Complete external sphincterotomy: correlation between endoscopic observation and the anatomic sphincter

Longitudinal cuts of various lengths and depths were made in the area of the external urethral sphincter in 18 male cadavers. The Iglesias resectoscope and the Collings knife electrode were used. Histologic sections of the prostate and of the membranous and bulbous urethra demonstrated that a cut of 2 cm. in length beginning from the verumontanum and 6 mm. in depth was necessary to completely incise the external urethral fibers. This procedure, when performed according to these criteria, effectively decreases urethral resistance, permits adequate bladder emptying and probably eliminates the need for a catheter.