a method for repairing defects and reconstructing urological structures in vivo has been developed using a fibrous , open , synthetic , biodegradable polymeric matrix which is configured to provide the desired corrective structure . the matrix is shaped to correct the defect , then implanted surgically to form a scaffolding for the patient &# 39 ; s own cells to grow onto and into . the implantation of the matrix initiates an inflammatory reaction , resulting in urothelial cells , endothelial cells and mesenchymal cells migrating into the matrix . the polymer forming the matrix is selected to be biocompatible and degradable in a controlled manner over a period of one to six months , in the preferred embodiment . a preferred material is a poly in a fibrous form , such as a woven or non - woven mesh . examples demonstrate the repair of defects in bladder and urethra in rabbits and defects in ureter in dogs .