Zero-fragment Nephrolithotomy: A Multi-center Evaluation of Robotic Pyelolithotomy and Nephrolithotomy for Treating Renal Stones.

BACKGROUND: Robotic pyelolithotomy (RPL) and robotic nephrolithotomy (RNL) may be utilized for treating kidney stones as an alternative to percutaneous nephrolithotomy or flexible ureteroscopy.

OBJECTIVE: To describe the techniques of RPL and RNL, and present multi-center outcome data for patients undergoing these procedures.

DESIGN, SETTING, AND PARTICIPANTS: This study was a retrospective analysis of 27 patients undergoing RPL and RNL at five tertiary academic institutions between 2008 and 2014.

SURGICAL PROCEDURE: RPL and RNL without use of renal ischemia.

MEASUREMENTS: We assessed stone clearance by visual assessment and postoperative imaging. We also examined other factors, including complications (Clavien grade), estimated blood loss, operative time, and length of stay.

RESULTS AND LIMITATIONS: Twenty-seven patients underwent 28 procedures for a mean renal stone size of 2.74cm (standard deviation: 1.4, range: 0.8-5.8). The mean stone volume was 10.2cm3 . RPL accounted for 26 of these procedures. RNL was performed in one patient, while another underwent combined RPL-RNL. Indications included failed previous endourological management (13), staghorn calculi (five), gas containing stone (one), calyceal diverticulum (one), complex urinary tract reconstruction (two), and patient preference (four). The mean patient age was 35.6 yr and mean body mass index was 25.5kg/m2 . Mean operative time/console times were 182min and 128min, respectively. The mean estimated blood loss was 38ml. The mean length of stay was 1.7 d. There was no significant change in preoperative and postoperative serum creatinine levels. The overall complication rate was 18.5% (Clavien 1=3.7%; 2=7.4%; 3b=7.4%). The complete stone-free rate was 96%.

CONCLUSIONS: RPL and RNL are safe and reasonable options for removing renal stones in select patients. In particular, RPL allows the removal of stones without transgressing the parenchyma, reducing potential bleeding and nephron loss.

PATIENT SUMMARY: The robotic approach allows for complete removal of the renal stone without fragmentation, thereby maximizing chances for complete stone clearance in one procedure.