Optimizing the use of donated cadaver livers: analysis and policy development to increase the application of split-liver transplantation

Outcome of split-liver transplantation from pediatric donors weighing 25 kg or less

The lower limit of body weight for "splitable" liver grafts remains unknown. To examine the outcome of split-liver transplantation (SLT) from pediatric donors ≤25 kg relative to conventional graft-type liver transplantation from deceased donors under corresponding conditions, a total of 158 patients who received primary liver transplantation, including 22 SLTs from donors ≤25 kg, 46 SLTs from donors >25 kg, 76 whole-liver transplantations, and 14 reduced-liver transplantations in donors ≤25 kg between January 2018 and December 2019, were included in the study. There was no significant difference in the complications, patient survival, and graft survival between each of the latter three groups and the SLT ≤25 kg group. Pediatric End-Stage Liver Disease (PELD) score was the independent predictor of graft loss (death or retransplantation). Graft weight was the independent predictor of hepatic artery thrombosis. SLT using well-selected pediatric donors ≤25 kg is an effective strategy to increase organ availability, especially for low-body-weight recipients, compared with conventional graft type from deceased donors under the condition of corresponding donor weight without increasing morbidity and mortality.

A Novel Surgical Technique to Assure Donor and Recipient Safety: Pyloric to Segment 4 Arterial Reconstruction

Background.

Strategies to extend the pool of organs include and promote the use of segmental liver grafts. While performing a living donor left lateral segment (LLS) liver transplant and in split procedures, the hepatic artery´s division becomes critical when a dominant segment 4 artery (S4A) emerges from the left hepatic artery (LHA). We aim to describe a novel technique that consists of performing microsurgical reconstruction from the pyloric artery (PA) to S4A.

Case Reports.

A 45-y-old living donor was evaluated to use his LLS as a graft for a pediatric recipient. During the procedure, a dominant S4A born from the LHA was dissected. To obtain an appropriate LHA length and diameter for the recipient, it was necessary to transect it. An extended right lobe split graft was used in a 61-y-old patient. The S4A born from LHA had to be sectioned during the split procedure. In both cases, segment 4 remained incompletely perfused. The PA was dissected with enough length to be rotated, to perform a microsurgical anastomosis to the S4A, recovering parenchyma’s color and Doppler signal while vascular permeability was demonstrated using CT scan. There was no biliary or cut surface complication.

Conclusions.

PA to S4A reconstruction is a simple and novel technique that can be used for LLS and extended right lobe split graft and might contribute to increase donor selection and reduce living donor and recipient S4A-related complications.

Prioritization for liver transplantation using the MELD score in Chile: Inequities generated by MELD exceptions.: A collaboration between the Chilean Liver Transplant Programs, the Public Health Institute and the National Transplant Coordinator

INTRODUCTION AND AIM

The MELD score has been established as an efficient and rigorous prioritization system for liver transplant (LT). Our study aimed to evaluate the effectiveness of the MELD score as a system for prioritization for LT, in terms of decreasing the dropout rate in the waiting list and maintaining an adequate survival post-LT in Chile.

MATERIALS AND METHODS

We analyzed the Chilean Public Health Institute liver transplant registry of candidates listed from October 15th 2011 to December 31st 2014. We included adult candidates (>15 years old) listed for elective cadaveric LT with a MELD score of 15 or higher. Statistical analysis included survival curves (Kaplan-Meier), log-rank statistics and multivariate logistic regression.

RESULTS

420 candidates were analyzed. Mean age was 53.6±11.8 years, and 244 were men (58%). Causes of LT included: Liver cirrhosis without exceptions (HC) 177 (66.4%); hepatocellular carcinoma (HCC) 111 (26.4%); cirrhosis with non-HCC exceptions 102 (24.3%) and non-cirrhotic candidates 30 (7.2%). LT rate was 43.2%. The dropout rate was 37.6% at 1-year. Even though the LT rate was higher, the annual dropout rate was significantly higher in cirrhotic candidates (without exceptions) compared with cirrhotics with HCC, and non-HCC exceptions plus non-cirrhotic candidates (47.9%; 37.2% and 24.2%, respectively, with p=0.004). Post-LT survival was 84% per year, with no significant differences between the three groups (p=0.95).

CONCLUSION

Prioritization for LT using the MELD score system has not decreased the dropout rate in Chile (persistent low donor's rate). Exceptions generate inequities in dropout rate, disadvantaging patients without exceptions.

An Empirically Informed Analysis of the Ethical Issues Surrounding Split Liver Transplantation in the United Kingdom

Surgical advances have allowed for the development of split liver transplantation, providing two recipients with the opportunity to potentially benefit from one donated liver by splitting the liver into two usable parts. Although current data suggest that the splitting of livers provides overall benefit to the liver-recipient population, relatively low numbers of livers are actually split in the United Kingdom. This article addresses the question of whether ethical concerns are posing an unnecessary barrier to further increasing the number of life-saving transplantations. Recognizing that an important aspect of exploring these concerns is gaining insight into how transplant staff and patients regard splitting livers, the article presents the findings of a qualitative study examining the views of senior transplant staff and liver transplant patients in the UK and uses these to inform a commentary on the ethical issues relating to split liver transplantation.

Fifteen years and 382 extended right grafts from in situ split livers in a multicenter study: Are these still extended criteria liver grafts?

In situ split liver extended right grafts (SL-ERGs) are still considered marginal grafts. Our aim was to verify this statement at the present time. From 1997 to 2011, a multicenter, retrospective study based on a prospective database was performed at 9 liver transplantation (LT) centers in northern Italy; it included 382 in situ SL-ERG transplants in adults. There were 358 primary LTs and 24 retransplantations (RETXs). The 1-, 3-, and 5-year overall graft survival rate for LT with in situ SL-ERGs were 73.5%, 63.3%, and 60.7%, respectively, from 1997 to 2004 and 83.5%, 80.3%, and 80.3%, respectively, thereafter (P=0.0001). A shorter total ischemia time and fewer RETX grafts were the main differences between the characteristics of the 2 periods. From 1997 to 2011, the 1-, 3-, and 5-year graft survival rates showed a significant difference between the 358 primary LT in situ SL-ERGs and the 24 RETX in situ SL-ERGs (P<0.001). In a multivariate analysis, the main prognostic factor for 60-day graft survival was a total ischemia time<8 hours for the 358 primary in situ SL-ERGs. From 2005 to 2011, in 2473 LTs, the 5-year graft survival for 184 in situ SL-ERGs and 2289 whole grafts was 75% and 80% (P=0.3), respectively. Univariate and multivariate studies alike failed to indicate that the type of graft was a prognostic factor for graft survival. A donor age>60 years, RETX grafts, and urgency were the main prognostic factors for failure for all of the grafts. Although caution should be taken regarding the choice of appropriate donors, in situ SL-ERGs should no longer be considered marginal grafts for experienced LT centers. SL-ERGs should not be used in RETX settings, and when SL-ERGs are used as primary grafts, the total ischemia time should be less than 8 hours.

Impact of the current organ allocation system for deceased donor liver transplantation on the outcomes of pediatric recipients: a single center experience in Japan

PURPOSE

The aim of this study was to analyze the outcomes of children added to the waiting list for deceased donor liver transplantation (DDLT) and the results of DDLT in a single Japanese center.

METHODS

Forty-seven children were listed on the organ allocation system for DDLT. The priority points related to the medical status of each patient were evaluated and stratified into four categories; 10, 8, 6, and 3 points. The clinical data were collected from the medical records, and the outcomes were analyzed.

RESULTS

There were 10 priority points in 25 patients, 6 points in 13 and 3 points in 9. Ten recipients (21.3 %); 7 patients with 10 points and 3 patients with 6 points, underwent DDLT. Seven out of the 10 recipients received split/reduced liver grafts. The surgical complications consisted of biliary stricture, hepatic venous outflow obstruction, intraabdominal abscess and intraabdominal bleeding. Two recipients, who were critically-ill before DDLT, died due to sepsis. The one-year graft survival rate was 70.0 %, with a median follow-up period of 6.4 months.

CONCLUSION

The initial experience with pediatric DDLT in our series was satisfactory. Split LT of deceased donor organs may have the potential to resolve the serious organ shortage in Japan.

Feasibility of split liver transplantation for 2 adults in the model of end-stage liver disease era

OBJECTIVE

To examine the results of split liver transplantation for 2 adults in the model of end-stage liver disease (MELD) era.

BACKGROUND

In the MELD era, liver allografts are first allocated to recipients with the highest MELD scores. However, the application of split liver transplantation for 2 adults in urgent condition has doubled and has become a matter of concern.

METHODS

Twenty-one deceased liver grafts were split into full right and full left lobes for 42 adult recipients. One of the hemiliver grafts was allocated to the recipient with the highest MELD score in the waiting list. The results of split liver transplantation were examined and compared with those of living donor liver transplantation.

RESULTS

Among 42 recipients, 24 (57.1%) had MELD scores higher than 20. The median (interquartile) MELD score for the recipients with split liver transplantation was 22 (15-30), which was higher than that for the recipients with living donor liver transplantation (P < 0.001). The 1-, 3-, and 5-year survival rates for split liver transplantation were comparable with those of living donor transplantation (P = 0.489). Nevertheless, 10 of 42 split liver recipients died within 3 months after transplantation. By receiver operating characteristic curve analysis, the safe graft-recipient weight ratio was better more than 1% to avoid early patient death for split liver transplantation.

CONCLUSIONS

Although most of the recipients with split liver transplantation had high MELD scores, the results were comparable with those of living donor liver transplantation. Split liver transplantation for 2 adults is still feasible in the MELD era.

Split liver transplantation using extended right grafts: the natural history of segment 4 and its impact on early postoperative outcomes

Split liver transplantation (SLT) using extended right grafts is associated with complications related to ischemia of hepatic segment 4 (S4), and these complications are associated with poor outcomes. We retrospectively analyzed 36 SLT recipients so that we could assess the association of radiological, biological, and clinical features with S4 ischemia. The overall survival rates were 84.2%, 84.2%, and 77.7% at 1, 3, and 5 years, respectively. The recipients were mostly male (24/36 or 67%) and had a median age of 52 years (range = 13-63 years), a median body mass index of 22.9 kg/m(2) (range = 17.3-29.8 kg/m(2) ), and a median graft-to-recipient weight ratio of 1.3% (range = 0.9%-1.9%). S4-related complications were diagnosed in 22% of the patients (8/36) with a median delay of 22 days (range = 10-30 days). Secondary arterial complications were seen in 3 of these patients and led to significantly decreased graft survival in comparison with the graft survival of patients without complications (50.0% versus 85.6%, P = 0.017). Patients developing S4-related complications had significantly elevated aspartate aminotransferase (AST) levels (>1000 IU/L) on postoperative day (POD) 1 and elevated gamma-glutamyl transpeptidase (GGT) levels (>300 IU/L) on PODs 7 and 10 (P < 0.05). These AST and GGT elevations conferred a significantly high risk of developing these complications (odds ratio = 42, 95% confidence interval = 4-475, P < 0.05). The ischemic volume of S4 was extremely variable (0%-95%) and did not correlate with S4-related complications. In conclusion, our results suggest that S4-related complications are risk factors for worse graft survival, and the development of these complications can be anticipated by the early identification of a specific biological profile and a routine radiological examination.

Outcomes in partial liver transplantation: deceased donor split-liver vs. live donor liver transplantation

BACKGROUND

Organ shortage has resulted in greater emphasis on partial liver transplantation (PLT) as an alternative to whole-organ liver transplantation.

METHODS

This study was conducted to assess outcomes in PLT and to compare outcomes of deceased donor split-liver transplantation (DD-SLT) and live donor liver transplantation (LDLT) in adults transplanted in the USA using data reported to the United Network for Organ Sharing in the era of Model for End-stage Liver Disease (MELD) scores.

RESULTS

Between 2002 and 2009, 2272 PLTs were performed in the USA; these represented 5.3% of all liver transplants carried out in the country and included 557 (24.5%) DD-SLT and 1715 LDLT (75.5%) procedures. The most significant differences between the DD-SLT and LDLT groups related to mean MELD scores, which were lower in LDLT recipients (14.5 vs. 20.9; P < 0.001), mean recipient age, which was lower in the LDLT group (50.7 years vs. 52.8 years; P < 0.001), and mean donor age, which was lower in the DD-SLT group (23.0 years vs. 37.3 years; P < 0.001). Allograft survival was comparable between the two groups (P= 0.438), but patient survival after LDLT was better (P= 0.04). In Cox regression analysis, LDLT was associated with better allograft (hazards ratio [HR]= 0.7, 95% confidence interval [CI] 0.630-0.791; P < 0.0001) and patient (HR = 0.6, 95% CI 0.558-0.644; P < 0.0001) survival than DD-SLT.

CONCLUSIONS

Partial liver transplantation represents a potentially underutilized resource in the USA. Despite the differences in donor and recipient characteristics, LDLT is associated with better allograft and patient survival than DD-SLT. A different allocation system for DD-SLT allografts that takes into consideration cold ischaemia time and recipient MELD score should be considered.

Where are we today in split liver transplantation?

PURPOSE OF REVIEW

Results of surgical innovations using partial liver grafts from deceased donors have improved the availability of transplantable organs. However, current data on outcomes after split liver transplantation (SLT) are conflicting. This article reviews the current state of SLT, focusing on long-term outcomes and predictors for patient and graft survival after SLT.

RECENT FINDINGS

The conventional SLT has been proven to be a durable life-saving procedure. Early results for full left-right SLT for two adults are promising but this technique had not showed efficacy for wide application. Predictors of diminished patient survival after SLT included the use of split grafts in critically ill recipients (model for end-stage liver disease score >30), retransplant patients, cold ischemia time more than 10 h, and the performance of SLT in low-volume liver transplant centers.

SUMMARY

Conventional SLT performed in specialized centers resulted in long-term survival outcomes comparable with whole-organ liver transplantation. Full left-right SLT for two adults remains experimental. Splitting of the liver is an effective approach to expand the donor pool and remains an untapped resource for patients in need of liver transplantation. Split graft-to-recipient pairing is crucial for optimal organ allocation and survival outcomes after liver transplantation.

Pediatric liver transplantation

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

Split-liver transplantation: an underused resource in liver transplantation

Split-liver transplantation is an efficient tool to increase the number of liver grafts available for transplantation. More than 15 years after its introduction only the classical splitting technique has reached broad application. Consequently children are benefiting most from this possibility. Full-right full-left splitting for two adult recipients has been shown to work but is hampered mainly by the dangers of small-for-size transplantation. A solution to this last problem would completely change the scope of split-liver transplantation. Organ allocation systems and collaboration between centers play a crucial role in the chances to let suitable patients profit from this valuable source of extra grafts.

Factors affecting graft survival after adult/child split-liver transplantation: analysis of the UNOS/OPTN data base

When considering advocacy of split-liver transplantation, it is important to understand whether comparable outcomes can be achieved. The goal of this study was to identify donor and transplant characteristics predictive of comparable outcomes by risk factor analysis. Using the United Network for Organ Sharing/ Organ Procurement and Transplantation Network data base between January 1996 and May 2006, first time adult/child split cases (568 adults, 508 children) were examined. In multivariate analysis, recipient medical condition (hospitalization), status 1 assignment, ABO incompatibility, donor age (>40 years), donor body weight (< or = 40 kg), calculated whole graft volume to recipient body weight ratio (cGRWR < or = 1.5%) and no sharing between centers were significant risk factors in adult recipients. Recipient diagnosis of tumor, dialysis prior to transplant, recipient body weight (< or = 6 kg), donor age (>30 years), donor history of cardiac arrest after declaration of death and cold ischemia time (CIT > 6 h) increased the risk of graft failure in pediatric recipients. The livers from young donors showed comparable outcomes to whole deceased liver transplantation (LT) when other transplant-related risk factors were minimized in adult recipients. Reducing CIT is important to obtain comparable outcomes to living donor LT in pediatric recipients.

Does middle hepatic vein omission in a right split graft affect the outcome of liver transplantation? A comparative study of right split livers with and without the middle hepatic vein

Preservation of the middle hepatic vein (MHV) for a right split liver transplantation (SLT) in an adult recipient is still controversial. The aim of this study was to evaluate the graft and patient outcomes after liver transplantation (LT) using a right split graft, according to the type of venous drainage. From February 2000 to May 2006, 33 patients received 34 cadaveric right split liver grafts. According to the type of recipient pairs (adult/adult or adult/child), the right liver graft was deprived of the MHV or not. The first group (GI, n = 15) included grafts with only the right hepatic vein (RHV) outflow, the second (GII, n = 18) included grafts with both right and MHV outflows. The 2 groups were similar for patient demographics, initial liver disease, and donor characteristics. In GI and GII, graft-to-recipient-weight ratio (GRWR) was 1.2 +/- 0% and 1.6 +/- 0.3% (P < 0.05), and cold ischemia time was 10 hours 55 minutes +/- 2 hours 49 minutes and 10 hours 47 minutes +/- 3 hours 32 minutes, respectively (P = not significant). Postoperative death occurred in 1 patient in each group. Vascular complications included anastomotic strictures: 2 portal vein (PV), 1 hepatic artery (HA), and 1 RHV anastomotic strictures; all in GI. Biliary complications occurred in 20% and 22% of the patients, in GI and GII, respectively (P = not significant). There were no differences between both groups regarding postoperative outcome and blood tests at day 1-15 except for a significantly higher cholestasis in GI. At 1 and 3 yr, patient survival was 94% for both groups and graft survival was 93% for GI and 90% for GII (P = not significant). In conclusion, our results suggest that adult right SLT without the MHV is safe and associated with similar long-term results as compared with those of the right graft including the MHV, despite that early liver function recovered more slowly. Technical refinements in outflow drainage should be evaluated in selected cases.

Combination of Extended Donor Criteria and Changes in the Model for End-Stage Liver Disease Score Predict Patient Survival and Primary Dysfunction in Liver Transplantation: A Retrospective Analysis

BACKGROUND

The purpose of this study was to analyze the impact of extended donor criteria (EDC) and of changes in the Model for End-Stage Liver Disease (MELD) score while waiting for liver-transplantation (Delta-MELD) on patient survival and initial graft function.

METHODS

We included 386 consecutive patients with end-stage liver disease who underwent orthotopic liver transplantation at the Medical University Vienna between 1997 and 2003. Primary outcome was patient survival and secondary outcome was initial graft function. EDC included: age >60 years, >4 days intensive medical care, cold ischemia time >10 hr, need for noradrenalin >0.2 microg/kg/min or doputamin >6 microg/kg/min, a donor peak serum sodium >155 mEq/L, a donor serum creatinine >1.2 mg/100 mL, and a body mass index >30.

RESULTS

Delta-MELD was significantly higher in the nonsurvivor population (P=0.01) and EDC showed a significant influence on initial graft function (P=0.01). Worsening in either Delta-MELD or the presence of at least two EDC was not associated with an increased risk of primary graft dysfunction and death. Worsening in Delta-MELD and the presence of at least two EDC was significantly associated with primary graft dysfunction (P=0.01) and death (P=0.008).

CONCLUSION

The combination of a liver recipient with worsening Delta-MELD and a potential donor with at least two EDC should be avoided.

Use of split-liver allografts does not impair pediatric recipient growth

The use of split-liver (SL) allografts continues to be an excellent option for many pediatric recipients. Patient and graft survival with this graft type are comparable to patient and graft survival with whole organ grafts. Quality-of-life issues, specifically growth, for SL recipients have not been compared to those of recipients of more conventional whole-organ recipients. Pediatric recipients of SL and whole allografts at 2 institutions were identified. Height, z score, and delta z score were calculated for all recipients for each year after transplant. Between 1995 and 2004, 201 pediatric liver transplants were analyzed. Data were collected on 39 split-graft recipients and 36 whole-size recipients. Only subjects 3 years or younger were included in the study. Growth retardation was present in all recipients at transplant. Height z score post split and whole-size transplant were not statistically different at 1- (P = 0.65), 2- (P = 0.13), and 3-year (P = 0.32) anniversaries, respectively. Catch-up growth was present only in recipients of split grafts. In conclusion, the use of split grafts as opposed to whole-size grafts revealed no significant differences in terms of linear growth. Our report indicates that split-liver transplantation does not impair recipient growth.

Feasibility and limits of split liver transplantation from pediatric donors: an italian multicenter experience

OBJECTIVE

To report the results of a multicenter experience of split liver transplantation (SLT) with pediatric donors.

SUMMARY BACKGROUND DATA

There are no reports in the literature regarding pediatric liver splitting; further; the use of donors weighing <40 kg for SLT is currently not recommended.

METHODS

From 1997 to 2004, 43 conventional split liver procedures from donors aged <15 years were performed. Nineteen donors weighing < or =40 kg and 24 weighing >40 kg were used. Dimensional matching was based on donor-to-recipient weight ratio (DRWR) for left lateral segment (LLS) and on estimated graft-to-recipient weight ratio (eGRWR) for extended right grafts (ERG). In 3 cases, no recipient was found for an ERG. The celiac trunk was retained with the LLS in all but 1 case. Forty LLSs were transplanted into 39 children, while 39 ERGs were transplanted into 11 children and 28 adults.

RESULTS

Two-year patient and graft survival rates were not significantly different between recipients of donors < or =40 kg and >40 kg, between pediatric and adult recipients, and between recipients of LLSs and ERGs. Vascular complication rates were 12% in the < or =40 kg donor group and 6% in the >40 kg donor group (P = not significant). There were no differences in the incidence of other complications. Donor ICU stay >3 days and the use of an interposition arterial graft were associated with an increased risk of graft loss and arterial complications, respectively.

CONCLUSIONS

Splitting of pediatric liver grafts is an effective strategy to increase organ availability, but a cautious evaluation of the use of donors < or =40 kg is necessary. Prolonged donor ICU stay is associated with poorer outcomes. The maintenance of the celiac trunk with LLS does not seem detrimental for right-sided grafts, whereas the use of interposition grafts for arterial reconstruction should be avoided.

Surgical injuries of postmortem donor livers: incidence and impact on outcome after adult liver transplantation

The exact frequency and clinical consequences of surgical hepatic injuries during organ procurement are unknown. We analyzed the incidence, risk factors, and clinical outcome of surgical injuries in 241 adult liver grafts. Hepatic injuries were categorized as parenchymal, vascular, or biliary. Outcome variables were bleeding complications, hepatic artery thrombosis (HAT), and graft survival. In 82 livers (34%), 96 injuries were detected. Most injuries were minor, but clinically relevant injuries were detected in 6.6% (16/241) of the livers. Fifty (21%) liver grafts had some degree of parenchymal or capsular injury, 40 (17%) had vascular injury, and 6 (2%) had an injury to the bile duct. Procurement region was the only risk factor significantly associated with surgical injury. The rate of hepatic artery injury was significantly higher in livers with aberrant arterial anatomy. Bleeding complications were found in 18% of patients who received livers with a parenchymal or capsular injury in contrast to 9% without parenchymal injury (P = 0.065). HAT was found in 23% of the patients who received a liver with arterial injury compared to 4% without arterial injury (P = 0.001). Overall graft survival rates were not significantly different for grafts with or without anatomical injury. In conclusion, surgical injuries of donor livers are an underestimated problem in liver transplantation and can be observed in about one-third of all cases. Clinically relevant injuries are detected in 6.6% of all liver grafts. Arterial injuries are associated with an increased risk of HAT.

Impact of dialysis and older age on survival after liver transplantation

Because creatinine is heavily weighed in the MELD (model for end-stage liver disease) score, we sought to determine the impact of MELD-based organ allocation on outcomes after transplantation in the pre- and post-MELD eras, focusing on recipients over age 65 on dialysis prior to transplant. A total of 20 196 patients from the UNOS database were analyzed. Comparing the pre-MELD to MELD era, there was a 41% increase in patients on dialysis (p<0.0001), and a 117% increase in combined liver/kidney transplants (p<0.0001). In the pre-MELD era, 1-year patient survival in recipients greater and less than age 65 on dialysis who received liver transplant alone was 56.8% and 76.4%, respectively (p=0.13). In the MELD era these rates were 50.7% and 77.8% (p=0.04). In the pre-MELD era, 1-year patient survival in recipients greater and less than age 65 on dialysis who underwent combined liver/kidney transplantation was 25.0% and 83.2%, respectively (p=0.0002). In the MELD era, these rates were 67.0% and 82.5% (p=0.18). In conclusion, a greater proportion of patients in the MELD era are on dialysis prior to transplant, and more receive combined liver/kidney transplants compared with the pre-MELD era. Candidates over age 65 who are on dialysis at the time of transplant have decreased survival after isolated liver transplantation.

Extended right split liver graft for primary transplantation in children and adults

Skepticism remains about the use of the extended right (ER) split graft (segments I, IV-VIII) for adult liver transplantation. We analyzed the results of primary liver transplantation performed with an ER graft in adult and in pediatric recipients. At our Institution, between October 1997 and June 2005, 32 primary liver transplantations with an ER graft were performed in 22 adult and 10 pediatric recipients. All the splitting procedures were performed in situ. Actuarial patient and graft survival among the adult recipients of the ER graft were 100% and 100% at 1 year, and 94% and 94% at 5 years. In the pediatric recipients, patient and graft survival were 90% and 79% both at 1 and 5 years. No hepatic artery thrombosis (HAT) occurred in the adult group, while in the pediatric recipients HAT occurred in two cases. A higher biliary morbidity occurred in the ER graft group when compared with the whole size graft 34% versus 13% (P = 0.03). However, this did not affect patient and graft survival. The results of this study may represent a further argument in favor of extensive splitting of all suitable grafts.

Live donor liver transplantation

With ever-increasing demand for liver replacement, supply of organs is the limiting factor and a significant number of patients die while waiting. Live donor liver transplantation has emerged as an important option for many patients, particularly small pediatric patients and those adults that are disadvantaged by the current deceased donor allocation system. Ideally there would be no need to subject perfectly healthy people in the prime of their lives to a potentially life-threatening operation to procure transplantable organs. Donor safety is imperative and cannot be compromised regardless of the implication for the intended recipient. The evolution of split liver transplantation is the basis upon which live donor transplantation has become possible. The live donor procedures are considerably more complex than whole organ decreased donor transplantation and there are unique considerations involved in the assessment of any specific recipient and donor. Donor selection and evaluation have become highly specialized. The critical issue of size matching is determined by both the actual size of the donor graft and the recipient as well as the degree of recipient portal hypertension. The outcomes after live donor liver transplantation have been at least comparable to those of deceased donor transplantation. Nevertheless, all efforts should be made to improve deceased donor donation so as to minimize the need for live donors. Transplant physicians, particularly surgeons, must take responsibility for regulating and overseeing these procedures.

Retrieval of abdominal organs for transplantation

BACKGROUND

Organ retrieval and donor management are not yet standardized. Different transplant centres apply various techniques, such as single or dual organ perfusion, dissection in the cold or warm, and single or en bloc organ removal. These different approaches may cause inconvenience, especially when more than one organ retrieval team is involved.

METHODS

Cochrane Library, Medline and PubMed were searched for publications on multiorgan donor/donation, retrieval technique and procurement. Levels of evidence and grades of recommendation were evaluated based on current advice from the Oxford Centre for Evidence-Based Medicine.

RESULTS

Multiorgan donation itself does not compromise the outcome of individual organ transplants. Dissection of abdominal organs for transplantation is best performed after cold perfusion. Abdominal organs should be removed rapidly, en bloc, and separated during back-table dissection in the cold, particularly if pancreas or intestine is included. Perfusion itself should be carried out after single cannulation of the aorta with an increased pressure.

CONCLUSION

Although the literature on organ retrieval is extensive, the level of evidence provided is mainly low. Nevertheless, optimized donor treatment and organ retrieval should increase the number and quality of cadaveric donor organs and improve graft function and survival.

Surgical experience in splitting donor liver into left lateral and right extended lobes

AIM: To outline the surgical experience with donor liver splitting in split liver transplantation.

METHODS: From March 1 to September 1 in 2004, 10 donor livers were split ex situ into a left lateral lobe (segments II and III) and a right extended lobe (segments I, IV - VIII) in Medical School of Hannover, and thereafter split liver transplantation was performed successfully in 19 cases. The average age, weight and ICU staying period of the donors were 32.7 years (15 - 51 years), 64.5 kg (45 - 75 kg) and 2.4 d (1 - 8 d) respectively.

RESULTS: The average weight of the whole graft and the left lateral lobe was 1 322.6 g (956 - 1 665 g) and 281.8 g (198 - 373 g) respectively, and the average ratio of left lateral lobe to the whole graft was 0.215 (0.178 - 0.274). The average graft to recipient weight ratio (GRWR) of the left lateral lobe and the right extended lobe reached 2.44% (1.22 - 5.41%) and 1.73% (1.31 - 2.30%) respectively. On average it took approximately 105 min (85 - 135 min) to split the donor liver. Five donor organs showed anatomic variation including the left hepatic vein variation in two cases, the left hepatic artery variation in two cases and the bile duct variation in one case.

CONCLUSION: Split liver transplantation has become a mature surgical technique to expand the donor pool with promising results. In the process of graft splitting, close attention needs to be paid to potential anatomic variations, especially to variations of the left hepatic vein, the left hepatic artery, and the bile duct.

Split-liver transplantation with pediatric donors: a multicenter experience

BACKGROUND

Outcomes of split-liver transplantation (SLT) with pediatric donors have never been specifically reported.

METHODS

A prospective multicenter study on SLT using donors younger than 15 years was conducted. Thirty-nine split-liver procedures generating a left lateral segment (LLS) and an extended right graft (ERG) were performed. In three cases, no recipient was found for ERG. In all but one case, the celiac trunk was maintained with LLS. Data were available for 67 grafts (90% of the total): 38 LLSs and 9 ERGs transplanted into 46 children and 20 ERGs transplanted into 20 adults. Sixty-two (93%) grafts were used for primary transplants and five (7%) for retransplantation. SLT were performed with 15 donors 10 years of age and less and with 24 between 11 and 15 years.

RESULTS

Median follow-up was 24 months. Two-year patient and graft survival were 87% and 82%. Patient and graft survivals were not significantly different between pediatric and adult recipients, between recipients from donors 10 years of age and less and those between 11 and 15 years, and between recipients of LLS and ERG. Arterial complications occurred in 6% of cases (8% in the < or = 10 year donors group, 5% in the 11-15 year donors group). The incidence of other complications was similar between groups.

CONCLUSIONS

SLT with pediatric donors, even younger than 10 years, provided results comparable with those achievable using adult donors. The similar incidence of arterial complications among patients receiving LLS or ERG suggests that maintenance of the celiac trunk with LLS is not detrimental for right-sided grafts.

Split-liver transplantation: results of statewide usage of the right trisegmental graft

Split-liver transplantation (SLT) effectively expands the cadaveric donor pool for children. The remaining right trisegmental (RTS) graft can be transplanted into adults. Limited information exists regarding the outcomes of RTS allografts. Sixty-five RTS graft recipients from five adult transplant programs in Texas were identified. Donor and recipient information were analyzed retrospectively. Most livers (75%) were originally allocated to pediatric recipients. Liver splitting occurred via the in situ (72%) and ex situ (28%) techniques. Arterial reconstruction of RTS grafts was common (52%). Patient and graft survival at 3 months were comparable for the in situ and ex situ techniques (p = 0.2). Cox regression showed only in situ splitting to be a predictor of outcome longer than 3 months posttransplant. Sharing of grafts between centers was frequent (37% of total). One-year patient and allograft survival (87.1% and 85.4%) were excellent with no cases of primary nonfunction. SLT consistently generates two functional liver allografts with excellent recipient survival. In situ splitting of the liver is the preferred technique. Decreased survival is observed with RTS graft use in higher risk recipients. Broader application of SLT with increased sharing is feasible and safely expands the number of liver allografts that can be transplanted.

Impact of donor age and year of transplant on graft survival in liver transplant recipients with chronic hepatitis C

Studies suggest donor age and year of transplantation are associated with low graft survival in liver transplant recipients with hepatitis C. We sought to determine if advanced donor age and recent year of transplantation are associated with graft survival in hepatitis C recipients and to determine if the effect of donor age on graft survival is specific to hepatitis C. We analyzed the United Network for Organ Sharing liver transplant database from 1994 to 2002. Six thousand four hundred and four subjects transplanted for end-stage liver disease from chronic hepatitis C met our criteria. One-year graft survival in hepatitis C recipients with organs from donors <40 years old and >or=60 years old was 84% and 73%, p = 0.003, respectively. These rates in recipients with cholestatic liver disease and alcoholic liver disease were 85% and 82%, respectively, p = 0.11 and 82% and 78%, respectively, p = 0.14. Three-year graft survival in hepatitis C recipients transplanted from 1994 to 1995 and 1996 to 1999 was 67% and 69%, respectively, p = 0.10. Graft survival in hepatitis C recipients has not declined in recent years. Older donor age is associated with lower short-term graft survival in recipients with hepatitis C, but not in recipients with cholestatic or alcoholic liver disease.

Studies of Pediatric Liver Transplantation: 2002 update. An overview of demographics, indications, timing, and immunosuppressive practices in pediatric liver transplantation in the United States and Canada

Studies of Pediatric Liver Transplantation (SPLIT) was initiated in 1995 for the purpose of collecting comprehensive data from children undergoing liver transplantation. As of May 31, 2002, 1761 children were registered in SPLIT from 38 participating centers in the United States and Canada. This report focuses on the demographics, primary diagnoses, clinical indications for transplant, and probability of obtaining liver transplantation for the 1187 children receiving a liver transplant after registration in SPLIT. Demographic information is also provided for the 1092 children who received their first ever liver transplantation. For this cohort, we also describe immunosuppressive practices at the time of transplant, and how the use of different medications changes with time.

Stem cell therapy of the liver--fusion or fiction?

Various stem cell populations have been described in distinct models of liver regeneration. This review provides an overview of these different stem cell populations aimed at unifying diverse views of liver stem cell biology. Embryonic stem cells, hemopoietic stem cells, mesenchymal stem cells, liver-derived hepatic stem cells, bone marrow-derived hepatic stem cells, and mature hepatocytes (as cells with stemlike properties) are considered separately. In so doing, we seek to clarify the nomenclature of putative liver stem cell types. Experiments that address the question of cellular fusion versus transdifferentiation as explanations for observed liver regeneration are highlighted. This review concludes with a series of open questions that should be addressed in the context of clinical liver disease before attempts at human therapeutic interventions.

Split-liver transplantation in the United States: outcomes of a national survey

OBJECTIVE

Assess application and outcomes of split-liver transplantation within the United States.

SUMMARY BACKGROUND DATA

While a theoretically attractive mechanism to increase cadaver organ supply, split-liver transplantation has been infrequently applied. The American Society of Transplant Surgeons, in an attempt to gather preliminary data on split-liver transplantation, performed a data protected survey of transplant centers participating in the U.S. Scientific Registry for Transplant Recipients.

METHODS

Between April 2000 and May 2001, 89 surgical teams were surveyed. Elicited data included graft type, recipient status, procurement method, graft sharing, graft outcomes, recipient outcomes, and experience with cadaver, whole-organ transplantation.

RESULTS

Eighty-three surgical teams reported data on 207 left lateral segment, 152 right trisegment, 15 left lobe, and 13 right lobe grafts. The split procedure was performed ex vivo in 54% and in situ in 46% of grafts. Complications were frequent in all graft types with biliary and vascular complications equally distributed between grafts procured by either technique. Primary nonfunction, graft failure, and recipient death correlated with transplant status.

CONCLUSIONS

Split-liver transplantation has been principally applied to adult-child pairs with at least one recipient critically ill. Biliary and vascular complications account for the majority of morbidity in grafts procured by either split technique with graft failure and recipient death observed more frequently in critically ill recipients. Enhanced utilization and improved results may be possible through improved information sharing and modification of allocation criteria.

Current status of liver transplantation in children

There are two critical issues on opposite ends of the timeline for patients who are eligible for liver transplantation. On the one hand, the crisis in the cadaveric organ supply makes surviving to transplant ever more risky. On the other hand, patients who receive successful transplants face the consequences of long-term immunosuppression and its potentially life-threatening complications. The donor shortage is forcing difficult decisions that affect all patients who await liver transplantation. It is important to scrutinize carefully the results of all policies that govern allocation and the ethics of the solutions we advocate to ensure that no patient subgroup is being at a disadvantage. Current immunosuppression practices are being challenged by an increasing understanding of the immunologic events triggered by the allograft and the goal to free patients from consequences of a lifetime of immunosuppression. Clinicians can expect, and perhaps require, that new immunosuppressive protocols will address how the planned intervention might be expected to advance the understanding of tolerance mechanisms. As knowledge increases, clinicians can anticipate innovative new immunosuppressive proposals. Calcineurin and steroid-free induction, the use of donor-derived bone marrow infusion, recipient pretreatment, costimulatory blockade, and new antibody induction approaches are all being proposed--often in combination--for clinical trials. Researchers face additional challenges in defining endpoints if the goal is not just the short-term reduction in rejection but the minimization, and eventual discontinuation, of immunosuppressive drugs while maintaining excellent long-term graft function. How much "failure" will be accepted and how will it be defined? How will clinicians interpret liver biopsies if they begin to accept that some lymphocytic infiltrates may be beneficial mediators of the ongoing immune activation necessary for the maintenance of tolerance? How will they adjust immunosuppression practices to the dynamic processes in the immune response that maintain tolerance? Remarkable short-term successes in providing transplants for thousands of children with liver failure have brought these challenges into sharp focus. Clinicians must seek to move the life-giving science of transplantation toward a new goal: providing long lifetimes of excellent graft function with minimal toxicity from immunosuppressive drugs and the hope of freedom from immunosuppression altogether. Pediatric liver recipients, whose grafts have inherent tolerogenic potential and for whom we can anticipate decades of life after transplant, may prove to be an ideal study population to further these goals.

One hundred in situ split-liver transplantations: a single-center experience

OBJECTIVE

To identify predictors of graft and recipient survival from a single-institution series of in situ split-liver transplantations and compare outcomes to living donor and whole organs for adults and children.

SUMMARY BACKGROUND DATA

Split-liver transplantation is a surgical technique that creates 2 allografts from a single cadaver donor. We have applied split-liver transplantation to all indications and categories of medical urgency for initial as well as retransplantation to expand the current donor pool and decrease reliance upon living donation.

METHODS

A retrospective analysis was conducted of 100 consecutive in situ split-liver transplantations yielding a left lateral segment and right trisegment graft that were performed at the University of California Los Angeles between 9/91 and 02/03. These 100 transplantations generated 190 allografts for transplantation into 105 children and 60 adults, with the sharing of 25 allografts among transplant centers across the United States. Outcomes and incidence of complications were compared with living donor and whole organ recipients receiving liver transplantation during the same time period with independent predictors of split-liver graft and recipient survival identified by multivariate analysis.

RESULTS

The incidence of biliary and vascular complications observed in recipients of left lateral segment grafts created by split-liver transplantation was not statistically different from recipients of left lateral segment grafts created from living donation or children receiving whole-organ grafts from pediatric donors. Kaplan-Meier survival estimations of left lateral segment graft and recipient survival also demonstrated no statistical difference among split-liver, living donor, and whole-organ recipients. Right trisegment grafts from split-liver transplantation demonstrated a 10% incidence of biliary and 7% incidence of vascular complications. Long-term graft function was excellent with patient and graft survival equal to 1086 recipients of cadaver whole-organ grafts from donors ages 10-40 years who underwent transplant operations during the same time period. Predictors of split-liver transplantation graft and recipient survival included United Network for Organ Sharing status at transplantation, indication, occurrence of a complication, donor creatinine, and donor length of hospitalization.

CONCLUSIONS

Split-liver transplantation is an effective mechanism for immediate expansion of the cadaver donor pool that can reduce dependence upon living donation in adults and children.

Split-liver transplantation: a review

Split-liver transplantation (SLT), a procedure where one cadaver liver is divided to provide for two recipients, offers immediate expansion of the existing cadaver donor pool. To date, the principal beneficiaries of SLT have been adult/pediatric recipient pairs with excellent outcomes reported; however, the current scarcity of cadaver organs has renewed interest in expanding these techniques to include two adult recipients from one adult cadaver donor. Significant obstacles to the widespread application of SLT exist and must be resolved by the transplant community before greater utilization can be realized. This manuscript reviews the historic background, surgical techniques, current results, and obstacles impeding further application of SLT.

Extended criteria for organ acceptance. Strategies for achieving organ safety and for increasing organ pool

The terms extended donor or expanded donor mean changes in donor acceptability criteria. In almost all cases, the negative connotations of these terms cannot be justified. Factors considered to affect donor or organ acceptability have changed with time, after showing that they did not negatively affect graft or patient survival per se or when the adequate measures had been adopted. There is no age limit to be an organ donor. Kidney and liver transplantation from donors older than 65 years can have excellent graft and patient actuarial survival and graft function. Using these donors can be from an epidemiological point of view the most important factor to esablish the final number of cadaveric liver and kidney transplantations. Organs with broad structural parenchyma lesion with preserved functional reserve and organs with reversible functional impairment can be safely transplanted. Bacterial and fungal donor infection with the adequate antibiotic treatment of donor and/or recipient prevents infection in the latter. The organs, including the liver, from donors with infection by the hepatitis B and C viruses can be safely transplanted to recipients with infection by the same viruses, respectively. Poisoned donors and non-heart-beating donors, grafts from transplant recipients, reuse of grafts, domino transplant and splitting of one liver for two recipients can be an important and safe source of organs for transplantation.