CARTILAGE RODS AS A POTENTIAL MATERIAL FOR PENILE RECONSTRUCTION

Purpose: Sex assignment is made in patients with ambiguous genitalia, genital trauma or iatrogenic injury after a thorough diagnostic evalua tion and careful consultation with the family. In numerous instances a decision is made to rear the child as the female gender due to inadeq uate genitalia regardless of karyotype. Although a silicone penile pro sthesis is accepted treatment in adults who require penile reconstruct ion, it has not been generally used in the pediatric population, mainl y due to associated long-term problems. We determine the feasibility o f creating natural penile prostheses of cartilage which, if biocompati ble and elastic, may be used in patients who require genital reconstru ction. Materials and Methods: Cartilage was harvested from the articul ar surface of calf shoulders. Chondrocytes were isolated, grown and ex panded in vitro. Cells were seeded onto preformed cylindrical polyglyc olic acid polymer rods 1 cm. in diameter and 3 cm. long at a concentra tion of 50 x 10(6) chondrocytes per cm(3).. A total of 40 polymer scaf folds were implanted in the subcutaneous space of 20 athymic mice. In each mouse 2 implantation sites consisted of a polymer scaffold seeded with chondrocytes and a control (polymer alone). Mice were sacrificed 1, 2, 4 and 6 months after implantation, respectively. Stress relaxat ion studies to measure biomechanical properties, including compression , tension and bending, were performed on the retrieved structures. His tological analyses were done with hematoxylin and eosin, aldehyde fuch sin-alcian blue and toluidine blue staining. Results: Gross examinatio n revealed well formed, milk-white rod-shaped solid cartilaginous stru ctures the same size as the initial implant. Compression, tension and bending studies demonstrated that the cartilaginous structures-were re adily elastic and withstood high degrees of pressure. Histochemical an alyses showed mature, well formed chondrocytes in all implants. There was no evidence of cartilage formation in the controls. Conclusions: C hondrocytes seeded on preformed biodegradable polymer structures form cartilage rods. The use of an entirely autologous system composed of b iodegradable polymers and chondrocytes precludes an immunological reac tion. This technology appears to be useful for the creation of a bioco mpatible malleable penile prosthesis, which may be useful in children with ambiguous genitalia and patients undergoing penile reconstruction .