HEMOSTATIC CHANGES DURING SURGERY FOR PRIMARY BRAIN-TUMORS

Objective - Primary brain tumours may be associated with coagulation d isorders which can pose intraoperative and postoperative management di fficulties. The aim was to evaluate the coagulation profile of patient s with brain tumours undergoing surgery using thromboelastography (TEG ) in combination with simple laboratory tests. Methods - Fifty adult p atients with primary brain tumours larger than 4 cm in maximum diamete r and no history of coagulation disorders were studied in a prospectiv e, observational manner over a one year period. Preoperative, intraope rative, and postoperative measurements included haemoglobin concentrat ion, platelet count, prothrombin and partial thromboplastin times, fib rin(ogen) degradation product concentration, D-dimer concentration, an d TEG. Results - Eleven patients (22%) had abnormal intraoperative TEG s, of whom six (12%) subsequently developed haematomas requiring surgi cal evacuation. The coagulopathy seemed to be hyperfibrinolysis in two cases (4%) and disseminated intravascular coagulation in four (8%). T here was no preoperative difference in reaction time (R time) for clot formation between the non-haematoma and haematoma groups(mean 11.44 ( SD 3.42) v 12.33 (2.50) min, P = 0.46). However, when other preoperati ve indices were compared, in the non-haematoma group, K time (time to reach a clot amplitude of 20 mm) was shorter (6.72 (2.15) v 10.56 (3.5 0) min, P=0.001), rate of clot growth ((a) over circle) was faster (43 .67 degrees(7.53) v 27.11 degrees (5.42), P<0.0001) and maximum amplit ude of clot strength (il IA) was greater (52.64 (7.85) v 40.33 (6.59) mm, P< 0.001). Intraoperatively, R time was significantly shortened in the non-haematoma group, (7.67 (1.78) min, P<0.0001) unlike the haema toma group (10.67 (1.58) minutes, P=0.11). Conclusions - Although thes e results indicate a general hypercoagulability during brain tumour su rgery in certain cases, a predisposition towards hypocoagulability may exist even before surgery, detectable only when the physical characte ristics of clot formation are studied by TEG. Judicious replacement of clotting factors, platelets, and antifibrinolytic agents should be co nsidered intraoperatively if the TEG is abnormal, without waiting for laboratory test results.