Patent Publication Number: US-9889276-B2

Title: Systems for anchoring a medical device in a body lumen

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/525,875, filed Jun. 18, 2012, now U.S. Pat. No. 8,998,932, which is a continuation of U.S. patent application Ser. No. 12/955,869, filed Nov. 29, 2010, now U.S. Pat. No. 8,202,281, which is a continuation of Ser. No. 11/552,593, filed Oct. 25, 2006, now U.S. Pat. No. 7,842,049, which is a divisional application of U.S. patent application Ser. No. 10/335,147, filed Dec. 31, 2002, now U.S. Pat. No. 7,160,309, the entire contents of which are incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. The Field of the Invention 
     The present invention relates in general to systems for anchoring medical devices in body lumens, or body cavities. In particular, the present invention relates to systems for anchoring catheters in body lumens, which may include blood vessels. 
     2. The Relevant Technology 
     Various medical procedures require the anchoring of a medical device within a body lumen. All of these systems need to be designed so that the device can be removed at the end of the procedure without causing unacceptable amounts tissue damage. For example, in the case of a catheter anchored in a blood vessel, the catheter must be easily inserted through an opening in the side of the vessel yet also be easily anchored when positioned at its desired location in the vessel. 
     A variety of systems have been designed to anchor a catheter passing into a body lumen through an opening in the side of the body lumen. Most commonly, an inflatable balloon is mounted on the catheter. After the catheter has been positioned at a desired location, the balloon is inflated. The balloon thereby pushes against the walls of the body lumen adjacent to the side opening when the catheter is pulled back, thus holding the catheter in position. Unfortunately, a problem with using such an inflatable balloon is that it typically blocks fluid flow through the lumen, which may not be desirable. Also, in addition to inhibiting fluid circulation, the balloon may interfere with drug delivery systems in the catheter. 
     What is instead desired is a simple system for securing a medical device such as a catheter in a body lumen. Such a system would preferably not interfere with fluid flow through the body lumen (such as blocking fluid flow with an inflatable balloon). In addition, such an anchoring system would preferably be easily removable at the end of the medical procedure. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a versatile system for securing a medical device (such as a catheter) at preferred locations within a body lumen (such as a blood vessel) without blocking or substantially inhibiting fluid flow through the lumen. 
     In preferred embodiments, the present invention includes a sheath having a plurality of side openings; a rotatable element disposed within the sheath; and a plurality of curved projections extending from the rotatable element, wherein rotation of the rotatable element with respect to the sheath pushes distal ends of each of the curved projections outwardly through one of the plurality of openings. In preferred methods of use, the plurality of curved projections are extended outwardly from the rotatable element and are then used to brace against the tissue surrounding a side hole opening into the vessel. Thus, when the device is deployed within the body lumen, and then pulled back (ie: proximally), the curved projections contact the tissue surrounding the side opening into the vessel, thereby preventing the device from being removed. The deployed projections may also provide needle receiving locations in the case of a suturing device, such as a device for suturing an arteriotomy. 
     The present invention also includes an embodiment including a sheath having only one side opening with one curved projection extending from the rotatable element. Similar to the above design, rotation of the rotatable element with respect to the sheath pushes the distal end of the curved projection outwardly through the side opening. In this embodiment, the curved projection may be a wire having one end attached to the rotatable element. 
     In optional preferred embodiments, the curved projection(s) may be biased to spring radially outwardly as they pass through the side opening(s) in the sheath. Alternatively, or in addition, the curved projection(s) may be formed from a shape memory material which assists them in springing radially outwards as they pass through the side opening(s) in the sheath. 
     In various embodiments, the curved projection(s) may either be attached to the rotatable element, or they may be integrally formed into the rotatable element. 
     In various preferred embodiments, the curved projections are opposite ends of a deformable element such as a wire or ribbon. Most preferably, such deformable element passes through (or is fitted around) the central rotatable element. 
     The present invention also provides a method of anchoring a device in a body lumen or cavity, including inserting the device into the body lumen or cavity, and rotating the rotatable element with respect to the sheath, thereby causing the distal ends of each of the curved projections to move outwardly through one of the one or more openings and into the body lumen or cavity. In preferred embodiments of the present method, the body lumen may be any blood vessel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a perspective view of a first embodiment of the invention prior to its deployment. 
         FIG. 1B  is a perspective view of the first embodiment of the invention after it has been deployed. 
         FIG. 2A  is a top plan view corresponding to  FIG. 1A , showing the device passing through a side opening in a vessel lumen, with the distal end of the device positioned within the vessel lumen. 
         FIG. 2B  is a top plan view corresponding to  FIG. 1B , showing the device passing through a side opening in a vessel lumen, with the distal end of the device anchored in the vessel lumen. 
         FIG. 3A  is a side view corresponding to  FIG. 2A . 
         FIG. 3B  is a side view corresponding to  FIG. 2B . 
         FIG. 4  is a perspective view of a second embodiment of the invention. 
         FIG. 5A  is a perspective view of a third embodiment of the invention prior to its deployment. 
         FIG. 5B  is a perspective view of the third embodiment of the invention after it has been deployed. 
         FIG. 6A  is a perspective view of a fourth embodiment of the invention having only one side opening in the sheath. 
         FIG. 6B  is a sectional elevation view corresponding to  FIG. 6A . 
         FIG. 7A  is a perspective view of a fifth embodiment of the invention, in which the invention comprises a suturing device, after its arms have been deployed, but prior to suturing a tissue hole. 
         FIG. 7B  is a perspective view corresponding to  FIG. 7A , but after the tissue hole has been sutured. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1A to 3B  illustrate a first embodiment of the invention which deploys two curved projections that can be used as an anchor against tissue surrounding an opening into a vessel lumen. In this particular example, the two curved projections are opposite ends of a single ribbon shaped element which passes through a central rotatable element of the device. The present invention is not so limited. Rather, other embodiments are also contemplated. 
     For example,  FIGS. 4A and 4B  illustrate a second embodiment of the invention which deploys four curved projections. This embodiment is similar to the first embodiment, but instead uses two ribbon shaped elements which are spaced longitudinally apart from one another.  FIGS. 5A and 5B  illustrate a third embodiment of the invention which deploys four curved projections into the tissue. In this particular example, the curved projections may either be attached to the central rotatable element, or may be integrally formed with the central rotatable element.  FIGS. 6A and 6B  illustrate a fourth embodiment of the invention which deploys a single curved projection in the form of a wire attached at one end to the central rotatable element. Lastly,  FIGS. 7A and 7B  illustrate a fifth embodiment of the invention in which a suturing device includes needles and suture in operative relationships with the anchoring elements or projections. 
     Each of the four embodiments of the invention ( FIGS. 1A to 6B ) illustrate the present invention as incorporated into a catheter system. Thus, for clarity, each of  FIGS. 1A, 1B, and 4 to 6B  illustrates only a cut-out longitudinal section of a catheter system in which the present invention is incorporated.  FIGS. 3A and 3B  show a greater length of the catheter. As can be appreciated, the catheter extends upwardly and/or downwardly perpendicular from the page in  FIGS. 2A and 2B . 
     Referring first to  FIGS. 1A, 2A and 3A , a system  10  for securing a catheter system in a body lumen is provided. Sheath  12  has a pair of side openings  14  disposed on opposite sides thereof. A central rotatable element  20  is received within sheath  12 . A pair of projections  22 A and  22 B extend radially outwardly from rotatable element  20 , as shown in  FIGS. 1A, 2A and 3B . The sheath described herein may be a portion of a catheter body, an introducer sheath, or simply a hollow tubular body that is part of a device into which the present invention is incorporated. As will also be explained and illustrated, the present invention may be used in applications other than in a catheter body. For example, the present invention may be incorporated into a suturing device as shown in  FIGS. 7A and 7B . It is to be understood, however, that the present invention may be incorporated into other devices as well. 
     Returning to  FIGS. 1A, 2A and 3A , rotation of rotatable element  20  within sheath  12  in direction R ( FIG. 2A ) causes the distal ends of each of projections  22 A and  22 B to be pushed out through openings  14 . Thus, rotation of rotatable element  20  with respect to sheath  12  in direction R moves curved projections  22 A and  22 B from the pre-deployed position ( FIGS. 1A, 2A and 3A ) to the fully deployed position ( FIGS. 1B, 2B and 3B ). As can be seen in  FIG. 3B , such deployment causes curved projections  22 A and  22 B to extend beyond the edges E of side hole  11  in the wall W of body lumen L. Thus, curved projections  22 A and  22 B can act as an anchoring system, such that they will push against the interior surface of wall W when the catheter system  10  is pulled proximally in direction P. 
     It is to be understood that all reference herein made to rotation of the rotatable element (which is disposed within the sheath) both in the specification and claims, refers to rotation of the rotatable element with respect to the sheath. Thus, “rotation of the rotatable element” in the specification and claims, encompasses rotation of the rotatable element with the sheath held stationary, rotation of the sheath with the rotatable element held stationary, rotation of the sheath and rotatable element in opposite directions, and rotation of the sheath and rotatable element in the same direction, but at different speeds. 
     As can be appreciated, removal of the present anchoring system is accomplished by simply rotating rotatable element  20  with respect to sheath  12  in a direction opposite to R, thereby retracting curved projections  22 A and  22 B into the sheath. 
     As shown in  FIGS. 1A to 3B , curved projections  22 A and  22 B move through side openings  14  which are disposed on opposite sides of sheath  12 . Thus, in various embodiments, any number of side openings  14  may be disposed equidistantly around the circumference of sheath  12 . 
     Projections  22 A and  22 B may be curved. The projections preferably extend radially from the rotatable element in a plane that may be perpendicular or otherwise transverse to the longitudinal axis of the device or to the rotatable element. Specifically, the projections  22 A and  22 B move through side openings  14  as the projections are deployed in a radial direction with respect to the axis of the device. Such movement in the radial direction may preferably be confined to movement in the transverse plane defined by the lengths of the projections. 
     In the preferred embodiment illustrated in  FIGS. 1A to 3B , projections  22 A and  22 B are simply opposite ends of a single deformable member  22  which passes through a hole  21  in rotatable element  20 . Deformable member  22  (and its curved projections  22 A and  22 B) may be formed from a ribbon shaped material (having a rectangular cross section, as shown). Alternatively, deformable member  22  (and its curved projections  22 A and  22 B) may be formed from a wire (having a circular cross section). In further embodiments, deformable member  22  (and its curved projections  22 A and  22 B) may be formed from a member having an I-beam cross section. 
     An advantage of curved projections  22 A and  22 B being ribbon shaped or I beam shaped (or any other dimension in which they are thicker in the direction along the length of sheath  12 ) is that they are more resistant to bending when the catheter is pulled in direction P, such that the projections push against the tissue surrounding the interior of opening  11  through tissue wall W (see  FIG. 3B ). 
     It is to be understood that although curved projections  22 A and  22 B may be opposite ends of a single deformable member  22  (as shown), curved projections  22 A and  22 B may also be two separate elements which either are fastened to rotatable element  20  or are integrally formed from the same block of material as rotatable element  20 . Whether or not curved projections  22 A and  22 B are opposite ends of a single member, or are separate elements, such curved projections are preferably formed from a deformable material. Suitable deformable materials may include (but are not limited to) metals, including shape memory metals, polymers, or any combinations thereof 
     In optional preferred embodiments, curved projections  22 A and  22 B may be formed of a material which causes them to be biased such that their ends spring radially outwardly (i.e.: straighten out) as they pass through side openings  14 . An example of this effect can be seen in  FIG. 2B  where the curved radially extending ends of projections  22 A and  22 B are shown as being straighter than the center portion of deformable member  22  that is inside sheath  12 . This is advantageous in that it is the straightest portion of deformable member  22  protrudes radially away from the center of the device, and reaching farther, thus maximizing the amount of tissue against which the projections are anchored. 
     Optionally, curved projections  22 A and  22 B may be formed of a shape memory material (such as Nitinol). As such, curved projections  22 A and  22 B may thus be formed to spring radially outwardly (i.e.: straighten out) when they are exposed to a temperature change. For example, curved projections  22 A and  22 B could be exposed to a temperature change as they exit windows  14  by being warmed by the fluid passing through the body lumen. 
       FIG. 4  illustrates an embodiment of the invention having two pairs of curved projections. Specifically, a first pair comprising curved projections  22 A and  22 B, and a second pair comprising curved projections  24 A and  24 B. Thus, in this embodiment side openings  14  are also disposed longitudinally along the length of the sheath (as well as about the circumference of the shaft). As illustrated, curved projections  22 A and  22 B are opposite ends of a first deformable element  22  passing through hole  21 A while  24 A and  24 B are opposite ends of a second deformable element  24  passing through hole  21 B. 
       FIGS. 5A and 5B  illustrate yet another embodiment of the invention in which four curved projections  22 A,  22 B,  22 C and  22 D each extend from central rotatable element  20 . In this embodiment, four curved projections are used. It is to be understood however that, in accordance with the present invention, any plurality of curved projections can be used. These curved projections protrude through openings which may be disposed equidistantly around the circumference of shaft  12 . For example, curved projections  22 A,  22 B,  22 C and  22 D are shown as disposed at 90 degrees to one another. 
       FIGS. 6A and 6B  illustrate yet another embodiment of the invention in which a single curved projection  22 A is deployed through a single side opening  14 . In this embodiment, curved projection  22 A is one end of a wire (or other suitable deformable member)  22  which is wrapped around (and attached at one end to) central rotatable element  20 . In this embodiment, the length of wire  22  may optionally be as long, or longer than, deformable member  22  as shown in the other embodiments. Thus, wire  22  can be rotated such that its distal end (curved projection  22 A) is deployed much father through side opening  14  than is shown in the previous embodiments. This would have the effect of causing wire  22 , and its distal end (i.e. curved projection  22 A) to extend farther around the circumference of sheath  12 , thus firmly anchoring the present device in position.  FIGS. 6A and 6B  show wire  22  extending approximately half way around the circumference of the device. It is to be understood that the distal end of wire  22  (i.e. curved projection  22 A) may also—extend even further around the circumference of the device. For example, the distal end of wire  22  may be extended fully around the device, or even further (so that it wraps around the circumference of the device several times). 
     In various embodiments, the present invention is substantially enclosed within the body of the catheter, thus saving space and permitting easy access into the interior of body lumen L. 
     In various preferred embodiments, the present system is dimensioned to be around 5 to 10 mm in diameter, but may instead be dimensioned smaller so that it may fit into vessels less than 5 mm in diameter. 
     The various embodiments of the invention which are incorporated into a catheter system do not block fluid flow when anchoring a catheter in a body lumen. Thus, the present invention may conveniently be used in conjunction with systems either for drug or therapeutic energy delivery, or with diagnostic systems. 
     In an alternate embodiment, shown in  FIGS. 7A and 7B , the device is a suturing device  30  that is anchored on the interior side of a vessel wall through an arteriotomy. The device  30  may include suture-carrying or holding features located on extendable projections  32  in order to retrieve sutures S 1  and S 2  when device  30  provides an arteriotomy closure. In accordance with this embodiment, projections  32  are deployed radially outwardly in the same fashion that projections  22  were deployed in the previously described embodiments (eg: by rotating rotatable element  20  within device  30 ). 
     The suture-carrying features may be recesses formed in projections  32 . For example, the suture-carrying features may include cuffs  33  that may be attached to the ends SI and S 2  of a length of suture which runs through the center of device  30 . Cuffs  33  can be held within recesses in projections  32 . The present suture-carrying features may include cuffs, but the present invention is not so limited. For example, the ends of the suture can alternatively be formed into other features that are connectable to needles, such as loops. Suturing device  30  further comprises a pair of needles  34  that are initially disposed on an exterior of lumen L as shown in  FIG. 7A . Thereafter, needles  34  are advanced so that they pass through the wall of the vessel, such that each needle  34  is received into a cuff  33 . Thereafter, needles  34  are retracted, as shown in  FIG. 7B , each pulling a cuff  33  with a length of suture (Si or S 2 ) attached thereto out of the proximal end of device  30 . Thereafter, extendable projections  32  can be retracted radially inwardly (by rotating element  20  in an opposite direction) so that the distal end of device  30  may be removed from the hole in the side of the artery, leaving behind suture passing therethrough, which can be used to close the hole. It is to be understood that although device  30  is illustrated as having two needles  34 , cuffs  33  and sutures Si and S 2 , other embodiments having more needles, cuffs and sutures are also possible. As illustrated in  FIGS. 7A and 7B , the needles of such a device are would engage the cuffs and pull the suture through tissue.