Preoperative simulation by volume rendering image and intraoperative navigation by ultrasound for posterior...

In posterior urethroplasty, exposure of the proximal urethral stump is the most important step that determines surgical outcome. However, this is sometimes difficult due to deviation of the prostate or overlying scar tissue. We present a novel preoperative simulation and intraoperative navigation method for this step.

Three patients underwent excision and primary anastomosis for posterior urethral disruption after pelvic fracture. Preoperatively, volume-rendering image of the posterior urethra was constructed from gadolinium-enhanced magnetic resonance image, enabling simulation from the viewpoint of the operator in all three cases. Intraoperative navigation was performed in two patients by using transrectal ultrasound, visualizing the acoustic shadow of a cystoscope inserted into the prostatic urethra via the cystostomy tract. The overlying scar tissue was removed toward the urethral stumps identified by navigation. Urethroplasty was successful in all three patients.

The present methods were useful for precise identification of the proximal urethral stump.