Should the presence of other diseases exclude subjects as controls in studies of gallbladder response to cholecystokinin octapeptide (sincalide)? scintigraphic results in patients with malignancies butno known gallbladder disease

Findings on hepatobiliary scintigraphy with intravenous cholecystokinin octapeptide (sincalide) were examined in 26 asymptomatic patients with various malignancies but no known pre-existing gallbladder disease, and normal hepatobiliary and gallbladder morphology on sonography. The maximum gallbladder ejection fraction (GBEF) following a 30 min infusion of 0.04 μg kg ^-1 sincalide ranged from 2 to 100%, with a mean of 68%, a median of 78% and GBEF < 35% in five patients (19%), findings similar to those reported in ’normal’ subjects. There was no correlation between decreased GBEF and the previous chemotherapy agents received, as well as with gallbladder wall thickness, volume, and whether the gallbladder or small bowel was seen first on scintigraphy. These results suggest that despite the presence of other diseases and histories which include extensive chemotherapy, asymptomatic patients with normal hepatobiliary sonography can serve as controls in studies of gallbladder contractility using sincalide.