Editor's Choice – A Rotational Thromboelastometry Driven Transfusion Strategy Reduces Allogenic Blood Transfusion During Open Thoraco-abdominal Aortic Aneurysm Repair: A Propensity Score Matched Study

Objective: Open repair of thoraco-abdominal aortic aneurysm (TAAA) is a challenging procedure, associated with high rates of peri-operative bleeding and blood product transfusions. A large intra-operative volume transfusion has been associated with higher in hospital mortality and prolonged mechanical ventilation. A propensity score matched study was carried out to assess whether the introduction of a rotational thromboelastometry (ROTEM) based transfusion strategy reduces allogenic blood transfusion and affects morbidity in patients undergoing open TAAA repair. Methods: All patients undergoing open TAAA repair at the San Raffaele Scientific Institute between 2009 and 2017 were included. Until 2016, a protocol based on estimated blood loss and conventional coagulation tests was used. After March 2016 a ROTEM guided transfusion protocol was developed and adopted. To account for selection bias, propensity score matching was performed. Results: Five hundred and forty-seven consecutive patients were included. After propensity score matching, 77 patients in the ROTEM algorithm group were successfully matched with 77 patients in the standard algorithm group. Patients managed with ROTEM received fewer red blood cells units (3.5 [range 0–11] vs. 4 [range 0–17]; p = .026) and a lower volume of fresh frozen plasma (286 ± 496 vs. 2,050 ± 1,120; p < .001). In addition, fewer patients received fresh frozen plasma (35% vs. 97%; p < .001). Patients in the ROTEM group showed a significant decrease in the occurrence of pulmonary complications (44% vs. 83%; p = .01). Cost analysis showed a relevant reduction of per-patient expense after the introduction of ROTEM (€834 ± €577 vs. €1,285 ± €851; p < .001) Conclusion: A ROTEM guided transfusion strategy significantly limited the quantity of transfused blood products during open TAAA repair, improving clinical outcomes while reducing costs, allowing for better resource distribution in a setting where blood loss is relevant.