Methods and devices for occluding the ascending aorta and maintaining circulation of oxygenated blood in the patient when the patient's heart is arrested

Abstract

A device and method for occluding a patient's ascending aorta, maintaining circulation of oxygenated blood in the patient and delivering cardioplegic fluid to arrest the patient's heart. An aortic occlusion device has an occluding member in the form of a non-inflatable structure which is moved mechanically between collapsed and expanded orientations. The device is introduced into the ascending aorta in its collapsed orientation and is moved to its expanded orientation to occlude the aorta. The aortic occlusion includes a lumen through which blood is delivered to the patient. The lumen may be provided in the aortic occlusion device or in a separate cannula coupled to the device.

What is claimed is:  
     
         1 . A device for occluding a patient's aorta, the device comprising: 
 a cannula;    an occluding member provided on the cannula and movable between a collapsed orientation and an expanded orientation, the occluding member being sized and configured to occlude a patient's aorta when in said expanded orientation;    wherein the occluding member comprises a non-inflatable structure which moves mechanically from one of said collapsed and expanded orientations to the other of said orientations, the non-inflatable structure having an exterior that is at least substantially impervious to fluid to prevent fluid flow through a patient's aorta when the occluding member is positioned in the aorta in said expanded orientation;    wherein the non-inflatable structure includes a plurality of individual support elements which move relative to each other as the occluding member moves between said collapsed and expanded orientations; and    an actuator for moving the occluding member from one of said collapsed and expanded orientations to the other of said orientations.    
     
     
         2 . The device of  claim 1 , wherein the cannula has a lumen, and the actuator comprises a shaft which is movable within the lumen of the cannula, and each of the individual support elements has a first portion secured to the cannula and a second portion secured to the shaft, whereby relative movement of the cannula and the shaft moves the occluding member between said collapsed and expanded orientations.  
     
     
         3 . The device of  claim 2 , wherein the shaft is axially movable within the lumen of the cannula.  
     
     
         4 . The device of  claim 2 , further comprising a handle including first and second relatively movable portions coupled, respectively, to the cannula and the shaft.  
     
     
         5 . The device of  claim 2 , wherein an annular space is defined between the cannula and the shaft and blood may flow through the annular space into the patient's aorta.  
     
     
         6 . The device of  claim 2 , wherein the shaft has a lumen that communicates a portion of the device located proximal to the occluding member with a portion of the device located distal to the occluding member, and blood may flow through the lumen of the shaft into the patient's aorta.  
     
     
         7 . The device of  claim 1 , wherein the individual support elements are interwoven with each other to form an expandable braided structure.  
     
     
         8 . The device of  claim 7 , wherein each of the individual support elements comprises a plurality of discreet filaments that are disposed generally parallel to each other.  
     
     
         9 . The device of  claim 7 , wherein the individual support elements are coated with a fluid-impervious substance.  
     
     
         10 . The device of  claim 9 , wherein the individual support elements are braided such that the exterior of the occluding member is substantially imperforate when the occluding member is in said collapsed orientation, and such that the exterior of the occluding member defines open areas when the occluding member is in said expanded orientation, the fluid impervious substance preventing fluid flow through the open areas when the occluding member is in said expanded orientation.  
     
     
         11 . The device of  claim 1 , wherein the individual support elements have an integral coating of a fluid-impervious material.  
     
     
         12 . The device of  claim 1 , wherein the fluid-impervious material is silicone.  
     
     
         13 . The device of  claim 1 , wherein the occluding member is generally tubular and includes proximal and distal ends separated by a central portion, the cross-sectional dimensions of the proximal end, distal end and central portion being substantially equal when the occluding member is in said collapsed orientation, and the cross-sectional dimension of the central portion being greater than the cross-sectional dimensions of the proximal and distal ends when the occluding member is in said expanded orientation.  
     
     
         14 . The device of  claim 1 , wherein the occluding member is generally cylindrically-shaped when in said collapsed orientation, and generally bell-shaped when in said expanded orientation.  
     
     
         15 . The device of  claim 14 , wherein the cannula has a lumen passing therethrough, and substantially the entire occluding member is disposed inside the lumen of the cannula when the occluding member is in said collapsed orientation, and substantially the entire occluding member is disposed outside of the lumen of the cannula when the occluding member is in said expanded orientation.  
     
     
         16 . The device of  claim 1 , wherein the individual support elements overlap each other and are movable relative to each other in a circumferential direction with respect to a longitudinal axis of the cannula.  
     
     
         17 . The device of  claim 1 , wherein the individual support elements are flexible struts which are straight when the occluding member is in said collapsed orientation and bowed when the occluding member is in said expanded orientation.  
     
     
         18 . The device of  claim 1 , wherein the individual support elements are helical coils which are closer together when the occluding member is in said collapsed orientation than in said expanded orientation.  
     
     
         19 . The device of  claim 1 , wherein the individual support elements are flexible cross-members secured to each other so as to define adjacent openings, wherein the cross-members flex as the occluding member moves between said collapsed and expanded orientations.  
     
     
         20 . The device of  claim 1 , wherein the individual support elements are covered by a sheath of a fluid-impervious material.  
     
     
         21 . The device of  claim 20 , wherein the fluid-impervious material is silicone.  
     
     
         22 . A device for occluding a patient's aorta, the device comprising: 
 a cannula having a proximal end, a distal end, and a lumen extending through at least a portion of the shaft;    an occluding member movable between a collapsed orientation and an expanded orientation, the occluding member being sized and configured to occlude a patient's aorta when positioned therein in said expanded orientation;    wherein the occluding member comprises a non-inflatable structure which is moved between said collapsed and expanded orientations by mechanical actuation, the non-inflatable structure having an interior in communication with the lumen of the first shaft and an exterior which is substantially impervious to fluid, the exterior of the non-inflatable structure substantially preventing fluid flow through the aorta when the occluding member is positioned in the aorta in said expanded orientation; and    an actuator for moving the occluding member from one of said collapsed and expanded orientations to the other of said orientations.    
     
     
         23 . The device of  claim 22 , wherein the occluding member is secured to the distal end of the cannula such that the interior of the occluding member forms a continuation of the lumen of the cannula.  
     
     
         24 . The device of  claim 22 , wherein the occluding member has a length including proximal and distal ends separated by a central portion, the cross-sectional dimension of the proximal end, distal end and central portion being substantially equal when the occluding member is in said collapsed orientation, and the cross-sectional dimension of the central portion being greater than the cross-sectional dimensions of the proximal and distal ends when the occluding member is in said expanded orientation.  
     
     
         25 . The device of  claim 22 , wherein the occluding member includes a plurality of individual support elements which move relative to each other as the occluding member moves between said collapsed and expanded orientations.  
     
     
         26 . The device of  claim 25 , wherein the individual support elements are interwoven with each other to form an expandable braided structure.  
     
     
         27 . The device of  claim 26 , wherein each of the individual support elements comprises a plurality of discreet filaments that are disposed generally parallel to each other.  
     
     
         28 . The device of  claim 26 , wherein the individual support elements have an integral coating of a fluid-impervious substance.  
     
     
         29 . The device of  claim 22 , wherein the occluding member is generally tubular and includes proximal and distal ends separated by a central portion, the cross-sectional dimensions of the proximal end, distal end and central portion being substantially equal when the occluding member is in said collapsed orientation, and the cross-sectional dimension of the central portion being greater than the cross-sectional dimensions of the proximal and distal ends when the occluding member is in said expanded orientation.  
     
     
         30 . The device of  claim 22 , wherein the occluding member is generally cylindrically-shaped when in said collapsed orientation, and generally bell-shaped when in said expanded orientation.  
     
     
         31 . A method of occluding a patient's aorta and delivering oxygenated blood to the patient's circulatory system, the method comprising steps of: 
 providing a cannula having an occluding member mounted thereon, wherein the occluding member comprises a non-inflatable structure which is movable between a collapsed orientation and an expanded orientation and has an exterior which is substantially impervious to fluid;    positioning the occluding member in a patient's aorta while the occluding member is in said collapsed orientation;    moving the occluding member to said expanded orientation, without inflating the occluding member, to occlude the patient's aorta;    delivering oxygenated blood to the patient's aorta; and    delivering cardioplegic fluid to the patient to arrest the patient's heart.    
     
     
         32 . The method of  claim 31 , wherein the cannula has a lumen passing therethrough and the oxygenated blood is delivered to the patient through the lumen.  
     
     
         33 . The method of  claim 31 , wherein an actuator shaft is positioned in the lumen of the cannula and is coupled to the occluding member for moving the occluding member between said collapsed and expanded orientations, and the actuator shaft has a lumen through which the oxygenated blood is delivered.