Impact of Obesity on Surgical Complications in Gender-Affirming Mastectomy: A Systematic Review and Meta-analysis

Body mass index (BMI) is sometimes used to determine surgical eligibility for gender-affirming mastectomy (GAM) but there is insufficient data informing these criteria. Given the limitations of single-institution studies, which lack the ability to generalize the potential impact of BMI on GAM complications across various surgical practices, a systematic review is needed.

A systematic review and meta-analysis was performed for all studies that evaluated the relationship between BMI and surgical outcomes after GAM. Our institution's GAM cohort (n = 457) was also included. Obesity was defined as BMI ≥ 30 kg/m 2 . The random-effects DerSimonian-Laird method was used to synthesize results across studies.

Of 605 studies screened, 10 met the inclusion criteria. There were a total of 1195 patients, of whom 441 (37%) were obese and 754 (63%) were nonobese. There were significantly higher odds of nipple-areola complex [odds ratio (OR) = 4.13, P = 0.04] and wound complications (OR = 4.27, P = 0.03) in patients with obesity compared to those without obesity. There were no significant differences in hematoma (OR = 1.16, P = 0.62), seroma (OR = 2.49, P = 0.14), or infection (OR = 1.63, P = 0.24).

While some GAM complications were more common in patients with obesity, serious complications like hematoma and infection were as likely to occur among obese and nonobese patients. Patients with higher BMIs should be counseled about their increased risk for these complications. However, BMI cutoffs alone should not determine surgical eligibility, as these findings provide more generalizable evidence confirming the low morbidity associated with GAM.