Study design: Adult spinal surgery patients were studied prospectively to determine the incidence of subclinical deep venous thrombosis. An overlapping group of patients was reviewed retrospectively for symptomatic thromboembolism.
Objectives: To determine the incidence of symptomatic and asymptomatic thromboembolism in spinal surgery patients.
Summary of background data: Although thromboembolic complications are known to occur after spinal operations, there are limited published data on the incidence of pulmonary embolus or deep venous thrombosis after major spinal surgery.
Methods: One hundred sixteen adult spinal surgery patients were examined with duplex ultrasound to determine the incidence of deep venous thrombosis. Seventy-three of these patients also underwent lung perfusion scans to look for subclinical pulmonary embolism. A retrospective review was conducted of symptomatic thromboembolic complications occurring in a 2-year period at the authors' center. Three hundred and eighteen major spinal reconstructive procedures were performed during the period reviewed, which included the period of the prospective study and therefore the patients of the prospective group. Thigh-length compression stockings and pneumatic compression leggings were used for prophylaxis in all patients.
Results: One patient had an asymptomatic iliac vein thrombosis, and seven patients had symptomatic pulmonary embolism (2.2%). Six of the symptomatic pulmonary emboli occurred after combined anterior/posterior spinal fusions (6%), whereas only one occurred after posterior decompression and fusion (0.5%).
Conclusions: Duplex ultrasound appeared insensitive for diagnosing clots before embolization in this patient group. Simple mechanical prophylaxis for thromboembolism, which may be adequate for patients undergoing posterior procedures, may not be as protective for patients undergoing combined anterior/posterior spine surgery.