Partial Flap Loss in Gender Affirming Phalloplasty

Background: Flaps used in phalloplasty are larger than described for other indications, with a design that is tubularized up to two times. While the incidence of partial flap loss (PFL) is well described, current literature lacks granularity comparing donor sites and techniques with minimal discussion of etiology and management. The purpose of this study was to review our experience with PFL in phalloplasty. Methods: This was a retrospective cohort study of patients who underwent phalloplasty by a single surgeon at a single institution between 2016 and 2020. PFL was defined as any patient requiring sharp excision of necrotic tissue and reconstruction. Patient variables (demographics, body mass index, American Society of Anesthesiologists physical status classification, comorbidities), flap variables (donor site, design, dimensions, perforator number) and intraoperative variables (use of vasopressors, intraoperative fluid volume) were collected. Results: Of 76 phalloplasties, 6 patients suffered PFL (7.9%). 5/6 patients were radial forearm free flap tube-within-tube (TWT) and 1/5 patients were pedicled anterolateral thigh TWT. 4/6 cases involved the shaft only and were treated with excision ± Integra and full-thickness skin grafting. 2 cases of PFL involved the urethral extension requiring excision of the necrotic segment. Conclusion: PFL occurred in 7.9% of cases and was solely found in the TWT cohort. The majority of cases involved the shaft, sparing the urethral segment. Cases in the acute postoperative period appeared to be related to macrovascular venous congestion, while cases in the subacute period appeared to be due to microvascular arterial ischemia.