Landmarks and techniques to perform minimally invasive liver surgery: A systematic review with a focus on hepatic outflow.

PURPOSE: In this systematic review, we aimed to clarify the useful anatomic structures and assess available surgical techniques and strategies required to safely perform minimally invasive anatomic liver resection (MIALR), with a particular focus on the hepatic veins (HVs). METHODS: A systematic review was conducted using MEDLINE/PubMed for English articles and Ichushi databases for Japanese articles through September 2020. The quality assessment of the articles was performed in accordance with the Scottish Intercollegiate Guidelines Network (SIGN). RESULTS: A total of 3372 studies were obtained, and 59 were selected and reviewed. Due to the limited number of published comparative studies and case series, the degree of evidence from our review was low. Thirty-two articles examined the anatomic landmarks and crucial structures for approaching HVs. Regarding the direction of HV exposure, 32 articles focused on the techniques and advantages of exposing HVs from either the root or the periphery. Ten articles focused on the techniques to perform a segmentectomy 8 in particularly difficult cases of MIALR. In seven articles, bleeding control from HVs was also discussed. CONCLUSIONS: This review may help experts reach a consensus regarding the best approach to the management of hepatic veins during MIALR.

Defective Mismatch Repair Status was not Associated with DFS and OS in Stage II Colon Cancer Treated with Adjuvant Chemotherapy.

BACKGROUND: Mismatch repair (MMR) status has been proposed, with some controversy, as a prognostic and predictive marker in stage II colon cancer. The aim of this study was to evaluate the association between MMR and survival in stage II colon cancer. METHODS: A total of 860 patients with curatively resected stage II colon cancer were selected for inclusion between January 2003 and December 2008. Tumors lacking expression of MLH1 and/or MSH2, as determined by immunohistochemistry, were classified as having deficient MMR (dMMR), whereas other tumors were classified as having proficient MMR (pMMR). Clinical risk (CR) factors were used to divide patients into high or standard CR groups. RESULTS: Of 860 patients, 14.7 % were dMMR, 42.4 % had ≥1 CR factors, and 85.8 % patients received adjuvant chemotherapy. MMR status did not affect disease-free survival (DFS; hazard ratio [HR] 1.191, p = 0.415) or overall survival (OS; HR 1.300, p = 0.344). Among CR factors, only pathologic T4 disease tended to associate with poor OS (HR 1.979, p = 0.071). Adjuvant chemotherapy was associated with better DFS (HR 0.393, p < 0.0001) in patients with pMMR tumors. However, in patients with dMMR tumors, adjuvant chemotherapy was not associated with DFS. CONCLUSIONS: MMR status did not affect DFS or OS in patients with stage II colon cancer. In patients treated with adjuvant chemotherapy, dMMR was not associated with DFS and OS. However, adjuvant chemotherapy was associated with improved DFS in pMMR patients.