THE BIOLOGICAL BEHAVIOR OF AUTOLOGOUS COLLAGEN INJECTED INTO THE RABBIT BLADDER

Growing interest in the endoscopic treatment of vesicoureteral reflux and urinary incontinence has led to the development of safe reliable t echniques that use an injectable bulking agent. A variety of injectabl e materials has been studied, such as polytetrafluoroethylene, fat and bovine collagen. We evaluated autologous collagen extracted from the dermis of skin for potential use in the urinary tract. Therefore, an a nimal model was developed to study the biological behavior of autologo us collagen within the bladder. Collagen was extracted from the skin o f rabbits and radiolabeled with (125)iodine. An aliquot of radiolabele d autologous collagen was injected submucosally in the bladder. The an imals were monitored weekly under a gamma camera. The decay of the rad iolabeled collagen was recorded during 50 days. The animals were then sacrificed and the bladder wall at the site of injection was studied h istologically and on electron microscopy. Decay of the injected collag en within the urinary tract was similar to control material, indicativ e of good stability within the bladder, A mild inflammatory response w ith fibroblastic and vascular invasion of the collagen implant was obs erved. These preliminary data suggest that autologous collagen injecte d endoscopically can provide a safe reliable bulking material that cou ld be used to treat urinary incontinence and lower grades of vesicoure teral reflux in children,