Dual lumen sheath for arterial access

Abstract

To provide a sheath assembly for insertion of a percutaneous pump.SOLUTION: A sheath assembly 100 includes a tubular sheath body 102 dimensioned for insertion into a blood vessel through a vessel aperture. The tubular sheath body includes a wall having a proximal end portion 106, a distal end portion 108, a longitudinal axis 110, an outer surface 112, and an inner surface defining a first lumen substantially parallel to the longitudinal axis, and a second lumen disposed within the wall between the inner surface and the outer surface and extending from the proximal end portion to the distal end portion. The first lumen is dimensioned to allow passage of a portion of the percutaneous pump, and the second lumen is dimensioned for passage of a guidewire. A stylet is removably positioned to substantially occlude the second lumen.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Patent Application No. 14 / 827,741, filed Aug. 17, 2015, which is incorporated by reference in its entirety. [Background technology]

[0002] background A blood pump, such as a percutaneous intracardiac blood pump assembly, is introduced into the heart to pump blood from the heart into the arteries. When the blood pump assembly operates in the heart, it draws blood from the left ventricle and pushes it into the aorta, or draws blood from the right ventricle and pushes it into the pulmonary artery. The blood pump assembly is introduced into the vascular system surgically or percutaneously during a cardiac procedure. In one common approach, the pump assembly is inserted into the femoral artery by a catheter insertion procedure using a peel-away introducer sheath.

[0003] A peel-away introducer sheath is inserted through the arteriotomy into the femoral artery to form an insertion path for the pump assembly. A portion of the pump assembly is then advanced into the artery through the lumen of the introducer device. Once the pump assembly is inserted, the peel-away introducer sheath can be peeled away. A replacement sheath can then be advanced over the pump assembly into the arteriotomy. Replacing the introducer sheath with the replacement sheath can prevent clot formation in the introducer sheath, prevent or reduce bleeding from the arteriotomy, and allow blood to flow through the femoral artery to the leg. However, after the introducer sheath is removed, wire access to the artery is lost. Loss of guidewire access makes it more difficult to close the vessel after the procedure or to exchange devices in the arteriotomy.

[0004] To maintain guidewire access, some physicians leave the peel-away introducer sheath in the arteriotomy for extended periods of time. The prolonged presence of the peel-away sheath in the arteriotomy may reduce retraction of the arteriotomy and therefore increase the final diameter of the arteriotomy. This increase in diameter may increase the risk of bleeding from the arteriotomy after the peel-away introducer sheath is eventually removed. Additionally, the prolonged presence of the peel-away sheath in the artery may reduce perfusion through the femoral artery, thereby increasing the risk of ischemia.

[0005] In addition, clinicians may choose to monitor the patient's arterial pressure during the catheterization procedure, which often requires the placement of an additional catheter, which adds volume to the surgical site and requires insertion into the arterial system through another access point. Summary of the Invention

[0006] overview Systems, methods, and devices for an improved dual lumen repositioning sheath are presented. The dual lumen sheath can be inserted into the arteriotomy to maintain guidewire access to the arteriotomy after the introducer sheath is removed. The dual lumen sheath includes a first lumen sized for passage of a portion of the percutaneous pump and a second lumen sized for insertion of a guidewire. The second lumen receives a guidewire that is inserted into the arteriotomy along with the percutaneous pump to maintain guidewire access to the insertion path of the percutaneous pump. By maintaining guidewire access using the second lumen of the dual lumen sheath, the introducer sheath can be removed from the patient without losing guidewire access. This allows the physician to remove the introducer sheath earlier during the procedure (e.g., 1 hour, 30 minutes, 10 minutes, 5 minutes, or immediately after successful insertion of the percutaneous pump), which allows the vascular opening to return to a smaller diameter than it would have if the introducer sheath had been left in the patient longer. For example, if the introducer sheath is removed before the vascular opening has permanently relaxed to the larger diameter of the introducer sheath, a back-out of 2-3 French (0.667 mm to 1 mm) can be achieved.

[0007] The dual lumen sheath also includes a removable stylet that is inserted into the second lumen to reduce the risk of clot formation in the second lumen during the medical procedure. Maintaining the patency of the second lumen is particularly useful in procedures that require longer periods of time (e.g., 6 hours or more). The removable stylet may be reversibly coupled to the dual lumen sheath during insertion of the dual lumen sheath into the arteriotomy and during the medical procedure. Before the percutaneous pump is removed, the stylet is removed from the second lumen to allow insertion of a guidewire through the second lumen. In some embodiments, the patency of the guidewire port is maintained using a drug or non-drug coating applied to the second lumen. In certain embodiments, the second lumen is flushed with a liquid at a controlled rate to maintain patency.

[0008] In some embodiments, the dual lumen sheath also includes a rotatable connection to a stabilizing structure (e.g., a suture pad). The rotatable connection allows the outlet of the second lumen at the distal end of the sheath to rotate away from the arterial wall. This can facilitate insertion of the guidewire by allowing it to be inserted in a direction other than head-on against the arterial wall, thereby reducing friction associated with guidewire insertion. Additionally, the rotation allows the port for the second lumen to lie flat against the patient when the second lumen is not in use.

[0009] The second lumen offers numerous other possible advantages. For example, it allows arterial pressure to be transduced without the need for an additional catheter. Transducing pressure can allow the physician to determine when the dual lumen sheath has been inserted to a sufficient depth. When a second lumen is used to transduce pressure, rotation of the guidewire outlet, enabled by a rotatable connection to the stabilizing structure, can improve the reliability of the pressure measurement by keeping the outlet of the second lumen away from the arterial wall. In addition, the second lumen can also be used to determine the depth of insertion without a pressure transducer. For example, the depth of insertion can be determined by observing the onset of blood flow through the second lumen ("bleedback"), which indicates penetration into the arteriotomy. Regardless of whether a pressure transducer or a bleed back indicator is used, depth markings can be placed on the exterior surface of the sheath to facilitate measurement of the depth of insertion. The depth markings can be radiopaque. Measurement of the depth of the arteriotomy relative to the patient's skin can facilitate subsequent use of certain vascular closure devices that may require such measurements.

[0010] In one aspect, a sheath assembly for insertion of a percutaneous pump includes a tubular sheath body dimensioned for insertion into a blood vessel through a vascular opening. The tubular sheath body includes a wall having a proximal end portion, a distal end portion, a longitudinal axis, an outer surface, an inner surface defining a first lumen substantially parallel to the longitudinal axis, and a second lumen disposed within the wall between the inner surface and the outer surface and extending from the proximal end portion to the distal end portion. The first lumen is dimensioned to permit passage of a portion of the percutaneous pump, and the second lumen is dimensioned for passage of a guidewire. A stylet is removably positioned to substantially occlude the second lumen.

[0011] In certain embodiments, the stylet has a proximal end configured to be releasably secured to the sheath assembly. In some embodiments, the length of the stylet is substantially equal to the length of the second lumen. In certain embodiments, the stylet is radiopaque or includes a radiopaque marker band to indicate the distance of the sheath in the vessel. In certain embodiments, the sheath assembly also includes a hub coupled to the proximal end portion of the sheath body, the hub including a first port in fluid communication with the first lumen and a second port in fluid communication with the second lumen, the second port configured to secure the proximal end of the stylet. The sheath body may be sized to be introduced through a percutaneous access site of about 20 Fr (6.67 mm) or less (e.g., 19 Fr, 18 Fr, 17 Fr, 16 Fr, 15 Fr, 14 Fr, 13 Fr, 12 Fr, 10 Fr, 9 Fr, 8 Fr, 6 Fr, or less).

[0012] In some embodiments, the distal end portion of the sheath body is tapered and includes a tapered surface extending to a distal end surface, the distal end surface being substantially perpendicular to the longitudinal axis of the sheath body. In certain embodiments, the second lumen has an outlet extending through the tapered surface of the distal end portion of the sheath body. The second lumen may be coated with an anti-thrombotic agent. In some embodiments, the outer surface of the wall of the tubular sheath body includes a hydrophilic coating or any other suitable coating to prevent tissue adhesion. In some embodiments, the outer surface of the wall of the tubular sheath body includes a hydrophilic coating or any other suitable coating to reduce frictional forces during insertion / removal of the sheath into the vasculature. In some embodiments, the outer surface of the wall of the tubular sheath body includes an antimicrobial coating or any other suitable coating to prevent or reduce infection risk. Additionally, in some embodiments, the inner surfaces of the two lumens include an antimicrobial coating or any other suitable coating to prevent or reduce infection risk. In certain embodiments, the outer surface of the wall includes markings for determining the depth of insertion, e.g., marks evenly spaced on the outer surface of the wall.

[0013] In certain embodiments, the claimed sheath assembly also includes a stabilization structure rotatably coupled to the tubular sheath body. The stabilization structure may be rotatable about a longitudinal axis. In some embodiments, the stabilization structure includes features configured for suturing to a patient. The stabilization structure may include a pair of suture wings, each wing having a plurality of ribs for securing a suture.

[0014] In another aspect, a method for maintaining guidewire access includes inserting a sheath having a first lumen and a second lumen into a blood vessel through a percutaneous insertion pathway and along a portion of a percutaneous pump, maintaining the sheath in the blood vessel for more than six hours while preventing clot formation from blocking the second lumen, and after more than six hours, inserting a guidewire through the second lumen into the percutaneous insertion pathway.

[0015] In some embodiments, maintaining patency includes inserting a stylet into the second lumen for more than 6 hours and removing the stylet before inserting the guidewire. In certain embodiments, maintaining patency includes flushing the second lumen with a purging fluid. In some embodiments, the method also includes removing the sheath while maintaining the guidewire in the percutaneous insertion path. In certain embodiments, the method also includes inserting a percutaneous device into the percutaneous insertion path along the guidewire after removing the sheath. In some embodiments, the method also includes coupling a sensor to a proximal inlet of the second lumen and using the sensor to transduce arterial pressure at a distal outlet of the second lumen. In certain embodiments, the method also includes rotating the sheath relative to the support structure when the pressure measurements indicate that the distal outlet is blocked by the arterial wall. In some embodiments, the method also includes determining a depth of insertion from the pressure measurements. The depth of insertion can be determined using depth markers disposed on an outer surface of the sheath.

[0016] Variations and modifications will occur to those skilled in the art after considering this disclosure. The disclosed features may be realized in any combination and subcombination (including multiple subcombinations and subcombinations) with one or more other features described herein. The various features may be combined or integrated into other systems, including any of their constituent parts. Moreover, certain features may be omitted or not realized. [The present invention 1001] 1. A sheath assembly for insertion of a percutaneous pump, comprising: a tubular sheath body sized for insertion into a blood vessel through a blood vessel opening, the tubular sheath body comprising: a wall having a proximal end portion, a distal end portion, a longitudinal axis, an outer surface, and an inner surface defining a first lumen substantially parallel to the longitudinal axis, the first lumen being dimensioned to permit passage of a portion of the percutaneous pump; a second lumen disposed within the wall between the inner surface and the outer surface and extending from the proximal end portion to the distal end portion, the second lumen being dimensioned for passage of a guidewire; and a stylet having a proximal end releasably secured to the sheath assembly positioned to substantially occlude the second lumen; 4. A sheath assembly comprising: [The present invention 1002] A sheath assembly of the present invention 1001, wherein the length of the stylet is substantially equal to the length of the second lumen. [The present invention 1003] The sheath assembly of the present invention 1001, wherein the second lumen has a proximal section having a proximal section diameter and a distal section having a distal section diameter, the proximal section diameter being larger than the distal section diameter. [The present invention 1004] A sheath assembly of the present invention 1003, wherein the distal section diameter is approximately equal to the outer diameter of the stylet. [The present invention 1005] A sheath assembly of the present invention 1001, wherein the second lumen is coated with an anti-thrombotic agent. [The present invention 1006] The sheath body further includes a hub coupled to a proximal end portion of the sheath body, the hub comprising: a first port in fluid communication with the first lumen; and a second port in fluid communication with the second lumen wherein the second port is configured to secure a proximal end of a stylet. [The present invention 1007] The sheath assembly of the present invention 1001, wherein the outer surface of the wall includes at least one of a hydrophilic coating and a coating for reducing tissue adhesion. [The present invention 1008] A sheath assembly of the present invention 1001, wherein the exterior surface of the wall includes markings for determining insertion depth. [The present invention 1009] The sheath assembly of the present invention 1001, wherein a distal end portion of the sheath body is tapered and includes a tapered surface extending to a distal end surface, the distal end surface being substantially perpendicular to a longitudinal axis of the sheath body. [The present invention 1010] The sheath assembly of the present invention 1009, wherein the second lumen has an exit extending through a tapered surface of the distal end portion of the sheath body. [The present invention 1011] The sheath assembly of the present invention 1001 further comprising a stabilization structure rotatably coupled to the tubular sheath body. [The present invention 1012] A sheath assembly of the present invention 1011, wherein the stabilization structure is rotatable about the longitudinal axis. [The present invention 1013] A sheath assembly of the present invention 1012, wherein the stabilization structure includes features configured for suturing to a patient. [The present invention 1014] A sheath assembly according to the present invention 1013, wherein the stabilization structure includes a pair of suture wings, each wing having a plurality of ribs for securing a suture. [The present invention 1015] A sheath assembly of the present invention 1001, wherein the sheath body is dimensioned to be introduced through a percutaneous access site of about 20 Fr (6.67 mm) or less. [The present invention 1016] 1. A method for maintaining guidewire access, comprising: inserting a sheath having a first lumen and a second lumen into the blood vessel through the percutaneous insertion pathway and along a portion of the percutaneous pump; maintaining the sheath in the blood vessel for more than six hours while preventing clot formation from blocking the second lumen; and after more than six hours, inserting a guidewire through the second lumen into the percutaneous insertion pathway. The method includes: [The present invention 1017] The method of claim 1016, wherein maintaining patency comprises inserting a stylet into the second lumen for more than six hours and removing the stylet prior to inserting the guidewire. [The present invention 1018] The method of claim 1016, wherein maintaining patency comprises flushing the second lumen with a purging fluid. [The present invention 1019] The method of claim 1016, further comprising the step of removing the sheath while maintaining the guidewire in the percutaneous insertion path. [The present invention 1020] The method of claim 1019, further comprising the step of inserting a percutaneous device along the guidewire into the percutaneous insertion pathway after removing the sheath. [The present invention 1021] coupling a sensor to a proximal inlet of the second lumen; and Transducing arterial pressure at a distal outlet of the second lumen using the sensor. The method of the present invention 1019 further comprises: [The present invention 1022] The method of claim 1021, further comprising the step of rotating the sheath relative to the support structure when the pressure measurements indicate that the distal outlet is blocked by the arterial wall. [The present invention 1023] The method of claim 1022 further comprising determining the depth of insertion from the pressure measurements. [The present invention 1024] The method of claim 1023, wherein the depth of insertion is determined based on marks placed on the outer surface of the sheath.

[0017] The above and other objects and advantages will become apparent from the following detailed description considered in conjunction with the accompanying drawings, in which like reference numerals refer to like parts throughout. [Brief description of the drawings]

[0018] [Figure 1] 1 illustrates a top view of an exemplary dual lumen sheath for arterial access. [Diagram 2]2 shows a side cross-sectional view of the dual lumen sheath of FIG. 1. [Diagram 3] 2 shows a cross-sectional view of a distal portion of the dual lumen sheath of FIG. 1. [Figure 4] 2 shows a detailed cross-sectional view of a distal portion of the dual lumen sheath of FIG. 1. [Diagram 5] 2 illustrates the dual lumen sheath of FIG. 1 inserted into a patient's blood vessel along with a percutaneous pump. [Figure 6] 1 illustrates an exemplary process for maintaining guidewire access. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Detailed Description Certain exemplary embodiments are described to provide an overall understanding of the systems, methods, and devices described herein. Although the embodiments and features described herein are specifically described with respect to use in connection with a percutaneous blood pump system, it will be understood that all components and other features outlined below may be combined with one another in any suitable manner and adapted and applied to other types of cardiac therapy and cardiac assist devices, including balloon pumps, cardiac assist devices implanted using surgical incisions, and the like.

[0020] The systems, methods and devices described herein provide a dual lumen sheath having a first lumen sized for passage of a portion of a percutaneous pump and a second lumen sized for insertion of a guidewire. The second lumen is positioned to allow a guidewire to be inserted into the insertion path of the percutaneous pump. This allows guidewire access to the insertion path to be maintained even after the percutaneous pump and the dual lumen sheath are withdrawn. The guidewire access allows one or more other instruments (e.g., a vascular closure instrument) to be inserted into the same insertion path at a later time to facilitate vascular closure or any other medical procedure involving guidewire access. The second lumen allows the physician to maintain guidewire access even after the introducer sheath is removed, allowing the physician to remove the introducer sheath earlier during the medical procedure. Early removal of the introducer sheath allows the insertion path to return to a smaller diameter, thereby reducing the risk of bleeding from the access site.

[0021] The systems, methods and devices described herein also include a stylet that maintains the patency of the second lumen. The stylet is used to occlude the second lumen when the second lumen is not being used for guidewire insertion or pressure measurement. For example, a removable stylet can be positioned in the second lumen during insertion of the dual lumen sheath into the arteriotomy and during operation of the percutaneous pump. Before the percutaneous pump is removed, the stylet is removed from the second lumen to allow for insertion of a guidewire through the second lumen. Occlusion of the second lumen by the stylet can prevent blood clot formation in the second lumen during medical procedures that require an extended period of time (e.g., 6 hours or more). This allows the second lumen to remain accessible during and after the medical procedure, for example, to provide a path for insertion of a guidewire before removing the percutaneous pump. In some embodiments, blood clot formation is prevented using a drug or non-drug coating applied to the second lumen. In certain embodiments, clot formation is prevented by flushing the second lumen with a liquid at a controlled rate.

[0022] The dual lumen sheath may also include a rotatable connection to a stabilizing structure (e.g., suture wings). The rotatable connection allows the outlet of the second lumen at the distal end of the sheath to rotate away from the arterial wall. This can facilitate insertion of the guidewire by allowing the guidewire to be inserted in a direction other than head-on against the arterial wall, thereby reducing friction associated with guidewire insertion. Additionally, the rotation allows the port for the second lumen to lie substantially flat against the patient when the second lumen is not in use.

[0023] The second lumen can also establish fluid communication between the guidewire port and the interior of the blood vessel. This can allow for arterial pressure measurement (e.g., by a pressure transducer) during the procedure without the use of a separate catheter. Measuring arterial pressure can allow the physician to detect when the dual lumen sheath has been inserted sufficiently deep into the blood vessel. Rotation of the guidewire outlet, enabled by the rotatable connection to the stabilizing structure, can improve the reliability of the pressure measurement by keeping the outlet of the second lumen away from the arterial wall.

[0024] FIG. 1 illustrates an exemplary dual lumen sheath assembly 100 for maintaining arterial access in accordance with certain embodiments. FIG. 2 illustrates a side cross-sectional view of the sheath assembly 100 taken along section line 2-2, and FIG. 3 illustrates a cross-sectional view of a distal portion of the sheath assembly 100 taken along section line 3-3. The sheath assembly 100 includes a tubular sheath body 102, a stylet 120, a hub 126, and a stabilizing structure 150. The tubular sheath body 102 is sized for insertion into a blood vessel through a vascular opening. In some embodiments, the tubular sheath body 102 is sized for insertion into a femoral artery through an arteriotomy. A majority of the tubular sheath body 102 may have a substantially uniform outer diameter 101 of approximately 10 Fr, 11 Fr, 12 Fr, 13 Fr, 14 Fr, 15 Fr, 16 Fr, 17 Fr, 20 Fr, or any other suitable diameter. The tubular sheath body may be sized to be introduced through a percutaneous access site of about 20 Fr (6.67 mm) or less (e.g., 19 Fr, 18 Fr, 17 Fr, 16 Fr, 15 Fr, 14 Fr, 13 Fr, 12 Fr, 10 Fr, 9 Fr, 8 Fr, 6 Fr, or less). The tubular sheath body may have a length of about 80 mm, 100 mm, 120 mm, 140 mm, 160 mm, or any other suitable length. In addition, the tubular sheath body 102 may be manufactured from a flexible material, such as polyether block amides or any other suitable polymer, to reduce stress on the vascular opening.

[0025] The tubular sheath body 102 includes a wall 104, a proximal end portion 106, a distal end portion 108, a longitudinal axis 110, an outer surface 112, a first inner surface 114, a second inner surface 115, a first lumen 116, and a second lumen 118. The distal end portion 108 of the tubular sheath body 102 includes a tapered surface 103, a first outlet 105 in fluid communication with the first lumen 116, and a second outlet 107 in fluid communication with the second lumen 118. The tapered surface 103 has an outer diameter that graduates from 11 Fr to 15 Fr (3.667 mm to 5 mm). The gradation of the tapered surface 103 may allow the sheath to be inserted to variable depths as needed to bridge a gap between the percutaneous pump and the insertion site.

[0026] The outer surface 112 of the tubular sheath body 102 may be coated with a hydrophilic coating to facilitate insertion of the tubular sheath body 102 into the arteriotomy. The hydrophilic coating may also prevent adhesion to the vessel wall. Such adhesion may damage the vessel if the sheath is left in the vessel for an extended period of time (e.g., days) and then removed. As the duration of the procedure increases, the risk of adhesion to the vessel wall may increase. In some embodiments, the outer surface 112 of the tubular sheath body 102 includes depth markings. The depth markings may be pad printed or laser etched onto the outer surface 112. In certain embodiments, the depth markings are radiopaque. The depth markings may be in centimeters, inches, millimeters, or any other suitable units of measurement or combinations thereof.

[0027] The first inner surface 114 of the tubular sheath body defines a first lumen 116. The first lumen 116 is dimensioned to allow passage of a portion of a percutaneous pump. The first lumen 116 extends substantially parallel to the longitudinal axis 110 from the proximal end portion 106 to the distal end portion 108 of the tubular sheath body 102. The second lumen 118 is disposed within the wall 104 between the inner surface 114 and the outer surface 112. The second lumen 118 extends from the proximal end portion 106 to the distal end portion 108 of the tubular sheath body 102 at a position offset from and substantially parallel to the longitudinal axis 110. The second lumen 118 is dimensioned for passage of a guidewire and is defined by a second inner surface 115 (as shown in FIG. 3 ). The second inner surface 115 may include a drug or non-drug coating to prevent clot formation in the second lumen 118. In some embodiments, the second inner surface is coated with heparin. The second lumen 118 terminates in a second outlet 102 formed in the tapered surface 103. The second outlet 102 is adjacent to the first outlet 105 of the first lumen 116. As a result, when a guidewire is inserted through the second lumen 118, the guidewire passes through the first lumen 116 and enters the insertion path of the percutaneous pump (not shown). Thus, the second lumen 118 can be used to maintain or restore guidewire access to the insertion path of the percutaneous pump inserted through the first lumen 116. This allows guidewire access to the insertion path to be maintained even after the introducer sheath is removed. The guidewire access allows one or more other instruments to be inserted later into the same insertion path to facilitate vascular closure or any other medical procedure involving guidewire access. For example, guidewire access may allow for subsequent insertion of a vascular closure device or a pressure measuring microcatheter (e.g., a MILLAR Mikro-Tip® pressure catheter). The pressure measuring microcatheter may allow for measurement of left ventricular pressure or any other suitable pressure.Furthermore, the second lumen allows the physician to maintain guidewire access even after the introducer sheath is removed, allowing the physician to remove the introducer sheath earlier. Early removal of the introducer sheath allows the vessel opening to return to a smaller diameter, thereby reducing the risk of bleeding from the access site. Additionally, because the second outlet 107 is located off the longitudinal axis 110, rotation of the tubular sheath body 102 allows the position of the second outlet 107 to be adjusted. This can allow the user to maintain the second outlet 107 away from the vessel wall to facilitate guidewire insertion or to increase the accuracy of arterial pressure measurements.

[0028] The tubular sheath body 102 has its proximal end portion 106 connected to a hub 126. The hub 126 includes a first port 128, a second port 130, a second port thread 131, and a bearing 136. The second port 130 is connected to the second lumen 118 such that a guidewire can be inserted through the second port 130 into the second lumen 118 and out the second outlet 107. When a guidewire is not in the second lumen 118, a stylet 120 can be inserted into the second port 130 to seal the second lumen 118 (as shown in FIGS. 1, 2, and 3). The stylet 120 includes a head 121, a stylet body 122, a rounded end 123, and threads 126. The stylet body 122 is sized to substantially occlude the second lumen 118 when the stylet 120 is inserted into the second lumen 118. In some embodiments, the stylet body 122 is made of a moldable or ductile material, such as a metal. This may allow the stylet to be molded into a shape that reduces stress on the vascular opening during or before a medical procedure. In certain embodiments, the stylet 120 is radiopaque or includes a radiopaque marker band to indicate the depth of the tubular sheath body 102 in the blood vessel. The threads 124 of the stylet head 121 reversibly mate with the second port threads 131 to retain the stylet 120 within the second lumen 118. When the stylet head 121 is reversibly coupled to the second port 130, the stylet head 121 forms a fluid-tight seal across the second port 130 that prevents blood from leaking out of the blood vessel. In certain embodiments, a pressure bag is connected to the second port 130 using the threads 131 in place of the stylet 120. The pressure bag can be used to flush fluid into the second lumen 118 to maintain patency of the second lumen 118. An infusion pump can be used in conjunction with the pressure bag to regulate the flow rate of fluid to the patient. For example, the flow rate can be limited to 1 mL / hr, 2 mL / hr, 5 mL / hr, 10 mL / hr, or any other suitable rate.In some embodiments, a pressure measuring device is connected to the second port 130 to measure the pressure within the blood vessel 10. This pressure measurement can be used to determine when the second port 102 has been inserted deep enough into the blood vessel opening. For example, when a pressure approximately equal to the arterial pressure is measured at the second port 130, the second outlet 107 can be in fluid communication with the blood vessel. The pressure measurement can also be used to monitor the arterial pressure in the patient's blood vessel during the medical procedure. This can allow arterial pressure measurements to be performed without the use of an additional catheter, which can reduce the amount of equipment required at a potentially complicated surgical site.

[0029] A first port 128 in the hub 126 allows for the passage of a percutaneous pump (not shown). The first port 128 includes a cap 132 and a seal 134. The cap 132 snaps onto the first port 128 to hold the seal 134 against the first port 128. Together, the cap 132 and the seal 134 act as a hemostasis valve and form a fluid-tight seal between the percutaneous pump and the first port 128. The seal 134 is formed of an elastomer, such as silicone, so that it can flex to seal around a portion of the percutaneous pump.

[0030] The hub 126 is coupled to the stabilizing structure 150 by the bearing 136. The stabilizing structure 150 includes wings 152 and 154, suture holes 156-159, ribs 160-162, and a bearing surface 164 that mates with the bearing 136. The engagement of the bearing surface 164 of the stabilizing structure 150 with the bearing 136 of the hub 126 allows rotation of the hub 126 relative to the stabilizing structure 150. As described above, this rotation allows the tubular sheath body 102 to rotate so that the second outlet 107 faces away from the vessel wall. Additionally, this rotation allows the second port 130 to lie flat against the patient when the second port 130 is not in use. The suture holes 156-159 allow the wings 152 and 154 to be sutured to the patient to stabilize the sheath assembly 100. Although only four suture holes 156-159 are shown, any suitable number of suture holes may be used. The stabilizing structure 150 is also designed to be easily attached to the graft with umbilical tape or sutures. This feature is beneficial during axillary insertion or any other insertion that requires placing a pump through the graft. Additionally, in some embodiments, the stabilizing structure 150 is coupled to the patient using ribs 160-162. For example, sutures may be wrapped around the outer surface 165 of the stabilizing structure between the ribs 160-162. When the sutures are wrapped around the outer surface 165 in this manner, the ribs 160-162 prevent the sutures from slipping off the outer surface 165 along the longitudinal axis 110. In certain embodiments, other stabilizing devices, such as surgical tape, a STATLOCK® stabilizing device (Bard Access Systems, Inc., Salt Lake City, UT), or any other suitable adhesive stabilizing device, may be coupled to the stabilizing structure 150 around the ribs 160-162.

[0031] Figure 4 shows a detailed cross-sectional view of the distal end portion 108 of the dual lumen sheath assembly 100 of Figures 1, 2 and 3. The distal end portion 108 includes the tapered surface 103, the first outlet 105, the second outlet 107, and the distal portions of the stylet body 122, the first lumen 116 and the second lumen 118. The first lumen 116 includes a proximal section 116a having an inner diameter 117, a distal section 116b having an inner diameter 217 smaller than the inner diameter 117, and a restriction 216 therebetween. The inner diameter 117 is approximately 13 Fr (4.333 mm) and the inner diameter 217 is approximately 9 Fr (3 mm). The restriction 216 allows the distal section 116b of the first lumen 116 to form a tighter fit with the percutaneous pump to prevent or reduce blood leakage without creating unacceptably high friction in the proximal section 116a. Similar to the first lumen 116, the second lumen 118 includes a proximal section 118a having a diameter 119, a distal section 118b having a diameter 219 smaller than the diameter 119, and a restriction 218 therebetween. The diameter 119 is about 1.1 mm, and the diameter 219 is about 1 mm. The restriction 218 allows a tighter fit between the stylet body 122 and the second lumen 118 at the distal section 118a to reduce blood ingress while allowing play in the proximal section 118b to reduce friction. Friction between the second lumen 118 and the stylet body 122 is further reduced by the rounding of the end 123 of the stylet body 122. When the stylet 120 is fully inserted into the second lumen 118 , the rounded end 123 abuts the second exit port 107 , thereby preventing or reducing blood entry into the second lumen 118 .

[0032] FIG. 5 shows the dual lumen sheath assembly 100 of FIG. 1 inserted into a patient's blood vessel 10 along with a percutaneous pump 60. The percutaneous pump 60 includes a pump head 66 and a catheter body 62. The percutaneous pump 60 may be an intravascular blood pump, a blood pump driven by a flexible drive shaft, a blood pump including an implantable motor, a blood pump with an expandable pump rotor, or any other suitable pump. The dual lumen sheath assembly 100 is advanced into the blood vessel 10 along with the catheter body 62 of the percutaneous pump 60 in the direction indicated by arrow 70 through the blood vessel opening 12. When the percutaneous pump 60 is initially inserted into the blood vessel 10, the first lumen 116 of the dual lumen sheath assembly 100 may be threaded into the catheter body 62. The blood vessel 10 may be a femoral artery, and the blood vessel opening 12 may be an arteriotomy. The blood vessel opening 12 may have an opening slightly larger than the diameter 64 of the catheter body 62. Thus, the tubular body 102 of the dual lumen sheath assembly 100 can effectively fill the gap between the vascular opening 12 and the catheter 64 when the sheath assembly 100 is advanced into the blood vessel 10 along the catheter body 62. The outer diameter 101 of the tubular sheath body 102 can be gradually changed as described above such that the diameter 101 of the tubular sheath body 102 increases from its distal end portion 108 to its proximal end portion 106. This can allow the tubular sheath body 102 to be inserted deeper into the blood vessel 100 to fill a larger gap between the vascular opening 12 and the catheter body 62. The gap filling effect of the tubular sheath body 102 can reduce or prevent bleeding from the vascular opening 12. The tubular sheath body 102 is flexible such that it can form a bend 80 that allows the tubular sheath body 102 to follow the shape of the blood vessel 10. This flexibility can reduce stress on the vascular opening 12 by reducing the force required to deform the tubular sheath body 102 .

[0033] Once the tubular sheath body 102 has been advanced along the catheter body 62 of the percutaneous pump 60 to a sufficient depth to bridge the gap between the vascular opening 12 and the catheter body 62, the dual lumen sheath assembly 100 may be secured to the catheter body 62. This may be accomplished by securing the stabilizing structure 150 to the patient's tissue 14. In some embodiments, this is accomplished by suturing wings (not shown) of the stabilizing structure 150 to the patient's tissue 14. In certain embodiments, the stabilizing structure 150 is attached to the graft with an umbilical tape or sutures. This may be performed during axillary insertion or any other insertion that requires placement of the pump through the graft. In some embodiments, securing the placement of the dual lumen sheath assembly 100 may be accomplished by tightening the seal 134 around the catheter body 62 or by a separate fixation ring. The second port 130 may be rotated relative to the stabilizing structure 150 to lie flat against the patient's tissue 14. After the dual lumen sheath assembly 100 is secured in place, the physician may begin operation of the percutaneous pump 60. The percutaneous pump 60 may be operated during percutaneous coronary intervention (PCI), open heart surgery, heart valve replacement surgery, or treatment of acute myocardial infarction (AMI), cardiogenic shock, or ST-segment elevation myocardial infarction (STEMI), as well as any other suitable medical procedure. In certain embodiments, the percutaneous pump 60 is operated for an extended period of time, such as more than 6 hours, more than 12 hours, more than 24 hours, more than 48 hours, more than 72 hours, more than one week, or any other suitable period of time. In such cases, a stylet (not shown in FIG. 5), such as the stylet 120 of FIGS. 1-4, may be positioned within the second lumen 118 during insertion of the dual lumen sheath assembly 100 to prevent blood from entering the second lumen 118, which may result in clotting that may block the second lumen 118 or bleeding from the second port 130.

[0034] In certain embodiments, the second port 130 of the dual lumen sheath assembly 100 is used to deliver a contrast agent (eg, iodine or barium compounds) into the blood vessel for visualizing blood flow.

[0035] In certain embodiments, a pressure bag is connected to the second port 130 instead of the stylet to maintain patency of the second lumen 118. An infusion pump may be used in conjunction with the pressure bag to regulate the flow rate of the fluid to the patient. For example, the flow rate may be limited to 1 mL / hr, 2 mL / hr, 5 mL / hr, 10 mL / hr, or any other suitable rate. In some embodiments, a pressure measuring device is connected to the second port 130 to measure the pressure within the blood vessel 10. This pressure measurement may be used to determine when the second port 102 has been inserted sufficiently deep into the blood vessel opening 12. For example, the second outlet 107 may be in fluid communication with the blood vessel 10 when a pressure approximately equal to the arterial pressure is measured at the second port 130. After penetration of the blood vessel opening 12 is detected, the depth of the blood vessel opening 12 relative to the patient's skin may be measured using depth marks located on the exterior surface of the sheath. This depth measurement may facilitate subsequent use of certain blood vessel closure devices that may require such measurements. The pressure measurements can also be used to monitor arterial pressure in blood vessel 10 during a medical procedure. This may allow arterial pressure measurements to be performed without the use of an additional catheter, which may reduce the amount of equipment required at a potentially intricate surgical site. Additionally, second lumen 118 may allow for determination of depth of insertion without a pressure transducer by allowing observation of the onset of blood flow through second lumen 118 ("bleed back"), which indicates penetration into vascular opening 12.

[0036] When it is time to remove the percutaneous pump 60, the guidewire 50 is inserted into the second lumen 118 through the second port 130 and into the blood vessel 10 through the second outlet 107. The guidewire 50 thus enters the same insertion path as the percutaneous pump 60, thereby maintaining access to the insertion path. If a stylet was used during insertion of the dual lumen sheath assembly 100, the stylet is removed prior to insertion of the guidewire 50. The guidewire 50 has an outer diameter that approximately matches the inner diameter of the second outlet 107 to prevent blood from flowing out of the blood vessel 10 through the second port 130. For example, the guidewire may have an outer diameter of about 1 mm. Additionally, in some embodiments, a seal is included at the second port 130 to further ensure that blood does not exit the second port 130 while the guidewire 50 is in place.

[0037] After the guidewire 50 is positioned in the blood vessel 10, the percutaneous pump 60 and dual lumen assembly 100 may be removed through the blood vessel opening 12 with the guidewire 50 in place. The tubular sheath body 102 may be coated with a hydrophilic coating or any other suitable coating that prevents adhesion to the blood vessel 10, thereby facilitating removal of the tubular sheath body 102 without damaging the blood vessel 10. Removal of the dual lumen sheath assembly 100 and percutaneous pump 60 with the guidewire 50 in place allows guidewire access to the insertion path 11 to be maintained. Removal of the percutaneous pump 60 requires concurrent removal of the dual lumen sheath assembly 100, since the diameter 68 of the pump head 66 cannot pass through the first lumen 116, because the inner diameter of the first lumen 116 is sized to fit snugly around the diameter 64 of the catheter body 62 and cannot accommodate the larger diameter 68 of the pump head 66. As a result, the first lumen 116 cannot be used to maintain guidewire access to the insertion pathway 11. Therefore, the second lumen 118 is necessary to maintain guidewire access to the insertion pathway 11.

[0038] After the percutaneous pump 60 and the dual lumen sheath assembly 100 are removed, the guidewire 50 remains in the blood vessel 10 and the insertion path 11. Thus, another instrument may be inserted along the guidewire 50 into the insertion path 11. In some embodiments, the guidewire 50 is used to insert a vascular closure device into the insertion path 11. The vascular closure device may be a VASOSEAL vascular sealing device, an ANGIO-SEAL bioabsorbable active closure system, a PERCLOSE vascular sealing device, or any other suitable vascular closure device or combination of vascular closure devices. After the vascular closure device or other device has been successfully inserted into the insertion path 11 through the vascular opening 12, the guidewire 50 may be removed from the vascular opening 12.

[0039] FIG. 6 illustrates an exemplary process 600 for maintaining guidewire access. The exemplary process 600 may be performed using the dual lumen sheath assembly 100 or any other suitable sheath tool. In step 602, a sheath is inserted into a blood vessel through a percutaneous insertion path and along a portion of a percutaneous pump. The sheath has a first lumen and a second lumen. The blood vessel may be an artery, such as a femoral artery. The insertion path passes through a blood vessel opening (e.g., an arteriotomy). Prior to step 602, a percutaneous pump is inserted into the insertion path using an introducer device. Thus, the percutaneous pump guides the sheath into the existing insertion path. The percutaneous pump may be an intravascular blood pump, a blood pump driven by a flexible drive shaft, a blood pump including an implantable motor, a blood pump with an expandable pump rotor, or any other suitable pump. To prevent leakage of blood from the patient's blood vessel, the first lumen of the sheath may be sealed against the percutaneous pump by a hemostasis valve.

[0040] In some embodiments, the sheath is only inserted into the blood vessel to a depth necessary to close the gap between the percutaneous pump and the vascular opening to prevent bleeding. To reliably detect whether the sheath has been inserted deep enough into the blood vessel, the second lumen can be used to detect the pressure within the blood vessel. For example, a detected pressure approximately equal to the arterial pressure can indicate that the outlet of the second lumen has been inserted into the blood vessel. Alternatively, the second lumen can allow for the determination of the depth of insertion without a pressure transducer by allowing for the observation of the onset of blood flow through the second lumen ("bleed back"), which indicates penetration into the vascular opening. After penetration into the vascular opening is detected, the depth of the vascular opening relative to the patient's skin can be measured using depth marks placed on the outer surface of the sheath. In some embodiments, the depth marks are radiopaque and can be imaged using tomography (e.g., CT, MRI, X-ray). This depth measurement can facilitate the subsequent use of certain vascular closure instruments that may require such measurements. Additionally, once inserted to the appropriate depth, the second lumen can be used to measure the arterial pressure during the procedure.

[0041] In step 604, the sheath is maintained in the vessel for about 6 hours or more while preventing clot formation from blocking the second lumen. The sheath can be maintained in the vessel for 6 hours, 12 hours, 24 hours, 48 ​​hours, 72 hours, 1 week, 2 weeks, or any other suitable period. During this period, a stylet that temporarily blocks the second lumen can be used to prevent clot formation in the second lumen. For example, the stylet 120 of FIGS. 1-3 can be used to temporarily block the second lumen. In certain embodiments, clot formation in the second lumen is prevented or reduced by using a drug or non-drug coating in the second lumen. The coating can include heparin or any other suitable substance. In some embodiments, clot formation in the second lumen is prevented or reduced by flushing the second lumen with a liquid (e.g., saline, glucose solution, or any other suitable solution). Preventing blockage of the second lumen by clots allows the patency of the second lumen to be ensured for insertion of the guidewire.

[0042] In step 606, after about 6 hours or more, a guidewire is inserted through the second lumen into the percutaneous insertion pathway. If a stylet was used to temporarily occlude the second lumen, the stylet is removed before inserting the guidewire. The percutaneous pump inserted through the first lumen may be removed after the guidewire is inserted. After the guidewire is inserted, the sheath may be removed from the percutaneous insertion pathway while leaving the guidewire in place. This may allow another instrument (e.g., an access closure instrument) to be inserted into the insertion pathway. This frees the physician from relying on the introducer device to maintain guidewire access. Thus, the physician may remove the introducer device earlier during the procedure. This may allow for greater return of the vascular opening, thereby reducing the risk of bleeding. For example, removing the introducer device within an hour of insertion may allow for return of about 2-3 Fr (0.667 mm-1 mm).

[0043] The foregoing is merely illustrative of the principles of the present disclosure, and the systems, methods and devices may be practiced in other than the above-described manner presented for purposes of illustration and not limitation. It will be understood that while the systems, methods and devices disclosed herein are illustrated with respect to use in a percutaneous intravascular blood pump system, they may also be applied to systems, methods and devices for other implantable blood pumps or implantable cardiac assist devices.

[0044] Variations and modifications will occur to those skilled in the art after considering this disclosure. For example, in some embodiments, the sheath assembly may be used to provide guidewire access for short-term (e.g., less than 6 hours) procedures. Furthermore, the stylet may be omitted in some embodiments where the patency of the second lumen is adequately maintained by other means. For example, in some embodiments, the second lumen is flushed with liquid intermittently or continuously. The disclosed features may be realized in any combination and subcombination (including multiple subcombinations and subcombinations) with one or more other features described herein. The various features described above, including any component parts thereof, may be combined or integrated into other systems. Moreover, certain features may be omitted or not realized.

[0045] Examples of modifications, substitutions and variations are ascertainable by one skilled in the art and can be made without departing from the scope of the information disclosed herein. All references cited herein are incorporated by reference in their entirety and constitute a part of this application.

Claims

1. 1. An assembly for a percutaneous intravascular blood pump and for insertion of a guidewire, comprising: The assembly comprises: a guidewire having a proximal end and a distal end; a stylet having a proximal end and a distal end, the stylet including a stylet head at the proximal end; A tubular sheath body dimensioned for insertion into a blood vessel through a vascular opening and for receiving and delivering an intravascular blood pump, the tubular sheath body comprising: a wall having a proximal end portion, a distal end portion, a longitudinal axis, an outer surface, and an inner surface defining a first lumen parallel to the longitudinal axis, the first lumen being dimensioned to allow passage of at least a portion of the intravascular blood pump; and a second lumen disposed within the wall between the inner surface and the outer surface and extending from the proximal end portion to the distal end portion. the tubular sheath body comprising: a hub coupled to the tubular sheath body and having a port in fluid communication with the second lumen; Including, the second lumen is sized to individually receive (1) a distal end of a guidewire and (2) a distal end of a stylet; When the stylet is positioned within the second lumen, a distal end of the stylet occludes the second lumen and the stylet head of the stylet forms a fluid-tight seal across the port. assembly.

2. 10. The assembly of claim 1, wherein the stylet and the second lumen each have a length, the length of the stylet equal to the length of the second lumen.

3. 2. The assembly of claim 1, wherein the second lumen has a proximal section having a proximal section diameter and a distal section having a distal section diameter, the proximal section diameter being larger than the distal section diameter.

4. The assembly of claim 3, wherein the distal section diameter is equal to an outer diameter of the stylet.

5. 10. The assembly of claim 1, wherein the second lumen is coated with an anti-thrombotic agent.

6. the hub is coupled to a proximal end portion of the sheath body, the port being a second port in the hub, the hub comprising: a first port in fluid communication with the first lumen 10. The assembly of claim 1, further comprising: a second port configured to secure a proximal end of a stylet.

7. 7. The assembly of claim 6, wherein an outer diameter of the distal end of the stylet is equal to an inner diameter of the second port.

8. 10. The assembly of claim 1, wherein the exterior surface of the wall comprises at least one of a hydrophilic coating and a coating to reduce tissue adhesion.

9. 10. The assembly of claim 1, wherein the exterior surface of the wall includes markings for determining insertion depth.

10. 10. The assembly of claim 1, wherein the distal end portion of the sheath body is tapered and includes a tapered surface extending to a distal end surface, the distal end surface being perpendicular to a longitudinal axis of the sheath body.

11. The assembly of claim 10 , wherein the second lumen has an exit extending through a tapered surface of the distal end portion of the sheath body.

12. The assembly of claim 1 , further comprising a stabilization structure rotatably coupled to the tubular sheath body.

13. The assembly of claim 12, wherein the stabilization structure is rotatable about the longitudinal axis.

14. The assembly of claim 13 , wherein the stabilization structure includes features configured for suturing to a patient.

15. 15. The assembly of claim 14, wherein the stabilization structure includes a pair of suture wings, each wing having a plurality of ribs for securing a suture.

16. 10. The assembly of claim 1, wherein the sheath body is dimensioned to be introduced through a percutaneous access site of 6.67 mm or less.

17. 10. The assembly of claim 1, further comprising an intravascular blood pump.

18. 10. The assembly of claim 1, wherein the stylet is dimensioned to reduce a risk of clot formation in the second lumen.

19. 2. The assembly of claim 1, wherein the intravascular blood pump is a percutaneous intracardiac blood pump.

20. 10. The assembly of claim 1, wherein the first lumen comprises a first cross-sectional area that is greater than a second cross-sectional area of ​​the second lumen.

21. 10. The assembly of claim 1, wherein the first lumen has a proximal section having a first diameter and a distal section having a second diameter smaller than the first diameter.

22. The assembly of claim 1 , wherein the stylet includes a stylet body sized to occlude the second lumen when the stylet is positioned within the second lumen.

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