Abstract:

Objective: To investigate the efficacy and safety of mini-track, mini-nephroscopy and mini-ultrasonic probe percutaneous nephrolithotomy (3mPCNL) for the treatment of 1.5-2.5 cm kidney stones. Methods: The perioperative data and postoperative follow-up data of a total of 25 patients with about 1.5-2.5 cm kidney stones who underwent 3mPCNL under ultrasound guidance in Peking University People's Hospital from November 2023 to January 2024 were retrospectively analyzed. During the matching period, the 25 patients with 1.5-2.5 cm kidney stones receiving standard percutaneous nephrolithotomy (sPCNL) were matched one-to-one according to the criterion that the absolute difference of the maximum diameter of stones between the two groups was less than 1 mm. The operative time, renal function changes, postoperative stone-free rate, hemoglobin changes, and complication rate of the two treatments were compared, and then the effectiveness and safety of 3mPCNL were preliminarily analyzed. Results: There were no significant differences in mean age, preoperative median creatinine, preoperative mean hemoglobin, preoperative mean hematocrit, median stone maximum diameter, and median stone CT density between the 3mPCNL group and the sPCNL group. The median operation time in the 3mPCNL group was 60.0 (45.0-110.0) min, with no statistical significance compared with the sPCNL group, and all the patients underwent single-channel operations. The mean hemoglobin after operation in the 3mPCNL group was (115.3±15.5) mmol/L, and there was no significant difference between the preoperative group and the sPCNL group, and the mean hemoglobin decreased significantly between the sPCNL group and the sPCNL group [(9.5±2.2) mmol/L vs. (10.1±1.9) mmol/L]. The mean hematocrit after operation was (28.0±5.2)%, and the difference was statistically significant compared with that before operation (t=2.414, P=0.020). The mean hematocrit drop was not statistically signi-ficant compared with the sPCNL group (2.3% vs. 2.7%). The median serum creatinine in the 3mPCNL group was 74.0 (51.0-118.0) μmol/L after operation, and the difference was statistically significant compared with that before operation (Z=-2.980, P=0.005). The stone-free rate in the 3mPCNL group and the sPCNL group was 96.0% and 97.3%, respectively, and the mean hospital stay was (4.3± 1.4) d and (5.5±2.0) d, respectively, with the statistical significance (t=0.192, P=0.025). After the operation, one patient in sPCNL group had massive hemorrhage after the nephrostomy tube was removed, which was improved after selective renal artery embolization. One patient in the 3mPCNL group developed mild perirenal hematoma, which was improved after conservative treatment, and no complications were observed in the other patients. Conclusion: 3mPCNL in the treatment of 1.5-2.5 cm kidney stones can achieve an effective rate comparable to sPCNL, and can achieve the ideal stone-free rate in a shorter operative time with a lower rate of surgery-related complications.

Key words: Kidney calculi, Mini-nephroscopy, Mini-ultrasonic probe, Urologic surgical procedures