Parenchyma transection in adult live donor liver transplantation: The virtual dilemma of "where to cut"

BACKGROUND/AIMS: Adequate venous drainage is essential to prevent parenchyma congestion in graft and remnant livers after adult live donor liver transplantation (ALDLT). The areas particularly prone to congestion are the right and left medial sectors. The purpose of our study was to evaluate two types of liver transection techniques (Cantlie, Malagó) frequently encountered in ALDLT and to determine their resulting anatomical and functional liver graft volumes. METHODOLOGY: Livers from 58 potential live liver donors were subject to a virtual 3-dimensional liver partition for right graft hepatectomy. Anatomical (post-transectional) volumes of both right graft and left remnant livers in either liver partition group were initially estimated and corresponding anatomic-GVBWR for the graft hemiliver was calculated. Additionally the potential venous drainage impairment in the medial area of the graft, which was influenced by the two different transection planes, was estimated giving the baseline for the calculation of the functional-GVBWR of the graft. RESULTS: Computer analysis showed no statistically significant differences in the anatomical volumetric parameters between the two potential types of liver partition. However, virtual liver partition following the Cantlie line showed significant decrease of functional volumetric parameters for right liver graft, due to incidental detachment of the right-sided tributaries of middle hepatic vein. CONCLUSIONS: Image-based computer assistance allows for areas at risk for devascularization or venous congestion to be identified and calculated before parenchyma transection in ALDLT. According to the results of this study, minimal modifications of the transection line can provide significant increases in functional volumetric parameters by avoiding venous congestion in the marginal zone of the graft, drained by the middle hepatic vein.