The safety and efficacy of mini-percutaneous nephrolithotomy vs. retrograde intrarenal surgery for treatment of renal lithiasis in pelvic ectopic kidney: an exploratory pilot study

BACKGROUND: To compare the safety and efficacy of mini-percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for the treatment of renal lithiasis in patients with pelvic ectopic kidney. METHODS: From January 2015 to October 2017, mini-PCNL and RIRS were performed in ten patients diagnosed with lithiasis in pelvic ectopic kidneys, including three cases under laparoscopy-assisted mini-PCNL. Patient demographics and perioperative characteristics (age, gender, BMI, side of pelvic kidney, stone size, stone number, stone location, special medical history, and ASA physical status classification), and operative and post-operative related details (operation time, hospital stay, blood loss, VAS, analgesic requirement, complications, and stone free outcome) were reviewed. RESULTS: Although the mean operation time of mini-PCNL (71.3 min) was shorter than RIRS (85.3 min), the mean operation time of laparoscopy assisted mini-PCNL (92 min) was longer than patients without laparoscopy-assisted mini-PCNL (55.8 min). However, the use of mini-PCNL allowed for larger lithiasis to be dealt with (1.9 cm in laparoscopy assisted mini-PCNL and 2.4 cm in mini-PCNL without laparoscopy-assist) compared with RIRS (1.2 cm). In addition, although the mean hospital-stay time, blood loss, and analgesic requirement of patients undergoing RIRS were less than those receiving mini-PCNL, the success rate of RIRS was only 50% (3/6) in comparison to 100% (7/7) for mini-PCNL. Except for pain and urinary tract infection after the operation, there were no significant intraoperative and postoperative complications, and no residual lithiasis were seen in any patient. CONCLUSIONS: Although RIRS was less time-consuming and invasive, mini-PCNL can deal with the bigger lithiasis and more complex situations with a higher success rate. Both mini-PCNL and RIRS are feasible and safe treatments for pelvic ectopic kidney lithiasis with each carrying unique advantages. Hence in practice, an appropriate individualized treatment should be selected depending on patient characteristics.