Thrombophilic Abnormalities in Patients With or Without Pulmonary Embolism Following Elective Spinal Surgery

Abstract

Background: Significance of the thrombophilic abnormalities in development of venous thromboembolism (VTE) has been studies with total hip arthroplasty and acute traumatic spinal cord injury. However, their role as risk factors for VTE in elective spinal surgery remains to be determined. Questions/Purposes: To determine the role of thrombophilic abnormalities in the development of pulmonary embolism (PE) following elective spine surgery. Methods: Case and control groups were created in patients who had undergone elective spinal surgery for degenerative conditions. The PE group comprised 12 patients whose post-operative course was complicated by development of PE. The control group included 12 patients with an uneventful post-operative course. Demographic data including age, gender and surgical procedures were matched between the PE group and the control group. Both groups were evaluated for thrombophilic and hypofibrinolytic risk factors at 3 months post-operatively or later. Blood tests were performed to measure fasting serum homocysteine, antithrombin III, and protein C. Molecular genetic testing was conducted for detection of the plasminogen activator inhibitor-1 4G/4G, and prothrombin 3 UTR gene mutations. Results: Heterozygous mutation (G20201A) of prothrombin was detected in two patients (16.7%) in the PE group, whereas no such mutation was noted in the control group. Plasminogen activator inhibitor-1 4G/4G homozygous mutation was seen in three in the PE group and two in the control group. Of homocysteine, antithrombin III and protein C, only one patient in each group showed abnormal levels of homocysteine. In total, there half of the patients in the PE group had at least one thrombophilic abnormality, whereas three (25%) patients showed such abnormality in the control group. Conclusion: These findings suggest the involvement of thrombophilic abnormalities, especially the heterozygous G20201A mutation, in the development of PE in patients undergoing elective spinal surgery.