Blood loss and outcomes after resection of colorectal liver metastases

Background: The influence of intraoperative blood loss (IBL) on long-term outcomes of patients undergoing liver resection for colorectal cancer liver metastases (CRLM) remains not well defined. Materials and methods: A total of 433 patients who underwent curative-intent hepatic resection for CRLM between 2000 and 2013 at Johns Hopkins were identified. Demographics, IBL data, and long-term outcomes were collected and analyzed. Clinicopathologic predictors of IBL and the association of IBL and outcomes were assessed. Results: The median patient age was 54 y (interquartile range, 44-64), most patients were male (58.9%; n = 255). At surgery, the median IBL was 400 mL (range, 10-5100 mL). Two-hundred eighty-seven patients (66.3%) had an IBL of >250 mL. Factors associated with increased IBL (>250 mL) on multivariate analysis were male sex (odds ratio [OR], 2.62; 95% confidence interval [CI], 1.68-4.09; P <0.001), tumor size >3 cm (OR, 1.88; 95% CI, 1.18-2.99; P = 0.008), and major hepatic resection (OR, 3.08; 95% CI, 1.92-4.92; P <0.001). At a median follow-up time of 30.6 mo, the median survival times were 70.5, 56.4, and 36.9 mo for IBL 1000 mL, respectively (P = 0.004). IBL >250 mL remained an independent prognostic factor of overall survival in multivariate analysis (hazard ratio, 1.41; 95% CI, 1.01-1.97; P = 0.04) after adjusting for other factors including the receipt of blood transfusion. Conclusions: The magnitude of IBL during CRLM resection was related to biologic characteristics of the tumor and the extent of surgery. Increased IBL during CRLM resection was an independent prognostic factor for worse patient survival. Furthermore, a dose-response relationship between increasing IBL and worsening survival was evident.