Transcarotid Artery Revascularization (TCAR) is a minimally invasive surgical option for treating carotid artery disease. Approved by the Food and Drug Administration (FDA) in 2015, TCAR is a hybrid procedure combining surgical access with endovascular stenting technology. It is designed to open narrowed carotid arteries while providing unique brain protection against stroke during the intervention. TCAR is often used for patients at higher risk for traditional open surgery.
The Condition TCAR Treats
The primary medical concern addressed by TCAR is Carotid Artery Disease, also known as carotid stenosis. This condition involves the narrowing of the carotid arteries, the two large vessels in the neck that supply oxygenated blood to the brain. The narrowing is caused by atherosclerosis, the buildup of fatty deposits, cholesterol, and cellular waste products called plaque.
As plaque accumulates, the inner diameter of the artery shrinks, restricting blood flow to the brain. If a piece of this fragile plaque breaks off and travels upstream, it can lodge in a smaller blood vessel, blocking flow and resulting in an ischemic stroke. Treatment focuses on stabilizing the plaque and restoring adequate blood flow to prevent this devastating outcome.
The Mechanism of Flow Reversal
The core innovation of the TCAR procedure is its temporary reversal of blood flow, a neuroprotection strategy that sets it apart from other methods. The procedure begins with a small incision, typically made just above the collarbone. Through this direct access point, a specialized sheath is inserted into the common carotid artery.
This sheath connects to an external system that briefly directs blood flow away from the brain. The system uses the body’s natural blood pressure to draw blood out of the carotid artery, reversing its normal direction. This reversed flow diverts any loose particles of plaque or debris generated during the subsequent stenting process away from the cerebral circulation.
The blood is then passed through a specialized filter outside the body to capture micro-emboli or debris. After filtration, the cleaned blood is returned to the body through a separate access point, often a sheath placed in a large vein in the patient’s groin. While the brain is protected by this temporary flow reversal, a self-expanding stent is placed across the narrowed section of the carotid artery to compress the plaque and hold the vessel open. Once the stent is secure, the flow reversal system is turned off, and normal blood flow to the brain is immediately restored.
TCAR Versus Other Carotid Interventions
Before TCAR, the two primary interventions were Carotid Endarterectomy (CEA) and traditional transfemoral Carotid Artery Stenting (TF-CAS). CEA is a traditional open surgery involving a larger incision along the neck to surgically remove the plaque directly from the artery. While highly effective, CEA carries a risk of cranial nerve injury and is considered a major operation.
TF-CAS involves threading catheters from an access point in the groin up through the aortic arch to the carotid artery. This long, indirect route carries a risk of dislodging plaque from the aorta or other vessels during the catheter’s journey. Studies have shown that the perioperative rate of stroke or death for TF-CAS is approximately 3.7%, compared to 2.0% for TCAR and 1.7% for CEA.
TCAR attempts to combine the benefits of both procedures while minimizing their risks. It uses a small, direct surgical access point, reducing the nerve injury risk associated with CEA. Crucially, the flow reversal system offers superior brain protection during stenting compared to the embolic protection devices used in TF-CAS. This combination makes TCAR a favorable alternative, especially for patients considered to be at high risk for traditional open surgery.
Post-Procedure Care and Outcomes
Patients undergoing TCAR generally experience a short hospital stay, often discharged within 24 hours. The recovery period is typically quicker and less painful than that associated with the open incision of a carotid endarterectomy. Patients are advised to avoid heavy lifting and strenuous activity for about one to two weeks, but they can often return to non-strenuous daily activities sooner.
The long-term success of the procedure is measured by its primary goal: stroke prevention. To maintain the open artery and reduce the risk of future plaque buildup, patients are routinely prescribed anti-clotting medications, such as aspirin, and statins. These medications, combined with lifestyle adjustments like diet modification and smoking cessation, are essential for optimizing the long-term outcome and ensuring the continued patency of the stented artery. Regular follow-up with ultrasound imaging is performed to monitor blood flow and detect any signs of restenosis (re-narrowing) within the artery.