A blood filter device (250f) having occlusion-resistant characteristics. The occlusion-resistant characteristics decrease the likelihood of the filter being blocked by thrombi. The filter device includes at least one anchor portion (42) for anchoring the filter device within one or more arteries, and a filter (110) portion for filtering thrombi from the blood entering the artery. In some embodiments, an anchor portion is capped with a filter cap. In various embodiments, the filter cap is protrudes into the aorta to promote occlusion resistance. In one embodiment, the device can be modified in situ to re-establish normal blood flow through the artery in the unlikely case of thrombotic or other blockage of the filter. In some embodiments, a bypass opening or open channel defining an access port is provided to accommodate passage of surgical instruments into the artery and to enable blood flow to bypass the filter should the filter become heavily occluded.
