Table 2: Intraoperative and postoperative parameters.

Immediate stone-free rate (after 1 day)88.9% (32/36)
Total stone-free rate (after 1 month)97.2% (35/36)
Hospital stay (day)3.0 ± 0.9 (2–5)
No. Double-J stent (%)4 (11.1%)
Operative time (min)59.8 ± 15.9 (30–90)
Hemoglobin drop (g/L)5.4 ± 7.8 (0–21)
Second-look UMP1 (2.8%)
No. of tract size 13Fr/11Fr31 (86.1%)/5 (13.9%)
No. of puncture locations
 Upper/middle/lower pole calyces7 (19.4%)/15 (41.7%)/
14 (38.9%)
 Supracostal/infracostal 15 (41.7%)/21 (58.3%)
 Posterior/anterior calyx30 (83.3%)/6 (16.7%)
Significant complication6 (16.7%)
 Urosepsis2 (5.6%)
 Urinary extravasations1 (2.8%)
 Fever (>38.5°C)3 (8.3%)
Stone analysis
 Calcium oxalate and/or phosphate18 (50%)
 Struvite1 (2.8%)
 Uric acid4 (11.1%)
 Mix stones13 (36.1%)