The Mentor Alpha 1 Penile Prosthesis With Reservoir Lock-out Valve: Effective Prevention of Auto-inflation With Improved Capability For Ectopic Reservoir Placement

Abstract

Auto-inflation is a common and annoying complication of 3-piece penile prostheses. In the published literature the rate is approximately 11% with a 2% operative revision rate. We report the results of a review of 160 Alpha 1 and NB implants (Mentor Corp., Santa Barbara, California) with the new lock-out valve located on the reservoir to treat impotence. We compared it with 339 Alpha 1 implants with the standard reservoir. We also investigated the lock-out reservoir for ectopic nonretropubic implantation. We compared 339 Alpha prostheses with the standard reservoir that were implanted between January 1, 1998 through December 31, 1999 and 160 with the new lock-out valve placed since January 2000 with at least 6 months of followup. Implants were further stratified as first time (virgin) or revision-replacement of a previous implant. In 8 patients with a scarred or obliterated retroperitoneal space the lock-out reservoir was placed superior to the transversalis fascia and beneath the abdominal musculature. Kaplan-Meier estimated 1-year survival was not significantly different in terms of mechanical failure (p = 0.57 and 0.85) revision for any cause (p = 0.92 and 0.92), patient dissatisfaction (p = 0.35 and 0.11) or infection (p = 0.64 and 0.94) for all implants and virgin implants only, respectively. Only 2 patients (1.3%) with a lock-out valve complained of auto-inflation initially and the problem resolved in each after instruction on how to operate the device. Of the patients in the earlier series 11% complained of auto-inflation and 2% required operative correction. None of the 8 patients with an ectopic reservoir location complained of auto-inflation. Our results indicate that the lock-out valve prevents early auto-inflation. Addition of the lock-out valve does not impact the revision rate compared with the same implant with a standard reservoir. In patients with a scarred retropubic space the lock-out valve offers the penile implant surgeon a decreased probability of auto-inflation with ectopic reservoir placement.