Parenchymal sparing surgery for colorectal liver metastases: The need for a common definition.

Abstract

e15013 Background: Colorectal cancer metastases (CRLM) are major public health issue. Recently, surgeons have advocated the use of parenchymal sparing surgery (PSS) however, a common definition of the concept is lacking.To clarify and try to validate the concept of PSS to treat CRLM through the available retrospectives studies, including ours. Methods: Retrospective analysis of a cohort of patients treated by combined resections and intra-operative ablation (IOA) based on PSS, prospectively recorded in a database from 2003 to 2015 in a regional referral cancer center. All the patients benefited from the same strategy, constituting a homogenous series.PSS consists of using resection or IOA in order to spare the healthy parenchyma. One-stage is favored over two-stage surgery and use of portal vein embolization was restricted to the minimum.Post-operative complications were the primary endpoint with a special focus on post-operative liver failure. Liver toxicities and overall survival were also scrutinized. Results: Three hundred and eighty-seven patients underwent a PSS out of which 348 patients received a median of 9 pre-operative cycles of oxaliplatin or irinotecan with targeted therapies for half of them. Resection was major in 128 patients, combined with IOA in 137 patients and IOA alone in 50 cases. Thirty-eight patients had a PVO by strict necessity. The 5yr-overall survival was 50.3%. Seventy-eight patients had a complication > grade 3 out of which 10 patients died. Nine patients had a liver failure (LF) grade B and C and four died. There was no difference in post-operative complications comparing minor and major resections, validating our PSS definition. Chemotherapy and liver toxicity were not related to more post-operative complications. Only one patient died from a primitive LF. Conclusions: With PSS, healthy liver is no more a target. Routine use of chemotherapy does not impair the results and severe LFs are rare. PSS is the optimal strategy to treat CRLM. Definition of PSS cannot be based just on the retrived volume but on the ratio Tumor burden/Healthy liver. A major hepatectomy can be a PSS and a minor may not be one. That is why PSS defintion must be clarify especially for further prospective validations.