How do we choose the optimal length of flexible and navigable suction ureteral access sheaths (FANS): an EAU endourology and AUSET prospective multicenter analysis
Year: 2026
Type: article
Study design: Observational Study
Abstract: PURPOSE: To evaluate how to assess the optimal length of flexible and navigable suction ureteral access sheaths (FANS) to be used during flexible ureteroscopy (FURS) for kidney stones. METHODS: A prospective multicenter study (16 centers, July 2024–January 2025) enrolled 226 adults with normal renal anatomy undergoing FURS with FANS for renal stones. Three preoperative measurements were analyzed: (1) Subjective on X-ray: T12–pubic symphysis, (2) Objective on CT: upper pole–pubic symphysis, and (3) Dynamic ureteral catheter length with retrograde pyelogram (RPG): upper pole–urethral meatus. Sheath length appropriateness (too short/correct/too long) was assessed intraoperatively using predefined criteria (complete calyceal access, ergonomics, need for ancillary techniques). Secondary outcomes included 30-day stone-free rates (SFR) and complications. RESULTS: Sheath length was deemed correct in 63.7%, too short in 9.7%, and too long in 26.5% of cases. For both genders, dynamic measurement of ureteric catheter length from upper pole calyx to 5 cm beyond the urethral meatus demonstrated the strongest correlation with optimal length (R = 0.7). Gender-specific formulas for optimal FANS length were derived: Male: 0.52 × ureteral catheter length + 26 cm. Female: 1.2 × ureteral catheter length − 2.1 cm. Compensatory techniques for length discrepancies included assistant-held stabilization of FANS (28.3%) and telescoping of penis (3.5%). 96% of sheaths accessed all calyces. The 30-day SFR was 92.5% (Grade A: 79.2% zero fragments; Grade B: 13.3% fragments ≤ 2 mm). Complications were low: sepsis not requiring ICU admission (0.4%) and ureteric stricture (0.6%). Only 2.7% patients were planned for reintervention. CONCLUSION: The selection of an optimal FANS length is critical for optimizing outcomes in FURS. Dynamic RPG-ureteral catheter length measurement best predicts this, enabling gender-specific formulas for easy estimation. Our results provide valuable insights into the clinical relevance of preoperative measurements, intraoperative adjustments, and the impact of sheath length on procedural success and complications.
Source: World Journal of Urology
Authors: Steffi Kar Kei Yuen, Daniele Castellani, Albert El Hajj, Bokye Soebhali, Deepak Ragoori, Khi Yung Fong, Chu Ann Chai, Chinnakhet Ketsuwan, Geavlete Petrisor, Mehmet Ilker Gokce, Karl Tan, Jia-Lun Kwok, Yi Quan Tan, Kremena Petkova, Palaniappan Sundaram, Lazaros Tzelves, Yadong Lu, Vigen Malkhasyan, Nariman Gadzhiev, Wissam Kamal, Luis Rico, Pablo Conteras, Giacomo Maria Pirola, Bhaskar Somani, Vineet Gauhar
Institutions: Chinese University of Hong Kong, European Association of Urology, Azienda Ospedaliero-Universitaria delle Marche, American University of Beirut Medical Center, American University of Beirut, Mulawarman University, Singapore General Hospital, University of Malaya, Mahidol University, Ramathibodi Hospital, Carol Davila University of Medicine and Pharmacy, Clinical Emergency Hospital Bucharest, Spitalul Clinic de Urgenta Sfantul Ioan, Ankara University, Veterans Memorial Medical Center, Tan Tock Seng Hospital, Ng Teng Fong General Hospital, National University Hospital, National University Health System, Military Medical Academy, Sengkang General Hospital, National and Kapodistrian University of Athens, Sismanoglio General Hospital, National Cancer Centre Singapore, Botkin Hospital, St Petersburg University, King Fahad Hospital Jeddah, Hospital Alemán, MultiMedica, Ospedale San Giuseppe, University Hospital Southampton NHS Foundation Trust
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,390
OpenAlex ID: W7124829548