Double-Sheath Vacuum Suction Minimally Invasive Percutaneous Nephrolithotomy for Management of Large Renal Stones

This study aimed to describe a novel double-sheath vacuum suction minimally invasive percutaneous nephrolithotomy (mini-PCNL) to overcome the deficiencies of the conventional procedure.Between March 2019 and December 2019, 65 patients (37 males and 28 females) with a mean age of 41 years (range 23-69) underwent mini-PCNL with double-sheath vacuum suction. It consisted of an F20 Y-shaped sheath as an outer sheath and an F16 Y-shaped sheath as an inner sheath, in which the inner sheath was longer than the outer sheath. The oblique arm of the outer sheath and the inner sheath was connected to the perfusion inflow and the vacuum suction, respectively. A 550-μm holmium-YAG laser was introduced for stone fragmentation through the working channel of the mini-nephroscope, which was no longer connected to the perfusion fluid.All procedures were successful. Mean operation time was 50.2 min (range 39-83). Mean hemoglobin decrease was 5.2 g/L (range 1.0-15.5), and no patient needed a blood transfusion. One patient (1.5%) with low fever (<38°C) at day 1 had returned to normal at day 2 without administration of antibiotics. There were no Clavien grade 2-4 complications. Mean postoperative hospital stay was 2.4 days (range 2-6). The initial stone-free rate of PCNL was 81.53% (53 of 65 patients). One month after surgery, the final stone-free rate increased to 90.77% (59/65 patients).The double-sheath vacuum suction mini-PCNL is a safe and effective modality for large renal stones, which might increase the efficiency of stone extraction with low intrapelvic pressure.