Dual lumen sheath for arterial access

CH 02995787 2018-02-13

WO 2017/031243

PCT/US2G16/047421

Dual Lumen Sheath for Arterial Access

Cross Referenceto Related Applications

[0001] This application claims the benefit of U.$. PatentApplication No. 14/827,741, filed on August17, 2015.

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10002] A blood pump, such as a percutaneous intracardiac blood pump assembly, is introduced in the heart to deliver bipod from the heart into an artery. When deployed in die heart, a Hood pump assembly pulls blood from the left ventricle of the heart and expels blood into Ihe aorta, orpulls blood from the right ventricle and expels blood Into the pulmonary artery. Blood pump assemblies are introduced surgically or percutaneously during a cardiac procedure through the vascular system. In one common approach, pump assemblies are inserted by a catheterization procedure through the femoral artery using a peel-away introducer sheath.

[0003] Ihe peel-away introducer sheath is inserted into the femoral artery through an arteriotomy to create an insertion path for the pump assembly. A portion of the pump assembly is then advancedthrough an inner lumen of the introducer and into the artery. Once the pump assembly has been inserted, the peel-away introducer sheath can be peeled away. A repositioning sheath can dien be advanced over the pump assembly and into the arteriotomy. Replacing the introducer sheath with the repositioning sheath can prevent blood clot formation in die. introducer sheath, prevent or reduce bleeding from the arteriotomy, and allow blood to flow through the femoral artery to the leg. But after the introducer sheath is removed, wire access to die artery is lost. Loss of the guide wire access makes it more difficult ip close the vessel after die procedure or to exchange devices in the arteriotomy.

[0004] To maintai n guidewire access, some physicians leave die peel-away introducer sheath in die arteriotomy for extended durations of time. The extended presence of die peelaway sheath in the arteriotomy can reduce recoil of the arteriotomy and thus increase the final diameter of the arteriotomy. This increase in diameter can increase die risk of bleeding

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PCT/US2016/047421 through, the arteriotomy once the peel-away introducer sheath is finally removed. Furthermore, the extendedpresence of the peel-away sheath in the arterycan reduce perfusion through the femoral artery, thereby increasing the risk of ischemia.

[0005] Additionally, clinicians sometimes choose to monitor a patient’s arterial pressure during the catheterization procedure. Measurement of the patient’s arterial pressure often requires the placement of an additional catheter. Thepresence of the additional catheter can add bulk to the operating area and requires entry' into the arterial system via another access point

Summary

[0006] Systems, methods, and devices for an improved dual lumen repositioning sheath are presented. The dual lumen sheath can be inserted into an arteriotomy afteran introducer sheath is removed to maintain guidewire access to die arteriotomy ; The dual lumen sheath includes a first lumen sized for passage ofa portion of a percutaneous pump and a second lumen sized for the insertion of a guidewire. The second lumen receives a guidewire to be

IS insertedinto the arteriotomy alongside a percutaneous pump to maintain guidew ire access to toe 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 a patient without losing toe guidewire access. This allows the physician to remove toe introducer sheath earlier in a procedure (e.g., I hour; 30 minutes, 10 minutes, 5 minutes, or immediately after successful insertion of thé percutaneous p ump), which allows toe blood vessel aperture to recoil to a smaller diameter compared to toe diameter it w ould assume if toe introducer sheath were left ra the patient for longer. For example, a repoli of 2 to 3French (0.667 mm to 1 uim) may be achieved iftoe introducer sheath is removed before toe blood vessel aperture permanently relaxes to the larger diameter of the introducer sheath.

[0007] The dual lumen sheath also includes a removable stylet that is inserted into the second lumen to reduce toe risk of blood dot formation in toe second lumen during the medical procedure. Maintaining the patency of toe second lumen is particularly helpful in procedures having a longer duration (eg, six. hours or longer). The removable stylet may be reversibly coupled to toe dual lumen sheath during insertion ofthc total lumen sheath into tote arteriotomy and duiing toe medical procedure. Before the percutaneous pump is removed, toe stylet is removed from thé second lumen to allow insertion of toe guidewire through toe second Inmen, Insome implementations, toe patency of toeguidewire port is maintained

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WO 2017/031243 PCT/US2016/047421 using a drug or nondrug coating applied to the second lumen. In certain implementations, the second lumen is flushed with a liquid at à controlled rate to maintain patency.

[0008] In some embodiments, the dual lumen sheath also includes a rotatable connection to a stabilizing structure (e.g.. suture pads). The rotatable connection allows the outlet of the second lumen at the distal end of the sheath to be rotated away from an arterial wall. This can facilitate the insertion of the guidewire by allowing the guidewire to be inserted in a direction not directly against the arterial wall, thereby reducing the friction associated with insertion of the guidewire. Additionally, the relation 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 provides a number of possible other advantages. For example, it also, allows arterial pressure to be transduced without the need for an additional catheter. Transducingthe pressure can allow a phy sicianto determine when the dual lumen sheath has been inserted to a sufficient depth If the second lumen is used to transduce pressure, die rotation of the guidewire outlet enabled by the rotatable connection to thestabilizingstructure can improvelhe reliability of the pressure measurement by keeping the outlet.of the second lumen off of the arterial-wall. Additionally, the second lumen can be used to determine tire depth of insertion without a pressure transducer. For example, the depth of insertion can be determined by observing the onset ofblood flow through the second lumen (“bleedback”), which is indicative of penetration into the arteriotomy. Regardless of whether a pressure transducer or a bleedbaek indicator is used, depth markings can be disposed on an outer surface ofthe sheath to facilitate measurement of die depth ofinsertion. The depth markings may be radio-opaque. The measurement ofthe depth of die arteriotomy relative to the patient’s skin can facilitate the subsequent use of certain vessel closure tools which may require such a measurement.

I0010J In one aspect, à sheath assembly for the insertion of a percutaneous pump includes a tubular Sheath body dimensioned for insertion into a blood vessel through a vessel aperture. The tubular sheath body includes a wall having a proximal end portion, a distal end portion, a longitudinal axis, mi 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 infier surface and the outer surface and extending from the proximal end portion to tire distal end portion. The first lumen is dimensioned to allow passage of a portion of die percutaneous pump, and die second lumen is dimensioned for passage ofa guidewire. A stylet is removably positioned to substantially occlude the second lumen.

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10011] Iii certain implementations, the stylet has a proximal end configured to be releasably secured to the sheath assembly, Insome implementations, the length of the stylet is substantially equal to the length of the second lumen. In certain implementations, the stylet is radio-opaque or includes radio-opaquemarker bands to show the distance of the sheath in die blood vessel. In certain implementations, the sheath assembly also includes a hub coupled to the proximal end portion ofthe sheath body and including a first port in fluid communication with the first lumen, and a second port in fluid communication with die second lumen, wherein the second port is configured to secure the proximal end ofthe stylet. The sheath body may be dimensioned to be introduced through a percutaneous access site of about 20 Fr (6.67mm} 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, 6Fr, orless),

[0012] In some implementations, the distal end portion of the sheath body is tapered and indudes a tapered surface extending to a distal end face, the distal end face being substantially orthogonal to the longitudinal axis ofthe sheath body'. In certain implementations, the second lumen has an outletextending through the tapered surface ofthe distal end portion of the sheath body. The second lumen may be coated with an antithrombogenic agent In some implementations, the outer surface of the wall of die tubular sheatit body includes ahydrophilic coating or any other suitable coating to prevent tissue adhesion. In some implementations file outer surface ofthe wall of the tubular sheath bod)' includes a hydrophilic coating or any other suitable coating to reduce frictional forces during insertion/removal of die sheath into the vasculature. In some implementations the outer surface of die wall of the tubular sheath body includes an antimicrobial coating or any other suitable coating to prevent or reduce infection risk. Additionally, in gome implementations file inner surface ofthe two lumens includes an antimicrobial coating or any other suitable coating to prevent or reduce infection risk. In certain implementations, the outer surface ofthe watt includes markings for determining adepth of insertion, for example with evenly spaced markings on die outer surface Ofthe wall.

|0013] tn certain implementations, flic sheath assembly also includes a stabilizing structure rotatably coupled to the tubular sheath body. The stabilizing structure may be rotatable about the longitudinal axis. In some implementations, the stabilizing structure includes a feature configured for suturing to a patient The stabilizing structure may include a pairofsutUre wings, each wing havingaplurality offibs forsecuring sutures.

[0014] hi another aspect, a method for maintaining guidewire access includes inserting a sheath info a blood vessel through a percutaneous insertion path and along a portion of a

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PCT/US2016/047421 percutaneous pump, wherein the sheath has a first lumen and a second lumen, maintaining the sheath in die vessel for more than 6hours while pre venring bloodclot formation from occluding foe second lumen, and inserting a guidewire through foe second lumen into the percutaneous insertion path after the more than 6 hours.

[001S J Iii some implementations, maintaining foe patency includes inserting a stylet into foe second lumen for more than 6 hours, and removing foe stylet before inserting the guidewire. In certain implementations, maintaining the patency includes flushing foe second lumen with purge fluid. In some implementations, die method the mefood dso mcludes removing the sheath while maintaining foe guidewire in foe percutaneous insertion path. In certain implementations, foe method also includes inserting a percutaneous tool over foe guidewire into foe percutaneous insertion path after foe sheath is removed. In some implementations, foe method also includes coupling a sensor to the proximal inlet of foe second lumen 'and transducing arterial pressure at the distal outlet of the second lumen using die sensor. In certamimplemcntations, the method also includes rotating foe sheath relative to a support structure when foe pressure measurement indicates that foe distal outlet is occluded by an arterial wall. In some implementations, the method also includes determining a depth of insertion from foe pressure measurement. The depth of insertion, may be determined using depth markers disposed on an outer surface of the sheath.

10016] Variations and modi fications will Occur to those of skill in foe art after reviewing this disclosure. Ihe disclosed features may be implemented, in any combination arid subcombination (including multiple, dependent combinations and subcombinations), with one or more other features described herein. The various features desenbed or illustrated above, including any components thereof, may be combined or integrated in other systems Moreover; certain features may be omitted or not implemented.

Brief Description of foe Drawings (0017} The foregoing and other objects and advantages will be apparent upon consideration of the following detailed description, taken in conjunction with foe accompanying drawings, in which like reference characters refer to tike parts throughout, and in which:

(0018] FIG 1 shows a top view of art illustrative dual lumen sheath for arterial access;

(0019] FIG. 2 shows alateral section view of the dual lumen sheath of FIG. 1;

(0020] FIG. 3 shows à transverse eross section ofthe distal portion of foe dual lumen sheath of FIG, 1;

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IÛ021] FIG. 4 shows a detailed section view of a distal portion of the dual lumen shealhof FIG. 1;

)0022] FIG. 5 shows tiie dual lumen sheath of FIG. 1 inserted into a blood vessel of a patient over a percutaneous pump; and )0023) FIG. 6 shows an illustrative process for maintainingguidewireaccess.

Detailed Description )0024] To provide an overall understanding of the systems, method, and devices described herein, certain illustrative embodiments will be described. Although the embodiments and features described herein are specifically described for use in connection with a percutaneous 10 blood pump system, it will be understood that ail the components and other features outlined below may be combined with one another in any suitable manner arid may be adapted arid applied to other types of cardiac therapy and cardiac assist devices, including balloon pumps, cardiac assist devices implanted using a surgical incision, andfoe tike.

)0025] The systems, methods, and devices described herein provide a dual lumen sheath 15 having a first lumen sized for passage of aportionof a percutaneous pump and à second lumen sized for insertion of a guidewire. The second lumen is positioned to allow the guidewire to be inserted into the insertion path of ihe percutaneous pump. This allows guide wire access to die insertion path to be maintained even after the percutaneous pump and dual lumen sheath are retracted. The guidewire access allows one or more other tools (e.g., a 20 vessel closure tool) to be subsequently inserted into foe same insertion path to facilitate vessel closure or any other medical procedures involving guidewire access. Because the second lymen enables a physician to maintain the guidewire access after the intrpducer sheath is removed, foe physician can remove foe introducer sheath earlier in a medical procedure. Earlier removal of foe introducer sheath allows foe insertion path to recoil to a smaller 25 diameter, thereby reducing foe risk of bleeding through the access site.

)0026] The systems, methods, and devices described herein also include a stylet that maintains foe patency of foe second lumen. The stylet is used to Occlude foe second lumen when foe second lumen is not being used for insertion of a guidewire or for pressure measurement. For example, foe removable stylet may be positioned within foe second lumen 30 during insertion of foe dual lumen sheath into the arteriotomy and during foe operation of foe percutaneeus pump. Before the percutaneous pump is removed, the stylet is removed from foe second lumen to allow insertion of the guidewire through the second lumen; Ute occlusion of foe second lumen with foe stylet can impede blood clot formation in foe second

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PCT/US2016/047421 lumen during medical procedures having along duration (e g./six hours or greater). This allows the second lumen to remain accessible during and after the medical procedure, for example to provide a path for insertion of die guidewire before removing thepercutancous pump. In some implementations, blood det formation is prevented using a drag or nondrug coating applied to thesecond lumen. Incertain implementations, blood clot formation is impeded by flushing the second lumen with a liquid at a controlled rate.

[0027] The dual lumen sheath may also include a rotatablc 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 be rotated away from an arterial wall. This can facilitate the insertion of the guidewire by allowing the guidewire robe inserted in a direction not directly against the arterial Wall, thereby reducing the friction associated with insertion of the guidewire. Additionally, the rotation allows the port for tire second lumen to lie substantially flat against the patient when the second lumen is not in use.

[00281 The second lumen can also establish fluid communicationbetwcena guidewire port and the interior of the blood vessel. Ibis can allow arterial, pressure measurement (e.g., by a pressure transducer) during a procedure without the use of a separate catheter. Measuring the arterial pressure can allow a physician to detect when the dual lumen sheath has been inserted to a sufficient depth into the vessel. The rotation of the guidewire outlet enabled by the rotatable connection to toe stabilizing structure can improve toe reliability' of toe pressure measurement by keeping the outlet of the second lumen off of toe arterial wall.

[0029] Figure 1 shows an illustrative dual hitncn sheath assembly 100 for maintaining arterial access, according to certain implementations. Figure 2 shows a lateral section view of the sheath assembly 100 taken along section line 2A and Figure 3 shows a transverse cross-section 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. anda stabilizing structure 150 . The tubular sheath body 102 is dimensioned for insertion into a blood vessel through a vessel aperture. In sense implementations, the tubular sheath body 102 is dimensioned for insertion mtoa femoral artery through an arteriotomy. The majority of toe tubular sheath body 102 may have a substantially uniform outer diameter 101 of about 10 Fr, 11 FL 12 Ft, 13, Fr, 15 Fr, 16Fr, 17 Fr, 20 Fr, or any other statable diameter. The tubular sheath body may be dimensioned to be introduced through a percutaneous access site of about 20 Fr (6 67mm) or smaller (e.g., 19FL 18 Fr, 17Fr, 16Fr, 15 Fr, J4Fr, 13 Fr, 12 Ft, 10 Fr, 9 Fr, 8 Fr, 6Fr, or less). The tubular sheath body may have a length of about 80 mm, 100 nun, 120 mm, 140 mm, 160 mm. or any other suitable length. Additionally, foe

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PCT/US2016/047421 tubular sheath body 102 may be made of a flexible material, such as polyether block amides or any other suitable polymer, to reduce die stress ou die blood vessel aperture.

(0030] The tubular sheath body 102 includes awali 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 1'18. Thedistal end portion 108 ofthe tubular sheath body 102 includes atapered surface 103. afirst outlet 105 in fluid eommunication with the first lumen 116, and a second outlet 107 in fluid communication with the second lumen 118. The tapered surface 103has an outer diameter graduatedfrom 11 Frto 15Fr (3.667 mmto 5 mm). The graduation in die tapered surface 103 may permit tire sheath to be inserted to a variable depth as necessary to plug the gap between the percutaneous pump and the insertion site .

[00317 The outer surface 112of the tubular sheath body 102 may be coated with a hydrophilic coating to ease insertion ofthe tubular sheath body 102 into die arteriotomy. A hydrophilic coating can also prevent adhesions to the blood vessel wall. Such adhesions could damage the vessel if the sheath is removed after having been in the blood vessel for an extended period of time (e.g., many days). The risk of adhesion to the Hood vessel wall can increase as the duration of a procedure increases. In some embodiments, the miter surface 112 of the tubular sheath body 102 includes depthmarkings. The depth markings may be pad printed or laser etched onto the outer surface 112. In certain implementations, die depth markings are radio-opaque. The depth markings may be in centimeters, indies, millimeters, or any other suitable unit of measurement or combination thereof:

|0032] The first inner surface 114 of the tubular sheath body defines the first lumen 116. The first lumen 116 is dimensioned to allow passage of aportionofthe percutaneous pump. The first lumen 116 extends from the proximal end poition406 of die tubular sheath body 102 to the distal end portion 108, substantially parallel to the longitudinal axis 110- The second lumen 118 is disposed within the wall 104 between die inner surface 114 and die outer surface 112. The second lunien 118 extends from die proximal end portion 106ofthe tubular sheath body 102 to die distal end portion 108, offset from and substantially parallel to the longitudinal axis 110 The second lumen 118is dimensioned for the passage of a guidewire and is defined by the second inner surface 115 (as shown in Figure S). The second inner surface 115 may include a drug or non-drug coating to prevent blood clot formation in the second lumen 118. In some implementations, thé second inner surface is coated with heparin. The second lumen 118 terminates at the second outlet 102 formed in die tapered surface 103. Ihe second cutlet l 02 is adjacent to the first outlet 105 ofthe first lumen 116.

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As a result, if a guidewire is inserted through the second lumen 118, the guidewire enters die insertion path of the percutaneous pump (not shown) passmgthrough thé first lumenl 16. Thus, the second lumen 118 may be used to maintain or regain guidewire access to the insertion path of a percutaneous pumpinserted throughthe first lumen 116, This allows guide wire access to the insertion path to be maintained even after an. introducer sheath is removed. The guidewire access allows one or more other tools to be subsequently inserted into the same insertion path to facilitate vessel closure or any other medical procedures involving guidewire access. For example, the guidewire access may permit the subsequent insertion of a vesselclosure toolor amicro pressure measurement catheterfe.g., MILLAR Mikro-Tip®· pressure catheter). A micro pressure measurement catheter may allow measurement of pressure m the left ventricle or any other suitable présure, Furthermore, since foe second lumen enables a physician to maintain guidewire access after the introducer sheath is removed, the physician can remove the introducer sheath earlier. Earlier removal of foe introducer sheath allows the vessel aperture to recoil to a smaller diameter, thereby reducing foe risk of bleeding through foe access site. Additionally , since the second outlet 107 is offset from the longitudinal axis 110, rotating the tubular sheath body 102 allow s foe position of the second outlet 107 to be adjusted. This can allow a user to keep foe second outlet 107 off of a blood vessel wall to ease insertion of a guidewire or to increase foe accuracy of an arterial pressure measurement.

[0033] The tubular sheath body 102 isconnected atits proximal end portion 10.6 to the hub 126. The hub 126 includes a first port 128, a second port 130, second port threads 131, and a bearing 136. The second port 130 is connected to foe second lumen 118 so that a guidewire Can be inserted through foe second port 130 into foe second lumen 118 and out of foe second outlet 107. When aguidewireis not in foe second lumen 118, foe stylet 120 can be inserted, into foe second port 130 to seal the secondlumen 118 (as shown in Figures 1,2, and 3). The stylet 120 includes ahead 121, a stylet body 122, a rounded end 123, and threads 126. The stylet body 122 is sized to substantially occlude foe second lumen 118 when foe stylet 120 is inserted into the second lumen 118. In some implementations, foe stylet body 122 is made of aformable or ductile material, such as a metal. Thismay allow foe stylet to be formed, either during foe medical procedure or before, into a shape that reduces stress on the vessel aperture. In certain implementations, foe stylet 120 is radio-opaque or includes radio-opaque marker bands to show foe depth of foe tubular sheath bpdy 102 in a blood vessel. The threads 124 of foe stylet head 121 reversibly couple with foe second port threads 131 to hold foe sty let 120 within the second lumen 118. When tiré stylet head 121 is.reversibly coupled to

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PCT/US2016/047421 the second port 130. the stylet head 121 forms a liquid tight seal across the second port 130, which prevcntsthe leakage of blood outof the blood vessel. In certain implementations, in place of the stylet 120, a pressure bag is connected to the second port 130using the threads 131, The pressure bag can be used to flush die second lumen 118 with à fluid to maintain the patency of the secondlumen 118.-. An infusion pumpmay be used in combination with the pressure bag to regulate the flow rate of liquid into the patient. For example, the flow rate may be limited to 1 mL/hr, 2mL/hr, 5 mL/hr, 10 mL/hr, or any other suitable flow rate. In some implementations, a pressure measuring device is connected to die second port 130 to measure pressure within die vessel 10- This pressure measurement can be used to determine when the second port 102 has been inserted sufficiently deep into the Mood vessel aperture. Far example, when a pressure about, equal to arterial pressure is measured at die 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 arterial pressure in the patient's blood vessel during a medical procedure; This may allow an arterial pressure measurement to be taken without die use of an additional catheter, which may reduce the amount of equipment necessary in tire potentially crowded operating area.

[0034} Thefirstport 128 ofthehub 126allowsthc passage of the percutaneous pump (not shown). Thefirstport 128 includes a cap 132 and a seal 134. Thecap 132 snaps into the first port 128 to hold die seal 134 against the first port 128. The cap 132 and seal 134 together act as a hemostatic valve and form a liquid tight seal between die percutaneous pump and the first port 128. The seal 134 is formed of an elastomer, such as silicone, so that it cah flex to seal around a portion Of the percutaneous pump.

[00351 The hub 126 is coupled, fo the stabilizing structure 150 by foe 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 wife die bearing 136. The mating ofthe bearing surface 164 of the stabilizing structure 150 with the bearing 136 of die hub 126 allows rotation ofthe hub 126 relative to die stabilizing structure 150. As discussed above, fois; rotation allows foe tubular sheath body 102 to be rotated such that the second outlet 107 is oriented away from a vessel wall. Additionally, this rotation allows the second port 130 to lie flat against a patient when the second port 130 is not m use. The suture holes 156-159 allow the wings 152 and 154 to be sutured to a patient to stabilize the sheafo assembly 100. While only four suture holes 156-159 are shown, any suitable number of suture holes may be used. The stabilizing structure 1501s also designed to be easily attached to a vascular graft with umbilical tape or sutures. This feature is beneficial during axillary insertions or any other insertions which

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PCT/US2016/047421 require pump placement through a vascular graft. Additionally, in some implementations, the stabilizing structure 150 is coupled to apatient using ribs 160-162. For example, sutures may be wrapped around the outer surface 165 of the stabilizing structure between the ribs 160162. When sutures are wrapped around the outer surface 165 in such a manner, the ribs 160162 prevent the sutures from sliding off of the outer surface 165 along the longitudinal axis 110. In certain implementations, cAher stabilization$ devices, such as surgical tape, a STATLGCK® stabilization device (Sard Access Systems, Ine., Salt Lake City, UI), or any other suitable adhesive stabilization device, may be coupled to the stabilizing structure 150 around die ribs 160-162.

[0036] Figure 4 shows a detailed section view ofthe distal portion 108 of die dual lumen sheath assembly 10Q of Figures 1, 2, and 3, The distal portion 108 includes the tapered surface 103, the first outlet 105, the second outlet 107, and distal portions of the stylet body 122, the first lumen 116, and die second lumen 118 Thé first lumen 116 includes a proximal section 116a having an inner diameter 117, a distal section 116b having an inner diameter 217 whi ch is less than die inner diameter 117, and a restriction 216 therebetween. The inner diameter 117 is about 13 Fr (4333 mm), and the inner diameter 217 is àbout 9 Fr (3mm). The restriction 216allows die distal section 116b of the first lumen 116 toform atighterfit with the percutaneous pump to prevent or reduce blood leakage without causing unacceptably high friction in the proximal section 116a. Similar to the first lumen 116, the second lumen 118 includes a proximal section 118a havinga diameter 119, a distal section 118b havinga diameter 219 that is less than die diameter 1 \9, 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 lighter fit between die stylet body 122 and the second lumen 118 at the distal section 118a to reduce blood ingress, while allowing a clearance in the proximal section 118b to reduce friction, The friction between die second fumeri 118 and die stylet body 122 is further reduced by the rounding of die end 123 of the stylet body 122, The rounded end 123 is located adjacent to die second outlet 107 when the stylet 120 is fully inserted into the second lumen 118, thereby preventing or reducing blood ingress into the second lumen 118, [0037] Figure 5 shows die dual lumen sheath assembly 100 of FIG. linserted into a.blood vessel Ifiof a patient ovefa percutaneous pump60. The percutaneouspump 60 includesa pump head 66 and a catheter body 62. The percutaneous pump 60 may be an intravascular blood pump, a blood pump driven by flexible dri ve-shaft, a blood pump including an implantable motor, a blood pump having an expandable pump rotor, or any other suitable pump. The dual lumen sheath assembly lOO is advanced into die blood vessel 10 over the

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PCT/US2016/047421 catheter body 62 of the percutaneous pump 60 through the blood vessel aperture 12in the direction indicated by arrow 70. The first lumen 116 af the dual lumen sheath assembly 100 may be threaded on the catheter body 62 when the percutaneous pump 60 is initially inserted into the blood vessel 10. The blood vessel 10 may be a femoral artery, and the blood vessel aperture 12 may be an arteriotomy. The blood vessel aperture 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 may effectively plug the gap betw een the blood vessel aperture 12 and the catheter by 64 when the sheath assembly lOO is advanced into the blood vessel 10 over M catheter body 62. The outer diameter 101 of thetubular sheath body' 102 may be graduated as discussed above to so that the diameter l Olof 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 farther into the blood vessel lOOtoplug a larger gap between the blood vessel aperture 12 and the catheter body 62. Thé plugging effect of the tubular sheath body 102 can reduce or prevent bleeding out of toe blood vessel aperture 12. The tubular sheath body 102 is flexible so that tire tubular sheath body 102 can form a bend 80 which allows the tubular sheath body 102 to follow thé. contours of the vessel 10. This flexibility can reduce the stress placed on.toe blood vessel aperture 12 by reducing the force required to deform the tubular sheath body 102.

|0038] Once the tubular sheath body 102 has been advanced over the catheter body-62 of the percutaneous pump 60 to a sufficient depth to plug tire gap between the vessel aperture 12 and the catheter body 62, the dual lumen sheath assembly W0 maybe fixed relative to the catheter body 62. This fixation may be achieved by fixing the stabilizing structure 150 to toe patient’S tissue 14. In some implementations, this is achievedby suturing wings (not shown) of the stabilizing structure 150 to the patient tissue 14. In certain implementations, the stabilizing structure 150 is attachedto a vascular graft with umbilical tape or suturés. This may be performed during axillary insertions or any other insertions which require pump placement through a vascular graft, In some implementations, fixing the placement of toe dual lumen sheath assembly 100 may be achieved by tightening toe seal 134 around the catheter body 62 or by means of a separate anchoring ring. The second port 130 may be rotated relative to toe stabilizing structuré 150 so that toe second port 130 lies fiat gainst toe patient tissue 14. After toe dual lumen sheath assembly 100 lias been fixed in toe appropriate positi on, aphysician may begin operation of the percutaneous pump 60. The percutaneous pump 60 may be operated during a percutaneous coronary intervention (PCI), open-heart surgery, heart valve replacement surgery, or during treatment of acute myocardial infarction

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PCT/US2016/047421 (AMI), cardiogenic shock, or ST segment elevation myocardial infarction (STEM1), as well as any other suitable medical procedure. In certain implementations, the percutaneous pump 60 is operated for an extended period of time, such as greater than six hours, greater than 12 hours, greater than 24 hours, greater than 48 hours, greaterthan 72 hours, greater than one week, or any other suitable duration of time. In such cases, a stylet (not shown in Figure ?), such as the stylet 120 from Figures 1-4 , may be positioned within the second lumen 118 during insertion of the dual lumen sheath assembly 100 to prevent blood ingress into flic second lumen 118, which could lead to clotting, that could obstruct flic second lumen 118 or to bleeding out of the second port 130.

[0039] bi certain implementations, the second port 130 of the dual lumen sheath assembly 100 is used to deliver contrast media, (e.g. iodine or barium compounds) into a blood vessel to visualize blood flow.

|0040] In certain implementations, a pressure bag is connected to the second port 130 in place οίφβ stylet to maintain the patency: of the second lumen 118 , An infusion pump maybe used in combination with the pressure bag to regulate the flow rate of liquid into the patient. For example, the flowrate may be limited to I mL/hr, % mL/hr, 5 mL/hr, 10 mL/hr, or any other suitable flow rate. In some implementations, a pressure measuring device is connected to the second port 130 to measure the pressure within the vessel 10. This pressure measurement can be used to determine when the second port 102 has been inserted sufficiently deep into the blood vessel aperture 12. For example, when a pressure about equal to arterial pressure is measured atthe second port 130, the second outlet 107 may be in fluid communication with the blood vessel 10. After penetration into the blood vessel aperture 12 has been detected, the depth of flic blood vessel aperture 12 relative to the patient's skin can be measured using depth markings disposed on an outer surface of the sheath. The measurement of this depth can facilitate the subsequent use of certain vesselclosuretools which may require such a measurement The pressure measurement can also be used to monitor arterial pressure in the Hood vessel 10 during a medical procedure. This roay allow an arterial pressure measurement to be taken without the use of an additional catheter, which may reduce the amount of equipment necessary in the potentially crowded operating area. Additionally, the second lumen 118 can allo wa determination of the depth of insertion without a pressure transducer by allowing observation of the onset of blood flow through the second lumen 118 fHeedback®), which is indicative Of penetrationinto thé blood vessel aperture 12.

43·

Date Reçue/Date Received 2023-05-11

CA 02»»A707 Mte-02-13

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PCT/US2016/047421 |«M1] When it is time to remove the percutaneous pump 60_? a guidewire 50 is inserted through, the second port 130 into the second lumen 118 and out the second outlet 107 into the blood vessel 10. Thus, the guidcwire50 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 lumensheath assembly 100, the stylet is removed before insertion of the guidewire 50. The guidewire 50 has an outer diameter that approximately matches tire inner diameter of the second outlet 107 to prevent blood from flowing out ofthe blood vessel 10 through the second port 130. For example, the guidewire may have an outer diameter of about 1 nun. Additionally, in some implementations, a seal at the second port 130 is lnchided to further ensure that no blood exits the second port 130 while die guidewire 50 is in place. [0042} After the guidewire. 50 has been placed in thé blood vessel 10, the percutaneous pump 60 and the dual lumen sheath assembly 100 may be removed through the blood vessel aperture 12 while the guidewire 50 isleft m place. The tubular sheath body 102 may be coated with a hydrophilic coating or any other suitable coating that prevents adhesions to the blood vessel 10, thereby facilitating removal of the tubular sheath body 102 without damaging die blood vessel 10- The removal of thedual lumen sheathassembly 100 and percutaneous pump 60 while the guidewire 50 is left in place allows guidewire access to tire insertion path Π to be maintained. The removal of the percutaneous pump 60 requires the concurrent removal of the duallumen sheath assembly 100 because die 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 tightly’ around the diameter 64 of the catheter body 62, but cannot accommodate the laiger diameter 68 of the pump head 66. Asaresuft, the first lumen 116 is not available to beused to maintain guidewire access to the insertion pad! 11. Thus, the second lumen 118 is necessary to maintain .guidewire access to the insertion path 41.

10043] After die percutaneous pump 60 aid the. dud lumen sheath assembly 100 hâve been removed, the guidewire 50 remains in the blood vessel 10 and die insertion path 11. Thus, another tool may be inserted over the guidewife 30 info die insertion path 11. In some implementations, a vascularclosure device is inserted info the insertion path 11 using the guidewire 50. The vascular closure device may be theVASOSEAL vascular sealing device, the ANGIO-SÈAL ™ bio-absorbable active closure system, the PERCLOSE™ vascular sealing device, or any other suitable vascular closure device or combination of vascular closure devices. After a vascular closure device or other device has been successfully inserted through die vessel aperture 12 into thc insertion path ll,the guidewire 5 0 may be removed from the vessel aperture 12.

44Date Reçue/Date Received 2023-05-11

CA 02»»»707 ¢018-02-13

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PCT/US2016/047421 (0044] Figure 6 shows an illustrative process 600 for maintaining guidewire access The illustrative 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 andasecond lumen The blood vessel may be an artery, such as the femoral artery·. The insertion path passes through a blood vessel aperture (e g., an arteriotomy). The percutaneous pump is inserted into the insertion path using an introducer prior to step 602. Therefore, the percutaneous pump guides the sheath info fee existinginseriion path. The percutaneous pump may be an intravascular blood pump, a blood pump driven by flexible drive shaft, a blood pump including an implantable motor, a blood pump having an expandable pump rotor, or any other suitable pump, Thcfirstlumen ofthe sheath may be sealed against fee percutaneous pump by a hemostatic valve to prevent leakage of blood from the blood vessel out of the patient.

[0045} Insome implementations, the sheath is only inserted into fee vessel as deep as is necessary to close the gap between the percutaneous pump and fee vessel.aperture toprevent bleeding. To reliably detect whether fee sheath has been inserted sufficiently deep into fee vessel, the pressure within the vessel can be detected using fee second lumen. For example, a detected pressure about equalto arterial pressure may indicate feat theoutlet ofthe second lumen has been inserted into fee blood vessel. Alternatively, the second lumen can allow a determination of fee. depth of insertion without a pressure transducer by allowing observation of fee onset of bipod flow through the second lumenflrieedback”), which isindicative of penetration into the blood vessel aperture. After penetration into the blood vessel aperture has been detected, fee depthof fee blood vessel aperture relative to fee patient's skin can be measured using depth markings disposed on an outcr surface ofthe sheath In some implementations, the depth markings are radio-opaque and can be imaged using a tomographic imaging modality (eg., CT, MRÏ, X-ray). The measurementof this depth can facilitate fee subsequent use of certain vessel closure tools which may require such à measurement. Additionally, once inserted to the appropriate depth, the second lumen¹ can be used to measure arterial pressureduring the procedure.

[0046] In step 604, fee sheath is maintained in the vessel for about six hours or more while blood clot formation is prevented from occluding the second lumen. The sheath may be maintained m fee vessel for 6 hours, 12 hours, 24 hours, 48 hours, 72 hours, one week, two weeks, or any other suitable duration of time. Blood clot formation in the second lumen may be prevented during this time using a stylet that temporarily occludes the second lumen. For

45Date Reçue/Date Received 2023-05-11

CA osmw ΜΙβ-02-13

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PCT/US2016/047421 example, the stylet 120 of Figures 1-3 may be used to temporarily occlude the second lumen, incertain implementations, blood clot formation in the second tumen is prevented or reduced using admg ornondrug coatingin the second lumen.. The coating mayinclude heparin or any other suitable substance. In sonic implementations, bloodclot formation in the second lumen is preventedor reduced by flushing die. second lumen with a liqiiid<e.g., saline solution, glucose solution, or any other suitable solution). Preventing the occlusion of the second lumen by blood clots allows the patency of the second lumen to be preserved for insertion of a guide wire.

[0047] In step 606, a guidewire is inserted through die Second .lumen into the percutaneous insertion path after the about six hours or more. If a stylet was used to temporarily occlude the second luihen, the stylet is removed before inserting die guidewire. The percutaneous pump Inserted through die first lumen may be removed after insertion of the guidewire. After the guidewire has been inserted, the Sheath may be removed from the percutaneous insertion path while the guidewire remains in place. This can allow another tool (e.g., an access closure tool) to be inserted into Ihe insertion path. This frees a physician from depending on an introducer to maintain guidewife access. Thus, die physician is able to remove the introducer earlier in a procedure. This can allow greater recoil of the blood vcssel apcrture, thereby reducing die risk of bleeding. For example, removing die introducer Within an hour of insertion may allow a recoil of about 2 to 3 Fr (0.667 min to 1 mm).

[0048] The foregoing is merely illustrative of die principles of the disclosure, and the systems, methods, and devices can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation. It is to be understood that the systems, methods, and devices disclosed herein, whifoshown for use in a system percutaneous intravascular blood pumps, may be applied to systems, methods, and devices for other implantable blood pumps or implantable cardiac assist devices.

[0049] Variations and modifications’will occur to those of skill in die art after reviewing this disclosure. For example, in some implementations, the sheath assembly may be used to provide guidewire access for procedures of a short duration (e.g., less than six hours). Furthermore, the stylet may be omitted in some implementations in which tire patency of the second lumen is adequately maintained by' other means. For example, in some implementations, tire second lumen is flushed with a liquid, either intermittently or continuously. The disclosed features maybe implemented, in any combination and subcombination (including multiple dependent combinations and subcombinafions), with one or more other features described herein. The various features described or illustrated above.

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PCT/US2O16/O47421

CA 02»»707 Μ1β-02-13 including any components thereof, may be combined or integrated in oflier systems.

Moreover certain: features may be omitted or not implemented.

|0050] Examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the scope of the information disclosed herein.

47Date Reçue/Date Received 2023-05-11