WO2020231715A1

WO2020231715A1 - Partial vessel occlusion device

Info

Publication number: WO2020231715A1
Application number: PCT/US2020/031751
Authority: WO
Inventors: Landon H. TOMPKINS; Steven Koenig; Gretel MONREAL; Mark SLAUGHTER; Francesca MAYHAUS; Christian BUCKLEY; Adrian Adams; Victoria SAGER
Original assignee: University Of Louisville Research Foundation
Priority date: 2019-05-10
Filing date: 2020-05-07
Publication date: 2020-11-19

Abstract

An occlusion device, comprising an expandable stent configured for insertion into a blood vessel; an expandable balloon arranged at either end of the expandable stent, wherein a diameter of the expandable balloon when inflated is larger than a diameter of the expandable stent and wherein the expandable stent and the expandable balloon together form an inner cavity allowing for blood flow through the device; and a conduit comprising one or more lumens within the inner cavity, wherein the conduit is arranged along a longitudinal axis of the inner cavity is provided. Methods of partially occluding a blood vessel using an occlusion device are also provided.

Description

PARTIAL VESSEL OCCLUSION DEVICE

FIELD OF THE INVENTION

The invention relates to an occlusion device comprising a catheter-based balloon system designed to partially occlude a blood vessel, creating an isolated pocket, while still providing sufficient vessel perfusion.

BACKGROUND OF THE INVENTION

Over the past few decades, there has been a drastic shift in healthcare towards minimally invasive surgical techniques as they may enable more efficient procedures, faster recovery time, reduced tissue damage, and better patient outcomes. However, there are significant disadvantages associated with current methods for these procedures. Often during anastomosis or tissue resection/repair surgeries, clamping is necessary to isolate a section of tissue. Clamping disrupts the native anatomical structure and environment and can result in tissue damage. Open procedures often require large surgical windows to accommodate the array of instruments, which is increased by the addition of clamping tools. Likewise, during endoscopic procedures the use of traditional clamping tools reduces visibility and access to the surgical site. A major complication in anastomosis procedures is leakage due to an inadequate seal, which can result in drainage from the anastomosis site to surrounding tissue, infection, pain, bleeding, and subsequent revision surgeries. In vascular-specific procedures, clamping the vessel restricts blood flow preventing sufficient perfusion to downstream tissues that may lead to serious adverse events, such as ischemia.

Thus, there is a need to develop novel surgical tools and devices to facilitate the advancement of minimally invasive procedures.

SUMMARY

The occlusion device, according to embodiments of the invention, is a device that can partially occlude a blood vessel, such as the ascending aorta, allowing partial perfusion to the rest of the body, while also creating a sealed“pocket” area where the vessel wall can be cored (i.e., a hole is cut out) and opened without the risk of blood leakage. Therefore, a device as described herein can assist with the anastomosis of grafts to the aorta without the need for external clamping or support by cardiopulmonary bypass (CBP). An aspect of the disclosure provides an occlusion device, comprising an expandable stent configured for insertion into a blood vessel; an expandable balloon arranged at either end of the expandable stent, wherein a diameter of the first and second expandable balloon when inflated is larger than a diameter of the expandable stent, wherein the expandable stent and the first and second expandable balloon together form an inner cavity allowing for blood flow through the device, and wherein the first and second expandable balloon are formed from a compliant material that is configured to stretch more than 20% upon inflation; and a conduit comprising one or more lumens within the inner cavity, wherein the conduit is arranged along a longitudinal axis of the inner cavity.

In some embodiments, the compliant material comprises silicone or a silicone and polyurethane hybrid. In some embodiments, the stent is coated with a biocompatible polymer. In some embodiments, the biocompatible polymer is selected from the group consisting of polyurethanes, polyglycolides (PGA), and polylactides (PLA). In some embodiments, the expandable balloon comprises a single balloon extending along the length of the expandable stent and wherein a diameter of a central portion of the expandable balloon is smaller than a diameter of the expandable balloon at either end of the expandable stent when inflated. In some embodiments, the expandable balloon comprises two separate balloons at either end of the expandable stent. In some embodiments, the device further comprises a delivery sheath that at least partially encompasses the expandable stent and balloon and is configured to maintain the expandable stent and expandable balloon in a compressed state.

Another aspect of the disclosure provides a method of partially occluding a blood vessel, comprising inserting an occlusion device as described herein into the blood vessel; and inflating the expandable balloon via the conduit to create a hemostatic pocket within the blood vessel. In some embodiments, the device is inserted into the ascending aorta via the femoral artery. In some embodiments, the inserting step is performed by inserting a guidewire into the blood vessel; and moving the device along the guidewire via the conduit. In some embodiments, the inserting step comprises removing the expandable stent and expandable balloon from the delivery sheath within the blood vessel.

Additional features and advantages of the invention will be set forth in the description below, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention can be realized and attained by the exemplary structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1. An occlusion device according to some embodiments of the disclosure.

Figures 2A-B. Cross-section view of an occlusion device according to some embodiments of the disclosure having a conduit arranged on an (A) inner or (B) outer surface of the blood flow lumen.

Figures 3A-E. (A), (E) Side view, (B) distal end view, and (C), (D) proximal end view of an occlusion device according to some embodiments of the disclosure.

Figures 4A-B. (A) Full view and (B) close-up view of a conduit according to some embodiments of the disclosure.

Figures 5A-B. (A) Full view and (B) close-up view of a conduit according to some embodiments of the disclosure.

Figures 6A-B. (A) Side view and (B) cross-section view of a delivery sheath according to some embodiments of the disclosure.

Figures 7A-B. (A) Proximal end view and (B) distal end view of an occlusion device connected to branched tubing via a multi-lumen conduit.

Figures 8A-D. Exemplary method for inserting and retracting an occlusion device. (A) A loaded sheath is inserted over the guidewire. (B) The stent is removed from the delivery sheath by advancing the conduit. (C) The balloon is inflated to create a hemostatic pocket. (D) The deflated balloon and stent are retracted back into the delivery sheath by retracting the conduit.

Figure 9. Illustration of an exemplary occlusion device deployed in the ascending aortic arch.

Figure 10. An occlusion device according to some embodiments of the disclosure comprising a single balloon extending along the length of the expandable stent.

Figures 11A-F. Exemplary method for inserting and retracting an occlusion device. (A) A loaded sheath is inserted over the guidewire. (B) The stent is removed from the delivery sheath to expose the entire balloon-stent structure. (C) The stent-structure is expanded. (D) The balloons are inflated to create a hemostatic region between the balloons. (E) The balloons are deflated after device usage. (F) The deflated balloon and stent are collapsed and retracted back into the delivery sheath.

DETAILED DESCRIPTION

Embodiments of the disclosure provide a minimally-invasive medical device that functions as a partial occluder to create a hemostatic environment within a blood vessel while maintaining sufficient perfusion. The occlusion device may be used to support an array of less invasive surgical approaches for cardiovascular, gastrointestinal, bariatric, urinary tract, and trauma procedures, including end-to-side anastomoses, tissue resection, tissue repair, and/or insertion of other medical device implants.

With reference to Figures 1-6, a device 100 as described herein may be comprised of a balloon-stent structure, a conduit 140, and a delivery sheath 150. The balloon-stent structure comprises one or more compliant balloons 120 positioned on the ends of a self-expanding and collapsible stent 110 having a tubular shape which serves as the perfusion lumen and means of occlusion. When the balloons 120 are inflated, a seal is formed with the surrounding tissue wall, creating a hemostatic environment between the balloons 120. The conduit 140 and delivery sheath 150 assist in device placement, deployment, and retraction.

Expandable stents compatible with the present disclosure are known in the art. The stent 110 is configured for insertion into a blood vessel and together with the expandable balloon 120 forms an inner cavity 130 allowing for blood flow through the device. The stent 110 may be self expanding and collapsible to allow for device introduction/removal through the femoral artery, and to maximize the diameter of the blood flow lumen once located in the aorta. Maximizing the blood flow lumen diameter is important for optimal perfusion. In general, suitable stents may be formed from a metal or plastic mesh. In some embodiments, the stent is formed from nitinol, various metal alloys, or other biocompatible materials with shape memory capabilities.

In some embodiments, the stent 110 is coated with a biocompatible polymer. Suitable biocompatible polymers include, but are not limited to, polyurethanes, polyglycolides (PGA), polylactides (PLA), and combinations thereof.

The expandable balloon 120 located at either end of the stent 100 may be formed from a compliant (i.e. non-rigid) material that is configured to stretch more than 20% upon inflation, e.g. more than 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or more. The use of a compliant material provides a better seal to the aortic wall and allows the device to adapt to anatomic variances. Suitable compliant materials include, but are not limited to, silicone, a silicone/polyurethane hybrid, nylon, Pebax, polyethylene, polyurethane, and combinations thereof.

The expandable balloon 120 can be inflated, e.g. via a syringe, with an appropriate fluid such as air or saline. The expandable balloon 120 can be deflated, e.g. via a syringe, by withdrawing the fluid.

In some embodiments, the expandable balloon 120 comprises two separate balloons at either end of the expandable stent (Figures 7A-B). The incorporation of separately affixed balloons allows for the device to have more stability due to the rigidity of the stent holding the balloons together. Independently inflating the balloons allows for the device to adapt to various anatomical structures (i.e., diameter differences of the blood vessel), providing better anchoring and reducing the possibility of device shift or dislodgment. The balloon structures may form a funnel shape to facilitate blood flow through the lumen.

In some embodiments, the expandable balloon 120 comprises a single balloon extending along the length of the expandable stent and a diameter of a central portion of the expandable balloon is smaller than a diameter of the expandable balloon at either end of the expandable stent when inflated (Figure 10).

The conduit 140 is arranged along a longitudinal axis of the inner cavity of the device (Figures 1-3 and 7). In some embodiments, the conduit 140 is arranged on an outer surface of the inner cavity (Figure 2B and Figures 3D-E). The conduit 140 comprises one or more lumens and is used as a means to advance and position of the device. The conduit may span the entirety of the balloon-stent structure and extend outside of the device insertion location where the tubing can be accessed. In some embodiments, the conduit may house multiple smaller lumens, e.g. at least 2, 3, 4, 5, 6, or more which may be used, e.g., for guidewire insertion, balloon inflation, patient pressure monitoring (e.g., monitoring of aortic/vessel pressure via a fluid line and transducer external to the patient), and dye injection for viewing of the device and hemostatic pocket under fluoroscopy. Each smaller lumen may branch off as independent tubing on the proximal end of the conduit (Figures 7A-7B). In some embodiments, the smaller lumens are separate channels (Figures 4A-B). In some embodiments, the smaller lumens are interconnected (Figures 5A-B). Suitable materials that may form the multi-lumen conduit include, but are not limited to, medical-grade silicone, polyurethane, polyethylene, polyvinyl chloride, polytetrafluoroethylene, and nylon. With reference to Figures 6A-B and Figure 8A, in some embodiments, the device may include a delivery sheath 150 that may serve as a means to deploy and retract the balloon-stent structure. The delivery sheath 150 at least partially encompasses the expandable stent and balloon and is configured to maintain the expandable stent and expandable balloon in a compressed or non-expanded, non-inflated state. With reference to Figures 8B-D and Figure 9, in some embodiments, the delivery sheath 150 may be used to insert the device through the femoral artery. After being advanced to the abdominal aorta, the balloon-stent structure may be deployed from the delivery sheath (Figure 8B). After the conclusion of the procedure, the balloon-stent structure may then be retracted back into the abdominal aorta, where it is then collapsed into the delivery sheath for removal through the femoral artery (Figure 8D). In some embodiments, the delivery sheath comprises a tapered internal diameter (fillet) on an inner surface of the sheath to facilitate balloon- stent collapse and retraction into the sheath. Suitable materials that may form the delivery sheath include, but are not limited to, medical-grade silicone, polyurethane, polyethylene, polyvinyl chloride, polytetrafluoroethylene, and nylon.

The size of the device as described herein may be configured to accommodate various patient vessel sizes, ages, or surgical procedures. Depending on the size of the blood vessel, the balloons should be appropriately sized such that upon inflation, a seal is formed between the outer edges of the balloon and the inner wall of the blood vessel. The diameter of the stent is smaller than the diameter of the balloons such that when the balloons come in contact with the inside wall of the blood vessel, an area of hemostasis is created between the outer wall of the stent and the inner wall of the blood vessel. The blood will continue to flow through the stent. However, the blood trapped in the area of hemostasis will be static. The length of the stent may be varied to accommodate different types of procedures. For example, in one embodiment, the length of the stent is sufficient to provide a working area to perform a left ventricular assist device (LVAD) outflow graft anastomosis.

Embodiments of the disclosure provide methods of partially occluding a blood vessel using a device as described herein. In some embodiments, the steps comprise inserting the occlusion device into the blood vessel; and inflating the expandable balloon via the conduit to create a hemostatic pocket within the blood vessel. In some embodiments, the inserting step is performed by inserting a guidewire into the blood vessel; and moving the device along the guidewire via the conduit. In some embodiments, the inserting step comprises removing the expandable stent and expandable balloon from the delivery sheath within the blood vessel.

A device as described herein eliminates the need for clamping as it provides a static region for anastomosis, tissue resection, and/or tissue repair. Since the device is catheter-based, there is no requirement to increase the surgical window to accommodate cross-clamps. In endoscopic procedures, visualization and access is maximized as the clamping tools used to seal the area do not compete for space needed for any other surgical instruments. The device also maintains the natural shape of the vessel during occlusion compared to previous clamping methods, resulting in wall stresses that may more closely resemble normal vessel anatomy.

Surgical and clinical applications of the device include, but are not limited to, cardiovascular, gastrointestinal, bariatric, urinary tract, and trauma procedures, including LVAD outflow graft anastomosis, end-to-side anastomoses, tissue resection, tissue repair (e.g. in trauma cases), coronary artery bypass grafting (CABG), general angioplasty procedures, and/or other medical device implant procedures or procedures in which the creation of a hemostatic pocket would be beneficial. In some embodiments, the device is used for attachment of any tubular graft to a hollow organ allowing blood flow. In some embodiments, the device is used for minimally- invasive, laparoscopic, endoscopic, and/or natural orifice transluminal endoscopic surgeries. In some embodiments, the device is used as a axillary or subclavian vascular access port to facilitate the introduction of intra-aortic balloon pumps and other MCS devices intended to be placed within the aorta. In some embodiments, the device is used to assist in a surgical procedure for providing vascular access for dialysis and chemotherapy.

LVADs are frequently utilized due to long-term viability and durability. However, LVAD outflow graft attachment methods require cross-clamping the aorta and/or cardiopulmonary bypass (CPB), which may be associated with potential risk of complications and/or adverse events. Using a device as disclosed herein to create a hemostatic pocket allows for coring of the vessel wall without cross-clamping the aorta, and provides adequate perfusion eliminating the need for CPB. The two distinct advantages (hemostatic seal and perfusion) enable less invasive surgical procedures while also reducing patient risk factors. In some embodiments, the device as described herein is used in conjunction with a sutureless quick connect device, such as a Uniti™ device, which attaches the outflow graft to the aorta. The device as described herein may occlude a portion of the ascending aorta at the Uniti™ device implantation site. Once the graft and Uniti™ device are in place, the balloon can be deflated and retracted, returning the aorta to full perfusion. An exemplary method of the disclosure may comprise the following steps (Figure 11):

• Step 1: Femoral artery access is gained, and a guidewire is inserted through the femoral artery and navigated through the abdominal and descending aorta until reaching the ascending aorta.

• Step 2: Loaded sheath is inserted over the guidewire (via the guidewire catheter tube) and advanced retrograde to the abdominal aorta. Loaded sheath contains collapsed balloon- stent structure and deflated balloons (Figure 11A).

• Step 3 : Advance the balloon-stent structure past the delivery sheath by advancing the multi lumen conduit (Figure 11B). Once completely exposed from the delivery sheath, the stent will be fully expanded for use (Figure 11C). The delivery sheath will remain in position in the abdominal aorta until retraction.

• Step 4: Advance the balloon-stent structure to the desired location in the ascending aorta.

• Step 5: Inflate the balloons with saline using a syringe attached to the inflation lumen. This creates the hemostatic pocket for anastomosis (Figure 1 ID).

• Step 6: Deflate balloons using syringe once procedure is completed (Figure 1 IE).

• Step 7: Retract balloon-stent structure back into delivery sheath in the abdominal aorta by retracting the multi-lumen conduit (Figure 11F).

• Step 8: Remove loaded delivery sheath from patient through femoral artery.

It is to be understood that this invention is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention. It is noted that, as used herein and in the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as "solely," "only" and the like in connection with the recitation of claim elements, or use of a "negative" limitation.

As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. Any recited method can be carried out in the order of events recited or in any other order which is logically possible.

While the invention has been described in terms of its preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims. Accordingly, the present invention should not be limited to the embodiments as described above, but should further include all modifications and equivalents thereof within the spirit and scope of the description provided herein.

Claims

CLAIMS We claim:

1. An occlusion device, comprising:

an expandable stent configured for insertion into a blood vessel;

a first and second expandable balloon arranged at either end of the expandable stent, wherein a diameter of the first and second expandable balloon when inflated is larger than a diameter of the expandable stent, wherein the expandable stent and the first and second expandable balloon together form an inner cavity allowing for blood flow through the device, and wherein the first and second expandable balloon are formed from a compliant material that is configured to stretch more than 20% upon inflation; and

a conduit comprising one or more lumens within the inner cavity, wherein the conduit is arranged along a longitudinal axis of the inner cavity.

2. The occlusion device of claim 1, wherein the compliant material comprises silicone or a silicone and polyurethane hybrid.

3. The occlusion device of claim 1, wherein the stent is coated with a biocompatible polymer.

4. The occlusion device of claim 3, wherein the biocompatible polymer is selected from the group consisting of polyurethanes, polyglycolides (PGA), and polylactides (PLA).

5. The occlusion device of claim 1, wherein the expandable balloon comprises a single balloon extending along the length of the expandable stent and wherein a diameter of a central portion of the expandable balloon is smaller than a diameter of the expandable balloon at either end of the expandable stent when inflated.

6. The occlusion device of claim 1, wherein the expandable balloon comprises two separate balloons at either end of the expandable stent.

7. The occlusion device of claim 1, further comprising a delivery sheath that at least partially encompasses the expandable stent and expandable balloon and is configured to maintain the expandable stent and expandable balloon in a compressed state.

8. A method of partially occluding a blood vessel, comprising:

inserting an occlusion device according to claim 1 into the blood vessel; and

inflating the expandable balloon via the conduit to create a hemostatic pocket within the blood vessel.

9. The method of claim 8, wherein the device is inserted into the ascending aorta via the femoral artery.

10. The method of claim 8, wherein the inserting step is performed by

inserting a guidewire into the blood vessel; and

moving the device along the guidewire via the conduit.

11. The method of claim 8, wherein the device further comprises a delivery sheath that at least partially encompasses the occlusion device and is configured to maintain the expandable stent and expandable balloon in a compressed state and wherein the inserting step comprises removing the expandable stent and expandable balloon from the delivery sheath within the blood vessel.

12. The method of claim 8, wherein the compliant material comprises silicone or a silicone and polyurethane hybrid.

13. The method of claim 8, wherein the stent is coated with a biocompatible polymer.

14. The method of claim 13, wherein the biocompatible polymer is selected from the group consisting of polyurethanes, polyglycolides (PGA), and polylactides (PLA).

15. The method of claim 8, wherein the expandable balloon comprises a single balloon extending along the length of the expandable stent and wherein a diameter of a central portion of the expandable balloon is smaller than a diameter of the expandable balloon at either end of the expandable stent when inflated.

16. The method of claim 8, wherein the expandable balloon comprises two separate balloons at either end of the expandable stent.