Open drainage versus overlapping method in the treatment of hepatic hydatid cyst cavities.

In order to compare the results of open drainage and overlapping methods, 58 consecutive patients with uncomplicated hepatic hydatid disease were investigated between January 1990 and January 1997. The cavities were obliterated by overlapping method in 26 patients and were left open into the peritoneal cavity following partial pericystectomy in 32 patients. Postoperative complications and follow-up results of ultrasonography (US) and computed tomography (CT) were compared between the two groups. In total, there were 56 cysts in the obliterated group and 83 cysts in the open drainage group. There was no significant difference in age, sex, mean diameter of the cysts, US features of the cysts according to the Gharbi classification, and median follow-up. Mean hospital stay was 10 days in the overlapping group and 7.5 days in the open drainage group (P = 0.033). No postoperative complication was observed in the obliterated group and nearly half of the cyst cavities could not be detected in the early postoperative period by US and CT. Pleural effusion (n = 1) and biliary fistula (n = 1) were detected in the open drainage group which disappeared spontaneously. In the open drainage group, US and CT surveillance revealed that the cyst cavities were reduced in size and the echo pattern was changed in the early postoperative period, whereas the appearance changed into pseudotumor view in the late postoperative period. In conclusion, the cyst cavities disappear perfectly in the overlapping group. Treating the cyst cavity by open drainage is an easy, effective and safe technique. Open drainage can be a 'method of choice' for patients with multiple hydatid cysts and for cysts where management is difficult or unamenable to other methods, but the residual cyst cavities may be misinterpreted as a new cyst by an inexperienced radiologist.