The effects of hydronephrosis and stone burden on success rates of shockwave lithotripsy in pediatric population.

Objectives: To evaluate the efficacy of shockwave lithotripsy (SWL) with a third-generation SWL machine in the pediatric age group and to determine the effects of stone burden and the degree of hydronephrosis on the results.

Methods: Two hundred and sixty children with urinary system stones were treated with Siemens Lithostar Modularis Uro-Plus. The patients were divided into three groups according to stone burden (group 1: <100 mm(2); group 2: 101-200 mm(2); group 3: >200 mm(2)) and into four groups according to the degree of hydronephrosis (group 0: absent; group 1: mild; group 2: moderate; group 3: severe). These groups were compared in terms of the success rate of SWL.

Results: Two hundred and seventy-nine renoureteral units of 260 patients were treated with 402 SWL sessions. The average stone burden was 98.2 mm(2) (range: 11-525). The overall success rate was 87.5%. According to stone burden, the success rate was 93.1% in group 1, 85.5% in group 2, and 60% in group 3 (p < 0.001). According to the degree of hydronephrosis, the success rate was 93.8% in group 0, 89.6% in group 1, 73.3% in group 2, and 64.3% in group 3 (p < 0.001). The average energy, number of shockwaves, number of sessions, retreatment rate, auxiliary procedure rate, and overall efficacy quotient were 1.76 units, 2260, 1.4, 33%, 8.2%, and 0.62, respectively.

Conclusion: SWL is an effective treatment method in selected patients in pediatric age group. However, percutaneous nephrolithotomy can be the first alternative for stones larger than 200 mm(2). It should also be kept in mind that the success rate of SWL decreases when the degree of hydronephrosis increases.