Evidence for Cerebral Embolic Prevention in Transcatheter Aortic Valve Implantation and Thoracic Endovascular Aortic Repair

Background: Embolic stroke is a formidable complication of transcatheter aortic valve implantation (TAVI) and thoracic endovascular aortic repair (TEVAR). Mechanical strategies to reduce the risk of ischemic embolic lesions include embolic protection devices (EPDs) and carbon dioxide flushing (CDF). This study aims to assess the efficacy for EPD and CDF uses in TAVI and TEVAR. Methods: A literature review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis. All searches were performed via PubMed, OvidSP, MEDLINE, Web of Science Core Collection, and Cochrane Library. Conference abstracts and proceedings were included. Those that were out of scope of interest and review articles were excluded. Results: Eighteen studies fulfilled the inclusion criteria of the 456 articles searched. Regarding EPD use in TAVI, systematic review comparing EPD with no-EPD showed smaller total volume of cerebral lesions and smaller volume per lesion in patients with EPD in all studies. They also performed better in postoperative neurocognitive assessments but could not demonstrate clinical prevention of embolic stroke in all studies. While for EPD use in TEVAR, capture of embolic debris and absence of early postoperative neurocognitive deficit were demonstrated in all cases of 2 prospective pilot studies. Concerning CDF in TEVAR, significant reduction in gaseous emboli released during stent-graft deployment was shown by 1 in vitro study. Successful CDF application in all patients, with only 1 case of postoperative nondisabling stroke, was also demonstrated by 1 cohort study. Conclusions: This systematic review of medical literature has demonstrated the safety and feasibility of EPD use in TAVI. Although improvements in clinical outcomes have yet been demonstrated, there was level I evidence showing reduced embolic lesions in imaging. The use of EPD and CDF in TEVAR was suggested, but evidence remained inadequate to support routine clinical use.