Influence of open surgical and endovascular abdominal aortic aneurysm repair on clot quality assessed by ROTEM® test.

Introduction/aim: The disturbances in hemostasis are often in open surgical repair (OR) and endovascular repair (EVAR) of an abdominal aortic aneurysm (AAA). These changes may influence the perioperative and early postoperative period inducing serious complications. The aim of this study was to compare the impact of OR and EVAR of AAA on clot quality assessed by rotational thromboelastometry (ROTEM®) tests.

Methods: The study included 40 patients who underwent elective AAA surgery and were devided into two groups (the OR and the EVAR group - 20 patients in each group). The ROTEM ® test was performed in 4 points: point 1 - 10 min before starting anesthesia in both groups; point 2 - 10 min after aortic clapming in the OR group and 10 min after the stent-graft trunk release in the EVAR group; point 3 - 10 min after the releasing of aortic clamp in the OR group and 10 min after stentgraft placement and releasing the femoral clamp in the EVAR group; point 4 - one hour after the procedure in both groups. Three ROTEM® tests were performed as: extrinsically activated assay with tissue factor (EXTEM), intrinsically activated test using kaolin (INTEM), and extrinsically activated test with tissue factor and the platelet inhibitor cytochalasin D (FIBTEM). All tests included the assessment of the maximum clot firmness (MCF) and the platelet component of clot strength was presented as maximal clot elasticity (MCE).

Results: No significant difference in age, gender and diameter of AAA between groups was found. The time required for the procedure was significantly longer and loss of blood was greater in the OR group than in the EVAR group (p < 0.001). The significant deviation of MCF values in EXTEM test was found mainly in the point 3 (p ≤ 0.004) with significant difference between groups (p < 0.001). A significant difference of MCF values in INTEM test between groups was found in the points 3 and 4 (p < 0.001), which were dose-dependent by heparin sulfate. The MCF values in FIBTEM test were more prominent in the OR group than in the EVAR group without significant difference. The significant changes of MCF values in the FIBTEM test were found during time in both groups (p < 0.001). The values of MCE were lower in both groups, but without significant changes and difference between groups (p = 0.105).

Conclusion: The disorders of hemostatic parameters assessed by ROTEM® tests are present in both the OR and the EVAR groups being more prominent in OR of AAA. Vigilant monitoring of hemostatic parameters evaluated by ROTEM® tests could help in administration of the adequate and target therapy in patients who underwent EVAR or OR of AAA.