Principles of the surgical approach in human liver cystic echinococcosis.

Ultrasonography (USG) has recently contributed much to the diagnostic of hepatic cystic echinococcosis (CE). The use of portable ultrasonograph allowed us to perform a community survey among 9482 people living in a high risk area for CE in the Florida Department (Uruguay). Positive USG results were found in 123 asymptomatic patients. 48 out of 51 USG positive cases were surgically confirmed and 3 were found to be false positive. The results of this survey allowed us to propose a new classification of the echographic imaging based on the parasite's various evolutive and involutive stages. The Echinococcus granulosus cyst size was compared with the parasite's evolutive stages. The cyst's segmentary topography and the related risk of CE is evaluated. The importance of cystic-biliary communication is pointed out and its rational surgical treatment described. Finally, an algorithm is presented facilitating the choice of a rational treatment.