Abstract
Background There is an increasing prevalence of marijuana use in the general population yet
clinical studies on marijuana's effect on surgical outcomes remain limited. Marijuana's
effect on wound healing, venous thromboembolism (VTE) due to endothelial inflammation,
and bleeding due to inhibited platelet function have been cited based on animal models
but have not been evaluated clinically in patients undergoing microsurgical reconstruction.
Methods Retrospective chart review was performed on all patients who underwent abdominal-based
free flap breast reconstruction in a single institute from August 2018 to December
2022. Patient self-reported marijuana use, demographics, total narcotic use during
hospitalization converted to oral morphine milligram equivalent (MME), and 90-day
complications were collected and compared.
Results A total of 162 patients were included and 13 patients (8.5%) had reported marijuana
use on presurgical history. Marijuana users are more likely to be younger and report
concurrent nicotine smoking. Marijuana users were also at a significantly elevated
risk of developing symptomatic VTE (15 vs. 1%; odds ratio (OR) 13.4 [95% confidence
interval (CI) 1.71–104.2]; p = 0.01) and marijuana use remained a significant risk factor with multivariate analysis.
On postoperative 90-day complications, there was no increased risk of flap loss, reoperation,
postoperative transfusion, or hematoma associated with marijuana use, and no significantly
increased risk for overall donor or recipient site complications. Marijuana users
required significantly more narcotics for pain control during hospitalization (100 ± 77
vs. 49 ± 45 MME; p = 0.0003), although they had similar lengths of stay, achievement of mobilization
on post operative day (POD)1, and maximal pain scores.
Conclusion Marijuana use increases the risks of postoperative VTE and increased postoperative
narcotic requirements in patients who underwent abdominal-based free flap breast reconstruction.
Future prospective cohort study is required to further understand marijuana-associated
risks in microsurgical procedures.
Keywords
marijuana - cannabis - microsurgical breast reconstruction
