Electrically stimulated detrusor myoplasty

Purpose: Many children with spina bifida and other causes of neurogenic bla dder rely on clean intermittent catheterization to empty the hyporeflexic o r areflexic bladder. Direct bladder and sacral nerve root stimulation have been met with limited success. We studied the electrical stimulation of a r ectus abdominis muscle flap wrapped around the bladder to achieve bladder c ontractility and emptying. Materials and Methods: The feasibility of performing rectus detrusor myopla sty in humans was first studied in 8 cadavers. In male and female cadavers it was possible to wrap the distended bladder completely with the rectus ab dominis muscle. The rectus abdominis muscle was surgically dissected with p reservation of its insertion on the pubis bone and rotation of its mid sect ion behind the bladder to effect a complete bladder wrap. The deep inferior epigastric artery and veins, and 2 most caudal intercostal nerves were pre served. This unilateral rectus abdominis muscle flap was then electrically stimulated with 2 pairs of bipolar electrodes inserted into the muscle near the nerve entrance. Stimulation frequencies of 40, 60 and 80 Hz. were used in each of the 8 dogs. The increase in intravesical pressure over baseline , compliance and post-void residual were measured. Paired Student's t tests were used for statistical comparisons. Results: The increase in intravesical pressure ranged 35 +/- 5 to 45 +/- 7 cm. H2O at stimulation frequency 40 and 80 Hz., respectively. Post-void res idual was 27 +/- t4%, 22 +/- 3% and 26 +/- 3% at stimulation frequencies 40 , 60 and 80 Hz., respectively. Intravesical pressure was significantly incr eased over baseline bladder pressure (p < 0.05). Conclusions: Electrically stimulated detrusor myoplasty results in uniform increases in intravesical pressure and reasonable bladder emptying in an an imal model. We are currently investigating detrusor myoplasty in a chronic study to determine whether it can be used for enhanced bladder emptying in children with poor detrusor contractility.