Comparative study of the treatment of 20–30 mm renal stones with miniaturized percutaneous nephrolithotomy and flexible ureterorenoscopy in obese patients
To evaluate and compare flexible ureteroscopy (f-URS) and mini-percutaneous nephrolithotomy (mPNL) for 20–30 mm renal stones in obese patients regarding efficacy and safety.
Between May 2011 and June 2017, 254 obese patients who had 20–30 mm kidney stone were consecutively included in the study; 106 patients underwent mPNL and 148 underwent f-URS by the same surgeon. The following parameters were retrospectively assessed: patient and stone characteristics, surgical details, perioperative outcomes, and stone-free rates (SFR).
F-URS group was similar to mPNL group in terms of the mean duration of surgery (92.8 ± 26.1 vs 87.4 ± 31.5 min, P = 0.137) and the final SFR (89.1 vs 92.5%, P = 0.381). The f-URS group had significantly shorter postoperative stay (1.0 ± 0.8 vs 4.3 ± 1.7 days, P < 0.001) and lower postoperative complications (11.5 vs 26.4%, P = 0.002). However, the f-URS group had a lower SFR after first session (67.2 vs 87.4%, P < 0.001) and needed more number of procedures (1.5 ± 0.4 vs 1.3 ± 0.4, P < 0.001) than the mPNL group.
MPNL has a higher efficacy (higher SFR after first session and lower number of procedures); however, f-URS offers advantages regarding safety (lower complication rate). Therefore, both options can be offered to obese patients with renal stones from 20 to 30 mm in size. Nevertheless, these results must be confirmed by further prospective randomized trials.
KeywordsMPNL F-URS Renal stones Obese Size
European Association of Urology
Kidney ureter and bladder X-ray
Ureteral access sheath
Body Mass Index
American Society of Anesthesiologists
We thank Hugh McGonigle, from Liwen Bianji, Edanz Group China, for editing the English text of a draft of this manuscript.
HQC: Project development, data collection and management, data analysis, manuscript writing/editing. ZYC: Project development, data collection, manuscript editing. FZ: Data collection and management, manuscript editing. YL: Data collection, manuscript editing. ZQY: Data collection, manuscript editing. CH: Project development, data collection, manuscript editing. YH: Project development, data collection and management, data analysis, manuscript writing/editing.
Funding was provided by the National Natural Science Foundation of China 81770705 (to HQ Chen) and the National Natural Science Foundation of China 81700663 (to Yao He).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
Informed consent was obtained preoperatively from all of our patients included in our study.