{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T06:55:29Z","timestamp":1790751329037,"version":"4.1.0"},"reference-count":13,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T00:00:00Z","timestamp":1790726400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Surg."],"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To evaluate the impact of a novel \u201cstepped\u201d flexible vacuum-assisted ureteral access sheath (SFV-UAS) on stone clearance efficiency during flexible ureteroscopy lithotripsy (f-URL).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Human upper urinary tract stone fragments (&amp;lt; 4\u2005mm) were placed into\n                      <jats:italic>ex vivo<\/jats:italic>\n                      porcine renal pelves. We simulated f-URL stone extraction under continuous irrigation and vacuum suction, comparing the SFV-UAS (ureteral segment 12\/14 Fr, cystourethral segment 16\/18 Fr) with a conventional flexible vacuum-assisted ureteral access sheath (FV-UAS)(12\/14 Fr). With intrarenal pressure strictly controlled (&amp;lt; 30 mmHg) and constant vacuum suction (01 step), irrigation flow rates were evaluated at 40\u2005mL\/min, 50\u2005mL\/min, 60\u2005mL\/min, 70\u2005mL\/min, 80\u2005mL\/min, and 90\u2005mL\/min. Stone evacuation times were recorded.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      (1) Sheath type and irrigation flow rate exhibited significant main effects on clearance time [F(1,408)\u2009=\u2009189.231,\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;lt;\u20090.01, effect size 31.7%; and F(5,408)\u2009=\u200938.721,\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;lt;\u20090.01, effect size 32.2%, respectively]. A significant two-way interaction was also observed [F(5,408)\u2009=\u20098.372,\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;lt;\u20090.01, effect size 9.3%]. (2) Simple main effects revealed: First, across all corresponding irrigation rates, the SFV-UAS group achieved significantly shorter clearance times than the FV-UAS group (mean differences: MD\u2009=\u2009\u221221.598, \u221218.099, \u22128.172, \u221211.129, \u22129.762, \u22124.883; all\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;lt;\u20090.05). Second, within the SFV-UAS group, rates\u2009\u2265\u200970\u2005mL\/min resulted in significantly shorter clearance times vs. the 40\u2005mL\/min baseline (mean differences:MD\u2009=\u2009\u22129.393, \u22129.771, \u22129.084; all\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;lt;\u20090.05). Although comparisons between 60\u2005mL\/min and higher rates were non-significant, 70\u2005mL\/min was the lowest evaluated irrigation rate that demonstrated a statistically significant reduction in clearance time compared to the 40\u2005mL\/min baseline. Third, within the FV-UAS group, clearance times at\u2009\u2265\u200960\u2005mL\/min were significantly shorter than at 40 and 50\u2005mL\/min (mean differences:MD\u2009=\u2009\u221219.664, \u221212.370; all\n                      <jats:italic>P<\/jats:italic>\n                      \u2009&amp;lt;\u20090.001), with no significant differences among the\u2009\u2265\u200960\u2005mL\/min groups, indicating its plateau at\u2009\u2265\u200960\u2005mL\/min.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      Within the parameters of this\n                      <jats:italic>ex vivo<\/jats:italic>\n                      model,the SFV-UAS significantly reduces the measured stone clearance time during f-URL compared to the FV-UAS under identical irrigation conditions. For the SFV-UAS group, targeting an irrigation flow rate of\u2009\u2265\u200970\u2005mL\/min consistently optimizes stone extraction efficiency relative to baseline conditions.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fsurg.2026.1959554","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T06:01:45Z","timestamp":1790748105000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["A \u201cstepped\u201d flexible vacuum-assisted ureteral access sheath improves stone clearance efficiency: experimental results from an ex vivo porcine model"],"prefix":"10.3389","volume":"13","author":[{"given":"Daibing","family":"Lv","sequence":"first","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ming","family":"Jin","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xi","family":"Meng","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weizhong","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shanfang","family":"Yuan","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Ding","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weixi","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianghua","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoxing","family":"Liao","sequence":"additional","affiliation":[{"name":"Department of Urology, Beijing University of Chinese Medicine Third Affiliated Hospital","place":["Beijing, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"2493","DOI":"10.3390\/jcm13092493","article-title":"Retrograde intrarenal surgery for lithiasis using suctioning devices: a shift in paradigm?","volume":"13","author":"Geavlete","year":"2024","journal-title":"J Clin Med"},{"key":"B2","doi-asserted-by":"publisher","first-page":"1143","DOI":"10.1089\/end.2022.0004","article-title":"Novel flexible vacuum-assisted ureteral access sheath can actively control intrarenal pressure and obtain a complete stone-free status","volume":"36","author":"Chen","year":"2022","journal-title":"J Endourol"},{"key":"B3","doi-asserted-by":"publisher","first-page":"127","DOI":"10.1186\/s12894-025-01817-4","article-title":"Flexible and navigable suction ureteral access sheath versus traditional ureteral access sheath for flexible ureteroscopy in renal and proximal ureteral stones: a meta-analysis of efficacy and safety","volume":"25","author":"Liu","year":"2025","journal-title":"BMC Urol"},{"key":"B4","doi-asserted-by":"publisher","first-page":"372","DOI":"10.1159\/000542944","article-title":"Flexible vacuum-assisted ureteral access sheath for treating impacted ureteral stones","volume":"109","author":"Chen","year":"2025","journal-title":"Urol Int"},{"key":"B5","doi-asserted-by":"publisher","first-page":"331","DOI":"10.1007\/s00345-024-05036-8","article-title":"Fluid absorption during flexible ureteroscopy with intelligent control of renal pelvic pressure: a randomized controlled trial","volume":"42","author":"Deng","year":"2024","journal-title":"World J Urol"},{"key":"B6","doi-asserted-by":"publisher","first-page":"136","DOI":"10.23736\/S2724-6051.24.05814-2","article-title":"Comparative efficacy and safety of intelligent pressure-controlled versus flexible vacuum-assisted ureteral access sheath for 2\u20134\u2005cm renal calculi","volume":"78","author":"HUANG","year":"2026","journal-title":"Minerva Urol Nephrol"},{"key":"B7","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1007\/s00240-025-01699-z","article-title":"Comparison of flexible vacuum-assisted ureteral access sheath versus conventional sheath combined with single-use flexible ureteroscope in the treatment of renal calculi","volume":"53","author":"Xu","year":"2025","journal-title":"Urolithiasis"},{"key":"B8","doi-asserted-by":"publisher","first-page":"135","DOI":"10.1089\/end.2024.0283","article-title":"A feasibility study on the efficacy and safety of a novel tip-flexible suction ureteral access sheath combined with flexible ureteroscopic lithotripsy for treating kidney stones \u226530\u2005mm","volume":"39","author":"Chen","year":"2025","journal-title":"J Endourol"},{"key":"B9","doi-asserted-by":"publisher","first-page":"45","DOI":"10.1016\/j.eururo.2025.06.001","article-title":"Flexible ureteroscopy with a flexible and navigable suction ureteral access sheath versus mini-percutaneous nephrolithotomy for treatment of 2\u20133\u2005cm renal stones: an international, multicenter, randomized, noninferiority trial","volume":"89","author":"Zeng","year":"2026","journal-title":"Eur Urol"},{"key":"B10","doi-asserted-by":"publisher","first-page":"1013","DOI":"10.1089\/end.2021.0751","article-title":"The impact of ureteral access sheath size on perioperative parameters and postoperative ureteral stricture in retrograde intrarenal surgery","volume":"36","author":"Aykanat","year":"2022","journal-title":"J Endourol"},{"key":"B11","doi-asserted-by":"publisher","first-page":"102","DOI":"10.1007\/s00240-025-01773-6","article-title":"Optimizing aspiration efficiency in RIRS: the impact of ratio of endoscope-sheath diameter, irrigation flow, and negative pressure in an vitro study","volume":"53","author":"Ding","year":"2025","journal-title":"Urolithiasis"},{"key":"B12","volume-title":"Munson, Young and Okiishi\u2019s Fundamentals of Fluid mechanics","author":"Gerhart","year":"2016"},{"key":"B13","doi-asserted-by":"publisher","first-page":"304","DOI":"10.4103\/UA.UA_181_20","article-title":"Fluoroscopy-free semirigid ureteroscopy for ureteral stone treatment: a prospective single-arm study of feasibility, efficacy, and safety","volume":"15","author":"Aliaga","year":"2023","journal-title":"Urol Ann"}],"container-title":["Frontiers in Surgery"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fsurg.2026.1959554\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T06:01:45Z","timestamp":1790748105000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fsurg.2026.1959554\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,30]]},"references-count":13,"alternative-id":["10.3389\/fsurg.2026.1959554"],"URL":"https:\/\/doi.org\/10.3389\/fsurg.2026.1959554","relation":{},"ISSN":["2296-875X"],"issn-type":[{"value":"2296-875X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,30]]},"article-number":"1959554"}}