Middle calyx access is better for single renal pelvic stone in ultrasound-guided percutaneous nephrolithotomy.

To compare the outcomes among upper calyx, middle calyx, and lower calyx access in complete ultrasound-guided percutaneous nephrolithotomy (PCNL) for single renal pelvic stone. Between July 2014 and September 2015, the data of 153 patients with single renal pelvic calculi were retrospectively reviewed in this study and patients were divided to group 1 (45 patients, upper calyx access), group 2 (57 patients, middle calyx access), and group 3 (51 patients, lower calyx access). Preoperative characteristics and intraoperative and postoperative parameters were analyzed and compared. A p value of <0.05 was considered significant. Important patient- and stone-related parameters were similar among the three groups. The mean operative time was significantly shorter in the middle calyx group than the lower and upper calyx groups (41.2 ± 6.9 vs. 50.2 ± 9.3 and 46.0 ± 9.6 min, respectively). The middle calyx group had a higher stone-free rate than the lower and upper calyx groups (98.20 vs. 84.3 % and 93.3 %, respectively, p = 0.037). There were no significant differences in mean postoperative hemoglobin decrease and incidence of complications among groups (p = 0.42 and 0.862, respectively). Middle calyx access achieved superior outcomes for removal of single renal pelvic stone via ultrasound-guided PCNL.