Hüseyin Biçer, Abdullah Gölbaşı, Burak Elmaağaç, Ali Yasin Ozercan, Salim Tozan, Mert Ali Karadağ
Purpose: To evaluate whether use of a vacuum-assisted access sheath (VAAS) improves operative efficiency, perioperative safety, early renal function, and stone-free status compared with a conventional access sheath (CAS) during 16F mini-percutaneous nephrolithotomy (mini-PCNL). Patients and Methods: In this prospective comparative study, 80 adults with 2–4 cm renal calculi were assigned to undergo VAAS mini-PCNL ( n = 40) or CAS mini-PCNL ( n = 40). Coprimary endpoints were operative efficiency (operative, lithotripsy, and stone clearance times) and perioperative safety (postoperative fever, infection, hospital stay, Clavien–Dindo complications). Secondary endpoints were early renal function (estimated glomerular filtration rate [eGFR] by Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) and CT-based stone-free status at 1 month. All procedures were performed by a single experienced surgeon using a standardized 16F tract and holmium:yttrium-aluminum-garnet laser lithotripsy. Stone-free status was assessed at 1 month using 1.5-mm thin-slice noncontrast CT and classified as Grade A (no residual fragments), Grade B (A + ≤2 mm fragment), Grade C (A + B + 2.1–4 mm fragment), or nonstone free (>4 mm). Results: VAAS was associated with significantly shorter operative, lithotripsy, and stone clearance times and reduced need for auxiliary instruments (all p s < 0.05). Hospital stay and postoperative pain scores were lower in the VAAS group ( p < 0.001). A significant postoperative eGFR decline was observed in the CAS group but not in the VAAS group, with a significant between-group difference ( p < 0.05). Zero-fragment rates were higher with VAAS (80% vs 67.5%), and clearance ≤4 mm was achieved 90% vs 75%; however, differences were not statistically significant. Stone complexity was significantly associated with zero-fragment outcomes ( p = 0.002). No major (Clavien–Dindo ≥III) complications occurred. Conclusions: VAAS significantly improved operative efficiency and perioperative recovery compared with CAS. Among secondary outcomes, VAAS was associated with better preservation of early renal function, a finding that should be interpreted with caution given its secondary nature. Although stone-free rates were similar, suction-assisted systems may provide functional and procedural advantages in mini-PCNL.