Sono-Urethrography in the Evaluation of Anterior Urethral Strictures

Abstract

During a 7-year period 123 paired urethrographic and sono-urethrographic studies were performed on 101 patients with 110 urethral strictures. In all but 3 cases the urethra was subsequently evaluated either cystoscopically or at open operation. Sono-urethrography readily identified urethral calculi, diverticula and false passages. It correctly identified the stricture and its site in every case. There was a significant difference between stricture length as measured by urethrography compared to that measured by sono-urethrography (p less than 0.003). However, if the strictures were grouped based on anatomical location, there was good correlation and no significant difference in the penile urethra (correlation coefficient = 0.94, p = 0.74) but poor correlation and the significant difference remained in the urethral bulb (correlation coefficient = 0.64, p less than 0.007). Similarly, when urethrographic and sono-urethrographic stricture lengths were compared with operative lengths, in the penile urethra the correlation coefficients were close (correlation coefficient = 0.91 versus 0.98) but in the urethral bulb the poor correlation persisted (correlation coefficient = 0.69 versus 0.89). Although sono-urethrography certainly identifies periurethral tissue, it was unreliable in predicting the depth of spongiofibrosis when compared with full depth biopsies in 36 patients with histopathological correlation. Finally, in 16 percent of the patients sono-urethrography correctly indicated a reconstructive procedure different from that originally suggested by conventional urethrography. Sono-urethrography is a dynamic 3-dimensional study that accurately identifies stricture site, number and caliber. Compared with conventional urethrography, it more accurately measures stricture length and diameter, and identifies periurethral tissue, making it a valuable adjunct in the evaluation of patients with suspected anterior urethral strictures.