Hydrodynamics of micturition following Marshall-Marchetti-Krantz procedure for stress urinary incontinence.

Nineteen stress-incontinent females have passed a urodynamic study before and six months after Marshall-Marchetti-Krantz (M-M-K) surgical procedure. It is concluded that postoperative changes in the urethral pressure profile are very limited. However, urethral closure pressure was elevated and functional length shortened, both probably statistically significantly. Synchronous pressure-flow studies pre- and post-operatively showed only slightly and not statistically significantly decreased peak-flow values for three different micturition volumes at detrusor micturitions. At straining micturitions peak-flow was significantly reduced. For small micturition volumes (200 ml) detrusor pressure at peak-flow and at maximum detrusor contraction was significantly elevated after surgery. Urethral resistance was significantly increased for 200 ml and 400 ml micturitions postoperatively, but at micturition with maximum bladder capacity no changes were found. If micturitions are made as detrusor micturitions without strain and with an adequate filling of the bladder, the changes found postoperatively hardly bear clinical significance. Micturitions with heavy straining postoperatively, however, give a reduced flow and increased residual urine to the extent that micturitions in this way should be avoided.