Resection proposals for oncologic liver surgery based on vascular territories

摘要

We describe the generation and visualization of resection proposals for oncologic liver surgery which are based on vascular territories of the portal and hepatic vein. Resection proposals are interactively controlled by one parameter: the desired security margin around a tumor. Resection proposals consider vascular structures inside this margin, dependent vascular structures in the periphery as well as the territories supplied by them. The methods have been applied to artificial data from corrosion casts as well as to 5 datasets obtained in the clinical routine from 3 hospitals. In preoperative planning of liver surgery two major questions have to be answered. Most important is, whether the patient and the liver lesions are suitable for surgery. If this question could be affirmed, the extent of the resection must be determined precisely. If a resection with a sufficient security margin can be performed the probability that all tumor cells were removed increases, leading to a better long-term outcome. On the other hand, for sufficient function of the remnant liver as little as possible liver parenchyma should be resected. Calculation of resection proposals must take both of these contrary objectives into account. The basic idea of generating resection proposals is to consider the patient individual vascular branches in the security margin around a tumor, the dependend branches in the periphery, and the territories supplied by them. Surgery planning is particularly difficult if several liver metastases are present or if a metastasis is located centrally, i.e. near one of the major vessels of the liver. Important factors for the assessment of the resectability are the blood supply of the surrounding tissue and the localization of large intra-hepatic vessels. The term "anatomical resection" comprises all resections that represent vascular territories. These are, for example, segment resections or sector resections, the latter affecting only the vascular territories of smaller branches [1]. hi contrast to this, resections that are only based on the extent of the tumor are called "atypical resections". The outcome of these atypical resections seems to be inferior to that of anatomical resections.