Intraoperative endo-luminal ultrasound evaluation of urethral diverticula

The imaging accuracy of a catheter-based endo-luminal ultrasound system was compared to traditional imaging techniques for surgical treatment of urethral diverticula in 7 women and 1 man. At surgical repair the urethra was catheterized directly with a 6.2F or 9F (12.5 or 20 MHz.) catheter-based ultrasound transducer, generating a 360-degree transaxial real-time image. The endo-luminal ultrasound images were compared with preoperative voiding cystourethrography (7 patients), transvaginal ultrasound examinations (3) and double balloon urethrograms (2). Surgical diverticulectomy was then done with endo-luminal ultrasound monitoring. Intraoperatively, all diverticula were well visualized by endo-luminal ultrasound, which demonstrated improved identification of the size and orientation of urethral diverticula, sludge within the diverticula, the extent of periurethral inflammation, diverticular wall thickness, and the distance between the diverticular wall and urethral lumen. In 3 patients the urethral connections of the diverticula were exceptionally well visualized. Comparison with traditional imaging revealed 2 false-negative and 1 false-positive voiding cystourethrograms, 1 false-negative transvaginal ultrasound study and 1 false-negative double balloon urethrogram. Intraoperative monitoring of the urethra enabled precise anatomical dissection, eliminated all diverticular components, and prevented inadvertent urethral and bladder neck injury. Urethral endo-luminal ultrasound is a valuable new adjunct in the evaluation of a variety of urethral abnormalities. This new ultrasound application permits visualization of the precise size, location, orientation and characteristics of urethral diverticula and surrounding tissues. Through enhanced imaging, surgical repair is facilitated. Further application of this technique should increase the diagnostic accuracy of urethral imaging beyond radiographic techniques currently available.