March 20, 1998
MEDIA CONTACT: Karen Infeld
PHONE: (410) 955-1534
Vascular surgeons at Johns Hopkins are participating in a nationwide test of a procedure that uses 3-D images and a metal-supported cloth tube to repair stretched and weakened abdominal arteries before they burst and kill.
The tube, called a stent graft, is implanted in the abdominal aorta -- the main artery supplying blood to the lower body -- through a small incision in the groin. Blood then passes through the stent graft, taking pressure off the large and weak aorta, and reducing or eliminating the risk of rupture and death.
"This seems to be a safe and effective alternative to major surgery," says G. Melville Williams, M.D., chief of vascular surgery and lead investigator for the trial. "Previous studies show patients are out of the hospital quicker, have much less pain and return to pre-operative functioning much faster. Patients usually are discharged on the second day after the procedure, provided tests show the aneurysm is excluded from circulation."
Called silent killers because they often cause no symptoms, aneurysms occur in more than 5 percent of people age 60 and older. The incidence is higher among smokers, although aneurysms usually occur as the normal wear-and-tear aging process weakens the arterial wall. Sometimes they result from trauma or acute or chronic infections. They can be fatal if they leak or rupture.
About 75 percent of aneurysms go undiagnosed unless found unexpectedly during physical exams or picked up on X-rays taken for unrelated reasons.
In the current study, at 16 centers nationwide, physicians take 3-D computed tomography images of the abdomen to determine the exact anatomy of the aneurysm. If physicians feel the stent graft is suitable, it is inserted through an opening in the groin's femoral artery and threaded into the aneurysm using fluoroscopy, or X-ray imaging. The stent's metallic frame is flexible at cold temperatures but stiff at body temperature. This enables the cloth support to expand to fill the necessary space, excluding the aneurysm.
Traditional treatments for abdominal aortic aneurysms require extensive surgery to sew a similar but unsupported cloth tube inside the ballooning aorta.
Williams is accepting 15 patients for the Hopkins study, which is nearly complete. He anticipates that the new treatment will be available once the study is completed. For more information or to volunteer, call 410-955-5165.
The clinical trial is sponsored by Meadox Medicals Inc. (a division of Boston Scientific Corp.), manufacturers of the stent.