[Urinary bladder plastic enlargement with the use of autologous, homologous and heterologous skin transplants].

1. Expanded urinary bladder resection and the following replacement of the defect with various skin grafts were well tolerated by 161 cats. 2. Grafts of various species were shown to be of significantly different biomechanical properties. This depended on basic substance, compound and texture of collagenous and elastic fibres and the methods of conservation. Preoperatively the transplants were sufficiently resistent against urine and bladder pressure. 3. Within of few weeks postoperatively there was an increase in bladder capacity. This was more evident and arose in an earlier period than in cases without bladder wall replacement (x-ray-control). 4. Autologous grafts were infiltrated by young new tissue. Homologous and heterologous patches served as "guide" of regeneration. Complete transitional cell epithelium was proven to be present after four weeks in the predominantly connective tissue regenerates. The development of smooth muscle fibres in the regenerates is discussed. 5. The microcytotoxicity test showed a host response, but without clinically manifest rejection of the foreign transplants. 6. Apart from clinical urological application the results of this experimental investigation could be useful in general plastic surgery.