The real incidence of biliary tract complications after adult liver transplantation: the role of the prospective routine use of cholangiography during post-transplant follow-up

Advancing immunosuppression in liver transplantation: A narrative review

Immunosuppression is essential to ensure recipient and graft survivals after liver transplantation (LT). However, our understanding and management of the immune system remain suboptimal. Current immunosuppressive therapy cannot selectively inhibit the graft-specific immune response and entails a significant risk of serious side effects, i.e., among others, de novo cancers, infections, cardiovascular events, renal failure, metabolic syndrome, and late graft fibrosis, with progressive loss of graft function. Pharmacological research, aimed to develop alternative immunosuppressive agents in LT, is behind other solid-organ transplantation subspecialties, and, therefore, the development of new compounds and strategies should get priority in LT. The research trajectories cover mechanisms to induce T-cell exhaustion, to inhibit co-stimulation, to mitigate non-antigen-specific inflammatory response, and, lastly, to minimize the development and action of donor-specific antibodies. Moreover, while cellular modulation techniques are complex, active research is underway to foster the action of T-regulatory cells, to induce tolerogenic dendritic cells, and to promote the function of B-regulatory cells. We herein discuss current lines of research in clinical immunosuppression, particularly focusing on possible applications in the LT setting.

Biliary Complications After Liver Transplantation in the United States: Changing Trends and Economic Implications

BACKGROUND

Biliary complications (BCs) continue to impact patient and graft survival after liver transplant (LT), despite improvements in organ preservation, surgical technique, and posttransplant care. Real-world evidence provides a national estimate of the incidence of BC after LT, implications for patient and graft outcomes, and attributable cost not available in transplant registry data.

METHODS

An administrative health claims-based BC identification algorithm was validated using electronic health records (N = 128) and then applied to nationally linked Medicare and transplant registry claims.

RESULTS

The real-world evidence algorithm identified 97% of BCs in the electronic health record review. Nationally, the incidence of BCs within 1 y of LT appears to have improved from 22.2% in 2002 to 20.8% in 2018. Factors associated with BCs include donor type (living versus deceased), recipient age, diagnosis, prior transplant, donor age, and donor cause of death. BCs increased the risk-adjusted hazard ratio (aHR) for posttransplant death (aHR, 1.43; P < 0.0001) and graft loss (aHR, 1.48; P < 0.0001). Nationally, BCs requiring intervention increased risk-adjusted first-year Medicare spending by $39 710 (P < 0.0001).

CONCLUSIONS

BCs remain an important cause of morbidity and expense after LT and would benefit from a systematic quality-improvement program.

Scheduled endoscopic treatment of biliary anastomotic and nonanastomotic strictures after orthotopic liver transplantation

BACKGROUND AND AIMS

Biliary strictures after liver transplantation are associated with significant morbidity and mortality. Although various endoscopic treatment strategies are available, consensus on a particular strategy is lacking. Moreover, the influence of endoscopic therapy on overall survival has not been studied. This retrospective study aimed to evaluate the impact of scheduled endoscopic dilatation of biliary strictures after orthotopic liver transplantation on therapeutic success, adverse events, and survival.

METHODS

Between 2000 and 2016, patients with post-transplant anastomotic and nonanastomotic strictures were treated with balloon dilatation at defined intervals until morphologic resolution and clinical improvement. The primary clinical endpoint was overall survival, whereas secondary outcomes were technical and sustained clinical success, adverse events, treatment failure, and recurrence.

RESULTS

Overall, 165 patients with a mean follow-up of 8 years were included; anastomotic and nonanastomotic strictures were diagnosed in 110 and 55 patients, respectively. Overall survival was significantly higher in patients with anastomotic strictures than in those with nonanastomotic strictures (median, 17.6 vs 13.9 years; log-rank: P < .05). Sustained clinical success could be achieved significantly more frequently in patients with anastomotic strictures (79.1% vs 54.5%, P < .001), and such patients showed significantly superior overall survival (19.7 vs 7.7 years; log-rank: P < .001). Sustained clinical success and the presence of nonanastomotic strictures were independently associated with better and worse outcomes (P < .05), respectively.

CONCLUSIONS

Scheduled endoscopic treatment of biliary anastomotic and nonanastomotic strictures after liver transplantation is effective and safe, with high success rates. The implementation of this strategy controls symptoms and significantly improves survival.

Recipient and Center Factors Associated With Immunosuppression Practice Beyond the First Year After Liver Transplantation and Impact on Outcomes

BACKGROUND

Immunosuppression is a critical aspect of post-transplant management, yet practices at intermediate and late time points after liver transplantation (LT) are poorly characterized.

METHODS

A retrospective cohort of 11 326 adult first LT alone recipients between 2007 and 2016 was identified by linking United Network for Organ Sharing transplant data to Medicare administrative claims. The immunosuppression regimen was obtained from Medicare billing claims. Factors associated with calcineurin inhibitor (CNI) monotherapy at 1-, 3-, and 5-y post-LT were investigated using mixed-effects logistic regression. Center practice heterogeneity was evaluated. The association of immunosuppression regimen (time-updating) with patient and graft survival was studied.

RESULTS

CNI monotherapy was used in 51.9% at 1-y post-LT and 68.6% at 5-y post-LT. Center-specific rates ranged from 20.0%-79.9% to 15.4%-95.2%, respectively. CNI monotherapy at 1- and 3-y post-LT was less likely among Black recipients ( P = 0.027 and P = 0.015 versus White, respectively). CNI plus antimetabolite was associated with improved adjusted patient (hazard ratio, 0.59; P < 0.001) and graft (hazard ratio, 0.62; P < 0.001) survival versus CNI monotherapy. The benefit of CNI plus antimetabolite on patient and graft survival increased with older age.

CONCLUSIONS

In this first longitudinal analysis of LT immunosuppression practices among Medicare beneficiaries, a CNI plus antimetabolite approach led to improved outcomes. Significant center heterogeneity in practice was observed.

Liver perfusion strategies: what is best and do ischemia times still matter?

PURPOSE OF REVIEW

This review describes recent developments in the field of liver perfusion techniques.

RECENT FINDINGS

Dynamic preservation techniques are increasingly tested due to the urgent need to improve the overall poor donor utilization. With their exposure to warm ischemia, livers from donors after circulatory death (DCD) transmit additional risk for severe complications after transplantation. Although the superiority of dynamic approaches compared to static-cold-storage is widely accepted, the number of good quality studies remains limited. Most risk factors, particularly donor warm ischemia, and accepted thresholds are inconsistently reported, leading to difficulties to assess the impact of new preservation technologies. Normothermic regional perfusion (NRP) leads to good outcomes after DCD liver transplantation, with however short ischemia times. While randomized controlled trials (RCT) with NRP are lacking, results from the first RCTs with ex-situ perfusion were reported. Hypothermic oxygenated perfusion was shown to protect DCD liver recipients from ischemic cholangiopathy. In contrast, endischemic normothermic perfusion seems to not impact on the development of biliary complications, although this evidence is only available from retrospective studies.

SUMMARY

Dynamic perfusion strategies impact posttransplant outcomes and are increasingly commissioned in various countries along with more evidence from RCTs. Transparent reporting of risk and utilization with uniform definitions is required to compare the role of different preservation strategies in DCD livers with prolonged ischemia times.

Immunosuppression in liver and intestinal transplantation

Immunosuppression handling plays a key role in the early and long-term results of transplantation. The development of multiple immunosuppressive drugs led to numerous clincial trials searching to reach the ideal regimen. Due to heterogeneity of the studied patient cohorts and flaws in many, even randomized controlled, study designs, the answer still stands out. Nowadays triple-drug immunosuppression containing a calcineurin inhibitor (preferentially tacrolimus), an antimetabolite (using mycophenolate moffettil or Azathioprine) and short-term steroids with or without induction therapy (using anti-IL2 receptor blocker or anti-lymphocytic serum) is the preferred option in both liver and intestinal transplantation. This chapter aims, based on a critical review of the definitions of rejection, corticoresistant rejection and standard immunosuppression to give some reflections on how to reach an optimal immunosuppressive status and to conduct trials allowing to draw solid conclusions. Endpoints of future trials should not anymore focus on biopsy proven, acute and chronic, rejection but also on graft and patient survival. Correlation between early- and long-term biologic, immunologic and histopathologic findings will be fundamental to reach in much more patients the status of operational tolerance.