Complication Rates and Outcomes of Suction Devices in Ureteroscopy and Retrograde Intrarenal Surgery: A Systematic Review

Systematic review of 35 studies finds suction-assisted ureteroscopy improves stone clearance and cuts infection risk, but high-quality evidence is scarce.

Journal: BJU International | Published: 2025-11-06 | Type: Systematic Review | PMID: 41199419 Authors: Crisafi D, Santucci J, Hong A, Sii S, Bolton D, Jack G (Department of Urology, Austin Health, Melbourne, Australia) Funding/COI: Not reported

Summary

Retrograde intrarenal surgery (RIRS) — threading a flexible scope up the ureter to laser kidney stones — has a visibility problem: debris clouds the operative field, fragments escape, and pressure buildup in the kidney can drive bacteria into the bloodstream. This review pooled 35 studies on suction-assisted RIRS devices designed to fix those problems. The technology appears to work on its own terms: better stone clearance, shorter operating times, and fewer post-operative infections. The catch is that "35 studies" is doing a lot of work here — none of the included evidence rises to the level that would normally justify clinical standardisation.

Claims

• Suction ureteric access sheaths, tip-flexible variants, in-scope suction, and aspiration catheters all showed improvements in stone-free rates and operating time across included studies
• Continuous negative pressure reduces intrarenal pressure (IRP) intraoperatively, with intelligent monitoring systems associated with lower rates of post-operative fever and sepsis
• Some suction-assisted RIRS approaches demonstrated stone clearance for larger stones previously reserved for percutaneous nephrolithotomy (PCNL) — a more invasive procedure requiring flank puncture
• Proposed health economic benefits include reduced operating time, fewer auxiliary procedures, and shorter hospital stays
• 35 total articles met inclusion criteria; no pooled quantitative data (no meta-analysis) is reported in the abstract

Study Quality

This is a narrative systematic review, not a meta-analysis. The authors searched Embase, Medline, and Scopus through December 2024 and restricted inclusion to adult populations with typical anatomy — reasonable scope limitations. However, the absence of pooled effect sizes, heterogeneity statistics, or GRADE-level evidence assessment (none mentioned in the abstract) makes it impossible to quantify how much benefit suction devices actually provide. The review synthesises a literature the authors themselves describe as lacking "high-level evidence," which limits what any systematic review of it can conclude.

The review is also limited to English-language publications, a standard but relevant bias in a field where Asian centres (China, South Korea, Japan) produce substantial urolithiasis research and likely have significant experience with these devices.

Red Flags

• No meta-analysis: 35 studies are summarised but not statistically pooled, so effect sizes remain impressionistic
• Funding and conflicts of interest not reported — suction device manufacturers have obvious commercial interest in this literature, and several of these devices are proprietary products
• Conclusion language ("promises to be a useful adjunct") exceeds what the evidence base can support by the authors' own admission
• No breakdown of included study types — how many RCTs vs. retrospective case series matters enormously here
• "Larger stones typically managed by PCNL" claim is clinically significant but no specific stone-size thresholds or stone-free rate comparisons are given
• Restricted to English language, likely missing a meaningful share of relevant Asian literature

Strengths

• Addresses a clinically relevant and active area: RIRS device technology is evolving rapidly and a synthesis of the complication/outcomes literature is useful
• Covers multiple suction modalities (sheaths, in-scope, aspiration catheters) rather than a single product
• Identifies IRP control as a distinct mechanism for infection reduction — this is a plausible biological pathway, not just a marketing claim
• Authors explicitly flag the evidentiary limitations rather than overselling their findings

Verdict

Honest about its own ceiling. Crisafi et al. reviewed a young, commercially active literature and correctly identified that the evidence isn't yet strong enough to standardise these devices — then said so. What the review cannot do is tell you how much suction-assisted RIRS improves outcomes, because the included studies almost certainly vary too widely in design, stone characteristics, and suction technique for that number to exist yet. File this as a useful map of the current technology landscape, not proof that any particular device works.