Pulmonary embolism in acute iliofemoral venous thrombosis.

Serial perfusion lung scanning and chest radiography were used to study the incidence of pulmonary embolism in patients with acute iliofemoral venous thrombosis. The efficacy of conventional anticoagulation and surgical thrombectomy in controlling embolism and the risk of creating emboli during thrombectomy were also evaluated. Lung scans obtained on admission in 49 patients were normal in 37 per cent, inconclusive in 18 per cent and positive for embolism in 45 per cent of the patients. Symptoms suggestive of embolism were present in only 24 per cent of the patients and correlated poorly with lung scans. Massive embolism was present in only two patients. Additional, usually asymptomatic, emboli developed within one month in 21 per cent of 29 patients treated conservatively with anticoagulation alone and in 20 per cent of 20 patients having acute thrombectomy combined with a temporary arteriovenous fistula and systemic anticoagulation. Only one conservatively treated patient required caval interruption. Pulmonary embolism, usually of minor degree, is thus present in nearly every other patient with acute iliofemoral venous thrombosis. Anticoagulation alone or in conjunction with thrombectomy and arteriovenous fistula in most cases effectively prevents further embolization and the risk of creating additional emboli by the surgical procedure is insignificant.