Cerebral embolism is a known complication of cardiac surgery, cardiopulmonary bypass and catheter-based interventional cardiology and electrophysiology procedures. Embolic particles, which may include thrombus, atheroma and lipids, may become dislodged by surgical or catheter manipulations and enter the bloodstream, embolizing in the brain or other vital organs downstream. Cerebral embolism can lead to neuropsychological deficits, stroke and even death. Prevention of cerebral embolism benefits patients and improves the outcome of these procedures.
Various embolic protection devices are known in the art. An embolic protection device for side branch vessels of the aortic arch has for instance been disclosed in US 2004/0215167. This embolic protection device has an expandable tubular structure supporting a filter mesh material. The embolic protection device is compressed to a small diameter for insertion into a patient's aorta, and then expanded within the aorta with the filter mesh material positioned to allow blood to enter side branch vessels connected to the aorta and to prevent embolic material from entering the side branch vessels. The device is deployed and left in place for long-term protection. Alternatively, the device may be compressed and withdrawn from the aorta.
However, the embolic protection devices disclosed in 2004/0215167 have a number of drawbacks. The device may be difficult to extract from the aortic arch as a stent like design is devised for permanent implantation and removing a stent may harm the implantation site. The device also forms along the aorta and may at least partly be pressed against or into the ostia regions of the side vessels. Most often these ostia regions are subject to sedimented plaque on the outside of the tissue in these ostia regions. When a stent like device is pressed against the plaque, the latter loosens from the tissue on which it is situated and is washed along the side branch vessels as debris. However, this debris is an undesired embolic material, which the device should avoid to enter the branch vessels.
In U.S. Pat. No. 6,258,120 implantable cerebral protection device is disclosed for diverting emboli away from the carotid arteries in the aorta. The disclosed devices are aortic diverters that generally comprise a hollow tube with a substantially cylindrical or conical wall, which is impermeable to emboli and which has open ends that allow blood to enter one end, flow through the tube and exit the other end. The proximal end of the hollow tube is circumferentially sized to completely fill the lumen of the aorta. Additionally, snowshoe aortic diverters, which are planar rather than cylindrical, are also disclosed. The methods disclosed in U.S. Pat. No. 6,258,120 include the steps of providing an aortic diverter carried by an intravascular catheter, introducing the intravascular catheter into the vascular system, advancing the intravascular catheter into the aortic arch to the region of the carotid arteries, and deploying the aortic diverter.
However, like the devices disclosed in US 2004/0215167, the devices and methods of U.S. Pat. No. 6,258,120 may damage the aortic vessel wall. Furthermore, a leakage of embolic material into the side branch vessels of the aortic arch may be present, e.g. past the periphery of the tubular structure, or of the snowshoe like embodiments disclosed. Moreover, the devices disclosed may, at least partly, contact the ostia of the side branch vessels, and thus set free embolic debris from the ostia which is carried to the carotid arteries and may lead to cerebral damage. Further, a backflow carrying embolic material may occur from the distal end of the devices of U.S. Pat. No. 6,258,120 into the side branch vessels. The snowshoe like devices have and attached handle or cannula and need to be installed by means of open chest surgery comprising incising the aorta, which has numerous drawbacks compared to intravascular delivery, including aortic trauma. The devices need to be secured to the lumen of the aorta through various mechanisms including sutures, surgical clips, hooks, adhesive material, substantially rigid sleeves, or frictional engagement. Such securing is difficult to accomplish in a reliable manner via transvascular access.
In US 2008/0065145 an embolic protection device and method of use are disclosed. A blood debris deflector umbrella is disclosed, which has a blood flow permeable covering. The umbrella is extending over the ostia of the brachiocephalic artery and the left carotid artery. The deflector is inserted percutaneously and placed by means of a catheter, either via the right arteria subclavia ending in the aortic arch via the brachiocephalic artery, or the femoral artery and into the brachiocephalic artery and the right arteria subclavia. However, the device has in any case a guide wire arranged extending between the aortic arch and the brachiocephalic artery, which is to be protected by the device. This means that, like in the aforementioned disclosures, the device will inevitably be intravascularly manipulated and thus it will likely contact the ostia of the brachiocephalic artery, i.e. the side branch vessel of the aorta leading to the right carotid artery. Thus a risk for iatrogenic caused embolization is present, i.e. the physician likely will set free embolic debris from the ostia of the brachiocephalic artery when using the device. The embolic debris is carried to the right carotid artery and may lead to cerebral damage.
Moreover, the dome shaped device of US 2008/0065145 appears to be difficult, to work in practice due to the anatomical structure and position of the afore described access way via the brachiocephalic artery. The device will have to be very large in order to cover the ostia of the brachiocephalic artery and the left carotid artery. Thus the device will be very voluminous in the aortic arch.
Hence, known cerebral embolic protection devices have shortcomings, including: difficult to position in a vessel, and even more difficult to position in two vessels; they may cause damage to the vessel wall and potentially cause an emboli themselves; they are hindering surgeons when trying to achieve a good result with some intended intervention/operation; visualization of the protective device may impair visualization of other components used during concurrent medical procedures; they may cause impaired flow if they are designed to collect the embolic material.
Thus, there is a need for a new, or improved, or alternative device, or method for preventing embolic material from entering branch vessels, such as the aortic arch side branch vessels, and/or from creating debris from the ostia of the aortic arch side branch vessels that may be carried towards the brain of a patient during a medical procedure.
Hence, an improved embolic protection device or method would be advantageous.