To evaluate the characteristics and application value of "rigid and flexible precision puncture" in ultrasound-guided percutaneous nephrolithotripsy.

A total of 352 patients who underwent percutaneous nephrolithotripsy in the Department of Urology, Wuhan Puren Hospital between December 2013 and December 2015 were analyzed retrospectively. Their pelvis, renal calyx structure and distribution of calculi were identified using three-dimensional reconstruction of CT and abdominal plain film (KUB) examination before operation, and verified using preoperative routine ultrasound, so as to design the best puncture path. During operation,"rigid and flexible precision puncture" was performed under the guidance of ultrasound, and 16 ~ 20 F channels were established; 12.5 F minimally invasive nephroscope was used, and pneumatic lithotripsy combined with 60 W holmium laser lithotripsy was used in the cavity. Before the end of operation, residual calculi were verified using ultrasound; acupuncture assisted or multi-channel calculi extraction should be performed in the case of obvious residual calculiat parallel calyx. The patients aged from 21~80 years, with an average age of (44±10) years old. There were 79 cases of solitary calculi, 212 cases of unilateral multiple calculi and61 cases of staghorn calculi, with a diameter of 1.6~5.7 cm and an average of (2.4±0.5) cm.

For the 352 patients, precision puncture was performed to predeter mine target calyceal fornix successfully, and satisfactory channels were established. One patient presented pyonephrosis; only renal stoma catheter was indwelled for phase II nephrolithotripsy.Sixteen patients underwent phase I dual-channel nephrolithotripsy, and 7 patients underwent phase I primary channel nephrolithotripsy. Success rate of the first ultrasound-guided puncture was up to 97.7% (344/352), and that of the second puncture reached 100%.The length of puncture was 1.0 ~ 3.0 min, with an average of (1.1±0.4) min; the channel establishment time was 2.0 ~ 5.0 min, with an average of (3.1±1.0) min, and the length of operation was 10~80 min, with an average of (32±12) min.No postoperative complications such as pneumothorax, liver, spleen and intestinal canal injury occurred.Three patients (0.85%) received blood transfusion, and 2 patients (0.57%) presented postoperative delayed bleeding, all of who recovered after treated with bed rest and high-protein diet for 1 week. KUB plain film was performed on 3~4 d after operation, and the calculi clearance rate in phase I was: 100% (79/79) for solitary calculi, 91.5% (194/212) for multiple calculi and 81.9% (50/61) for staghorn calculi, with an overall clearance rate of 91.8% (323/352).

The ultrasound-guided "rigid and flexible precision puncture" can achieve precision punctureduring operation, and it is worthy of clinical application.