History of Marijuana Use Does Not Affect Outcomes on the Liver Transplant Waitlist

Opioid use and risks in candidates and recipients of liver transplant

Opioid use is extremely prevalent among patients with cirrhosis and those who received liver transplant (LT), despite concerns regarding opioid-related risks in this population. While there are many theoretical risks of opioids in patients with hepatic dysfunction, there is limited evidence on the effect of opioid use on clinical outcomes in cirrhosis and patients before and after LT specifically. As a result, there is significant center-level variability in opioid-related practices and policies. The existing data-largely based on retrospective observational studies-do suggest that opioids are associated with increased health resource utilization pre-LT and post-LT and that they may precipitate HE in patients with cirrhosis and increase the risk of graft loss and death after LT. The strongest predictor of opioid use after LT is opioid use before transplant; thus, a focus on safe opioid use in the pretransplant and peritransplant periods is essential for minimizing opioid-related harms. We describe 3 strategies to guide LT providers including (1) improved characterization of pain, mental health symptoms, and opioid and polysubstance use; (2) minimization of opioid prescriptions for those at highest risk of adverse events; and (3) safe prescribing strategies for those who do use opioids and for the management of opioid use disorder. Ultimately, our goal is to improve the quality of life and transplant outcomes among patients with cirrhosis and those who received LT, particularly those living with concurrent pain, mental health, and substance use disorders.

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.

Marijuana use and post-transplant complications and non-compliance in liver transplant patients

BACKGROUND

Liver transplant (LT) is a lifesaving treatment for patients with end stage liver disease. Historically, institutions across the United States have deemed active marijuana use as an exclusion criterion for listing. This study aims to investigate LT outcomes in patients with history of marijuana use prior to LT.

METHODS

We performed a retrospective review of 111 patients who tested positive for marijuana on urine drug screen during initial LT evaluation between February 2016 and January 2021. 100 non-marijuana users who underwent LT were cross matched for control. Patient demographics, substance use history, and transplant decisions were recorded. Post-LT variables were also collected up to 1 year post surgery including postoperative infections, issues with non-compliance, and continued substance use. Chi-square analysis was used to assess the association between pre-transplant marijuana use and post-transplant complications. Logistics regression was implemented to measure associations amongst the entire cohort.

RESULTS

From 111 marijuana users, 32 (29%) received a transplant. There was no statistical difference in post-LT outcomes between marijuana and non-marijuana users, including incidence of cardiac, respiratory, renal, psychiatric, or neurological complications, as well as readmission rates post-surgery. There were no statistically significant associations between marijuana use with post-transplant bacterial or fungal infections, medication non-compliance, or continued substance use (all p>0.05). Marijuana use was associated with pre-LT tobacco use (p = 0.020).

CONCLUSIONS

Our data indicates that marijuana is not associated with increased risk of postoperative noncompliance, other organ complications, infections, or death. As a single factor, marijuana may not need to be a contraindication for LT.

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.

Cannabinoids and solid organ transplantation: Psychiatric perspectives and recommendations

Cannabinoid use in patients seeking solid organ transplantation (SOT) is an important and unsettled matter which all transplantation clinicians regularly encounter. It is also a multifaceted, interprofessional issue, difficult for any specialty alone to adequately address in a research article or during clinical care. Such uncertainty lends itself to bias for or against cannabinoid use accompanied by inconsistent policies and procedures. Scientific literature in SOT regarding cannabinoids often narrowly examines the issue and exists mostly in liver and kidney transplantation. Published recommendations from professional societies are mosaics of vagueness and specificity mirroring the ongoing dilemma. The cannabinoid information SOT clinicians need for clinical care may require data and perspectives from diverse medical literature which are rarely synthesized. SOT teams may not be adequately staffed or trained to address various neuropsychiatric cannabinoid effects and risks in patients. In this article, authors from US transplantation centers conduct a systematized review of the few existing studies regarding clinician perceptions, use rates, and clinical impact of cannabinoid use in SOT patients; collate representative professional society guidance on the topic; draw from diverse medical literature bases to detail facets of cannabinoid use in psychiatry and addiction pertinent to all transplantation clinicians; provide basic clinical and policy recommendations; and indicate areas of future study.

Cannabis use may reduce healthcare utilization and improve hospital outcomes in patients with cirrhosis

INTRODUCTION AND OBJECTIVES

Previous studies reveal conflicting data on the effect of cannabis use in patients with cirrhosis. This research evaluates the impact of cannabis on hepatic decompensation, health care utilization, and mortality in patients with cirrhosis.

MATERIAL AND METHODS

A retrospective analysis of the State Inpatient Database (SID) was performed evaluating patients from Colorado and Washington in 2011 to represent pre-cannabis legalization and 2015 to represent post-cannabis legalization. Multivariable analysis was performed to study the impact of cannabis on the rate of admissions with hepatic decompensations, healthcare utilization, and mortality in patients with cirrhosis.

RESULTS

Cannabis use was detected in 370 (2.1%) of 17,520 cirrhotics admitted in 2011 and in 1162 (5.3%) of 21,917 cirrhotics in 2015 (p-value <0.001). On multivariable analysis, cirrhotics utilizing cannabis after its legalization experienced a decreased rate of admissions related to hepatorenal syndrome (Odds Ratio (OR): 0.51; 95% Confidence Interval (CI): 0.34-0.78) and ascites (OR: 0.73; 95% CI: 0.63-0.84). Cirrhotics with an etiology of disease other than alcohol and hepatitis C had a higher risk of admission for hepatic encephalopathy if they utilized cannabis [OR: 1.57; 95% CI: 1.16-2.13]. Decreased length of stay (-1.15 days; 95% CI: -1.62, -0.68), total charges (-$15,852; 95% CI: -$21,009, -$10,694), and inpatient mortality (OR: 0.68; 95% CI: 0.51-0.91) were also observed in cirrhotics utilizing cannabis after legalization compared to cirrhotics not utilizing cannabis or utilizing cannabis prior to legalization.

CONCLUSION

Cannabis use in patients with cirrhosis resulted in mixed outcomes regarding hospital admissions with hepatic decompensation. A trend towards decreased hospital utilization and mortality was noted in cannabis users after legalization. These observations need to be confirmed with a longitudinal randomized study.

Cannabinoid Use Among Liver Transplant Recipients

The effect of cannabinoids on liver transplant outcomes is an area of active research. We aimed to investigate marijuana (MJ) and cannabidiol (CBD) use among liver transplant recipients at the University of Colorado Hospital (UCH), specifically prevalence, habits, and predictors of use. Liver transplant recipients followed at UCH with valid email addresses were sent an informed consent postcard and survey invitation. This exploratory survey was conducted using REDCap. IBM SPSS Statistics software was used for statistical analysis. Of 1227 recipients who were sent surveys, 538 people responded. On average, respondents were 59 years old, with 63.7% male and 81.7% White. Hepatitis C virus (HCV; 30.4%) and alcohol use (17.7%) were the most common etiologies of liver disease. Among respondents, 23.8% reported current MJ use. Methods of use included smoking (72.4%), ingestion (55.3%), and vaporization (31.7%). Top reasons for MJ use were recreation (56.5%), anxiety (54.8%), and pain (53.2%). Among respondents, 21.0% currently used CBD, usually in the form of creams or lotions (58.9%) and to relieve pain (84.9%) and anxiety (31.1%). In multivariable analysis, age (odds ratio [OR], 0.941; 95% confidence interval [CI], 0.923-0.959; P < 0.001), diabetes mellitus (OR, 0.357; 95% CI, 0.171-0.746; P = 0.01), HCV cirrhosis (OR, 3.949; 95% CI, 2.281-6.835; P < 0.001), alcohol-related cirrhosis (OR, 2.101; 95% CI, 1.202-3.671; P = 0.01), and current tobacco use (OR, 2.918; 95% CI, 1.065-7.990; P = 0.04) were significant predictors of MJ use. Our study shows that cannabinoid use after liver transplant is common. MJ use is associated with decreasing age, alcohol-related and HCV cirrhosis, and tobacco use. Anxiety, pain, and recreation were top reasons for its use. Transplant teams should address reasons why their patients use MJ and CBD and develop programs to mitigate anxiety and pain after transplant. Further studies are needed to examine effects of cannabinoids on liver transplant outcomes.

Chronic marijuana usage by human pancreas donors is associated with impaired islet function

We investigated the effect of chronic marijuana use, defined as 4 times weekly for more than 3 years, on human pancreatic islets. Pancreata from deceased donors who chronically used marijuana were compared to those from age, sex and ethnicity matched non-users. The islets from marijuana-users displayed reduced insulin secretion as compared to islets from non-users upon stimulation with high glucose (AUC, 3.41 ± 0.62 versus 5.14 ±0.47, p<0.05) and high glucose plus KCl (AUC, 4.48 ± 0.41 versus 7.69 ± 0.58, p<0.001). When human islets from chronic marijuana-users were transplanted into diabetic mice, the mean reversal rate of diabetes was 35% versus 77% in animals receiving islets from non-users (p<0.01). Immunofluorescent staining for cannabinoid receptor type 1 (CB1R) was shown to be colocalized with insulin and enhanced significantly in beta cells from marijuana-users vs. non-users (CB1R intensity/islet area, 14.95 ± 2.71 vs. 3.23 ± 0.87, p<0.001). In contrast, CB1R expression was not co-localized with glucagon or somatostatin. Furthermore, isolated islets from chronic marijuana-users appeared hypertrophic. In conclusion, excessive marijuana use affects islet endocrine phenotype and function in vitro and in vivo. Given the increasing use of marijuana, our results underline the importance of including lifestyle when evaluating human islets for transplantation or research.

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

Alcohol and cannabis use as a contraindication to organ transplantation is a controversial issue. Until recently, patients in Canada with alcohol-associated liver disease were required to demonstrate abstinence for 6 mo to receive a liver transplant. There is no equivalent rule that is applied consistently for cannabis use. There is some evidence that alcohol and cannabis use disorder pretransplant could be associated with worse outcomes posttransplantation. However, early liver transplantation for patients with alcohol-associated liver disease in France and in the United States has led to challenges of the 6-mo abstinence rule in Canada in the media. It has also resulted in several legal challenges arguing that the rule violates human rights laws regarding discrimination in the provision of medical services and that the rule is also unconstitutional (this challenge is still before the court). Recent legalization of cannabis use for adults in Canada has led to questions about the appropriateness of limiting transplant access based on cannabis use. The ethics committee of the Canadian Society of Transplantation was asked to provide an ethical analysis of cannabis and alcohol abstinence policies. Our conclusions were as follows: neither cannabis use nor the 6-mo abstinence rule for alcohol use should be an absolute contraindication to transplantation, and transplant could be offered to selected patients, further research should be conducted to ensure evidence-based policies; and the transplant community has a duty not to perpetuate stigma associated with alcohol and cannabis use disorders.

The impact of marijuana use on liver transplant recipients: A 900 patient single center experience

INTRODUCTION

Increased societal prevalence of marijuana continues to challenge liver transplant (LT) programs. This study aimed to examine the potential effects of marijuana use on outcomes.

METHODS

This retrospective study included recipients who underwent LT between 1/2012 and 6/2018. According to pre-LT marijuana use, patients were classified into recent (≤6 months of LT), former (chronic use but not ≤6 months), or non-users. Additionally, the impact of post-LT marijuana use on survival was assessed.

RESULTS

Of 926 eligible patients, 184 were pre-LT marijuana users (42 recent; 142 former) (median follow-up: 30.3 months). Pre-users were more likely to be male, White, and have histories of tobacco, alcohol, and illicit drug use. Additionally, recent users were of higher acuity, with higher MELD and requiring ICU admission. Patient survival at 1-year was 89% in non-users, 94% (HR: 0.494, 95% CI: 0.239-1.022 vs. non-users) in former users, and 83% (HR: 1.516, 95% CI: 0.701-3.282) in recent users. Post-operative complications in pre-LT users and the survival analysis for post-LT marijuana users vs. non-users did not show significance.

CONCLUSIONS

Our results demonstrated that marijuana use did not have an adverse impact on post-LT outcomes; however, further studies utilizing larger cohorts are warranted.

Heart transplantation candidacy

PURPOSE OF REVIEW

Timely referral of eligible candidates for consideration of advanced therapies, such as a heart transplantation or mechanical circulatory support is essential. The characteristics of heart transplantation candidates have changed significantly over the years, leading to a more complex evaluation process. The present review summarizes recent advances in the evaluation process for heart transplantation eligibility.

RECENT FINDINGS

The heart transplantation allocation policy was recently reviewed in the USA in an effort to reduce waitlist mortality and to ensure fair geographic allocation of organs to the sickest patients. Moreover, patients with chronic infectious diseases, as well as malignancies, are being currently considered acceptable candidates for transplantation. Listing practices for heart transplantation vary between programmes, with a greater willingness to consider high-risk candidates at higher-volume centres.

SUMMARY

The ultimate decision to place high-risk candidates on the heart transplantation waitlist should be based on a combination of quantitative and qualitative data analysis informed by clinical judgement, and the chronic shortage of organ donors makes this process an important ethical concern for any society. Future guidelines should discuss approaches to achieve fair organ allocation while preserving improved outcomes after transplantation.

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

BACKGROUND

When last assessed in 2013, all Canadian liver transplant programs required 6 months of abstinence from alcohol. New studies have questioned the validity of this policy. Moreover, with recreational cannabis now legal in Canada, more transplant candidates may use cannabis. Given these changes, our objective was to obtain an understanding of current Canadian practices regarding liver transplantation and candidates with addiction or alcohol, tobacco, cannabis, or opiate use.

METHODS

Electronic surveys were distributed to the medical directors of all seven adult liver transplant programs in Canada. Questions were based on either a Likert-scale ranking or free response. The complete data set was aggregated to provide a national perspective on this topic and ensure each individual program remained anonymous.

RESULTS

All seven programs responded to the survey. Of these programs, 43% always require 6-month abstinence from alcohol, 29% usually require it, and 14% sometimes require it. Formal alcohol rehabilitation is mandatory in two programs. The majority (57%) of programs never or rarely consider transplant for patients with acute alcoholic hepatitis; 29% require smoking cessation before consideration for transplant; and 71% felt that cannabis use is rarely or never a contraindication to liver transplantation.

CONCLUSIONS

Significantly more Canadian programs now perform liver transplant for patients who have less than 6 months abstinence from alcohol, and alcoholic hepatitis is no longer an absolute contraindication in Canada. Policies on smoking and opiates are quite variable. Further study and discussion are critical for development of national policies to obtain equitable access to liver transplant for all.

A Review of the Prevalence of Illicit Substance Use in Solid-Organ Transplant Candidates and the Effects of Illicit Substance Use on Solid-Organ Transplant Treatment Outcomes

Solid-organ transplantation is one of the significant advances in the medical field that have improved the quality of life and survival rates of numerous patients with end-organ dysfunction. Substance use is a common condition of individuals who are in need of solid-organ transplantation. The implications of substance use on solid-organ transplants are gaining increasing attention over the past decade. The current review seeks to explore the prevalence rate of illicit substance use among those who receive solid-organ transplantation (pre and post-transplant) and whether illicit substance use before solid-organ transplantation affects the outcome of solid-organ transplants. We searched the Medline database for all the articles available in English on the prevalence of substance use in the context of solid-organ transplant and the effect on outcome measures. We found 21 relevant articles. It appears that substance use is fairly common among solid-organ transplant candidates, with cannabis being the most common substance of abuse. A heterogeneous sample precludes the drawing of a clear-cut conclusion. But it appears that substance use may affect various outcomes of solid-organ transplants. The existing literature may not be sufficient to adequately assess the risk but limited evidence indicates that illicit substance use, particularly cannabis use, may not affect the overall survival following a solid-organ transplant.

Marijuana Consumption in Liver Transplant Recipients

Marijuana is legalized for either medical or recreational use in over half of the states in the United States and in Canada, but many transplant centers will not list patients who are using marijuana. However, the effect of marijuana on transplant outcomes remains unclear. Thus, we performed a retrospective analysis of all adult (≥18 years old) liver transplant patients treated at our center between 2007 and 2017. Patients were grouped according to their marijuana use and tobacco smoking status. We also evaluated tobacco smoking status for the comparative evaluation. Posttransplant morbidity, mortality, and graft survival were evaluated. In total, 316 patients were included: 171 (54%) patients were tobacco smokers (70 current; 101 former), 81 (26%) patients were marijuana smokers (13 current; 68 former), and 64 (20#x0025;) patients were both marijuana and tobacco smokers. A total of 136 (43%) reported never smoking marijuana or tobacco. After adjustment, current tobacco users were over 3 times as likely to die within 5 years compared with never users (hazard ratio [HR], 3.25; 95% confidence interval [CI], 1.63-6.46; P < 0.001), but no difference was seen between current/former and never marijuana users (HR, 0.52; 95% CI, 0.26-1.04; P = 0.06). No significant differences in inpatient respiratory complications, reintubation, or >24-hour intubation was seen. Overall, pretransplant marijuana use, past or current, does not appear to impact liver transplant outcomes, though tobacco smoking remains detrimental.

Marijuana use in transplantation: A call for clarity

Transplant centers have varying policies for marijuana (MJ) use in donors, transplant candidates, and recipients. Rationales for these differences range from concerns for fungal complications, impaired adherence, and drug interactions. This paper reviews the current status of MJ policies and practices in transplant centers and results of a survey sent to the American Society of Transplantation (AST) membership by the Executive Committee of the AST Infectious Diseases Community of Practice.The purpose of the survey was to compare policies and concerns of MJ use to actual observed complications. Of the 3321 surveys sent, 225 members (8%) responded. Transplant centers varied in their approval processes, differing even in organ types within the same institutions. Furthermore, there was discordance among transplant centers in their perceived risks of marijuana use as opposed to complications actually observed. An increasing number of states continue to legalize medical and recreational MJ resulting in widespread availability. Further research is needed to assess the validity of concerns for complications of MJ use in potential donors and recipients. Ultimately, standardized guidelines should be established based on studies and evidence-based criteria to assist transplant programs in their policies around the use of cannabis in their donors and recipients.

Specific issues concerning the management of patients on the waiting list and after liver transplantation

The present document is a second contribution collecting the recommendations of an expert panel of transplant hepatologists appointed by the Italian Association for the Study of the Liver (AISF) concerning the management of certain aspects of liver transplantation, including: the issue of prompt referral; the management of difficult candidates; malnutrition; living related liver transplants; hepatocellular carcinoma; and the role of direct acting antiviral agents before and after transplantation. The statements on each topic were approved by participants at the AISF Transplant Hepatology Expert Meeting organized by the Permanent Liver Transplant Commission in Mondello on 12-13 May 2017. They are graded according to the GRADE grading system.