A Systematic Review of Metoidioplasty and Radial Forearm Flap Phalloplasty in Female-to-male Transgender Genital Reconstruction

Introduction: The complex anatomy and function of the native penis is difficult to surgically replicate. Metoidioplasty and radial forearm flap phalloplasty (RFFP) are the 2 most commonly utilized procedures for transgender neophallus construction. Methods: A MEDLINE search for metoidioplasty and RFFP in female-to-male geni- tal reconstruction was performed. Primary outcome measures were subsequently compared. A systematic review was planned in accordance with Preferred Report- ing Items for Systematic Reviews and Meta-Analyse guidelines. Grading of Recom- mendations Assessment, Development and Evaluation (GRADE) was utilized to evaluate the quality of evidence. Results: Using Population, Intervention, Comparison and Outcomes tool cri- teria, a total of 188 articles were identified; 7 articles related to metoidioplasty and 11 articles related to RFFP met inclusion criteria. The GRADE quality of ev- idence was low to very low for all included studies. In studies examining metoid- ioplasty, the average study size and length of follow-up were 54 patients and 4.6 years, respectively (1 study did not report [NR]). Eighty-eight percent under- went a single-stage reconstruction (0 NR), 87% reported an aesthetic neophallus (3 NR), and 100% reported erogenous sensation (2 NR). Fifty-one percent of patients reported successful intercourse (3 NR), and 89% of patients achieved standing mic- turition (3 NR). In studies examining RFFP, the average study size and follow-up were 60.4 patients and 6.23 years, respectively (6 NR). No patients underwent single-stage reconstructions (8 NR). Seventy percent of patients reported a satisfactorily aesthetic neophallus (4 NR), and 69% reported erogenous sensation (6 NR). Forty-three per- cent reported successful penetration of partner during intercourse (6 NR), and 89% achieved standing micturition (6 NR). Compared with RFFP, metoidioplasty was sig- nificantly more likely to be completed in a single stage (P < 0.0001), have an aesthetic result (P = 0.0002), maintain erogenous sensation (P < 0.0001), achieve standing micturition (P = 0.001), and have a lower overall complication rate (P = 0.02). Conclusions: Although the current literature suggests that metoidioplasty is more likely to yield an “ideal” neophallus compared with RFFP, any conclusion is severely limited by the low quality of available evidence.