CALF VEIN THROMBI ARE NOT A BENIGN FINDING

BACKGROUND: Currently, there is no consensus in the literature regardi ng which patients with calf vein thrombi are at high risk for proximal propagation. This study examined patients with isolated calf vein thr ombi with serial duplex scans in order to identify risk factors that w ould predict outcome. PATIENTS AND METHODS: Between May 1989 and Novem ber 1994, 288 patients were identified with isolated calf vein thrombi . One hundred ninety-two of them had sequential scans performed. RESUL TS: Fifty-three (28%) of the 192 patients had propagation of their ini tial thrombi. The most proximal level of propagation was the popliteal vein in 11 patients, the superficial femoral vein in 5, the common fe moral vein in 5, adjacent tibial or soleal veins in 24, adjacent solea l veins alone in 7, and the lesser saphenous vein in 1. Three patients whose thrombi propagated had free-floating thrombus tips in the large veins of their thighs. Symptoms, prophylaxis, and risk factor analysi s comparing those patients whose thrombi propagated to those whose thr ombi did not found no statistically significant prognostic value. Sing le or multiple calf vein thrombi did not predict propagation. Of the 2 3 patients treated with heparin, only 3 had thrombus propagation. None of these reached the level of the knee (including popliteal vein). CO NCLUSIONS: The natural history of distal lower extremity thrombosis do es not appear to be as benign as previously believed.