Endoscopy of the gallbladder as control of gallstone therapy with methyl-tert-butyl ether

We report on a 36-yr-old woman with six gallstones measuring 2.1 cm each. Within 21 h of methyl-tert-butyl ether (MTBE) treatment, the stones had dissolved to a small amount of residue. As could be seen from cholesterol concentrations of samples of aspirated gallbladder bile and MTBE fractions, the dissolution process was slow to begin with, and gained momentum during hours 6-11, after which it decelerated. We discontinued treatment after 20 h, since the stone residue showed no change. Cholecystoscopy performed with an Edwards angioscope via a catheter showed that there were no stone remnants, but that there were flat polyps on the gallbladder wall. One hour later, we stopped the therapy. Cholecystoscopy is a useful method of assessing the results of MTBE treatment.