Thoracic Endovascular Aortic Repair (TEVAR)
Currently, thoracic endovascular aortic repair (TEVAR) is a procedure that is becoming more popular as a minimally-invasive alternative to surgery among older patients in certain countries. In TEVAR, bulky devices are inserted and placed near the atherosclerotic aortic arch that can liberate debris towards the brain circulation. Because of this, TEVAR patients are at a particularly high risk of brain injury, which may result in cognitive deficit after treatment, such as loss of memory or a reduction in executive function.
Data is emerging that there is a significant cerebral embolization rate and stroke rate associated with TEVAR. One UK study showed a silent cerebral infarction rate with TEVAR of 68%,1 while a neuroimaging study from Germany reported a silent cerebral infarction rate of 63% in patients who underwent TEVAR.2 The same UK study found an overt stroke rate of 13% with TEVAR,1 while another study showed the risk of clinically apparent, periprocedural stroke after TEVAR ranging from 1.9-5.8%.2
The result of this cerebral damage is worrisome. One study of TEVAR patients showed that 88% of patients experienced neurocognitive decline post-procedure.1
Clinically evident strokes and silent cerebral infarctions can be caused by embolic debris, released during certain procedures, that travel through the great vessels to the brain. The first study to examine embolic debris released during TEVAR showed that debris was captured by the Sentinel Cerebral Protection System (CPS) in 100% of procedures. The most prevalent types of debris were pieces of arterial wall, along with acute thrombus and foreign material consistent with hydrogel coatings common in several devices used during the TEVAR procedure.
Despite all of this evidence, embolic protection has not been routinely used in TEVAR to date. However, the clinical community is beginning to take action.
Spurred by the landmark CLEAN-TAVI and MISTRAL-C trials, a feasibility study of the Sentinel CPS used during TEVAR incorporated pre- and post-procedural MRI and neurocognitive testing of patients. Results showed that when the Sentinel CPS was used, half the patients were free of lesions, the remaining half had very small-volume lesions, and 0% of patients exhibited any cognitive deficit. The learning curve for the physicians using the Sentinel CPS was also shown to be rapid, with deployment and retrieval of the device taking 16 minutes in the first case, and only two minutes by the fourth case.
Investigators concluded that the use of the Sentinel CPS in TEVAR is feasible and appears to not only reduce silent cerebral infarcts, but to also exhibit a trend towards protecting patients from neurocognitive decline. Based on this early data, they recommended that the device be tested in a randomized clinical trial.
- Gagandeep Grover, Rudarakanchana N, Perera A, Gibbs R; Mo Hamady, Imperial College London, Thoracic Aortic Stent Grafting
- R. Alexander Jánosi, FESC West-German Heart and Vascular Center Essen University of Duisburg-Essen, Germany, Cerebral Protection against Embolization during Thoracic EndoVascular Aortic Repair
- Grover G, Rudarakanchana N, Perera A, Gibbs R, Hamady M. Cerebral Embolic Protection in Thoracic Aortic Stent Grafting, as presented at ISET 2016.
- Kalhert et al, Ann Thorac Surg 2014
The Sentinel CPS has received the CE Mark and is commercially available in Europe. It is limited to investigational use in the United States.