Early Outcomes After Discontinuing Routine Gentamicin Irrigation During AMS 800 Artificial Urinary Sphincter Implantation: A Single-Centre Retrospective Before-After Cohort Study.

Background/

Objectives

Routine local gentamicin irrigation has been used during artificial urinary sphincter (AUS) implantation despite limited procedure-specific evidence. We evaluated early outcomes after its calendar-defined discontinuation.

Methods

This single-centre retrospective before-after cohort included 173 uncoated AMS 800 procedures in 164 men: 59 under a gentamicin-containing local protocol and 114 after gentamicin withdrawal. Saline device immersion and Betadine-containing intraoperative irrigation of the operative field and both wounds continued in both periods. Clinician-recorded surgical-site infection (SSI) within 90 days was the antimicrobial outcome of greatest direct relevance. Complete explantation within 90 days for SSI and/or urethral erosion was an exploratory device-related endpoint; all-cause complications at 30 and 90 days were secondary safety outcomes.

Results

SSI occurred after 1/59 (1.7%) gentamicin-protocol and 2/114 (1.8%) gentamicin-free procedures (risk difference +0.1 percentage points, 95% confidence interval -7.4 to +4.7; p = 1.000). Erosion occurred after 0/59 and 4/114 (3.5%) procedures; all four led to complete explantation. The explantation endpoint occurred after 1/59 versus 4/114 procedures (risk difference +1.8 percentage points, 95% confidence interval -5.8 to +7.2; p = 0.662). Thirty-day all-cause complications occurred after 14/59 versus 16/114 procedures and 90-day complications after 15/59 versus 26/114.

Conclusions

No statistically significant between-period difference was detected in SSI, exploratory device-related explantation, or broad all-cause complications. Sparse events, wide confidence intervals and calendar-defined exposure amid concurrent era changes preclude conclusions regarding equivalence or absence of clinically relevant benefit or harm.