Objective:To compare the efficacy and safety of percutaneous nephrolithotomy (PCNL) with negative pressure suction sheath and PCNL with traditional expanded sheath in the treatment of infectious renal calculus.Methods:From May 2019 to June 2022 in our department, 35 patients with infectious renal calculus who received PCNL with negative pressure suction sheath (negative pressure sheath group, NPS group) and another 35 patients with infectious renal calculus who received PCNL with traditional expanded sheath (control group) were determined in our research. Propensity score matching (PSM) was conducted. Preoperative clinical data of the 2 groups was similar and there were no statistical differences between the 2 groups in the age [(45.5±6.8)vs. (44.9±7.3) years old, P=0.723], gender (man/woman 19/16 cases vs. 21/14 cases, P=0.629), body mass index(BMI) [(24.2±4.2)kg/m 2vs. (24.5±3.9)kg/m 2, P=0.758], American Society of Anesthesiologists risk score(ASA) (grade 1/grade 2: 30/5 cases vs. 29/6 cases, P=0.743), sides of calculus (left/right: 18/17 cases vs. left 17/18 cases, P=0.811), Guy’s stone score (grade Ⅰ/Ⅱ/Ⅲ: 3/25/7 cases vs. 1/29/5 cases, P=0.443), CT value of calculus [(629.2±98.8)HU vs. (608.5±105.1)HU, P=0.399], urinary leucocyte (-/+ /+ + : 29/5/1 cases vs. 28/5/2 cases, P=0.839), hypertension(3 cases vs. 5 cases, P=0.707), diabetes(2 cases vs. 2 cases, P=1.000). The ureteral catheter on the affected side was indwelled in the lithotomy position, and ultrasound guided positioning puncture was performed on the affected renal side of the posterior axillary line in the prone position. The puncture channel was established and then expanded to F20 successively, and the lithotriptic sheath was placed to establish the lithotriptic channel. Compared with the traditional expanded sheath, the negative pressure suction sheath was different in that the collateral suction channel was added on the main gravel channel and connected with continuous negative pressure suction. The negative pressure was 40 kPa. All patients were treated with pneumatic ballistic lithotripsy combined with holmium laser. KUB was performed within 1 week after surgery. We defined stone removal as either no residual stones or clinically insignificant residual stones (≤4 mm) which did not cause urinary obstruction. The intraoperative duration of operation and postoperative clinical parameters [white blood cell(WBC), procalcitonin(PCT), C-reactive protein(CRP), hemoglobin(Hb), stone clearance rate] and incidence of perioperative complications were compared between the 2 groups. Results:The operation time of NPS group was lower than that in control group [(35.6±19.5)min vs. (45.4±20.2)min, P<0.05]. The proportion of patients with increased WBC, PCT and CRP in blood after operation in NPS group was lower than that in control group, and there were (WBC: 25.7% vs. 54.3%, P<0.05), (PCT: 42.9% vs.68.6%, P<0.05) and (CRP: 62.9% vs.85.7%, P<0.05) respectively. There was no significant difference in the proportion of patients with decreased Hb postoperatively between the 2 groups (2.9% vs. 8.6%, P=0.607). There was no significant difference in calculus clearance rate postoperatively between the 2 groups (97.1% vs. 94.3%, P=1.000). Postoperative calculus component analysis of the 2 groups suggested that all patients had infected calculus dominated by ammonium magnesium phosphate and phosphate apatite. The incidence of perioperative complications in NPS group was lower than that in control group (22.9% vs. 51.4%, P<0.05). The proportion of patients with fever (body temperature>37.5℃) postoperatively in NPS group was lower than that in control group (14.3% vs. 37.1%, P<0.05). There were 2 and 3 patients respectively required upgraded antibiotic therapy after operation in the 2 groups ( P=1.000). There was one patient respectively with urinary tract obstruction and renal colic due to blood clots postoperatively in each group ( P=1.000). There was one patient with urinary sepsis in control group after operation ( P=0.476). Conclusions:Compared with PCNL with traditional expanded sheath, PCNL with negative pressure suction sheath can save operation time for infectious renal calculus, and reduce the incidence of postoperative infection and perioperative complications. Therefore, the safety of negative pressure suction sheath is higher. However, there is no difference in stone clearance rate between them.