Category Archives: Carotid Artery Stenosis

Proximal Protection Alternative for Use During Carotid Artery Stenting

Carotid Artery Stenting by Dr. Amir HaghighatCarotid artery revascularization historically has been achieved by an open surgical technique called carotid endarterectomy. In this approach, the vessel is opened to remove the plaque while the patient is under general anesthesia. Carotid artery stenting is an alternative carotid artery stenosis treatment in which a stent is placed via a catheter inserted through a tiny incision in the groin. During carotid artery stenting there is some risk of embolization of the carotid artery plaque to the brain causing a stroke or mini-stroke. Distal embolization protection filters are deployed downstream from the lesion to capture emboli during the procedure. The filter is then retrieved and removed from the body after stenting is completed to safely remove the debris.

Although this approach has been shown to have a similar efficacy and safety compared to carotid endarterectomy, there are some carotid artery stenoses that are still too high risk for either carotid surgery or carotid stenting with distal filter protection. These stenotic lesions include 99% occlusions that pose a challenge for filter advancement as well as lesions with fresh, mobile thrombus often found in patients with recent stroke or mini-stroke. Other complex lesions in tortuous carotid arteries too tortuous for distal filter placement were felt to be excessively high risk in the past. In these subsets of patients who were previously deemed both too high risk for carotid endarterectomy and extremely complex for carotid artery stenting with distal protection there has been no other revascularization option until a few years ago.

The Mo.Ma device is a proximal protection tool that protects the brain during a carotid artery stenting procedure. The Mo.Ma device includes balloons that are inflated inside the common carotid artery and external carotid artery to act like surgical clamps, preventing any plaque debris that might break off and migrate upstream in the carotid artery to the brain. The stenting procedure is performed while the balloons remain inflated. Distal embolic protection is not required since the inflated balloons prevent flow of debris to the cerebral arteries. After the stenting is completed, the suspended blood is aspirated to filter out any debris, and the balloons are then deflated and removed. The entire procedure takes less than an hour.

Using the Mo.Ma proximal protection device, several patients have been successfully treated by interventional cardiologist Dr. Amir Haghighat at Bay Medical Center in Panama City, FL. Dr. Haghighat treated the first patient in the region in the early part of 2011 after the patient presented with an acute stroke during a heart attack. This patient had multiple underlying illnesses that made him too high risk for surgery. Initially, there was reluctance to offer the patient anything other than medical therapy, especially considering the dense thrombus burden in the carotid arterial lesion. However, the patient continued to have mini-strokes on medical therapy, and this prompted the decision to use the Mo.Ma device when a distal filter would have been too high a risk. Fortunately, the patient did well, and his carotid artery lesion was reduced from 99% occlusion to no residual stenosis and no recurrent strokes or mini-strokes.

Since this patient was treated, several additional patients have been successfully treated with this proximal protection device technique at Bay Medical Center without any periprocedural strokes, mini-strokes or major adverse events.

Carotid Artery Stenosis Treatment Options

Carotid artery stenosis is a significant cause of stroke.  Stroke affects at least 731,000 people in the United States alone, and as many as 50% of strokes may be caused by carotid artery stenosis.  The treatment of carotid artery stenosis is either medical, surgical (carotid endarterectomy) or carotid artery stenting.

Conservative medical therapy

Conservative medical therapy for carotid artery stenosis with lifestyle modifications and pharmacotherapy are recommended as a conservative form of treatment.  Hypertension, smoking, diabetes mellitus and hyperlipidemia should be treated in all patients with these risk factors for stroke.  Antiplatelet agents (aspirin, Plavix or Prasugrel) are also of proven benefit in patients with carotid artery stenosis.  Revascularization of carotid arteries (carotid endarterectomy and carotid artery stenting) are treatment options that should be considered in addition to medical therapy alone.

Carotid artery endarterectomy

Carotid artery endarterectomy is the surgical procedure in which a vascular surgeon surgically opens the carotid artery and removes the plaque from the artery to reduce the risk of future strokes.  The procedure has been proven successful in randomized controlled clinical trials in symptomatic patients with a carotid artery stenosis of greater than 50% (NASCET Trial) or in asymptomatic patients with stenoses greater than 60% (ACAS Trial).  Studies have shown that qualified, skilled and well trained vascular surgeons with a proven track record in performing carotid artery endarterecomies have good outcomes with decreased risk of future strokes in their patients.

Carotid artery stenting

Carotid artery stenting is an effective alternative to carotid artery endarterectomy as demonstrated in randomized controlled clinical trials (SAPPHIRE and CREST Trials).  In carotid artery stenting, an embolic protection device is placed across the carotid artery stenosis.  The embolic protection device reduces embolization of debris during the carotid artery stent deployment.  The carotid artery stent is placed via the embolization device which serves as a tracking mechanism for the carotid artery stent placement.  Once the stent is deployed, the embolization device is removed leaving the deployed stent to improve carotid flow, stabilize and trap plaque.  It should be emphasized that Panama City, FL cardiologists that deploy carotid artery stents must be well qualified, skilled and demonstrate a proven track record in carotid artery stenting as do vascular surgeons in carotid artery endarterectomy procedures.

Therefore, the treatment of patients with carotid artery stenosis can be one of conservative medical management only or one of the invasive carotid artery revascularization methods of carotid artery endarterectomy or carotid artery stenting.  Both methods have been clinically tested in randomized controlled clinical trials and by successful significant registry and clinical data of patient outcomes.  Hence, evidence-based medicine is used by the clinician to select the best treatment option based on the patient’s presentation and co-morbidities.  Carotid artery endarterectomy performed by vascular surgeons with proven track records is the surgical option.  Whereas carotid artery stenting when performed by cardiologists with proven track records should be considered in patients who have co-morbidities or anatomical findings that render carotid artery stenting a better option.  Conservative medical therapy should be reserved for patients who have an occluded carotid artery which is not believed to be optimal for either invasive procedure.

The Cardiovascular Institute of Northwest Florida in Panama City  is a participant in the CHOICE Trial Registry.  The patients are neurologically assessed by an independently qualified professional before the carotid artery stent is deployed, the day after stent deployment and 30 days after deployment.  Presently over 60 patients enrolled by the Cardiovascular Institute of Northwest Florida have had no TIA’s or strokes.  The FDA approved carotid artery stenting for patients at high risk for carotid artery endarterectomy in 2004, but the CMS which reimburses carotid artery stenting allowed payment only for those patients who were also symptomatic.  Although the FDA recently approved carotid artery stenting for asymptomatic high risk patients, CMS has not approved carotid artery stenting unless the patients are symptomatic.  However, if the patients are asymptomatic, carotid artery stenting is available only by physicians and hospitals who are participants in highly scrutinized study or registry such as the CHOICE Registry.  Fortunately patients in this area are allowed access to this beneficial technology.