Parenchymal-Sparing Versus Anatomic Liver Resection for Colorectal Liver Metastases: a Systematic Review

Introduction Colorectal liver metastases develop in 50% of patients diagnosed with colorectal cancer. Surgical resection for colorectal liver metastasis typically involves either anatomical resection (AR) or parenchymal-sparing hepatectomy (PSH). The objective of the current study was to analyze data on parenchymal versus non-parenchymal-sparing hepatic resections for CLM. Methods A systematic review of the literature regarding parenchymal-sparing hepatectomy was performed. MEDLINE/PubMed, Cochrane, and EMBASE databases were searched for publications containing the following medical subject headings (MeSH): ''Colorectal Neoplasms,'' ''Neoplasm Metastasis,'' ''Liver Neoplasms'' and ''Hepatectomy''. ''esides, the following keywords were used to complete the literature search: ''Hepatectomy,'' ''liver resection,'' ''hepatic resection,'' ''anatomic/anatomical,'' ''nonanatomic/nonanatomical,'' ''major,'' ''minor,'' ''limited,'' ''wedge,'' ''CRLM/CLM,'' and ''colorectal liver metastasis.'' Data was reviewed, aggregated, and analyzed. Results Two thousand five hundred five patients included in 12 studies who underwent either PSH (n = 1087 patients) or AR (n = 1418 patients) were identified. Most patients had a primary tumor that originated in the colon (PSH 52.2-74.4% vs. AR 53.9-74.3%) (P = 0.289). The majority of studies included a large subset of patients with only a solitary tumor with a reported median tumor number of 1-2 regardless of whether the patient underwent PSH or AR. Median EBL was no different among patients undergoing PSH (100-896 mL) versus AR (200-1489 mL) for CLM (P = 0.248). There was no difference in median length-of-stay following PSH (6-17 days) versus AR (7-15 days) (P = 0.747). While there was considerable inter-study variability regarding margin status, there was no difference in the incidence of R0 resection among patients undergoing PSH (66.7-100%) versus AR (71.6-98.6%) (P = 0.58). When assessing overall survival, there was no difference whether resection of CLM was performed with PSH (5 years OS: mean 44.7%, range 29-62%) or AR (5 years OS: mean 44.6%, range 27-64%) (P = 0.97). Conclusion PSH had a comparable safety and efficacy profile compared with AR and did not compromise oncologic outcomes. PSH should be considered an appropriate surgical approach to treatment for patients with CLM that facilitates preservation of hepatic parenchyma.