External Physical Vibration Lithecbole After Retrograde Intrarenal Surgery Versus Micro-Percutaneous Nephrolithotomy for Lower Pole Renal Calculi of <20 mm in Size: A Prospective Study

Abstract

Percutaneous nephrolithotomy (PCNL) has been recommended as first-line therapy for larger lower calyceal stones (> 20 mm). However, PCNL causes greater surgical trauma to the patient. We introduced the use of an external physical vibration lithecbole (EPVL) after retrograde intrarenal surgery to improve the safety and stone-free rate of lower calyceal stones with less trauma and fewer adverse effects compared with micro-percutaneous nephrolithotomy (MPCNL). 123 patients with stones of < 20 mm in diameter in the lower renal calyces were randomized to undergo either flexible ureteroscopy (fURS) + EPVL (n = 62) or MPCNL (n = 61). In terms of the primary endpoints, the stone-free rate at 4 weeks was similar between the two groups (96.77% in fURS + EPVL vs. 96.67% in MPCNL), but the change in the hemoglobin level from baseline was significantly different in favor of fURS + EPVL (8.87 ± 2.80 vs. 15.72 ± 4.71 g/dL, respectively; P < 0.001). Patients in the fURS + EPVL group had a significantly lower occurrence rate of complications and lower visual analogue scale scores at 6, 12, and 48 hours after surgery. Both fURS + EPVL and MPCNL can effectively clear lower calyceal stones of < 20 mm in diameter with a relatively high stone-free rate. Advantages of fURS + EPVL over MPCNL include less severe decreases in hemoglobin, a lower occurrence rate of complications, and lower visual analogue scale scores after surgery.