Clinical experience with Mentor inflatable penile prosthesis in 206 patients.

The Mentor inflatable penile prosthesis (IPP) has been implanted in 206 patients with organic (95.2%) or psychologic (4.8%) impotency. The patients have been followed up for an average of 18.1 (4-42) months. A satisfactory result has been achieved in 98 per cent of these patients. A life analysis of the series shows that 88 per cent of all devices implanted will survive forty-two months without mechanical failure. One hundred sixty-four of these patients had not had previous penile surgery while 42 had had one or more penile prostheses implanted previously. The projected forty-two-month survival for the Mentor prosthesis in these subgroups is 94 per cent and 74 per cent, respectively. The improved life expectancy of the Mentor IPP, compared with the Scott IPP, is due to the superior durability of Mentor's polyurethane cylinders and to the increased reliability of the Mentor snap-on connector system. In this respect, there have been only one cylinder failure and 3 connector failures in the Mentor series. The connector failures occurred early in the series before the development of connector pliers; there have been no connector failures in the last 202 consecutive implantations. Wear-induced tubing leaks, the most common cause of device failure, occurred in 2.9 per cent of all implantations. Tubing failures were more common in patients who have had previous surgery, occurring in 9 per cent of salvage procedures and 1.3 per cent of primary implantations. The reason for the difference in tubing survival in virgin and salvage procedures is unknown; possibly the subcutaneous scar tissue present in secondary surgical procedures increases the chance of tubing segments touching and abrasing each other. Laboratory studies suggest that the nylon-reinforced tubing used in the manufacture of devices implanted since 1985 is more durable than is the standard silicone tubing used in the construction of devices implanted previously.