Short and long-term outcomes of laparoscopic compared to open liver resection for colorectal liver metastases

Background: Minimally invasive surgery (MIS) is now established as standard of care for a variety of gastrointestinal procedures for benign and malignant indications. However, due to concerns regarding superiority to open liver resection (OLR), the uptake of laparoscopic liver resection (LLR) has been slow. Data on long-term outcomes of LLR for colorectal liver metastases (CRLM) remain limited. We conducted a systematic review and meta-analysis of short and long-term outcomes of LLR compared to OLR for CRLM. Methods: Five electronic databases were systematically searched for studies comparing LLR and OLR for CRLM and reporting on survival outcomes. Two reviewers independently selected studies and extracted data. Primary outcomes were overall survival (OS) and recurrence free survival (RFS). Secondary outcomes were operative time, estimated blood loss, post-operative major morbidity, mortality, length of stay (LOS), and resection margins. Results: Eight non-randomized studies (NRS) were included (n=2,017 total patients). Six were matched cohort studies. LLR reduced estimated blood loss [mean difference: -108.9; 95% confidence interval (CI), -214.0 to -3.7) and major morbidity [relative risk (RR): 0.68; 95% CI, 0.56-0.83], but not mortality. No difference was observed in operative time, LOS, resection margins, R0 resections, and recurrence. Survival data could not be pooled. No studies reported inferior survival with LLR. OS varied from 36% to 60% for LLR and 37% to 65% for OLR. RFS ranged from 14% to 30% for LLR and 22% to 38% for OLR. According to the grade classification, the strength of evidence was low to very low for all outcomes. The use of parenchymal sparing resections with LLR and OLR could not be assessed. Conclusions: Based on limited retrospective evidence, LLR offers reduced morbidity and blood loss compared to OLR for CRLM. Comparable oncologic outcomes can be achieved. Although LLR cannot be considered as standard of care for CRLM, it is beneficial for well-selected patients and lesions. Therefore, LLR should be part of the liver surgeon's armamentarium.