A Systematic Review Examining Metoidioplasty and Radial Forearm Flap Phalloplasty in Female-to-Male Genital Reconstruction: Is the Ideal Neophallus an Achievable Goal?

Introduction: The ideal neophallus in female-to-male genital reconstruction is achieved in a single-stage, is aesthetic, has tactile and erogenous sensation, achieves sexual intercourse and standing micturition with a functional neourethra, and has minimal complications and donor site morbidity. Metoidioplasty and radial forearm flap phalloplasty (RFFP) are the most common procedures for neophallus construction despite no comparative studies of the procedures.

Methods: A MEDLINE search for metoidioplasty and RFFP in female-to-male genital reconstruction was performed with outcomes compared.

Results: A total of 188 articles were identified; 7 articles related to metoidioplasty and 11 articles related to RFFP met inclusion criteria.

In studies examining metoidioplasty, average study size and follow-up was 50.9 patients and 4.6 years (2 studies did not report [NR] these metrics). 88% had a single-stage reconstruction (1 NR), 87% reported a satisfactorily aesthetic neophallus (4 NR), 100% reported erogenous sensation (3 NR), no studies reported tactile sensation (7 NR), 51% of patients were able to achieve sexual intercourse (4 NR), 74% had a functional neourethra without fistula or stricture (0 NR), 75% achieved standing micturition (3 NR), overall complication rate was 38% (0 NR), and donor site morbidity was 6% (0 NR).

In RFFP, study size and follow-up was 60.4 patients and 6.23 years (6 NR). No patients had single-stage reconstruction (8 NR), 70% reported a satisfactorily aesthetic neophallus (4 NR), 69% reported erogenous sensation (6 NR), 77% reported tactile sensation (9 NR), 43% were able to achieve sexual intercourse (6 NR), 50% had a functional neourethra (4 NR), 75% achieved standing micturition (6 NR), complication rate was 67% (3 NR), and donor site morbidity was 11% (3 NR).

Comparing the groups, sample size (p=0.7722) and follow up (p=0.1798) were similar. Compared to 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) and have lower neourethral fistula/stricture (p<0.0001) and overall complication rates (p<0.0001). Outcomes for standing micturition (p=1.000), donor site morbidity (p=0.11), and ability for sexual intercourse (p=0.1061) were similar; tactile sensation could not be compared.

Conclusions: Current literature suggests metoidioplasty may more successfully achieve an ideal neophallus than RFFP. High-quality studies with emphasis on patient-reported outcome measures are required to more critically evaluate female-to-male genital reconstruction.