Penile and Scrotal Skin Measurements to Predict Final Vaginal Depth With Penile Inversion Vaginoplasty

Abstract

AbstractIntroductionNo nomogram exists to predict maximum achievable neovaginal depth before penile inversion vaginoplasty (PIV) based on available penile & scrotal skin (SS). Maximal depth is important to patients and is determined by available skin and available anatomic space within the pelvis and varies with surgical technique.AimWe endeavored to create a nomogram to predict expected postoperative vaginal depth.MethodsRetrospective review of all patients undergoing primary PIV at a single institution from June 2017 to February 2020 (n = 60). Pre-op: Dorsal penile and midline scrotal skin length were measured. Intra-op: Tubularized scrotal skin length measured on a dilator. Immediate post-op: Final vaginal depth measured with a dilator.OutcomesThe amount of available penile and scrotal skin was not associated with vaginal depth. The only variable that did significantly increase depth was the use of penile + scrotal skin, as compared to penile skin alone. (P < .001)ResultsIn patients who underwent PIV-SS, the final vaginal depth (13.3 ± 1.9 cm) was 87% of pre-op measured penile skin length (15.3 ±- 3.0 cm). In patients who underwent PIV+SS, pre-op penile skin length was 11.1 ± 4.7±cm and pre-op midline scrotal length was 22.8 ± 2.6 cm. with a final post-op vaginal canal depth of 15.2 ± 1.3 cm. In 45/46 (98%) surgeries utilizing SS grafts, SS tube length exceeded the length necessary to achieve maximal vaginal depth, and required trimming and discard. Given that in most cases there was an excess of SS, final post-op depth equaled the maximal vaginal depth that could be surgically dissected, and was not limited by the amount of available skin.Clinical ImplicationsOur findings suggest that for most patients it should not be necessary to include additional tissue sources (eg, peritoneum) to create a vaginal canal during primary vaginoplasty.Strengths and LimitationsAny penile skin that was discarded due to poor quality (eg, tight phimosis, poor viability) was not measured and accounted for. This likely resulted in a slight overestimation of the contribution of the penile skin to the final vaginal depth, but did not change the overall finding that final depth was not limited by available skin.ConclusionSS grafts, when harvested and tubularized using optimized technique, supplied an excess of skin necessary to line a vaginal canal space of maximal achievable depth. We found that additional tissue sources can, instead, be reserved for future salvage surgery if it becomes necessary to augment depth.