Preoperative or postoperative deep-vein thrombosis?

The incidence of deep-vein thrombosis as detected by the 125I-fibrinogen test and confirmed by phlebography was 32% in a high-risk group of patients admitted to hospital more than 4 days before operation. 62% of these thrombi were established before operation. Patients with malignant disease and those receiving preoperative intravenous nutrition were particularly prone to this complication. Recognition that asymptomatic thrombosis may be present before operation helps to clarify many of the enigmatic aspects of this condition, and has important implications for the interpretation of the results of clinical trials of prophylaxis. The condition should be suspected in patients transferred for surgery from medical wards, and prophylactic measures should be commenced at the time of admission in high-risk patients.