Paradoxical emboli from calf and pelvic veins in cryptogenic stroke.

PURPOSE: The increased prevalence of patent foramen ovale in patients with cryptogenic strokes suggests the occurrence of paradoxical embolism. The identification of deep venous thromboses (DVTs) in this population would strengthen this hypothesis. The purpose of this study was to image the subdiaphragmatic venous system in a cohort of patients with cryptogenic strokes.

MATERIALS AND

METHODS

In 37 patients with cryptogenic brain ischemia and interatrial communication, duplex studies of calf, popliteal, and femoral veins, and magnetic resonance imaging venograms of the pelvis veins were performed.

RESULTS

In 10 patients, DVTs were diagnosed that were considered to be the cause of cryptogenic brain ischemia on probable (n = 6) or possible (n = 4) bases. In these patients, the median time from stroke to DVT was 3.25 days. In 5 of these 10 patients, DVTs did not involve popliteal and femoral veins, areas thought most important to pulmonary embolism, but instead were isolated to calf or pelvic veins. Although none of these 10 patients had abnormal blood hypercoagulation tests, 8 of the 10 did have clinical conditions suggesting predisposition to developing DVTs, such as concomitant neoplasms or pulmonary embolism.

CONCLUSIONS

Increased evidence for paradoxical embolism may emerge when diagnostic strategies use multiple imaging methods and evaluate a broad extent of the subdiaphragmatic veins.