STUDY DESIGN: Prospective, open label, cross-over-designed clinical study.
OBJECTIVE: To evaluate the effectiveness of an instillation of lidocaine into the bladder with versus without electromotive drug administration (EMDA) to anesthetize the bladder before botulinum-A toxin injections.
SETTING: Neurourology, Swiss Paraplegic Center, Balgrist University Hospital, Zurich, Switzerland.
METHODS: In all, 28 patients with severe neurogenic detrusor overactivity but preserved bladder sensibility were treated with botulinum-A toxin injections into the detrusor muscle. A measure of 300 u of botulinum-A toxin (Botox) was injected at 30 sites sparing the trigone. Prior to the injection, the bladder was anesthesized with conventional lidocaine instillation in a group of 10 patients and with lidocaine instillation enhanced by EMDA in 28 patients. The patients scored the injection pain on a 10-point rating scale. Pain rating scores with versus without EMDA enhancement of the lidocaine instillation were analyzed and the costs of the EMDA procedure were compared to general/spinal anesthesia.
RESULTS: The mean pain score of the 10 patients who underwent the injections of Botox after conventional lidocaine instillation was 4.0 (SD 1.6). Following EMDA enhanced lidocaine instillation slight even or no pain occurred during the injections of Botox, and the mean pain score was 0.5 (SD 0.2). Compared to spinal or general anesthesia, the local anesthesia saved around 15% of the costs.
CONCLUSIONS: EMDA enhanced instillation of lidocaine enables a sufficient anesthesia of the bladder wall that ensures a painless application of the botulinum-A toxin injections into the detrusor muscle. This method may avoid general or spinal anesthesia in patients with preserved bladder sensibility. It ensures considerable cost reduction, avoids anesthesia-related risks and complications and enables the procedure on an outpatient basis.