Patent Publication Number: US-2011077680-A1

Title: Large mouth snare device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a Continuation-in-Part of and claims priority to U.S. patent application Ser. No. 12/021,204, filed Jan. 28, 2008, entitled “SNARE DEVICE,” the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments relate to methods and devices for the removal of objects from within the vasculature, particularly methods and devices for the removal of large and/or sharp objects. 
     BACKGROUND 
     The removal of objects from tubular vessels within a living body can be difficult. For example, naturally occurring objects that can be difficult to remove include thrombi and clots, and artificial objects that can be difficult to remove include valvular prostheses, closure devices for patent foramen ovale (PFO), atrial septal defect devices, ventricular septal defect devices, stents, and the like. Artificial objects can be especially difficult to remove when those objects expand during placement and/or have sharp edges or protrusions. When removing objects from tubular vessels in living bodies, thin-walled arteries and vessels can be traumatized. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. 
         FIG. 1  illustrates an embodiment of a large mouth snare device being advanced through the inferior vena cava through a large bore flexible sheath, and a target object (illustrated as a displaced CardioSeal™ device) is shown in the pulmonary artery, in accordance with various embodiments; 
         FIG. 2  illustrates a snare device being advanced toward a target object in the pulmonary artery, in accordance with various embodiments; 
         FIG. 3A  illustrates a snare device grasping the target object in the pulmonary artery. in accordance with various embodiments; 
         FIG. 3B  illustrates a close-up view of the snare device and target object shown in  FIG. 3A , in accordance with various embodiments; 
         FIG. 4  illustrates a flexible sheath being advanced up the pulmonary artery toward a snare device, in accordance with various embodiments; 
         FIG. 5  illustrates the deployment of a funnel device when the flexible sheath is withdrawn, in accordance with various embodiments; 
         FIG. 6A  illustrates a snare device and target object being retracted into the mouth of a funnel device and enveloped at least partially therein, in accordance with various embodiments; 
         FIG. 6B  illustrates a close-up view of the snare device and target object being retracted into the mouth of the funnel device shown in  FIG. 6A , in accordance with various embodiments; 
         FIG. 7  illustrates a snare device and target object completely enveloped by a funnel device, in accordance with various embodiments; 
         FIG. 8  illustrates a funnel device being retracted back into a flexible sheath with snare device and target object completely enveloped therein, in accordance with various embodiments; 
         FIG. 9  illustrates a funnel device fully retracted back into a flexible sheath with a snare device and target object completely enveloped therein, in accordance with various embodiments; 
         FIG. 10  illustrates a flexible sheath (which contains a snare device, target object, and funnel device, not shown) being withdrawn into a larger sheath, such as a 24 French sheath, in the inferior vena cava and out of the body, in accordance with various embodiments; and 
         FIG. 11  illustrates the heart, lungs, pulmonary arteries, inferior vena cava, and associated structures, and shows a loose CardioSeal™ device in the pulmonary artery, an aortic percutaneous valve that has been displaced in the mid aorta, and a stent that has been misplaced in the iliac artery, all of which may be safely removed using the devices and methods disclosed herein, in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration embodiments that may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents. 
     Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments; however, the order of description should not be construed to imply that these operations are order dependent. 
     The description may use perspective-based descriptions such as up/down, back/front, and top/bottom. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of disclosed embodiments. 
     The terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other. 
     For the purposes of the description, a phrase in the form “NB” or in the form “A and/or B” means (A), (B), or (A and B). For the purposes of the description, a phrase in the form “at least one of A, B, and C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). For the purposes of the description, a phrase in the form “(A)B” means (B) or (AB) that is, A is an optional element. 
     The description may use the terms “embodiment” or “embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments, are synonymous. 
     Embodiments disclosed herein provide devices and methods for removing objects, such as thrombi, clots, or man-made objects, from the vasculature without damaging vascular or cardiac structures. In various embodiments, the devices may include a conventional vascular snare device, such as those disclosed in U.S. patent application Ser. No. 12/021,204, which is herein incorporated by reference in its entirety. The snare device may be deployed through a large bore flexible sheath that contains an expandable funnel element at its distal end. In use, once the snare device has been used to capture a desired object, the object may be retracted into the expanded funnel element, which may then partially or completely envelop the captured object and protect the surrounding vascular structures from damage. In some embodiments, the funnel element may then be retracted into the large bore flexible sheath, which may expand to envelop the object and secure it within the device, thus enabling the object to be safely withdrawn from the body without causing damage to the vasculature. 
       FIG. 1  depicts an embodiment of the large mouth snare device  10  being advanced through the inferior vena cava through a large bore flexible sheath  12  such as a, 18 French sheath. In some embodiments, flexible sheath  12  may be made from a silastic or rubber-like material that may be very malleable, expandable, and/or flexible. Specific, non-limiting examples of suitable materials include polytetrafluoroethylene (PTFE), nylon, plastic, silicone, neoprene, rubber, and expandable urethane. In various embodiments, flexible sheath  12  may be advanced over a guidewire (not shown) such as a 0.014 inch-0.035 inch wire, and may be contained inside a second, larger sheath (not shown) such as a 24 French sheath. Flexible sheath  12  also may contain funnel device  16 , which may be advanced along guidewire  14  in the collapsed state along with flexible sheath  12 .  FIG. 1  also depicts a target object  18  (which is illustrated as a displaced CardioSeal™ device, but may be any naturally-occurring or man-made object) in the pulmonary artery. 
       FIG. 2  illustrates a snare device  20  being advanced toward target object  18 . Any snare system can be used with the disclosed system, such as the Elite™ manufactured by Radius Inc., the Gooseneck Snare Device manufactured by EV3, those disclosed in U.S. patent application Ser. No. 12/021,204, or any other snare or claw device, although a claw-type snare is depicted. In some embodiments, snare device  20  may be advanced along a guidewire if the guidewire has already been advanced to target object  18 . Alternatively, the guidewire may be withdrawn and snare device  20  may be advanced without a guidewire. 
       FIG. 3A  depicts snare device  20  grasping target object  18  in the pulmonary artery. In some embodiments, target object  18  may have one or more sharp edges or corners, which may cause damage to the vasculature during removal. For example, in addition to naturally occurring objects such as clots, foreign bodies sometimes must be removed from the vasculature. These foreign bodies may include, for example, components of artificial valves, patches used for repairing atrial septal defects (ASDs), or other man-made devices such as embolism-preventing filters, stents, closure devices for patent foramen ovale (PFO), closure devices for ventricular septal defects, and the like. For example, an ASD patch deviceβ may become separated from the cardiac tissue and embolize into the right atrium and/or pulmonary artery. Examples of ASD devices include, for example, the CardioSeal™ device shown in  FIG. 3B , the AGA Amplatzer™, the Gore Helix™ device. Other intravascular devices also can be removed with the snare device  20 . 
       FIG. 4  illustrates flexible sheath  12  being advanced up the pulmonary artery toward snare device  20 .  FIG. 5  illustrates the deployment of funnel device  16  when flexible sheath  12  is withdrawn. Although funnel device  16  is depicted as having a funnel shape, one of skill in the art will appreciate that the device may have other shapes that may be configured to open and envelop target object  18 . For instance, funnel device  16  may comprise one or more overlapping petals, and may have a flower or tulip shape. As used herein, the term “funnel device” refers to any such device having a generally funnel-shaped or flower-shaped configuration, and generally having a closed end and an open end for receiving target object  18 . In various embodiments, funnel device  16  may be made from any flexible material, such as fabric, cloth, or mesh material, for example made from PTFE or nylon, or a fine metal mesh such as Nitinol, or any other flexible and expandable material. In some embodiments, funnel device may be biased in the open position such that withdrawing flexible sheath  12  causes funnel device  16  to open. For example, funnel device  16  may include one or more ribs  22  or spring elements to bias it in the open position. Alternatively, funnel device  16  may not be biased in the open direction, but may be positioned such that the flow of blood through the vasculature tends to cause it to open. 
     In some embodiments, funnel device  16  may be sufficiently porous to allow blood to flow through it even when in an open position. When open, the funnel may have an outside diameter of up to about that of a 50 French catheter (e.g., about 17 mm). In some embodiments, funnel device  16  may have a proximal end and a distal end, and may couple to a hollow wire or catheter at or near the proximal end. In some embodiments, the hollow wire or catheter may pass through funnel device  16  and extend beyond the distal end of funnel device  16 . In other embodiments, the hollow wire or catheter may terminate within funnel device, for instance at the proximal end of funnel device  16 . In some embodiments, the hollow wire or catheter may have a lumen that is sized to accommodate the diameter of the guidewire. 
     As shown in  FIG. 6A , once funnel device  16  is open, snare device  20  and target object  18  may be retracted into the mouth of funnel device  16  and enveloped at least partially therein. In various embodiments, funnel device  16  may be sized to be large enough to partially or completely envelop a large target object  18 , as illustrated in  FIG. 6B .  FIG. 7  illustrates snare device  20  and target object  18  completely enveloped by funnel device  16 , and  FIG. 8  illustrates funnel device  16  being retracted back into flexible sheath  12  with snare device  20  and target object  18  completely enveloped therein. 
       FIG. 9  illustrates funnel device  16  fully retracted back into flexible sheath  12  with snare device  20  and target object  18  completely enveloped therein. Although not shown in  FIG. 9 , in use, flexible sheath  12  may stretch to accommodate target object  18 , such that the outer diameter of flexible sheath  12  may be several times larger in the expanded state than in the non-expanded state, for example to the diameter of a 39 French (−13 mm) or 42 (−14 mm) French sheath. Thus, in various embodiments, funnel device  16  and flexible sheath  12  may fully envelop any sharp edges or corners of target object  18 , and may protect the vasculature and cardiac structures from damage while target object  18  is removed from the body.  FIG. 10  illustrates flexible sheath  12  (which contains snare device  20 , target object  18 , and funnel device  16 , not shown) being withdrawn into a larger sheath  24 , such as a 24 French sheath, in the inferior vena cava and out of the body. The next slide shows the device has been removed. 
       FIG. 11  depicts the heart, lungs, pulmonary arteries, inferior vena cava, and associated structures, and shows a loose CardioSeal™ device in the pulmonary artery, an aortic percutaneous valve that has been displaced in the mid aorta, and a stent that has been misplaced in the iliac artery. All of these are foreign objects that may be safely removed using the devices and methods disclosed herein. 
     In use, large mouth snare device  10  may be inserted into the vasculature in any conventional way, for example via a femoral vein or artery, and may be manipulated through the vasculature until its distal end is adjacent to target object  18 . snare device  20  may then be extended from an inner lumen of the large mouth snare device  10 , and may be manipulated such that it grasps target object  18 . Such manipulations depend on the type of snare device used, and are well known to those of skill in the art. 
     Either before or after snare device  20  is deployed, flexible catheter  12  may be retracted slightly, exposing funnel device  16 . When exposed, funnel device may then open, either because it is configured to be biased in the open direction or by the force of blood flow against the open mouth of funnel device  16 . 
     Once snare device  20  has grasped target object  18 , snare device  20  and target object  18  may be withdrawn partially or completely into open funnel device  16  and may be completely or partially encompassed therein. Funnel device  16 , snare device  20 , and target object  18  may then be pulled into the distal end of flexible sheath  24 , which may expand to envelop all or part of funnel device  16 , snare device  20 , and target object  18 . Once so enveloped, target object  18  may be safely removed from the body by retracting large mouth snare device from the vasculature. 
     Although certain embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope. Those with skill in the art will readily appreciate that embodiments may be implemented in a very wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments be limited only by the claims and the equivalents thereof.