those who were retransplanted, 20.7% developed recurrent HAT. Prolonged warm ischemia times increased the odds of developing HAT (OR, 1.11; P = .02). Adolescents aged 11-17 years (OR, 0.53; P = .03) and recipients with split, reduced, or living donor grafts had decreased odds of HAT (OR, 0.59; P < .001 compared with whole grafts). Fifty percent of children who developed HAT developed graft failure within the first 90 days of transplantation (adjusted hazard ratio, 11.87; 95% CI, 9.02-15.62) and had a significantly higher post-transplant mortality within the first 90 days after transplantation (adjusted hazard ratio, 6.18; 95% CI, 4.01-9.53).

CONCLUSIONS

These data from an international registry demonstrate poorer long-term graft and patient survival in pediatric recipients whose post-transplant course is complicated by HAT. Notably, recipients of technical variant grafts had lower odds of HAT compared with whole liver grafts.

Early Hepatic Artery Thrombosis After Pediatric Living Donor Liver Transplantation

AIM

Hepatic artery thrombosis is one of the major complications affecting patient and graft survival after liver transplantation. In this study, we analyzed the factors affecting the development of early hepatic artery thrombosis (eHAT) and its outcomes in pediatric liver transplantation.

METHODS

A total of 175 pediatric patients underwent living donor liver transplantation between January 2013 and November 2018. Factors affecting eHAT and its outcomes were examined.

RESULTS

Nine patients (5.1%) developed eHAT. In multivariate analysis, intraoperative hepatic artery revision and Roux-en-Y hepaticojejunostomy biliary reconstruction type were statistically significant (all, P < .05). Thrombectomy and reanastomosis was performed in 5 patients. Two of them were successful. In total, 3 retransplantations were performed and all of those patients are still alive.

CONCLUSION

The factors affecting eHAT are still a matter of debate. Intraoperative hepatic artery anastomosis revision and Roux-en-Y hepaticojejunostomy reconstruction were independent risk factors for development of eHAT. In the present study, the confidence interval of the variables is high, therefore exact determination of the risk factors may not be possible. Early detection and thrombectomy and reanastomosis may be the first treatment of choice to rescue the patient and graft. When it fails, retransplantation must be an alternative. The results of the present study state that at least once a day the vascular anastomosis must be examined by Doppler ultrasonography in the post-transplant first week. It must be repeated when liver enzymes increase. The patients under high risk for eHAT may be followed up closer.

Thrombosis prophylaxis in pediatric liver transplantation: A systematic review

AIM

To review current literature of thrombosis prophylaxis in pediatric liver transplantation (PLT) as thrombosis remains a critical complication.

METHODS

Studies were identified by electronic search of MEDLINE, EMBASE and Cochrane Library (CENTRAL) databases until March 2018. The search was supplemented by manually reviewing the references of included studies and the references of the main published systematic reviews on thrombosis and PLT. We excluded from this review case report, small case series, commentaries, conference abstracts, papers which describing less than 10 pediatric liver transplants/year and articles published before 1990. Two reviewers performed study selection independently, with disagreements solved through discussion and by the opinion of a third reviewer when necessary.

RESULTS

Nine retrospective studies were included in this review. The overall quality of studies was poor. A pooled analysis of results from studies was not possible due to the retrospective design and heterogeneity of included studies. We found an incidence of portal vein thrombosis (PVT) ranging from 2% to 10% in pediatric living donor liver transplantation (LDLT) and from 4% to 33% in pediatric deceased donor liver transplantation (DDLT). Hepatic artery thrombosis (HAT) was observed mostly in mixed LDLT and DDLT pediatric population with an incidence ranging from 0% to 29%. In most of the studies Doppler ultrasonography was used as a first line diagnostic screening for thrombosis. Four different surgical techniques for portal vein anastomosis were reported with similar efficacy in terms of PVT reduction. Reduced size liver transplant was associated with a low risk of both PVT (incidence 4%) and HAT (incidence 0%, P < 0.05). Similarly, aortic arterial anastomosis without graft interposition and microsurgical hepatic arterial reconstruction were associated with a significant reduced HAT incidence (6% and 0%, respectively). According to our inclusion and exclusion criteria, we did not find eligible studies that evaluated pharmacological prevention of thrombosis.

CONCLUSION

Poor quality retrospective studies show the use of tailored surgical strategies might be useful to reduce HAT and PVT after PLT; prospective studies are urgently needed.

Effects of recipient size and allograft type on pediatric liver transplantation for biliary atresia

The majority of pediatric patients with end-stage liver disease receive a transplant with a whole liver (WL) allograft. However, smaller recipients with biliary atresia (BA) may have improved outcomes with deceased donor partial liver (DDPL) or living donor allografts. This study compares the national outcomes for liver transplantation in BA, with attention to the interaction between liver allograft type and recipient size. From January 2, 2002 to December 30, 2014, 2123 pediatric patients underwent a primary liver transplant for BA. The majority of transplants (53%) were performed with a WL allograft. Utilization of a WL allograft increased from 42% of recipients weighing ≤ 7 kg to 74% of recipients weighing > 14 kg. The 1-, 5-, and 10-year graft survival in recipients weighing ≤7 kg was significantly superior for living donor liver transplantation (LDLT) (91%, 88%, 84%) and DDPL allografts (90%, 84%, 77%) compared with WL allografts (79%, 75%, 74%; P = 0.005). The 1-, 5-, and 10-year graft survival in recipients weighing >14 kg trended toward being inferior in recipients of DDPL allografts (85%, 85%, 71%) compared with WL allografts (96%, 91%, 86%; P = 0.06). Furthermore, the incidence of vascular thrombosis was highest in WL (13%) compared with LDLT (6%) and DDPL (5%) recipients ≤ 7 kg (P = 0.002). Liver retransplantation was also highest in WL (16%) compared with LDLT (9%) and DDPL (9%) recipients ≤ 7 kg (P = 0.02). In conclusion, strong consideration should be given to the use of technical variant allografts in small recipients with BA requiring liver transplantation. Liver Transplantation 23 221-233 2017 AASLD.

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.

The long-term outcome of hepatic artery thrombosis after liver transplantation in children: role of urgent revascularization

Hepatic artery thrombosis (HAT), one of the most severe complications of pediatric orthotopic liver transplantation (OLT), often compromises graft and/or child survival. Of 590 OLT performed in 516 children over a 20-year period, 45 were complicated by early HAT, during the first 2 weeks after transplantation. Systematic Doppler ultrasonographic detection of HAT allowed successful surgical revascularization in 19 instances, resulting in a 20-year graft survival rate of 77% versus 24% of cases when revascularization was not attempted or failed. A combination of surgical emergency revascularization, biliary interventional radiology, biliary surgery and/or retransplantation resulted in an 80% 20-year patient survival rate, identical to that of transplanted children who did not experience early HAT. The majority of long-term survivors with their initial graft had normal liver tests, no biliary dilation on ultrasonography and minimal or moderate fibrosis on liver histology. A failed attempt at revascularization did not significantly alter patient survival. Despite these encouraging results, for the children and their parents to overcome the entire process in terms of reoperations, repeated radiological interventions, number of hospitalizations and emotional stress, remains an ordeal of such magnitude that it justifies renewed efforts to progress in the prevention of this complication.

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.

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 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.

Survival among pediatric liver transplant recipients: impact of segmental grafts

Segmental liver transplantation with living donor (LD), reduced cadaveric (Reduced), and split cadaveric (Split) allografts has expanded the availability of size-appropriate organs for pediatric recipients. The relevance of recipient age to the selection of graft type has not been fully explored, but could offer the potential to maximize recipient outcome and donor utilization. We conducted a retrospective cohort study among children 12 years of age or less utilizing the United Network of Organ Sharing (UNOS) database. Cox proportional-hazards analysis was used to explore the association of recipient age and graft type to graft and patient survival. Among children <1 year of age and those 1 to 2 years of age, 3-year LD graft survival was superior to whole cadaveric (CAD) organs, Split grafts, and Reduced grafts (for children <1 year of age: 79.4 vs. 61.5, 66.0, and 61.1%, respectively, P = .0003; and for children 1-2 years of age: 79.2 vs 66.9, 57.1, and 63.9%, respectively, P = .02). However, in children 3 to 12 years of age, after controlling for multiple donor and recipient factors, LD grafts failed to offer a survival advantage (hazard ratio = .61; 95% confidence interval = .37-1.02) compared to CAD organs. In an adjusted analysis examining patient survival, there appeared to be minimal association between recipient age and graft type. Much of the difference in graft survival could be attributed to events in the perioperative period. In conclusion, LD liver transplantation provides improved graft survival in children 2 years of age or less.

Early graft function after pediatric liver transplantation: comparison between in situ split liver grafts and living-related liver grafts

BACKGROUND

The systematic application of living-related and cadaveric, in situ split-liver transplantation has helped to alleviate the critical shortage of suitable-sized, pediatric donors. Undoubtedly, both techniques are beneficial and advantageous; however, the superiority of either graft source has not been demonstrated directly. Because of the potential living-donor risks, we reserve the living donor as the last graft option for pediatric recipients awaiting liver transplantation. Inasmuch as no direct comparison between these two graft types has been performed, we sought to perform a comparative analysis of the functional outcomes of left lateral segmental grafts procured from these donor sources to determine whether differences do exist.

METHODS

A retrospective analysis of all liver transplants performed at a single institution between February 1984 and January 1999 was undertaken. Only pediatric (<18 years) recipients of left lateral segmental grafts procured from either living-related (LRD) or cadaveric, in situ split-liver (SLD) donors were included. A detailed analysis of preoperative, intraoperative, and postoperative variables was undertaken. Survival was estimated using the Kaplan-Meier method, and comparison of variables between groups was undertaken using the t test of Wilcoxon rank sum test.

RESULTS

There were no significant differences in the preoperative variables between the 39 recipients of SLD grafts and 34 recipients of LRD grafts. The donors did differ significantly in mean age, ABO blood group matching, and preoperative liver function testing. Postoperative liver function testing revealed significant early differences in aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, prothrombin time, and alkaline phosphatase, with grafts from LRD performing better than those from SLD. SLD grafts also had significantly longer ischemia times and a higher incidence of graft loss owing to primary nonfunction and technical complications (9 vs. 2, P<0.05). However, six of these graft losses in the SLD group were because of technical or immunologic causes, which, theoretically, should not differ between the two groups. Furthermore, these graft losses did not negatively impact early patient survival as most patients were successfully rescued with retransplantation (30-day actuarial survival, 97.1% SLD vs. 94.1% LRD, P=0.745). In the surviving grafts, the early differences in liver function variables normalized.

CONCLUSIONS

Inherent differences in both donor sources exist and account for differences seen in preoperative and intraoperative variables. Segmental grafts from LRD clearly performed better in the first week after transplantation as demonstrated by lower liver function variables and less graft loss to primary nonfunction. However, the intermediate function (7-30 days) of both grafts did not differ, and the early graft losses did not translate into patient death. Although minimal living-donor morbidity was seen in this series, the use of this donor type still carries a finite risk. We therefore will continue to use SLD as the primary graft source for pediatric patients awaiting liver transplantation.

Liver transplantation. The pediatric challenge

Successful liver transplantation in a child is often a hard-won victory, requiring all the combined expertise of a dedicated pediatric transplant team. This article outlines the considerable challenges still facing pediatric liver transplant physicians and surgeons. In looking to the future, where should priorities lie to enhance the success already achieved? First, solutions to the donor shortage must be sought aggressively by increasing the use of from split-liver transplants, judicious application of living-donor programs, and increasing the donation rate, perhaps by innovative means. The major immunologic barriers, to successful xenotransplantation make it unlikely that this option will be tenable in the near future. Second, current immunosuppression is nonspecific, toxic, and unable to be individually adjusted to the patient's immune response. The goal of achieving donor-specific tolerance will require new consideration of induction protocols. Developing a clinically applicable method to measure the recipient's immunoreactivity is of paramount importance, for future studies of new immunosuppressive strategies and to address the immediate concern of long-term over-immunosuppression. The inclusion of pediatric patients in new protocols will require the ongoing insistence of pediatric transplant investigators. Third, the current immunosuppressive drugs have a long-term morbidity and mortality of their own. These long-term effects are particularly important in children who may well have decades of exposure to these therapies. There is now some understanding of their long-term renal toxicity and the risk of malignancy. New drugs may obviate renal toxicity, whereas the risk of malignancy is inherent in any nonspecific immunosuppressive regimen. Although progress is being made in preventing and recognizing PTLD, this entity remains an important ongoing concern. The global effect of long-term immunosuppression on the child's growth, development, and intellectual potential is unknown. Of particular concern is the potential for neurotoxicity from the calcineurin inhibitors. Fourth, recurrent disease and new diseases, perhaps potentiated by immunosuppressive drugs, must be considered. Already the recurrence of autoimmune disease and cryptogenic cirrhosis have been documented in pediatric patients. Now, a new lesion, a nonspecific hepatitis, sometimes with positive autoimmune markers, that may progress to cirrhosis has been recognized. It is not known whether this entity is an unusual form of rejection, an unrecognized viral infection, or a response to immunosuppressive drugs themselves. Finally, pediatric transplant recipients, like any other children, must be protected and nourished physically and mentally if they are to fulfill their potential. After liver transplantation the child's growth, intellectual functioning, and psychologic adaptation may all require special attention from parents, teachers, and physicians alike. There is limited understanding of how the enormous physical intervention of a liver transplantation affects a child's cognitive and psychologic function as the child progresses through life. The persons caring for these children have the difficult responsibility of providing services to evaluate these essential measures of children's health over the long term and to intervene if necessary. Part of the transplant physician's our duty to protect and advocate for children is to fight for equal access to health care. In most of the developing world, economic pressures make it impossible to consider liver transplantation a health care priority. In the United States and in other countries with the medical infrastructure to support liver transplantation, however, health care professionals must strive to be sure that the policies governing candidacy for transplantation and allocation of organs are applied justly and uniformly to all children whose lives are threatened by liver disease. In the current regulatory climate that increasingly takes medical decisions out of the hands of physicians, pediatricians must be even more prepared to protect the unique and often complicated needs of children both before and after transplantation. Only in this way can the challenges of the present and the future be met.

Split liver transplantation

OBJECTIVE

This study reviews the indications, technical aspects, and experience with ex vivo and in situ split liver transplantation.

BACKGROUND

The shortage of cadaveric donor livers is the most significant factor inhibiting further application of liver transplantation for patients with end-stage liver disease. Pediatric recipients, although they represent only 15% to 20% of the liver transplant registrants, suffer the greatest from the scarcity of size-matched cadaveric organs. Split liver transplantation provides an ideal means to expand the donor pool for both children and adults.

METHODS

This review describes the evolution of split liver transplantation from reduced liver transplantation and living-related liver transplantation. The two types of split liver transplantation, ex vivo and in situ, are compared and contrasted, including the technique, selection of patients for each procedure, and the most current results.

RESULTS

Ex vivo splitting of the liver is performed on the bench after removal from the cadaver. It is usually divided into two grafts: segments 2 and 3 for children, and segments 4 to 8 for adults. Since 1990, 349 ex vivo grafts have been reported. Until recently, graft and patient survival rates have been lower and postoperative complication rates higher in ex vivo split grafts than in whole organ cadaveric transplantation. Further, the use of ex vivo split grafts has been relegated to the elective adult patient because of the high incidence of graft dysfunction (right graft) when placed in an emergent patient. Reasons for the poor function of ex vivo splits except in elective patients have focused on graft damage due to prolonged cold ischemia times and rewarming during the long benching procedure. In situ liver splitting is accomplished in a manner identical to the living donor procurement. This technique for liver splitting results in the same graft types as in the ex vivo technique. However, graft and patient survival rates reported for in situ split livers have exceeded 85% and 90%, respectively, with a lower incidence of postoperative complications, including biliary and reoperation for bleeding. These improved results have also been observed in the urgent patient.

CONCLUSION

Splitting of the cadaveric liver expands the donor pool of organs and may eliminate the need for living-related donation for children. Recent experience with the ex vivo technique, if applied to elective patients, results in patient and graft survival rates comparable to whole-organ transplantation, although postoperative complication rates are higher. In situ splitting provides two grafts of optimal quality that can be applied to the entire spectrum of transplant recipients: it is the method of choice for expanding the cadaver liver donor pool.

Long-term results of pediatric liver transplantation: an analysis of 569 transplants

OBJECTIVE

To analyze a single center's 13-year experience with 569 pediatric orthotopic liver transplants for end-stage liver disease.

SUMMARY BACKGROUND DATA

Despite advances in medical therapy, liver replacement continues to be the only definitive mode of therapy for children with end-stage liver disease. Innovative surgical techniques and improved immunosuppression have broadened the application of liver replacement for affected children. However, liver transplantation in the child remains challenging because of the scarcity of donor organs, complex surgical technical demands, and the necessity to prevent long-term complications.

METHODS

The medical records of 440 consecutive patients younger than 18 years of age undergoing orthotopic liver transplantation for end-stage liver disease from March 20, 1984, to November 15, 1997, were reviewed. Results were analyzed using Cox multivariate regression analysis to determine the statistical strength of independent associations between pretransplant covariates and patient and graft survival. Actuarial patient and graft survival rates were determined at 1, 3, 5, and 10 years. The type and incidence of posttransplant complications were determined, as was the quality of long-term allograft function. The median follow-up period was 4.1 years.

RESULTS

Biliary atresia was the most common cause (50.4%) of endstage liver disease in this patient population. The median recipient age was 2.4 years; 239 patients (54%) were younger than 3 years of age and 1 11 patients (25%) were younger than 1 year of age. There were 471 whole organs, 29 were ex vivo reduced size, 33 were living-related donor, and 36 were in situ split-liver allografts. Three hundred forty-three (78%) patients underwent a single allograft, whereas 97 patients required retransplantation; hepatic artery thrombosis was the most common indication for retransplantation (55 patients). The 1-, 3-, 5-, and 10-year actuarial patient survival rates were 82%, 80%, 78%, and 76%, respectively; allograft survival rates were 68%, 63%, 60%, and 54%. Long-term liver function remains excellent: current median follow-up values for total bilirubin and aspartate aminotransferase were 0.5 mg/dl and 54 IU/L, respectively. Cox multivariate regression analysis demonstrated that pretransplant patient age, the era of transplantation, and the number of allografts performed significantly and independently predicted patient survival rates, whereas allograft type and pretransplant diagnosis did not.

CONCLUSIONS

Liver transplantation in the pediatric patient is a durable procedure that provides excellent long-term survival. Although there have been overall improvements in patient outcome with increased experience, the effect is most pronounced for patients younger than 1 year of age. Retransplantation, although effective in a meaningful number of patients, continues to carry a progressive decrement in survival with the number of allografts performed. Use of living-related and in situ split-liver allografts has dramatically reduced waiting times for small children and has improved patient survival.

The impact of microsurgical hepatic arterial reconstruction on the outcome of liver transplantation for congenital biliary atresia

BACKGROUND

Hepatic artery thrombosis (HAT) after liver transplantation for biliary atresia (BA) is a serious complication that most often leads to retransplantation (re-OLT). The purpose of the present study was: (1) to identify risk factors associated with HAT and (2) to analyze the impact of recently introduced microsurgical hepatic arterial reconstruction (MHR) on the incidence of HAT, subsequent need for re-OLT, and patient survival.

METHODS

A retrospective review of 194 patients transplanted for BA was performed. One hundred and sixty-six patients (group 1) underwent conventional arterial reconstruction and 28 (group 2) had MHR.

RESULTS

Actuarial survival for patients with HAT was significantly worse than for patients without HAT at 1, 2, and 5 years (71%, 61%, and 57% versus 85%, 85%, and 85%, P = 0.0007). Stepwise logistic regression analysis revealed that the risk of HAT correlated best with the type of arterial reconstruction (P = 0.007) followed by pretransplant bilirubin concentration (P = 0.04) and the number of acute rejection episodes (P = 0.03). In group 1, 32 patients developed HAT (19%), and of these, 18 underwent re-OLT for HAT. No patient in group 2 developed HAT (P = 0.006 versus group 1). One-year actuarial patient survival was 81% in group 1 and 100% in group 2 (P = 0.02).

CONCLUSIONS

In OLT for BA, (1) the predominant risk factor for HAT is the technique of arterial reconstruction, and (2) MHR markedly reduces the incidence of HAT and the need for re-OLT while improving patient survival.