Removal Rate and Mechanical Failure in Penile Prosthesis Implantation: A Systematic Review

Across 30 studies, penile implant removal rates were generally below 10%, but one newer device (Zephyr ZSI 475®) showed a 25.7% early mechanical failure rate.

Journal: International Journal of Impotence Research | Published: 2025-09-13 | Type: Systematic Review | PMID: 40940535 Authors: Lo Re Mattia et al. (University of Florence; Hospital HM Sanchinarro, Madrid; 12 de Octubre University Hospital, Madrid) Funding/COI: Funding not reported; authors declare no conflicts of interest.

Summary

This systematic review assessed safety and durability across four inflatable penile prosthesis brands — AMS 700®, Coloplast Titan®, Rigicon Infla 10®, and Zephyr ZSI 475® — drawing on 30 studies published between 1994 and 2023. Most established devices performed reasonably well over long follow-up, with removal rates generally below 10% and infection rates under 5%. The newer Zephyr device stands out for the wrong reasons: a 25.7% early mechanical failure rate, though data remain limited.

Claims

• Removal rates across all devices ranged from 0% to 52.9%, with most studies reporting below 10%
• Infection rates were typically under 5%
• AMS 700® removal rates: 0.3%–52.9% across studies; mechanical failure rates: 0%–37.3%
• Coloplast Titan® removal rates: 0%–6.2%; mechanical failure rates: 0%–9.1% (with generally shorter median follow-up)
• Rigicon Infla 10® mechanical failure rate: 2–3%, but based on short follow-up only
• Zephyr ZSI 475® initial mechanical failure rate: 25.7%
• Follow-up duration ranged from 12 to 206 months across included studies

Study Quality

This is a PRISMA-compliant systematic review covering 30 studies over nearly three decades. That's a reasonable methodological foundation, but the review is largely descriptive — it reports ranges of outcomes across heterogeneous studies rather than pooling data in a meta-analysis, which means no summary effect sizes and no statistical comparisons between devices. The wide ranges for the same device (AMS 700® removal from 0.3% to 52.9%) reflect substantial heterogeneity in patient populations, surgical technique, follow-up duration, and how outcomes were defined — but the authors do not formally quantify or report that heterogeneity.

The device comparisons are further undermined by asymmetric follow-up: AMS 700® and Coloplast Titan® have studies running up to 17 years, while Rigicon and Zephyr data are short-term only. Comparing failure rates across that gap is apples to oranges.

Red Flags

• No meta-analysis performed — results reported as ranges, not pooled estimates; cross-device comparisons are unreliable
• Massive variance in reported outcomes for the same device with no formal heterogeneity assessment
• The 52.9% upper-bound removal rate for AMS 700® is a dramatic outlier that is never explained or contextualized
• Newer devices (Rigicon, Zephyr) compared against brands with decades of follow-up data — structurally unfair comparison
• Funding for the systematic review itself is not disclosed; funding of the 30 included primary studies is not discussed
• No sub-group analysis by era, surgeon volume, or patient comorbidities despite a 30-year study span

Strengths

• PRISMA guidelines followed, providing methodological transparency
• Covers infection, removal, and mechanical failure together rather than any single endpoint
• Long time horizon (1994–2023) captures mature outcome data for established devices
• Includes both well-studied and newer devices in the same frame
• No conflicts of interest declared

Verdict

This review does what a systematic review without a meta-analysis can do: it organizes the literature and flags where the evidence is thin. It confirms that AMS 700® and Coloplast Titan® have decades of real-world data behind them, and it raises a legitimate concern about the Zephyr ZSI 475®'s 25.7% early mechanical failure rate. But without pooled analysis, the wild variance in reported outcomes, and the incomparable follow-up durations between devices, this paper is a literature map — not a comparative effectiveness study. The 52.9% removal rate sitting unexplained in the abstract is a sign that the authors leaned too heavily on reporting raw ranges without interrogating the outliers. Worth reading for orientation; don't expect it to resolve which device holds up longest.