Expanding indications for laparoscopic parenchyma-sparing resection of posterosuperior liver segments in patients with colorectal metastases: comparison with open hepatectomy for immediate and long-term outcomes

Background Laparoscopic liver resection (LLR) of posterosuperior segments (PSS) is still technically demanding procedure for highly selective patients. There is no long-term survival comparative estimation after LLR and open liver resection (OLR) for colorectal liver metastases (CRLM) located in PSS. We aimed to compare long-term overall (OS) and disease-free survival (DFS) after parenchyma-sparing LLR with expanding indications and open liver resection (OLR) of liver PSS in patients with CRLM. Methods Two Russian centers took part in the study. Patients with missing data, hemihepatectomy and extrahepatic tumors were excluded. One of contraindications for LLR was suspicion for tumor invasion in large hepatic vessels. Logistic regression was used for 1:1 propensity score matching (PSM). Results PSS were resected in 77 patients, which accounted for 42% of the total number of liver resections for CRLM. LLR were performed in 51 (66%) patients. Before and after matching, no differences were found between groups in the following factors: median size of the largest metastatic tumor; proximity to the large liver vessels; the rate of anatomical parenchyma sparing resection of PSS; a positive response to chemotherapy before and after surgery. Regardless of matching, the size of the largest metastases was above 50 mm in more than one-third of patients who received LLR. Before matching, intraoperative blood loss, ICU stay and hospital stay were significantly greater in the group of OLR. No 90-day mortality was observed within both groups. There were no differences in long-term oncological outcomes: 5-year OS after PSM was 78% and 63% after LLR and OLR, respectively; 4-year DFS after PSM was 27% in both groups. Conclusion Laparoscopic parenchyma-sparing resection of PSS for CRLM are justified in majority of patients who have an indication for OLR if performed in high volume specialized centers expertized in laparoscopic liver surgery.