Impact of pretransplant renal failure: when is listing for kidney-liver indicated?

Analysis of Native Kidney Function Recovery With Renal Scintigraphy Following Simultaneous Liver-Kidney Transplantation

BACKGROUND

Patients undergoing simultaneous liver-kidney transplantation (SLK) have impaired native kidney function. The relative contribution of allograft versus native function after SLK is unknown. We sought to characterize the return of native kidney function following SLK.

METHODS

Following SLK, patients underwent technetium-99 m-mercaptoacetyltriglycine renal scintigraphy following serum creatinine nadir. Kidney contributions to estimated glomerular filtration rate (eGFR) were determined. Patients with native kidney function at serum creatinine nadir contributing eGFR ≥30 versus <30 mL/min/1.73 m 2 were compared, and multiple linear regression analysis for native eGFR improvement was performed.

RESULTS

Thirty-one patients were included in this analysis. Average native kidney contribution to overall kidney function following SLK was 51.1% corresponding to native kidney eGFR of 44.5 mL/min/1.73 m 2 and native kidney function eGFR improvement of 30.3 mL/min/1.73 m 2 ( P < 0.001). Twenty-six of 31 patients had native kidney contribution of eGFR ≥30 mL/min/1.73 m 2 . Hepatorenal syndrome as the sole primary etiology of kidney dysfunction was 100% specific for native kidney eGFR >30 mL/min/1.73 m 2 and predicted native eGFR improvement ( P = 0.03).

CONCLUSIONS

Substantial improvement in native kidney function follows SLK, and hepatorenal syndrome as the sole primary etiology of kidney dysfunction is predictive of improvement. Whether such patients are suitable for liver transplant followed by surveillance with option for subsequent kidney transplants requires investigation.

A meta-analysis on the prevalence of chronic kidney disease in liver transplant candidates and its associated risk factors and outcomes

Pre-liver transplant (LT) chronic kidney disease (CKD) has emerged as a leading cause of post-operative morbidity. We aimed to report the prevalence, associated risk factors, and clinical outcomes in patients with pre-LT CKD. Meta-analysis and systematic review were conducted for included cohort and cross-sectional studies. Studies comparing healthy and patients with s pre-LT CKD were included. Outcomes were assessed with pooled hazard ratios. 15 studies were included, consisting of 82,432 LT patients and 26,754 with pre-LT CKD. Pooled prevalence of pre-LT CKD was 22.35% (CI: 15.30%-32.71%). Diabetes mellitus, hypertension, viral hepatitis, and non-alcoholic fatty liver disease, and older age were associated with increased risk of pre-LT CKD: (OR 1.72 CI: 1.15-2.56, P = 0.01), (OR 2.23 CI: 1.76-2.83, P < 0.01), (OR 1.09; CI: 1.05-1.13, P < 0.01), (OR 1.73; CI: 1.10-2.71 P = 0.03), and (MD: 2.92 years; CI: 1.29-4.55years; P < 0.01) respectively. Pre-LT CKD was significantly associated with increased mortality (HR 1.38; CI: 1.2-1.59; P < 0.01), post-LT end-stage renal disease and post-LT CKD. Almost a quarter of pre-LT patients have CKD and it is significantly associated with post-operative morbidity and mortality. However, long-term outcomes remain unclear due to a lack of studies reporting such outcomes.

Current and Evolving Indications for Simultaneous Liver Kidney Transplantation

This review will discuss the etiologies of kidney disease in liver transplant candidates, provide a historical background of the prior evolution of simultaneous liver-kidney (SLK) transplant indications, discuss the current indications for SLK including Organ Procurement and Transplantation Network policies and Model for End Stage Liver Disease exception points, as well as provide an overview of the safety net kidney transplant policy. Finally, the authors explore unanswered questions and future research needed in SLK transplantation.

Optimizing the Selection of Patients for Simultaneous Liver-Kidney Transplant

Simultaneous liver-kidney transplantation has increased significantly in the Model for End Stage Liver Disease era. The transplantation policy has evolved significantly since the implementation of allocation based on the Model for End Stage Liver Disease. Current policy takes into account the medical eligibility criteria for simultaneous liver-kidney transplantation listing. It also provides a safety net option and prioritizes kidney transplant after liver transplant recipients who are unlikely to recover their renal function within 60 to 365 days after liver transplant alone. This review seeks to understand the underlying challenges in carefully selecting the candidates while optimizing the patient selection.

Combined liver and kidney transplantation in children and long-term outcome

Combined liver-kidney transplantation (CLKT) is a rarely performed complex surgical procedure in children and involves transplantation of kidney and either whole or part of liver donated by the same individual (usually a cadaver) to the same recipient during a single surgical procedure. Most common indications for CLKT in children are autosomal recessive polycystic kidney disease and primary hyperoxaluria type 1. Atypical haemolytic uremic syndrome, methylmalonic academia, and conditions where liver and renal failure co-exists may be indications for CLKT. CLKT is often preferred over sequential liver-kidney transplantation due to immunoprotective effects of transplanted liver on renal allograft; however, liver survival has no significant impact. Since CLKT is a major surgical procedure which involves multiple and complex anastomosis surgeries, acute complications are not uncommon. Bleeding, thrombosis, haemodynamic instability, infections, acute cellular rejections, renal and liver dysfunction are acute complications. The long-term outlook is promising with over 80% 5-year survival rates among those children who survive the initial six-month postoperative period.

Medical care of liver transplant patients

INTRODUCTION

Liver transplantation is a life-changing event for patients and survival following transplantation has improved significantly since the first transplantation in 1967. Following liver transplantation, patients face a unique set of healthcare management decisions including transplantation-specific complications, recurrence of primary liver disease, as well as metabolic and malignancy concerns related to immunosuppression. As more patients with liver disease receive transplantation and live longer, understanding and managing these patients will require not only transplant specialist but also local subspecialist and primary care physicians.

AREAS COVERED

This review covers common issues related to the management of patients following liver transplantation including immunosuppression, liver allograft dysfunction, metabolic complications, as well as routine health maintenance such as immunizations and cancer screening.

EXPERT OPINION

Optimizing medical care for patients following liver transplant will benefit from ensuring all providers, not just transplant specialist, have a basic understanding of the common issues encountered in the post-transplant patient. This review provides an overview of common healthcare concerns and management options for patients following liver transplantation.

Effect of Renal Diagnosis on Survival in Simultaneous Liver-Kidney Transplantation

BACKGROUND

Simultaneous liver-kidney transplantation is lifesaving, however, the utility of allocating 2 organs to a single recipient remains controversial, particularly in the face of potentially inferior survival. This study aims to determine the effect of renal indication for transplantation on simultaneous liver-kidney transplantation outcomes.

METHODS

All adult recipients of combined whole liver-kidney transplants in the United Network for Organ Sharing database from 2003 to 2016 with a renal diagnosis of hypertension (HTN), diabetes mellitus (DM), acute tubular necrosis (ATN), or hepatorenal syndrome (HRS) were examined. Comparisons were made between the HTN/DM group and the ATN/HRS group using standard statistical methods.

RESULTS

There were 1,204 patients in the HRS/ATN group vs 1,272 patients in the HTN/DM group. The HTN/DM patients were slightly older (58.1 vs 56.4 years; p < 0.001), more likely to have liver disease due to chronic viral hepatitis (33.2% vs 21.5%; p < 0.001), and less acutely ill (mean Model for End-Stage Liver Disease score of 27.2 vs 33.1; p < 0.001) than their HRS/ATN counterparts. The prevalence of nonalcoholic steatohepatitis was 16.8% in both groups. Donor demographics were similar in both groups, although HTN/DM patients were more likely to have a local (81.6% vs 67.7%; p < 0.001) rather than regional donor. Patient survival rates at 1, 3, and 5 years were significantly lower in the HTN/DM group (87.4%, 78.2%, and 71.2% vs 90.7%, 84.1%, and 76.6%, respectively). Median survival was 118 months for the HTN/DM group vs 139.7 months for the HRS/ATN (p < 0.001). The HTN/DM patients were at significantly higher risk of death (hazard ratio 1.533; p < 0.001), liver graft loss (hazard ratio 1.611; p < 0.001), and renal graft loss (hazard ratio 1.592; p < 0.001) than ATN/HRS patients on multivariable analysis.

CONCLUSIONS

Despite a lower acuity of illness, HTN/DM patients have inferior survival after simultaneous liver-kidney transplantation than those with ATN/HRS. This should be considered in risk adjustment and allocation schemes.

Renal transplantation in autosomal dominant polycystic kidney disease

In patients with autosomal dominant polycystic kidney disease (ADPKD) evaluated for kidney transplantation, issues related to native nephrectomy, cystic liver involvement, screening for intracranial aneurysms and living-related kidney donation deserve special consideration. Prophylactic native nephrectomy is restricted to patients with a history of cyst infection or recurrent haemorrhage or to those in whom space must be made to implant the graft. Patients with liver involvement require pretransplant imaging. Selection of patients for pretransplant screening of intracranial aneurysms should follow the general recommendations for patients with ADPKD. In living related-donor candidates aged <30 years and at-risk of ADPKD, molecular genetic testing should be carried out when ultrasonography and MRI findings are normal or equivocal. After kidney transplantation, patient and graft survival rates are excellent and the volume of native kidneys decreases. However, liver cysts continue to grow and treatment with a somatostatin analogue should be considered in patients with massive cyst involvement. Cerebrovascular events have a marginal effect on post-transplant morbidity and mortality. An increased risk of new-onset diabetes mellitus and nonmelanoma skin cancers has been reported, but several studies have challenged these findings. Finally, no data currently support the preferential use of mammalian target of rapamycin inhibitors as immunosuppressive agents in transplant recipients with ADPKD.

Outcomes and native renal recovery following simultaneous liver-kidney transplantation

With the increase in patients having impaired renal function at liver transplant due to MELD, accurate predictors of posttransplant native renal recovery are needed to select candidates for simultaneous liver-kidney transplantation (SLK). Current UNOS guidelines rely on specific clinical criteria for SLK allocation. To examine these guidelines and other variables predicting nonrecovery, we analyzed 155 SLK recipients, focusing on a subset (n = 78) that had post-SLK native GFR (nGFR) determined by radionuclide renal scans. The 77 patients not having renal scans received a higher number of extended criteria donor organs and had worse posttransplant survival. Of the 78 renal scan patients, 31 met and 47 did not meet pre-SLK UNOS criteria. The UNOS criteria were more predictive than our institutional criteria for all nGFR recovery thresholds (20-40 mL/min), although at the most conservative cut-off (nGFR ≤ 20) it had low sensitivity (55.3%), specificity (75%), PPV (67.6%) and NPV (63.8%) for predicting post-SLK nonrecovery. On multivariate analysis, the only predictor of native renal nonrecovery (nGFR ≤ 20) was abnormal pre-SLK renal imaging (OR 3.85, CI 1.22-12.5). Our data support the need to refine SLK selection utilizing more definitive biomarkers and predictors of native renal recovery than current clinical criteria.

Long-term medical management of the liver transplant recipient: what the primary care physician needs to know

Recognition, management, and prevention of medical complications and comorbidities after liver transplant is the key to improved long-term outcomes. Beyond allograft-related complications, metabolic syndrome, cardiovascular disease, renal dysfunction, and malignancies are leading causes of morbidity and mortality in this patient population. Primary care physicians have an important role in improving outcomes of liver transplant recipients and are increasingly relied on for managing these complex patients. This review serves to assist the primary care physician in the long-term management issues of liver transplant recipients.

Outcomes of simultaneous liver/kidney transplants are equivalent to kidney transplant alone: a preliminary report

BACKGROUND

With adoption of Model for End-Stage Liver Disease, the number of simultaneous liver-kidney transplants (SLK) has greatly increased. A recent registry study questioned the equity of allocating kidney transplants (KTx) simultaneously with liver transplantation due to poor outcomes (Locke et al., Transplantation 2008; 85: 935).

METHODS

To investigate outcome of KTx in SLK, all SLK (n=36) performed at our center from January 2000 to December 2007 were reviewed and KTx outcomes compared with those of kidney transplant alone (KTA) performed during that period (n=1283). We also reviewed whether pretransplant panel reactive antibody and donor-specific antibody affected KTx outcome in SLK.

RESULTS

One- and 3-year KTx and patient survival were not different between KTA and SLK regardless of sensitization level. There were 348 (27%) KTx failures in KTA vs. 6 (17%) in SLK (NS). Overall freedom from acute cellular rejection (ACR) and antibody-mediated rejection (AMR) in SLK was 93 and 96% at 3 years, compared with 72 and 78% in KTA (P=0.0105 and P=0.0744, respectively). Sensitized KTx recipients had more ACR and AMR (32 and 38%) at 3 years compared with nonsensitized recipients (28 and 20%) (P=0.23 and 0.0001, respectively). No differences in ACR and AMR were observed when SLK was divided and level of sensitization compared (P=0.17 and 0.65, respectively).

CONCLUSION

SLK is a life-saving procedure with excellent patient and graft survival. AMR incidence in the KTx appears reduced in SLK compared with KTA regardless of level of preoperative panel reactive antibody. A high level of donor-specific antibody should not preclude simultaneous transplantation when clinically indicated.

Renal failure in patients with cirrhosis: hepatorenal syndrome and renal support strategies

PURPOSE OF REVIEW

The development of hepatorenal syndrome in liver cirrhosis leads to an increased morbidity and mortality in patients with cirrhosis. Currently, there are no proven methods for the treatment or prevention of hepatorenal syndrome except to maintain adequate hemodynamics and intravascular volume in this patient population. These patients will frequently require renal replacement therapy when presenting for hepatic transplantation.

RECENT FINDINGS

New consensus definitions have been published in order to create uniform standards for classifying and diagnosing acute kidney injury. Two such groups are the Acute Dialysis Quality Initiative (ADQI) and the Acute Kidney Injury Network (AKIN), which have proposed approaches to defining criteria for acute kidney injury. Recent literature supports not only the role of splanchnic vasodilation and systemic vasoconstriction but also heart failure in the pathogenesis of hepatorenal syndrome. The practice of using vasoconstrictor and intravenous albumin therapy for the treatment of hepatorenal syndrome is ongoing with a growing body of recent data supporting the use of vasopressin analogs as the first-line therapy in the ICU setting with knowledge of the possible cardiovascular side-effects.

SUMMARY

Hepatorenal syndrome, HRS, is a diagnosis of exclusion. There are two forms of hepatorenal syndrome: type 1 hepatorenal syndrome and type 2 hepatorenal syndrome. Type 1 HRS is rapidly progressive and portends a very poor prognosis and has a high mortality rate. Type 2 is more indolent while still associated with an overall poor prognosis. Treatment of HRS is largely still supportive. It is imperative to maintain euvolemia and hemodynamics in this patient population to optimize renal perfusion and preserve renal function. Renal replacement therapy may be necessary in this chronically ill patient population, if renal function deteriorates such that the kidneys cannot maintain metabolic and volume homeostasis. Further research is still necessary as to the prevention and effective treatment for hepatorenal syndrome.

A single center experience of combined liver kidney transplantation

With advancements in the operative techniques, patient survival following liver transplantation (LTx) has increased substantially. This has led to the acceleration of pre-existing kidney disease because of immunosuppressive nephrotoxicity making additional kidney transplantation (KTx) inevitable. On the other hand, in a growing number of patients on the waiting list to receive liver, long waiting time has resulted in adverse effect of decompensated liver on the kidney function. During the last two decades, the transplant community has considered combined liver kidney transplantation (CLKTx) to overcome this problem. The aim of our study is to present an overview of our experience as well as a review of the literature in CLKTx and to discuss the controversy in this regard. All performed CLKTx (n = 22) at our institution as well as all available reported case series focusing on CLKTx are extracted. The references of the manuscripts were cross-checked to implement further articles into the review. The analyzed parameters include demographic data, indication for LTx and KTx, duration on the waiting list, Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, immunosuppressive regimen, post-transplant complications, graft and patient survival, and cause of death. From 1988 to 2009, a total of 22 CLKTx were performed at our institution. The median age of the patients at the time of CLKTx was 44.8 (range: 4.5-58.3 yr). The indications for LTx were liver cirrhosis, hyperoxaluria type 1, polycystic liver disease, primary or secondary sclerosing cholangitis, malignant hepatic epithelioid hemangioendothelioma, cystinosis, and congenital biliary fibrosis. The KTx indications were end-stage renal disease of various causes, hyperoxaluria type 1, polycystic kidney disease, and cystinosis. The mean follow-up duration for CLKTx patients were 4.6 +/- 3.5 yr (range: 0.5-12 yr). Overall, the most important encountered complications were sepsis (n = 8), liver failure leading to retransplantation (n = 4), liver rejection (n = 3), and kidney rejection (n = 1). The overall patient survival rate was 80%. Review of the literature showed that from 1984 to 2008, 3536 CLKTx cases were reported. The main indications for CLKTx were oxalosis of both organs, liver cirrhosis and chronic renal failure, polycystic liver and kidney disease, and liver cirrhosis along with hepatorenal syndrome (HRS). The most common encountered complications following CLKTx were infection, bleeding, biliary complications, retransplantation of the liver, acute hepatic artery thrombosis, and retransplantation of the kidney. From the available data regarding the need for post-operative dialysis (n = 673), a total of 175 recipients (26%) required hemodialysis. During the follow-up period, 154 episodes of liver rejection (4.3%) and 113 episodes of kidney rejection (3.2%) occurred. The cumulative 1, 2, 3, and 5 yr survival of both organs were 78.2%, 74.4%, 62.4%, and 60.9%, respectively. Additionally, the cumulative 1, 2, 3, and 5 yr patient survival were 84.9%, 52.8%, 45.4%, and 42.6%, respectively. The total number of reported deaths was 181 of 2808 cases (6.4%), from them the cause of death in 99 (55%) cases was sepsis. It can be concluded that there is still no definitive evidence of better graft and patient survival in CLKTx recipients when compared with LTx alone because of the complexity of the exact definition of irreversible kidney function in LTx candidates. Additionally, CLKTx is better to be performed earlier than isolated LTx and KTx leading to the avoidance of deterioration of clinical status, high rate of graft loss, and mortality. Shorter graft ischemia time and more effective immunosuppressive regimens can reduce the incidence of graft malfunctioning in CLKTx patients. Providing a model to reliably determine the need for CLKTx seems necessary. Such a model can be shaped based upon new and precise markers of renal function, and modification of MELD system.

Pretransplant predictors of recovery of renal function after liver transplantation

The Model for End-Stage Liver Disease system has given priority on the liver transplant waiting list to candidates with renal failure. This study determined the predictors of spontaneous recovery of renal function after transplantation in 1041 liver transplant recipients on renal replacement therapy (RRT) at the time of transplant (from February 2002 to January 2007). Data from these patients were obtained from the US Organ Procurement and Transplantation Network and US Renal Data System databases. Univariate and multivariate survival models were constructed along with multivariate logistic regression models to find independent predictors of spontaneous renal recovery. Seven hundred seven recipients (67.9%) had spontaneous recovery of renal function after liver transplantation. Those recovering spontaneously had a significantly shorter course of RRT in the pretransplant time period (15.6 versus 36.6 days, P < 0.001). Recovery of renal function was observed in 70.8% and 11.5% of recipients on RRT for less than 30 days and more than 90 days, respectively. Other statistically significant pretransplant variables independently associated with recovery of renal function included recipient age, recipient pretransplant diabetes, and donor age. In conclusion, the duration of pretransplant RRT is highly predictive of spontaneous renal recovery post-transplant. Liver transplant candidates requiring less than 30 days of pretransplant RRT are likely to spontaneously recover renal function after liver transplantation, whereas those on RRT for more than 90 days are not.

Treatment of hepatorenal syndrome

Hepatorenal syndrome (HRS) is a type of renal failure that occurs in patients with advanced cirrhosis. It is a result of splanchnic arterial vasodilation, renal vasoconstriction, reduced effective arterial volume, and potentially reduced cardiac output. Often, HRS is a fatal complication, and the only definitive treatment currently available is liver or liver-kidney transplantation. A number of other treatment modalities have been tested for the management of HRS, but most evidence is derived from small noncontrolled studies. The primary role of these treatment options is to provide a bridge to liver transplantation. Treatment may also provide acute reversal of renal failure and some symptomatic relief, but relapse is a common occurrence. The best therapeutic options appear to be those that reverse portal hypertension, splanchnic vasodilation, and/or renal vasoconstriction. Vasopressin analogs, particularly terlipressin, have emerged as the preferred pharmacologic therapies for management of HRS. Albumin is an appropriate adjunctive therapy to terlipressin and can be used to prevent HRS in patients with spontaneous bacterial peritonitis. Transjugular intrahepatic portosystemic shunt may provide a surgical option for qualified patients with HRS. Octreotide is ineffective as monotherapy but may be used as adjunctive therapy to other vasoactive agents. Dopamine agonists, endothelin antagonists, natriuretic peptides, and nitric oxide synthase inhibitors have not been effective for reversing HRS. Artificial hepatic support therapies have demonstrated the ability to improve laboratory abnormalities in patients with HRS, but their effect on clinical outcomes has not been determined. The role of renal replacement therapies or the newer artificial hepatic support therapies need further evaluation before they can be routinely recommended.

Indications for combined liver and kidney transplantation in children

A significant number of patients awaiting liver transplantation have associated renal failure and renal dysfunction is associated with increased morbidity and mortality after LT. There has been a recent increase in the number of CLKT in adults. The common indications for CLKT in children are different from those of adults and include metabolic diseases affecting the kidney with or without liver dysfunction and congenital developmental abnormalities affecting both organs. The results are generally encouraging among these groups of patients. Early evaluation and listing of patients before they become severely ill or have major systemic manifestations of their metabolic problem are important.

Current indications for combined liver and kidney transplantation in adults

A significant number of patients awaiting liver transplantation have associated renal failure. Combined Liver and Kidney Transplantation (CLKT) is increasingly offered especially since the introduction of Model for End-Stage Liver Disease (MELD). Decision to perform CLKT is straightforward when both organs suffer end-stage failure. However, the indications for CLKT are not well defined and there is controversy concerning some. We reviewed available data on PUBMED, United Network for Organ Sharing (UNOS), Organ Procurement Transplantation Network (OPTN), European Society for Organ Transplantation (ESOT) and discuss all current indications for CLKT.

CONCLUSION

Overall long-term outcome following CLKT is acceptable. There is an urgent need to further refine our ability to identify the cases with reversible renal injury in the setting of end-stage liver disease to avoid unnecessary CLKT. Liver protects the kidney from disease recurrence and allograft loss in metabolic diseases. However, the use of liver allograft for immunological protection of kidneys in highly sensitised patients with positive cross-match and previously failed renal transplants is still experimental.

Acute kidney injury in cirrhosis

Acute renal failure (ARF), recently renamed acute kidney injury (AKI), is a relatively frequent problem, occurring in approximately 20% of hospitalized patients with cirrhosis. Although serum creatinine may underestimate the degree of renal dysfunction in cirrhosis, measures to diagnose and treat AKI should be made in patients in whom serum creatinine rises abruptly by 0.3 mg/dL or more (>/=26.4 micromol/L) or increases by 150% or more (1.5-fold) from baseline. The most common causes of ARF (the term is used interchangeably with AKI) in cirrhosis are prerenal azotemia (volume-responsive prerenal AKI), acute tubular necrosis, and hepatorenal syndrome (HRS), a functional type of prerenal AKI exclusive of cirrhosis that does not respond to volume repletion. Because of the progressive vasodilatory state of cirrhosis that leads to relative hypovolemia and decreased renal blood flow, patients with decompensated cirrhosis are very susceptible to developing AKI with events associated with a decrease in effective arterial blood volume. HRS can occur spontaneously but is more frequently precipitated by events that worsen vasodilatation, such as spontaneous bacterial peritonitis.

CONCLUSION

Specific therapies of AKI depend on the most likely cause and mechanism. Vasoconstrictors are useful bridging therapies in HRS. Ultimately, liver transplantation is indicated in otherwise reasonable candidates in whom AKI does not resolve with specific therapy.

Kidney allocation to liver transplant candidates with renal failure of undetermined etiology: role of percutaneous renal biopsy

The feasibility, value and risk of percutaneous renal biopsy (PRB) in liver transplant candidates with renal failure are unknown. PRB was performed on 44 liver transplant candidates with renal failure of undetermined etiology and glomerular filtration rate (GFR) <40 mL/min/1.73 m(2) (n = 37) or on renal replacement therapy (RRT) (n = 7). Patients with >or=30% interstitial fibrosis (IF), >or=40% global glomerulosclerosis (gGS) and/or diffuse glomerulonephritis were approved for simultaneous-liver-kidney (SLK) transplantation. Prebiopsy GFR, urinary sodium indices, dependency on RRT and kidney size were comparable between 27 liver-transplant-alone (LTA) and 17 SLK candidates and did not relate to the biopsy diagnosis. The interobserver agreement for the degree of IF or gGS was moderate-to-excellent. After a mean of 78 +/- 67 days, 16 and 8 patients received LTA and SLK transplants. All five LTA recipients on RRT recovered kidney function after transplantation and serum creatinine was comparable between LTA and SLK recipients at last follow-up. Biopsy complications developed in 13, of these, five required intervention. PRB is feasible in liver transplant candidates with renal failure and provides reproducible histological information that does not relate to the pretransplant clinical data. Randomized studies are needed to determine if PRB can direct kidney allocation in this challenging group of liver transplant candidates.

The development of perioperative practices for liver transplantation: advances and current trends

Transplantation is a young medical specialty that has grown rapidly over the past 50 years. Anesthesiologists, surgeons and hepatologists are all essential partners in the process of determining patient outcome. Each specialty has made landmark improvements in patient outcome. However, there is still variability in practice patterns in each of the 3 major specialties. This review will use a historic perspective to explore the unique forces that shaped specific transplant practices and those that gave rise to differences in perioperative practices. Anesthesiologists and surgeons have made significant improvements in the management of blood loss, and coagulation monitoring and intervention. This has improved operative survival and early patient outcome. Perioperative survival has improved despite a worldwide shortage of donor organs and a trend to transplant sicker patients. A smaller pool of donor organs is required to meet the needs of an expanding waiting list. The innovations to reduce deaths on the transplant wait list are reviewed along with their impact on overall patient outcome. The evolving organ shortage is the pinnacle point in shaping future transplant practices. Currently, institutional-specific practices may be reinforced by the informal "tutorship" that is used to train physicians and by the resources available at each site of practice. However, there is evidence that specific intraoperative practices such as the use of a low central venous pressure, selection of vasopressors and certain surgical techniques can modify patient outcome. Further investigation is needed to determine whether the good or the bad associated with each practice prevails and in what unique circumstance.

Declining outcomes in simultaneous liver-kidney transplantation in the MELD era: ineffective usage of renal allografts

BACKGROUND

When the United Network for Organ Sharing changed its algorithm for liver allocation to the model for end-stage liver disease (MELD) system in 2002, highest priority shifted to patients with renal insufficiency as a major component of their end-stage liver disease. An unintended consequence of the new system was a rapid increase in the number of simultaneous liver-kidney transplants (SLK) being performed yearly.

METHODS

Adult recipients of deceased donor liver transplants (LT, n=19,137), kidney transplants (n=33,712), and SLK transplants (n=1,032) between 1987 and 2006 were evaluated based on United Network for Organ Sharing data. Recipients were stratified by donor subgroup, MELD score, pre- versus post-MELD era, and length of time on dialysis. Matched-control analyses were performed, and graft and patient survival were analyzed by Kaplan-Meier and Cox proportional hazards analyses.

RESULTS

MELD era outcomes demonstrate a decline in patient survival after SLK. Using matched-control analysis, we are unable to demonstrate a benefit in the SLK cohort compared with LT, despite the fact that higher quality allografts are being used for SLK. Subgroup analysis of the SLK cohort did demonstrate an increase in overall 1-year patient and liver graft survival only in those patients on long-term dialysis (> or =3 months) compared with LT (84.5% vs. 70.8%, P=0.008; hazards ratio 0.57 [95% CI 0.34, 0.95], P=0.03).

CONCLUSION

These findings suggest that SLK may be overused in the MELD era and that current prioritization of kidney grafts to those liver failure patients results in wasting of limited resources.

Controversies in liver transplantation for hepatitis C

Hepatitis C is one of the most common indications for liver transplantation in the United States, accounting for approximately 40%-45% of all liver transplants. Unfortunately, recurrent disease is universal in patients who are viremic before transplantation. This can lead to cirrhosis in at least 25% of patients 5 years after liver transplantation, and recurrent hepatitis C is now emerging as an important but occasionally contentious indication for retransplantation. Several attempts have been undertaken to identify patients at high risk for severe recurrent disease who may benefit from treatment, but unfortunately antiviral therapy frequently is ineffective and often is associated with numerous side effects. Although we have made significant strides in understanding the natural history of this disease in nontransplant patients, this does not hold true for the transplant population in which several uncertainties covering virtually the entire spectrum of liver transplantation persist. Despite these concerns, on a more practical level, it is usually only in the postoperative setting that clinicians truly can assess the impact of their interventions on the natural history of recurrent hepatitis C, for example, by adjusting immunosuppression or prescribing antiviral therapy. Preoperative and perioperative (including donor) factors often are outside the control of hepatologists and transplant surgeons. This review is not an inclusive review of the literature but summarizes what we believe are the more controversial topics of this disease.

Simultaneous liver and kidney transplantation

PURPOSE OF REVIEW

The Model for End-Stage Liver Disease (MELD) scoring system for prioritizing patients for liver transplantation heavily weights serum creatinine, leading to increased numbers of liver transplant patients with renal insufficiency receiving both liver-alone transplants and liver-kidney transplants. With available organs being scarce, review of recent outcomes and guidelines for their use is timely.

RECENT FINDINGS

Despite lower average renal function in liver transplant recipients in the era of Model for End-Stage Liver Disease scoring, and poor renal function predicting inferior outcomes, overall outcomes are unchanged. Combined liver-kidney transplants have increased three-fold. Despite inferior short-term kidney and liver-graft survival rates, long-term success rates are equivalent to single-organ transplantation. Only patients requiring dialysis at the time of transplantation clearly benefit from combined liver-kidney transplants. Waitlisted patients with nonresolving severe acute kidney injury for 6-8 weeks or substantial irreversible renal parenchymal damage are also deemed appropriate candidates. Many combined liver-kidney recipients have lesser degrees of renal dysfunction, however. Accurate determination of renal function in patients with cirrhosis remains problematic.

SUMMARY

Appropriate patients with irreversible end-stage renal and liver disease clearly deserve combined liver-kidney transplants. More data on the reliable assessment of renal function, renal pathology, and outcomes are needed, however.

Chronic kidney disease after nonrenal solid-organ transplantation

Chronic kidney disease (CKD) is a common complication after nonrenal solid-organ transplantation. The risk for CKD is influenced by many factors, some of which have a direct impact on how such patients are treated in the pre-, peri-, and posttransplantation settings. This review describes hazards for acute and chronic kidney injury, with particular emphasis on calcineurin inhibitor-mediated nephrotoxicity. Rather than a detailed description of management issues that are common to the general CKD population, highlighted are aspects that are more specific to nonrenal solid-organ transplant recipients with a focus on liver, heart, and lung recipients. Strategies to minimize nephrotoxic insults and retard progressive renal injury are discussed, as are issues that are pertinent to dialysis and transplantation. Finally, future approaches to prevent and treat CKD without compromising function of the transplanted organ are addressed.

Renal function outcomes following liver transplantation and combined liver–kidney transplantation

Acute renal failure (ARF) is common immediately after orthotopic liver transplantation (OLT), whereas the incidences of chronic kidney disease (CKD) and end-stage renal disease increase with time. Introduction of the Model for End-stage Liver Disease (MELD) score-intended to prioritize patients with more-severe pretransplantation liver disease in general, and worse pretransplantation renal function in particular-for the allocation of liver grafts led to concerns about compromised patient and allograft survival and increased incidence of postoperative ARF and CKD. Nonetheless, it has been suggested that early OLT of candidates with baseline renal dysfunction improves post-transplantation renal outcomes. For OLT candidates with mild to moderate chronic renal impairment or recent-onset ARF, the decision of whether to perform OLT alone or combined liver-kidney transplantation (CLKT) can be challenging because no single factor has been shown to be predictive of the degree of renal function recovery or CKD progression following successful OLT. In this article, we provide an overview of the literature on renal function outcomes following OLT and CLKT, share our perspectives on the potential predictors of renal dysfunction or nonrecovery of renal function after OLT, and present United Network for Organ Sharing data on patient and allograft outcomes in CLKT recipients in the pre-MELD and post-MELD eras. Mechanisms that might underlie immunological protection of kidney grafts by liver allografts are also discussed.

Hepatorenal syndrome

Hepatorenal syndrome (HRS) is a “functional” and reversible form of renal failure that occurs in patients with advanced chronic liver disease. The distinctive hallmark feature of HRS is the intense renal vasoconstriction caused by interactions between systemic and portal hemodynamics. This results in activation of vasoconstrictors and suppression of vasodilators in the renal circulation. Epidemiology, pathophysiology, as well as current and emerging therapies of HRS are discussed in this review.

Simultaneous liver-kidney transplantation: evaluation to decision making

Questions about appropriate allocation of simultaneous liver and kidney transplants (SLK) are being asked because kidney dysfunction in the context of liver failure enhances access to deceased donor organs. There is specific concern that some patients who undergo combined liver and kidney transplantation may have reversible renal failure. There is also concern that liver transplants are placed prematurely in those with end-stage renal disease. Thus to assure allocation of transplants only to those truly in need, the transplant community met in March 2006 to review post-MELD (model for end-stage liver disease) data on the impact of renal function on liver waitlist and transplant outcomes and the results of SLK.

Selección de candidatos para trasplante hepático

Liver transplantation is the treatment of choice in acute and irreversible chronic liver failure of distinct etiologies. Because of the current shortage of donor organs, careful selection of candidates for transplantation is required. In addition to specific prognostic models, there are general models, such as the Child-Pugh classification and the MELD system, which are useful in determining the optimal timing of liver transplantation in most patients with cirrhosis. Once the need for transplantation has been determined and the possibility of other available therapeutic measures has been ruled out, a multidisciplinary evaluation should be performed to assess the patient's suitability for this procedure. This evaluation must rule out the presence of medical, surgical or psychological factors that could compromise patient or graft survival, making transplantation futile. The present review analyzes the most frequent contraindications to transplantation, as well as the most important aspects of pretransplantation evaluation.

Continued influence of preoperative renal function on outcome of orthotopic liver transplant (OLTX) in the US: where will MELD lead us?

Renal function is a component of the Model for End Stage Liver Disease (MELD), We queried the 1999-2004 OPTN/UNOS database to determine whether preoperative renal function remained an important determinant of survival in primary deceased donor liver transplant alone patients (DDLTA) or primary combined kidney liver transplant patients (KLTX). We examined preoperative creatinine, renal replacement therapy (RRT), incidence of KLTX, and patient survival in the 34 months before and after introduction of MELD and performed a multivariate Cox regression analysis of time to death. Preoperative renal function is an independent predictor of survival in DDLTA but not in KLTX. When compared to DDLTA with a preoperative serum creatinine of 0-0.99 mg/dL, patients with serum creatinine from 1-1.99 mg/dL, >2.0 mg/dL, those requiring RRT, and those receiving KLTX had a relative risk of death following transplant of 1.11, 1.58, 1.77, and 1.44 respectively. KLTX requiring RRT had better survival than DDLTA requiring RRT. Since introduction of MELD, KLTX, preoperative creatinine, and number of patients requiring preoperative RRT have increased. Despite this, patient survival following orthotopic liver transplant (OLTX) in the 34 months after introduction of MELD is not different than prior to introduction of MELD.

Combined liver transplants: main characteristics from the standpoint of anesthesia and support in intensive care

Combined transplants with the liver represent a small number of associated pathologies with little chance of resolving with a single transplant. The small case number prevents us from establishing homogeneous criteria for the procedure. The insertion of the Model for End-Stage Liver Disease in the preoperative evaluation of the patients awaiting liver transplant has definitely increased the number of combined liver-kidney transplants, which have reached more significant numbers. The number of heart-liver transplants is still too low to establish the efficacy of the measure. The multiorgan transplant with the liver represents a rare event entrusted to a series of case reports, each one of which has a history unto itself. Our experience in this field includes 14 combined liver-kidney, six combined heart-liver, and two multiorgan transplants with liver among 36 intestine transplants. We have examined the main pre-, intra-, and postsurgical problems for each one of these transplants, particularly relating to the anesthetic and intensive-care aspects.