Irreversible Electroporation for Liver Metastases from Colorectal Cancer: A Systematic Review

Background: Irreversible electroporation (IRE) is a non-thermal form of ablation based on the delivery of pulsed electrical fields. It has been used to treat liver lesions, particularly those in proximity to major hepatic vasculature. The role of this technique in the portfolio of treatments for colorectal hepatic metastases has not been clearly defined. This study undertakes a systematic review of IRE for treatment of colorectal hepatic metastases.Methods: The study protocol was registered with the PROSPERO register of systematic reviews (CRD42022332866) and reports in compliance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA). The Ovid MEDLINE\uae, EMBASE, Web of Science and Cochrane databases were queried in April 2022. The search terms \u27irreversible electroporation\u27, \u27colon cancer\u27, \u27rectum cancer\u27 and \u27liver metastases\u27 were used in combinations. Studies were included if they provided information on the use of IRE for patients with colorectal hepatic metastases and reported procedure and disease-specific outcomes. The searches returned 647 unique articles and the exclusions left a total of eight articles. These were assessed for bias using the methodological index for nonrandomized studies (MINORS criteria) and reported using the synthesis without meta-analysis guideline (SWiM).Results: One hundred eighty patients underwent treatment for liver metastases from colorectal cancer. The median transverse diameter of tumours treated by IRE was <3 cm. Ninety-four (52%) tumours were adjacent to major hepatic inflow/outflow structures or the vena cava. IRE was undertaken under general anaesthesia with cardiac cycle synchronisation and with the use of either CT or ultrasound for lesion localisation. Probe spacing was less than 3.2 cm for all ablations. There were two (1.1%) procedure-related deaths in 180 patients. There was one (0.5%) post-operative haemorrhage requiring laparotomy, one (0.5%) bile leak, five (2.8%) post-procedure biliary strictures and a zero incidence of post-IRE liver failure.Conclusions: This systematic review shows that IRE for colorectal liver metastases can be accomplished with low procedure-related morbidity and mortality. Further prospective study is required to assess the role of IRE in the portfolio of treatments for patients with liver metastases from colorectal cancer

Management of colorectal cancer presenting with synchronous liver metastases

Up to a fifth of patients with colorectal cancer (CRC) present with synchronous hepatic metastases. In patients with CRC who present without intestinal obstruction or perforation and in whom comprehensive whole-body imaging confirms the absence of extrahepatic disease, evidence indicates a state of equipoise between several different management pathways, none of which has demonstrated superiority. Neoadjuvant systemic chemotherapy is advocated by current guidelines, but must be integrated with surgical management in order to remove the primary tumour and liver metastatic burden. Surgery for CRC with synchronous liver metastases can take a number of forms: the 'classic' approach, involving initial colorectal resection, interval chemotherapy and liver resection as the final step; simultaneous removal of the liver and bowel tumours with neoadjuvant or adjuvant chemotherapy; or a 'liver-first' approach (before or after systemic chemotherapy) with removal of the colorectal tumour as the final procedure. In patients with rectal primary tumours, the liver-first approach can potentially avoid rectal surgery in patients with a complete response to chemoradiotherapy. We overview the importance of precise nomenclature, the influence of clinical presentation on treatment options, and the need for accurate, up-to-date surgical terminology, staging tests and contemporary management options in CRC and synchronous hepatic metastatic disease, with an emphasis on multidisciplinary care

The Liver-First Approach to the Management of Colorectal Cancer With Synchronous Hepatic Metastases - A Systematic Review

Importance To our knowledge, this is the first systematic review of the liver-first approach to the management of patients with colorectal cancer with synchronous liver metastases. Objective: To review current evidence for the liver-first approach to the management of patients with colorectal cancer with synchronous liver metastases. Evidence: Review PubMed, EMBASE, the Science Citation Index, the Social Sciences Citation Index, Conference Proceedings Citation Index, and the Derwent Innovations Index were searched for the period from January 2000 to May 2012 using terms describing colorectal cancer, liver metastases, and surgery. A predefined protocol for data extraction was used to retrieve data on the design of each study including demographic profile, distribution of primary and hepatic metastatic disease, management of chemotherapy, surgery, the sequence of intervention, disease progression, the numbers completing treatment algorithm, and outcome and survival. Findings: The literature search identified 417 articles, of which 4 cohort study reports described the liver-first approach and reported survival data. There was good agreement between studies on the sequence of treatment using the liver-first approach. The preferred algorithm was systemic chemotherapy, followed by liver resection, then chemoradiotherapy for those patients with rectal lesions, and colorectal resection as the last operative step. Two protocols provided further adjuvant chemotherapy after colorectal resection. Of 121 patients starting treatment, 90 (74%) completed the specified treatment protocol. Disease progression during the protocol period occurred in 23 patients (19%). There was wide variation in survival despite apparently similar protocols. Conclusions and Relevance: The liver-first approach for patients with colorectal cancer with synchronous liver metastases is possible but is associated with a wide range of survival outcomes, despite protocol similarities between studies. There is a need for a well-designed clinical trial comparing this liver-first approach with the classic (bowel-first) approach