The importance of separation of prostatic lobes in relief of prostatic obstruction by balloon catheter urethroplasty: studies in dogs and humans.

We performed balloon urethroplasty in six older normal dogs and 10 patients with benign prostatic hypertrophy to establish the mechanism by which this technique results in relief of bladder outlet obstruction. Thirty-millimeter balloon catheters were used in both the animal and human studies. Autopsy studies showed disruption of the anterior prostatic commissure in four of the six dogs, disruption of both anterior and posterior commissures in one dog, and no disruption in the remaining dog. In all 10 patients, cystoscopy and urethrography showed disruption of the anterior commissure. Separation of the prostatic lobes by disruption of the prostatic commissures may be the most important mechanism by which balloon urethroplasty relieves urethral obstruction.