April 30, 2007 — Carotid stenting can be performed on any age patient, but should be undertaken with caution and skill for patients 80 years and older, as well as done safely in experienced centers, according to a study in the May 2007 issue of the Journal of Vascular Surgery.
Peter L. Faries, M.D., site chief in the division of surgery at Cornell University, Weill Medical School and chief of endovascular surgery at New York Presbyterian Hospital, at Columbia University, both in New York City, says his study suggests that patients older than 80 are more likely to have vascular changes that occur with age, predisposing them to increased risks for complications, including strokes.
"When vascular surgeons are determining whether elderly patients should undergo stenting or carotid artery surgery (CAS), or carotid endarterectomy (CEA), evaluation of major blood vessel characteristics is critical for minimizing operative risk," said Dr. Faries.
Study researchers reviewed vascular characteristics in 135 CAS patients who were undergoing carotid artery stenting to determine the incidence and complications by age.
Thirty-seven of the patients were 80 or older. In this subgroup, there was an increased incidence of unfavorable arch elongation, arch calcification, common carotid or innominate artery orgin stenosis, common and internal carotid artery tortuosity and treated lesion stenosis. No significant difference was found for treated lesion calcification or length.
Of these elderly patients, perioperative cerebral vascular accidents occurred in four; myocardial infarction (MI) in three; and death in one, secondary to a hemorrhagic stroke. The combined stroke, MI and death rate was 11 percent for those older than 80; 1 percent for those younger than 80; and 3.7 for the entire patient population.
"Older patients' anatomy increases the technical difficulty of performing CAS and is associated with complications during the procedure," said Dr. Faries. "Although our small number of perioperative events does not allow us to determine a direct relationship to specific anatomic characteristics, unfavorable anatomy does warrant serious consideration during evaluation for CAS in elderly patients."
Dr. Faries added that increasing use of endografts to treat abdominal aortic aneurysms (AAA) has prompted the need for improved postoperative imaging and surveillance. Patients benefit from decreased morbidity with endovascular aneurysm repair (EVAR) as compared to open AAA repair, however long-term outcome of stent repair has yet to be determined.
Endoleaks may lead to aneurysm rupture after endograft repair, added Dr. Faires. Healing of endografts is usually evaluated by obtaining serial helical CT angiography (CTA) to identify endoleaks, graft migration, thrombosis and structural failure; however it is not 100 percent effective at identifying endoleaks and predicting aneurysm rupture.
Other imaging modalities have been studied, including three-dimensional CTA with volumetric analysis, contrast enhanced duplex ultrasound, cine MRA and explant analysis. In vitro and large animal models of AAA also have been developed to study the pathophysiology and treatment response of aneurysm exclusion.
"To eliminate the risk of AAA rupture, EVAR requires exclusion of the aneurysm from arterial perfusion," said Dr. Faires. "Ultrasound duplex serves as a useful adjunct to CTA, particularly in patients with renal failure, but it has been shown to be less effective at identifying endoleaks when compared to CTA. Both CTA with volumetric analysis and cine MRA are promising due to improved sensitivity to endoleak, but they are not as readily available as CTA and need further comparative investigation.
In addition, in vitro and large animal studies have focused on models of AAA creation and exclusion. Intrasac measurements have been shown to accurately correspond to complete exclusion and to the persistence of endoleaks.
Dr. Faries said all options offer much information about endoleak and sac expansion, but more studies are necessary to determine the best postoperative EVAR surveillance.