Importance of calf vein thrombophlebitis

Fifty-four patients with phlebogram-proven deep vein thrombophlebitis limited to the tibial and popliteal veins were studied for evidence of pulmonary embolism, both symptomatic and silent. All but two patients were symptomatic of either phlebitis or embolism. Pulmonary embolism, as judged by lung scan defects with V-Q imbalance, changing serial scans, or positive pulmonary angiograms were found in 50%. Popliteal thrombi had an embolism incidence of 66%, whereas tibial thrombi had a 33% incidence. Emboli from the popliteal veins were more extensive than were tibial emboli. Forty-five percent of all emboli were silent. Bilateral phlebitis was accompanied by a 75% incidence of pulmonary embolism. Emboli from tibial veins were minor in five of nine instances, but three instances involved 20% or more of total lung volume and one involved over 40% of total lung volume. These results support the belief that popliteal thrombophlebitis merits anticoagulant therapy. They also suggest caution in the management of tibial vein phlebitis. Objective tests are recommended to monitor for pulmonary embolism and for propagation of the thrombus before deciding to withhold anticoagulants in tibial thrombophlebitis.