Implantable medical device separation system with split tube

Abstract

The present invention is entitled "Implantable Medical Device Separation System with Split Tubes". The present invention provides a separation system for delivering an implantable medical device to a target location in a body vessel, the separation system having a substantially hollow distal tube. The distal tube includes a proximal end, a distal end, and a compressible portion of the tube itself, the compressible portion being able to move axially from a compressed condition to an elongated condition between the proximal end and the distal end. The substantially hollow proximal tube has a proximal end and a distal end. A coupling system engages and deploys an implantable medical device engaged at the distal end of the distal tube. When engaging the implantable medical device, the coupling system moves the compressible portion to the compressed condition, deploys the implantable medical device, and releases the compressible portion to the elongated condition.

Description

Technical Field

[0001] The present invention generally relates to interventional medical device systems that are navigable within a body vessel of a human subject. More particularly, the present invention relates to separate systems for deploying implantable medical devices to a target location within a body vessel and methods of using the separate systems. Background Art

[0002] The use of catheter delivery systems for positioning and deploying therapeutic devices (such as dilatation balloons, stents and embolic coils) in the vascular system of the human body has become a standard procedure for treating intravascular diseases. It has been found that such devices are particularly useful in areas where traditional treatment procedures are impossible or pose a great risk to patients (for example, in the treatment of aneurysms in intracranial blood vessels). Due to the delicate tissues around intracranial blood vessels, especially brain tissue, it is very difficult and often risky to perform surgical procedures to treat defects in intracranial blood vessels. In such cases, improvements to catheter deployment systems provide alternative treatments. Some of the advantages of catheter delivery systems are that catheter delivery systems provide methods for treating blood vessels by being found to reduce the risk of trauma to surrounding tissues, and catheter delivery systems also allow treatment of blood vessels that would have been considered inoperable in the past.

[0003] Typically, these processes involve inserting the distal end of a delivery catheter into the patient's vascular system and guiding the delivery catheter through the vascular system to a predetermined delivery site. A vascular occlusive device (such as an embolic coil) is attached to the end of a delivery member that pushes the coil through the catheter and leaves the distal end of the catheter to the delivery site. Some of the problems associated with these processes are related to ensuring the complete release and deployment of the coil. For example, U.S. Patent No. 5,250,071 to Palermo describes a separation system whereby the interlocking buckles of the system and the coil are held together by a control line, which is hereby incorporated by reference herein. The control line is moved proximally to disengage the buckles from each other. However, the system does not include any forward device for separating the disengaged buckles from each other, so only retracting the control line cannot ensure the release and deployment of the coil. Many other separation systems currently in use also have similar problems.

[0004] In addition, U.S. Pat. No. 8,062,325 discloses a single tubular carrier to deliver and deploy a vascular occlusive device, but only has a single compressible segment. Thus, there remains a need for a more rapid release detachment system or method that can ensure the release and deployment of an implantable medical device. Additional advantages can also be achieved using a detachment system or method that incorporates a simple and inexpensive locking and deployment system. Summary of the invention

[0005] The separation system delivers the implantable medical device to a target location of a body vessel with a generally hollow distal tube. The distal tube has a proximal end, a distal end, and a compressible portion of the distal tube itself, which can be axially moved from a compressed state to an elongated state, and the compressible portion is between the proximal end and the distal end. It also includes a generally hollow proximal tube, which has a proximal end and a distal end, and the proximal tube and the distal tube are combined; and a coupling system, which engages and deploys the implantable medical device engaged at the distal end of the distal tube. When engaging the implantable medical device, the coupling system moves the compressible portion to a compressed state, deploys the implantable medical device, and releases the compressible portion to an elongated state.

[0006] For another example, when the implantable medical device is engaged, the engagement system can be removably fixed to the proximal end of the distal tube to maintain the compressed condition. Moreover, when the implantable medical device is engaged, the engagement system can be removably fixed to the proximal end of the proximal tube.

[0007] An example of an engagement system has a locking member and a loop. When the loop interacts with the locking member to engage the implantable medical device, the force on the loop moves the compressible portion to a compressed condition, and the loop is welded to the proximal end of the distal tube to removably secure the engagement system. The force on the locking member releases the loop, disengaging the implantable medical device and allowing the compressible portion to return to an extended condition.

[0008] Other examples have a compressible portion of the distal tube as a spiral cut portion of the distal tube. When the compressible portion moves to an extended condition, the compressible portion may be adapted to deploy an implantable medical device engaged by the engagement system. Additionally, when the engagement system is disengaged from the implantable medical device, the compressible portion of the distal tube is adapted to automatically / elastically move to an extended condition. The proximal tube may also include a flexible portion of the proximal tube itself that is flexible between the proximal end and the distal end, and the distal tube may include a flexible portion of the distal tube itself that is flexible between the proximal end and the compressible portion.

[0009] The method of separating the implantable medical device using the above example may include the following steps: forming a compressible portion on the distal tube between the proximal end and the distal end; engaging the implantable medical device with a coupling system; applying a force to the coupling system to compress the compressible portion; fixing the coupling system to the distal tube to maintain the compressed state; and combining the distal tube and the proximal tube together. As above, the coupling system can be removably fixed to the proximal end of the distal tube.

[0010] The separation method example may also have the step of removably securing the engagement system to the proximal end of the proximal tube when engaging the implantable medical device. The engaging step may include the step of engaging the implantable medical device using a loop having a locking member; and the applying step further includes the step of applying a force to the loop to move the compressible portion to the compressed condition. Other example steps include applying a force to the locking member; disengaging the implantable medical device; and allowing the compressible portion to return to the extended condition.

[0011] An example of the forming step may include the step of spirally cutting a portion of the distal tube and further having the step of deploying the implantable medical device engaged by moving the compressible portion to the extended condition. Additionally, the compressible portion of the distal tube may be adapted to automatically / elastically move to the extended condition when the engagement system is disengaged from the implantable medical device.

[0012] Additionally, the bonding step further includes the step of welding the proximal tube to the distal tube at a welding zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other aspects of the present invention are further discussed with reference to the following detailed description and in conjunction with the accompanying drawings, in which the same reference numerals indicate the same structural elements and features in various figures. The accompanying drawings are not necessarily drawn to scale, but instead, emphasis is placed on illustrating the principles of the present invention. The accompanying drawings depict one or more specific implementations of the apparatus of the present invention by way of example only and not by way of limitation.

[0014] Figure 1A is an exploded view of an example of a separation system of the present invention, wherein the medical device is partially disengaged;

[0015] Figure 1B yes Figure 1A A magnified image of

[0016] Figure 2 is an exploded view of an example of a separation system of the present invention wherein a medical device is engaged;

[0017] Figure 3A is a side perspective view of an example of a loop line according to the example;

[0018] Figure 3B is a plan view of an example of a loop line according to another example;

[0019] Figure 4 is a front perspective detail view of the opening of the loop in an alternate example in a flipped-up condition;

[0020] Figure 5A is an exploded view of an example of a separation system of the present invention, wherein the medical device is engaged and the loop wire is secured;

[0021] Figure 5B is an enlarged view of the loop fixed to the distal tube;

[0022] Figure 6 is a plan view of the gap between the proximal tube and the distal tube;

[0023] Figure 7 is a plan view of the proximal tube and the distal tube welded together;

[0024] Figure 8 The proximal weld at the small tube is shown;

[0025] Fig. 9 An exemplary method of forming the separation system of the present invention is shown;

[0026] Figures 10A-10D shows a medical device separated in partial cross section;

[0027] Fig.11 is a side view of an example of a distal tube in a compressed state and an expanded state; and

[0028] Fig.12 is a front perspective view of an example of a medical device being separated. DETAILED DESCRIPTION

[0029] The accompanying drawings illustrate generally hollow or tubular structures according to the present invention. As used herein, the terms "tubular" and "tube" are to be interpreted broadly and are not limited to structures that are right cylindrical or have a strictly circular cross section or a uniform cross section throughout their length. For example, tubular structures or systems are generally shown as structures that are substantially right cylindrical. However, tubular systems may have tapered or curved outer surfaces without departing from the scope of the present invention.

[0030] like Figure 1A , Figure 1B and Figure 2 The example of the detachment system 10 of the present invention shown may have a proximal elongated delivery hypotube assembly 100 and a distal delivery tube 300. An implantable medical device 12 is engaged at one end of the distal delivery tube 300. The implantable medical device 12 may be an embolic coil, but it should be understood that substantially any implantable medical device 12 may be delivered and deployed by the detachment system 10 according to the present invention. The medical device 12 is engaged to the system using a locking member 140 and a loop wire 400. The medical device 12 has a locking portion 18 to interface with the engagement system 140, engagement system 400.

[0031] The proximal delivery tube 100 may have a proximal end portion 102, a distal end portion 104, and a flexible portion 106 therebetween. The proximal delivery tube 100 defines an axial lumen 108 therein. The proximal end 102 is connected to a smaller diameter tube 110 (see Figure 5A , Figures 6 to 8 ) joint. The distal delivery tube 300 may have a proximal end portion 302, a distal end portion 304, and a compressible portion 306 therebetween. In one example, the compressible portion 306 may be closer to the distal end portion 304, and between the proximal end portion 302 and the compressible portion 306 may be a flexible portion 305. The distal delivery tube 300 forms an axial lumen 308 therein.

[0032] The delivery tube 100, 300 may be made of a biocompatible material such as stainless steel. The tube 100, 300 may typically have a diameter between about 0.010 inches and about 0.018 inches, with a preferred tube having a diameter of about 0.0145 inches. These examples of tube sizes are suitable for delivering and deploying embolic coils to a target location (typically an aneurysm) within the neurovasculature. Tubes 100, 300 of different sizes constructed of other materials may be used for different applications and are within the scope of the present invention.

[0033] The flexible portion 106, 305 allows the delivery tube 100, 300 to bend and flex. This helps track the system 10 through catheters and through the tortuous paths of the human vasculature. The flexible portion 106, 306 can be formed with interfering helical cuts. These cuts allow for clearance to allow for bending, but in one example, do not act as a helical cutting spring. Therefore, bending and flexing are possible, but not compression.

[0034] The compressible portion 306 can be axially adjustable between an elongated state and a compressed state. Preferably, the compressible portion 306 is formed by a spiral cut portion of the tube 300 formed by a laser cutting operation. However, any other arrangement (e.g., a winding wire or a spiral band) that allows axial adjustment is also suitable for use with a separation system according to the present invention. Most preferably, unless otherwise constrained, the compressible portion 306 is in an elongated state when stationary and automatically or elastically returns to the elongated state from the compressed state. The function of the compressible portion 306 is described in more detail herein.

[0035] Figure 3A , Figure 3B and Figure 4An example of a loop 400 is shown. In some embodiments, the loop 400 may be relatively small, having the thickness of a hair, so it may be preferred that the loop 400 is entirely shielded by the distal end 304 of the distal delivery tube 300 to prevent damage from accidental contact. The loop 400 may be a looped elongated wire, such as Figure 3A The loop 400a may also be a single elongated wire having an opening 405, such as Figure 3B . Opening 405 can be formed by loosely bending loop 400a in half. In an alternative example, loop 400b includes a flat band that defines opening 405a at a distal portion, and opening 405b can be in an upward flipped condition suitable for engaging the end of implantable medical device 12. Examples of loops 400, 400a, and 400b can be elastically deformed to an upward flipped condition so that examples of loops 400, 400a, and 400b will return to a substantially flat condition when not otherwise constrained. Loops 400, 400a, and 400b can be formed of any of a variety of materials, including nitinol and stainless steel.

[0036] To load the detachment system 10, the locking member 140 is inserted axially into the lumen 108, lumen 208, and lumen 308 of both tubes 100, tube 300. The distal end 404 of the loop wire 400 is inserted into the distal delivery tube 300 through the anchor portion 310 located on the proximal end 302 of the distal tube 300, and passes through the lumen 308 to the distal end 304. The distal end of the loop wire 404 can then be looped to form an opening 405. The opening 405 passes through the locking portion 18, and the locking member 140 passes through the opening 405 to engage the medical device 12. See FIG. Figure 1A .

[0037] The loop 400 is tightened at the proximal end of the loop 402, and the continuous force F compresses the compressible portion 306. After the medical device 12 is installed on the distal end 304 of the distal tube 300, the amount of compression can be controlled by the amount of force F applied to the proximal end 402 of the loop 400. Figure 2 The installed medical device 12 and distal tube 300 are shown in a compressed state. Once the distal tube 300 is compressed by the appropriate amount, the loop wire 400 is anchor welded 408 to the proximal end 302 (i.e., behind the compressible portion 306) at the wire weld point 406 (between the proximal end 402 and the distal end 404) of the distal delivery tube 300 at or near the anchor portion 310. See FIGS. 5A and Figure 5B Prior to securing the loop 400 in place with the anchor weld 408, the level of compression of the distal delivery tube 300 is adjusted by varying the amount of force F on the loop 400.

[0038] Figure 6 and Figure 7 The combination of the proximal delivery tube 100 and the distal delivery tube 300 is shown. Figure 6 The distal end 104 of the proximal tube 100 is shown pulled toward, and in some examples contacting, the proximal end 302 of the distal tube 300. In this example, the proximal tube 100 and the distal tube 300 do not contact, but leave the weld band 206 as a gap. The two tubes 100, 300 are then circumferentially welded 210 together at the weld band 206 to form an integral device 10.

[0039] Prior to welding the two tubes 100, 300, the locking member 140 (as discussed above) is pulled through the proximal tube lumen 108 to the small tube 110. The locking member 140 is welded 142 to the small tube 110 at the proximal opening 112 in the small tube 110 opposite the proximal end 102 of the proximal tube 100. Figure 8 Shown in.

[0040] Fig. 9An example of a method of assembling a separation system 10 is shown. The method includes forming a compressible portion 306 on a distal tube 300 (step 1000), and forming a flexible portion 106 on a proximal tube 100 (step 1002). Step 1002 may also include forming a flexible portion 305 on the distal tube 300. The compressible portion 306 may be formed by spiral cutting the distal tube 300 or by any other means to form a tube that can be compressed and then quickly returned to the uncompressed state of the tube. The flexible portion 106 of the proximal tube 100 may be interference cut or by any other means to increase the flexibility of the proximal tube 100. Once at least the distal tube 300 is prepared, the medical device 12 may be engaged with the engagement system 140, engagement system 400 (step 1004), and a force F may be applied to the engagement system 140, engagement system 400 to compress the compressible portion 306 (step 1006). It should be noted here that although the examples are presented above using the locking member 140 and the loop 400 as the engagement system, a person of ordinary skill may implement different methods to secure the medical device 12 while still applying a releasable force to the compressible portion 306 to be released when the engagement system 140, 400 is disengaged from the medical device 12. The segment 406 of the engagement system 140, 400 is then engaged to the distal tube 300 to maintain the compressed state of the compressible portion 306 (step 1008). A portion of the engagement system 140, 400 is threaded through the proximal tube 100 (step 1010). The distal tube 300 and the proximal tube 100 are joined together (step 1012). Here, in this example, the ends 104, 302 of the tube 100, 300 are welded together 210. The ends of the engagement system 140 , 400 may then be joined to the proximal end 102 of the proximal tube 100 (step 1014 ) to complete the device 10 .

[0041] Go to FIG. 10A to FIG. 10D , showing the separation of the medical device 12 in more detail. Fig. 10A The engagement system 140, engagement system 400 is shown locked into the locking portion 18 of the medical device 12. An opening 405 through which the loop 400 can be placed is the locking portion 18. When the locking member 140 is passed through the opening 405, the medical device 12 is now secured. A force F was previously applied to place the distal tube 300 in a compressed state. Fig. 10B Locking member 140 is shown being pulled proximally to initiate a release sequence of medical device 12 . Fig. 10CThe moment locking member 140 exits opening 405 and is pulled away from loop 400 is shown. Distal end 404 of loop 400 falls off / returns to its pre-formed shape (as discussed above) and exits locking portion 18. As can be seen, there is now nothing holding medical device 12 to detachment system 10. Fig. 10D The end of the release sequence is shown. Here, the compressible portion 306 has expanded / returned to its original shape and "popped" forward. The elastic force E is imparted to the medical device 12 by the distal end 304 of the distal tube 300 to "push" the medical device 12 away to ensure complete separation and delivery of the medical device 12.

[0042] Fig.11 A distal tube 300 is shown without the medical device 12 but with a compressible portion 306 shortened in axial length to a compressed condition. In particular, a distance "D" is shown by which the distal tube 300 is axially reduced in moving the compressible portion 306 from the elongated condition to the compressed condition. The compression may occur along the axis A. Fig.12 Another view of the medical device 12 at the time of separation is shown. The locking member 140 has been pulled proximally, causing the locking member 140 to separate from the loop 400, allowing the medical device 12 to separate as the distal compression portion 306 expands, and also separating the medical device 12 from the delivery system 10. Arrow "E" represents the elastic force that "pushes" the medical device 12 away from the distal end 304 to ensure complete separation and delivery to the target site in the patient. The elastic force E acts on the axis A of the lumen 308 and "pushes" the medical device 12 along the same axis A (see Figure 8 and Fig.11 ).

[0043] The descriptions contained herein are examples of embodiments of the present invention and are not intended to limit the scope of the present invention in any way. As described herein, the present invention contemplates many variations and modifications of the delivery and release systems of the present invention for vascular occlusive devices, including multiple configurations, multiple stiffness properties, and delivery methods thereof. In addition, there are many possible variations of the configurations of materials and release mechanisms. These modifications will be apparent to those of ordinary skill in the art to which the present invention pertains and are intended to be within the scope of the following claims.

Claims

1. A separation system for delivering an implantable medical device to a target location in a body vessel, the separation system comprising: A generally hollow distal tube, the generally hollow distal tube comprising: proximal end; a distal end; and a compressible portion of the distal tube itself, the compressible portion being axially movable from a compressed condition to an elongated condition between the proximal and distal ends; and a flexible portion between the proximal end and the compressible portion; a generally hollow proximal tube having a proximal end, a distal end, and a flexible portion between the proximal and distal ends; a weld disposed between the proximal end of the distal tube and the distal end of the proximal tube to combine the proximal tube and the distal tube, wherein the proximal end of the distal tube and the distal end of the proximal tube contact each other during welding; an engagement system that engages and deploys the implantable medical device engaged at the distal end of the distal tube; wherein the engagement system moves the compressible portion to the compressed condition when engaging the implantable medical device, and Wherein the engagement system deploys the implantable medical device and releases the compressible portion to the extended condition.

2. The separation system according to claim 1, wherein: The engagement system is removably secured to the proximal end of the distal tube to maintain the compressed condition when engaging the implantable medical device.

3. The separation system according to claim 2, wherein: The engagement system is removably secured to the proximal end of the proximal tube when engaging the implantable medical device.

4. The separation system according to claim 2, wherein: The engagement system comprises: a locking member; and loop, wherein when the loop wire interacts with the locking member to engage the implantable medical device, a force on the loop wire causes the compressible portion to move to the compressed condition, and wherein the loop wire is welded to the proximal end of the distal tube to removably secure the engagement system.

5. The separation system according to claim 4, wherein: The force on the locking member releases the loop, disengaging the implantable medical device and allowing the compressible portion to return to the extended condition.

6. The separation system according to claim 1, wherein: The compressible portion of the distal tube is a helically cut portion of the distal tube.

7. The separation system according to claim 1, wherein: The compressible portion is adapted to deploy the implantable medical device engaged by the engagement system when the compressible portion is moved to the extended condition.

8. The separation system according to claim 1, wherein: The compressible portion of the distal tube is adapted to automatically move to the extended condition when the engagement system is disengaged from the implantable medical device.

9. The separation system according to claim 1, wherein: The compressible portion of the distal tube is adapted to resiliently move to the extended condition when the engagement system is disengaged from the implantable medical device.

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