Abstract
OBJECTIVE: To study the efficacy of super-mini percutaneous nephrolithotomy (SMP) versus standard PCNL (sPCNL) in the treatment of different sizes of renal stones and the factors influencing the stone clearance rate. The standard PCNL is uniformly abbreviated as sPCNL and super-mini PCNL is uniformly abbreviated as SMP. METHODS: 155 patients with kidney stones who were treated in our hospital during the period of clinical selection March 2023-March 2024 were selected as the research subjects for retrospective study. The patient's data came from the medical record system and they were divided into sPCNL group and SMP group according to different surgical methods to analyze their clinical treatment effects. All patient's stone removal status was categorized into stone-free group and residual stone group. The relevant data were compared between the two groups, conducting covariance analysis for the difference indexes, and incorporating the indexes without covariance problems into the logistic regression model to analyze the relevant factors affecting the presence of residual stones after treatment. The clinical prediction models were constructed and visualized with nomogram, and internal validation was conducted by drawing the receiver operating characteristic curve (ROC curve). RESULTS: When the diameter was > 20 mm, the stone clearance rate of the sPCNL group (89.29%) was higher than that of the SMP group (70.27%), but the difference was not statistically significant (p > 0.05); when the diameter was ≤ 20 mm, the stone clearance rate of the SMP group (94.12%) was higher than that of the sPCNL group (74.36%), and the difference was statistically significant (P < 0.05). Based on the records of the medical record system, 27 patients out of 155 patients, accounting for 17.42%, had residual stones after treatment, which was classified into the stone group, and 128 patients, accounting for 82.58%, had no stones after treatment, which was classified into the stone-free group. The difference between the two groups was statistically significant (x(2)/t/Z = 7.320, 13.869, 9.404, 4.345, 3.840, and 6.209, P < 0.05) when comparing the surgical approach, stone size, number of involved renal calyces, T.O.HO. scores, CT values, and the distance of the stone from the skin (SSD). All the difference variables were analyzed for VIF covariance using the R language (R package: logreg6.2.0) and the VIF of each difference variable was ≤ 10 and the tolerance was ≥ 0.1, so there was no covariance problem, and the above indexes could be included in the logistic regression model, and the results found that all of the above indexes were the risk factors for the stone clearance rate of the patients (P < 0.05). A nomogram prediction model was established, and the AUC value in the ROC curve was 0.966, with a 95% CI of (0.941 ~ 0.992), thus indicating that this clinical prediction model has a good risk prediction degree. CONCLUSION: The treatment effect of SMP is higher in patients with renal stones ≤ 20 mm in diameter, and the treatment effect of sPCNL is higher in patients with renal stones > 20 mm in diameter. Surgical method, stone size, number of involved renal calyces, T.O.HO. score, CT value, and SSD are the independent risk factors influencing the clearance rate of patients' stones. The nomogram based on these six indicators can help preoperatively identify high-risk patients for residual stones, thereby optimizing channel design and follow-up planning.