Analysis of unique liver volume restoration after laparoscopic fenestration of liver cysts

Abstract

Laparoscopic fenestration is a standard procedure for the treatment of non-parasitic liver cysts. After fenestration, the remnant liver often restores its volume. However, no systematic analysis of the phenomenon exists. In the present study, the pattern of liver volume restoration after laparoscopic fenestration of liver cysts was analyzed, and the mechanism for the unique restoration was investigated. Seven patients with giant non-parasitic liver cysts underwent laparoscopic fenestration. Liver volume restoration in each section and changes in the diameter of the portal branch were analyzed after fenestration with CT or MRI. In two patients, regional liver volume restoration was assessed in detail using region-growing software, and change in portal flow distribution was estimated using computational fluid dynamics. Then, the regional liver volume restoration rate was compared with the portal hemodynamic changes. Liver volume restoration after fenestration was dependent on the size and position of the cysts; it not uniform throughout the remnant liver. The liver volume restoration in sections that had been compressed by giant cysts was significantly greater than in other areas after fenestration. This volume restoration was accompanied by an increase in the diameters of the portal branches in these sections. In addition, a strong correlation between the regional liver volume restoration rate and the changes in portal flow distribution existed in the computationally analyzed cases. Liver volume restoration after the fenestration of giant liver cysts non-uniformly occurs in the remnant liver. Improved portal vein circulation in the hepatic area adjacent to the excised giant liver cysts most likely regulates the greater regional volume restoration rate in the area.