A novel approach to protect the brain
Innovations in Cardiovascular Medicine & Surgery - Fall 2018
VIKRAM S. KASHYAP, MD
Chief, Division of Vascular Surgery and Endovascular Therapy, UH Cleveland Medical Center, Co-Director, Vascular Center, UH Harrington Heart & Vascular Institute; Professor, Surgery, Case Western Reserve University School of Medicine
An estimated 20 to 30 percent of ischemic stroke is caused by carotid artery disease. Vascular surgeons of the Harrington Heart & Vascular Institute at University Hospitals Cleveland Medical Center are offering a novel alternative for treating carotid artery stenosis in patients considered high risk for traditional carotid endarterectomy (CEA).
“Carotid atherosclerosis has been treated effectively with CEA for the past fifty years,” says Vikram S. Kashyap, MD, Chief of the Division of Vascular Surgery and Endovascular Therapy at University Hospitals Cleveland Medical Center. “However, in some cases there is a greater risk for complications. Patients coming to us are seeking an alternative to carotid endarterectomy.”
Reasons CEA may be contraindicated include anatomic factors such as prior stenting, scarring, cancer or radiation of the neck. Physiologic factors, including heart failure or pulmonary disease, can also preclude patients from the surgery. In cases where CEA is not an option, stenting through the femoral artery has been a possible treatment but the procedure carries a higher risk for stroke caused by plaque breaking off and traveling to the brain.
UH experts have adopted an innovative approach – TransCarotid Artery Revascularization (TCAR) developed by Silk Road Medical® – that utilizes the ENROUTE® Transcarotid Neuroprotection System to isolate the blockage from forward blood flow while stenting the carotid artery. “The TCAR procedure provides a compelling alternative to stenting through the transfemoral artery because before we perform any intervention, we reverse blood flow to capture plaque outside the body,” Dr. Kashyap says.
THE TCAR PROCEDURE
The minimally invasive TCAR procedure enables the surgeon to directly access the common carotid artery through a small incision above the clavicle. Utilizing high-quality imaging to guide placement, a flexible sheath is inserted at the carotid bifurcation. The sheath is then connected to a patented circuit that provides temporary dynamic reversal of blood flow through a filter to trap any micro emboli that may dislodge during the procedure.
High pressure in the small cerebral arteries and low pressure in the large femoral vein results in a pressure gradient that allows for blood flow to be reversed away from the brain and returned through access placed in the groin. While blood flow is reversed, the surgeon places the ENROUTE® Transcarotid Stent. Balloon angioplasty can also be completed at this time if indicated.
“The procedure is predicated on maintaining cerebral flow through the contralateral carotid artery and vertebral vessels,” Dr. Kashyap says. Once the carotid artery is successfully stabilized, the circuit is turned off and blood flow resumes normally.
The clinically proven procedure takes 60 to 90 minutes and is performed in one of the UH cardiovascular hybrid suites. “We are seeing phenomenal results,” Dr. Kashyap says. “We have treated more than 60 patients using TCAR and have had a zero event rate for stroke during or following the procedure.”
With more than 1,000 patients treated with TCAR nationwide, the event rate for stroke has been about one percent, approximatiVikVng the risk profile for carotid endarterectomy.
ROADSTER 2 STUDY
Dr. Kashyap is the national co-principal investigator for the ROADSTER 2 registry, an FDA-mandated, multi-center post-approval study (PAS) of 600+ patients, designed to further assess the safety and effectiveness of the ENROUTE stent and system in real-world use. The study is focusing on a broader national application of the procedure, with more than 70 percent of patient enrollment stemming from new TCAR providers.
“We have found that the learning curve is very steep, meaning surgeons become accustomed to the procedure after only a small number of cases,” says Dr. Kashyap. “As additional sites start up, we think TCAR is going to alter the landscape for treatment.”
Anticipated to run through January 2019, ROADSTER 2 targets patients with atherosclerotic extracranial internal carotid stenosis (ICA). The primary endpoint is procedural success and absence of stroke, myocardial infarction or death for 30 days following stent placement. Interim analysis of ROADSTER 2 data has been very encouraging.
“We are offering hope to patients who have limited options because of their high risk for other types of intervention,” Dr. Kashyap says. “This technique may change our paradigm for how we treat patients with cerebral vascular disease and offer an alternative not only to transfemoral carotid artery stenting but also carotid endarterectomy.”