Cannabis Abuse and Perioperative Complications Following Inpatient Spine Surgery in the United States

Ryan G. Chiu, BS; Saavan Patel, BS; Neha Siddiqui, MS; Ravi S. Nunna, MD; Ankit I. Mehta, MD, FAANS


Spine. 2021;46(11):734-743. 

In This Article

Abstract and Introduction


Study Design: Retrospective cohort analysis of a nationwide administrative database.

Objective: The aim of this study was to analyze the association between cannabis abuse and serious adverse events following elective spine surgery.

Summary of Background Data: Cannabis is the most popular illicit drug in the United States, and its use has been increasing in light of state efforts to decriminalize and legalize its use for both medical and recreational purposes. Its legal status has long precluded extensive research into its adverse effects, and to date, little research has been done on the sequelae of cannabis on surgical patients, particularly in spine surgery.

Methods: The 2012–2015 Nationwide Inpatient Sample was queried for all patients undergoing common elective spine surgery procedures. These patients were then grouped by the presence of concurrent diagnosis of cannabis use disorder and compared with respect to various peri- and postoperative complications, all-cause mortality, discharge disposition, length of stay, and hospitalization costs. Propensity score matching was utilized to control for potential baseline confounders.

Results: A total of 423,978 patients met inclusion/exclusion criteria, 2393 (0.56%) of whom had cannabis use disorder. After controlling for baseline characteristics and comorbid tobacco use, these patients similar inpatient mortality, but higher rates of perioperative thromboembolism (odds ratio [OR] 2.2; 95% confidence interval [CI] 1.2–4.0; P = 0.005), respiratory complications (OR 2.0; 95% CI 1.4–2.9; P < 0.001), neurologic complications such as stroke and anoxic brain injury (OR 2.9; 95% CI 1.2–7.5; P = 0.007), septicemia/sepsis (OR 1.5; 95% CI 1.0 to 2.5; P = 0.031), and nonroutine discharge (P < 0.001), as well as increased lengths of stay (7.1 vs. 5.2 days, P < 0.001) and hospitalization charges ($137,631.30 vs. $116,112.60, P < 0.001).

Conclusion: Cannabis abuse appears to be associated with increased perioperative morbidity among spine surgery patients. Physicians should ensure that a thorough preoperative drug use history is taken, and that affected patients be adequately informed of associated risks.

Level of Evidence: 3


Cannabis is one of the most popular psychoactive substances in the world, consumed by an estimated 183 million people, or 3.8% of the world's population.[1] In the United States, cannabis continues to stand as the most utilized recreational substance behind tobacco and alcohol, consumed by >15% of the population per year, in spite of the contentious surrounding legal atmosphere.[2] Since the turn of the century, the utilization and legal status of cannabis in the United States for medical and recreational purposes has undergone substantial reform, even in the face of a federal ban that has remained in place since the Controlled Substances Act of 1970.[3] The State of California's statewide legalization in 1996, in defiance of federal statute, sparked a subsequent wave of decriminalization and legalization efforts across the nation for the next two decades, and by the end of the 2010s, virtually all states had at least legalized cannabis for medically indicated use. With increasing legality and governmental tolerance came a decrease in the social stigmata surrounding cannabis' use, causing patients to more comfortably and readily report their use to their physicians, including surgeons before elective procedures.

Chronic cannabis use has been associated with various complications that may be of interest to spine surgeons. Despite the United States' having the highest rates of spine surgery in the world, no study has examined the effects of cannabis on patients undergoing these procedures.[4] The purported association of the substance with increased airway reactivity and other markers of hampered pulmonary function, as shown in several studies, may contribute to perioperative respiratory complications, and may be especially comorbid with surgical manipulation in the mid-cervical spine.[5–8] Another suggested association in the literature between cannabis use and myocardial infarction (MI) and stroke may further contribute to surgical patient morbidity,[9] and the vasoconstrictive effects on the peripheral vasculature suggested by some might potentially affect wound healing and bleeding risk, particularly with the extensive venous plexus involved in the paravertebral space.[6,10] The purpose of this study is to further evaluate the association between cannabis use and perioperative complications following elective spine surgeries.