102. Post-void Urethral Residual Volume and Lower Urinary Tract Symptoms Improve up to One Year Post-phalloplasty: A Prospective Cohort Study

Abstract

PURPOSE: Gender-affirming surgeries have been increasing considerably over the past decade, yet few studies report the functional outcomes after these surgeries. There were virtually no specific validated tools that assess the urinary outcomes following phalloplasty and flap-based neo-urethra reconstruction in transgender male patients. Patient outcome questionnaires adopted in cis-male urology have limitations in patients with flap-based neo-urethras. We therefore initially developed a Post-Phalloplasty Urinary Function Test (PP UFT) to better assess the lower urinary tract symptoms (LUTS) in this patient population following urethral lengthening surgery and found that many patients do suffer from LUTS. Post-void dribbling due to post-void urethral volume (PVUR) was responsible for most of the patient dissatisfaction and poor quality of life. In this study, we prospectively investigated the time course of urinary dysfunction using PP UFT and PVUR measurements in transmen during the first 12 months following urethral lengthening. METHODS: A pilot study of 15 adult trans-men who had undergone phalloplasty with urethral lengthening surgery was done to validate the PP UFT scale. We then conducted a prospective cohort study of nine transmen who underwent phalloplasty with urethral lengthening surgery between 2019 and 2021 at a single institution. Patients were followed at 2, 4, 6, and 12-month intervals after their stage-two phalloplasty procedure. To assess lower urinary tract symptoms, patients were asked to complete the PP UFT, and PVUR was recorded at each visit by measuring residual urine after voiding via “milking technique”. Significance was assessed using Wilcoxon Signed-Rank tests with a cutoff set at 0.05. RESULTS: Nine patients were included in the study. Average PP UFT score improved from 7.9 out of 40 points at two months (IQR 6,8) to 4.6 points by six months (p<0.05; IQR 2,6) with a net improvement of 4 points by 12 months. Average PVUR improved from 7.6 mL at two months (IQR 4.5-12.5) to 4.4mL at six months (p<0.05; IQR 3.3-4.5), with a net improvement of 4.5mL by 12 months. Two of eight patients who reported incontinence at two months after surgery claimed to no longer suffer from incontinence at six months. CONCLUSION: Combination of PP UFT and PVUR measurements up to one-year following second- stage phalloplasty offer promise for quantifying urinary function and quality of life, although larger studies are needed to validate these instruments. Future directions include multi-institutional prospective studies with greater than one-year follow-up and the addition of PVUR and PPUFT questionnaires with cross-comparison to CT imaging protocols.