Temporal Trends and Treatment Outcomes of Flexible Ureteroscopy for Lower Pole Stones in a Tertiary Referral Stone Center

Abstract

Introduction:

To evaluate trends in efficacy and safety of flexible ureteroscopy (fURS) for the treatment of lower pole stones (LPS) over a 6-year period and to compare the annual outcomes after one fURS procedure retrospectively.

Patients and Methods:

Four hundred nine patients were treated for pure LPS. An analysis of the annual outcomes regarding patient characteristics, operative parameters, stone-free rates (SFRs), and complication rates (CRs) was performed. The SFR was stratified according to stone size and number of stones per patient. Patient data are expressed as mean±standard deviation.

Results:

There were no annual differences regarding age, body–mass index, stone size (7.09±4.31 mm), number of stones per patient (1.66±2.86), operative time (52.93±33.58 minutes), use of postoperative stents (59.2%), and the Ho:YAG laser lithotripsy rate (49.4%) during the 6-year period. Total primary SFR (annual range) of 97.6% (88.2%–100%), 89.1% (82.9%–96.3%), 71% (60%–78.6%) for urinary calculi <5 mm (3.43±0.78 mm), 5–9 mm (6.69±1.34 mm), and ≥10 mm (13.09±6.02 mm) could be demonstrated over the 6-year period. The total SFR differed significantly between urinary calculi <5 mm, 5–9 mm, and those ≥10 mm (p<0.0179). The SFR (annual range) decreased from 90% (86.2%–95.4%) in patients with 1 stone to 84.1% (60%–100%) in those with ≥3 stones. Perioperative complications (annual range) occurred in 9.7% (6%–13.6%) of the patients (Clavien I 5.1% [1.2%–8.6%], Clavien II 2% [0%–4.9%], Clavien IIIa 0.9% [0%–3.4%], Clavien IIIb 1.7% [1.2%–4.8%]) without differences in the annual CR.

Conclusions:

fURS is a safe and efficacious procedure for the treatment of LPS with high primary SFR and low CR. fURS in larger LPS (≥10 mm) is associated with the risk for staged procedures.