Factors influencing intraoperative conversion from double- to single-incision mastectomy with free nipple grafts in 352 transgender and non-binary patients.

BACKGROUND

Double-incision mastectomy (DIM) with free nipple grafts (FNG) is a common technique employed in gender-affirming mastectomy (GAM), but is associated with a high scar burden. Intraoperatively, the surgeon may opt for a single-incision mastectomy (SIM) along the inframammary folds (IMF) to optimize aesthetic outcomes. This study sought to identify factors predictive of intraoperative conversion.

METHODS

From February 2018 to November 2022, TGNB patients who underwent GAM at a single institution were retrospectively reviewed. Data regarding patient characteristics, perioperative details, postoperative complications, and aesthetic satisfaction were collected.

RESULTS

A total of 352 patients were identified. Median age and body mass index (BMI) were 25.0 years (IQR: 9.0) and 28.5 kg/m (IQR: 8.5), respectively. Most patients received IMF incisions (n = 331, 94.0%); of whom, 66 (19.9%) underwent intraoperative conversion from DIM to SIM with FNG. Larger breast cup-size (p < 0.001) and a greater degree of ptosis (p = 0.002) preoperatively were significantly associated with intraoperative conversion to SIM. There was no significant association between intraoperative conversion and the ratio of intermammary distance to the width of the chest wall (p = 0.086). Overall complication rates were significantly higher among patients with diabetes mellitus (p = 0.015) and a greater degree of ptosis (p = 0.018). 77.8% (n = 274) of patients were satisfied with their aesthetic outcome. NPWT usage was associated with higher rates of aesthetic satisfaction (83.6% vs. 77.8%; p = 0.005).

CONCLUSION

Patients with larger breast cup size and greater degree of ptosis should be counseled preoperatively that they may be at a higher risk of conversion to a singular incision.