Laparoscopic approach to hydatid liver cysts. Is it logical? Physical, experimental, and practical aspects.

Background: In recent years attempts have been made to treat hydatid liver cysts laparoscopically. The purpose of this study was to evaluate different aspects of this approach and to examine whether a reasonable model could be developed.

Methods: Three different subjects were analyzed. In the first, physical aspects related to transmembrane pressures were analyzed to demonstrate that evacuation of the cyst under pneumoperitoneum does not carry increased risk of spillage, and may even offer an advantage when the proper technique is used. In the second subject, an isolated liver model of a goat was used to study several techniques for evacuating hydatid cysts without spillage. This was tested qualitatively by demonstrating scolices in the fluid medium around the isolated liver after surgical manipulations. In the third subject, the implication of the technique was evaluated in human patients.

Results: According to basic physical assumptions, the following conclusions were reached: (1) The increase in intracystic pressure is equal to or less than the increase in intraperitoneal pressure after pneumoperitoneum. (2) Aspiration of parasitic cysts by laparoscopic needle through a large cannula under "vacuum" or by sealing the cannula and adhering it to the liver by cyanoacrylate or fibrin glue was found to be very safe. Simple needle aspiration failed to prevent spillage. (3) A new transparent cannula 18 mm in diameter with a beveled tip was designed that enables good accessibility to liver cysts and safe evacuation even of huge and complex cysts.

Conclusions: The novel technique to manage hydatid liver cysts, described in the study, is feasible, sensible, and safe. The isolated goat liver containing hydatid cysts can be used as a reliable animal model to test new techniques in the future.