Patent Publication Number: US-2015088153-A1

Title: Slotted introducer needle and method for accessing a body lumen

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 12/724,278, filed Mar. 15, 2010, the entirety of which is incorporated by this reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to medical devices, and more particular to device, apparatus, and methods for accessing a body lumen. 
     BACKGROUND OF THE INVENTION 
     Catheterization and interventional procedures, such as angioplasty or stenting, generally are performed by inserting a hollow needle through a patient&#39;s skin and tissue into the vascular system. A guide wire may be advanced through the needle and into the patient&#39;s blood vessel accessed by the needle. The needle is then removed, enabling an introducer sheath to be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to a dilator. 
     A catheter or other device may then be advanced through a lumen of the introducer sheath and over the guide wire into a position for performing a medical procedure. Thus, the introducer sheath may facilitate introducing various devices into the vessel, while minimizing trauma to the vessel wall and/or minimizing blood loss during a procedure. 
     Upon completing the procedure, the devices and introducer sheath are then removed, leaving a puncture site the size of the needle in the vessel wall. Traditionally, external pressure is then applied to the puncture site until clotting and wound sealing occur. Accordingly, the patient must remain bedridden for a substantial period of time after clotting to ensure closure of the wound. This procedure may be time consuming and expensive, requiring as much as an hour of a physician&#39;s or nurse&#39;s time. It is also uncomfortable for the patient and requires that the patient remain immobilized in the operating room, catheter lab, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs. 
     BRIEF SUMMARY 
     An introducer needle for accessing a body lumen includes an annular-shaped body having a distal end and a proximal end, a leading edge formed on the distal end, and a slot defined in the leading edge and extending proximally from the distal end. 
     In at least one example, the slot can be include a first edge and a second edge, the first edge and the second edge each extending proximally from the leading edge and being separated by a central angle greater than 90 degrees and less than 360 degrees. The first end and the second edge are in continuous communication with the leading edge. 
     A method of accessing a body lumen can include cutting an incision in a body lumen wall in which the incision having a first end and a second end, the first end and the second end being separated by a central angle of less than 360 degrees. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific examples thereof that are illustrated in the appended drawings. Understanding that these drawings depict only typical examples of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings. 
         FIG. 1  is a flowchart illustrating a method of accessing a body lumen according to one example; 
         FIG. 2A  is a perspective view of a slotted introducer needle according to one example; 
         FIG. 2B  illustrates a plan view of a slotted introducer needle according to one example; 
         FIG. 2C  illustrates a cross-sectional view of the slotted introducer needle of  FIG. 2B  taken along section  2 C- 2 C; 
         FIGS. 2D-2E  illustrate an angle between the central axis and the leading edge; and 
         FIGS. 3A-3E  illustrate a method of accessing a body lumen with a slotted introducer needle according to one example. 
     
    
    
     It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like-reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of examples of the present invention. 
     DETAILED DESCRIPTION 
     Devices and methods are disclosed herein for providing access to a body lumen. For example, a tract is cut into the tissue to provide access to the body lumen wall at an access point. At the access point, a flap is cut into the body lumen wall. The flap provides an opening through which medical devices can access the body lumen to perform a medical procedure. Once the medical procedure is complete pressure in the body lumen can return the flap to proximity with the body lumen wall thereby allowing the flap to cover a substantial portion of the opening used to access the body lumen. As a result, the flap reduces the surface area to be sealed to established hemostasis from the body lumen. 
     The flap can be held in place by a plug of material inserted into the tissue tract. The plug in turn can be held in place as desired by a topical patch. Maintaining the flap to cover a substantial portion of the opening can reduce the surface area of the wound to be healed to the area between the flap and the rest of the body lumen wall. Reducing the surface area of the wound in turn can reduce the healing time associated with accessing the body lumen. 
     Any device or method can be used to cut the flap in the body lumen. In at least one example, the flap can be cut with a slotted introducer needle that includes an annular-shaped body and a distal tip. A slot can be defined in the distal tip and/or the annular-shaped body that extends proximally of the distal tip. In at least one example, the slot allows the introducer needle to cut the flap in a body lumen wall. 
       FIG. 1  is a flowchart introducing a method for accessing a body lumen. The method can include providing an access tract to an access point at the body lumen wall, as represented by block  100 . In at least one example, assessing the tract can include cutting the tissue to provide the tract. The access point can be at any desired location to access any desired body lumen through any body lumen wall. 
     Following providing the access tract, the method can include cutting a flap in the body lumen wall, as represented by block  110 . Cutting a flap can include making an incision in the body lumen wall that has an open shape. The resulting flap can include a base end that remains connected to the body lumen wall and a tag end that is free from the rest of the body lumen wall. In such a process, a base portion of the flap will remain attached to the body lumen wall while the rest of the flap will be able to move relative to the body lumen wall. Cutting a flap can provide an access opening of a suitable size while reducing the surface area of the wound after the procedure to the perimeter of the flap rather than the entire area of the opening as will be discussed in more detail below. 
     The flap can be cut by any method or process using any device or devices. In at least one example, a slotted introducer needle similar to those described below can be used to cut the flap in the body lumen wall. Further, the flap can be cut in one or more steps using one or more devices. For ease of reference, a process will be described in which the flap is cut in a single step by a single device. 
     Continuing with the method of  FIG. 1 , once the flap has been cut in the body lumen wall, the body lumen can be accessed at the body lumen as represented by block  120 . In particular, medical devices can be inserted into the body lumen by way of the opening formed by the flap to perform a medical procedure. Any number of medical devices can access the body lumen wall to perform any number and types of medical procedures. 
     Once the medical procedure(s) is complete, the devices are removed from the body lumen, and a plug can be inserted into the tissue tract, as represented by block  130 . In at least one example, the plug can be formed of a bioabsorbable material. The plug can help establish hemostasis by blocking the flow of blood or other fluid that may flow through the incision between the flap and the rest of the body lumen wall. In particular, the surface area through which the body fluid can flow out of the body lumen wall can be reduced to the space between the incision and the flap as the flap is returned to a position adjacent the body lumen wall. 
     An optional topical patch can also be applied over the plug, as represented by block  140 . The topical patch can help maintain the plug in communication with the flap as well as containing any bodily fluid that may seep through the plug. Accordingly, a process for accessing a body lumen has been introduced in which a flap is cut into a body lumen wall to provide access to a body lumen. Cutting a flap can simultaneously provide an effective opening of sufficient size to provide the desired access while reducing the surface area of the wound that is left to seal to the perimeter of the incision used to cut the flap. Reducing the surface area left to be sealed can allow the wound to seal more quickly. 
       FIG. 2A  illustrates a perspective view of a slotted introducer needle  200  configured to cut a flap in a body lumen wall. The slotted introducer needle  200  can include an annular-shaped body  210  having a distal end  210 A and a proximal end  210 B. A central lumen  220  extends through the annular-shaped body  210  that includes a central axis  230 . The slotted introducer needle  200  also includes a leading edge  240  on the distal end  210 A of the annular-shaped body  210 . A slot  250  is formed in the distal end  210 A of the annular-shaped body  210 . The slot  250  provides a gap in the leading edge  240  as it is brought into contact with a body lumen wall. The gap in the leading edge  240  in contact with a body lumen wall in turn can allow the slotted introducer needle  200  to cut a flap in the body lumen wall  340  ( FIG. 3A ). 
     As shown in  FIG. 2B , the slot  250  can defined by the space between edges  260 ,  270  that extend proximally from the distal tip  210 A. In at least one example, the edges  260 ,  270  can be generally parallel. Further, the edges  260 ,  270  can be generally parallel to the central axis  230 . In the illustrated example, the slot  250  can end distal of the proximal end  210 B, such as at a slot terminus  280 . The slot terminus  280  connects the edges  260 ,  270 . As a result, at least a portion of the annular-shaped body  210 , including the distal end  210 A and a portion of the distal end  210 A proximal the distal end  210 A, have an open and/or discontinuous cross-section. 
       FIG. 2C  illustrates a cross sectional view of the annular-shaped body  210  adjacent the distal end  210 A ( FIGS. 2A ,  2 B) that has an open and/or discontinuous cross section. In such an example, the annular-shaped body  210  has a central angle  280  that is greater than 90 degrees but less than  360  as taken internally between the edges  260 ,  270 . For example, the central angle  280  can be greater than 180 degrees and less than 360 degrees, such as less than about 270 degrees. In the illustrated example, the annular-shaped body  210  has a generally arc-shaped cross section. 
     It will be appreciated that the annular-shaped body  210  and the distal end  210 A in particular can have any cross-sectional shape in which a slot  250  is defined in the leading edge and extends proximally from the leading edge into the annular-shaped body. For example, the distal end can have a rounded rectangular section having a generally U-shaped profile, C-shaped profile or any other section with rounded corners. The distal end  210 A can also have any combination of curved and/or straight sections to define a slot, including profiles having sharp corners. Thus, although an annular-shaped body may be circular, it may include other noncircular shapes as well, such as elliptical or other shapes that are asymmetrical about a central axis. In other examples, the annular-shaped body  210  may include other shapes and/or may not have a central axis. 
     It will also be appreciated that while a parallel-edged slot is described that is also generally parallel to the central axis of the lumen defined by the annular-shaped body, other configurations are possible in which one or more of the edges are curved and/or otherwise non-linear and/or in which the edges that define the slot are oriented at some angle relative to the central axis. 
     Further, in the illustrated example the leading edge  240  is generally perpendicular to the central axis  230  and is also generally planar. It will be appreciated that the leading edge  240  can have any shape, including any combination of curved and/or straight portions that can also be oriented at any angle relative to the central axis  230 , as illustrated in  FIGS. 2D-2E . 
     In particular,  FIG. 2D  illustrates an angle  290  between the central axis  230  and the leading edge  240 . The angle  290  shown is such that the leading edge  240  angles proximally away from the slot  250  formed in the annular-shaped body  210 .  FIG. 2E  illustrates the leading edge  240  oriented so as to form an angle  290 ′ between the central axis  230  and the ledge edge  240 . In the example illustrated in  FIG. 2E , the leading edge  240  angles distally away from the slot  250  formed in the annular shaped body  210 . Accordingly, the distal end  210 A can have any combination of shapes and orientations in which a slot is defined in the leading edge  240  and extends proximally away from the leading edge  240 . Such a configuration can allow the slotted introducer device to cut a slot in a body lumen wall as part of a medical procedure. 
       FIGS. 3A-3E  illustrate a method of accessing a body lumen according to one example. As illustrated in  FIG. 3A , a body lumen  300  can be accessed at a desired access point  310  by cutting a tissue tract  320  in tissue  330  adjacent a body lumen wall  340  of the body lumen  300 . This can be achieved by the slotted introducer needle  200  or any other device or apparatus can be used to cut the tissue tract  320  as desired, such as a cutting cannula or other cutting device. 
     As shown in  FIG. 3B , the slotted introducer needle  200  can be advanced through the tissue tract  320  ( FIG. 3A ) until the leading edge  240  of the distal end  210 A is in contact with the body lumen wall  340 . The slotted introducer needle  200  can then be advanced distally to cause the lead edge  240  to cut an incision through the body lumen wall  340 , and pass at least painfully into the body lumen at the access point  310 . 
     An incision  350  in the body lumen wall  340  is shown in  FIG. 3C . As shown in  FIG. 3C , the incision  350  includes ends  350 A,  350 B that are separated by a central angle  352  that is less than 360 degrees. Accordingly, the incision  350  defines a flap  360 . The flap  360  can include a base portion  370  and a tag end  380 . The base portion  370  remains attached to the rest of the body lumen wall  340 . In such an example, the flap  360  can be moved to provide an opening having a size approximately equal to the area circumscribed by the incision  350  and a chord  355  across the base portion  370  of the flap  360 . 
     As illustrated in  FIG. 3D , once the flap  360  has been formed or cut, the flap  360  can be urged into the body lumen  300  to expand the incision to provide access through the body lumen wall  340 . For example, an instrument  385 , such as a medical device, can then be introduced to the body lumen  300  as shown in  FIG. 3D . In the illustrated example, the instrument  385  is passed through the slotted introducer needle  200 . It will be appreciated that the instrument  385  can be passed through the flap  360  in any manner to perform a medical procedure or procedures. Once the medical procedure is complete, the instrument  385  can be removed. 
     In at least one example, a flow of fluid through the body lumen  300  and/or pressure associated with the flow of fluid can urge the flap  360  toward the rest of the lumen wall  340 , as shown in  FIG. 3E  after the instrument  385  ( FIG. 3D ) and the slotted introducer needle  200  are removed. Stated another way, the flap  360  is orientated substantially in a direction of the flow of the fluid within the body lumen  300  such that the base portion  370  is located upstream of the free portion, such as the tag end  380 . A plug  390  can be inserted into the tissue tract  320  ( FIG. 3A ) to provide hemostasis. In at least one example, the plug  390  can be formed of a bio-absorbable material. Biodegradable or bioabsorbable, as defined herein, means the composition will degrade or erode in vivo to form smaller chemical species. Degradation can result, for example, by enzymatic, chemical, and physical processes. Suitable biocompatible, biodegradable polymers include, for example, poly(lactide)s, poly(glycolide)s, poly(lactide-co-glycolide)s, poly(lactic acid)s, poly(glycolic acid)s, poly(lactic acid-co-glycolic acid)s, polyanhydrides, polyorthoesters, polyetheresters, polycaprolactone, polyesteramides, blends and copolymers thereof. 
     An optional topical patch  395  can then be placed over the plug  390  as desired. Any conventional and/or self-adhesive pad may be applied. Additional benefit can be achieved through the application of a pad chemically treated or including substances that attract the negatively charged red place cells and platelets, effects vasoconstriction, and/or forms a strong clot. Such substances can include, without limitation, Chitosan and thrombin. In such an example, the surface area of the body lumen wall  340  left to be sealed can be reduced as the tag end  380  can return to proximity with the rest of the body lumen wall  340 . Accordingly, the surface area to be sealed can correspond to a gap between the body lumen wall  340  and the flap  360 , which can be approximately equal to the surface area of the incision  350  ( FIG. 3C ) rather than the effective size of the opening described above. A relative smaller area to be sealed can allow the access point  310  ( FIG. 3A ) to seal in a relatively short time. 
     The invention is susceptible to various modifications and alternative means, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular devices or methods disclosed, but to the contrary; the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the claims.