[Effects of the pelvic and hypogastric nerve transection on the micturition cycle in the decerebrate dogs].

The effect of the transection of the pelvic and hypogastric nerves on the whole micturition cycle including the collecting and emptying phases was evaluated on the decerebrate dogs which exhibit highly consistent urodynamic parameters during a series of micturition cycles. Urodynamic parameters of each phase before and after each nerve transection were measured by pressure flow electromyographic studies and compared using the paired t test. Urodynamic parameters in the collecting phase consisted of threshold volume, threshold pressure, opening pressure and bladder compliance. Urodynamic parameters in the emptying phase consisted of voided volume, residual volume, residual ratio, contraction pressure, maximum flow rate and voiding time. Unilateral pelvic nerve transection produced a significant increase in threshold volume and bladder compliance and a significant decrease in threshold pressure during the collecting phase. There was a significant increase in residual volume and residual ratio and a significant decrease in contraction pressure and maximum flow rate during the emptying phase. After bilateral pelvic nerves transection, bladder did not contract and overflow incontinence occurred. Therefore, the pelvic nerves are considered to play an important role in both the collecting and emptying phases. Unilateral hypogastric nerve transection produced a significant decrease in threshold volume, threshold pressure and opening pressure during the collecting phase. There was a significant decrease in contraction pressure during the emptying phase. Bilateral pelvic nerve transection produced a significant decrease in threshold volume, threshold pressure and opening pressure, and a significant increase in bladder compliance during the collecting phase. There was a significant decrease in voided volume and contraction pressure during the emptying phase. Therefore, the hypogastric nerves are considered to play a certain role in the collecting phase.