Abstract:
An apparatus for performing a medical procedure and, in particular, an aortic valvuloplasty, in a vessel for transmitting a flow of fluid. The apparatus includes an inflatable perfusion balloon including an internal passage for permitting the fluid flow in the vessel while the perfusion balloon is in an inflated condition, the balloon including a plurality of cells in a single cross section and a covering for at least partially covering the cells. A valve associated with the balloon controls the fluid flow within the passage, the valve being arranged external to the passage. The valve may form a tubular extension of the covering, or may be separate from the covering, and may comprise flaps. A spiral covering may also form the valve.

Description:
INCORPORATION BY REFERENCE 
       [0001]    All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. 
       BACKGROUND 
       [0002]    Expandable devices, such as balloons, are widely used in medical procedures. In the case of a balloon, it is inserted into a body, typically on the end of a catheter, until the balloon reaches the area of interest. Adding pressure to the balloon causes the balloon to inflate. In one variation of use, the balloon creates a space inside the body when inflated. 
         [0003]    Balloons may be used in the valves associated with the heart, including during Balloon Aortic Valvuloplasty (BAV) (as described in Hara et al. “Percutaneous balloon aortic valvuloplasty revisited: time for a renaissance?”  Circulation  2007; 115:e334-8) and Transcatheter Aortic Valve Implantation (TAVI)). For such a procedure, the inflated balloon may be designed to allow for continued blood flow, or perfusion. However, when the balloon is inflated, the heart valve is necessarily temporarily disabled. This can lead to disruptions in the blood flow, including by creating undesirable back flow. 
         [0004]    Thus, it would be desirable to provide a perfusion balloon that can be used to regulate the flow of fluid during a procedure, especially when used in connection with a procedure involving a valve that is disabled as a result of the procedure or otherwise. 
       SUMMARY OF THE DISCLOSURE 
       [0005]    The technical effect of the disclosed embodiments may be considered to include achieving valving external to a perfusion balloon, which creates an enhanced flow of fluid during the opening of the valve, enhanced blocking of the flow during the closing of the valve, and/or creates an easier manner to manufacture the balloon (especially in the case where it includes a non-compliant shell over the balloon). In one embodiment, a single valve may be used to regulate the flow through the entire passage allowing perfusion, such as by simultaneously blocking and unblocking multiple entrances to the passage. 
         [0006]    According to one aspect of the disclosure, an apparatus for performing a medical procedure in a vessel for transmitting a flow of fluid. The apparatus comprises an inflatable perfusion balloon including an internal passage having a plurality of entrances for permitting the fluid flow in the vessel while the perfusion balloon is in an inflated condition. A valve is associated with the balloon for controlling the fluid flow within the passage. The valve is for selectively covering the entrances to the passage to control the flow of fluid therein. The valve thus includes a first condition or position spaced from the entrances for allowing fluid to flow into the internal passage and a second condition or position closer to the entrances than in the first condition or position for restricting the flow of fluid to the passage. 
         [0007]    In one embodiment, the valve comprises a tube. The tube may have a generally circular, continuous cross-section. The balloon may comprise a generally tapered portion, and the tube extends along the generally tapered portion. The balloon may comprise a plurality of cells in a single cross-section, and a covering for covering the cells. The tube may be an extension of the covering. Each cell includes a neck in communication with an inflation lumen of a shaft supporting the balloon, and tube may overlie the necks. The tube may be located at a proximal end portion of the balloon. 
         [0008]    According to a further aspect of the disclosure, an apparatus for performing a medical procedure in a vessel for transmitting a flow of fluid is provided. The apparatus comprises an inflatable perfusion balloon including an internal passage for permitting the fluid flow in the vessel while the perfusion balloon is in an inflated condition. A valve associated with the balloon is provided for controlling the fluid flow within the passage. The valve comprises a plurality of elongated flaps for covering the entrance. 
         [0009]    In one embodiment, the flaps are fixed at a proximal end (that is, at the end corresponding to the shaft supporting the balloon) for selectively covering an entrance to the passage to control the flow of fluid therein. The fixed proximal end is connected to the balloon, and the flaps each include a distal end that is not connected to the balloon. The balloon may comprise a generally tapered portion, and the flaps may extend along the generally tapered portion. The flaps may each include a distal end connected to the balloon by a tether. The flaps may be narrower at the fixed proximal end that at a distal end. A sheath may also be provided for covering any valve disclosed herein, such as for example the extension of the tube, the plurality of flaps or otherwise. 
         [0010]    Still a further aspect of the disclosure pertains to an apparatus for performing a medical procedure in a vessel for transmitting a flow of fluid. The apparatus comprises an inflatable perfusion balloon including an internal passage for permitting the fluid flow in the vessel while the perfusion balloon is in an inflated condition. A valve is associated with the balloon for controlling the fluid flow within the passage, the valve comprising a spiral covering adapted for compressing to restrict fluid flow to or from the passage and for expanding to permit fluid flow to or from the passage. 
         [0011]    In one embodiment, the spiral covering comprises an elongated piece of material wound spirally over the balloon. The spiral covering comprises a material having a frusto-conical with a spiral cut therein. The balloon may comprise a generally tapered portion, and the spiral covering extends along the generally tapered portion. 
         [0012]    The balloon may comprise a plurality of cells in a single cross-section, and a covering for covering the cells, and wherein the spiral covering is an extension of the covering. Each cell may have a neck in communication with an inflation lumen of a shaft supporting the balloon, and wherein the spiral covering overlies the necks. The spiral covering may be located at a proximal end portion of the balloon. 
         [0013]    Yet another aspect of the disclosure pertains to an apparatus for performing a medical procedure in a vessel for transmitting a flow of fluid. The apparatus comprises an inflatable perfusion balloon including an internal passage for permitting the fluid flow in the vessel while the perfusion balloon is in an inflated condition. The balloon includes a plurality of cells in a single cross section and a covering for at least partially covering the cells. A valve associated with the balloon is for controlling the fluid flow within the passage, the valve being arranged external to the passage and separate from the covering, which may be non-compliant. 
         [0014]    In one embodiment, the valve comprises a material having a generally frusto-conical shape and extending along a tapered portion of the balloon, the material including a plurality of openings (such as for example, slits) for allowing fluid flow to or from the passage, which may be covered by flaps. The valve may comprise a spiral covering extending along a tapered portion of the balloon. The valve may comprise a plurality of elongated flaps for selectively covering an entrance to the passage to control the flow of fluid therein, the flaps having a fixed proximal end. As noted above, any embodiment may include a sheath for at least partially covering the valve. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a perspective view of an inflatable device in the expanded condition; 
           [0016]      FIG. 2  is a perspective view of an inflatable device in the expanded condition, and including an outer covering or shell; 
           [0017]      FIG. 3  is a perspective view of an inflatable device including an extended covering or shell forming a valve; 
           [0018]      FIG. 4  is a cross-sectional view along line  4 - 4  of  FIG. 3  with the valve in a first position for permitting flow through a central passage of the device; 
           [0019]      FIG. 5  is a cross-sectional side view of the device of  FIG. 4 , with the valve in a second position for restricting flow through a central passage of the device; 
           [0020]      FIG. 6  is a perspective view of an inflatable device including a further embodiment of a valve; 
           [0021]      FIG. 7  is a cross-sectional view along line  7 - 7  of  FIG. 6  with the valve in a first position for restricting flow through a central passage of the device; 
           [0022]      FIG. 8  is a cross-sectional side view of the device of  FIG. 7 , with the valve in a second position for permitting flow through a central passage of the device; 
           [0023]      FIG. 9  is a perspective view of an inflatable device including a further embodiment of a valve; 
           [0024]      FIG. 10  is a cross-sectional view along line  10 - 10  of  FIG. 9  with the valve in a first position for restricting flow through a central passage of the device; 
           [0025]      FIG. 11  is a cross-sectional side view of the device of  FIG. 9 , with the valve in a second position for permitting flow through a central passage of the device; 
           [0026]      FIG. 12  is a perspective view of an inflatable device including a further embodiment of a valve; 
           [0027]      FIG. 13  is a cross-sectional view along line  13 - 13  of  FIG. 12  with the valve in a first position for permitting flow through a central passage of the device; and 
           [0028]      FIG. 14  is a cross-sectional side view of the device of  FIG. 13 , with the valve in a second position for restricting flow through a central passage of the device. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    The invention disclosed pertains to an inflatable device in the nature of a perfusion balloon. The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings. 
         [0030]      FIG. 1  shows an inflatable device  10  including a perfusion balloon  12  in an inflated condition, ready for use in connection with a procedure (but which balloon would normally be folded for purposes of delivery through the vasculature to a selected treatment area, such as the aortic valve). From viewing the inflated condition, it can be understood that the balloon  12  of the device  10  may have multiple inflatable cells  12   a  (eight shown, but any number may be provided) in at least a single cross-section of the balloon. As indicated in  FIG. 2 , a retainer, such as a tubular, flexible sheath or covering  18  forming a shell or jacket may be provided over the central portion of the cells  12   a  to retain them in a generally annular configuration in the illustrated embodiment, and may also serve to protect the cells when contact is made with a stenosed valve or the like. The covering  18  may be non-compliant to prevent further expansion once the cells  12   a  are fully inflated. 
         [0031]    The cells  12   a  may be individual or discrete, separately inflatable balloons. Each cell  12   a  having a separate inflation lumen via neck  12   b,  as noted, and also a neck  12   c  at the distal end, which form generally tapered portions of the balloon  12 . The cells  12   a  may be sealed at a distal tip (such as at the distal end of each neck  12   c ), or may be parts of a single balloon. The latter may be achieved by a segmented, elongated structure folded in a manner that causes the cells  12   a  to form a passage P extending along a central axis X, along which fluid such as blood may continue to flow, even when the balloon  12  is fully inflated (which may be done through a single inflation lumen, or each balloon could have its own inflation lumen). A full description of this type of balloon may be found in International Patent Application Publication No. WO2012099979A1. However, other forms of perfusion balloons could also be used, such as for example a tubular balloon, one having a peripheral (e.g., helical) channel for purposes of allowing fluid flow to occur during inflation, or any combination of these technologies. 
         [0032]    In any case, the device  10  may also include an inner shaft or tube  14  including a lumen L extending along the central axis X, which may be adapted for receiving a guidewire for guiding the device to a treatment location. The inner tube  14  may form part of a catheter shaft or tube  16 , which includes a lumen N in which the inner tube  14  is positioned. The perfusion balloon  12  may in turn be attached to and supported by the catheter shaft  16 , such as at or adjacent the proximal necks  12   b  forming the entrance to passage P, which may receive inflation fluid through the lumen N. 
         [0033]    According to one aspect of the disclosure, the balloon  12  is adapted for selectively regulating the flow of fluid through the passage P. In one disclosed embodiment, this is achieved using a valve  20  external to the balloon  12  (that is, not located within passage P or the interior space between the necks  12   b,    12   c  and the shaft or tube  14 ) that selectively actuates in a passive manner, such as an extension  18   a  of the covering  18 . The extension  18   a  is arranged for allowing flow through the passage P in a first position or condition when unactuated ( FIGS. 3 and 4 ), for example such that the single extension blocks the multiple entrances to the passage. In a second position or condition, the valve  20  formed by extension  18   a  may cover the entrance to the passage P (that is, the spaces between the necks  12   b  of cells  12   a ) to substantially block it (note extension  18   a ′ in  FIG. 5 ) and thus retard or prevent fluid flow when actuated (which may be achieved passively as the result of the flow of fluid in the corresponding vessel resulting from circulation). The valve may thus repeatedly and regularly restrict and allow fluid flow through the passage P when the balloon  12  is inflated, such as in the space including the aortic valve, and thus mimics the function of the otherwise disabled valve. Consequently, the extension  18  (which may be a single element in this embodiment, despite covering one or more entrances to the passage P) provides a one way valve function during a procedure using the device  10 . 
         [0034]    The extension  18   a  may be formed of a flexible material having a generally tubular shape, and may have a generally circular cross-section. The material forming the extension  18   a  may be continuous, but could also be provided in two or more segments in order to achieve the valving function (e.g., two segments to simulate a bicuspid valve, three to simulate a tricuspid, etc.). The extension  18   a  may also form a unitary structure with the covering  18 , but could also be a separate structure attached to the balloon  12  (either in juxtaposition with the covering, or as a layer above or below it). The length of the extension  18   a  may be selected to provide the appropriate covering for the entrance to the passage P when folded, which of course will depend on the size and geometry of the balloon  12 . 
         [0035]    The material forming the valve  18  may also optionally be provided with properties to facilitate preferential folding when the balloon  12  is collapsed, and then expanded. This may be achieved, for example, by the use of different thickness of material to create a living hinge or like structure that causes the material to fold in a certain manner. The material of the valve body may also be provided with fold lines, pleats, or supports to cause folding and unfolding to occur in a preferential manner to ensure that the valve  18  expands or collapses in the intended way to achieve the desired valving function. 
         [0036]    As noted, the external valve  20  may also be provided as a structure separate from the jacket or covering  18  over the central portion of balloon  12 . As one example, reference is made to  FIGS. 6-8 , which illustrate an embodiment in which the valve  20  comprises a plurality of components, such as flaps  22 , for blocking the entrance to the passage P. The flaps  22  may be partially attached to the balloon  12  (such as to necks  12   b ) or the shaft  16 , such as by fixing at the proximal end of the flaps (corresponding to the proximal end of the balloon  12 , including a connection to shaft  16 ), but unattached at the distal end (corresponding to the distal end of the balloon, such as including the tip). The situation could be reversed if the flaps  22  are positioned at the distal end of the balloon  12 , or the flaps could be similarly arranged at the distal end. 
         [0037]    Consequently, as can be understood by comparing  FIGS. 7 and 8 , the flaps  22  may cover the entrance to the passage P in an unactuated condition, and then actuate ( 22 ′ in  FIG. 8 ) to allow fluid to flow through the passage, thereby creating a one way valve. One or more connectors, such as tether(s)  24 , may also be provided to prevent one or more of the flaps  22  from folding or inverting. The tether  24  may be a thin, flexible structure, such as a wire, fiber, ribbon, or the like, so as to avoid significantly impeding the flow of fluid when the valve  20  is open (which could also be achieved by attaching the distal ends, such as to the necks  12   b  or another portion of the balloon  12 ). 
         [0038]    An optional sheath  26  may also be provided to assist in the capture or retention of the flaps  22  for purposes of withdrawing the balloon  12  when deflated. Such a sheath  26  could also be used in connection with other of the disclosed embodiments, such as for example the extension  18   a  or the embodiments described below, including to withdraw the valve  20  and balloon  12 , and/or to ensure that valving function is controlled or regulated. 
         [0039]    Another approach to an external valve  20  is illustrated with reference to  FIGS. 9-11 . In this arrangement, the valve  20  comprises a spiral covering  28 . This covering  28  may either be an elongated piece of material wound spirally around the balloon  12 , such as along and over the proximal necks  12   b,  of a piece of generally frusto-conical material that is spirally cut. The material forming the covering  28  may be connected at the proximal and distal end portions to the balloon  12  (either directly through bonding, or by way of a connector, such as a tether). The proximal end may alternatively be connected to the shaft  16 . The material may also form an extension of the covering  18 . 
         [0040]    In any case, the gaps or cuts thus provided as a result of the spiral covering  28  allow for fluid flow from the passage P in the proximal direction in the illustrated embodiment (note  28 ′ in  FIG. 11 ), which may also result from movement of the material forming the spiral covering  28  in the axial or longitudinal direction. The resulting openings are then closed off when the fluid flow direction reverses to prevent flow in the opposite direction (including possibly by compression of the material forming the spiral covering in the longitudinal direction). A one way valve thus results. The aforementioned sheath (not shown) may also be used in this arrangement, as could the connectors or tethers. 
         [0041]    Still a further arrangement is illustrated in  FIGS. 12-14 . In this embodiment, a piece of frusto-conical material  30  is applied over the necks  12   b,  separate from the material forming the jacket or covering. This material  30  is provided with strategically positioned openings associated with movable parts of the material, such as flaps  30   a.  These flaps  30   a  may passively open ( FIGS. 12 and 13 ) to allow fluid to flow to or from passage P, and then close ( 30   a ′ in  FIG. 14 ) to restrict the flow. While six flaps  30   a  are shown, it can be appreciated that any number may be provided along the entire circumference of the tapered portion of the balloon  12 , as may be desired to achieve a particular degree of valving function. The flaps  18   a  may also be generally aligned in the longitudinal and circumferential directions, as shown, or may be irregularly spaced in either or both of these directions. 
         [0042]    The flaps  30   a  may be formed by cutting the material  30 , which may be a thin film (as contrasted with the jacket or covering  18 , which is normally made of fibers and in a manner than renders the balloon  12  non-compliant when inflated), in a manner that simply leaves a hinge. Consequently, the flaps  30   a  are free to open and close in response to fluid flow, and thereby substantially obstruct the entrance and thus regulate the flow through passage P as a result. The opening and closing of the flaps  30   a  may be in any direction. The arrangement may also be provided in a manner that simulates fish gills, and thus the openings may simply be provided as slits that are not covered by separate flaps  30   a,  but simply open and close as a result of the flexing of the material. 
         [0043]    Various materials may be used for forming the described structures, including as outlined in International Patent Application Publication No. WO2012099979A1. 
         [0044]    The foregoing discussion is intended to provide an illustration of the inventive concepts, and is not intended to limit the invention to any particular mode or form. In all embodiments, the location or orientation of the valve  20  may be reversed (e.g., distal or proximal position, or alternate facing) for a transapical procedure. Any elements described herein as singular can be pluralized (i.e., anything described as “one” can be more than one), and plural elements can be used individually. Characteristics disclosed of a single variation of an element, the device, the methods, or combinations thereof can be used or apply for other variations, for example, dimensions, burst pressures, shapes, materials, or combinations thereof. Any species element of a genus element can have the characteristics or elements of any other species element of that genus. Terms like “generally” or “substantially” mean that the value may vary depending on the circumstances, such as up to 10% of a given condition. The above-described configurations, elements or complete assemblies and methods and their elements for carrying out the invention, and variations of aspects of the invention can be combined and modified with each other in any combination, along with any obvious modifications.