Impact of Stone Size, Location, Composition, Impaction, and Hydronephrosis on the Efficacy of Holmium:YAG-Laser Ureterolithotripsy

Abstract

ObjectivesThe impact and outcome of holmium:YAG-laser (Ho:YAG) ureterolithotripsy in treating proximal and distal ureteral stones was investigated. MethodsA total of 543 patients harbouring proximal (n=194) or distal (n=349) ureteral stones underwent semirigid Ho:YAG ureterolithotripsy. The degree of hydronephrosis; stone size, location, impaction, and composition; and complication and stone-free rates were recorded. ResultsMean stone size for proximal and distal stones was 7.1±3.6mm and 6.2±2.5mm, respectively. The stone-free rate on the first postoperative day was 79.4% for proximal and 96.8% for distal stones (p<0.0001). For proximal stones <10mm and ≥10mm, respectively, the stone-free rate was 80.5% and 74.3% (p=0.4) and for distal stones 97.3% and 94.3% (p=0.2). Stone-free rates for radio-opaque versus radiolucent stones in proximal stones were 79.6% versus 77.9% (p=0.8) and 97.6% versus 96.2% in distal stones (p=0.5). Impaction correlated significantly with stone-free rates (p<0.0001). Stone-free rates for nonimpacted versus impacted proximal stones were 85.8% versus 67.2% (p=0.003) and for distal stones 99.2% versus 91.4% (p<0.003), respectively. The presence or degree of hydronephrosis did not correlate with treatment success (p=0.4, p=0.8). The presence of intraoperative complications correlated significantly with proximal compared to distal ureteral stone location (p=0.004). Auxiliary measures in proximal versus distal stones were performed in 20.6% versus 2.9% (p<0.0001). ConclusionsIn this series, stone-free rates in Ho:YAG ureterolithotripsy were significantly higher in distal and nonimpacted stones but were independent of stone size and composition and the degree of hydronephrosis. Ureterolithotripsy in proximal stones was associated with higher intraoperative complication and retreatment rates compared to distal stones.