Ultrastructural changes in impotent penile tissue: a comparison of 65 patients. To determine whether impotence is caused by specific and consistent changes in erectile tissue, we compared the ultrastructure of the corpora cavernosa in 6 controls with that in 59 patients undergoing implantation of a penile prosthesis. The impotent patients were divided into groups based on a medical history of hypertension (10), pelvic surgery (9), alcoholic smokers (8), hypertensive alcoholics (3), hypertensive alcoholic smokers (3), smokers (3), diabetics (8), diabetic smokers (3), Peyronie's disease (3), spinal cord injury (3) and isolated causes (6). Our data demonstrate that different behavioral and/or medical conditions produce similar degenerative tissue responses. There is no single or specific cause of impotence that is manifest by consistent changes in erectile tissue. 