SWL Clears Smaller Stones Better
Researchers at the Ratna Memorial Hospital in Pune, India, studied 910 patients with upper ureteric stones who were treated with SWL as the primary modality with Dornier Compact ‘S' litho-tripter. The patients ranged in age from 9-69 years, and stones ranged in size from 8-20 mm. The duration of symptoms was less than four weeks in 787 patients and more than four weeks in 113.
Stones were smaller than 1 cm in 552 patients and larger than 1 cm in 358. The criteria for stone
clearance were symptomatic relief and confirmation by x-ray and ultrasonography. The overall stone clearance rate was 92% (837 of 910 patients), the investigators reported. The clearance rate was 40.7% for the first treatment, 30% for the second, and 21.2% for the third. The clearance rate was about 95% for stones smaller than 1 cm and 88% for stones larger than 1 cm.
SWL did not clear stones in 73 patients (8%), the researchers noted. Of these, 61 underwent uteroscopy, seven underwent percutaneous nephrolithotomy, and five had an open ureterolithotomy.
Of the 910 patients, 749 presented with colic. The remaining 161 stones were discovered incidentally.