A study on the passage of the upper urinary tract stones after in situ ESWL

Abstract

Two hundred patients with upper urinary tract stones underwent in situ ESWL with Lithostar during the recent 20 months at Kanagawa Prefectural Atsugi Hospital. Actual residual stone rates were calculated based on the period from the initiation of the treatment to the stone free status, and discussed according to the location and size of the stone treated. Total 200 patients were submitted to 1.67 +/- 0.97 treatment sessions with 6742 +/- 5545 shock waves. After 3 months, 148 patients (78%) showed stone free status, and 32 patients (16%) had residual stones less than 4 mm. The actual residual stone rates were 90.5%, 66.5%, 39.1%, 26.9% and 17.9% after 1, 3, 6, 12 and 20 weeks, respectively. The residual stone rate were lower in the lower ureter, uretero-pelvic junction, upper ureter, renal parenchyma or diverticulum and renal pelvis or calyx in order. As for the size, the larger the stones the higher the residual stone rates; the therapeutic results were significantly worse in patient group of stones larger than 21 mm compared to the patient group of smaller stones (p less than 1%). The destructed stones were passed gradually up to 6th week after in situ ESWL, however, after that fragments seldom passed out. Therefore, it was concluded that decision on the additional or combination therapeutic intervention, if necessary, should be made after 6 weeks. Combination therapy with endoscopic surgery and/or others was seemingly needed for the patients with stones of more than 21 mm in size and of renal pelvis and renal calyx to improve the rates of stone free.