Assessing flexible ureteroscopy outcomes for lower Pole versus non lower Pole stones using the flexible and navigable suction ureteric access sheath: a prospective multicenter study by EAU Endourology and PEARLS group.

Purpose: Use of suction in flexible ureteroscopy is increasing lately. The introduction of flexible and navigable suction access sheath (FANS) has shown improved stone free rate (SFR). However, its efficacy in lower pole stone (LPS) in terms of SFR and complications is yet to be studied.

Methods: We collected data from 25 centers that included 394 adult patients undergoing ureteroscopy using FANS. Non contrast CT (NCCT) scan was done within first 30 days post operatively to access the SFR. Residual fragments were graded as A: 100% SFR; B: single fragment ≤ 2 mm; C: single fragment 2.1-4 mm; D: Single or multiple fragments > 4 mm. Post operative complications were recorded.

Results: Out of 394 patients, non LPS (group1) comprised of 268 patients, rest 126 patients had LPS (group 2). Single stage zero fragment SFR was seen in 58.6% (group 1) vs. 54.8% (group 2) (P = 0.619). Single stage grade A + B SFR was achieved in 96.6% vs. 98.4% in groups 1 and 2 respectively. On multivariate analysis Thulium fiber laser use was significantly associated with higher odds of being grade A stone-free, while stone volume with lower odds. In LPS group only two patients needed reintervention. The highest grade of complication was Clavien 2, which was seen in 3.2% LPS group.

Conclusion: Use of flexible and navigable suction ureteric access sheath for lower pole stones is effective and safe. The stone free rate of lower pole stones is comparable to non-lower pole locations with very low reintervention rate in both groups.