The safety and efficacy of ultrasound guided combined needle-perc and standard percutaneous nephrolithotomy in the treatment of staghorn stone

Objective To summarize our preliminary clinical experience of ultrasound-guided needle-perc combined with standard percutaneous nephrolithotomy (PCNL) in the treatment of staghorn stones, and to analyze its safety and efficacy. Methods The clinical data of 65 patients with staghorn stones treated by ultrasound-guided needle-perc combined with standard PCNL under general anesthesia with the patient in prone position from December 2017 to June 2019 were retrospectively reviewed. A total of 41 males and 24 females were included. The mean age was (53.5+ 8.9) years. The mean body mass index (BMI) was (25.1±2.9) kg/m2, and the mean stone diameter was (10.9±3.1) cm. Among them, there were 3 cases with bilateral staghorn stones, 38 cases with complete staghorn calculi, 36 cases with non- or mild preoperative hydronephrosis, 12 cases with previous ipsilateral renal surgery, and 9 cases with solitary kidneys. Ultrasound-guided renal access and tract dilation were used to establish F24 standard channel. Pneumatic combined with ultrasonic lithotripsy with suction system was used to treat staghorn stones under nephroscope. Needle-perc consists of F4.2 needle-like metal sheath connected with a three-way tube. A 0.6 mm diameter video fiber, 200 um holmium laser fiber and liquid perfusion device can be connected through the three-way tube respectively. The residual stone in the parallel calyx after standard PCNL were punctured by needle-perc under ultrasound guidance, and then the holmium laser fiber was used for lithotripsy. Results In this study, a total of 68 renal units were included. The median operative time was 79.8 minutes, ranging 45-129 minutes. The median decrease of hemoglobin on postoperative day 1 was 10.6 g/L, ranging 0-25.9 g/L. The median length of postoperative hospital stay was 5.5 days, ranging 4-7 days and the median time of tract establishment was 4.8 minutes, ranging 2.5-9.6 minutes. The median number of standard tract established was 1.5, ranging 1-3 and the median number of needle-perc punctured was 1.0, ranging 1-3. The total complication rate was 10.3% (7 cases), including 5 cases of Clavien grade Ⅰ, 2 cases of postoperative fever, 3 cases of analgesic use. There were 2 cases of Clavien grade Ⅱ. All of them were blood transfusion. The initial stone free rate was 79.4%(54/68). Of the 14 patients with residual stones, 9 patients underwent second-stage operation, 7 patients were stone free, and the final stone free rate was 89.7%(61/68). Conclusions Ultrasound-guided needle-perc combined with standard PCNL is safe and effective in the treatment of staghorn stone. Key words: Kidney calculi; Ultrasound guidance; Staghorn stone; Percutaneous nephrolithotomy; Needle-perc