TRANSHEPATIC TOPICAL DISSOLUTION OF GALLBLADDER STONES WITH MTBE AND EDTA - RESULTS, SIDE-EFFECTS, AND CORRELATION WITH CT IMAGING

Forty-two patients with symptomatic gallstones (28 women, 14 men, mean age 49.8 +/- 13.2 years) were recruited for contact dissolution thera py. Pretreatment CT scans of the gallbladder were obtained in every pa tient under standard conditions. For contact dissolution treatment of heterogeneous gallstones or gallstones with attenuation values of more than 50 Hounsfield units, methyl tert-butyl ether and bile acid ethyl ene diaminetetraacetic acid were used in alternating administration at time intervals and durations adapted to the individual tolerance of t he patients. In the case of gallstones with mean attenuation values un der 50 Hounsfield units, the dissolution therapy was performed with me thyl tert-butyl ether alone. In 12 (28.6%) patients a, complete dissol ution of gallbladder stones could be achieved; 11 patients (26.2%) rev ealed gallbladder sludge but no radiologically or sonographically visu alized residual stone debris. The remaining 19 (45.2%) patients had re sidual gallstone debris. Shell fragments in three of five rimmed galls tones, seven of eight laminated gallstones, and all densely calcified stones were refractory to contact dissolution therapy. Dissolution rat es correlated well with mean attenuation values, whereas no significan t correlation was found between stone number and dissolution rates or between stone diameter and dissolution rates respectively. The mean in stillation time required for stones with a mean density of more than 5 0 HU was 17.7 +/- 11.5 hr of bile acid ethylene diaminetetraacetic aci d and 5.8 +/- 3.2 hr of methyl tert-butyl ether. In the case of isoden se stones, the average instillation time of methyl tert-butyl ether wa s 12.3 +/- 4.7 hr. There was a statistically significant difference in methyl tert-butyl ether instillation time between the both groups (P < 0.001), but the total instillation time required for stones with a m ean density of more than 50 HU was significantly longer (P < 0. 0001); consequently, in these patients the incidence of severe complications was higher without reaching statistical significance. Mild complicati ons occurred in 95.2% of patients and severe complications were observ ed in 16.8% of cases. Posttreatment CT examinations after intravenous application of contrast media revealed gallbladder mural hyperemia fol lowed by edematous swelling of the pericystic tissue layer in 96.3% of patients. Eight of eleven patients (72.7%) with gallbladder sludge re vealed gallstone recurrence in the course of a 12-month observation pe riod. In the successfully treated group, only one patient experienced gallstone recurrence (P = 0.0066). In principle, the use of bile acid ethylene diaminetetraacetic acid dissolution medium made the dissoluti on of calcified or pigment stones possible, although the side effects are greater than with cholesterol stones. More effective and safer sol vents for these more difficult to dissolve stones should be sought.