Mini percutaneous nephrolithotomy (mPCNL) has equivalent stone free rates (SFR) compared with standard PCNL. The latest EAU guidelines suggest that there is evidence for using suction as a complementary tool during mPCNL. We report 30 day perioperative outcomes between suction (smPCNL) and non-suction mPCNL.

This was a prospective, multicentre, investigator-initiated study by 20 surgeons from 14 countries who performed both smPCNL and non-suction mPCNL from January to December 2024. The primary outcome was to assess complete stone free status (Grade A) on a 30-day CT scan. Optimal propensity score matching (PSM) covariate was achieved with absolute standardized mean difference (ASMD) < 0.1 at a caliper width of 0.004. Outcomes were analyzed using either T-test or Mann-Whitney U test. Categorical data between groups were analyzed using Chi-squared test.

Of 1915 patients (1534 smPCNL, 381 non-suction), PSM yielded 664 smPCNL and 309 non-suction patients. Baseline characteristics and stone characteristics including Guy's stone score, Hounsfield units, largest stone diameter and stone location were well matched. Both groups showed high 30-day 100% SFR (i.e Grade A) (85% vs 87%, OR 0.9 [CI 0.59-1.37], p=0.637). SmPCNL group had shorter operative time (42 vs 57mins, p<0.001), high intraoperative SFR determined by visual inspection or fluoroscopy (82.6% vs 69.6%, p<0.001) and lower blood transfusion rates (1.4 vs 3.6%, p=0.044). Infectious complications did not differ. On multivariate analysis, stone volume (OR 0.93, 95% CI [0.89; 0.97], p=0.002), fluoroscopy associated with ultrasound guided access (OR=0.44, 95%CI [0.26; 0.73], p=0.002) and sheath size <20 Fr (OR=0.4, 95% CI [0.21; 0.74], p=0.004) were factors significantly associated with lower odds of Grade A SFR.

Suction in mPCNL improves intraoperative stone clearance rates and reduces operative time but does not impact 30-day SFR or infectious complications. Mini-PCNL can safely achieve zero residual fragments with and without the use of suction sheath in high percentage of cases. This information allows surgeons to adopt and tailor the surgery based on the availability of armamentarium.