Pulmonary embolism after insertion of a Greenfield filter

This report describes a case in which a patient had a Greenfield filter placed at the time of diagnosis of deep vein thrombosis (DVT) when he was asymptomatic for pulmonary embolism. Later in the patient's hospital course, a typical clincal picture of pulmonary embolism developed. The issues examined in this report include: (1) the incidence of asymptomatic pulmonary embolism; (2) the value of the baseline ventilation perfusion (VQ) lung scan for the diagnosis of DVT; and (3) the value of an echocardiogram in diagnosing pulmonary embolism. It appears reasonable that patients in whom DVT is diagnosed undergo baseline VQ scanning. This procedure would prevent the misdiagnosis of a new pulmonary embolism while the patient is on anticoagulation therapy and possibly avoid unnecessary invasive diagnostic procedures. The case described demonstrates the usefulness of the echocardiogram and a transthoracic echo in the diagnosis of pulmonary embolism. It also points out the surprisingly high incidence of silent pulmonary embolism in patients in whom DVT is diagnosed.