Journal of Invasive Cardiology

There are 3 previous cases that describe a similar approach, 2 of which were outside the setting of emergency PCI,⁷ and 1 in the setting of primary PCI.8 In all of these cases, a FilterWire^™ (Boston Scientific, Natick, Massachusetts) was used, and the culprit artery was the right coronary artery. In the first 2 cases, the filter was placed inside the coronary artery before stent implantation, with the aim of capturing the embolized thrombus, but since the thrombus remained attached to the vessel wall distal to the stent, the filter was used in the open configuration to ensnare the thrombus. In the other case,⁸ the filter was advanced distal to the occlusion, and was then deployed and removed in the open configuration, with entrapment of the clot.

Our case owns some relevant differences compared to the previously reported cases: (1) the Spider filter was chosen due to its low-profile delivery system,⁹ which, unlike the Filter- Wire, allowed us to use a regular wire to pass alongside the thrombus and to position the filter beyond it, minimizing the risk of dislodgment; (2) the conformation of the Spider filter,although potentially more traumatic for the arterial wall than the FilterWire, facilitated the entrapment of the thrombus within the nitinol mesh of the basket; (3) the presence of thrombus in the LAD carried the risk of embolization into the circumflex artery while retrieving the filter. Thus, we removed the filter, only partially closed by the retrieval system, into theguiding catheter that had to be selectively and deeply engaged in the proximal LAD.

We cannot underestimate the potential risks of the procedure described in this case. Indeed, the retrieval maneuver, especially in the case of calcified lesions or tortuosity, might have caused dissection of the left main artery or entrapment of the filter itself inside the coronary artery. Placing a “buddy wire” in the LAD before retrieving the filter would have rendered this a safer procedure.

In conclusion, a “Fogarty-like” use of filter distal protection devices can safely remove large thrombi from occluded coronary arteries, although it must be considered a last-resort rescue technique.