Detachable self-sealing membrane system for the endoscopic treatment of incontinence

The endoscopic treatment of urinary incontinence is limited by the injectable substances currently available. The ideal injectable material should be able to conserve its volume, be nonmigratory and nonantigenic. Toward this goal we developed a system for the treatment of incontinence in which a catheter with an inflatable and detachable self-sealing silicone membrane fits through a standard cystoscopic needle. We present our experience with this system.

A total of 20 female beagle dogs underwent cystoscopy and in 15 a self-sealing membrane was placed endoscopically in the submucosal region of the proximal urethra at the 3 and 9 o'clock positions. Each membrane was inflated through the delivery catheter with 0.2 cc povidone. Coaptation of the urethra due to the relative bulking effect of the inflated membrane was confirmed endoscopically in each animal. Five control animals received only an injection of saline. Four animals were sacrificed at 1, 3, 6, 12 and 18 months, respectively. At sacrifice gross and histological examinations were performed.

At retrieval up to 18 months after implantation the membrane remained inflated and at the same position at which it had been initially placed. There was no evidence of povidone volume loss or extravasation. Membranes were encapsulated by a fibrous capsule. Only a few inflammatory cells surrounded the capsule by month 1 and there were none by month 3. Histological examination of periurethral tissue and distant organs showed no evidence of particle migration.

The detachable self-sealing membrane system is easily implantable, nonmigratory, nonantigenic and able to conserve its volume. These studies indicate that this system may be effective for the endoscopic treatment of incontinence.