Leg Clots May Not Travel to Lungs

Research refutes danger from deep vein thrombosis, but experts urge caution

By Amanda Gardner
HealthDay Reporter

Related Encyclopedia • Alzheimer's Disease • Aneurysms • Angina Pectoris • Angiogram More... Related Healthscout Videos At-Home Stroke Rehab Erectile Dysfunction Drugs Do More Than Arouse New Life for Dying Hearts Filling Cartilage Potholes More... Related Animations • Alzheimer's Disease Video Animation • Angioplasty • Coronary Bypass Surgery • Erectile Dysfunction More... Related Drug Information • Accupril • Actonel • Altace • Avapro More... Related News Articles • Response Team Reduces Rate of Cardiac Arrests: Hospital • Many Americans Don't Even Know They're Fat • Prescription Drug Use Rising in U.S., CDC Reports • Seniors Get Boost From Bad News About the Young More...

TUESDAY, Oct. 20 (HealthDay News) -- New research raises doubts about the long-held medical dogma that dangerous blood clots in the lungs, known as pulmonary emboli, originate from clots in the deep veins of the legs or other parts of the lower body, which then break up and travel up through the body.

A study appearing in the October issue of the Archives of Surgery found that 85 percent of trauma patients with pulmonary emboli showed no sign of deep vein thrombosis, or blood clots in the lower extremities.

Text Continues Below

---

The lead author of the study, Dr. George Velmahos, chief of the division of trauma, emergency surgery and surgical critical care at Massachusetts General Hospital and professor of surgery at Harvard Medical School in Boston, said the findings also cast doubt on the use of filters to prevent the clots from traveling.

But an outside expert said the findings need to be received cautiously, at least for now.

"I think it's an interesting report. I wouldn't call it a bombshell", said Dr. Jack Ansell, chairman of the department of medicine at Lenox Hill Hospital in New York City. "I think this study by no means answers this question or reverses the original concept that most pulmonary embolisms originate as venous thrombosis [blood clots] in the deep veins of leg or sometimes in pelvis or abdomen."

According to Velmahos, the concept of clots in the lungs originating as clots in the legs has never been challenged, despite evidence in the literature that some patients suffering from pulmonary embolism did not show signs of having had a blood clot in the lower extremities.

For this study, Velmahos and co-authors looked back over medical records of 247 trauma patients who had undergone CT pulmonary angiography and CT venography.

Among 46 patients with PE, only 7 also had DVT, or 15 percent.

There are possible explanations, the team said. It's possible that the entire original clot detached itself, leaving no traces. However, cadaver studies suggest that only a part of the leg clot breaks away, and a remnant is typically left behind. Or it could be that small clots exist and were not picked up by imaging techniques or even that the clots start in the upper extremities, which are not routinely examined.

Page:  1 | 2 | Next >>