Many patients with carotid artery stenosis have received carotid endarterectomy (CEA) for prevention of ischemic stroke. American Heart Association guidelines state that CEA has a proven indication in symptomatic patients with at least 70% stenosis. The procedure is acceptable in patients with 50% to 69% stenosis.

The North American Symptomatic CEA Trial (NASCET) included patients with symptomatic patients with carotid stenosis. Risk of ipsilateral stroke for medically treated patients was 26% at 2 years. In the CEA group, stroke risk was 9%.

There are surgical risks to CEA. Surgical complications at 30 days in the NASCET trial included death (1.1%), disabling stroke (1.8%) and non-disabling stroke (3.7%). Almost 10% of patients had perioperative wound complications and 9% had cranial nerve injury.

Carotid angioplasty plus stent is available as an alternative treatment. However, it is dangerous to put a stent in patients with soft plaque, fresh thrombi or aortic plaque. This is because the stent can dislodge the atheromatous plaque and cause cerebral embolism. These patients should receive CEA instead of carotid stenting.

There is controversy over how to treat patients who require both CEA and coronary artery bypass graft. There is an operative risk of cerebrovascular attack, myocardial infarction and death.

Off-pump coronary artery bypass graft can reduce risk of neurologic complications. In the reported experience of investigators at the National Cardiovascular Center in Osaka, off-pump procedure had a 0% risk of neurologic complications. In comparison, on-pump procedures had a 6.4% risk. Therefore, the off-pump procedure is very useful in reducing the total risk of patients who need to have both bypass and CEA.

In patients with severely impaired cerebral blood flow, bypass surgery may be very useful to increase blood flow and prevent recurrent stroke. Now in Japan, researchers are conducting a controlled, randomized study of extracranial-intracranial (EC-IC) bypass surgery.

The Japan EC-IC Bypass Trial (JET) includes 280 patients randomized to either surgery or medical therapy. The patients are followed for 2 years to assess rates of stroke, death, disability and uncontrollable transient ischemic attacks.

The JET study includes patients with minor stroke or transient ischemic attack due to occlusion or severe stenosis of the internal carotid artery or medial cerebral artery. The study excludes patients with cervical internal carotid artery stenosis. The patients must be less than 73 years old and the stroke or transient ischemic attack must have occurred within 3 months of the trial. Baseline cerebral blood flow must be severely impaired (less than 80% of normal value).

Interim results at 1 year show that EC-IC bypass is effective in preventing stroke recurrence. Because of this promising data, investigators hope and believe that bypass surgery will become an accepted treatment for ischemic stroke.