Vacuum-Assisted Access Sheath Improves Operative Efficiency and Preserves Early Renal Function in Mini-Percutaneous Nephrolithotomy: A Prospective Comparative Study.

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 ps < 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.