Surgical approach to achieve R0 resections in primary and metastatic liver tumors: a literature review.

Background and Objective: Primary and metastatic liver tumors are a significant cause of mortality worldwide. Regardless of the etiology of the tumor, macro- and microscopically clear margins (R0) while preserving adequate function of the remaining organ are the main goals after liver resections. However, technically challenging procedures are required to achieve R0 resection. Currently, there is no consensus of which should be the ideal minimal safety margin for liver tumor resections, with contrasting reports in regards of safety, tumor recurrence and overall outcomes following R0. Therefore, we aim to review current worldwide surgical practices to achieve R0 resections for primary and metastatic liver tumors in challenging surgical techniques and their reported outcomes. Methods: PubMed database, Google Scholar, and OVID Medline were searched for peer-reviewed original articles related to surgical techniques performed to achieve R0 resections in the setting of primary and/or metastatic liver tumors. An up-to-date review of English-language articles published between 2015 to July 2022 was performed. Key Content and Findings: Primary and metastatic liver tumors can be effectively treated using hepatic resection. Current literature highlights that tumors involving major vascular structures are not uncommon. Surgical advances have allowed for vascular control techniques, as well as vascular resections to be performed in a feasible and safe manner to achieve R0 resections. Complex resections combining surgical techniques can be performed in certain population after a detailed evaluation. Liver transplantation (LT) have been used with varying degrees of success for treatment of patients with hepatocellular carcinoma, cholangiocarcinoma (CCA), colorectal liver metastases (CRLM), non-resectable CRLM and metastatic neuroendocrine tumors. Conclusions: Safety and feasibility of R0 resections have been reported for multiple techniques. Technical complexity should not be a limitation to achieve or pursue R0 tumor resection. However, there has to be a balance between patient risk/benefit in attempting R0 resections. Adequate training of surgeons on implementation of complex techniques, as well as transplant oncology techniques applied to hepato-pancreato-biliary (HPB) surgery represents as a promising path to improve short and long-term outcomes for liver-related oncology patients.