Mechanical failure of inflatable penile prostheses: time to failure and reasons for replacement.

Abstract

Background: Despite advancements in the composition material, pump design, and infection retardant coatings, inflatable penile prosthetics (IPPs) remain prone to mechanical failure.

Aim: To distinguish IPP mechanical failure etiologies and time to failure among the 2 most common manufacturers: American Medical Systems/Boston Scientific (BSCI) and Coloplast (CP).

Methods: A retrospective chart review of 2 high-volume IPP surgeon revision and virgin cases was conducted from January 2018 to September 2023. Mechanical revision indications were stratified by brand and component location (pump, tubing, cylinder, and reservoir), while non-mechanical revision cases and those with missing data were excluded. Subgroup analysis regarding the cylinder rupture rate between BSCI controlled-expansion (Cx) ≤18 vs ≥21 cm devices was also performed. Categorical variables were assessed with chi-square or Fisher exact analysis, while continuous variables were evaluated with Student and Mann-Whitney U tests. The log-rank test was used to compare BSCI component-specific survival.

Outcomes: Outcomes included time to failure, site-specific mechanical failure location in IPPs among BSCI and CP devices, and cylinder rupture rate among ≤18 vs ≥21 cm BSCI (Cx) cylinders.

Results: We identified a total of 410 cases: 220 BSCI and 190 CP devices. One hundred twenty-nine were revisions. Seventy-two met the inclusion criteria (63 BSCI and 9 CP). BSCI mechanical failures included: cylinder rupture, 26/63 (41.3%), tubing fracture, 7/63 (11.1%), reservoir rupture, 3/63 (4.8%), cylinder aneurysm, 6/63 (9.5%), and pump failure, 21/63 (33.3%). Coloplast mechanical failure included: tubing fracture 7/9 (77.8%), while reservoir rupture and cylinder aneurysm each were 1/9 (11.1%). Time to mechanical failure was a median of 48 and 41 months, respectively, for BSCI and CP devices.

Clinical implications: Mechanical failure site distribution between device manufacturers is significant and should be considered during primary and revision cases.

Strengths and limitations: This study adds to the literature indicating when and where mechanical failure occurs in IPPs between the 2 major IPP manufacturers. Collaborative prospective studies would provide a more robust evaluation.

Conclusions: The current study provides a breakdown of failure modes for contemporary 3-piece inflatable penile prostheses. Larger series are required to validate findings.