Sex Disparity in fURL with FANS-UAS for 2-3 cm UUTS: Shorter Operative Time in Female Patients.

BACKGROUND

The flexible and navigable suction ureteral access sheath (FANS-UAS) has expanded the indications for flexible ureteroscopic lithotripsy (fURL) to include 2-3 cm upper urinary tract stones (UUTS). However, the impact of patient sex on surgical efficiency with this novel technique remains unknown.

PATIENTS AND

METHODS

This single-center retrospective study enrolled 318 consecutive patients (210 males, 108 females) who underwent fURL with FANS-UAS for solitary 2-3 cm UUTS between December 2024 and May 2026. Exclusion criteria included anatomical abnormalities and severe organ dysfunction. Baseline parameters, operative time (total and by phase), stonefree rates (SFRs) on postoperative day (POD) 1 and POD 30, and ClavienDindo complications were compared between sexes. Three general linear models (GLM) were constructed to adjust for age, stone size, hydronephrosis, and other confounders, and to dissect the effect of sex on total operative time, fragmentation time, and fragment retrieval time.

RESULTS

Total operative time was significantly shorter in females than in males (63.4±15.0 vs. 79.9±21.4 min, p<0.01), driven predominantly by a marked reduction in fragment retrieval time (36.5±10.4 vs. 50.9±13.5 min, p<0.01), whereas fragmentation time did not differ significantly (17.8±5.7 vs. 18.4±5.9 min, p=0.341). Immediate SFR (86.1% vs. 87.6%, p=0.704) and followup SFR at POD 30 (91.7% vs. 90.0%, p=0.831) were comparable, as were overall complication rates. GLM analysis confirmed female sex as the strongest independent predictor of shorter total operative time (B=-18.5, 95% CI: -21.6 to -15.4, F=134.9, p<0.01) and fragment retrieval time (B=-15.6, 95% CI: -17.8 to -13.4, F=191.1, p<0.01).

CONCLUSION

Female patients undergoing fURL with FANSUAS for 2-3 cm UUTS have significantly shorter operative times than male. Patient sex should be considered in preoperative counseling and surgical planning.