Formation of venous collaterals and regeneration in the donor remnant liver: volumetric analysis and three-dimensional visualization.

PURPOSE: We sought was to quantify and visualize the regeneration of the remnant liver after living donor liver transplantation using computed tomographic (CT) data. METHODS: For the evaluation of preoperative and follow-up data, we developed a software assistant that was able to compute the volume growth of the remnant liver and liver territories as well as visualize the individual growth of hepatic vessels over time. The software was applied to CT data of 20 donors who underwent right hepatectomy including the middle hepatic vein with at least 3 follow-up examinations in the first year after transplantation. RESULTS: After donation of a right lobe graft, the remnant liver regenerated by an average 77% of the original volume within the first 3 postoperative months and to 86% within the first year. The growth of the left lateral segments was increased compared with that of segment IV in all cases. The visualization showed the growth of the portal vein and the hepatic veins. With the simultaneous display of pre- and postoperative results, it was possible to detect the formation of collaterals between truncated segment IVb veins and the veins of segment IVa or of the left lateral lobe. CONCLUSION: The software-assisted analysis of follow-up data yielded additional insight into territorial liver regeneration after living donor liver transplantation and allowed for reliable detection of relevant hepatic vein collaterals using CT data.

[Virtual hepatic surgery - computer-assisted operation planning on the 3-dimensional reconstructed liver]. / Virtuelle hepatobiliäre Chirurgie - computerunterstützte Resektionsplanung an der dreidimensional rekonstruierten Leber.

Recent developments in image-based computer assistance provide an improved visualisation of the intrahepatic vascular branching system in a virtual three-dimensional model of the liver, allowing a quantitative assessment of any vascular territory. The advantages of computer-assisted resection planning refer to a better preoperative assessment of functional resectability in areas at risk for either devascularisation or impaired drainage. In selected cases, this information may have a considerable influence on operative planning, especially with regard to the extent of resection or the need for vascular reconstruction. Due to the great anatomical variability of the intrahepatic branching patterns of the right liver lobe, this seems to be particularly important in extended left hepatectomies or in repeat hepatectomy when intrahepatic vascular anatomy may be altered. The development of navigation techniques to ensure the accurate application of the preoperative planned resection line is under investigation but not available yet.