S2871 Evaluating the Efficacy and Safety of Hypovolemic Phlebotomy in Patients With Liver Surgery: A Systematic Review and Meta-Analysis

Introduction: Significant blood loss is common in major liver surgery, heightening the need for transfusions and increasing postoperative risks. Hypovolemic phlebotomy (HP) has surfaced as an effective method to reduce bleeding by decreasing central venous pressure, all without the need for volume replacement. This meta-analysis examines the safety and effectiveness of HP in reducing blood loss during liver resection. Methods: From inception until March 2025, a comprehensive literature review was performed using PubMed, Cochrane Central, and ScienceDirect. Risk ratios (RR) and weighted mean differences (WMD) for both categorical and continuous outcomes were aggregated utilizing the random effects model in Review Manager software version 5.4.1. A sensitivity analysis, which excluded one study at a time, was executed to evaluate heterogeneity. The assessment of quality was conducted using the Cochrane risk of bias tool and the Newcastle-Ottawa scale. Results: This meta-analysis includes 8 studies with a total of 1,901 patients. In the HP group, blood loss is significantly lower compared to the placebo group (MD: -440.13 mL; 95% CI: [-756.20, -124.07]; P = 0.006). The HP arm also sees a notable decrease in hospital stay length (MD = -15.98 days; 95% CI: [-21.36, -10.60]; P < 0.01). Other measures, including red blood cell transfusion (RR = 0.60; 95% CI:[0.35, 1.04]; P = 0.07), major complications (RR = 1.40; 95% CI: [0.93, 2.13]; P = 0.11), and overall complications (RR = 1.15; 95% CI: [0.86, 1.53]; P = 0.35), show comparable results between both groups. Conclusion: HP greatly minimizes blood loss during liver resection surgery and shortens hospital stays for patients while avoiding an increase in transfusion requirements or complications, demonstrating its safety and efficacy. Additional research could further enhance its implementation in clinical settings.