Perioperative Changes of Blood Coagulation by a Thromboelastograph in Patients Undergoing Clipping of Cerebral Aneurysms

Kim, Young Jae; Park, Gee Nam; Yoon, Sang Yeoul; Cheong, Soon Ho; Choe, Young Kyun; Park, Jin Woo; Shin, Chee Mahn; Park, Ju Yuel

Abstract

BACKGROUND: Patients undergoing brain surgery have a high risk of developing a number of perioperative coagulation disorders. Anesthesia and surgical stress may affect blood coagulation and fibrinolysis. The aim of this study was to evaluate perioperative changes in hemostatic parameters of patients undergoing clipping of cerebral aneurysms with a thromboelastograph (TEG) in combination with simple laboratory tests.
METHODS
Twenty adult patients who had cerebral aneurysms and no history of coagulation disorders were studied. Isoflurane and N2O were used for all anesthetic proceedings. Preanesthetic, intraoperative (after skin incision and after clipping of cerebral aneurysms) and postanesthetic measurements included a TEG and simple laboratory tests. The TEG variables included r time (reaction time for clot formation), k time (clot formation time), alpha angle (rate of clot growth), MA (maximal amplitude of clot strength) and LY30 (fibrinolytic index).
RESULTS
In simple laboratory tests, prothrombin time (PT) and partial thromboplastin time (PTT) at intraoperation and postanesthesia were longer than those at preanesthesia (p < 0.05). In the TEG, r and k time at intraoperation and postanesthesia were shorter than those at preanesthesia (p < 0.05). However the alpha angle at intraoperation and postanesthesia was longer than that at preanesthesia (p < 0.05). There was no significant difference in MA and LY30 except an increase in MA after the skin incision (p < 0.05) compared to the MA at preanesthesia.
CONCLUSIONS
These results indicate a general hypercoagulability during and after a cerebral aneurysms operation in terms of TEG, although, the level of the PT and PTT can be at the upper limits within normal. Therefore perioperative use of coagulants in cerebral aneurysms may increase the risk of a thromboembolism because of accelerating blood coagulability. By early intraoperative and postoperativeevaluation of the hemostatic abnormality with a TEG, appropriate measures might be initiated to prevent postoperative complications due to hypercoagulability.