Extracorporeal shock wave lithotripsy: elimination of densely calcified gallstones and gallstones with calcified rims

Objective Until now, radiopaque gallstones have been excluded from extracor poreal shock wave lithotripsy (ESWL), because these stones in vivo are less sensitive to the forces that cause disintegration. In Japan there is a hig her percentage of patients with radiopaque gallstones than in Western count ries. Our purpose in working with patients in Japan was to warrant extensiv e indication of ESWL to radiopaque gallstones, especially densely calcified stones, Design/Methods Retrospective analysis of clinical data. Patients were class ified by computed tomography (CT) of stones, Group A consisted of 78 patien ts whose gallstones were densely calcified (CT attenuation values in Hounsf ield units (HU), 473 +/- 323). Group B consisted of 22 patients whose stone s had a calcified rim (CT attenuation values, 357 +/- 244). Ninety-eight pa tients received adjuvant dissolution therapy with ursodeoxycholic acid. Oth er recommendations, such as a glass of milk at night, were not given to the patients. Setting One university hospital and one general hospital. Patients One hundred consecutive Japanese patients with radiopaque stones i n contractile gallbladder (CT attenuation values, >150 HU, 447 +/- 310, mea n SD) were the subjects. With respect to the efficacy of ESWL, a degree of calcification for stones and its relationship with the rates of stone fragm entation and disappearance were assessed. Fragmentation to less than 3 mm i n stone diameter was the aim, without limit of shock wave discharges and se ssions. Results After ESWL sessions stones were fragmented successfully in 74 of th e 100 patients (57 of the 78 patients in Group A, and 17 of the 22 patients in Group B). The mean number of discharges per patient was 10 435 +/- 8726 , The mean number of discharges for successful stone fragmentation of Group A (9839 +/- 8187) was not significantly different from that of Group B (11 376 +/- 6344). One year after lithotripsy, 60 of the 100 patients were fre e of stones (45 in Group A, and 15 in Group B). Conclusion It appears that patients with either densely calcified gallstone s, or those in whom the stones have a calcified rim, are both suitable cand idates for lithotripsy. Eur J Gastroenterol Hepatol 12:305-312 (C) 2000 Lip pincott Williams & Wilkins.