Timing of resection of synchronous colorectal liver metastasis: A systematic review and meta-analysis.

Abstract

The resection of the primary colorectal tumor and liver metastases is the only potentially curative strategy. In such cases, there is no consensus on whether the resection of the primary tumor and metastases should be performed simultaneously or whether a staged approach should be performed (resection of the primary tumor and after, hepatectomy, or the "liver first" approach). The aim of this study is to evaluate the results of hepatectomy associated with colectomy in colorectal neoplasms, comparing simultaneous and staged resection. A systematic literature review was performed in PubMed, Embase, Cochrane, Lilacs, and manual reference search. The last search was in July/2021. Inclusion criteria were: studies that compared simultaneous and staged hepatectomy for colorectal liver metastasis; studies that analyze short and/or long-term outcomes. Exclusion criteria were reviews, letters, editorials, congress abstract, and full-text unavailability. Perioperative outcomes and overall survival were evaluated and, for staged resections, the outcomes associated with each procedure were added. The ROBINS-I and GRADE tools were used to assess the risk of bias and quality of evidence. Synthesis was performed using Forest plots. The PRISMA criteria (PROSPERO: CRD42021243762) were followed. The initial search collected 5655 articles and, after selection, 33 were included, covering 6417 patients. Simultaneous resection was associated with shorter length of stay (DR: -3.48 days [95% confidence interval {CI}: -5.64, -1.32]), but with a higher risk of postoperative mortality (DR: 0.02 [95% CI: 0.01, 0.02]). There was no difference between groups for blood loss (risk difference [RD]: -141.38 ml [95% CI: -348.84, 66.09]), blood transfusion (RD: -0.06 [95% CI: -0.14, 0.03]) and general complications (RD: 0.01 [95% CI: -0.06, 0.04]). The longest operating time in staged surgery was not statistically significant (RD: -50.44 min [95% CI: -102.38, 1.49]). Regarding overall survival, there is no difference between groups (hazard ratio: 0.88; 95% CI: 0.71-1.04). Patients must be well selected for each strategy. Simultaneous approach to patients at high surgical risk should be avoided due to increased perioperative mortality. However, when the patient presents a low surgical risk, the simultaneous approach reduces the hospital stay and guarantees long-term results equivalent to staged surgery.