High frequency of concomitant squamous metaplasia in bulbar urethral stricture and its association with reconstructive delay and urethral rest.

ABSTRACT

PURPOSE: To determine the prevalence of concomitant squamous metaplasia (SM), the initial histological change from normal urethra to urethral stricture, in bulbar urethral strictures and to investigate the associated clinical factors. METHODS: A retrospective review was conducted on 165 male patients with bulbar urethral strictures who underwent excision and primary anastomosis (EPA) between 2010 and 2020, for whom complete clinical data and excised urethral specimens were available. An experienced pathologist histologically evaluated concomitant SM in paraffin sections of the proximal end of the excised urethra blinded to the clinical data. Disease duration was calculated as the period from the initial diagnosis of urethral stricture to the date of EPA. The association between concomitant SM and clinical background was investigated. RESULTS: SM was identified in 86 (52.1%) patients. The median disease duration in patients with SM (38 months) was significantly longer than that in patients without SM (9 months, p < 0.0001). In multivariate analysis, the longer disease duration, non-traumatic stricture etiology, and failure to maintain urethral rest with urinary diversion via a suprapubic tube for more than 90 days were independent factors predicting concomitant SM. No significant difference was observed in success rates of EPA between patients with SM (93.2%) and those without SM (97.5%, p = 0.18). CONCLUSIONS: Reconstructive urologists need to be aware that concomitant SM is frequent in patients with bulbar urethral stricture, especially in those with long disease duration and those who were voiding volitionally during the period of urethral rest.