Post-operative thromboembolism in neurosurgery

Summary This study compares the safety and effectiveness of two methods for the prophylaxis of post-operative thromboembolism in neurosurgical patients: A: low-dose heparin (5,000 IU×2 s.c.) started preoperatively and continued daily for one week post-operatively, and B: per-operative electrical calf muscle stimulation with groups of impulses plus post-operative dextran infusions every other day for one week.Neurosurgical patients aged 40 years or more with normal laboratory coagulation values and operated under general anaesthesia were included. The 125:I-fibrinogen uptake test (FUT) was used for screening and phlebography for verification of deep venous thrombosis (DVT). 122 patients entered the study and 104 completed the prophylactic protocol, 58 in group A and 46 in group B. The two groups were comparable according to pre-operative data and distribution of diagnoses.89 patients completed screening for post-operative DVT. We found an overall incidence of 5/49 (10 percent) DVT in group A and 5/40 (13 percent) in group B, compared to a frequency of 32–50 percent for controls without prophylaxis reported in the literature^{6, 16, 18}. In spite of prophylaxis our patients with intracranial neoplasms and intracranial vascular disease showed a relatively higher incidence of DVT, 4/23 (17 percent) and 4/14 (29 percent) respectively, compared to patients with spinal diagnoses 2/25 (8 percent). In combination with cranial diagnoses paretic lower limbs meant an apparent risk factor, 4/7 (57 percent). However, paretic limbs appearing in cases with spinal disorders did not predetermine an unsuccessful prophylaxis, 2/14 (14 percent).Blood loss, transfusion requirements and post-operative complications did not differ significantly between the two prophylactic groups.It is concluded that both methods reduce the incidence of post-operative DVT in neurosurgical practice and that they can be used with safety. However, the basic mechanisms behind thromboembolism following parenchymatous brain lesions ought to be studied further to enable a better understanding of the thromboembolic complications and further improvement of the prophylaxis.