To characterize the bulbospongiosus muscle (BSM) in patients with bulbar urethral strictures.

We studied 21 patients divided into 2 groups: Stricture Group (n=14; mean age=62.00 years) with bulbar stricture submitted to open urethroplasty; and Control Group (n=7; mean age=60. 14 years) with penile strictures (hypospadias cripples, penile cancer and/or penile infection) who were submitted to perineal urethrostomy. Samples of the BSM were dissected and histological sections were stained by histochemical and immunohistochemical techniques. Histomorphometric analyzes were performed on photomicrographs. Means were statistically compared using the unpaired Student t-test and the Mann-Whitney test (p<0.05).

The etiology of bulbar urethral stricture was idiopathic in 2 cases (14.29%), post-TURP in 6 (42.86%), post open radical prostatectomy in 5 (35.71%) and post open prostatectomy in 1 case (7.14%). The average length of the stricture was 2.08 cm. The only parameter analyzed with significant difference between the groups was the vessels (significant difference between the control group: 5.11±1.98% and stricture group: 3.57±1.32%, p=0.0460). The quantitative analysis of collagen (Control Group: 10.63±5.37% and Stricture Group: 10.83±4.55%, p=0.9296); diameter of BSM muscle fibers (Control Group: 41.71±14.63µm and Stricture Group: 40.11±8.59µm, p=0.76 and elastic system fibers (Control Group; 3.83±1.54% and Stricture Group: 5.43±2.90%, p=0.2601) showed no significant difference.

Histological analysis showed a significant decrease of the bulbospongiosus muscle vessels in urethral stricture, without changes in elastic fibers, collagen, nerves and muscle fiber diameter. These findings show that the bulbar urethral stricture causes minimal alterations in the structure of the BSM.

Urology. 2020 Jan 08 [Epub ahead of print]

Edilaine F Alves, Carla M Gallo, Waldemar S Costa, Francisco J Sampaio, Luciano A Favorito

Universidade do Estado do, Rio de Janeiro, Faculdade de Ciencias Medicas, Brazil., State University Rio de janerio, Rio de janeiro, Brazil. Electronic address: .