DEEP VENOUS THROMBOSIS AND PULMONARY-EMBOLISM AFTER MAJOR RECONSTRUCTIVE OPERATIONS ON THE SPINE - A PROSPECTIVE ANALYSIS OF 317 PATIENTS

We performed a prospective study of 317 patients in order to determine the prevalence of deep venous thrombosis after reconstructive operati ons on the spine; 126 of the patients were examined with duplex ultras ound assessments of the lower extremities to ensure that no asymptomat ic thrombi were being missed. Thigh-high stockings and sequential pneu matic compression of the lower extremities were used, in all patients, for prophylaxis against venous thrombosis. No antiplatelet agents or anticoagulant medications were administered. There was no evidence of thrombosis on any of the duplex ultrasound studies. Subsequently, veno us thrombosis developed and was treated successfully in one of the 126 tested patients and in one of the 191 untested patients, and a fatal pulmonary embolus developed in one of the untested patients. The over- all clinical prevalence of thrombotic complications was 0.9 per cent ( three complications in 317 patients). All three of the patients who ha d clinical evidence of thrombosis had had an anterior lumbar procedure because of a degenerative disorder or trauma; however, we could not p rove that this approach or these diagnoses were significant risk facto rs for thrombosis (p < 0.05). While it is possible that some thrombi m ay have escaped both clinical and ultrasonic detection, such thrombi a pparently were not enough of a danger to warrant the use of intensive prophylactic procedures that are associated,vith more risk. On the bas is of this prospective study, therefore, we think that routine screeni ng for the detection of asymptomatic thrombosis in patients who have h ad a procedure on the spine is unwarranted.