Abstract:
An introducer for insertion of a medical device into a patient&#39;s vasculature includes an elongate introducer body, a hub, and a hemostatic valve. The elongate introducer body includes a longitudinal axis, a proximal region, a distal region, and an inner lumen. The hub is coupled to the proximal region of the introducer body. The hemostatic valve is disposed within the hub and forms a liquid-tight seal across the inner lumen. The introducer includes a guide configured to guide an object towards the center of the valve during insertion of the object.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 62/209,288, filed on Aug. 24, 2015, which is hereby incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Patients with cardiac ailments are sometimes treated with heart pumps adapted to be inserted into the heart through adjoining blood vessels and configured to assist the natural cardiac pump function or to replace natural cardiac pump function by a continuous pumping operation. 
         [0003]    In one common approach, an introducer sheath is used to gain vascular access prior to insertion of a medical device such as a heart pump. The introducer sheath includes a hemostatic valve that prevents blood leakage from the proximal end of the introducer sheath upon insertion of the introducer sheath into a blood vessel. The hemostatic valve should prevent excessive blood leakage when no objects are present in the valve or when guidewires, catheters, blood pumps, or other objects are inserted through the valve. One of the primary causes of excess leakage in an introducer sheath is damage to or perforation of the hemostatic valve. 
       SUMMARY 
       [0004]    Disclosed herein is an introducer sheath for percutaneous insertion of a heart pump. The introducer sheath includes a guide and a hemostatic valve. The introducer sheath guides an object towards the center of the hemostatic valve to reduce the risk of inadvertently puncturing the hemostatic valve during insertion of the object (e.g., a heart pump). Such inadvertent punctures could result when the object is inserted into the hemostatic valve at a position that is away/laterally offset from the center of the hemostatic valve or angularly offset from a central longitudinal axis of the hemostatic valve, thereby increasing the risk of damage to the hemostatic valve. The guide may be formed from the hemostatic valve or as a separate element. The systems, methods, and devices described herein reduce or eliminate the risk of valve perforation during insertion of medical devices (e.g., heart pumps), guidewires, dilators, or other objects by guiding inserted objects toward the center of the hemostatic valve. This can reduce or prevent blood leakage through the hemostatic valve. 
         [0005]    The hemostatic valve will additionally simplify user interaction with the introducer sheath. Current systems, methods, and devices may require a pre-requisite level of experience or attention from a user during a preparation phase, or during insertion of medical devices (e.g., heart pumps), guidewires, dilators, or other objects, However the proposed introducer sheath would improve ease of use with the system without requiring such pre-requisite levels of experience or attention from a user. Additionally, performance of the introducer sheath would be independent of the location on the hemostatic valve at which medical devices (e.g., heart pumps) are inserted. This minimizes human factor considerations and accommodates a wider range of use conditions, 
         [0006]    In one aspect, an introducer for insertion of a medical device into a patient&#39;s vasculature includes an elongate introducer body, a hub, and a hemostatic valve. The elongate introducer body includes a longitudinal axis, a proximal region, a distal region, and an inner lumen. The hub is coupled to the proximal region of the introducer body. The hemostatic valve is disposed within the hub and forms a liquid-tight seal across the inner lumen. The hemostatic valve includes a guide configured to guide an object towards the center of the valve during insertion of the object. The guide may be a funnel. In some implementations, the hemostatic valve has a proximal surface and a distal surface, and the funnel is defined by sloped regions of the proximal surface of the hemostatic valve. The funnel may be separate from the hemostatic valve. The sloped regions may be angled about 30°, about 45°, about 60°, or greater relative to the plane perpendicular to the longitudinal axis of the introducer body, In certain implementations, the proximal surface includes a fiat central region that is substantially perpendicular to the longitudinal axis of the elongate introducer body. The flat central region may have a diameter of about 3 mm or less, In some implementations, the introducer is configured to part along a parting surface substantially parallel to the longitudinal axis of the introducer body. In certain implementations, the hemostatic valve is configured to part along a parting surface substantially parallel to the longitudinal axis of the introducer body. The hemostatic valve may include a central void that reduces the stiffness of the center of the hemostatic valve. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The foregoing and other objects and advantages will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
           [0008]      FIGS. 1 and 2  show cross-section views of an introducer assembly including a funnel valve according to certain embodiments; 
           [0009]      FIG. 3  shows a perspective view of the introducer assembly of  FIGS. 1 and 2 ; 
           [0010]      FIG. 4  shows percutaneous insertion of a heart pump using the introducer assembly of  FIGS. 1 and 2 ; 
           [0011]      FIGS. 5 and 6  show parting of the introducer assembly of  FIGS. 1 and 2 ; and 
           [0012]      FIGS. 7 and 8  show cross-section views of an alternate introducer assembly including a funnel valve according to certain embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    To provide an overall understanding of the systems, method, and devices described herein, certain illustrative embodiments will be described. Although the embodiments and features described herein are specifically described for use in connection with introducer sheaths and hemostatic valves for percutaneous insertion of heart pumps, it will be understood that all the components and other features outlined below may be combined with one another in any suitable manner and may be adapted and applied to other types of introducer sheaths and hemostatic valves or other types of cardiac assist devices, including balloon pumps. 
         [0014]    The apparatus described herein provides an introducer sheath and a hemostatic valve for percutaneous insertion of a heart pump. The introducer sheath includes a guide and a hemostatic valve. The introducer sheath guides an object towards the center of the hemostatic valve to reduce the risk of inadvertently puncturing the hemostatic valve during insertion of the object (e.g., a heart pump). The guide may be formed from the hemostatic valve or as a separate element. The systems, methods, and devices described herein thus reduce or eliminate the risk of valve perforation during insertion of medical devices (e.g., heart pumps), guidewires, dilators, or other objects. This can reduce or prevent blood leakage through the hemostatic valve. 
         [0015]      FIGS. 1 and 2  show cross-section views of an introducer assembly  100  including a funnel valve according to certain embodiments. The introducer assembly  100  includes an elongate introducer body  106 , a hub  102 , and a hemostatic valve  104 . The elongate introducer body  106  has an inner lumen  107  and a longitudinal axis  108 . The hub  102  includes a first hub portion  102   a,  a second hub portion  102   b,  a first wing  103   a,  and a second wing  103   b.  The hemostatic valve  104  includes a first hemostatic valve portion  104   a,  a second hemostatic valve portion  104   b,  a guide  110 , a distal surface  111 , a proximal surface  112 , a sloped region  113 , a flat region  114 , an outer region  120 , a parting surface  116 , and a central void  118 . 
         [0016]    The hemostatic valve  104  creates a liquid tight seal across the inner lumen  107  of the elongate introducer body  106 . The guide  110  of the hemostatic valve  104  guides objects inserted into the hemostatic valve  104  such that the objects are guided to the central flat region  114 . This reduces the risk of inadvertently puncturing the hemostatic valve  104  during insertion of an object (e.g., a heart pump). The guide  110  includes a first guide portion  110   a  and a second guide portion  110   b.  The guide  110  is formed by the proximal surface  112  of the hemostatic valve  104 , The proximal surface  112  includes the sloped region  113 , which defines the funneled shape of the guide  110 , and the central flat region  114 . The sloped region  113  is angled relative to the central flat region  114  by a funnel angle  117 . The funnel angle  117  is about  30 ″. In some implementations, the funnel angle is about 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or any other suitable angle. The funnel angle  117  is suitably steep to guide inserted objects towards the central flat region  114  The funnel angle  117  is shown as substantially constant in  FIG. 1 , but the person of ordinary skill will appreciate that the funnel angle can flare or vary over the length of the sloped region  113 . The central flat region  114  of the hemostatic valve has a diameter  115 . The diameter  115  may be 1 cm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, less than 1 mm, or any other suitable dimension. The guide  110  may have different surface properties, durometer, material, or other properties compared to the remainder of hemostatic valve  104 . For example, the guide  110  may be more rigid, tougher, or harder, relative to the remainder of hemostatic valve  104 . Although the guide  110  is shown in  FIG. 1  as being formed in the hemostatic valve  104 , in some embodiments the guide  110  is separate from the hemostatic valve  104 . For example, the guide  110  may be formed in the hub  102 . 
         [0017]    The hemostatic valve  104  is formed of the first hemostatic valve portion  104   a  and the second hemostatic valve portion  104   b.  The first hemostatic valve portion  104   a  and the second hemostatic valve portion  104   b  are held together by the hub  102  and interface at the parting surface  116 . The parting surface  116  separating the first hemostatic valve portion  104   a  and the second hemostatic valve portion  104   b  allow the hemostatic valve  104  to be completely separated after insertion of an object. The first hemostatic valve portion  104   a  is connected to the first hub portion  102   a  at the outer region  120   a,  and the second hemostatic valve portion  104   b  is connected to the second hub portion  102   b  at the outer region  120   b.  The connection between the hub  102  and the hemostatic valve  104  may be an interference fit, an adhesive bond, a connection by a mechanical fastener, or any other suitable connection. The parting surface  116  also defines a central void  118 . The central void  118  reduces the stiffness of the hemostatic valve  104  in the central flat region  114 . This may allow the valve to easily give or to deform in the central flat region  114  when an object is inserted. This may also allow the hemostatic valve  104  to form a double seal against an object inserted through the hemostatic valve  104 . A double seal may provide redundancy, thereby decreasing the risk of valve leakage or failure. 
         [0018]    The hemostatic valve  104  is coupled to the elongate introducer body  106  the huh  102 . Similar to the hemostatic valve  104 , the hub  102  is split along the parting surface  116  into the first hub portion  102   a  and the second hub portion  102   b.  The first and second wings  103   a - b  provide a lever arm that allows the hub  102  to be manually split into the first hub portion  102   a  and the second hub portion  102   b.  This splitting may facilitate the replacement of the introducer assembly  100  with another assembly or sheath during the use of a heart pump. Splitting of the hub  102  also initiates splitting of the elongate introducer body  106  into two parts so that the entire introducer assembly  100  can be removed as will be discussed further in relation to  FIGS. 5 and 6 . The elongate introducer body  106  has an outer diameter sized for percutaneous insertion. In some implementations, the outer diameter of the elongate introducer body  106  is 10 French (3.33 mm), 11 French (3.67 mm), 12 French (4 mm), 13 French (4.33 ram), 14 French (4.67 mm), 15 French (5 mm), 16 French (5.33 mm), 17 French (5.67 mm), 18 French (6 mm), 19 French (6.33 mm), 20 French (6.67 mm), 21 French (7 mm), or any other suitable diameter. 
         [0019]      FIG. 3  shows a perspective view of the introducer assembly of  FIGS. 1 and 2 . The introducer assembly  100  includes the elongate introducer body  106 , the hub  102 , the hemostatic valve  104 , a reinforcing ring  150 , and a fluid line  152 . The hub  102  includes the first hub portion  102   a,  the second hub portion  102   b,  the first wing  103   a,  and the second wing  103   b.  The hemostatic valve  104  includes the proximal surface  112  having the sloped region/ 13  and the central flat region  114 . The fluid line  152  allows the inner lumen  107  (not shown) to be flushed with saline or any other biocompatible fluid to prevent stagnation of blood or blood clot formation in the introducer assembly  100 . The reinforcing ring  150  connects the first hub portion  102   a  and the second hub portion  102   b.  The reinforcing ring  150  may prevent inadvertent or premature separation of the first and second portions  102   a - b  of the hub  102 . For example, the reinforcing ring  150  may be tougher or stronger than the hub  102  to prevent separation. In some implementations, the reinforcing ring  150  and the tubular sheath body  106  are the only elements of the introducer assembly  100  that are not parted before use. In such an implementation, after the reinforcing ring  150  is separated, no other element holds the first hub portion  102   a  and the second hub portion  102   b  together. Separation of the introducer assembly  100  may be more predictable if separation depends on fewer elements. 
         [0020]      FIG. 4  shows percutaneous insertion of a heart pump assembly  200  using the introducer assembly of  FIGS. 1 and 2 . The heart pump assembly  200  includes a distal end portion  203  and a supply catheter  202 . The sheath assembly  100  includes the hemostatic valve  104  and the fluid supply line  152 . The fluid supply line  152  may be used to flush the introducer assembly  100  before during or after insertion of the heart pump assembly  200 . In some implementations, the supply catheter  202  of the heart pump assembly  200  includes a flexible drive shaft. The distal end portion  203  of the heart pump assembly  200  is inserted into the introducer assembly  100  along an insertion path  204 . The insertion path  204  forms an angle of insertion  206  relative to the longitudinal axis  108  of the introducer assembly  100 . The guide (not shown)of the introducer assembly  100  limits the angle of insertion  206  to prevent puncture of the hemostatic valve  104  during insertion of the heart pump assembly  200 . The guide may limit the angle of insertion  206  to less than 90°, less than 80°, less than 70°, less than 60°, less than 50°, less than 45°, less than 40°, less than 35°, less than 30°, less than 25°, less than 20°, less than 15°, less than 10°, less than 5°, or to any other suitable angle. 
         [0021]      FIGS. 5 and 6  show parting of the introducer assembly of  FIGS. 1 and 2 . After the heart pump assembly  200  (not shown in  FIGS. 5 and 6 ) has been inserted into the patient, the introducer assembly  100  is separated along a parting surface while remaining on the supply catheter  202 . A healthcare professional applies force to the first and second wings  103   a - b  to part (e.g., “peel-away”) the introducer assembly  100 . This separates the hub  102  into a first hub portion  102   a  and a second hub portion  102   b.  This also separates the hemostatic valve  104  into a first hemostatic valve portion  104   a  and a second hemostatic valve portion  104   b.  This also initiates a crack  105  in the proximal region of the elongate introducer body  106 . The crack  105  is advanced by pulling the first hub portion  102   a  and the second hub portion  102   b  farther apart as shown in  FIG. 6 . This process may continue until the introducer assembly  100  is completely split and separated from the supply catheter  202 . This allows another sheath (not shown) to be advanced over the supply catheter  202  into the patient. 
         [0022]      FIGS. 7 and 8  show an alternate introducer assembly  300 . The introducer assembly  300  includes an elongate introducer body  306 , a hub  302 , and a hemostatic valve  304 . The elongate introducer body  306  has an inner lumen  307  and a longitudinal axis  308 . The hub  302  includes a first hub portion  302   a,  a second hub portion  302   b,  a first wing  303   a,  and a second wing  303   b . The hemostatic valve  304  includes a first hemostatic valve portion  304   a,  a second hemostatic valve portion  304   b,  a distal surface  311 , a proximal surface  312 , a parting surface  316 , and a central void  318 . 
         [0023]    introducer assembly  300 , the distal surface  311  and the proximal surface  312  of the hemostatic valve  304  are both substantially flat. A hemostatic valve  304  having a substantially flat profile would less material and complexity to manufacture and implement. The hub  302  also includes a bracket  325  comprising a first bracket portion  325   a  and a second bracket portion  325   b.  A guide  310  is integrally formed with the bracket  325  and comprises a first guide portion  310   a  and second guide portion  310   b  that define a central opening  314 . The bracket  325  substantially encompasses the hemostatic valve  304  such that a portion  320   a  and  320   b  of the proximal surface  312  of the hemostatic valve  304  is in contact with the guide portions  310   a  and  310   b  of the bracket  325 . In this configuration, the guide  310  exposes a portion of the substantially flat proximal surface  312  of the hemostatic valve  304  in the vicinity of the central opening  314 . 
         [0024]    The guide  310  includes a sloped region  313 , which defines the funneled shape of the guide  310  and the central opening  314 , which, in turn, exposes the substantially flat proximal surface  312  of the hemostatic valve  304 . The guide  310  is therefore able to guide objects towards the central opening  314  and hence the proximal surface  312  of hemostatic valve  304 . The sloped region  313  is angled relative to the exposed flat proximal surface  312  of the hemostatic valve  304  by a funnel angle  317 . The funnel angle  317  is about  30 °, In some implementations, the funnel angle  317  is about 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or any other suitable angle. The funnel angle  317  is suitably steep to guide inserted objects towards the central opening  314  and the flat proximal surface  312  of the hemostatic valve  304 . The funnel angle  317  is shown as substantially constant in  FIG. 8 , but the person of ordinary skill will appreciate that the funnel angle  317  can flare or vary over the length of the sloped region  313 . It will also be understood that while the guide  310  in  FIG. 8  is shown to have a substantially linear profile, any other suitable profile may be implemented (e.g., a concave downward profile). The central opening  314  of the hemostatic valve has a diameter  315 , The diameter  315  may be 1 cm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, less than 1 mm, or any other suitable dimension. The bracket  325  may have different surface properties, durometer, material, or other properties compared to the hub  302  or the hemostatic valve  304 . For example, the bracket  325  may be more rigid, tougher, or harder, relative to the hub  302  or the hemostatic valve  304 . 
         [0025]    The hemostatic valve  304  is formed of the first hemostatic valve portion  304   a  and the second hemostatic valve portion  304   b.  The first hemostatic valve portion  304   a  and the second hemostatic valve portion  304   b  are held together by the bracket  325  in the hub  302  and interface at the parting surface  316 . The parting surface  316  separating the first hemostatic valve portion  304   a  and the second hemostatic valve portion  304   b  allow the hemostatic valve  304  to be completely separated after insertion of an object. The first hemostatic valve portion  304   a  is connected to the first bracket portion  325   a  at the portion  320   a  of the proximal surface  312  of the hemostatic valve  304 , while the second hemostatic valve portion  304   b  is connected to the second bracket portion  325   b  at the portion  320   b  of the proximal surface  312 . The connection between the bracket  325  and the hemostatic valve  304  may be an interference fit, an adhesive bond, a connection by a mechanical fastener, or any other suitable connection. The parting surface  316  also defines a central void  318 . The central void  318  reduces the stiffness of the hemostatic valve  304  in the vicinity of the central opening  314 . This may allow the valve to easily give or to deform in the vicinity of the central opening  314  when an object is inserted. This may also allow the hemostatic valve  304  to form a double seal against an object inserted through the hemostatic valve  304 . A double seal may provide redundancy, thereby decreasing the risk of valve leakage or failure. 
         [0026]    Similar to the hemostatic valve  304 , the hub  302  and bracket  325  are split along the parting surface  316  into the first hub portion  302   a  and first bracket portion  325   a,  and the second hub portion  302   b  and second bracket portion  325   b.  The first and second wings  303   a - b  provide a lever arm that allows the hub  302  and guide  310  to be manually split into the first hub portion  302   a  the first bracket portion  325   a,  and the second hub portion  302   b  and the second bracket portion  325   b.  This splitting may facilitate the replacement of the introducer assembly  300  with another assembly or sheath during the use of a heart pump. Splitting of the hub  302  also initiates splitting of the elongate introducer body  306  into two parts so that the entire introducer assembly  300  can be removed as previously discussed in relation to  FIGS. 5 and 6 . 
         [0027]    The reinforcing ring  150  discussed in relation to  FIGS. 1 to 3  can also be used with the introducer assembly  300  to connect the hub portions  302   a - b  and the bracket portions  325   a - b . The reinforcing ring  150  may prevent inadvertent or premature separation of the first and second portions  302   a - b  of the hub  302  and the first and second portions  325   a - b  of the bracket  325 . For example, the reinforcing ring  150  may be tougher or stronger than the hub  302  to prevent separation. In some implementations, the reinforcing ring  150  and the tubular sheath body  306  are the only elements of the introducer assembly  300  that are not parted before use. In such an implementation, after the reinforcing ring  150  is separated, no other element holds the first and second hub portions  302   a - b  and the first and second bracket portions  325   a - b  together. 
         [0028]    In a further alternate implementation, the guide portion  310  may be located in the reinforcing ring  150 . 
         [0029]    The foregoing is merely illustrative of the principles of the disclosure, and the apparatuses can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation. It is to be understood that the apparatuses disclosed herein, while shown for use in percutaneous insertion of heart pumps, may be applied to apparatuses in other applications requiring hemostasis. 
         [0030]    Variations and modifications will occur to those of skill in the art after reviewing this disclosure. The disclosed features may be implemented, in any combination and subcombination (including multiple dependent combinations and subcombinations), with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated in other systems. Moreover, certain features may be omitted or not implemented. 
         [0031]    Examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the scope of the information disclosed herein. All references cited herein are incorporated by reference in their entirety and made part of this application.