Reducing the shortage of donor livers: what would It take to reliably split livers for transplantation into two adult recipients?

Split liver transplantation: Current developments

In 1988, Rudolf Pichlmayr pioneered split liver transplantation (SLT), enabling the transplantation of one donor liver into two recipients - one pediatric and one adult patient. In the same year, Henri Bismuth and colleagues performed the first full right/full left split procedure with two adult recipients. Both splitting techniques were rapidly adopted within the transplant community. However, a SLT is technically demanding, may cause increased perioperative complications, and may potentially transform an excellent deceased donor organ into two marginal quality grafts. Thus, crucial evaluation of donor organs suitable for splitting and careful screening of potential SLT recipients is warranted. Furthermore, the logistic background of the splitting procedure as well as the organ allocation policy must be adapted to further increase the number and the safety of SLT. Under defined circumstances, in selected patients and at experienced transplant centers, SLT outcomes can be similar to those obtained in full organ LT. Thus, SLT is an important tool to reduce the donor organ shortage and waitlist mortality, especially for pediatric patients and small adults. The present review gives an overview of technical aspects, current developments, and clinical outcomes of SLT.

Improving graft survival by understanding the mechanism of segment 4 complications after split liver transplantation

BACKGROUND

This study was designed to assess the actual mechanism of segment 4 (S4)-related complications after split liver transplantation (SLT) and their impact on graft and overall survival with reference to those of left lateral sectionectomy for pediatric living donor liver transplantation (LLSLD).

METHODS

Clinical data from 53 SLT recipients and 62 LLSLD patients were assessed to determine the mechanism of S4-related complications. The postoperative parameters of SLT and their impact on graft and overall survival were also evaluated.

RESULTS

Although two biliary leakages were noted (3.2%), no necrosis of S4 developed after LLSLD. S4-related complications were seen in 15 (28.3%) patients after SLT. Radiological volumetry of S4 and the ischemic area after SLT showed no significant difference between those with and without S4-related complications. There were no significant differences between the patients with and without S4-related complications regarding both overall and graft survival rates. Significant better overall and graft survival rates were observed in patients treated during the later period.

CONCLUSIONS

S4-related complications after SLT are totally independent of the S4 volume, and biliary leakage is inherently an actual mechanism. Adequate intervention with early identification leads to better graft and overall survival, which validates SLT as a treatment option.

Full-right-full-left split liver transplantation: the retrospective analysis of an early multicenter experience including graft sharing

Full-right-full-left split liver transplantation divides a donor liver into two grafts to be transplanted in adult-size patients. Major technical and organizational difficulties have limited its application to few single center series. We retrospectively analyzed the long-term results of the first multicenter series of this procedure with graft sharing. Between November 1998 and January 2005, 43 transplants were performed by five centers from 23 full-right-full-left in situ split liver procedures; 65% of the grafts were shared. A total of 31 (72%) patients had complications above grade II; 3 (6.9%) were retransplanted. Hospital mortality was 23% with sepsis as the main cause. Six patients died in the long term, two of them for a road accident. A total of 27 patients are alive after a median follow-up of 3200 days (2035-4256). Actuarial survival at 1 and 10 years were 72.1%, 62.6% and 65.1%, 57.9%, respectively for patients and grafts. These figures are similar to those reported for adult living donor liver transplantation by the European Registry over a similar period. Multicenter collaboration in sharing of these grafts is feasible and can help facing the organizational limits, thus increasing diffusion of full-right-full-left split liver transplantation.

Sirolimus attenuates reduced-size liver ischemia-reperfusion injury but impairs liver regeneration in rats

BACKGROUND

Evidence has suggested that immunosuppressive drugs impact ischemia-reperfusion injury.

AIMS

The purpose of the present study was to evaluate the effect of sirolimus on hepatic injury and regeneration in a rat reduced-size liver ischemia-reperfusion model.

METHODS

Using a newly developed rat reduced-size liver ischemia-reperfusion injury model, the effects of sirolimus were evaluated by assessing liver cell apoptosis and aspartate aminotransferase, myeloperoxidase, and malondialdehyde levels. In addition, liver regeneration after sirolimus treatment was evaluated by measuring liver weight resumption and by the histological examination of bromodeoxyuridine and proliferating cell nuclear antigen expression.

RESULTS

Sirolimus significantly decreased liver cell apoptosis as well as tissue myeloperoxidase and malondialdehyde levels, but impaired postischemic liver regeneration. Ischemia-reperfusion-induced elevation of aspartate aminotransferase serum levels was significantly decreased by sirolimus.

CONCLUSIONS

Despite an impairment of postischemic liver proliferation, sirolimus demonstrated beneficial amelioration of ischemia-reperfusion-induced liver injury in a reduced-size liver model in rats.

Sinusoidal perfusion in the veno-occlusive region of living liver donors evaluated by indocyanine green and near-infrared spectroscopy

Split liver transplantation and living donor liver transplantation (LDLT) commonly use a right liver graft without the middle hepatic vein (MHV). Although tributaries of the MHV are not reconstructed in the majority of cases, the alterations of the microcirculation and its regional functions remain unknown. We addressed these issues by assessing liver tissue indocyanine green (ICG) uptake with near-infrared spectroscopy (NIRS) in 21 donors. After graft procurement, visual inspection (before and after hepatic arterial clamping) and Doppler examination of the veno-occlusive region were performed. Bolus ICG (100 microg/kg) was then administered intravenously. Blood ICG at the finger tip was measured with pulse dye densitometry, whereas the liver ICG concentrations in the veno-occlusive and non-veno-occlusive regions were simultaneously measured for 15 minutes by NIRS. We estimated the hepatic ICG uptake rate constants in the veno-occlusive region (Ku-oc) and non-veno-occlusive region (Ku-non). Changes in sinusoidal perfusion in the veno-occlusive region were expressed by the ratio of Ku-oc to Ku-non (Roc/non). The median value of Roc/non was 0.47, although it ranged from 0.13 to 0.94. Roc/non was related to the extent of liver surface discoloration before and after hepatic arterial clamping (P = 0.03 and 0.01, respectively). In conclusion, sinusoidal perfusion was impaired in the veno-occlusive regions of living donor livers, but the magnitude of the effect varied greatly. Measurement of hepatic ICG uptake by NIRS could become a valuable tool for assessing the indication for venous reconstruction in LDLT and/or split donor liver transplantation.

Role of reactive metabolites of oxygen and nitrogen in partial liver transplantation: lessons learned from reduced-size liver ischaemia and reperfusion injury

1. Hepatic resection with concomitant periods of ischaemia and reperfusion (I/R) is required to perform reduced-size liver (RSL) transplantation procedures, such as living donor or split liver transplantation. Although a great deal of progress has been made using these types of surgical procedures, a significant number of patients develop tissue injury from these procedures, ultimately resulting in graft failure. 2. Because of this, there is a real need to understand the different mechanisms responsible for the tissue injury induced by I/R of RSL transplantation (RSL + I/R), with the ultimate goal to develop new and improved therapeutic agents that may limit the tissue damage incurred during RSL transplantation. 3. The present paper reviews the recent studies that have been performed examining the role of reactive metabolites of oxygen and nitrogen in a mouse model of RSL + I/R. In addition, we present data demonstrating how the pathophysiological mechanisms identified in this model compare with those observed in a model of RSL transplantation in rats.

Long-term outcome of split liver transplantation using right extended grafts in adulthood: A matched pair analysis

OBJECTIVE

Shortage of suitable organs led to the development of alternative techniques in liver transplantation. Split liver transplantation (SLT) is well established in pediatric patients. SLT is not completely accepted in adult recipients due to potential increased risk of complications. Despite satisfying results of short-term outcome, there is a leak on information of the long-term outcome. Therefore, we compared the outcome after transplantation of the right extended liver lobe with whole liver transplantation (WLT) using a matched pair's analysis.

PATIENTS AND METHODS

From the period of January 1993 to February 2005, 70 SLT recipients were matched with 70 WLT recipients of whole livers. Matching criteria were: 1) indication for transplantation, 2) United Network for Organ Sharing (UNOS) status, 3) recipient age, 4) donor age, 5) cold ischemic time, and 6) year of transplantation. The outcome was analyzed retrospectively.

RESULTS

Mean follow-up was 36 months. The 2- and 5-year patient survival rates after SLT and WLT were 86.3% and 82.6%, and 78.4% and 75.6%, respectively (log rank, P = 0.2127). Two- and 5-year graft survival rates were 77.3% and 77.3% after SLT and 71.9% and 65.8% after WLT, respectively (log rank, P = 0.3822). The total biliary complication rate was 11.4% in the SLT group versus 10.0% in the WLT group in the short-term course, while it was 8.5% after SLT and 10.0% after WLT in the long-term course. We did not observe significant differences between the groups in term of short- and long-term morbidity.

CONCLUSION

Transplantation of the right extended lobe deriving from left lateral splitting of deceased donor livers is followed by the same long-term patient and graft survival, which is known from WLT. There were no differences in the complication rates even in long-term outcome implementing that SLT does not put the adult recipient to an increased early and late risk. Transplantation of the extended right liver lobe provides a safe and efficient procedure in adult patients to expand the number of available grafts.

Divergent roles of superoxide and nitric oxide in reduced-size liver ischemia and reperfusion injury: Implications for partial liver transplantation

Hepatic resection with concomitant periods of ischemia and reperfusion (I/R) are required to perform partial liver transplantation procedures such as split liver or living donor transplantation. Although great progress has been made using these types of surgeries, there remains substantial risk to both donors and recipients, with a significant number of patients developing liver injury and failure during the course these operations. Therefore, there is need to investigate the different mechanisms responsible for the tissue injury induced by ischemia and reperfusion of a reduced-size liver (RSL+I/R) with the ultimate objective of developing new therapeutic agents that may limit hepatocellular damage induced during partial liver transplantation. This review summarizes recent studies that have been performed in a mouse model of RSL+I/R. In addition, we present data demonstrating how the pathophysiological mechanisms identified in this model compare to those observed in a rat model of RSL transplantation.

Direct bile duct visualization during the preparation of split livers

The split-liver technique is an important means to alleviating donor shortage. Its development is, at least in part, hindered by the risk of biliary complications, particularly when splitting is performed ex situ. We present a simple technique aimed at improving the identification of the biliary anatomy at the hilar level and the safety of the procedure.

Role of NADPH oxidase-derived superoxide in reduced size liver ischemia and reperfusion injury

Hepatic resection with concomitant periods of ischemia and reperfusion (I/R) is required to perform reduced size liver transplantation such as split liver or liver donor transplantation. Although great progress has been made using these types of surgeries, there remains substantial risk to both donors and recipients, with a significant number of patients developing liver injury and failure. The objective of this study was to assess the roles of superoxide (O(2)(-)) and tumor necrosis factor-alpha (TNF-alpha) in the pathophysiology of a mouse model of reduced size liver combined with ischemia and reperfusion (RSL+I/R). We found that all male mice subjected to RSL+I/R died within 3-5 days following surgery. Mortality was always preceded by dramatic increases in liver injury and TNF-alpha expression in the absence of neutrophil infiltration. Using a long-lived, polycationic form of human manganese superoxide dismutase (pcMnSOD), NADPH oxidase-deficient mice (gp91(-/-)) or a monoclonal antibody directed against mouse TNF-alpha, we demonstrated that hepatocellular injury (and mortality) were significantly attenuated. In addition, we found that pcMnSOD administration or NADPH deficiency reduced expression of TNF-alpha. Taken together, our data suggest that NADPH oxidase-derived O(2)(-) plays an important role in the pathophysiology of RSL+I/R-induced liver injury via its ability to enhance expression of TNF-alpha. We propose that therapies directed toward scavenging of O(2)(-), inhibiting NADPH oxidase, and/or immuno-neutralizing TNF-alpha may prove useful in limiting the liver injury induced by surgical procedures that require resection and I/R such as split liver or living donor liver transplantation.

Estrogen receptor-alpha, sexual dimorphism and reduced-size liver ischemia and reperfusion injury in mice

Estrogen (E(2)) exerts its effect on target organs principally by interacting with specific estrogen receptors (ER) such as ER-alpha or ER-beta. The role that these E(2) receptors play in mediating the protective effects observed in RSL+I/R induced injury remains to be defined. To study the role of ER-alpha, we anesthetized female and male wild type (wt; C57Bl/6) and ER-alpha-deficient (alphaERKO) mice and subjected them to 70% liver ischemia for 45 min followed by resection of the remaining 30% nonischemic lobes and reperfusion of the ischemic tissue. For some experiments, wt and alphaERKO male mice were injected with E(2). Survival was monitored on a daily basis while liver injury was assessed by quantifying serum alanine aminotransferase (ALT) levels and histopathology. Hepatic eNOS mRNA levels were evaluated using semi-quantitative RT-PCR. Our data showed that untreated females or males treated with E(2) survived RSL+I/R surgery indefinitely whereas all male mice given vehicle died within 3-5 days following surgery. This protective effect was diminished in alphaERKO female mice such that only 40% of alphaERKO females survived 7 d following RSL+I/R. Furthermore, liver injury was significantly higher in alphaERKO females compared with their wt counterparts and similar to those seen in wild type males and alphaERKO males. The protective effect observed in wild type females or E(2) treated males correlated well with increases in hepatic eNOS message whereas both male and female alphaERKO mice exhibited significantly lower levels of eNOS mRNA. We conclude that this protection may in part be due to the E(2)/ER-alpha-mediated activation of eNOS.

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Sexual dimorphism in reduced-size liver ischemia and reperfusion injury in mice: role of endothelial cell nitric oxide synthase

We have recently reported that female mice are protected to a much greater extent from the injurious effects of reduced-size liver ischemia and reperfusion (RSL+I/R) than are males by an estrogen-dependent mechanism. The objective of this study was to examine the possibility that the protective effect observed in female mice depends on the up-regulation and/or activation of endothelial cell NO synthase (eNOS). Anesthetized female and male wild-type or eNOS-deficient C57BL/6 mice were subjected to 70% liver ischemia for 45 min followed by resection of the remaining 30% nonischemic lobes and reperfusion of ischemic tissue. Survival was monitored daily, whereas liver injury was quantified by using serum alanine aminotransferase determinations and histopathology. Hepatic eNOS mRNA, protein, and enzymatic activity were determined in male and female mice subjected to RSL+I/R. We found that liver injury was reduced and survival increased in female mice compared with males. This protective effect correlated with significant increases in hepatic eNOS message levels and enzyme activity but not protein expression compared with males subjected to the surgery. Furthermore, N(omega)-nitro-L-arginine methyl ester-treated or eNOS-deficient female mice responded to RSL+I/R with dramatic increases in liver injury and 100% mortality within 2 days of surgery. Finally, we found that pravastatin pretreatment significantly attenuated hepatocellular injury and increased survival of male mice, which was associated with enhanced expression of eNOS message. We conclude that the protective effect afforded female mice is due to the activation of hepatic eNOS activity and enhanced NO production.

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.

Surgical anatomy of segmental liver transplantation

BACKGROUND

The emergence of split and living donor liver transplantation has necessitated re-evaluation of liver anatomy in greater depth and from a different perspective than before. Early attempts at split liver transplantation were met with significant numbers of vascular and biliary complications. Technical innovations in this field have evolved largely by recognizing anatomical anomalies and variations at operation, and devising novel ways of dealing with them. This has led to increasing acceptance of these procedures and decreased morbidity and mortality rates, similar to those observed with whole liver transplantation.

METHODS AND RESULTS

The following review is based on clinical experience of more than 180 split and living related liver transplantations in adults and children, performed over a 7-year period from 1994 to 2001.

CONCLUSION

A comprehensive understanding and application of surgical anatomy of the liver is essential to improve and maintain the excellent results of segmental liver transplantation.

Impaired volume regeneration of split livers with partial venous disruption: a latent problem in partial liver transplantation

BACKGROUND

In living-donor and split-liver transplantations using a hemi-liver graft, it is practically impossible to maintain complete venous drainage in both the right and left livers, because the middle hepatic vein can be preserved only on the unilateral side. However, it is not clear whether partial venous disturbances affect postoperative liver volume regeneration.

METHODS

Living donors who underwent left-sided hepatectomy preserving the middle hepatic vein (group A, n=40) or left hepatectomy with middle hepatic vein resection (group B, n=37) were reviewed. Volume regeneration of the remnant right paramedian (segments V + VIII) and lateral (segments VI + VII) sectors and overall liver volume was assessed at 3 postoperative months by computed tomography.

RESULTS

In group A, both sectors showed a proportional increase by 21.7% (P=0.991), whereas in group B the rate of increase of the right paramedian sector was less than that of the right lateral sector (13.3% vs. 36.5%, P<0.001). Comparisons of rate of increase for each sector between the groups indicated that interruption of the middle hepatic venous drainage impaired enlargement of the right paramedian sector and induced a compensatory hypertrophy of the right lateral sector. Overall liver mass restoration rate in group B was inferior to that in group A (78.9% vs. 85.0%, P=0.001).

CONCLUSIONS

Split livers with partial outflow disturbances are associated with latent disadvantages in postoperative liver volume regeneration even if venous congestion is not evident. These results suggest a problem of regenerative capacity of right liver grafts.

In situ splitting of the cadaveric liver for two adult recipients

BACKGROUND

Split-liver transplantation offers a unique opportunity to expand the existing donor pool. However, it has previously been stated that due to inadequate liver volume the advantages of split-liver transplantation would be lost when attempting to split the liver for two adult recipients. In this study, we sought to determine the safety, efficacy, and applicability of split-liver transplantation in select adult liver transplant recipients.

METHODS

Liver allografts for eight adult recipients were procured by in situ splitting of four adult cadaveric livers. The donor ages were 17, 19, 22, and 25 years and weights were 72, 77, 78, and 87 kg, respectively. In situ splitting resulted in three right trisegmental grafts, one right lobe graft, one left lobe graft, and three left lateral segmental grafts. The median recipient age was 49 years (range 38-61 years), whereas the median recipient weight was 84 kg (range 78-98 kg) for the right-sided grafts and 52 kg (range 51-53 kg) for recipients of the left-sided grafts. The median graft-to-recipient body weight ratio for right trisegmental, right lobe, left lobe, and left lateral segmental grafts was 1.31%, 1.26%, 1.35%, and 0.70%, respectively.

RESULTS

Overall patient and graft survival in this series is 100%. All prothrombin times were normalized within 4 days of transplantation. No evidence of ascites or prolonged hyperbilirubinemia was encountered in any right- or left-sided graft recipient. The incidence of hepatic artery, portal vein, and hepatic vein thrombosis is 0%, 0%, and 0%, respectively. Hepatic arterial anastomotic bleeding and a cut surface bile leak each occurred in one patient. Median United Network for Organ Sharing (UNOS) waiting time was 242 days (range 4-454 days) for the patients to which the donor liver was allocated. In contrast, the median waiting time for the four patients receiving the extra split-liver graft was reduced significantly to 37 days (range 21-101 days) (P<0.02).

CONCLUSIONS

This study demonstrates that split-liver transplantation can expand the cadaveric donor liver pool available for select adult liver transplant recipients. When both the donor organ and the transplant recipient are chosen carefully, split-liver transplantation can be safely performed without a delay in allograft function, increase in technical complications, or compromise in graft or patient survival.

Selected contribution: Effects of gender on reduced-size liver ischemia and reperfusion injury

Hepatic resection with concomitant periods of ischemia and reperfusion (I/R) is a common occurrence in resectional surgery as well as reduced-size liver transplantation (e.g., split liver or living donor transplantation). However, the I/R induced by these types of surgical manipulations may impair liver regeneration, ultimately leading to liver failure. The objectives of the study were to develop a murine model of reduced-size liver I/R and assess the role of gender in this model of hepatocellular injury. We found that 100% of female mice survived the surgery indefinitely, whereas all male mice had greater initial liver injury and died within 5 days after surgery. The protective effect observed in females appeared to be due to ovarian 17beta-estradiol, as ovariectomy of females or administration of a selective estrogen antagonist to female mice resulted in enhanced liver injury and greater mortality following reduced-size liver I/R. Conversely, 17beta-estradiol-treated male mice exhibited less hepatocellular damage and survived indefinitely. Taken together, these data demonstrate an estrogen-mediated protective pathway(s) that limits or attenuates hepatocellular injury induced by reduced-size liver I/R.

Split liver transplantation for two adult recipients: an initial experience

The shortage of cadaver donor livers has been most severe for adult patients. Split liver transplantation is one method to expand the donor pool, but to have a significant impact on the waiting list, it needs to be applied for 2 adult recipients. We split livers from 6 cadaver donors, and transplanted 12 adult recipients. All splits were performed in situ with transection through the midplane of the liver, resulting in a right lobe and a left lobe graft. Mean donor age was 19.7 years; mean donor weight was 79.1 kg. Mean recipient age was 41.5 years. Mean weight of right lobe recipients was 89 kg; left lobe recipients, 60 kg. All donors were hemodynamically stable and had normal liver function tests. Mean operative time for the procurement was 7.4 h. Average blood loss during the transection of the liver was 490 mL. Mean GW/ RW ratio for all recipients was 0.87%; right lobe recipients, 0.86%; and left lobe recipients, 0.88%. With mean follow-up of 9.3 months, patient and graft survival rates were both 83.3%. There were 2 deaths: 1 after hepatic artery thrombosis (HAT) and subsequent multiorgan failure; the other after HAT, a liver retransplant, and subsequent gram-negative sepsis. The remaining 10 recipients are doing well. We observed no cases of primary nonfunction. Other complications included bile leak and/or stenosis (n = 3), bleeding from the Roux loop (n = 1), bleeding after percutaneous biopsy (n = 1), and incisional hernia (n = 1). In conclusion, split liver transplantation, using 1 cadaver liver for 2 adult recipients, can be performed successfully. Crucial to success is proper donor and recipient selection.

Right-lobe living donor liver transplantation

1. Living donor liver transplantation (LDLT) is currently performed at about 30 centers in the United States. 2. Careful and critical evaluation of donor and recipient is required for optimal outcome. 3. Right lobe donation is preferred over left lobe donation in adult LDLT. 4. There has been 1 donor death (<0.3%) in the US experiences. Donor biliary complications occur in approximately 4% of the cases. 5. Recipient survival after adult LDLT in the United States is approximately 88%. Hepatic artery thrombosis occurs in 3% and biliary complications in 18%.

Split-cava technique: liver splitting for two adult recipients

Split-liver transplantation for 2 adult recipients is a challenging procedure because of the need to split through the midplane of the donor liver. In applied techniques, usually the middle hepatic vein is retained with the left split and the vena cava retained with the right split graft, particularly to avoid serious venous congestion of the right graft after reperfusion. The indispensable division of the caudate lobe veins lead to uncertain viability of liver segment I, and resection might be necessary. To provide optimal venous drainage of both hemiliver grafts, we developed the split-cava technique. This article describes our new technique of liver splitting, which has been successfully used in 2 in situ harvesting procedures.

Liver transplantation. The pediatric challenge

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

International sharing of split liver grafts in Asia: initial experience

The donor shortage problem is particularly serious in Asia and has markedly limited progress in liver transplantation. The increasing demand has, in fact, made it necessary to resort to living donor liver transplantation in both pediatric and adult recipients. Nevertheless, expanding the use of split liver allografts is yet another option to increase the supply. This has a wide potential application on a regional level because most liver transplant programs are still small and may have limited resources in terms of being able to do two transplants in one sitting. The first experience of overseas sharing of split liver grafts in Asia took place in January 1999. The graft was from a 35-yr-old donor from Kaohsiung, Taiwan, who sustained irreversible brain damage in a vehicular accident and had optimal conditions for multiorgan donation. The liver was split ex vivo and the left lateral segment was given to a 3-yr-old girl with biliary atresia at the Chang Gung Memorial Hospital. The extended right lobe split graft was transported to Hong Kong and transplanted into a 51-yr-old male patient with end-stage hepatitis C cirrhosis who was then in a state of acute failure with hepatorenal syndrome. Graft function was excellent in both recipients and the patient from Taiwan was discharged without any complications. Unfortunately, the Hong Kong recipient developed a cerebrovascular accident and required a reoperation for bile leakage from the cut surface of the liver in the early postoperative period. He has made a steady recovery since then; graft function has remained good and his kidneys have recovered. Both patients are currently alive and well 11 months post-transplant. This initial experience of overseas sharing of split liver grafts in Asia demonstrates its feasibility. It has a potentially wide applicability and could lead to the establishment of a formal organ-sharing network in the region. Established competence and mutual trust among the participating liver transplant teams would be essential in perpetuating such a graft-multiplying strategy on an organized basis.