Surgery of Colorectal Liver Metastases: Pushing the Limits

The recent advent of more effective chemotherapy and the development of surgical procedures have expanded the pool of resectable patients with colorectal liver metastases (CLM). Two-stage hepatectomy (TSH), associated liver partition and portal vein ligation for staged hepatectomy (ALPPS), and ultrasound-guided enhanced one-stage hepatectomy (e-OSH) are the surgical solutions proposed for these patients, but the range of indications for these procedures vary from institution to institution.

The advantages and disadvantages of each approach are herein discussed. Patients who drop out between the staged operations of TSH limit its success rate, although predictive scores may help with patient selection and thereby optimize the results. Safety and oncological suitability are concerns to be addressed when considering ALPPS. These concerns notwithstanding, ALPPS has introduced an innovative concept in surgery: the monosegmental remnant liver. Studies involving e-OSH have proven the oncological suitability of tumor exposure once the CLM is detached from major intrahepatic vessels. This finding could expand the indications for e-OSH, although the technical challenges that it entails limit its spread among the surgical community. The liver-first approach involves the clearance of tumors from the liver before the colorectal primary is tackled. This approach fully justifies the complexity of e-OSH.

Predictive scores limiting the interstage dropout of TSH, partial and monosegmental ALPPS, and R1 vascular e-OSH justified by solid long-term results represent new insights that could help refne the patient assignment to each of these approaches. Additionally, liver transplantation is an emerging treatment for CLM that should be taken into account.