Long-term survival of inflatable penile prostheses: single surgical group experience with 2,384 first-time implants spanning two decades

Abstract

Introduction: Long-term revision-free survival, greater than 10 years has never been reported for inflatable penile prostheses. We conducted a historical prospective study to estimate 10 and 15 years survival of first time (virgin) implantations in 2,384 patients with four different models.

Aim: Evaluation of 10- and 15-year mechanical and overall revision-free survival of inflatable penile prostheses.

Main outcome measures: Kaplan-Meier product limit method, and comparison using the log rank test, were used to estimate the 10- and 15-year revision-free survival.

Methods: Data were obtained from medical records and patient interviews, entered into a computerized database, and analyzed by a third party. Information included implant type, date, revision history with date, and reason. Fourteen different inflatables were examined. Mentor Alpha 1, Mentor Alpha NB, AMS 700 CX, and AMS 700 Ultrex had usage for an extended period of time. Because of failure times being confounded as a result of prior implants, only virgin implants were examined.

Results: For the entire series, estimated 10-year revision-free survival for all reasons was 68.5% and the 15-year revision-free survival was 59.7%. Freedom from mechanical breakage at 10 years was 79.4%; 15 years was 71.2%. Recent mechanically enhanced models did even better. In 1992, Mentor Alpha added pump reinforcement to forestall mechanical breakage. This improved 10-year survival from 65.3% to 88.6% (P = 0.0001). In January 2001, AMS CX added a parylene coating to the cylinders that increased 3-year mechanical survival from 88.4 to 97.9% (P = 0.0002).

Conclusions: This is the first report on long-term reliability of inflatable penile prostheses. We estimated 60% of these virgin implants would survive 15 or more years without revision or extraction. Newer enhanced models are currently available, and our tracking predicts even better long-term survival for these devices.