California doctors have found inserting a stainless steel tube into a blood vessel in the leg may eliminate the need for major surgery for some people whose chest artery has ballooned into a life-threatening aneurysm.

The technique is similar to one already being developed by other researchers to expand blood vessels narrowed by heart disease using an expandable mesh tube.But the latest round of research, conducted at Stanford University's School of Medicine, involves using custom-designed tubes to help close the ballooning portion of a blood vessel.

If all goes well, blood clots forming in the mesh seal the opening of the aneurysm, reducing the risk that the ballooned portion of the wall will rupture, according to a report by the team, led by Dr. Michael Dake.

The report in Thursday's New England Journal of Medicine said the tubes, known as endovascular stent-grafts, have been placed in 33 patients.

The technique was successful in all but three patients, two of whom died from multi-organ failure. The third needed further surgery.

But the researchers stressed that more tests and continued monitoring of the patients is needed to determine if the technique provides a truly viable, long-term method for treating aneurysms.

Chest aneurysms are extremely dangerous. When one pops, it is usually fatal because that blood vessel carries most of the blood to the rest of the body. As a result, only about one in 10 people with the condition live for more than five years unless they undergo surgery.