Flexible and navigable suction ureteral access sheath (FANS) has been proven to improve stone-free rate (SFR) and many studies report high intraoperative 100% stone-free status (IO-SFS) and postoperative 100% stone-free status (PO-SFS). The reliability of IO-SFS vis-à-vis image-proven PO-SFS needs to be evaluated as it has implications on perioperative management.
Our prospective, multicenter study enrolled 704 adult patients from 21 centers who underwent FURS with FANS between August 2023 and October 2024. IO-SFS was categorized into three groups: (1) 100% SFR (no dust or fragments), (2) only dust remaining, and (3) both dust and fragments remaining. PO-SFS was assessed via 2 mm non-contrast computed tomography (NCCT) at 30 days and categorized into four grades: Grade A (100% stone-free), Grade B (single ≤ 2 mm residual fragment), Grade C (single 2.1-4 mm), and Grade D (multiple or any > 4 mm). Primary outcome was correlation between intraoperative and postoperative 100% SFS. Secondary outcomes included perioperative complications, reintervention rates, and predictors of residual fragments and perioperative complications.
IO-SFS reported 100% SFR in 395 cases. Postoperative NCCT confirmed a significantly higher SFS (Grade A + B) in this group (99%) compared to 95.8% in the dust only group and 61.1% in the dust and fragments group (p < 0.001). Positive predictive value (PPV) of intraoperative 100% SFR was 99% with post-op NCCT, while negative predictive value (NPV) was only 12.3%. Secondary outcome analysis showed higher stone volumes, lower pole locations, and use of high-power holmium lasers were associated with increased 2-4 mm residual fragments (OR 6.53, p = 0.047). In the 100% SFR group, the use of 12/14 Fr UAS and disposable scopes was significantly higher, with a preferred strategy combining fragmentation, dusting, and aspiration. No cases of sepsis or significant postoperative bleeding were reported due to the use of FANS, with fewer patients requiring post-operative stenting.
This study provides robust evidence that surgeon-reported 100% IO-SFS is highly predictive of NCCT-proven postoperative stone-free outcomes, with a PPV of 99%. However, intraoperative detection of residual fragments is less reliable in predicting persistent stone burden, as only 40% of these patients eventually achieved SFS on NCCT. Standardized imaging protocols remain necessary to optimize postoperative management and patient counseling, while avoid unnecessary re-intervention.
World journal of urology. 2025 Mar 21*** epublish ***
Vineet Gauhar, Olivier Traxer, Steffi Kar Kei Yuen, Daniele Castellani, Guohua Zeng, Khi Yung Fong, Zhu Wei, Deepak Reddy Ragoori, Mohamed Elshazly, Kremena Petkova, Wissam Kamal, Nariman Gadzhiev, Mehmet Ilker Gokce, Mohamed Amine Lakmichi, Chaeeun Lee, Albert El Hajj, Marek Zawadzki, Luis Rico, Pablo Contreras, Tzevat Tefik, Chu Ann Chai, Petrisor Geavlete, Kemal Sarica, Jia-Lun Kwok, Bhaskar Kumar Somani, Ee Jean Lim
Department of Urology, Ng Teng Fong General Hospital, Singapore, Singapore., Department of Urology, Sorbonne University, Tenon Hospital, AP-HP, Paris, France., SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong, Hong Kong, China., Urology Division, Azienda Ospedaliero-Universitaria Ospedali Riuniti di Ancona, Università Politecnica delle Marche, Ancona, Italy., Department of Urology and Guangdong Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China., Yong Loo Lin School of Medicine, National University of Singapore, 11 Hospital Dr, Singapore, 169610, Singapore., Asian Institute of Nephrology and Urology, Urology, 6-3-562/A, Errum Manzil, Hyperabad, 500082, Telangana, India., Faculty of Medicine Urology Department, Menoufia university, Shibin el Kom, Egypt., Department of Urology and Nephrology, Military Medical Academy, 3, Georgi Sofiiski blvd., Sofia, 1606, Bulgaria., Division of Urology, Department of Surgery, Ministry of the National Guard-Health Affairs, Riyadh, Saudi Arabia., Department of Urology, Saint-Petersburg State University Hospital, Saint-Petersburg, Russia., Department of Urology, Ankara University School of Medicine, Ankara, Turkey., Department of Urology, University Hospital Mohammed the VIth of Marrakesh, Marrakesh, Morocco., Division of Urology, Department of Surgery, American University of Beirut, Beirut, Lebanon., Urology Unit, St. Anna Hospital, Piaseczno, Poland., Department of Urology, Hospital Aleman, Buenos Aires, Argentina., Department of Urology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey., Urology Unit, Department of Surgery, University Malaya, Kuala Lumpur, Malaysia., Saint John Emergency Clinical Hospital, Bucharest, Romania., Department of Urology, Medical School, Biruni University, Istanbul, Turkey., Department of Urology, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore., University Hospital Southampton NHS Foundation Trust GB, Southampton, UK., Department of Urology, Singapore General Hospital, Academia Level 5, 20 College Rd, Singapore, 169856, Singapore. .