Assessment of Canadian policies regarding liver transplant candidacy of people who use alcohol, tobacco, cannabis, and opiates

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.

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.

Exception points for liver transplantation: A Canadian review

Background

Exception points for liver transplant (LT) allocation are used to account for mortality risk not reflected by scoring systems such as the Model for End-Stage Liver Disease with sodium (MELD-Na). Currently, there is no formal policy regarding exception points in Canada, and differences across the country are not well understood. As such, a review of the criteria and exception points granted throughout the country for LT was conducted.

Methods

Seven LT centres in five provinces were surveyed (Vancouver, Edmonton, London, Toronto, Montréal, Halifax) regarding the indications and criteria for exception points granted, the number of points granted, how points would be accrued, and the maximum points granted.

Results

Programs in British Columbia and Nova Scotia grant variable exception points based on the median MELD-Na score with modifications; Alberta, Ontario, and Quebec grant exception points using specific values based on the indication. Overall, there was significant heterogeneity regarding exception points granted nationally with agreement only for awarding exception points for hepatopulmonary syndrome and polycystic liver disease. The second most common agreed-upon indications for exception points were portopulmonary hypertension and recurrent cholangitis offered by four provinces. Quebec had the most formal criteria for non-cirrhosis-based conditions.

Conclusions

There is substantial variance across the country regarding the indications for granting exception points as well as the number of points granted. Future work on developing a national consensus will be important for the development of equity in LT across Canada.

Liver transplantation in alcohol-associated liver disease: ensuring equity through new processes

Worsened by the COVID-19 pandemic, alcohol use is one of the leading causes of preventable death in the US, in large part due to alcohol-associated liver disease. Throughout history, liver transplantation for this population has been controversial, and many policies and regulations have existed to limit access to lifesaving transplant for patients who use alcohol. In recent years, the rates of liver transplantation for patients with alcohol-associated liver disease have increased dramatically; however, disparities persist. For instance, many criteria used in evaluation for transplant listing, such as social support and prior knowledge of the harms of alcohol use, are not evidence based and may selectively disadvantage patients with alcohol use disorder. In addition, few transplant providers have adequate training in the treatment of alcohol use disorder, and few transplant centers offer specialized addiction treatment. Finally, current approaches to liver transplantation would benefit from adopting principles of harm reduction, which have demonstrated efficacy in the realm of addiction medicine for years. As we look toward the future, we must emphasize the use of evidence-based measures in selecting patients for listing, ensure access to high-quality addiction care for all patients pretransplant and posttransplant, and adopt harm reduction beliefs to better address relapse when it inevitably occurs. We believe that only by addressing each of these issues will we be able to ensure a more equitable distribution of resources in liver transplantation for all patients.