Metal telescopic and Amplatz sheath dilation in nephrolithotomy

Comparison of Amplatz sheath percutaneous nephrolithotomy (Amplatz PCNL) and metal telescopic dilation PCNL (MTD PCNL) with respect to clinical outcomes and complications.

Single-institution retrospective chart review with 73 patients who underwent PCNL divided into two groups: Amplatz PCNL (n = 26) and MTD PCNL (n = 47). Efficacy (stone-free rate, residual stones, and surgical duration) and safety (transfusion rate and hemoglobin decrease) were evaluated. Complications were recorded and classified using the modified Clavien classification system.

The two PCNL groups were similar regarding mean age, stone burden, side, stone location, and stone composition. There were no significant differences in surgery duration (101 ± 28 vs. 98 ± 30 min; P = 0.906), transfusion rate (3.9% vs. 4.3%; P = 0.382), and hemoglobin drop (0.9 ± 0.9 vs. 1 ± 0.7 g/dl; P = 0.424) for Amplatz and MTD PCNL, respectively. Stone-free rate (86% vs. 68%; P = 0.001) was significantly higher while residual fragments rate (37% vs. 60%; P = 0.001) was significantly lower in Amplatz PCNL compared to MTD PCNL. However, tube stay time (4.4 ± 1.8 vs. 5.8 ± 3.6 days; P = 0.005) and hospital time (8.6 ± 2.6 vs. 9.7 ± 5.5 days; P = 0.0001) were significantly longer in Amplatz PCNL compared to MTD PCNL. Clavien grading revealed a significantly higher rate of low-grade complications (I-III) for the MTD PCNL in comparison to Amplatz PCNL (10.6% vs. 3.9%, respectively; P = 0.011). There were no major complications and no tract dilation failure.

The study demonstrates that Amplatz PCNL is a safe and effective procedure to remove large renal stones compared with MTD PCNL.