Extracorporeal shockwave lithotripsy of gallbladder stones: correlation of sonographic type and clearance rateof stone

Journal of Korean Society of Medical Ultrasound 1994;13(1): 13-18.

ABSTRACT

The prognosis of the patients with gallstones after extracorporeal shockwave lithotripsy(ESWL) is greatlyinfluenced by the clearance rate of stone fragments. To evaluate the factors affecting the clearance rate of stonefragments after ESWL of gallstones, we compared the sonographic characteristics of gallstones and fragments withthe clearance rate in 161 patients. The stone fragments seen on follow-up sonography were classified into thescattering, layering, and clumping types. Scattering type was seen in 43 cases, layering type in 89, and clumpingtype in 29. There was no significant correlation between the sonographic characteristics of gallstones (shc as thesize of gallstone and the presence of calcification) and the sonographic type of stone fragments. The clearancerates of stone fragments for the scattering, layering, and clumping types were 73.3%, 42.5%, and 23.0%repectively. Non-calcified stones showed higher clearance rate(53.2%) as compared with calcified stones(48.6%).Sonographic type I stones showed higher rate(62.0%) of clearance as compared with type II stones(21.4%). Thestones smaller than 20mm showed higher rate (51.0-53.0%) of clearance as compared with those larger than20mm(40.9%) In summary, the clearance rate of stone fragments in patients with gallstones after ESWL was betterwhen the gallstones were not calcified and small, and when the fragments were scattering type on follow-upsonography

Keywords: Gallbladder,calculi