Vacuum-assisted mini-percutaneous nephrolithotomy is associated with lower rates of infectious complications compared to standard procedures in low-risk patients: a single-center experience.

Abstract

Purpose: To evaluate the impact of vacuum-assisted mini-percutaneous nephrolithotomy (vamPCNL) vs. vacuum-cleaner mPCNL (vcmPCNL) on the rate of postoperative infectious complications in a cohort of patients with low risk factors for infections.

Methods: We retrospectively analysed data from 229 patients who underwent mPCNL between 01/2016 and 09/2024. Patient's demographics, stones characteristics and operative data were collected. vamPCNL and vcmPCNL were performed based on the surgeon's preference. Low-risk patients were defied as: preoperative negative urine culture, no history of previous UTIs and immune system disease, no preoperative indwelling stent or catheter, single-stage procedure. Complications were graded according to modified Clavien classification. Descriptive statistics and logistic regression models were used to identify factors associated with postoperative infectious complications.

Results: Median (IQR) age and stone volume were 56 (47-66) years and 1.7 (0.8-3.6) cm³, respectively. vamPCNL and vcmPCNL were performed in 177 (77.2%) and 52 (22.8%) cases, respectively. Infectious complications occurred in 23 (10.0%) cases after surgery. Patients who developed infectious complications were more frequently female (59% vs. 32.3%, p = 0.02), had larger stone volume (p = 0.02) and higher rate of multiple stones (p = 0.02) than those who did not. Infectious complications occurred more frequently after vcmPCNL than vamPCNL (19.6% vs. 6.8%, p = 0.01) in this cohort of low-risk patients. Longer operative time (p < 0.01) and length of stay (p < 0.01) were observed in cases with infectious complications. At multivariable logistic regression analysis, vcmPCNL procedures (OR 4.1, p = 0.01) were independently associated with the risk of infectious complications post mPCNL, after accounting for stone volume. Similarly, female gender (OR 2.6, p = 0.03) emerged as a predictor for infectious complications in low-risk patients even after accounting for vcmPCNL procedures.

Conclusion: In a cohort of patients with kidney stones and low-risk factors for infections, approximately 10% of participants developed infectious complications after mPCNL. Patients with infectious complications had higher stone burden and longer procedural time than those who did not, as expected. vamPCNL confirmed to be associates with lower risk of infections, compared to vcmPCNL, even in patients with low risk factors.