Home›Urology› Intraoperative Positioning Strategies Raise Stone-Free Rates in RIRS for Renal Calculi
Intraoperative Positioning Strategies Raise Stone-Free Rates in RIRS for Renal CalculiNew Positioning Strategies May Improve Success Rates for Kidney Stones
World journal of urologyPublished September 30, 2026Study authors: Wang Lin, Huang Wen, Wan Bin, Luo Zhifang, Wen Xiaoyan, Feng Mei, Jia QileiPubMed ↗DOI ↗Editorial oversight: Dr. Lars van Dijk, PhD · Surgical, Procedural & Diagnostic
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Key Takeaway
Consider positioning strategies in RIRS to improve stone-free rates, but note limited certainty.
This meta-analysis examined intraoperative positioning strategies versus standard lithotomy in patients undergoing retrograde intrarenal surgery (RIRS) for renal calculi, pooling data from 998 patients. The primary outcome, stone-free rate, was significantly increased with positioning strategies (RR 1.20, 95% CI 1.12-1.28, P < 0.001). Postoperative fever did not differ significantly between groups (RR 1.15, 95% CI 0.53-2.53, P = 0.720).
The authors report that positioning strategies may improve stone-free outcomes during RIRS. However, the certainty of these findings is limited by several factors noted in the analysis: endpoint variability, exploratory subgroup classification, limited reintervention data, and the absence of direct intrarenal pressure monitoring. Operative time, hospital stay, and reintervention outcomes were not sufficiently reported to draw firm conclusions, and the authors caution against overstating these endpoints.
Safety data were limited to postoperative fever, which showed no significant difference. Serious adverse events, discontinuations, and tolerability were not reported. Follow-up duration and absolute event numbers were also not reported. Funding sources and conflicts of interest were not disclosed.
In practice, these findings suggest that intraoperative positioning strategies during RIRS may be associated with improved stone-free rates, but the evidence is constrained by methodological limitations. Clinicians should interpret the results with caution, particularly given the lack of direct intrarenal pressure monitoring and limited data on reintervention.
How this fits prior evidence
This meta-analysis extends prior coverage of surgical strategies for renal calculi. Previous findings showed that flexible aspiration navigable sheaths increase 30-day stone-free rates for stones under 2 cm, and that intelligent pressure-control ureteral sheaths improve outcomes in infection-related stone surgery. It also contrasts with a meta-analysis of RCTs showing mPCNL yields higher single-session stone-free rates than RIRS for medium stones, as the current analysis focuses on positioning within RIRS rather than comparing RIRS to mPCNL. The signal toward improved stone-free rates with positioning aligns with the broader theme that intraoperative technique modifications can influence outcomes, though the limitations noted here differ from those in prior reports.
Researchers analyzed data from 998 patients undergoing retrograde intrarenal surgery (RIRS) to treat kidney stones. The study compared different intraoperative positioning strategies against the standard lithotomy position. The primary goal was to see if changing how a patient is positioned during surgery affects the success of removing stones.
The analysis found that patients who underwent surgery with specific positioning strategies had a significantly higher stone-free rate than those in the standard position. However, other factors like the time the surgery took, the length of the hospital stay, and the rate of fever after surgery did not show significant differences between the two groups.
Because this was a meta-analysis, the results are based on a collection of different studies. Some limitations exist, such as a lack of data on reintervention rates and the absence of direct pressure monitoring during the procedure. While the results suggest that positioning may improve outcomes, the evidence is not yet conclusive enough to change standard practices for everyone.
What this means for you:
Specific positioning during kidney stone surgery may improve stone-free rates, but more data is needed.
Common questions
Does the way a patient is positioned during surgery affect kidney stone removal?
The study found that specific intraoperative positioning strategies significantly increased the stone-free rate compared to the standard lithotomy position. This suggests that how a patient is positioned during RIRS surgery may improve the success of removing kidney stones.
Are there any risks or side effects to different positioning during surgery?
The study looked at postoperative fever as a safety measure. It found that there was no significant difference in the rate of postoperative fever between patients who used special positioning and those who used the standard lithotomy position.
Does the positioning change how long a patient stays in the hospital?
The study did not find a significant difference in operative time or hospital stay between the different positioning groups. These factors did not vary significantly between the two types of surgical setups.
PURPOSE: To evaluate whether intraoperative patient positioning strategies improve stone-free outcomes and safety compared with standard lithotomy during retrograde intrarenal surgery (RIRS) for renal calculi.
METHODS: PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang, and SinoMed were searched from inception to December 2025. Comparative studies of intraoperative positioning strategies versus standard lithotomy during RIRS were included. Risk ratios (RRs) and mean differences (MDs) with 95% confidence intervals (CIs) were calculated using random-effects models where quantitative synthesis was appropriate. Subgroup analysis by stone location and exploratory sensitivity analyses according to dominant gravitational axis and CT-based outcome assessment were performed.
RESULTS: Eight studies involving 998 patients were included. Positioning strategies significantly increased the stone-free rate compared with standard lithotomy (RR 1.20, 95% CI 1.12-1.28; P < 0.001). Benefits were consistent in mixed intrarenal calculi and lower pole stones, and CT-based sensitivity analyses yielded comparable estimates. Postoperative fever did not differ significantly between groups (RR 1.15, 95% CI 0.53-2.53; P = 0.720). Operative-time and hospital-stay outcomes showed extreme heterogeneity or single-study dependency, and reintervention data were too limited for definitive conclusions.
CONCLUSION: Intraoperative positioning strategies during RIRS may improve stone-free outcomes. However, endpoint variability, exploratory subgroup classification, limited reintervention data, and the absence of direct intrarenal pressure monitoring warrant cautious interpretation. Standardized trials with CT-based endpoints, clearly defined positioning protocols, and intrarenal pressure monitoring are needed.
