Background: The establishment of tract is very important in percutaneous nephrolithotomy. At present, balloon dilatation is widely used, but ultrasound or fluoroscopy guided balloon dilatation tract can not achieve real-time monitoring of the whole process, which easily leads to failure of tract establishment. we use ultrasound combined with endoscopic technology to realize the whole process monitoring of tract establishment. The purpose is to evaluate the safety and effectiveness of the technology.Methods: Patients who underwent PCNL with only using the balloon dilator from January 2019 to April 2021 in the Second Affiliated Hospital of Anhui Medical University were retrospectively reviewed. They were divided into ultrasound combined with endoscopic guidance group and ultrasound-guided group. The demographic and renal stone characteristics, intraoperative and postoperative data were analyzed.Results: A total of 72 patients were included in the study, including 35 patients in the ultrasound combined with endoscopic guidance group and 37 patients in the ultrasound-guided group. There was no difference in demographic and stone characteristics between the two groups.There were no significant differences between the two groups in surgical time, number of tract, hemoglobin decreased, stone free rate, ancillary treatment and postoperative complication rate. The tract establishment time of the ultrasound combined with endoscopic guidance group was significantly less than that of the ultrasound-guided group (P<0.05). There was no tract establishment failure in the ultrasound combined with endoscopic guidance group, while there were 7 cases in the ultrasound-guided group.Conclusions: Ultrasound combined with endoscopic guidance can monitor the establishment of working tract of PCNL in real time. Compared with unitary ultrasonic guidance, the time of tract establishment can be shortened and the failure of tract establishment can be avoided.

Background: Endoscopic combined intrarenal surgery (ECIRS) well established as a minimally invasive procedure for is treatment of multiple urolithiasis. The position is the key to the perfect combination of Percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). Galdakao-modified supine Valdivia (GMSV) and prone split-leg position are widely used. However, both positions have their own advantages and disadvantages. This study aimed at evaluating the effect of ECIRS in the treatment of multiple urolithiasis in the modified prone split-leg position.Patients and methods: Total 96 patients with multiple urolithiasis underwent ECIRS in modified prone split-leg position from September 2017 and January 2021. Relevant demographic and clinical data were analysed retrospectively. Clinical outcomes such as stone free rate, complications and postoperative hospital stay were evaluated. Factors predicting stone free rate were also evaluated. Chi-square test was used to compare categorical variables and Student t test was applied for continuous variables of the treatment groups.Results: The mean renal stones size was 32.5 ± 10.7 mm and renal stone surface area was 712.2 ± 264.8 mm2. The mean ureteral stones size was 24.8 ± 12.3 mm. The mean surgical time was 82.2 ± 38.3 min. The incidence of complications was 16.7%, mainly grade 1 and grade 2. No complications occurred above grade 3. The stone was completely removed in 75 (78.1%) patients in a single operation. The risk factors affecting the stone free rate of ECIRS were analyzed, only the number of involved calyces by stone was found to be significant (p=0.01).Conclusion: ECIRS is safe and effective in the treatment of multiple renal calculi or multiple renal calculi with ipsilateral ureteral calculi in the modified prone split-leg position. The modified of prone split-leg position makes the retrograde operation more convenient, which is conducive to the combination of RIRS and PCNL.