Liver transplants from living related donors

Evaluation of Living Liver Donors

As a result of the cadaveric organ shortage, the number of centers performing living donor liver transplantation has increased. Living donor liver transplantation provides immediate organ availability and avoids the risk of life-threatening complications that occur with long waiting times for cadaveric organs; however, it puts a healthy person at risk for little personal gain. A standardized approach to donor evaluation ensures safety to potential donors. Careful medical (physical examination as well as laboratory and radiological evaluation) and psychological evaluation is imperative to reduce donor complications and ensure good outcomes in recipients. A social worker and psychiatrist assess for mental competency, provide emotional support, and can serve as independent donor advocates. Informed understanding and consent are crucial aspects of the evaluation and include ensuring that the donor understands all potential complications and is free of coercion. Safety of the donor must be the highest priority.

Intraoperative care of the transplant patient

Patients undergoing abdominal organ transplantation have extensive comorbidities that can affect many organ systems including the cardiovascular system. Intraoperative anesthesia care can be very challenging and requires thorough understanding of the disease specific physiology as well as knowledge of the comorbidities and the surgical procedure. There is no approach to intraoperative anesthesia care that will work equally well for every center but standardization of protocols for each transplant center will improve patient care and safety and ultimately contributes to superior outcomes. In this article we provide background and suggestions that will help with the development of standardized protocols for intraoperative management.

Remote ischemic preconditioning promotes early liver cell proliferation in a rat model of small-for-size liver transplantation

BACKGROUND

The size of the liver donor graft is a major concern in living donor liver transplantation. Rapid regeneration is essential for the survival of these grafts. The purpose of this study was to investigate the effect of remote ischemic preconditioning (RIPC) on liver regeneration in a rat small-for-size liver transplantation model.

METHODS

We established rat models of small-for-size liver transplantation (30%) in the presence or absence (control) of remote ischemic preconditioning. We observed liver mass regeneration, serum alanine aminotransferase, hepatic pathologic alterations, flow cytometry, and Ki-67 antigen immunohistochemistry. In addition, using Western blotting and reverse-transcriptase-polymerase chain reaction, we assessed the activation of cell cycle progression as well as tumor necrosis factor-α and interleukin-6 expression.

RESULTS

Compared with the control group, serum alanine aminotransferase activity was significantly lower and histopathology changes were significantly attenuated in the RIPC group. Remote ischemic preconditioning induced a high level of interleukin-6 mRNA in small grafts, but suppressed the expression of tumor necrosis factor-α. The proliferation index, indicated by the S-phase and G2/M-phase ratio [(S+G2/M)/(G0/G1+S+G2/M)], was significantly increased in the RIPC group at 24 h (58.25% ± 0.506% versus 53.405% ± 1.25%; P = .007). Meanwhile, cell cycle progression and regeneration (Ki-67) were initiated early in liver grafts treated with RIPC.

CONCLUSIONS

These results suggest that RIPC can protect liver cells against ischemia reperfusion injury in the small grafts and enhance liver regeneration. Interleukin-6 may be a critical mediator in the stimulatory effect on liver cell regeneration, which may make RIPC valuable as a hepatoprotective modality.

The use of a reversible proteasome inhibitor in a model of Reduced-Size Orthotopic Liver transplantation in rats

Ischemia/reperfusion injury (IRI), inherent in liver transplantation (LT), is the main cause of initial deficiencies and primary non-function of liver allografts. Living-related LT was developed to alleviate the mortality resulting from the scarcity of suitable deceased grafts. The main problem in using living-related LT for adults is graft size disparity. In this study we propose for the first time that the use of a proteasome inhibitor (Bortezomib) treatment could improve liver regeneration and reduce IRI after Reduced-Size Orthotopic Liver transplantation (ROLT). Rat liver grafts were reduced by removing the left lateral lobe and the two caudate lobes and preserved in UW or IGL-1 preservation solution for 1h liver and then subjected to ROLT with or without Bortezomib treatment. Our results show that Bortezomib reduces IRI after LT and is correlated with a reduction in mitochondrial damage, oxidative stress and endoplasmic reticulum stress. Furthermore, Bortezomib also increased liver regeneration after reduced-size LT and increased the expression of well-known ischemia/reperfusion protective proteins such as nitric oxide synthase, heme oxigenase 1 (HO-1) and Heat Shock Protein 70. Our results open new possibilities for the study of alternative therapeutic strategies aimed at reducing IRI and increasing liver regeneration after LT. It is hoped that the results of our study will contribute towards improving the understanding of the molecular processes involved in IRI and liver regeneration, and therefore help to improve the outcome of this type of LT in the future.

Opposing roles of RAGE and Myd88 signaling in extensive liver resection

In extensive liver resection secondary to primary or metastatic liver tumors, or in living donor liver transplantation, strategies to quell deleterious inflammatory responses and facilitate regeneration are essential. The receptor for advanced glycation endproducts (RAGE) and myeloid differentiating factor 88 (Myd88) are implicated in the inflammatory response. To establish the contributions of RAGE vs. Myd88 signaling in extensive liver resection, we probed the effect of RAGE and/or Myd88, the latter primarily a key transducer of major toll-like receptors and also implicated in interleukin-1 (Il1) signaling, in a murine model of extensive (85%) hepatectomy. We report that, although Myd88 is thoroughly essential for survival via regulation of NF-κB and TNF-α, deletion of RAGE significantly improved survival compared to wild-type, Myd88-null, or RAGE-null/Myd88-null mice. RAGE opposes Myd88 signaling at multiple levels: by suppression of p65 levels, thereby reducing activation of NF-κB and consequent production of cyclin D1, and by suppression of Il6-mediated phosphorylation of Stat3, thereby down-regulating Pim1 and suppressing the hyperplastic response. Further, RAGE-dependent suppression of glyoxalase1, a detoxification pathway for pre-AGEs, enhances AGE levels and suppresses Il6 action. We conclude that blockade of RAGE may rescue liver remnants from the multiple signals that preclude adaptive proliferation triggered primarily by Myd88 signaling pathways.

Medicare, ethics, and reflexive longevity: governing time and treatment in an aging society

The clinical activities that constitute longevity making in the United States are perhaps the quintessential example of a dynamic modern temporality, characterized by the quest for risk reduction, the powerful progress narratives of science and medicine, and the personal responsibility of calculating the worth of more time in relation to medical options and age. This article explores how medicine materializes and problematizes time through a discussion of ethicality-in this case, the form of governance in which scientific evidence, Medicare policy and clinical knowledge and practice organize first, what becomes "thinkable" as the best medicine, and second, how that kind of understanding shapes a telos of living. Using liver disease and liver transplantation in the United States as my example, I explore the influence of Medicare coverage decisions on treatments, clinical standards, and ethical necessity. Reflexive longevity-a relentless future-thinking about life itself-is one feature of this ethicality.

Matrix metalloproteinase 2 in reduced-size liver transplantation: beyond the matrix

We studied the contribution of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) to the beneficial effects of preconditioning (PC) in reduced-size orthotopic liver transplantation (ROLT). We also examined the role of c-Jun N-terminal kinase (JNK) and whether it regulates MMP2 in these conditions. Animals were subjected to ROLT with or without PC and pharmacological modulation, and liver tissue samples were then analyzed. We found that MMP2, but notMMP9, is involved in the beneficial effects of PC in ROLT. MMP2 reduced hepatic injury and enhanced liver regeneration. Moreover, inhibition of MMP2 in PC reduced animal survival after transplantation. JNK inhibition in the PC group decreased hepatic injury and enhanced liver regeneration. Furthermore, JNK upregulated MMP2 in PC. In addition, we showed that Tissue inhibitors of matrix metalloproteinases 2 (TIMP2) was also upregulated in PC and that JNK modulation also altered its levels in ROLT and PC. Our results open up new possibilities for therapeutic treatments to reduce I/R injury and increase liver regeneration after ROLT, which are the main limitations in living-donor transplantation.

Roller Coaster Marathon: Being a Live Liver Donor

The purpose of this phenomenological study was to examine the meaning of being a live liver donor. Six people between ages 27 and 53 years participated. A qualitative, in-depth, semistructured interview format was used to explore donors' thoughts and feelings about being an organ donor. Five themes were identified: (1) no turning back—how do I live without you? (2) roller coaster marathon, (3) donor network, (4) the scar, and (5) reflections—time to think. At the center of the experience was the donor's commitment to the recipient. Once donors began the process, they were determined to see it through. The process was complex, and donors received various levels of support from family, friends, health care professionals, and others. After donation, as donors recovered and were able to resume their usual daily responsibilities, they reflected on the impact of the experience and how it changed their view of life.

Laboratory diagnosis and nonoperative management of biliary complications in living donor liver transplant patients

BACKGROUND

Biliary complications associated with living donor liver transplantation (LDLT) remain a major problem. Information regarding biochemical abnormalities helpful for the diagnosis and the nonoperative management of such complications are limited.

METHODS

Adult patients who underwent LDLT were retrospectively studied for biliary complications. Clinical findings and laboratory studies, that is, serum bilirubin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase were evaluated. Diagnostic percutaneous transhepatic cholangiogram or endoscopic retrograde cholangiogram followed by therapeutic interventions such as endoscopic sphincterotomy, stone extraction, balloon dilation, or stent placement were done as indicated. Follow-up data on clinical and biochemical outcomes were assessed.

RESULTS

Among the first 29 patients who underwent LDLT, 7 patients (24%) developed biliary complications. Nonoperative treatment was undertaken through endoscopic retrograde cholangiogram in 4 cases, percutaneous transhepatic cholangiogram in 3 cases with a successful clinical outcome in 6 cases (84%). All patients with biliary stricture had a bilirubin level >1.5 mg/dL with 100% sensitivity.

CONCLUSIONS

A number of patients developed biliary complications after LDLT. Nonoperative treatments were successful in most patients. Elevated serum bilirubin level may be helpful in the diagnosis of biliary stricture complicating LDLT.

How ischaemic preconditioning protects small liver grafts

Interleukin-1 (IL-1) and transforming growth factor-beta (TGFbeta) are key inhibitors of hepatocyte proliferation after hepatectomy. IL-1 inhibition by heat shock proteins (HSPs) has been reported in inflammatory processes. A recent study indicated the benefits of ischaemic preconditioning in reduced-size orthotopic liver transplantation (ROLT). The present study examined: (a) the effect of ischaemic preconditioning on IL-1 and TGFbeta in ROLT; (b) whether preconditioning protects small liver grafts through HSP induction; and (c) whether the potential benefits of preconditioning on HSP is related to IL-1 inhibition. Our results, obtained with an IL-1 receptor antagonist, indicated the injurious effects of IL-1 in ischaemia-reperfusion (I/R) injury and established a relationship between IL-1 and growth factors. Thus, IL-1 reduced hepatocyte growth factor (HGF) and promoted TGFbeta release, thus contributing to the impaired liver regeneration associated with ROLT. Preconditioning inhibited IL-1 through nitric oxide (NO), thereby protecting against the injurious effects of IL-1. In addition, by another pathway independent of NO, preconditioning induced HSP70 and haem-oxygenase-1 (HO-1). HO-1 protected against I/R injury and liver regeneration, whereas the benefits resulting from HSP70 were mainly related to hepatocyte proliferation. These results suggest a mechanism that explains the effectiveness of preconditioning in ROLT. They suggest, too, that other strategies, in addition to preconditioning, that modulate IL-1 and/or HSPs could be considered in clinical situations requiring liver regeneration such as small liver grafts.

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.

The current status of living donor liver transplantation

In response to the critical organ shortage, transplant professionals have utilized living donors in an attempt to decrease the mortality rate associated with waiting on the liver transplant list. Although the surgical techniques were first utilized clinically 15 years ago, application of LDLT has been somewhat limited by the steep learning curve associated with developing a program. Clinical success with LDLT in children was realized early in the experience and application of the techniques to the adult population has occurred more recently. Although transplant centers embark on LDLT with enthusiasm, the safety of the donor must always be at the forefront of the process. Potential donors must come to the decision to donate without pressure from members of the family or transplant team. He/she should also be assigned advocates who constantly promote the donor's best interest. Failure to adhere to strict donor evaluation protocols and standardized operative techniques could result in disastrous consequences.

Causes of arterial bleeding after living donor liver transplantation and the results of transcatheter arterial embolization

Objective

To analyze the causes of arterial bleeding after living donor liver transplantation (LDLT) and to evaluate the efficacy of transcatheter arterial embolization (TAE).

Materials and Methods

Forty-two sessions of conventional arteriography were performed in 32 of the 195 patients who underwent LDLT during the past 2 years. This was done in search of bleeding foci of arterial origin. TAE was performed with microcoils or gelatin sponge particles. The causes of arterial bleeding, the technical and clinical success rates of TAE and the complications were retrospectively evaluated.

Results

Forty-two bleeding foci of arterial origin were identified on 30 sessions of arteriography in 21 patients. The most common cause of bleeding was percutaneous procedures in 40% of the patients (17 of the 42 bleeding foci) followed by surgical procedures in 36% (15/42). The overall technical and clinical success rates of TAE were 21 (70%) and 20 (67%) of the 30 sessions, respectively. The overall technical success rate of TAE for the treatment of bleeding from the hepatic resection margin, hepatic artery anastomotic site and hepaticojejunostomy was only 18% (2/11), whereas for the treatment of bleeding in the other locations the technical and clinical success rates of TAE were 100% and 95%, respectively. No procedure-related major complications occurred.

Conclusion

In the case of arterial bleeding after LDLT, percutaneous procedure-related hemorrhages were as common as surgery-related hemorrhages. There were technical difficulties in using TAE for the treatment of hepatic arterial bleeding. However, in the other locations, TAE seems to be safe and effective for the control of arterial bleeding in LDLT recipients.

Differences in Attitude Toward Living and Postmortal Liver Donation in the United States, Germany, and Japan

Living liver donation is a possible immediate option for decreasing the shortage of liver allografts worldwide. Risks related to the donation make this procedure ethically controversial. Study groups of medical students (N= 330) from three different nations were analyzed with a complex questionnaire, and data were subjected to multiparameter analysis. The readiness for living liver donation was dependent upon the cultural background of the study groups. It was higher in the U.S. than in Germany and Japan, with a higher donation readiness for children as recipients than adults. Major differences among distinct sociodemographic groups need to be carefully addressed when setting up consensus guidelines for the clinical practice of living donation.

Protection of reduced-size liver for transplantation

The shortage of available organs for liver transplantation has motivated the development of new surgical techniques such as reduced-size liver transplantation. Ischemia-reperfusion (I/R) associated with liver transplantation impairs liver regeneration. Ischemic preconditioning is effective against I/R injury in clinical practice of liver tumour resections. The present study evaluated the effect of ischemic preconditioning on reduced-size liver for transplantation and attempted to identify the underlying protective mechanisms. Hepatic injury and regeneration (transaminases, proliferating cell nuclear antigen [PCNA] labeling index, and hepatocyte growth factor [HGF]) were assessed after reduced-size orthotopic liver transplantation (ROLT). Energy metabolism, oxidative stress, tumor necrosis factor-alpha (TNF) and interleukin-6 (IL-6) were examined as possible mechanisms involved in liver regeneration. Ischemic preconditioning reduced transaminase levels and increased HGF levels and the percentage of PCNA-positive hepatocytes after ROLT. This was associated with a decrease in oxidative stress following ROLT, whereas energy metabolism and hepatic IL-6 and TNF release were unchanged. The benefits of ischemic preconditioning on hepatic injury and liver regeneration could be mediated, at least partially by nitric oxide. These results suggest a new potential application of ischemic preconditioning in reduced-size liver transplantation.

Induction of antigen-specific immunologic tolerance by in vivo and in vitro antigen-specific expansion of naturally arising Foxp3+CD25+CD4+ regulatory T cells

Naturally arising CD25(+)CD4(+) regulatory T (T(R)) cells can be exploited to establish immunologic tolerance to non-self antigens. In vivo exposure of CD25(+)CD4(+) T cells from normal naive mice to alloantigen in a T cell-deficient environment elicited spontaneous expansion of alloantigen-specific CD25(+)CD4(+) T(R) cells, which suppressed allograft rejection mediated by subsequently transferred naive T cells, leading to long-term graft tolerance. The expanded T(R) cells, which became CD25(low) in the absence of other T cells, stably sustained suppressive activity, maintained expression levels of other T(R) cell-associated molecules, including Foxp3, CTLA-4 and GITR, and could adoptively transfer tolerance to normal mice. Furthermore, specific removal of the T(R) cells derived from originally transferred CD25(+)CD4(+) T(R) cells evoked graft rejection in the long-term tolerant mice, indicating that any T(R) cells deriving from CD25(-)CD4(+) naive T cells minimally contribute to graft tolerance and that natural T(R) cells are unable to infectiously confer significant suppressive activity to other T cells. Similar antigen-specific expansion of T(R) cells can also be achieved in vitro by stimulating naturally present CD25(+)CD4(+) T cells with alloantigen in the presence of IL-2. The expanded CD25(+)CD4(+) T cells potently suppressed even secondary MLR in vitro and, by in vivo transfer, established antigen-specific long-term graft tolerance. Thus, in vivo or in vitro, direct or indirect ways of antigen-specific expansion of naturally arising Foxp3(+)CD25(+)CD4(+) T(R) cells can establish antigen-specific dominant tolerance to non-self antigens, and would also be instrumental in re-establishing self-tolerance in autoimmune disease and antigen-specific negative control of pathological immune responses.

Long-term quality of life issues among adult-to-pediatric living liver donors: a qualitative exploration

Use of live donors as a source of transplantable livers has expanded to include adult recipients. Follow-up reports concerning living donor experiences are short-term and primarily focus on medical outcomes. We present our quality of life findings from a purposive sampling of a cohort of adult-to-pediatric live liver donors, 3-10 years after donation. In-depth interviews conducted among 15 live donors revealed the spectrum of complexity and impact that donation had on the donors. Virtually all donors (14/15) reported that they never really made a decision to donate; rather, agreeing to donate was an automatic leap. Overall, 10 out of the 15 donors related a sense that they were considered nonpatients by the medical team and family members in two primary areas: post operative treatment of pain (6/15) and long-term follow-up care (9/15) with five donors reporting concerns in both areas. Overall, family relationships were believed to have been strengthened by the donation process. Most donors experienced some degree of financial strain with three donors maintaining unrewarding employment to continue healthcare insurance. The majority of donors reported that return to normalcy took a significant amount of time even though no serious medical consequences were experienced. These observations serve to highlight some of the long-term quality of life issues that persist beyond the medical consequences of live donation.

Evaluation of living liver donors

As a result of the cadaveric organ shortage, the number of centers performing living donor liver transplantation has increased. Living donor liver transplantation provides immediate organ availability and avoids the risk of life-threatening complications that occur with long waiting times for cadaveric organs; however, it puts a healthy person at risk for little personal gain. A standardized approach to donor evaluation ensures safety to potential donors. Careful medical (physical examination as well as laboratory and radiological evaluation) and psychological evaluation is imperative to reduce donor complications and ensure good outcomes in recipients. A social worker and psychiatrist assess for mental competency, provide emotional support, and can serve as independent donor advocates. Informed understanding and consent are crucial aspects of the evaluation and include ensuring that the donor understands all potential complications and is free of coercion. Safety of the donor must be the highest priority.

Clinical and ethnic differences in candidates listed for liver transplantation with and without potential living donors

The shortage of cadaver livers and improved outcomes in partial liver transplants has led to an increase in adult living donor liver transplantation (LDLT). Only a fraction of potential liver recipients have donors. The characteristics of candidates who have volunteers for living donation may be different than those without donors. We compared adult patients on the waiting list who had potential living donors with those who did not have living donors. Two-hundred and four consecutive patients were listed for transplantation. During evaluation, all were informed and educated about LDLT. To avoid coercion, we did not solicit a living donor. Sixty (29%) potential recipients had at least one living donor volunteer for evaluation. Twenty-eight (14%) patients from the entire cohort and 46% of the 60 patients who had potential living donors underwent LDLT. Compared with Caucasians, Hispanics were more likely to have living donors (P =.006). No patient with alcoholic liver disease (ALD) had a donor come forward (P =.006). Patients with living donors were twice as likely to have cancer (P =.08). Systematic differences exist between patients who have potential living donors versus those without donors. Candidates with potential donors are more likely to be Hispanic and have cancer and less likely to have ALD compared with cadaveric recipients. Only a minority of patients listed for orthotopic liver transplantation (OLT) will lead to LDLT. Further understanding of the cultural differences and motivating factors for why people volunteer for evaluation and subsequently choose to donate may help improve cadaveric and living donor transplant rates.

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.