Session: MP78: Trauma/Reconstruction/Diversion: Urethral Reconstruction (including Stricture & Diverticulum) II
MP78-07: The Prevalence of Concomitant Squamous Metaplasia in Bulbar Urethral Strictures and its Association with Reconstructive Delay and Urethral Rest by Suprapubic Urinary Diversion
Introduction: Squamous metaplasia (SM) of a normal urethral epithelium is considered to be the initial pathological change associated with a urethral stricture. SM proximal to a stricture is a severe problem that may affect the choice of urethroplasty technique and surgical outcome. A histological analysis was conducted to evaluate the prevalence of SM in bulbar urethral strictures and the association with delayed reconstruction and urethral rest. Methods: We reviewed the records of 169 male patients with bulbar urethral strictures who had undergone excision and primary anastomosis (EPA) between 2010 and 2020 by a single surgeon (AH). Those with prior urethroplasty and incomplete data were excluded from analysis. The proximal edges of formalin-fixed, paraffin-embedded urethral sections were sliced axially, and ImageJ measured the ratio of the urethral lumen in which SM was present on HE-stained slides by an experienced pathologist (MK). Reconstructive delay was calculated as the time between the initial stricture diagnosis and EPA. Urethral rest was accomplished by suprapubic tube placement and cessation of voiding at least three months before EPA. The success of EPA was defined as the absence of need for additional treatment. Results: SM was present in 88 patients (52.1%), and the median ratio of SM in the urethral lumen was 13.5%. The median reconstructive delay in patients with SM (40 months) was significantly longer than that in patients without SM (9 months, p<0.0001). Patients with SM were significantly more likely to have had no urethral rest (p < 0.0001) and undergo repeat transurethral treatments such as urethrotomy and dilation before EPA (p=0.0002). Multivariate logistic regression analysis showed that a longer reconstructive delay (for every month: odds ratio (OR) 1.01, 95% confidence interval (CI) 1.00–1.02, p = 0.004) and absence of urethral rest (OR 3.82, 95% CI 1.59–9.20, p = 0.002) were significant predictors of concomitant SM. There was no significant difference in the success rates between patients with SM (82 of 88, 93.1%) and those without SM (79 of 81, 97.5%, p=0.18). Conclusions: Persistent chronic high-pressure voiding due to reconstructive delay and absence of urethral rest are responsible for concomitant SM. SOURCE OF Funding: Nothing
