Application of tubeless mini-percutaneous nephrolithotomy under local anesthesia and lateral position in ambulatory...

We conducted a retrospective pilot feasibility study to evaluate whether tubeless mini-percutaneous nephrolithotomy (Mini-PCNL) performed under local anesthesia in the lateral position could be safely implemented in an ambulatory surgery setting for selected upper urinary tract calculi patients. Sixty patients who underwent Mini-PCNL at Lishui People's Hospital between 2021 and 2024 were divided into two groups based on treatment setting: 30 patients received local anesthesia in ambulatory surgery, while 30 received general anesthesia as inpatients. Groups were formed by patient and physician preference rather than randomization, introducing substantial selection bias. All procedures were completed successfully. The ambulatory group demonstrated shorter median operation time (57.9 versus 73.9 min, P < 0.001), shorter hospitalization (1.0 versus 7.4 days, P < 0.001), and lower costs (9041 versus 15186 yuan, P < 0.001) after Bonferroni correction for multiple comparisons. Stone clearance rates were similar between groups (93.3% versus 90.0%, P = 0.641). Secondary outcomes, which were exploratory and uncorrected, showed smaller increases in serum creatinine and urea nitrogen in the ambulatory group (P = 0.014 and P = 0.026), though these may represent Type I error. Anesthesia complications were less frequent (3.3% versus 20.0%, P = 0.017), but this comparison is clinically inappropriate as it includes complications specific to general anesthesia. Important limitations included the retrospective design, lack of randomization, exclusion of patients with hypertension or diabetes, single-center implementation, and potential for unmeasured confounding. While this integrated protocol appears feasible for highly selected patients, the profound selection bias precludes any conclusions about comparative effectiveness or safety. These preliminary findings require validation through prospective randomized controlled trials before clinical implementation can be recommended.