Device delivery tool

Abstract

The percutaneous circulatory assist system includes a percutaneous circulatory assist device including an impeller disposed within an impeller housing, the impeller rotatable relative to the impeller housing to effect blood flow through the impeller housing. The system further includes a cannula coupled to the impeller housing and a cannula delivery tool configured to receive and radially compress the cannula, the cannula delivery tool having a proximal portion disposed adjacent the tapered portion and a distal portion disposed adjacent the tapered portion.

Description

Technical Field

[0001] The present disclosure relates to devices used to facilitate intravascular delivery of medical devices. More specifically, the present disclosure relates to a percutaneous circulatory assist system having a cannula and a device for facilitating delivery of the cannula through a delivery sheath.

Background Art

[0002] Certain medical devices, such as circulatory assist devices, are delivered intravascularly. Introduction of such devices into the vascular system often involves passing the device through one or more delivery sheaths and then guiding the device through the patient's vascular system to its final position. In the case of a circulatory assist device placed on the left side of the heart, the device is typically introduced into the femoral artery and passed through the vascular system until it enters the aorta. Next, a cannula incorporated into the device is passed through the aortic valve and into the left ventricle. Due to the size and structure of such devices, particularly the cannulas incorporated into circulatory assist devices, passage of the device through the delivery sheath can be difficult.

Summary of the Invention

[0003] In Example 1, a percutaneous circulatory assist system includes a device including a housing and a cannula coupled to the housing, and a cannula delivery tool configured to receive the cannula and compress it radially, the cannula delivery tool having a proximal portion positioned adjacent a tapered portion and a distal portion positioned adjacent the tapered portion.

[0004] In Example 2, the system of Example 1 further includes that the cannula delivery tool is a laser-cut tube and the cannula delivery tool includes a plurality of closed cells. In Example 3, the system of Example 1 further includes that the percutaneous circulatory assist system includes a starter tube for receiving the cannula delivery tool and the cannula, and the cannula delivery tool is configured to compress when inserted into the starter tube.

[0005] In Example 4, the system of Example 3 further includes that the percutaneous circulatory assist system further includes an introducer sheath, the introducer sheath has an inner diameter, and when the cannula delivery tool is compressed, the cannula delivery tool is defined by an outer diameter smaller than the inner diameter of the introducer sheath.

[0006] In Example 5, the system of Example 1 further includes that the cannula delivery tool is composed of nitinol. In Example 6, the system of Example 1 further includes that a proximal portion of the cannula delivery tool includes a curved plate extending to a first side of the cannula delivery tool, and a tether extends from the curved plate and extends proximally to couple with the introducer sheath.

[0007] In Example 7, the system of Example 1 further includes that the cannula delivery tool includes a surface coating along the surface of the cannula delivery tool. In Example 8, the system of Example 4 further includes that the friction coefficient between the cannula and the introducer sheath is greater than the friction coefficient between the cannula delivery tool and the introducer sheath.

[0008] In Example 9, the system of Example 6 further includes that the system further includes a guide wire extending within the cannula delivery tool and the cannula, the guide wire extends through a second side of the cannula delivery tool, and the second side is on the opposite side of the first side with respect to the longitudinal axis of the cannula delivery tool.

[0009] In Example 10, a method of deploying a percutaneous device includes providing a percutaneous assist system including a percutaneous device having at least a housing coupled to a cannula, a handle for operating the percutaneous assist system, a starter tube mounted on a catheter of the percutaneous assist system, a cannula delivery tool mounted on the catheter, and an introducer sheath. The method further includes extending the cannula delivery tool over the cannula, retracting the cannula delivery tool and the percutaneous assist device into the starter tube, inserting the starter tube at least partially into the introducer sheath, extending the cannula delivery tool out of the distal portion of the starter tube and at least partially out of the distal portion of the introducer sheath, and extending the cannula out of the cannula delivery tool.

[0010] In Example 11, the method of Example 10 further includes compressing the cannula delivery tool such that the cannula delivery tool has an outer diameter smaller than the inner diameter of the introducer sheath by retracting the delivery tool into the starter tube.

[0011] In Example 12, the method of Example 10 further includes, the percutaneous assist system further including a guide wire, and the method further including extending the guide wire through the cannula delivery tube and the percutaneous assist device before extending the cannula delivery tool over the cannula.

[0012] In Example 13, the method of Example 12 further includes, the percutaneous assist system further comprising a tether coupled to the introducer sheath and the cannula delivery tool, such that the length of the tether determines how far the cannula delivery tool extends out of the introducer sheath.

[0013] In Example 14, the method of Example 10 further includes further including retracting the tether to retract the cannula delivery tool into the starter tube through the introducer sheath.

[0014] In Example 15, the method of Example 11 further includes that the cannula delivery tool is provided with a tapered portion and a surface treatment, both of which are configured to be compressible when the cannula delivery tool is retracted into the start tube.

[0015] In Example 16, the percutaneous circulatory assist system includes a percutaneous circulatory assist device including an impeller disposed within an impeller housing, the impeller being rotatable relative to the impeller housing to create a blood flow through the impeller housing. The system further includes a cannula coupled to the impeller housing and a cannula delivery tool configured to receive the cannula and compress it radially, the cannula delivery tool having a proximal portion positioned adjacent to the tapered portion and a distal portion positioned adjacent to the tapered portion.

[0016] In Example 17, the system of Example 16 further includes that the cannula delivery tool is a laser-cut tube and the cannula delivery tool includes a plurality of closed cells. In Example 18, the system of Example 16 further includes that the percutaneous circulatory assist system includes a starter tube for receiving the cannula delivery tool and the cannula, and the cannula delivery tool is configured to be compressed when inserted into the starter tube.

[0017] In Example 19, the system of Example 18 further includes that the percutaneous circulatory assist system further includes an introducer sheath having an inner diameter, and when the cannula delivery tool is compressed, the cannula delivery tool is defined by an outer diameter smaller than the inner diameter of the introducer sheath.

[0018] In Example 20, the system of Example 16 further includes that the cannula delivery tool is composed of nitinol. In Example 21, the system of Example 16 further includes that a proximal portion of the cannula delivery tool comprises a curved plate extending to a first side of the cannula delivery tool, and a tether extends from the curved plate and extends proximally to couple with the introducer sheath.

[0019] In Example 22, the system of Example 21 further includes that the system further comprises a guidewire extending within the cannula delivery tool and the cannula, the guidewire extends through a second side of the cannula delivery tool, and the second side is on an opposite side of the first side with respect to the longitudinal axis of the cannula delivery tool.

[0020] In Example 23, the system of Example 16 further includes that the cannula delivery tool includes a surface coating along the surface of the cannula delivery tool. In Example 24, the system of Example 23 further includes that the surface coating is silicone.

[0021] In Example 25, the system of Example 19 further includes that the coefficient of friction between the cannula and the introducer sheath is greater than the coefficient of friction between the cannula delivery tool and the introducer sheath. In Example 26, a cannula delivery tool configured to deliver a cannula includes a proximal portion opposite the distal portion and a body portion extending therebetween. The body portion includes a tapered portion, a curved plate extending from the proximal portion configured to facilitate introduction of the cannula delivery tool into the sheath, and a plurality of closed cells along the body portion formed by laser cutting a tube forming the cannula delivery tool.

[0022] In Example 27, the cannula delivery tool of Example 26 further includes that a tether is coupled to the curved plate and extends proximally from the curved plate of the cannula delivery tool, and the tether is welded to the curved plate.

[0023] In Example 28, the cannula delivery tool of Example 26 further includes that the cannula delivery tool is composed of one of nitinol and stainless steel and that the cannula delivery tool includes a surface treatment.

[0024] In Example 29, the cannula delivery tool of Example 26 further includes that the cannula delivery tool is configured to compress from an expanded form having an expanded outer diameter to a compressed form having a compressed outer diameter.

[0025] In Example 30, a method of deploying a percutaneous assist device includes providing a percutaneous assist system including a percutaneous assist device having at least an impeller housing coupled to a cannula, a handle for operating the percutaneous assist system, a starter tube mounted on a catheter of the percutaneous assist system, a cannula delivery tool mounted on the catheter, and an introducer sheath. The method further includes extending the cannula delivery tool over the cannula, retracting the cannula delivery tool and the percutaneous assist device into the starter tube, and inserting the starter tube at least partially into the introducer sheath. The method further includes extending the cannula delivery tool out of the distal portion of the starter tube and at least partially out of the distal portion of the introducer sheath, and extending the cannula out of the cannula delivery tool.

[0026] In Example 31, the method of Example 30 further includes compressing the cannula delivery tool such that the step of retracting the delivery tool into the starter tube is such that the cannula delivery tool has an outer diameter smaller than the inner diameter of the introducer sheath.

[0027] In Example 32, the method of Example 30 further includes that the percutaneous assist system further includes a guide wire and that the method further includes extending the guide wire through the cannula delivery tube and the percutaneous assist device before extending the cannula delivery tool over the cannula.

[0028] In Example 33, the method of Example 32 further includes that the percutaneous assist system further comprises a tether coupled to the introducer sheath and the cannula delivery tool, such that the length of the tether determines how far the cannula delivery tool extends out from the introducer sheath.

[0029] In Example 34, the method of Example 30 further includes that the method further includes the step of retracting the tether to retract the cannula delivery tool into the starter tube through the introducer sheath.

[0030] In Example 35, the method of Example 31 further includes that the cannula delivery tool comprises a tapered portion and a surface treatment, both configured to be compressible when the cannula delivery tool is retracted into the start tube.

[0031] Although multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which illustrates and describes exemplary embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

Brief Description of the Drawings

[0032]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0033] Without departing from the scope of the present invention, various modifications and additions can be made to the exemplary embodiments described. For example, the above-described embodiments refer to specific features, but the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the above-described features.

[0034] FIG. 1 shows a side cross-sectional view of some components of an exemplary percutaneous circulatory assist system 100, according to an embodiment of the subject matter disclosed herein. Generally, system 100 includes a percutaneous circulatory assist device 102 (also interchangeably referred to herein as a “blood pump”), a cannula 116, and an introducer sheath 134 (shown in FIG. 2A). In some embodiments, system 100 may also include a guide wire 120 (shown in FIG. 2A). As will be described in more detail below with reference to FIG. 7, introducer sheath 134 facilitates the percutaneous delivery of blood pump 102 and cannula 116 to a target location within a patient, such as within the patient's heart.

[0035] Continuing to refer to FIG. 1, system 100 also includes a handle 104 connected to a starter tube hemostatic valve 106. The starter tube hemostatic valve 106 is coupled to both a starter tube 108 and a starter tube flushing line 110. The handle 104 may also be coupled to a proximal catheter 112. The starter tube 108 is illustrated as being coupled to a cannula delivery tool 170 configured to receive the cannula 116 before and during delivery of the blood pump 102 and the cannula 116, as further described herein. In these embodiments, at least the handle 104, the starter tube 108, the starter tube hemostatic valve 106, the introducer sheath 134 (FIG. 3), and the cannula delivery tool 170 are configured to deliver the blood pump 102 and the cannula 116 to a target location within a patient, as further described herein. In some embodiments, a guidewire 120 (FIG. 2) may also be used to facilitate delivery of the percutaneous circulatory assist device 102. Although described herein with reference to the percutaneous circulatory assist system 100, the cannula delivery tool 170 may be used for delivery of a variety of other types of medical devices and is not limited to the examples described herein.

[0036] As illustrated in FIG. 2A, the blood pump 102 generally includes an impeller assembly housing 140 and a motor housing 142. In some embodiments, the impeller assembly housing 140 and the motor housing 142 may be constructed integrally or monolithically. In other embodiments, the impeller assembly housing 140 and the motor housing 142 may be separate components configured to be removably or permanently coupled.

[0037] The impeller assembly housing 140 carries an impeller assembly 144 therein. The impeller assembly 144 includes an impeller shaft 146 and an impeller 148 that rotates relative to the impeller assembly housing 140 and drives blood through the blood pump 102. More specifically, the impeller 148 flows blood from a blood inlet 150 formed on the impeller assembly housing 140, through the impeller assembly housing 140, and out through a blood outlet 152 formed on the impeller assembly housing 140. In some embodiments, the impeller shaft 146 and the impeller 148 may be integrated, and in other embodiments, the impeller shaft 146 and the impeller 148 may be separate components. As shown in FIGS. 1 and 2, the inlet 150 and / or the outlet 152 may each include a plurality of openings. In other embodiments, the inlet 150 and / or the outlet 152 may each include a single opening. As shown in FIG. 2A, the inlet 150 may be formed at an end of the impeller assembly housing 140, and the outlet 152 may be formed at a side of the impeller assembly housing 140. In other embodiments, the inlet 150 and / or the outlet 152 may be formed at other portions of the impeller assembly housing 140. In some embodiments, the impeller assembly housing 140 may be coupled to a distally extending cannula (not shown), and the cannula may receive blood and deliver it to the inlet 150.

[0038] Continuing to refer to FIG. 2A, the motor housing 142 carries a motor 154, which is configured to rotatably drive the impeller 148 relative to the impeller assembly housing 140. In the illustrated embodiment, the motor 154 rotates a drive shaft 156 coupled to a drive magnet 158. Rotation of the drive magnet 158 causes rotation of a driven magnet 160 connected to the impeller assembly housing 140. More specifically, in embodiments incorporating the impeller shaft 146, the impeller shaft 146 and the impeller 148 are configured to rotate with the driven magnet 160. In other embodiments, the motor 154 may be coupled to the impeller assembly housing 140 via other components.

[0039] In some embodiments, a controller (not shown) may be operably coupled to the motor 154 and configured to control the motor 154. In some embodiments, the controller may be disposed within the motor housing 142. In other embodiments, the controller may be disposed outside the motor housing 142 (e.g., within a catheter handle, a separate housing, etc.). In some embodiments, the controller may include a plurality of components, one or more of which may be disposed within the motor housing 142. According to an embodiment, the controller may be one or more field programmable gate arrays (FPGAs), one or more programmable logic devices (PLDs), one or more complex PLDs (CPLDs), one or more custom application specific integrated circuits (ASICs), one or more dedicated processors (e.g., microprocessors), one or more central processing units (CPUs), software, hardware, firmware, or any combination of these and / or other components, may include them, or may be included in them. Although the controller is referred to herein in the singular, the controller may be implemented in multiple instances, may be distributed across multiple computing devices, may be created within multiple virtual machines, and / or the like. In other embodiments, the motor 154 may be controlled in other ways.

[0040] Figure 2A shows a partial cross-sectional view of various components of the system 100 after insertion into the blood vessel V, and the process is further described with reference to FIG. 7. Specifically, FIG. 2A illustrates the proximal portion 172 of the cannula delivery tool 170 and the percutaneous circulatory assist device 102 positioned within the introducer sheath 134 such that the introducer sheath 134 surrounds the cannula delivery tool 170 during at least a portion of the delivery process of the blood pump 102. For example, the introducer sheath 134 has an inner diameter 192 that is larger than the compressed outer diameter 194 of the cannula delivery tool 170 such that the cannula delivery tool 170 fits completely circumferentially within the introducer sheath 134. In this way, the cannula delivery tool 170 is positioned between the introducer sheath 134 and at least a portion of the percutaneous circulatory device 102.

[0041] Figure 2B shows a partial cross-sectional view of various components of the system 100 after insertion into the blood vessel V. Specifically, FIG. 2B illustrates the distal portion 174 of the cannula delivery tool 170 compressed onto the cannula 116 and the cannula delivery tool 170 positioned within the introducer sheath 134. Similar to the exemplary embodiment of FIG. 2A, the cannula delivery tool 170 is configured to have a compressed outer diameter 194. In this way, the cannula delivery tool 170 is positioned between the introducer sheath 134 and the cannula 116, and thus the cannula 116 does not contact the introducer sheath 134 directly. This can provide the benefit of reducing the frictional force between the introducer sheath 134 and the cannula 116 that would otherwise occur, as further described herein. The cannula 116 and the cannula delivery tool 170 are described with reference to use with the percutaneous circulatory assist device 102, but various other percutaneous circulatory assist devices that may differ from the device 102 may be used. Further, the cannula 116 and the cannula delivery tool 170 may be used with any of a variety of percutaneous devices and delivery systems. The cannula delivery tool 170 is described in further detail herein.

[0042] FIG. 3 shows a top view of an expanded configuration of the cannula delivery tool 170 having an expanded outer diameter 196 that is larger than the compressed outer diameter 194 as shown in the configuration of FIG. 2. Additionally, the cannula delivery tool 170 includes a proximal portion 172, a distal portion 174, and a body portion 176 that extends between the proximal portion 172 and the distal portion 174 along a longitudinal axis L. At least a portion of the body portion 176 includes a tapered portion 178 that may be configured to assist in retracting the cannula delivery tool 170 into the starter tube 108 (FIG. 1) as further described with reference to FIG. 7. Additionally, the body portion 176 of the cannula delivery tool 170 is defined by a plurality of closed cells 180 machined into the cannula delivery tool 170. In some embodiments, the cannula delivery tool 170 is constructed from a metallic material such as nitinol or stainless steel that is laser cut to form the plurality of closed cells 180. The use of laser cutting or otherwise machining the plurality of closed cells 180 allows openings to be formed in the cannula delivery tool 170 that can contribute to the cannula delivery tool 170's ability to be compressible and expandable while still minimizing the thickness of the cannula delivery tool 170. For example, in conventional methods, a braided design may be used to create a plurality of closed cells within the delivery tool. However, the braided design increases the thickness of the delivery tool because the materials must be woven and form intersections where portions of the materials are stacked on top of each other. This can be disadvantageous when the delivery tool needs to be positioned within an additional structure, such as in the case of the cannula delivery tool 170 described herein. Additionally, in some embodiments, the cannula delivery tool 170 has a surface coating, such as silicone or PET, to optimize surface properties during delivery as further described with reference to FIG. 7. In further embodiments, the surface coating may be any other lubricious coating or surface treatment that may reduce the coefficient of the cannula delivery tool 170.

[0043] Continuing to refer to FIG. 3, the proximal portion 172 includes a plate 182. As shown, the plate 182 is curved, extends proximally to the cannula delivery tool 170, and is coupled to the tether 184. The plate 182 may be laser cut from the cannula delivery tool 170 or otherwise machined. The plate 182 is shown having an apex 185 that extends to a first side 186 of the device, where the first side 186 is defined as the first side 186 of the device with respect to the longitudinal axis L of the cannula delivery tool 170. The first side 186 may be referred to as the upper side of the cannula delivery tool 170. Embodiments herein are shown with the proximal portion 172 including a plate 182, but in other embodiments, the cannula delivery tool 170 does not include a plate 182. In these embodiments, the delivery tool 170 may have an end formed in a similar configuration to the configuration of the distal portion 174 and / or the body portion 176.

[0044] FIG. 4 shows a side view of the cannula delivery tool 170 of FIG. 3 and shows a tether 184 extending proximally from the plate 182. In various embodiments, the tether 184 may be a separate wire welded to the plate 182. When welded, the tether 184 may include a weld protection surface coating to increase the stability of the tether 184. For example, heat shrink may be incorporated around the tether 184. In further embodiments, the tether 184 may be formed by laser cutting the original tube forming the cannula delivery tool 170. In these embodiments, the advantage may be provided that the tether 184 is formed integrally with the cannula delivery tool 170, reducing the possibility of breakage at the attachment point. Various other embodiments of the tether may be incorporated, and additional manufacturing methods may be envisioned.

[0045] FIG. 5 shows an enlarged cross-sectional view of the proximal portion 172 of the cannula delivery tool 170 having a plate 182 coupled to the tether 184. The tether 184 extends along the same side as the plate 182, illustratively the first side 186. The tether 184 may additionally comprise a radiopaque marker to assist the physician in identifying the position of the tether 184 and thus the cannula delivery tool 170 during delivery. As previously disclosed, the guidewire 120 may be used in combination with an exemplary percutaneous circulatory assist system 100 to deliver the percutaneous circulatory assist device 102 and the cannula 116. For example, FIG. 5 shows the cannula delivery tool 170 used with the guidewire 120. Due to the configuration of the plate 182 extending only on the first side 186 of the cannula delivery tool 170, the guidewire 120 has an open and relatively unobstructed passage into the cannula delivery tool 170 on the second side 188 of the cannula delivery tool 170. The second side 188 is positioned opposite the first side 186 with respect to the longitudinal axis L. This can increase the ease with which the guidewire 120 can pass through the cannula delivery tool 170 because there is an integrated opening formed for the guidewire 120 within the cannula delivery tool 170 and the interaction between the guidewire 120, the cannula 116, and the cannula delivery tool 170 during insertion of the guidewire 120 can be reduced. However, as described above, the exemplary percutaneous circulatory assist system 100 can also be used without the guidewire 120.

[0046] Further, FIG. 6 shows the distal portion 174 of the cannula delivery tool 170 in more detail. Specifically, the distal portion 174 of the cannula delivery tool 170 provides a non-traumatic end 174a and may thus be designed to function to reduce severe and / or sharp impacts on the vasculature by the cannula delivery tool 170 during delivery, or any damage. Additionally, the cannula delivery tool 170 may not remove calcifications that may be present in the vessel wall when the distal portion 174 includes the non-traumatic end 174a. For example, the exemplary embodiment of FIG. 6 shows various configurations of a plurality of closed cells 180 having rounded apexes 190 extending distally from the distal portion 174. The rounded apexes 190 provide the advantage of a less rough or sharp contact than would be present if a protruding or pointed end were incorporated. Although illustrated as having rounded apexes 190, the distal portion 174 may be configured to provide this non-traumatic end 174a.

[0047] FIG. 7 shows a method 200 of delivering a percutaneous circulatory assist device, such as the percutaneous circulatory assist device 102 described with reference to FIGS. 1 and 2, using the cannula delivery tool 170. The following method 200 is described with reference to FIG. 7 and the components as shown at least in FIGS. 1 and 2.

[0048] In block 202, the method includes first providing a percutaneous assist system, such as the percutaneous circulatory assist system 100. Further, in block 204, the method 200 includes extending the cannula delivery tool 170 over the cannula 116 of the exemplary percutaneous circulatory assist system 100. The step of extending the cannula delivery tool 170 over the cannula 116 may include positioning the cannula delivery tool 170 such that the entire cannula 116 is surrounded by the cannula delivery tool 170. During this step, the cannula delivery tool 170 is in an expanded configuration having an expanded outer diameter 196 (FIG. 3) to facilitate positioning on the cannula 116.

[0049] Additionally, method 200 includes the step shown in block 206 of retracting cannula delivery tool 170 and percutaneous circulatory assist device 102 into starter tube 108. Thus, cannula delivery tool 170, cannula 116, and percutaneous circulatory assist device 102 are retracted into starter tube 108 in preparation for insertion into the patient's body. During this step, cannula delivery tool 170 is configured to compress from an expanded outer diameter 196 (FIG. 3) to a compressed outer diameter 194 (FIGS. 2A and 2B), such that cannula delivery tool 170 fits within starter tube 108 and ultimately within introducer sheath 134. The ability of cannula delivery tool 170 to compress to have a compressed outer diameter 194 is due at least in part to the curved shape of plate 182, the tapered portion 178 of cannula delivery tool 170, and the material forming cannula delivery tool 170. During this step, cannula delivery tool 170 may be compressed to the compressed outer diameter 194 such that cannula delivery tool 170 is in direct contact with cannula 116.

[0050] In block 208, method 200 includes the step of inserting starter tube 108, which includes cannula delivery tool 170 and circulatory assist device 102, into introducer sheath 134. In various embodiments, introducer sheath 134 is already positioned at least partially within a patient's artery, such as the patient's femoral artery.

[0051] In block 210, method 200 further includes the step of extending the cannula delivery tool 170 out of the starter tube 108 and partially out of the introducer sheath 134. This step further includes that, as shown, for example, in FIG. 2, when the cannula delivery tool 170 is pushed out of the starter tube 108, the starter tube 108 is not fully extended out of the distal portion of the introducer sheath 134 such that the cannula delivery tool 170 is in direct contact with the interior of the introducer sheath 134. As a result of the cannula delivery tool 170 being positioned at the compressed outer diameter 194, the cannula delivery tool 170 is already configured to fit within the introducer sheath 134 when deployed from the starter tube 108. As described above, the cannula delivery tool 170 includes a surface coating that can increase the ease with which the cannula delivery tool 170 slides within the introducer sheath 134. Additionally, the plurality of laser cut closed cells 180 formed within the cannula delivery tool 170 can also increase the ease with which the cannula delivery tool 170 slides within the cannula delivery tool 170 because, as opposed to the use of a braided structure, the cannula delivery tool 170 comprises one major layer of material rather than an intersection of stacked materials. More specifically, the cannula delivery tool 170 can have a coefficient of friction that is less than the coefficient of friction that occurs during contact between the introducer sheath 134 and the cannula 116 when the cannula delivery tool 170 is in contact with the introducer sheath 134. In this way, the use of the cannula delivery tool 170 provides an advantage to the exemplary percutaneous circulatory assist system 100 in that there is less friction during deployment of the cannula 116 through the introducer sheath 134, which otherwise could cause defects in the delivery process, including failure and damage to components.

[0052] Referring again to FIG. 7, during the steps in block 210, the cannula delivery tool 170 that still surrounds the cannula 116 extends out from the distal portion of the introducer sheath 134. However, the extent to which the cannula delivery tool 170 extends is limited by the tether 184 because the tether 184 couples the cannula delivery tool 170 to the introducer sheath 134. The tether 184 also enables the ability to retract the cannula delivery tool 170 into the introducer sheath 134 when desired. As the cannula delivery tool 170 extends out from the distal portion of the introducer sheath 134, the cannula delivery tool 170 expands radially. In various embodiments, the cannula delivery tool 170 expands radially such that it is again defined by the expanded outer diameter 196 of the cannula delivery tool 170.

[0053] Method 200 then includes the step in block 212 of extending the cannula 116 out from the cannula delivery tool 170. During this step, the cannula 116, and thus the percutaneous circulatory assist device 102 coupled to the cannula 116, is released from the cannula delivery tool 170. The circulatory assist device 102 can then be deployed into the patient's heart through the patient's vasculature. Once the circulatory assist device 102 exits the cannula delivery tool 170, the cannula delivery tool 170 can be retracted into the introducer sheath 134 and further into the starter tube 108. When retracted into the introducer sheath 134, the diameter of the cannula delivery tool 170 is compressed as further described herein.

[0054] Furthermore, in various embodiments, the exemplary percutaneous circulatory assist system 100 may include a guidewire 120 for use in deploying cannulas 116 and 102. For example, in these embodiments, prior to extending a cannula delivery tool over the cannulas, method 200 includes extending guidewire 120 through cannula delivery tool 170, specifically through the first side 186 and through percutaneous circulatory assist device 102 as discussed with reference to FIG. 5. Guidewire 120 may be used to assist in the delivery and positioning of cannulas 116 and percutaneous circulatory assist device 102.

[0055] Additionally, in embodiments, method 200 may include retracting tether 184 and retracting cannula delivery tool 170 through introducer sheath 134 and into starter tube 108 for removal. This step is optimized by the curved shape of plate 182 of cannula delivery tool 170, specifically, the curved shape of plate 182 allows cannula delivery tool 170 to be more easily captured within introducer sheath 134 and compressed back to its compressed outer diameter 196 (FIGS. 2A and 2B).

[0056] Cannula delivery tool 170 and cannula 116 are described throughout as being used with percutaneous circulatory assist system 100 for delivering percutaneous circulatory assist device 102, but cannula delivery tool 170 and cannula 116 may be used with a variety of different systems. Specifically, cannula delivery tool 170 may also be used with a variety of different medical devices such as devices including balloons, stents, or other radially compressible and expandable devices introduced into blood vessels. The embodiments described herein are not intended to be limiting and are provided by way of example only.

[0057] Without departing from the scope of the present invention, various modifications and additions can be made to the exemplary embodiments described. For example, although the above-described embodiments refer to specific features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to encompass all such alternative, modified, and variant forms that fall within the scope of the claims, together with all of their equivalents.

Claims

1. An apparatus including a housing and a cannula coupled to the housing, A cannula delivery tool configured to receive and radially compress the cannula, the cannula delivery tool including a proximal portion positioned adjacent to a tapered portion and a distal portion positioned adjacent to the tapered portion, A starter tube for receiving the cannula delivery tool and the cannula, the cannula delivery tool being configured to compress when inserted into the starter tube, A percutaneous circulatory assist system including the above.

2. The percutaneous circulatory assist system according to claim 1, wherein the cannula delivery tool is a laser-cut tube and the cannula delivery tool includes a plurality of closed cells.

3. The percutaneous circulatory assist system according to claim 1, further including an introducer sheath, the introducer sheath having an inner diameter, and when the cannula delivery tool is compressed, the cannula delivery tool being defined by an outer diameter smaller than the inner diameter of the introducer sheath.

4. The percutaneous circulatory assist system according to claim 1, wherein the cannula delivery tool is composed of nitinol.

5. The percutaneous circulatory assist system according to claim 3, wherein the proximal portion of the cannula delivery tool includes a curved plate extending on a first side of the cannula delivery tool, and a tether extends from the curved plate and extends proximally to couple with the introducer sheath.

6. The percutaneous circulatory assist system according to claim 1, wherein the cannula delivery tool includes a surface coating along the surface of the cannula delivery tool.

7. The percutaneous circulatory assist system according to claim 3, wherein a coefficient of friction between the cannula and the introducer sheath is greater than a coefficient of friction between the cannula delivery tool and the introducer sheath. **Claim 8** The percutaneous circulatory assist system according to claim 5, further comprising a guide wire extending within the cannula delivery tool and the cannula, the guide wire extending through a second side of the cannula delivery tool, the second side being on an opposite side of the first side with respect to a longitudinal axis of the cannula delivery tool.

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