Transcervical Carotid Artery Revascularization (TCAR) By Boulos Toursarkissian, MD
Approximately every 40 seconds, someone in the United States has a stroke. Carotid artery atherosclerotic disease is a major cause of stroke and disability, causing up to a third of cerebrovascular accidents. Studies have irrevocably shown that, in addition to medical management, the direct treatment by an expert of a significant cervical carotid artery stenosis reduces a patient’s future risk of stroke. This is most beneficial for symptomatic stenoses greater than 50%, but is also of benefit for asymptomatic stenoses greater than 60 to 70%.
Physicians can detect if a patient may be at risk for carotid artery disease by determining if they have risk factors, which include diabetes, history of smoking, obesity, hypertension, family history, associated coronary or peripheral arterial disease and hyperlipidemia, among others. If carotid disease is suspected, the patient should be referred to a board-certified vascular surgeon who can offer the entire spectrum of endovascular and open surgical options. My team at Peripheral Vascular Associates, for example, includes several physicians who are fully versed in the various and latest diagnostic and therapeutic modalities for carotid disease.
Carotid endarterectomy (CEA), a surgical procedure whereby the blockage is physically removed, has been for years the gold standard treatment for significant carotid stenosis with a low perioperative risk in experienced hands. Nearly 20 years ago, transfemoral carotid stenting came to the forefront of treatment options, offering a less invasive alternative. Over the subsequent two decades, numerous studies have shown that carotid artery stenting (CAS) can afford a significant long term stroke reduction benefit, similar to CEA. However, transfemoral carotid stenting comes at the cost of a significant perioperative stroke risk, much higher than the risk associated with CEA. This perioperative CAS associated risk is particularly elevated in those who would benefit the most from a less invasive approach, namely the elderly patients. The risk is such that transfemoral CAS never gained much traction after the initial hype, despite the advent of embolic protection filters destined to catch embolic debris during the stenting procedure.
The reasons for the procedural risks associated with transfemoral CAS lay in the need to cross an often-calcified atherosclerotic aortic arch from a femoral or brachial approach, and the need to traverse the cervical carotid lesion in order to allow the deployment of an embolic protection filter, prior to angioplasty and stenting. To reduce these risks, a new procedure was developed several years ago, referred to as TCAR: transcervical carotid artery revascularization.
TCAR uses an innovative direct cervical approach to the carotid artery at the base of the neck, accessing the common carotid artery via a small cervical cutdown. Therefore, there is no need to traverse any calcified atheromatous aortic arch. A sheath is inserted at the base of the patient’s neck in the artery, through which the stent will be delivered. Furthermore, instead of a filter that requires crossing the carotid lesion for embolic protection, TCAR relies on flow reversal in the internal carotid artery before any wire traverses the lesion. For that purpose, a separate sheath is inserted percutaneously in the patient’s femoral vein. The higher-pressure cervical carotid arterial sheath then is connected to the low pressure femoral venous sheath, thereby establishing flow reversal in the carotid system. Any debris released during the angioplasty/stenting procedure are thus flushed in the venous system, instead of heading upstream in the intracranial arterial bed. The TCAR procedure reverses the direction of blood flow in the carotid, significantly reducing the patient’s risk of stroke during the procedure.
Since its inception, TCAR has been shown to have a perioperative stroke risk remarkably close to that of CEA, while affording a similar long-term stroke risk protection. Advantages of TCAR include a shorter procedure time and a smaller, less painful, and cosmetically more acceptable incision at the base of the neck, which lessens recovery time. It is particularly useful for high-risk patients, such as those with radiated necks, recurrent stenoses after prior CEA, patients with prior neck surgeries, and those with lesions extending high up in the neck, where the risks of cranial nerve injuries with CEA is elevated. Of course, TCAR cannot be applied to all cases. Calcified lesions in particular should be avoided, since these do not usually respond well to angioplasty and stenting. Thrombus laden lesions should also be avoided. Finally, not every patient is a candidate for this type of procedure. Patients must meet certain criteria, and candidacy should be determined by a vascular surgery expert.
In summary, the advent of TCAR has added an additional tool in our armamentarium for dealing with carotid artery occlusive disease, while offering patients a safer way of using the carotid stenting alternative. Innovations like this allow us to better serve our patients and our South Texas community, which sees an increasing need for such care. In fact, San Antonio recently celebrated a milestone in its medical community when Peripheral Vascular Associates and Methodist Hospital | Specialty and Transplant successfully completed the 100th Transcarotid Artery Revascularization procedure (TCAR).
Carotid artery disease affects many in our community. Learn more about this condition with dozens of educational articles and videos provided by the board-certified, highly specialized surgeons who make up our team at Peripheral Vascular Associates (PVA). We offer these resources on our website at PVAsatx.com as a way of raising awareness within our community.
Boulos Toursarkissian, MD is a vascular surgeon and endovascular specialist at Peripheral Vascular Associates (PVA). He is a member of the Bexar County Medical Society (BCMS) and adjunct Professor of Surgery at the UT Health Sciences Center.