Surgical Therapy in Patients with Colorectal Liver Metastases

Liver metastases (LM) occur in about 50% of patients with colorectal cancer. Besides the multimodal treatment of the primary tumor, the only way to cure patients with colorectal LM (CRLM) is complete resection. Different surgical procedures for this purpose are available depending on location, size, and number of LM. Additional concepts for patients with primary unresectable LM exist, ranging from Chemotherapy to induction of liver hypertrophy and even liver transplantation. This review intends to provide an overview of the surgical approach.Surgical options in the treatment of CRLM are defined and limited by their intraparenchymal location and their proximity to major vessels and intrahepatic bile ducts. Lesions located in the periphery can be excised in a parenchymal sparing fashion with a small tumor-surrounding resection margin of healthy liver parenchyma. If this is not possible, anatomical resections based on segmental boundaries are performed. In these cases, a sufficient functional volume of liver parenchyma after resection (future liver remnant volume [FLRV]) has to be preserved. This FLRV depends on various factors such as bodyweight and possible preexisting liver damage, such as cirrhosis, fibrosis, or chemotherapy-induced liver impairment. Liver hypertrophy via partial occlusion of the portal venous system is a standard procedure for patients with primary unresectable LM to increase FLRV. Furthermore, discussion of liver transplantation in cases of unresectable LM is gaining importance again. A combination of surgery and adjuvant and/or neoadjuvant chemotherapy may be indicated in individual cases, but general evidence-based recommendations cannot be given without further studies.Surgical removal of all metastases represents the only option of a potentially curative treatment of UICC stage IV colorectal carcinoma with liver involvement. An interdisciplinary approach consisting of chemotherapeutical downsizing and hypertrophy of the FLRV offers potential curative treatment for patients with initially unresectable metastases. For all others, liver transplantation is seeing a revival showing promising results in overall survival compared to chemotherapy alone.