Transplantation einer Spenderleber auf zwei Empf�nger (Splitting-Transplantation) - Eine neue Methode in der Weiterentwicklung der Lebersegmenttransplantation

Split and whole liver transplantation outcomes: a comparative cohort study

A specific split liver transplantation (SLT) program has been pursued in the North Italian Transplant program (NITp) since November 1997. After 5 yr, 1,449 liver transplants were performed in 7 transplant centers, using 1,304 cadaveric donors. Whole liver transplantation (WLT) and SLT were performed in 1,126 and 323 cases, respectively. SLTs were performed in situ as 147 left lateral segments (LLS), 154 right trisegment liver (RTL) grafts, and 22 modified split livers (MSL), used for couples of adult recipients. After a median posttransplant follow-up of 22 months, SLTs achieved a 3-yr patient and graft survival not significantly different from the entire series of transplants (79.4 and 72.2% vs. 80.6 and 74.9%, respectively). Recipients receiving a WLT or a LLS showed significantly better outcomes than patients receiving RTL and MSL (P < 0.03 for patients and P < 0.04 for graft survival). At the multivariate analysis, donor age of >60 yr, RTL transplant, <50 annual transplants volume, urgent transplantation (United Network for Organ Sharing (UNOS) status I and IIA), ischemia time of >7 hours, and retransplantation were factors independently related to graft failure and to significantly worst patient survival. Right grafts procured from RTL and either split procured as MSL had a similar outcome of marginal whole livers. In conclusion, in 5 yr, the increased number of pediatric transplants due to split liver donation reduced to 3% the in-list children mortality, and a decrease in the adult patient dropout rate from 27.2 to 16.2% was observed. Such results justify a more widespread adoption of SLT protocols, organizational difficulties not being a limit for the application of such technique.

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.

The unfinished legacy of liver transplantation: emphasis on immunology

Liver transplantation radically changed the philosophy of hepatology practice, enriched multiple areas of basic science, and had pervasive ripple effects in law, public policy, ethics, and theology. Why organ engraftment was feasible remained enigmatic, however, until the discovery in 1992 of donor leukocyte microchimerism in long-surviving liver, and other kinds of organ recipients. Following this discovery, the leukocyte chimerism-associated mechanisms were elucidated that directly linked organ and bone marrow transplantation and eventually clarified the relationship of transplantation immunology to the immunology of infections, neoplasms, and autoimmune disorders. We describe here how the initially controversial paradigm shift mandated revisions of cherished dogmas. With the fresh insight, the reasons for numerous inexplicable phenomena of transplantation either became obvious or have become susceptible to discriminate experimental testing. The therapeutic implications of the "new immunology" in hepatology and in other medical disciplines, have only begun to be explored. Apart from immunology, physiologic investigations of liver transplantation have resulted in the discovery of growth factors (beginning with insulin) that are involved in the regulation of liver size, ultrastructure, function, and the capacity for regeneration. Such studies have partially explained functional and hormonal relationships of different abdominal organs, and ultimately they led to the cure or palliation by liver transplantation of more than 2 dozen hepatic-based inborn errors of metabolism. Liver transplantation should not be viewed as a purely technologic achievement, but rather as a searchlight whose beams have penetrated the murky mist of the past, and continue to potentially illuminate the future.

Living donor liver transplantation

The introduction of living donor liver transplantation (LDLT) has been one of the most remarkable steps in the field of liver transplantation (LT). First introduced for children in 1989, its adoption for adults has followed only 10 years later. As the demand for LT continues to increase, LDLT provides life-saving therapy for many patients who would otherwise die awaiting a cadaveric organ. In recent years, LDLT has been shown to be a clinically safe addition to deceased donor liver transplantation (DDLT) and has been able to significantly extend the scarce donor pool. As long as the donor shortage continues to increase, LDLT will play an important role in the future of LT.

Technical refinements and results in full-right full-left splitting of the deceased donor liver

OBJECTIVE

Splitting of the liver at the line of Cantlie of otherwise healthy people is accepted worldwide as a reasonable procedure for the donors in adult living donor liver transplantation. A similar operation is still considered as experimental if performed in the deceased donor liver. The aim of this study is to evaluate the technical evolution and the results of this variant splitting technique.

PATIENTS AND METHODS

From January 1999 to August 2004, a total of 35 transplants of hemilivers from deceased donors (segments V-VIII: n = 16 and segments (I)II-IV: n = 19) were performed in our center. Seven splits were performed in situ and 12 ex situ. Splitting of the vena cava was applied in 18 splits and splitting of the middle hepatic vein in 8. Seven adults and 12 adolescents received the left hemiliver with a mean age of 12 years (range, 3-64 years), of whom 21% were UNOS status 1. Recipients of right hemilivers were exclusively adults with a mean age of 48 years (range, 31-65 years), none of them were high urgent. The outcome of these 35 recipients of hemilivers was prospectively evaluated.

RESULTS

Mean deceased donor age was 27 years (range, 12-57 years), the donor's body weight ranged between 55 kg and 100 kg. The mean weight of the right and left hemilivers was 1135 g (range, 745-1432 g) and 602 g (range, 289-1100 g), respectively. The mean graft recipient weight ratio in left and right hemiliver group was 1.46% (range, 0.88%-3.54%) and 1.58% (range, 1.15%-1.99%), respectively. Median follow-up was 27.4 months (range, 1-68.3 months). Four patients died (actual patient survival FR group: 87.5% versus FL group: 89.5%), 3 due to septic MOF and 1 due to graft versus host disease. In each of the 2 groups, 2 recipients had to undergo retransplantation, which resulted in an actual right and left hemiliver survival rate of 75% and 84%, respectively. The causes for retransplantation were primary nonfunction in 2 left hemilivers, chronic graft dysfunction in 1 right hemiliver, and recurrence of the primary disease in 1 recipient of a right hemiliver. Primary poor function was observed in 1 recipient of a right hemiliver. Early and late biliary complications occurred in both right and left hemiliver groups at the rate of 37.5% (n = 6) and 21% (n = 4), respectively. Arterial, portal, and venous complications were not observed in either group.

CONCLUSION

The technical development of splitting along Cantlie's line is almost complete with the last challenge being the reduction of biliary complications. The key to success is the choice of adequate deceased donors and recipients. Full-right full-left splitting is safely possible and should be considered as a reasonable instrument to alleviate mortality on the adult waiting list and to reduce the need for adult and adolescent living donation.

Adult live donor liver transplantation

The increasing awareness of liver diseases and their early detection have led to an increase in the number of transplant waiting list candidates over the past decade. This need has not been matched by the actual number of orthotopic liver transplantations performed. Live donor liver transplantation (LDLT) is an innovative surgical technique intended to expand the available organ donor pool. Although LDLT offers definite advantages to the recipient, it offers none to the donor except for the possibility of psychological well-being. Clinical research studies aimed at the prospective collection of data for donors and recipients need to be conducted.

Free radical-dependent dysfunction of small-for-size rat liver grafts: prevention by plant polyphenols

BACKGROUND & AIMS

The mechanisms by which small-for-size liver grafts decrease survival remain unclear. This study investigated the role of free radicals in injury to small-for-size grafts.

METHODS

Rat liver explants were reduced in size ex vivo and transplanted into recipients of the same or greater body weight, resulting in a graft weight and standard liver weight of approximately 50% and 25%, respectively. A polyphenol extract from Camellia sinenesis (20 microg/mL) or an equivalent concentration of epicatechin was added to the storage solution and the lactated Ringer poststorage rinse solution.

RESULTS

Serum alanine aminotransferase release increased from approximately 60 U/L before implantation to 750, 1410, and 2520 U/L after full-size, half-size, and quarter-size transplantation, respectively. Total bilirubin increased slightly after transplantation of full-size and half-size grafts but increased 104-fold in quarter-size grafts. In quarter-size grafts, histological changes included necrosis, leukocyte infiltration, and eosinophilic inclusion body formation. Polyphenol treatment ameliorated these effects by > or =67%. Survival was 30% after transplantation of small-for-size grafts. After polyphenol treatment, survival increased to 70%. Free radicals in bile assessed by spin trapping and 4-hydroxynonenal adducts measured by immunohistochemistry were also greater in reduced-size grafts, an effect ameliorated by polyphenols. Epicatechin, a major polyphenol from Camellia sinenesis, also improved graft function and decreased enzyme release, histopathologic changes, and free radical formation.

CONCLUSIONS

Increased formation of free radicals occurs after transplantation of reduced-size livers, which contributes to graft dysfunction and failure. Plant polyphenols decrease liver graft injury and increase survival of small-for-size liver grafts, most likely by scavenging free radicals.

Adult liver transplant candidate attitudes toward graft sharing are not obstacles to split liver transplantation

Split liver transplantation (SLT) benefits society by increasing the total number of transplants that can be performed, but it is yet unknown if a decreased post-transplant survival (in comparison to whole liver transplantation) would make participation in SLT less appealing to adult liver transplant candidates. A 20-item questionnaire was administered to 50 adult candidates to assess attitudes toward SLT and organ sharing. The overall attitudes of 60% of participants were classified as utilitarian (maximizing benefit to greatest number of candidates), while 26% were classified as self-preserving (maximizing individual benefit) and 14% were undecided. Ninety percent of participants would be willing to share even if expected survival was less than that of whole liver transplantation, and 69% felt that pediatric candidates should have priority over adult candidates. In conclusion, attitudes toward graft sharing and the possibility of compromised survival benefit are not barriers to SLT for most adult liver transplant candidates.

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.

Long-Term Results of In Situ Split-Liver Transplantation

BACKGROUND

Split-liver transplantation (SLT) offers immediate expansion of the cadaver donor pool. The principal beneficiaries have been adult and pediatric recipients with excellent outcomes. This study analyzed a single-center experience of adult to adult in situ SLT in adult recipients.

PATIENTS AND METHODS

Fourteen consecutive adult-to-adult in situ SLT have been performed at our institution since 1998. The extended right lobe comprising segment 1 was transplanted in to adult patients, the left lateral segment, for pediatric transplants.

RESULTS

Donors of SLT were significantly younger (P = .03) than those of whole liver transplants. Survival rates of patients receiving a split liver were 83%, 73%, and 73% at 1, 3, and 5 years after the transplant respectively and grafts of 73%, 73%, and 73% for SLT and 76%, 70%, and 66% for whole liver transplants (P = .44). The rate of biliary complication after SLT was 21%, which was comparable to that after whole organ transplantation (17%). The incidence of hepatic artery thrombosis and primary nonfunction was not significantly different between split liver and whole organ transplantation performed during the same time period (7% versus 4.6% P = .67 and 7% versus 2.6% P = .32, respectively).

CONCLUSION

This limited single-center experience confirmed that both early and long-term results of SLT are comparable to those of traditional whole liver organ transplantation.

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.

Split-liver transplantation using the left lateral segment: a collaborative sharing experience between two distant centers

Split-liver transplantation (SLT) increases the pool of organs for pediatric orthotopic liver transplantation (pOLT). With increased collaboration and organ sharing, transplant centers can fully maximize the use of all split donor allografts. Herein, we report the collaborative results between two distant centers involved in a sharing alliance. The current study consists of a retrospective review of 56 pediatric LLS transplants performed at two collaborating centers between 9/1997 and 10/2003. Fifty-three patients (41% Status 1) were transplanted using 56 left lateral segment (LLS) grafts. Sixteen percent of LLS grafts were shared between the two institutions. Overall patient survival at both 1 and 3 years was 90% and 90%, respectively. Overall graft survival at both 1 and 3 years was 82% and 82%, respectively. Shared patient and graft survival was 89% and 89%, respectively. There was an 11% biliary complication and 18% vascular complication rate. Five patients required retransplantation. In conclusion, SLT increases the number of available allografts for pOLT. While SLT is technically demanding, with a significant learning curve, patient and graft survival rates compare favorably with United Network Organ Sharing (UNOS) averages. Sharing of grafts between centers is a safe and effective way to maximize organ usage and should be actively pursued through collaborative networks.

The Main Hepatic Anatomic Variations for the Purpose of Split-Liver Transplantation

BACKGROUND/AIMS

Variant hepatic anatomy must be recognized and appropriately managed during split-liver transplantation to ensure complete vascular and biliary supply to both grafts. The aim of this study was to demonstrate the importance of an assessment of the hepatic anatomical structures for the purpose of split-liver transplantation.

MATERIAL AND METHODS

Human cadaveric livers (n = 60) were obtained during routine autopsies. The cadavers and the livers had to comply with the following requirements: (1) minimum age 18 years, (2) no liver pathology expected from medical history, and (3) no liver pathology noted at autopsy. Resections were carried out en bloc with liver, celiac trunk, left gastric artery, lesser omentum, superior mesenteric artery, and head of the pancreas. The main anatomical structures of the liver as hepatic artery, portal vein, biliary tree, and hepatic veins were dissected and correlated hepatic segments for the application of liver splitting.

RESULTS

The right the median, and the left hepatic veins were unique, with in 59 (98.3%), 53 (88.3%) and 46 (76.3%) cases, respectively. The portal vein trunk divided into right and left branches in 59 (98.3%) cases. A median branch appeared in 9 (15.2%) cases and no bifurcation of the portal vein occurred in 1 (1.6%) case. The right and left hepatic ducts were multiple in 47 (78.3%) and 57 (95%) cases, respectively, however, the median, hepatic duct was unique in 16 (26.6%) cases. Examining the intrahepatic distribution of the right hepatic duct, we found 4 branches in 28 (59%) cases (segments V, VI, VII, and VIII) 2 branches in 11 (23%) cases, (segments V and VI) and 2 branches in 8 (17%) cases (segments VII and VIII). Fifty-seven cadavers had multiple left hepatic ducts. The intrahepatic dissection showed that the distribution of the major branches were toward hepatic segments II and III. Three separate branches of the left hepatic duct were found in 11 (19%) cases (segments II, III, and IV). Two intrahepatic ducts coming from hepatic segments V and VI drained separately into the left intrahepatic biliary tree in 1 (2%) case. The arterial supply of the liver was by right and left hepatic artery with only 9 (15%) cases there being median hepatic artery. The right hepatic artery, coming from the superior mesenteric artery, was present in 15 (25%) cases and a left hepatic artery originating from the left gastric artery in only 2 (3.3%) cases. The left hepatic artery had 2 exceptional origins, in 1 (1.6%) case coming directly from the abdominal aorta and in the other from the superior mesenteric artery. The right and left hepatic artery was accessory, in 11 (18.3%) and 2 (3.3%) cases, respectively. The right hepatic artery was dominant in 4 (6.6%) cases. The median hepatic artery was directed to segment IV in 6 (10%) cases and to segment II and III in 3 (4.9%) cases.

CONCLUSION

The study showed that the technique of controlled liver splitting for transplantation in 2 recipients is an acceptable method to increase the number of liver allografts. The anatomical and technical details of the splitting procedure are critical for the success of this technique. Good graft function and avoidance of complications depend on each graft having an intact arterial and portal blood supply as well as biliary and venous drainage from all retained liver segments. The absence of a bifurcation of the portal vein is a rare anomaly and would certainly contraindicate a partition.

Presence of multiple bile ducts in the liver graft increases the incidence of biliary complications in pediatric liver transplantation

We studied the impact of multiple bile duct anastomosis on the development of biliary complications after liver transplantation in children. A total of 101 patients received a primary liver transplant and were divided into 2 groups: those with a single bile duct (n = 77) and those with multiple bile ducts (n = 24). Mean follow-up was 39.8 +/- 20.8 months. A total of 27 patients presented with biliary complications (26.7%), 18 patients (18.7%) presented with early complications (12 leaks and 6 strictures), and 9 patients (8.9%) had late strictures. Hepatic artery thrombosis (HAT) and multiple bile ducts were significant risk factors for the development of biliary complications, and the presence of multiple bile ducts was an independent risk factor. Patients with multiple bile ducts had a significantly greater incidence of total biliary complications compared to those with single ducts. Patients with multiple ducts had a higher incidence of leaks when compared to those in the single duct group, but the incidence of strictures, both early and late, was similar in both groups. One-year patient and graft survivals were not statistically different in the 2 groups. In conclusion, the presence of more than one bile duct in the graft is an independent risk factor for the development of biliary complications after pediatric liver transplantation.

Anesthesia for liver transplant surgery

Liver transplantation offers patients with liver disease an optimal chance for long-term survival. Current indications, preoperative assessment, patient selection, intraoperative anesthetic management and outcomes are described. The management of special situations, including retransplantation, pediatric transplantation, and fulminant hepatic failure are also reviewed. The success of liver transplantation has led to increased demand. This demand, coupled with a nonexpanding supply of deceased donor organs, has resulted in a shortage of grafts and prolonged waiting times. Novel solutions using segmental liver grafts from living donors, and the challenges associated with this approach, are discussed.

Living related liver transplantation

The introduction of cyclosporine was a major advance in liver transplantation, leading to increased numbers of liver transplant cases and, at the same time, a relative shortage of available donor organs. As one of the modalities to decrease the mortality rate on the waiting list, living related liver transplantation (LRLT) was initiated. In the LRLT program of Kyoto University, which started in June 1990, the number of cases has increased yearly as its application expanded from pediatric to adult patients. A landmark in LRLT was the introduction of right lobe grafts, which have become a standard procedure in adult-to-adult living donor liver transplantation. The basic immunosuppressive regimen consisted of tacrolimus and low-dose steroids from the beginning of our LRLT program. However, since documentation of significant improvements in clinical efficacy with Neoral compared to Sandimmun-based immunosuppression, the role of cyclosporine in LRLT is now being reevaluated.

Split liver transplantation: past, present and future

The technique of liver splitting offers an effective way of increasing the donor pool and decreasing pediatric waiting list mortality. A donor liver is divided in such a way that the left lateral liver graft can be transplanted into a small child and the right extended liver graft into an adult. This innovative technique did not harm the adult recipient pool. Because of its technical complexity and the initial poor results after split liver transplantation (SLT) this procedure has slowly gained acceptance in the Transplantation Community after its first introduction in 1988 (4). Small children with end stage liver disease suffered the most from the extreme shortage of cadaveric donor organs due to the difficulty of finding size-matched donors. The successful surgical development of SLT and a better donor and recipient selection have led to a reduction of the pediatric pretransplant mortality to nearly zero and to results comparable with those after whole organ transplantation (WLT). By splitting a donor organ into two 'full' hemi-grafts and providing a small adult ( < 60 kg) or a big child ( > 30 kg) with the full left graft and a medium-sized adult (60-80 kg) with the full right graft, a small-for-size situation for adolescents or adults can be avoided and the total number of available grafts can be increased. It is the goal to provide each recipient with its customized graft in the near future. However, splitting for two adults requires high technical skills and profound knowledge of the anatomic variations and should be performed in centers with large transplantation experience.

Paediatric liver transplantation--a review based on 20 years of personal experience

The natural history of most liver diseases requiring liver replacement in children is well known, and the potential of this therapy has been ascertained regarding life expectancy, which currently exceeds 90% in the long term. The timing of liver transplantation must be anticipated, to reduce the physical, psychological and mental impact of chronic liver diseases. Several studies show evidence that the best long-term results with regard to patient and graft survival are obtained with grafts procured from relatively young donors. Since the shortage of post-mortem liver donors will most likely worsen, further development of live, related-donor transplantation can be expected. The main progress to come will concern immunosuppression, taking advantage of the immunological privilege of the liver. Protocols are under development for induction of operational tolerance.

Estimation of standard liver volume for liver transplantation in the Korean population

The standard liver volume (LV) of a recipient is estimated in liver transplantation to determine the minimum LV necessary for the recipient. Simple linear formulas of LV estimation were developed for the Japanese and Caucasian populations. The present study examined the applicability of the reported formulas to the Korean population. Liver density (LD) was determined by analyzing 24 healthy livers. Data of liver weight (LW), body weight (BW), body height (BH), body surface area (BSA), and age were obtained from 652 postmortem examination reports (age, 42.4 +/- 16.5 years) showing normal livers. The LV of each subject was estimated by LW / LD and the relationships between LV, BW, BSA, and age were analyzed. LD was 1.04 +/- 0.07 kg/L. LV / BW decreased as age increased in the children but leveled off in the adults; the rate of increase in LV along with BSA in individuals with BSA <1.2 m(2) appeared less than the corresponding rate in individuals with BSA >/=1.2 m(2). The Japanese formula produced underestimates for the Korean population (226.9 +/- 289.4 mL), while the Caucasian formula produced random errors (-30.64 +/- 281.5 mL). A better LV estimation formula was established: LV (mL) = 21.585 x BW (kg)(0.732) x BH (cm)(0.225) (adjusted R(2) = 0.59; SE = 275.8 mL). In conclusion, this study indicates that a nonlinear or piecewise linear model is more desirable than a simple linear model for LV estimation in children and adults, because LV / BW and LV / BSA are not constant with age and BSA.

Split liver transplantation in Italy

The role of split liver transplantation has been well established. The limitation to this technique is the number of potential recipients for a left lateral segment graft. The optimal use of the donor pool is to split the liver to provide 2 grafts suitable for adults obtaining right or left lobe. We explored the potential increase in the number of liver grafts gained from systematically using the technique of splitting on national basis. The crucial factor appeared to be creation of guidelines for the use of optimal livers to optimize organ allocation while minimizing pretransplantation mortality and maximizing post-orthotopic liver transplantation outcome.

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.

Homozygous familial hypercholesterolemia: specific indication for domino liver transplantation

BACKGROUND

Domino liver transplantation is one possibility to overcome the discrepancy between the small number of liver donors and the long waiting lists. Homozygous familial hypercholesterolemia (FHC) is a genetic disorder of lipoprotein metabolism defined by the absence or small number of functional low-density lipoprotein receptors (LDL-Rs) and the ensuing high levels of serum cholesterol. We report a case of a patient with FHC whose liver was used for domino transplantation in a patient with cirrhosis and hepatocellular carcinoma.

METHODS

The patient diagnosed with FHC received the large part of a split liver. The liver of the patient with FHC was then transplanted into the patient with cirrhosis and hepatocellular carcinoma. Quantification of extrahepatic LDL-R was performed by flow cytometry on monocytes, and the gene expression of LDL-R was assayed by reverse transcriptase-polymerase chain reaction on monocyte-derived macrophages and cultured fibroblasts isolated from the patients.

RESULTS

One year after surgery, the donor's serum cholesterol (without treatment) was normal, and the recipient's serum cholesterol (with simvastatin treatment) was slightly increased. Quantification of peripheral LDL-R on monocytes isolated from the patients revealed values of 6.7% in the patient with FHC and 71% in the patient with cirrhosis and hepatocellular carcinoma. The reverse transcriptase-polymerase chain reaction assay revealed the presence of gene expression for LDL-R.

CONCLUSIONS

Domino transplantation can be efficiently used in a patient with marginal indications for transplantation using a liver from a patient with FHC. The slightly elevated serum cholesterol level in the recipient may be explained by the normal function of extrahepatic LDL-R.

Split liver transplantation

Split liver transplantation offers an attractive way to increase the number of cadaveric grafts. In the past 10 years, it has enabled clinicians to minimise paediatric waiting list mortality. Two major concepts are applied in liver splitting. The more widely accepted approach provides a left lateral and a right extended liver graft to be transplanted into one child and one adult, respectively. To date the results from this technique are comparable to whole organ techniques for both the paediatric and the adult recipient. The second principle of splitting the liver provides two 'full' hemi-grafts-the left side for a small adult or big child and the right for a medium-sized adult patient. Full right/full left splitting is an important means of expanding the adult liver graft pool; however, it is a complex variant of liver transplantation that requires a high level of technical skill and a comprehensive knowledge of possible anatomic variations. Splitting for two adults should be performed in centres with a significant annual volume of liver transplantations, experience with left lateral splitting and an active program of hepatobiliary surgery. This brief review discusses anatomical and technical aspects and summarises the experience of both approaches to split liver transplantation to date.

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.

A critical review of the major indicators of prognosis after resection of hepatic metastases from colorectal carcinoma

Hepatic resections for metastatic colorectal cancer have dramatically increased, and there is clear evidence of the effectiveness of this type of surgery. Controversy, however, persists regarding appropriate patient selection, extent and timing of liver resection, and adjuvant or alternative therapeutic options. This article reviews the authors' experience with more than 600 hepatic resections and the relevant literature is discussed. The results underscore the importance of macroscopically and histologically complete tumor clearance, a so-called "R0 resection."

Ex situ preparation of left split-liver grafts with left vascular pedicle only: is it safe? A comparative single-center study

The procurement of left-lateral-segment grafts from living donors for transplantation in children is performed by retaining only the left branches of the artery and veins. New techniques and the implementation of microsurgery in the transplant operation made this procedure a successful approach. However, controversy persists about using such an approach for division of liver grafts from cadaveric donors, and many teams prefer retaining the main arterial trunk with the left split graft, with or without the main portal vein trunk. Since 1998, in our center, when a donor-liver graft is divided we prefer retaining the main vessels with the right split graft if graft vascular anatomy is favorable. After 1998, 40 liver grafts from cadaveric donors were divided, and all divisions were performed ex situ. This experience was retrospectively reviewed to compare the outcome of left split grafts prepared for implantation with the left vasculature only (group A), or with the main arterial supply (group B). A single vascular complication occurred (one hepatic artery thrombosis in group B). Three patients died (one in group A and two in group B) and three other grafts were lost (one in group A and two in group B). One-year and 3-year graft survival rates were 94% and 86% in group A, and 83% and 83% in group B, respectively (not significantly [NS] different). We conclude that left split grafts can be safely transplanted with the left vascular supply only, provided that division is guided by careful anatomical evaluation and that vascular reconstructions are adequate.

Split liver transplantation and risk to the adult recipient: analysis using matched pairs

BACKGROUND

The technique of liver splitting is an effective way of increasing the donor pool and reducing pediatric waiting list mortality. But the procedure is still not fully accepted because of concerns that it may cause complications in adult recipients.

STUDY DESIGN

Fifty-nine adult recipients of primary extended right split liver transplantations (SLTs) were matched to recipients of whole liver transplantations (WLTs) according to the following criteria: 1) United Network for Organ Sharing (UNOS) status, 2) donor age, 3) recipient age, 4) total cold ischemic time, 5) indication for liver transplantation, 6) Child-Pugh class, and 7) year of transplantation. A WLT-recipient match was identified in 40 adult recipients of primary SLT.

RESULTS

Fifteen percent of the recipients in our study were highly urgent cases (UNOS 1), and 85% were UNOS status 3-4. The 3- and 12-month patient survival rates after SLT and WLT were 82.5% and 77.1%, and 92.5% and 87.5%, respectively (log rank p = 0.358). The 3- and 12-month graft survival rates showed no significant difference in either group (80% and 74% in SLT and 87.5% and 77.4% in WLT [log rank p = 0.887]). The rates of primary nonfunction, primary poor function, biliary and vascular complications, intra- and postoperative blood transfusion, and intensive care stay were comparable for SLT and WLT.

CONCLUSIONS

SLT, using the extended right hepatic lobe, does not notably differ from WLT with regard to initial graft function, postoperative complications, or patient and graft survival. Based on this, the liver can be considered a paired organ, and mandatory splitting of good-quality livers can be recommended.

Donor and recipient outcomes in right lobe adult living donor liver transplantation

Severe donor organ shortage has provided the impetus for adult living donor liver transplantation (ALDLT). Despite rapid implementation and expansion of the procedure, outcome analysis of ALDLT is still incomplete. This study analyzed both donor and recipient outcomes after ALDLT at a single center. ALDLT performed at UCLA between August 1999 and November 2001 were reviewed retrospectively. Twenty recipients (14 men and 6 women) with a mean age of 48.8 +/- 9.7 (29 to 66) years underwent right lobe ALDLT. By computed tomograpy (CT), graft/recipient weight ratio (GRWR) was 1.3 +/- 0.3 (1 to 2.2). Overall 1-year patient and graft survival rates were 95% and 85%, respectively. One recipient died of heart failure with normal liver function 5 months after transplantation. Three grafts (14%) were lost and all three patients underwent successful cadaveric retransplantation. Complications were classified according to the Clavien grading system with all but 3 recipients encountering at least one complication. Nine (45%) had grade 1 (minor), 10 (50%) had grade 2 (potentially life threatening without residual disease/disability), 3 (14%) had grade 4A (retransplantation) and one grade 4B (death). Right lobectomy for living donation was performed in 20 patients (12 men, 8 women). Residual left lobe volumes were 36 +/- 5.3 (23.9 to 47.9)% of total donor liver volume. No donor required intensive care unit admission and median hospital stay was 7.5 (6 to 14) days. One donor was aborted after intraoperative biopsy showed > 50% macrovesicular steatosis. No donor mortality or long-term complications were encountered. Five grade 1 minor complications, by Clavien Classification, occurred in 4 of 20 (20%) donors. ALDLT using right lobe grafts is an effective procedure to expand a severely depleted donor, but is associated with a high complication rate despite good survival outcomes. Continuous standardized reporting of ALDLT outcomes is required to allow successful and safe implementation of the procedure.

Split liver transplantation

Greater experience and improved outcomes in liver transplantation have necessarily led to longer waiting lists against a constantly limited donor pool. Split liver transplantation has been conceived as a means to increase the supply of liver grafts. The bipartition of a whole liver provides grafts for two recipients in a complex operation with equally complex manpower and logistical demands. The in situ technique of splitting offers advantages over the ex vivo technique, although after the time-dependent learning curve is overcome, they may theoretically be used interchangeably with acceptable outcomes. Aside from surgical expertise, donor characteristics and recipient pre-transplant status are risk factors for survival. This review will address the salient aspects of split liver transplantation, summarize the world experience with this procedure and describe the preliminary attempts in Asia.

History of pediatric liver transplantation. Where are we coming from? Where do we stand?

The history of pediatric liver transplantation cannot be dissociated from one man, Thomas E. Starzl, whose pioneer efforts contributed more than anyone else to what has become a routinely successful clinical procedure. During the pre-cyclosporine era, the pediatric experience was confined nearly exclusively in Denver: first attempt in 1963, first success with survival beyond one year in 1967, cumulative experience with 84 pediatric cases in the pre-cyclosporine era (1967-1979) with a 2-year patient survival rate of 30%. The stampede for the development of other liver transplant centers came with the introduction of cyclosporine in the early eighties. Besides Pittsburgh, seven centers (Brussels, Cambridge and Hanover in Europe; Boston, Dallas, UCLA, Minneapolis in USA) had performed up to 1986 at least 20 pediatric liver transplants each with a long-term (>1 year) patient survival rate ranging between 57% and 83%. At the moment, a long-term patient survival rate in excess of 90% in elective patients -including infants - is commonly obtained in experienced centers. The shortage of size matched liver donors which was responsible for a high death rate on the cadaveric waiting list stimulated the development or technical innovations based on the segmental anatomy of the liver: reduced ('cutdown') liver graft, split graft and living liver transplantation. Challenging technical aspects in the recipient have been solved in order to reduce the incidence of surgical complications like outflow obstruction, arterial and portal thrombosis, and biliary problems. The indications of liver transplantation have been refined; regarding biliary atresia, which is the most frequent indication, a consensus has developed to propose a sequential strategy with a single attempt at hepatoportoenterostomy followed, when it fails, by liver transplantation. Some contra-indications accepted in the past are not currently valid with better understanding of the pathophysiology and/or increased clinical experience; such is the case of the hepatopulmonary syndrome. A major progress in preoperative management has been achieved through a multidisciplinary approach, particularly regarding nutrition and control of portal hypertension-related bleeding and ascites. Perioperatively, liver transplantation has derived benefit from the expertise of anesthetists managing babies with serious conditions and increased experience of the transplant surgeons regarding the knowledge of all the technical modalities, good strategy, technical skills and meticulous control of bleeding. It is well-recognized that children require more immunosuppression than adults. As in adults, the first breakthrough came with the introduction of cyclosporine which more than doubled the one-year patient survival rate. The next advance during the last decade was afforded by FK 506 - Tacrolimus which allows steroid withdrawal with the first year post-transplant in most patients. Besides its efficacy in reducing the incidence of rejection and absence of cosmetic side-effects, the steroid-sparing effect of Tacrolimus is of utmost importance to preserve the growth potential of children. The use of OKT-3 both for induction and treatment of rejection has been abandoned nearly universally because its use, cumulated with other immunosuppressants, resulted in a high incidence of lymphoproliferative disorder. In contrast, anti-IL2-receptor monoclonal antibodies, will most likely gain an increasing place in induction, with the availability of chimeric or humanized preparations. The side-effects of immunosuppression can endanger both the quality of life and the life expectancy; they are a special source of concern in pediatric recipients whose survival can be expected to be more than a few decades. Children would benefit most from the development of a marker able to identify the patients who have developed graft acceptance, allowing complete wearing of immunosuppression. Also they would benefit most from research protocols of tolerance induction. Since the vast majority of liver-transplanted children will have a reasonably normal life expectancy, the focus should be switched to their long-term rehabilitation and the assessment of their quality of life when they reach adulthood.

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

The American Society of Transplant Surgeons and the American Society of Transplantation jointly sponsored a conference in Crystal City, Virginia, on March 28th and 29th, 2001, to explore mechanisms for maximizing the cadaver-organ donor pool. Participants from transplantation medicine, surgery, organ procurement organizations, the general public, and government convened to address expanding utilization of each organ type. The committee assigned to review liver organ utilization identified multiple practices that could expand the potential donor pool including non-heart beating donors, marginal grafts, efficient allocation of cadaver organs, and wider application of split-liver transplantation. This article details the data reviewed by the liver committee and their recommendations on policy development for the expanded application of split-liver transplantation.

Evaluation of hepatic venous congestion: proposed indication criteria for hepatic vein reconstruction

OBJECTIVE

To establish criteria for venous reconstruction of middle hepatic vein (MHV) tributaries of the right liver graft in adult-to-adult living donor liver transplantation (LDLT).

SUMMARY BACKGROUND DATA

In adult LDLT using the right hemiliver, the MHV is usually separated from the graft, which results in potential venous congestion in the major part of the right paramedian sector (segments 5 and 8). It is controversial whether MHV tributaries should be reconstructed.

METHODS

Thirty-nine donors for LDLT were enrolled in the study. After liver transection, temporary arterial clamping was carried out to visualize congestion in the right paramedian sector by occlusion of MHV tributaries. Intra- and postoperative (on postoperative days 3 and 7) Doppler ultrasonography was performed to check the hepatic venous and portal flow in the veno-occlusive area.

RESULTS

In 29 of 37 donors (78%), the liver surface of the veno-occlusive area was discolored with temporary arterial clamping. The discolored area was calculated to represent approximately two thirds of the right paramedian sector on computed tomography volumetry. All of the cases with discoloration exhibited absent venous flow and regurgitated portal flow in the discolored area by intraoperative Doppler ultrasonography. These ultrasonographic findings resolved by postoperative day 7 in 6 of 14 cases (43%).

CONCLUSIONS

The state of venous congestion in the right liver graft can be correctly assessed by the temporary arterial clamping method and intraoperative Doppler ultrasonography. If the venocongestive area is demonstrated to be so large that the graft volume excluding this area is thought to be insufficient for postoperative metabolic demand, venous reconstruction is recommended.