Postoperative complications following mastopexy and reduction mammaplasty in patients with cannabis use disorder: a propensity-matched cohort study.

Upreti N.; Chilappa R.; Tummala S.; Nagarkar P. · JPRAS open · 2026

**Background & Methods** This retrospective, propensity-matched cohort study used the TriNetX federated research network to compare postoperative complications between patients with and without cannabis use disorder (CUD) undergoing mastopexy or reduction mammaplasty. A total of 2,444 patients (1,222 per group) were matched 1:1 on age, sex, race, ethnicity, comorbidities, and procedure type, with CUD defined as documented diagnosis within 3 years before surgery. **Key Findings** • Patients with CUD demonstrated significantly higher rates of surgical site infection (3.8% vs. 2.0%; RR 1.84; P = 0.011) and seroma or hematoma formation (3.6% vs. 2.0%; RR 1.83; P = 0.014) within 90 days postoperatively compared to the control group. • CUD was associated with increased 30-day emergency department utilization (14.2% vs. 9.6%; RR 1.48; P < 0.001), suggesting heightened postoperative morbidity requiring urgent evaluation. • Wound dehiscence rates were not significantly different between groups (5.6% vs. 4.2%; RR 1.35; P = 0.092), indicating selective vulnerability to specific wound complication types rather than generalized wound healing impairment. **Dosage & Administration** Not reported. **Safety & Adverse Effects** The study documented postoperative complication rates rather than direct adverse effects of cannabis. Documented complications in the CUD cohort included surgical site infections, seroma/hematoma formation, and increased emergency department visits within 30 days postoperatively. Absolute risk differences were characterized as small despite statistical significance. **Evidence Quality** This study represents moderate-quality evidence with significant limitations. As a retrospective analysis without causal attribution established, confounding variables related to CUD (including potential concurrent substance use, medication adherence, postoperative self-care compliance, and socioeconomic factors) may have contributed to observed outcomes. The study excluded patients with cocaine or methamphetamine use but did not stratify by cannabis frequency, intensity, or timing relative to surgery. The use of administrative claims data may underestimate true CUD prevalence and complication rates. While propensity matching controlled for documented comorbidities, unmeasured confounding remains a concern. The findings support increased surveillance in CUD patients undergoing breast surgery but do not establish mechanistic causality.

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