Purpose: To describe the clamp method for performing retrograde sonourethrography (RSUG) and contrast-enhanced voiding sonourethrography (CE-VSUG) via the transperineal approach in male adults.
Materials and methods: Prospective study of 113 males (14-86 years) with urethral strictures confirmed by urethrography who received sonourethrography via the clamp method between 2011 and 2015. The characteristic parameters of the quantitative variables were calculated and a comparative analysis of the qualitative variables was conducted using the McNemar test.
Results: RSUG was performed successfully in all the cases (n = 113) and detected 49 cases with anterior urethral strictures; the strictures in the proximal bulbar cone in five of them (10.2%) were not visualised on retrograde urethrography (RUG) (p < 0.05). CE-VSUG was performed successfully in 97 cases and observed posterior urethral strictures in 82; the bladder neck strictures in 6 of them (7.3%) were not observed on voiding cystourethrography (VCUG) (p < 0.05). Retrograde bladder filling was achieved in approximately 6 min.
Conclusion: The clamp method enables RSUG and CE-VSUG to be performed simply, effectively and painlessly by a single operator. It also allows the evaluation of cases with urethromeatal alterations (stricture, hypospadias and meatotomy).
Key points: • The clamp method enables RSUG to be performed simply and painlessly. • The clamp method requires only one operator and allows assessing urethromeatal alterations. • RSUG shows greater capacity for detecting anterior urethral strictures than RUG. • The clamp method achieves retrograde bladder filling in approximately 6 min. • CE-VSUG shows greater capacity for detecting strictures than VCUG.
Keywords: Clamp method; Sonourethrography; Ultrasound contrast; Urethral stenosis; Urethrography.