Vol.:(0123456789) 1 3 Surgical Endoscopy https://doi.org/10.1007/s00464-020-07497-5 Marijuana use does not afect the outcomes of bariatric surgery Nicole Shockcor 1  · Sakib Mohammad Adnan 2  · Ariel Siegel 2  · Eric Wise 2  · Syed Nabeel Zafar 2  · Mark Kligman 2 Received: 7 August 2019 / Accepted: 2 March 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract Background The decriminalization of marijuana and legalization of derived products requires investigation of their efect on healthcare-related outcomes. Unfortunately, little data are available on the impact of marijuana use on surgical outcomes. We aimed to determine the efect of marijuana use on 30-day complications and 1-year weight loss following laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG). Methods At a large academic center, 1176 consecutive patients undergoing primary bariatric surgery from 2012 to 2017 were identifed and separated into cohorts according to marijuana use. The only exclusions were 19 patients lost to follow-up. Propensity score matching, using logistic regression according to preoperative age, gender, BMI, and comorbid conditions, yielded 73 patient pairs for the control and study arms. All patients were followed two years postoperatively. Results Excess BMI lost did not difer between marijuana users and controls at 3 weeks (23.0% vs 18.9%, p = 0.095), 3 months (42.0% vs 38.1%, p = 0.416), 6 months (60.6% vs 63.1%, p = 0.631), 1 year (78.2% vs 77.3%, p = 0.789), or 2 years (89.1% vs 74.5%, p = 0.604). No diferences in the rate of major 30-day postoperative complications, including readmission, infection, thromboembolic events, bleeding events and reoperation rates, were found between groups. Follow-up rate at two years was lower in marijuana users (12.3% vs 27.4%, p = 0.023). Conclusion This study suggests marijuana use has no impact on 30-day complications or weight loss following bariatric surgery, and should not be a contraindication to bariatric surgery. Keywords Bariatric surgery · Outcomes · Cannabis · Marijuana · Obesity The decriminalization of marijuana, the most commonly used non-prescription drug in the USA, has focused atten- tion on its impact on healthcare-related outcomes [1]. While the psychosocial impact of marijuana use has been exten- sively explored, research on the physiological efects of marijuana on surgical outcomes is in its nascent stage [2–4]. The bariatric population has a disproportionate burden of medical comorbidities and a predisposition to pre- and post- operative polysubstance abuse [5]. Specifcally, marijuana users have been described as having greater perioperative opioid requirements and disordered eating patterns after bariatric surgery, though without any deleterious impact on 90-day weight loss [6, 7]. Given these potential side efects of marijuana use in the metabolically compromised bariatric surgery population and the association with high-risk behav- iors that may negatively impact postoperative outcomes, weight loss surgery programs have been tentatively advised to consider marijuana use a contraindication to bariatric sur- gery [8, 9]. However, the paucity of the literature on the impact of marijuana use on long-term outcomes following bariatric surgery makes this recommendation tenuous. The aim of this study is to present a single institution’s experience with bariatric surgery in marijuana users (MU) versus a non-user control group (CON), comparing weight loss and 30-day complications. and Other Interventional Techniques * Nicole Shockcor nshockcor@som.umaryland.edu 1 University of Maryland School of Medicine, 29 S. Greene St., Ste 105, Baltimore, MD 21201, USA 2 University of Maryland School of Medicine, Baltimore, MD, USA