Pulmonary Embolism Found to Be Often Unrelated to DVT
Pulmonary embolism may not originate from pelvic or proximal lower extremity veins
THURSDAY, Oct. 22 (HealthDay News) -- In patients with pulmonary embolism, only a few have deep venous thrombosis (DVT) of the pelvic or proximal lower extremity veins, suggesting that pulmonary embolism originates in the lungs, according to a study in the October issue of the Archives of Surgery.
George C. Velmahos, M.D., of Massachusetts General Hospital and Harvard Medical School in Boston, and colleagues studied 247 trauma patients who underwent computed tomographic pulmonary angiography with computed tomographic venography of the pelvic and proximal lower extremity veins between 2004 and 2006.
The researchers found that 46 patients (19 percent) had a pulmonary embolism and that 18 patients (7 percent) had DVT, but observed that only seven patients with pulmonary embolism also had DVT. They also found that 18 of the pulmonary embolisms were central (main or lobar pulmonary arteries) and that 28 of them were peripheral (segmental or subsegmental branches).
"To our knowledge, this study is the first to doubt the traditional belief that pulmonary embolism originates from pelvic and proximal lower extremity veins," the authors conclude. "We propose that many pulmonary embolisms form primarily in the lungs and that the risk-benefit ratio of vena cava filters should be reconsidered. As computed tomographic venography becomes more popular and accurate, this issue will be further explored, and it may be revealed that (not surprisingly) we have been preaching and practicing the wrong dogma for years."