Comparison of sonoelastography with sonourethrography and retrograde urethrography in the evaluation of male anterior urethral strictures.

Abstract

Retrograde urethrography (RUG) is the most common and preferred imaging modality for imaging of the anterior urethral strictures despite its well-known limitations and disadvantages. Sonourethrography (SUG) was introduced in 1988 to overcome the limitations of RUG and to provide more accurate results. As proper selection of imaging modality is very important for planning the treatment, various advances in this area are required. One of the major factors for recurrence of stricture disease is spongiofibrosis. Sonoelastography (SE) is a newer technique, tried in various other pathologies. In this study, we have used this technique for the first time to assess its efficacy in the evaluation of anterior urethral stricture disease by comparison with RUG and SUG. Between August 2014 and May 2015, 77 patients with clinical features of anterior urethral stricture disease were included in the study and evaluated by RUG followed by SUG and SE for stricture location, length, depth of spongiofibrosis and periurethral pathologies. The results were then correlated with operative and histopathological findings. Overall diagnostic accuracy of SE, SUG, and RGU for the estimation of stricture location, and length were estimated 92.68% vs. 91.54%, 79% vs. 78.87% and 80.48% vs. 43.66%, respectively, while for depth of spongiofibrosis SE, and SUG had accuracy rates of 87.3%, 48%, respectively. The mean length measured on SE was nearest to the mean intra-operative stricture length (21.34+11.8 mm). SE findings significantly correlated with the colour of bladder mucosa on cystoscopic examination (p=0.003) whereas the association was non-significant (p=0.127) for difficulty in incision. While a nonsignificant correlation existed between SUG findings related both to the colour of the bladder mucosa and difficulty in incision on cystoscopy, SE findings had a significant association (p<0.001) with histopathology findings for severe degree of fibrosis. Sonoelastography estimates stricture site and length better in comparison with RUG and SUG. It estimates degree of spongiofibrosis which serves as an important prognostic factor for stricture recurrence more accurately than SUG.