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 August 17, 2015, which is incorporated herein 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 via a catheterization procedure using a peel-away introducer sheath.

[0003] A peel-away introducer sheath is inserted through the arteriotomy into the femoral artery to create 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 can reduce arteriotomy retraction and therefore increase the final diameter of the arteriotomy. This increased diameter can increase the risk of bleeding from the arteriotomy after the peel-away introducer sheath is ultimately removed. Furthermore, the prolonged presence of the peel-away sheath in the artery can reduce perfusion through the femoral artery, thereby increasing the risk of ischemia.

[0005] Additionally, clinicians may choose to monitor the patient's arterial blood pressure during the catheterization procedure. Measuring the patient's arterial blood pressure 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 an 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 a percutaneous pump and a second lumen sized for insertion of a guidewire. The second lumen receives a guidewire inserted into the arteriotomy along with the percutaneous pump, maintaining guidewire access to the percutaneous pump's insertion path. Maintaining guidewire access using the second lumen of the dual-lumen sheath allows the introducer sheath to 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 percutaneous pump insertion), allowing the vascular opening to return to a smaller diameter than it would have if the introducer sheath had remained 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 to 3 French (0.667 mm to 1 mm) can be achieved.

[0007] The dual-lumen sheath also includes a removable stylet inserted into the second lumen to reduce the risk of clot formation in the second lumen during a medical procedure. Maintaining patency of the second lumen is particularly useful in procedures requiring longer durations (e.g., six hours or more). The removable stylet can be reversibly coupled to the dual-lumen sheath during insertion of the dual-lumen sheath into the arteriotomy and throughout the medical procedure. The stylet is removed from the second lumen before the percutaneous pump is removed, allowing for 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 guidewire insertion 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 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 a 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 pressure measurements by keeping the second lumen outlet away from the arterial wall. Additionally, the second lumen can also be used to determine insertion depth without a pressure transducer. For example, insertion depth can be determined by observing the onset of blood flow through the second lumen ("bleedback"), which indicates penetration of 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 insertion depth. The depth markings can be radiopaque. Measurement of the arteriotomy depth 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 sized 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, 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 and outer surfaces and extending from the proximal end portion to the distal end portion. The first lumen is sized to allow passage of a portion of the percutaneous pump, and the second lumen is sized 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 can 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 the distal end surface, which is 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 from the vasculature. In some embodiments, the outer surface of the wall of the tubular sheath body includes an antibacterial coating or any other suitable coating to prevent or reduce the risk of infection. Additionally, in some embodiments, the inner surfaces of the two lumens include an antibacterial coating or any other suitable coating to prevent or reduce the risk of infection. In certain embodiments, the outer surface of the wall includes markings for determining insertion depth, for example, markings evenly spaced on the outer surface of the wall.

[0013] In certain embodiments, the claimed sheath assembly also includes a stabilizing structure rotatably coupled to the tubular sheath body. The stabilizing structure may be rotatable about a longitudinal axis. In some embodiments, the stabilizing structure includes features configured for suturing to a patient. The stabilizing 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 into the percutaneous insertion pathway through the second lumen.

[0015] In some embodiments, maintaining patency includes inserting a stylet into the second lumen for more than six hours and removing the stylet before inserting the guidewire. In certain embodiments, maintaining patency includes flushing the second lumen with a purge 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 over 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 measurement indicates that the distal outlet is blocked by the arterial wall. In some embodiments, the method also includes determining the depth of insertion from the pressure measurement. The depth of insertion can be determined using depth markers located on the 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 implemented in any combination and subcombination (including multiple subcombinations and subcombinations) with one or more other features described herein. The various features, including any component parts thereof, may be combined or integrated into other systems. Moreover, certain features may be omitted or not implemented. [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 vascular 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 allow 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 sized for passage of a guidewire; and a stylet having a proximal end releasably secured to the sheath assembly and positioned to substantially occlude the second lumen; , a sheath assembly. [The present invention 1002] The 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 antithrombotic agent. [The present invention 1006] The sheath body further includes a hub coupled to the proximal end portion thereof, 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] The sheath assembly of the present invention 1001, wherein the outer surface of the wall includes markings for determining the depth of insertion. [The present invention 1009] The sheath assembly of the present invention 1001, 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 substantially perpendicular to the 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 stabilizing structure rotatably coupled to the tubular sheath body. [The present invention 1012] The sheath assembly of the present invention 1011, wherein the stabilization structure is rotatable about the longitudinal axis. [The present invention 1013] The sheath assembly of the present invention 1012, wherein the stabilizing structure includes features configured for suturing to a patient. [The present invention 1014] A sheath assembly according to the present invention 1013, wherein the stabilizing 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 sized 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. A method comprising: [The present invention 1017] 1016. The method of claim 1016, wherein maintaining patency comprises inserting a stylet into the second lumen for more than 6 hours and removing the stylet before 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 into the percutaneous insertion pathway along the guidewire after removing the sheath. [The present invention 1021] coupling a sensor to the 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] 1021. A method according to 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] 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] These 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 explanation of the drawings]

[0018] [Figure 1] 1 illustrates a top view of an exemplary dual lumen sheath for arterial access. [Figure 2]2 shows a side cross-sectional view of the dual lumen sheath of FIG. 1. [Figure 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. [Figure 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 INVENTION

[0019] Detailed Description Certain exemplary embodiments will be described to provide an overall understanding of the systems, methods, and devices described herein. While 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 for use with 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 percutaneous pump's insertion path. This allows guidewire access to the insertion path to be maintained even after the percutaneous pump and dual-lumen sheath are withdrawn. Guidewire access allows one or more other devices (e.g., a vascular closure device) to be inserted into the same insertion path later to facilitate vascular closure or any other medical procedure involving guidewire access. Because the second lumen allows the physician to maintain guidewire access even after the introducer sheath is removed, the physician can remove the introducer sheath early 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 within 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 insertion of a guidewire through the second lumen. Occlusion of the second lumen by the stylet can prevent clot formation in the second lumen during medical procedures requiring an extended period of time (e.g., six hours or more). This allows the second lumen to remain accessible during and after the medical procedure, for example, to provide a route for guidewire insertion before removal of the percutaneous pump. In some embodiments, 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 guidewire insertion 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, according to 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 transverse cross-sectional view of the 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 French, 11 French, 12 French, 13 French, 14 French, 15 French, 16 French, 17 French, 20 French, or any other suitable diameter. The tubular sheath body can 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 can have a length of about 80 mm, 100 mm, 120 mm, 140 mm, 160 mm, or any other suitable length. Additionally, the tubular sheath body 102 can be fabricated 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 gradually changes from 11 French to 15 French (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 can also prevent adhesion to the vessel wall. Such adhesion can damage the vessel if the sheath is left in the vessel for an extended period of time (e.g., days) and then removed. The risk of adhesion to the vessel wall can increase with increasing duration of the procedure. 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 unit of measure, or a combination thereof.

[0027] The first inner surface 114 of the tubular sheath body defines a first lumen 116. The first lumen 116 is sized to allow passage of a portion of a percutaneous pump therethrough. 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. A 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, offset from and substantially parallel to the longitudinal axis 110. The second lumen 118 is sized 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 a percutaneous pump (not shown). Thus, the second lumen 118 can be used to maintain or restore guidewire access to the insertion path of a 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 later inserted into the same insertion path to facilitate vascular closure or any other medical procedure involving guidewire access. For example, guidewire access may allow for the 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 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 so that a guidewire can be inserted into the second lumen 118 through the second port 130 and exit through 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 metal. This may allow the stylet to be formed 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 within 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, preventing blood from leaking from the blood vessel. In certain embodiments, a pressure bag is connected to the second port 130 using the threads 131 instead 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 may 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 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 needed 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 hemostatic 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 a 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 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 requiring placement of a pump through the graft. Additionally, in some embodiments, the stabilizing structure 150 is coupled to the patient using the ribs 160-162. For example, a suture may be wrapped around the outer surface 165 of the stabilizing structure between the ribs 160-162. When the suture is wrapped around the outer surface 165 in this manner, the ribs 160-162 prevent the suture 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 a tapered surface 103, a first outlet 105, a second outlet 107, and distal portions of a stylet body 122, a first lumen 116, and a 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, preventing or reducing 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 diameter 119, and a restriction 218 therebetween. Diameter 119 is approximately 1.1 mm, and diameter 219 is approximately 1 mm. The restriction 218 allows a tighter fit between the stylet body 122 at the distal section 118a and the second lumen 118, reducing 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 rounding 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 outlet 107 , thereby preventing or reducing blood from entering 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 the catheter body 62 of the percutaneous pump 60 in the direction indicated by arrow 70 through a vascular 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 onto the catheter body 62. The blood vessel 10 may be a femoral artery, and the vascular opening 12 may be an arteriotomy. The vascular 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 varied 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 and 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 so 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 the 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 sufficiently deep 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 securing may be achieved by securing the stabilizing structure 150 to the patient's tissue 14. In some embodiments, this is achieved 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 requiring placement of the pump through the graft. In some embodiments, securing the placement of the dual-lumen sheath assembly 100 may be achieved 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 so that it lies flat against the patient's tissue 14. After the dual-lumen sheath assembly 100 is secured in place, the physician may begin operating 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 could result in clotting that could 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, an iodine or barium compound) into the blood vessel for visualization of blood flow.

[0035] In certain embodiments, a pressure bag is connected to the second port 130 instead of a 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 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 can be used to determine when the second port 102 has been inserted sufficiently deep into the vascular opening 12. For example, when a pressure approximately equal to arterial pressure is measured at the second port 130, the second outlet 107 may be in fluid communication with the blood vessel 10. After penetration of the vascular opening 12 is detected, the depth of the vascular opening 12 relative to the patient's skin can be measured using depth markings located on the exterior surface of the sheath. This depth measurement can facilitate subsequent use of certain vascular closure devices that may require such a measurement. 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 needed at a potentially complicated surgical site. Additionally, second lumen 118 may allow for determination of insertion depth without a pressure transducer by allowing for observation of the onset of blood flow ("bleed back") through second lumen 118, 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 before inserting 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 exiting the blood vessel 10 through the second port 130. For example, the guidewire may have an outer diameter of approximately 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 while leaving 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. Removing the dual lumen sheath assembly 100 and percutaneous pump 60 while leaving the guidewire 50 in place allows guidewire access to the insertion path 11 to be maintained. Removal of the percutaneous pump 60 requires simultaneous removal of the dual lumen sheath assembly 100 because the diameter 68 of the pump head 66 cannot pass through the first lumen 116. This is 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 path 11. Therefore, the second lumen 118 is necessary to maintain guidewire access to the insertion path 11.

[0038] After the percutaneous pump 60 and dual lumen sheath assembly 100 are removed, the guidewire 50 remains in the blood vessel 10 and 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 pathway 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 pathway passes through a vascular opening (e.g., an arteriotomy). Prior to step 602, a percutaneous pump is inserted into the insertion pathway using an introducer. Thus, the percutaneous pump guides the sheath into the existing insertion pathway. 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 blood leakage from the patient's blood vessel, the first lumen of the sheath may be sealed off from the percutaneous pump by a hemostatic valve.

[0040] In some embodiments, the sheath is inserted into the blood vessel only deep enough to close the gap between the percutaneous pump and the vascular opening to prevent bleeding. To reliably detect whether the sheath has been inserted sufficiently deep into the blood vessel, the second lumen can be used to detect intravascular pressure. For example, a detected pressure approximately equal to arterial pressure can indicate that the outlet of the second lumen has been inserted into the blood vessel. Alternatively, the second lumen can enable the determination of insertion depth without a pressure transducer by allowing observation of the onset of blood flow through the second lumen ("bleed back"), which indicates penetration of the vascular opening. After penetration of the vascular opening is detected, the depth of the vascular opening relative to the patient's skin can be measured using depth markings located on the outer surface of the sheath. In some embodiments, the depth markings 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 devices that may require such measurements. Additionally, once inserted to the appropriate depth, the second lumen can be used to measure arterial pressure during the procedure.

[0041] In step 604, the sheath is maintained in the blood vessel for approximately 6 hours or more while preventing clot formation from blocking the second lumen. The sheath can be maintained in the blood 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 occludes 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 occlude 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 clots from blocking the second lumen allows the second lumen to remain patent for guidewire insertion.

[0042] In step 606, after approximately six 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 inserting the guidewire. 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 device (e.g., an access closure device) to be inserted into the insertion pathway. This may free the physician from relying on the introducer device to maintain guidewire access. Therefore, the physician may remove the introducer device earlier during the procedure. This may allow for greater retraction of the vascular opening, thereby reducing the risk of bleeding. For example, removing the introducer device within one hour of insertion may allow for retraction of approximately 2 to 3 Fr (0.667 mm to 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 ways than those presented by way of example 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 procedures (e.g., less than six hours). 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 intermittently or continuously with a fluid. The disclosed features may be implemented 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 implemented.

[0045] Examples of changes, 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. A sheath assembly for insertion of a percutaneous pump, comprising: The sheath assembly includes: A tubular sheath body sized for insertion into a blood vessel through a vascular opening, said 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 allow passage of at least a portion of the percutaneous pump, the wall and the first lumen including a proximal section, a distal section, and a restriction between the proximal and distal sections; 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 second lumen being dimensioned for passage of a guidewire, the second lumen including a proximal section, a distal section, and a restriction between the proximal and distal sections.

2. The sheath assembly of claim 1 , further comprising a stylet positioned to substantially occlude the second lumen and having a proximal end releasably secured to a proximal end portion of a wall of the sheath assembly.

3. The sheath assembly of claim 2 , 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 sheath assembly of claim 3 , wherein the distal section diameter is approximately equal to an outer diameter of the stylet.

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

6. a hub coupled to a proximal end portion of the tubular sheath body, the hub comprising: a first port in fluid communication with the first lumen; and The sheath assembly of claim 2, including a second port in fluid communication with the second lumen, the second port configured to secure a proximal end of the stylet.

7. The sheath assembly according to claim 1 , wherein the outer surface of the wall includes at least one of a hydrophilic coating and a coating to reduce tissue adhesion.

8. The sheath assembly of claim 1 , wherein the outer surface of the wall includes markings for determining insertion depth.

9. The sheath assembly of claim 1 , wherein the distal end portion of the wall 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 wall.

10. The sheath assembly of claim 9 , wherein the second lumen has an exit extending through a tapered surface of the distal end portion of the wall.

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

12. The sheath assembly of claim 11 , wherein the stabilization structure is rotatable about a longitudinal axis.

13. The sheath assembly of claim 12 , wherein the stabilizing structure includes features configured for suturing to a patient.

14. The sheath assembly of claim 13, wherein the stabilizing structure includes a pair of suture wings, each wing having a plurality of ribs for securing a suture.

15. The sheath assembly of claim 1 , wherein the tubular sheath body is sized to be introduced through a percutaneous access site of about 20 Fr (6.67 mm) or less.

16. The sheath assembly of claim 2 , wherein a length of the stylet is substantially equal to a length of the second lumen.

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