A Systematic Review of Metoidioplasty and Radial Forearm Flap Phalloplasty in Female-to-male Transgender Genital Reconstruction: Is the “Ideal” Neophallus an Achievable Goal?

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 genital reconstruction was performed. Primary outcome measures were subsequently compared. A systematic review was planned in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyse guidelines. Grading of Recommendations Assessment, Development and Evaluation (GRADE) was utilized to evaluate the quality of evidence. RESULTS Using Population, Intervention, Comparison and Outcomes tool criteria, 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 evidence was low to very low for all included studies. In studies examining metoidioplasty, 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 underwent 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 micturition (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 percent reported successful penetration of partner during intercourse (6 NR), and 89% achieved standing micturition (6 NR). Compared with RFFP, metoidioplasty was significantly 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.