Incidence of pulmonary embolism in the course of thrombophlebitis of the lower extremities

Abstract

A prospective study of fifty-two consecutive patients with thrombophlebitis of the lower extremity was carried out utilizing objective examinations to diagnose both the phlebitis and pulmonary embolism. Venography was an accurate means of identifying acute phlebitis. Fifty-two per cent of the patients with proved thrombophlebitis showed objective evidence of pulmonary embolism by lung scan technics including perfusion and ventilation scans. Serial perfusion lung scans materially improved the diagnostic accuracy of scanning technics. By utilizing all of the available lung scan technics the need for pulmonary angiography was decreased. Pulmonary emboli occurred frequently from clots at all sites in the lower extremity, including the tibial veins. The evidence suggests that the untreated clot tends to extend up the leg, giving off emboli intermittently as it goes. The severity of embolism was almost as great in silent as in symptomatic embolism and in popliteal phlebitis as in iliac phlebitis in this series. Seventy-five per cent of the emboli were silent. Treatment with heparin was the mainstay of therapy. Dose-related results showed that 20,000 U of heparin per day provided 89 per cent protection against further embolization. Thrombectomy in iliofemoral phlebitis was found to be effective when the clot was not adherent to the vein wall. Ligation of the superficial femoral vein was utilized to prevent late emboli and late development of a valveless recanalized vessel. No postoperative emboli occurred.