Canadian Society of Transplantation White Paper: Ethical and Legal Considerations for Alcohol and Cannabis Use in Solid Organ Listing and Allocation

Cannabis use in liver transplant candidates and recipients

The increasing legality and acceptance of cannabis sale and consumption across the United States has led to a measurable increase in cannabis use nationwide, including in liver transplant (LT) candidates and recipients. With over 75% of liver transplant recipients transplanted in states with legalized use of medicinal and/or recreational cannabis, liver transplant clinicians must have expertise in the assessment of cannabis use given its potential impact on clinical care. In this review, the authors provide an understanding of nomenclature and tools to assess cannabis use, highlight essential components to guide clinical policy development and implementation, and discuss the potential impacts of cannabis use on patients' transplant course.

Cannabis use is associated with reduced access to kidney transplantation and an increased risk of acute rejection post-transplant

BACKGROUND

The association between cannabis use and access to waitlisting, transplantation, and post-transplant outcomes remains uncertain.

METHODS

Patients referred for kidney transplant (KT) to the University Health Network from January 1, 2003, to June 30, 2020, and followed until December 31, 2020, were included. Predictors of reported cannabis use were examined using a logistic regression model. The association between cannabis use and time to clearance for KT, undergoing KT, and post-transplant outcomes was evaluated using Cox proportional hazards models.

RESULTS

Among 3734 patients, the prevalence of reported cannabis use was 11.8%. Cannabis use was associated with a lower likelihood of KT clearance (adjusted hazard ratio [aHR] .82 [95% confidence interval (CI): .72, .94]). Once cleared for KT, cannabis use did not predict the subsequent receipt of KT (aHR .92, [95% CI: .79, 1.08]). Among 2091 KT recipients, cannabis use was associated with a higher likelihood of biopsy-proven acute rejection (aHR 1.55, [95% CI: 1.06, 2.27]). The relative hazard of death-censored graft failure was similarly elevated (aHR 1.60 [95% CI: .95, 2.72]). Cannabis use did not predict total graft failure (aHR 1.33 [95% CI: .90, 1.96]), death with graft function (aHR 1.06 [95% CI: .59, 1.89]), or hospital readmission in the first-year post-transplant (aHR 1.26 [95% CI: .95, 1.68]).

CONCLUSIONS

Cannabis users have less access to transplantation and an increased risk of acute rejection, possibly leading to more graft loss. Further studies are warranted to understand possible mechanisms for the increased risk of allograft immune injury among cannabis users.

Review of liver transplantation candidacy and outcomes among patients who use cannabis: Is it time for a change in policy?

Background

Recreational cannabis was legalized in Canada in 2018. A controversial contraindication for liver transplantation is cannabis. There is currently no consensus regarding cannabis use in liver transplant candidates. We aim to investigate liver transplantation candidacy and outcomes among cannabis users.

Methods

English peer-reviewed studies on PubMed and Google Scholar were searched on September 9, 2022, using keywords including "cannabis," "liver transplantation," and their synonyms. Titles and abstracts were screened, followed by full texts. Reference lists were reviewed. Studies that investigated liver transplantation candidacy and outcomes among cannabis users were included.

Results

The proportion of patients listed for liver transplantation was significantly less among cannabis users than among non-users. Time to listing was longer for cannabis users than non-users. The incidence of delisting was similar. There is an inconsistency between transplant centres regarding transplantation candidacy for cannabis users. While only 14% of Canadian centres had a policy in place and preferred candidates to abstain or decrease cannabis use before transplantation, a third of Canadian centres rejected cannabis users. Observational studies failed to demonstrate significant differences in patient survival between pre-transplantation cannabis users and non-users. However, self-reported mental health ratings were worse in post-transplantation cannabis users than in non-users and former users.

Conclusions

Current observational data do not support a link between cannabis use and poor patient survival post-transplantation. However, high-quality prospective studies are needed to better elucidate the impact of cannabis use on liver transplantation outcomes. Liver transplant candidacy should be evaluated through a multidisciplinary and comprehensive approach considering all relevant psychosocial factors.

Legislation and Policy Recommendations on Organ and Tissue Donation and Transplantation From an International Consensus Forum

There is a shared global commitment to improving baseline donation and transplantation performance metrics in a manner consistent with ethics and local cultural and social factors. The law is one tool that can help improve these metrics. Although legal systems vary across jurisdictions, our objective was to create expert, consensus guidance for law and policymakers on foundational issues underlying organ and tissue donation and transplantation (OTDT) systems around the world.

Methods

Using the nominal group technique, a group composed of legal academics, a transplant coordinator/clinician, and a patient partner identified topic areas and recommendations on foundational legal issues. The recommendations were informed by narrative literature reviews conducted by group members based on their areas of expertise, which yielded a range of academic articles, policy documents, and sources of law. Best practices were identified from relevant sources in each subtopic, which formed the basis of the recommendations contained herein.

Results

We reached consensus on 12 recommendations grouped into 5 subtopics: (i) legal definitions and legislative scope, (ii) consent requirements for donation' (iii) allocation of organs and tissue' (iv) operation of OTDT systems' and (v) travel for transplant and organ trafficking. We have differentiated between those foundational legal principles for which there is a firm basis of support with those requiring further consideration and resolution. Seven such areas of controversy are identified and discussed alongside relevant recommendations.

Conclusions

Our recommendations encompass some principles staunchly enshrined in the OTDT landscape (eg, the dead donor rule), whereas others reflect more recent developments in practice (eg, mandatory referral). Although some principles are widely accepted, there is not always consensus as to how they ought to be implemented. As the OTDT landscape continues to evolve, recommendations must be reconsidered for the law to keep pace with developments in knowledge, technology, and practice.

Substance use disorders in organ transplantation: perennial challenges and interprofessional opportunities

PURPOSE OF REVIEW

The current article examines recent publications regarding ongoing clinical and ethical challenges and opportunities related to substance use disorders (SUD) in solid organ transplantation (SOT) utilizing a lens of interprofessional clinical models and care delivery.

RECENT FINDINGS

Innovative interprofessional clinician skillsets and care models are increasingly emphasized in the SOT literature as the standard of care for common, complex psychosocial problems like substance use and SUD. Cannabinoids are common among candidates and recipients and present several unique quandaries to SOT teams. Opioid use disorder treatment can often be definitively treated with medications that SOT teams may find unfamiliar, controversial, or aversive. Arguably the quintessential example of SUD in SOT, early liver transplantation for patients with alcohol-related liver disease and short periods of sobriety has become increasingly common and accepted in recent years requiring liver teams to rapidly acquire significant interprofessional psychiatric awareness and expertise. The question of retransplantation in patients who have experienced recurrent SUD remains unsettled.

SUMMARY

Regardless of substances used or organs transplanted, interprofessional care continues to emerge as a foundational aspect of clinical care and research in SOT.

Rising Trend in Waitlisting for Alcoholic Hepatitis With More Favorable Outcomes Than Other High Model for End-stage Liver Disease in the Current Era

BACKGROUND

In the appropriate candidate, liver transplantation (LT) is a viable treatment for alcoholic hepatitis (AH). We compared the waitlisting trends and outcomes of AH patients in the context of others with high Model for End-stage Liver Disease (MELD) score.

METHODS

LT listings for AH between January 1, 2008, and June 12, 2020 were identified in the United Network for Organ Sharing database. Temporal trends in listings for AH were assessed. Covariate adjusted competing risks models evaluated waitlist mortality and LT rates between AH candidates and others with listing native MELD ≥30.

RESULTS

Between 2008 and 2019, waitlist additions for AH increased 6.5-fold. Waiting time for AH candidates was short (median 10 d). Delisting for clinical improvement was infrequent in AH, albeit higher than MELD ≥30 patients (3.3% versus 0.8%; P < 0.001). Among 99 centers with ≥1 AH listing, AH patients accounted for 0.2%-18.2% of all alcohol-related listings and 0.6%-25.0% of those with native listing MELD ≥30. Overall listing volume was larger at these 99 centers than the 40 with no AH listings (P < 0.001). AH candidates in 2014-2020 experienced improved waitlist survival (adjusted subhazard ratio, 0.67; 95% confidence interval, 0.52-0.86; P = 0.002) and higher transplant rates (adjusted subhazard ratio, 1.14; 95% confidence interval, 1.04-1.25; P = 0.006) versus other MELD ≥30 candidates.

CONCLUSIONS

There has been a rising trend in waitlisting patients with AH and high MELD score. Liver disease causes influence waitlist outcomes and those of AH candidates are more favorable. Further research and allocation adjustments may be needed to ensure equitable organ allocation, based on liver disease cause, for those on the LT waitlist.