Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2025 Nov 28;15(1):42780.
doi: 10.1038/s41598-025-26987-x.

RIRS with flexible vacuum-assisted ureteral access sheath for large renal stones: a prospective randomized controlled study

Ye-Fei Ding  1 , Tao Lin  1 , Yan Cheng  1 , Guan-Li Huang  1 , Yun-Bo Ma  2
Affiliations
Randomized Controlled Trial

RIRS with flexible vacuum-assisted ureteral access sheath for large renal stones: a prospective randomized controlled study

Ye-Fei Ding et al. Sci Rep. .

Abstract

To observe the efficacy and safety of retrograde intrarenal surgery (RIRS) combined with a flexible vacuum-assisted ureteral access sheath (FV-UAS) in patients with large renal stones (LRS). A total of 149 patients with LRS were prospectively randomized into two groups: 75 in the FV-UAS group and 74 in the minimally invasive percutaneous nephrolithotomy (MPCNL) group. The primary outcome was the stone-free rates (SFRs) on the first postoperative day. Secondary endpoints included the total SFRs 1 month postoperatively, lithotripsy time, hemoglobin reduction, length of postoperative hospital stay, quality of life (QoL) score improvement, incidence of ureteral stricture at 3 months postoperatively, and any surgery-related complications. Patient demographics and preoperative clinical characteristics showed no apparent difference between the two groups (all P > 0.05). Postoperative data revealed a significantly longer lithotripsy time in the FV-UAS group than the MPCNL group (113.1 vs. 82.5 min, P < 0.001). The mean decrease in hemoglobin was significantly lower in the FV-UAS group than in the MPCNL group (8.2 vs. 17.7 g/L, P < 0.001). Similarly, the average hospital stay was shorter in the FV-UAS group than the MPCNL group (1.7 vs. 5.1 d, P < 0.001). Meanwhile, SFRs on the first postoperative day and 1 month postoperatively were statistically similar between the two groups (P > 0.05). QoL improvement was significantly higher in the FV-UAS group than in the MPCNL group (33.4 vs. 26.9, P < 0.001). The difference in ureteral stricture at 3 months postoperatively was not statistically significant (P > 0.05). Notably, the overall rate of postoperative complications was markedly lower in the FV-UAS group than in the MPCNL group (P < 0.05). Our study showed the safety and feasibility of applying RIRS combined with FV-UAS for LRS treatment, providing advantages such as high SFRs, minimal trauma, fast recovery, and low incidence of postoperative complications. It can be used as a clinical treatment alternative for LRS. The protocol for this study has been accepted by the Chinese Clinical Trial Registry (Ethics approval number: ChiCTR2200056402; Date of registration: 02-05-2022).

Keywords: Flexible vacuum-assisted ureteral access sheath; Large renal stone; Minimally invasive percutaneous nephrolithotomy; Retrograde intrarenal surgery; Stone-free rates.

PubMed Disclaimer

Conflict of interest statement

Declarations. Competing interests: The authors declare no competing interests. Ethical approval: All procedures performed in studies involving human participants were in accordance with the ethical standards of Liaocheng People’s Hospital (ethics approval number: 2022–11313) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The clinical trial registration number for study is ChiCTR2200056402. Informed consent: Informed consent was obtained from all individual participants included in the study.

Figures

Fig. 1
Fig. 1
Flowchart for cases selection of the trial outlining enrollment, randomisation, allocation, follow-up, and analysis according to intention-to-treat standards. RIRS, Retrograde intrarenal surgery; FV-UAS, Flexible vacuum-assisted ureteral access sheath; MPCNL, minimally invasive percutaneous nephrolithotomy.
Fig. 2
Fig. 2
Structural diagrams of the flexible vacuum-assisted ureteral access sheath (FV-UAS).
Fig. 3
Fig. 3
Simulation diagrams of flexible ureteroscope (fURS) combined with the flexible vacuum-assisted ureteral access sheath (FV-UAS) for the treatment of large renal stones (LRS).
See this image and copyright information in PMC

References

    1. American Urological Association. Medical Management of Kidney Stones: AUA Guideline. https://www.auanet.org/guidelines-and-quality/guidelines/kidney-stones-m... (2019).
    1. European Association of Urology. EAU Guidelines on Urolithiasis. https://uroweb.org/guidelines/urolithiasis (2024).
    1. Assimos, D. et al. Surgical management of stones: American urological Association/Endourological society Guideline, PART II. J. Urol.196 (4), 1161–1169. 10.1016/j.juro.2016.05.091 (2016). - DOI - PubMed
    1. Soderberg, L. et al. Percutaneous nephrolithotomy versus retrograde intrarenal surgery for treatment of renal stones in adults. Cochrane Database Syst. Rev.11 (11), CD013445. 10.1002/14651858.CD013445 (2023). - DOI - PMC - PubMed
    1. Lai, S. et al. Comparing different kidney stone scoring systems for predicting percutaneous nephrolithotomy outcomes: A multicenter retrospective cohort study. Int. J. Surg.81, 55–60. 10.1016/j.ijsu.2020.07.025 (2020). - DOI - PubMed

Publication types

LinkOut - more resources