Electromotive administration of intravesical bethanechol and the clinical impact on acontractile detrusor management: Introduction of a new test

Purpose: It is often difficult to determine the functional status of the de trusor muscle in patients with detrusor areflexia. We performed a clinical study to establish a test defining residual detrusor capacity in such patie nts. Materials and Methods: In phase 1, 5 controls with detrusor areflexia were tested with an intravesical instillation of 20 mg. bethanechol in 150 cc of sodium chloride 0.3% with and without 20 mA. of pulsed current applied via an electrode catheter through the saline. Cystometry simultaneously record ed intravesical pressure changes. In phase 2, 45 patients with detrusor are flexia were tested with electromotive administration of intravesical bethan echol. In phase 3, 25 mg. bethanechol given orally once daily were prescrib ed for 15 patients and voiding control was assessed after 6 weeks of therap y. Results: Neither bethanechol without current nor current through saline onl y led to increased intravesical pressure. However, we noted a mean pressure increase of 34 cm. water during the electromotive administration of bethan echol in 24 of 26 patients with areflexia and neurological disease compared to only 3 cm. water in 3 of 11 with a history of chronic bladder dilatatio n. Oral bethanechol restored spontaneous voiding in 9 of 11 patients who ha d had a positive response to the electromotive administration of bethanecho l, whereas all 4 without a pressure increase during the electromotive admin istration of bethanechol did not void spontaneously. Conclusions: Electromotive administration of intravesical bethanechol ident ifies patients with an atonic bladder and adequate residual detrusor muscle function who are candidates for restorative measures, such as oral bethane chol and intravesical electrostimulation. Those who do not respond to the e lectromotive administration of bethanechol do not benefit from oral bethane chol and are candidates for catheterization.