Patent Publication Number: US-2023149690-A1

Title: Bypass sheath

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to Provisional Application No. 63/280,446, filed Nov. 17, 2021, which is herein incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the field of introducer sheaths for use in the delivery of percutaneous devices. Specifically, the present disclosure relates to a bypass sheath for use in the intravascular delivery of percutaneous devices. 
     BACKGROUND 
     In various procedures, for example procedures for delivering percutaneous medical devices, an introducer sheath is introducer into a blood vessel of a patient, for example a femoral artery, and the medical devices to be inserted through the blood vessel are inserted into the introducer sheath for introduction into the blood vessel. To provide sufficient volume for introducing the devices, the introducer sheath may have the same, or almost the same, diameter as the blood vessel. As such, the introducer sheath may substantially reduce or essentially block the blood flow through the blood vessel while the introducer sheath is placed within the artery, which can cause various detrimental effects on the patient. 
     SUMMARY 
     In Example 1, an introducer sheath for use in delivering devices includes a proximal portion opposite a distal portion and a body portion extending between the proximal portion and the distal portion, the body portion defining a lumen of the introducer sheath configured for receiving at least one device, at least one bypass opening positioned in the proximal portion of the introducer sheath such that the bypass opening extends from an exterior of the introducer sheath to the lumen of the introducer sheath, and at least one plug positioned within the lumen of the introducer sheath and configured to inhibit the flow of blood into the lumen proximal of the plug. 
     In Example 2, the introducer sheath of Example 1 further includes wherein the at least one bypass opening includes a plurality of bypass openings arranged at the proximal portion of the introducer sheath. 
     In Example 3, the introducer sheath of Example 1 further includes wherein the at least one plug is positioned directly adjacent the at least one bypass opening in a direction proximal to the at least one bypass opening. 
     In Example 4, the introducer sheath of Example 2 further includes wherein the at least one plug is positioned directly adjacent a proximal most bypass opening of the plurality of bypass openings. 
     In Example 5, the introducer sheath of Example 1 further includes wherein the at least one plug is composed of silicone. 
     In Example 6, the introducer sheath of Example 1 further includes wherein the at least one plug has a radiopaque coating. 
     In Example 7, the introducer sheath of Example 1 further includes wherein the at least one plug is composed of a radiopaque material. 
     In Example 8, the introducer sheath of Example 1 further includes wherein the at least one bypass opening is lined by a radiopaque material. 
     In Example 9, the introducer sheath of Example 1 further includes wherein the at least one plug comprises a central opening for sealingly engaging with a catheter positioned within the introducer sheath. 
     In Example 10, the introducer sheath of Example 9 further includes wherein the central opening is composed of a plurality of slits. 
     In Example 11, a method for delivering a device into a patient includes inserting an introducer sheath into a vessel of the patient, the introducer sheath including a proximal portion opposite a distal portion, a body portion extending between the proximal portion and the distal portion and the body portion defining a lumen, and at least one bypass opening arranged at the proximal portion of the introducer sheath. The method further includes inserting the device into the introducer sheath and advancing the device to a target position in the patient and inserting a plug into the introducer sheath arranged such that the plug is positioned adjacent to and proximally relative to the at least one bypass opening to inhibit the flow of blood into the lumen proximal of the plug. 
     In Example 12, the method of Example 11 further includes wherein removing the plug from the introducer sheath and removing the percutaneous circulatory support device through the introducer sheath. 
     In Example 13, the method of Example 11 further includes wherein the at least one bypass opening includes a plurality of bypass openings and the plug is positioned proximally of a proximal-most bypass opening of the plurality of bypass openings. 
     In Example 14, the method of Example 11 further includes wherein the at least one plug having a central opening for sealingly engaging with a catheter positioned within the introducer sheath. 
     In Example 15, the method of Example 14 further includes wherein the central opening is composed of a plurality of slits. 
     In Example 16, an introducer sheath for use in delivering percutaneous devices, the introducer sheath including a proximal portion opposite a distal portion and a body portion extending between the proximal portion and the distal portion, the body portion defining a lumen of the introducer sheath configured for receiving at least one percutaneous device, at least one bypass opening positioned in the proximal portion of the introducer sheath such that the bypass opening extends from an exterior of the introducer sheath to the lumen of the introducer sheath, and at least one plug positioned within the lumen of the introducer sheath and configured to inhibit the flow of blood into the lumen proximal of the plug. 
     In Example 17, the introducer sheath of Example 16 further includes wherein the at least one bypass opening includes a plurality of bypass openings arranged at the proximal portion of the introducer sheath. 
     In Example 18, the introducer sheath of Example 16 further includes wherein the at least one plug is positioned directly adjacent the at least one bypass opening in a direction proximal to the at least one bypass opening. 
     In Example 19, the introducer sheath of Example 17 further includes wherein the at least one plug is positioned directly adjacent a proximal-most bypass opening of the plurality of bypass openings. 
     In Example 20, the introducer sheath of Example 16 further includes wherein the at least one plug is composed of silicone. 
     In Example 21, the introducer sheath of Example 16 further includes wherein the at least one plug has a radiopaque coating. 
     In Example 22, the introducer sheath of Example 16 further includes wherein the at least one plug is composed of a radiopaque material. 
     In Example 23, the introducer sheath of Example 16 further includes wherein the at least one bypass opening is lined by a radiopaque material. 
     In Example 24, the introducer sheath of Example 16 further includes wherein the at least one plug includes a central opening for sealingly engaging with a catheter positioned within the introducer sheath. 
     In Example 25, the introducer sheath of Example 24 further includes wherein the central opening is composed of a plurality of slits. 
     In Example 26, a percutaneous device delivery system for delivering a percutaneous device includes a percutaneous device having an impeller housing for supporting an impeller and a motor configured to rotatably drive the impeller. The system further includes an introducer sheath for receiving the percutaneous device, the introducer sheath having a proximal portion, a distal portion, and a body portion extending between the proximal portion and the distal portion, the body portion defining a lumen, wherein the proximal portion comprises at least one bypass opening extending from an exterior of the introducer sheath to the lumen of the introducer sheath, and wherein the introducer sheath further includes a plug positioned within the lumen and proximally relative to the at least one bypass opening of the introducer sheath to inhibit the flow of blood into the lumen proximal of the plug. 
     In Example 27, the system of Example 26 further includes wherein the at least one bypass opening is lined with a radiopaque material. 
     In Example 28, the system of Example 26 further includes wherein the plug is composed of a radiopaque material. 
     In Example 29, the system of Example 26 further includes wherein the at least one bypass opening includes a plurality of bypass openings. 
     In Example 30, the system of Example 26 further includes wherein the at least one bypass opening includes a plurality of bypass openings. 
     In Example 31, the system of Example 26 further includes wherein the plug includes a central opening configured for receiving a catheter positioned within the introducer sheath. 
     In Example 32, the system of Example 26 further includes wherein the plug includes a central opening composed of a slit. 
     In Example 33 a method for delivering a percutaneous device into a patient includes inserting an introducer sheath into a vessel of the patient, the introducer sheath including a proximal portion opposite a distal portion, a body portion extending between the proximal portion and the distal portion and the body portion defining a lumen, and at least one bypass opening arranged at the proximal portion of the introducer sheath. The method further includes inserting the percutaneous device into the introducer sheath and advancing the device to a target position in the patient and inserting a plug into the introducer sheath arranged such that the plug is positioned adjacent to and proximally relative to the at least one bypass opening to inhibit the flow of blood into the lumen proximal of the plug. 
     In Example 34, the method of Example 33 further includes wherein the method further includes removing the plug from the introducer sheath and removing the percutaneous circulatory support device through the introducer sheath. 
     In Example 35, the method of Example 33 further includes wherein the at least one bypass opening includes a plurality of bypass openings and the plug is positioned proximally of a proximal-most bypass opening of the plurality of bypass openings. 
     While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    illustrates a side view of an introducer sheath after insertion into a blood vessel, in accordance with embodiments of the present disclosure. 
         FIG.  2    illustrates a side cross-sectional view of the introducer sheath of  FIG.  1    after insertion into the blood vessel, in accordance with embodiments of the present disclosure. 
         FIG.  3    illustrates an additional side cross-sectional view of a variation of the introducer sheath of  FIG.  1    after insertion into the blood vessel, in accordance with embodiments of the present disclosure. 
         FIG.  4 A  illustrates a top cross sectional view of an embodiment of a plug for the introducer sheath of  FIG.  1   , in accordance with embodiments of the present disclosure. 
         FIG.  4 B  illustrates a top cross sectional view of a variation of the plug for the introducer sheath of  FIG.  4 A , in accordance with embodiments of the present disclosure. 
         FIG.  5    illustrates a sectional side cutaway figure showing the introducer sheath of  FIG.  1    after receiving a percutaneous circulatory support device and insertion into the blood vessel. 
         FIG.  6    illustrates a method for deploying a delivery device through the introducer sheath of  FIG.  1   , in accordance with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the above described features. 
       FIG.  1    illustrates a side cross sectional view of a blood vessel V with an introducer sheath  100 , also referred to herein as the bypass sheath  100 , inserted at least partially into the blood vessel V. The introducer sheath  100  comprises an outer portion  102  that is positioned outside of the blood vessel V and an inner portion  104  that is positioned within the blood vessel V, or circumferentially enveloped by the blood vessel V. Specifically, with reference to the inner portion  104  of the introducer sheath  100 , the inner portion  104  comprises a proximal portion  106  and a distal portion  108  that is opposite the proximal portion  106 . The introducer sheath  100  includes a proximal opening  107  adjacent the proximal portion  106  and a distal opening  109  adjacent the distal portion  108 . A body portion  110  of the introducer sheath  100  extends between the proximal portion  106  and the distal portion  108 , and the body portion  110  defines a lumen  112  of the introducer sheath  100 . The introducer sheath  100  may be formed by various polymeric or metallic materials. In further embodiments, the introducer sheath  100  may comprise an additional surface coating. The surface coating may include, but is not limited to, silicone, PET, or any other applicable polymer. A hub  60  ( FIG.  5   ) is commonly included at the proximal opening  107 . The hub  60  may contain a valve (not shown) for hemostasis, i.e, to prevent blood from leaking out of the introducer sheath during use. 
     In the illustrative embodiment of  FIG.  1   , the lumen  112  is cylindrical in shape, however various other configurations may be incorporated. Additionally, the body portion  110  of the introducer sheath  100  comprises an inner diameter D 1   i  defining the lumen  112  and an outer diameter D 1   o . The blood vessel V is defined by an inner diameter D 2   i  and an outer diameter D 2   o . In embodiments, the outer diameter D 1   o  is slightly less than the inner diameter D 2   i  of the blood vessel V. For example, the outer diameter D 1   o  may be 95% of the value of the inner diameter D 2   i  of the blood vessel V. In various other embodiments, the outer diameter D 1   o  may be between 96% and 99% of the inner diameter D 2   i  of the blood vessel V. The inner diameter D 1   i  and outer diameter D 1   o  of the introducer sheath  100  and lumen  112  may be configured this way to allow for a device to pass through the introducer sheath  100 , as will be described further with reference to  FIGS.  5 - 6   . In this way, any spacing between the outer diameter D 1   o  of the introducer sheath  100  and the inner diameter D 2   i  of the blood vessel V is reduced. As such, any blood flow between the introducer sheath  100  and the blood vessel V is minimized or potentially essentially blocked. This may cause various complications to a patient, as the blood is not able to properly flow to the rest of the body. In order to allow for continued blood flow, at least one bypass opening may be provided within the introducer sheath  100 , as will be described further herein. 
     With continued reference to the introducer sheath  100  of  FIG.  1   , the proximal portion  106  includes at least one bypass opening  114  extending through the body portion  110 . In other words, the at least one bypass opening  114  extends from an exterior of the body portion  110  through to the lumen  112  of the introducer sheath  100 . In the illustrative embodiment of the  FIG.  2   , the introducer sheath  100  comprises a plurality of bypass openings and more specifically, a first bypass opening  114   a , a second bypass opening  114   b , and a third bypass opening  114   c . The first bypass opening  114   a  is a proximal-most bypass opening of the proximal portion  106  and the third bypass opening  114   c  is a distal-most bypass opening of the proximal portion  106 . While illustrated as three bypass openings, the plurality of bypass openings may include any number of bypass openings. For example, the plurality of bypass openings may include four, five, six or more bypass openings. Additionally, the distribution and the positioning of the plurality of bypass openings may vary from the example presented herein. For example, the plurality of bypass openings may be positioned aligned with one another in a horizontal or a vertical direction. The plurality of bypass openings may be clustered with one another and/or the plurality of bypass openings may be positioned randomly along the body portion  110 . Further, the plurality of bypass openings may be aligned such that the bypass openings  114  are aligned with anatomical features, such as branching blood vessels. The plurality of bypass openings may be varied in size, positioning, and/or shape in order to optimize blood flow through the introducer sheath  100 . 
     The configuration of the introducer sheath  100  and the bypass opening  114  allows for increased blood flow through blood vessel V as compared with traditional introducer sheaths by allowing blood to flow through the introducer sheath  100 . In traditional introducer sheaths without a bypass opening, blood that flows into the introducer sheath is substantially inhibited from flowing past the introducer sheath in a blood vessel. Thus, blood flow in the blood vessel may be essentially blocked at the location of the traditional introducer sheath. In contrast, blood flowing into the distal portion  108  of introducer sheath  100  as described herein is able to exit at the proximal portion  106  of the introducer sheath  100  due to the presence of the at least one bypass opening  114 . This allows the blood entering at the distal portion  108  to flow through the introducer sheath  100  and back into blood vessel V via the bypass opening  114 , thereby reducing the potential of the blood flow ceasing in the introducer sheath  100 . Such an arrangement also contributes to continued blood flow through the vessel V past introducer sheath  100 , which may be particularly advantageous when the outer diameter D 1   o  of the introducer sheath  100  is slightly less than the inner diameter D 2   i  of the blood vessel V. As previously described, in these instances, there is a very small space, or no space, for blood to flow between the introducer sheath  100  and the blood vessel V. 
     In some embodiments, it is advantageous to incorporate a plug within the introducer sheath  100  in order to reduce the potential for the accumulation of stagnant blood within the introducer sheath  100  in a portion that is proximal to the at least one bypass opening. Specifically, as will be described further with reference to  FIGS.  4  and  5   , the plug may be used after a percutaneous circulatory support device is delivered through the introducer sheath  100 . For example,  FIG.  3    illustrates the introducer sheath  100  of  FIG.  1    with the addition of at least one plug within the introducer sheath  100 . Specifically, the introducer sheath  100  includes a plug  120 . The plug  120  is illustrated positioned just proximally of the plurality of bypass openings, and is positioned adjacent the proximal-most bypass opening  114   a  of the introducer sheath  100 . In this way, the blood may proximally flow through the introducer sheath  100 , first entering the distal portion  108  of the introducer sheath  100  and then out of the sheath  100  through the plurality of bypass openings  114   a - c  at the proximal portion  106 . Because the plug  120  is positioned proximal to the plurality of bypass openings  114   a - c , the blood is prevented or inhibited from flowing within introducer sheath  100  into a portion of the lumen  112  of the introducer sheath  100  that is proximal to the plurality of bypass openings  114  the blood would be unable to exit the introducer sheath  100 . Thus, accumulation of blood in the introducer sheath  100  proximally of the plurality of bypass openings  114   a - c  is substantially reduced. 
     The plug  120  may have a cylindrical shape with one or more bypass openings to accommodate a catheter  170  ( FIG.  5   ) or various other tools that are inserted into the introducer sheath  100 . In these embodiments, the plug  120  may form a fluid tight seal between the plug  120  and the catheter  170  and/or tools, and the plug  120  and the introducer sheath  100  to ensure blood flow is prohibited. For example, an opening in the center of plug  120  may accommodate the catheter  170  ( FIG.  5   ) of percutaneous circulatory support device  130 , as shown in  FIGS.  4 A- 5   . The opening of the plug  120  may take a variety of forms, including a slotted opening, cross slits, or any other configuration that allows the plug  120  to be coupled to the catheter  170  without accessing the ends of the catheter  170 . For example,  FIG.  4 A  illustrates the plug  120  having a circular shape with a circular opening  121  within the center of the plug  120 . In use, the circular opening  121  is sized to sealingly engage with the catheter  170  once placed over the catheter  170 .  FIG.  4 B  illustrates a variation of the plug, illustratively the plug  120 ′, which has an overall circular shape and cross slits  121 ′ within the center of the plug  120 ′ that allow for the plug  120 ′ to be placed over the catheter  170  and form a fluid tight seal between the catheter  170 , the plug  120 , and the introducer sheath  100 . However, various other configurations of the opening of the plugs  120 ,  120 ′ may be incorporated and the illustrative embodiments herein are only presented as examples. 
     Further, it may be beneficial for the physician to have markers along the introducer sheath  100  for indicating the positioning of the introducer sheath  100  and the plurality of bypass openings  114   a - c . For example, with reference to  FIG.  2   , the plurality of bypass openings  114   a - c  may each have an outer lining (or a circumferential lining)  116  that is composed of radiopaque material. This provides the additional advantage to the physician of being able to detect the positioning of the plurality of bypass openings  114   a - c , and thus the inner portion  104  of the introducer sheath  100 , when it is placed within the blood vessel V of the patient. In further embodiments, the plug  120  may be composed of a material including, but not limited to, silicone. In these embodiments, the plug  120  may have a radiopaque coating such that the physician is able to detect the positioning of the plug  120  within the inner portion  104 . In other embodiments, the plug  120  may be formed entirely of a radiopaque material. The positioning of either the plurality of bypass openings  114   a - c  or the plug  120  may thus be detected through the use of imaging tests, such as an ultrasound, X-ray, and/or angiogram. For example, the radiopaque material may be selected such that the plurality of bypass openings  114   a - 114   c  may be identified through the use of these various tests. This allows the physician to ensure that the plurality of bypass openings  114   a - c  are in the desired position and orientation, and that the plug  120  is positioned proximally to the plurality of bypass openings  114   a - c . 
     As previously described, the introducer sheath  100  of  FIGS.  1  and  2    are used for delivery of a medical device, for example a percutaneous circulatory support device, as will be described further with reference to  FIG.  5   . While described with reference to the percutaneous circulatory support device of  FIG.  5   , the introducer sheath  100  may be used with any variation of a medical device, and the following description is provided as an example. 
       FIG.  5    illustrates an example of the introducer sheath  100  in use with a percutaneous circulatory support device  130 , also referred to herein as a blood pump  130 . Specifically,  FIG.  5    illustrates the introducer sheath  100  just after the blood pump  130  has exited the distal portion  108  of the introducer sheath  100  and is located in the blood vessel V. The blood pump  130  is thus positioned distally relative to the introducer sheath  100  and the introducer sheath  100  maintains positioning within the blood vessel V. The blood pump  130  generally includes an impeller assembly housing  140  and a motor housing  142 . In some embodiments, the impeller assembly housing  140  and the motor housing  142  may be integrally or monolithically constructed. In other embodiments, the impeller assembly housing  140  and the motor housing  142  may be separate components configured to be removably or permanently coupled. 
     The impeller assembly housing  140  carries an impeller assembly  144  therein. The impeller assembly  144  includes an impeller  148  that rotates relative to the impeller assembly housing  140  to drive blood through the blood pump  130 . More specifically, the impeller  148  causes blood to flow from a blood inlet  150  formed on the impeller assembly housing  140 , through the impeller assembly housing  140 , and out of a blood outlet  152  formed on the impeller assembly housing  140 . The inlet  150  may be formed on an end portion of the impeller assembly housing  140  and the outlet  152  may be formed on a side portion of the impeller assembly housing  140 . In other embodiments, the inlet  150  and/or the outlet  152  may be formed on other portions of the impeller assembly housing  140 . In some embodiments, the impeller assembly housing  140  may couple to a distally extending cannula (not shown), and the cannula may receive and deliver blood to the inlet  150 . 
     With continued reference to  FIG.  5   , the motor housing  142  carries a motor  154 , and the motor  154  is configured to rotatably drive the impeller  148  relative to the impeller assembly housing  140 . In the illustrated embodiment, the motor  154  rotates a drive shaft  156 , which is coupled to a driving magnet  158 . Rotation of the driving magnet  158  causes rotation of a driven magnet  160 , which is connected to the impeller assembly housing  140 . In other embodiments, the motor  154  may couple to the impeller assembly housing  140  via other components. 
     As shown in  FIG.  5   , the catheter  170  extends from the proximal portion of motor housing  142 . The catheter  170  typically contains tools such as control wires and in some examples, a guidewire, for delivering medical devices to the target location and allowing for operation of the medical devices. The tools may also be used for removing the percutaneous circulatory support device  130  from the patient. The catheter  170  extends through introducer sheath  100 , optionally through plug  120 , and outside the patient&#39;s body.  FIG.  5    illustrates that blood may flow through introducer sheath  100  due to the plurality of openings  114   a - c , as the blood can pass through the percutaneous circulatory support device  130  and into the distal portion  108  of the introducer sheath  100  and out the plurality of bypass openings  114   a - c.    
       FIG.  6    illustrates a flow chart disclosing a method  200  of using the introducer sheath  100  as illustrated in  FIGS.  1 - 3  and  5    in combination with the plug  120  as disclosed with reference to  FIGS.  3 - 4 B . At block  202 , the method  200  includes inserting the introducer sheath  100  into the blood vessel V of the patient. This may include inserting the introducer sheath  100  into an incision site of the patient such that at least inner portion  104  extends within the blood vessel V. At block  204 , the method  200  further includes inserting the percutaneous circulatory support device  130  into the introducer sheath  100 . In various embodiments, this includes first introducing the plug  120  into a starter tube, inserting the starter tube into the introducer sheath  100  and then deploying the plug  120  into the introducer sheath  100 . 
     At block  206 , the method  200  further includes inserting the plug  120  into the introducer sheath  100 . This step may further comprise inserting the plug  120  such that the plug  120  is flush with an inner surface of the lumen  112  of the introducer sheath  100  and an outer surface of a catheter or starter tube such that blood is unable to pass by or through the plug  120 . The plug  120  may be positioned proximally to the proximalmost bypass opening  114   a  of the introducer sheath  100  such that blood flow through each of the plurality of bypass openings  114  is not impeded. 
     In various embodiments, the method  200  further includes removing the plug  120  from the introducer sheath  100  such that the plug  120  may then be removed from the introducer sheath  100 , as well. As previously disclosed, while the introducer sheath  100  is described with reference to use with plug  120 , any variety of medical devices may be delivered through the introducer sheath  100  as described herein. 
     One further advantage of the introducer sheath  100  as described herein is that it eliminates the need for a separate repositioning sheath to be incorporated into the system. That is, the introducer sheath  100  may remain in place the entire time that the percutaneous circulatory support device  130  is in the patient. Removing the introducer sheath  100  and positioning an additional sheath is not necessary which may reduce the instances of traumatic injury or stress onto the blood vessel V. 
     Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the above described features.