Methods of protecting a patient from embolization during surgery

Abstract

An apparatus suitable for filtering emboli in an open surgical procedure. The apparatus comprises an elongated member having a distal region and a support hoop attached to the distal region. A blood permeable sac is affixed to the support hoop so that the support hoop forms a distally-facing mouth of the blood permeable sac. A guidewire is slideably attached to the elongated member. A delivery sheath is provided having a cavity for accepting the elongated member, support hoop and blood permeable sac, and a lumen extending through the cavity to permit the guidewire to pass therethrough. Methods of use are also described.

What is claimed is:  
     
         1 . An apparatus suitable for filtering emboli in an open surgical procedure, comprising: 
 an elongated member having a distal region;    a support hoop attached to the distal region; and    a blood permeable sac affixed to the support hoop so that the support hoop forms a distally-facing mouth of the blood permeable sac;    a guidewire slideably attached to the elongated member; and    a delivery sheath having a cavity for accepting the elongated member, support hoop and blood permeable sac, and a lumen extending through the cavity to permit the guidewire to pass therethrough.    
     
     
         2 . The apparatus of  claim 1 , wherein the blood permeable sac comprises a biocompatible material.  
     
     
         3 . The apparatus of  claim 2 , wherein the biocompatible material comprises a material chosen from a list consisting of polyethylene, polypropylene, polyester, polyurethane and nylon.  
     
     
         4 . The apparatus of  claim 3 , wherein the blood permeable sac comprises a plurality of pores, each one of the plurality of pores having a diameter in a range of 20 to 400 microns.  
     
     
         5 . The apparatus of  claim 1 , wherein the support hoop comprises a super-elastic material.  
     
     
         6 . The apparatus of  claim 1 , wherein the support hoop comprises a wire.  
     
     
         7 . The apparatus of  claim 1 , wherein the elongated member abuts against an interior surface of the cavity so that distal translation of the elongated member is transmitted to the delivery sheath.  
     
     
         8 . The apparatus of  claim 1 , wherein the apparatus has a deployed state, wherein the support hoop engages an interior wall of a patient's vessel, and a delivery state, wherein the apparatus has a contracted configuration to permit insertion of the elongated member, support hoop, and blood permeable sac within the delivery sheath.  
     
     
         9 . The apparatus of  claim 8 , wherein the support hoop folds when the apparatus is contracted to the delivery state.  
     
     
         10 . The apparatus of  claim 8 , wherein the mouth of the blood permeable sac is closed when the apparatus is in the contracted configuration, thereby preventing emboli from escaping from the blood permeable sac.  
     
     
         11 . The apparatus of  claim 10  wherein opposite sides of the support hoop close towards one another when the apparatus is contracted to its contracted configuration.  
     
     
         12 . The apparatus of  claim 1 , wherein the delivery sheath further comprises a radiopaque band.  
     
     
         13 . The apparatus of  claim 1 , wherein the support hoop further comprises a radiopaque band.  
     
     
         14 . A method of trapping emboli or thrombus during an open surgical procedure, the method comprising: 
 providing apparatus comprising an elongated member, a support hoop coupled to the elongated member, a blood permeable sac affixed to the support hoop so that the support hoop forms a distally-facing mouth of the blood permeable sac, a guidewire slideably attached to the elongated member and having a distal region, and a delivery sheath having a cavity for accepting the elongated member, the support hoop, and the blood permeable sac;    advancing the guidewire to a desired location within a patient's vessel;    positioning the elongated member, support hoop, and blood permeable sac in a contracted delivery state within the delivery sheath;    advancing the elongated member and delivery sheath over the guidewire; and    withdrawing the elongated member with the guidewire held stationary to release the support hoop from the cavity so that the apparatus expands to a deployed state wherein the support hoop seals against the vessel wall.    
     
     
         15 . The method of  claim 14 , further comprising: 
 performing the medical procedure, the apparatus catching emboli released when the medical procedure is performed;    advancing the elongated member over the guidewire to return the apparatus to a collapsed configuration within the cavity of the delivery sheath; and    removing the apparatus from the patient's vessel.    
     
     
         16 . The method of  claim 14 , wherein advancing the elongated member and delivery sheath further comprises advancing the elongated member and delivery sheath to a location within the patient's ascending aorta proximal of the aortic valve, so that the apparatus is upstream of the brachiocephalic trunk in the deployed state.  
     
     
         17 . The method of  claim 14 , wherein advancing the elongated member and delivery sheath further comprises advancing the elongated member and delivery sheath against a direction of blood flow through the patient's vessel.  
     
     
         18 . The method of  claim 15 , wherein returning the apparatus to a collapsed configuration within the delivery sheath channel comprises folding the support hoop to close the mouth of the blood permeable sac.  
     
     
         19 . An apparatus suitable for filtering emboli in an open surgical procedure, comprising: 
 an elongated member having a distal region;    a support hoop attached to the distal region;    a blood permeable sac affixed to the support hoop so that the support hoop forms a distally-facing mouth of the blood permeable sac;    a guidewire slideably attached to the elongated member; and    a delivery sheath having a proximally-facing cavity for accepting the elongated member, the support hoop and the blood permeable sac.    
     
     
         20 . The apparatus of  claim 19  further comprising a lumen extending through the cavity to permit the guidewire to pass therethrough.  
     
     
         21 . A method for open surgery on a patient, comprising the steps of: 
 introducing a flexible elongate member into a peripheral artery, the flexible elongate member having a filter on a distal region thereof, the filter comprising a support hoop and a mesh carried by the support hoop, the support hoop having a circumference, the support hoop being coupled to the flexible elongate member at a single point on the circumference of the support hoop;    advancing the filter to a site within the aorta upstream of a branch vessel from the aorta;    deploying the filter at the site;    manipulating the aorta by direct access upstream of the site; and    removing the filter from the aorta.    
     
     
         22 . The method of  claim 21 , wherein the site is in the ascending aorta.  
     
     
         23 . The method of  claim 21 , wherein the peripheral artery is a femoral artery.  
     
     
         24 . The method of  claim 21 , wherein the step of manipulating the aorta by direct access further comprises the steps of blocking the aorta upstream of the site and placing the patient on cardiopulmonary bypass.  
     
     
         25 . The method of  claim 21 , wherein the branch vessel is the brachiocephalic trunk.  
     
     
         26 . The method of  claim 21 , wherein the flexible elongate member, support hoop, and filter are carried within an elongate tubular member, and wherein the step of deploying the filter at the site comprises sliding the support hoop and filter outside the elongate tubular member.