Volumetric analysis of aneurysm thrombosis after thoracic endovascular aortic repair predicts postoperative changes in platelet count and coagulation parameters.

BACKGROUND: The aim of this study was to investigate the predictors of blood count changes and coagulation parameters alterations after thoracic aortic endovascular repair (TeVar). METHODS: Fifty patients (41 males, age 72±7 years) submitted between 2007 and 2009 to elective TEVAR for non-dissecting aortic lesions, without major associated surgical procedures, were analyzed. Blood count and coagulation parameters were recorded pre-operatively and daily up to postoperative day 5. The volume of new thrombus formed after TEVAR (TV) was calculated comparing pre- and post-operative computed tomography scans with a semi-automatic method by two independent examiners. Pre- intra-, and postoperative variables, including TV, were tested for a possible effect on changes in laboratory values and transfusion requirements using a stepwise multiple regression model analysis. RESULTS: In the multivariable model, TV and associated surgical procedures were significantly associated with maximum platelets decrease (P=0.021, and P=0.029, respectively), while only TV remained a significant predictor for maximum prothrombin time increase (P=0.003). Maximum aneurysm diameter (P=0.041), procedural time (P=0.027), and TV (P=0.047) were also significant predictors of transfusion requirement. CONCLUSIONS: TEVAR is associated with consumption of platelets and coagulative factors, which seems to be associated with the amount of perioperative aneurysm thrombosis. The latter may also help to predict perioperative transfusion requirement.