Blockstent device and methods of use

What is disclosed is a medical device comprising a compressed, cylindrical or oblong, thin-walled, expandable metal structure (a “blockstent”) and a flexible, elongated device (a “delivery catheter”) to position the compressed blockstent into the lumen of a blood vessel segment to be treated, and methods of use for occlusion of treated blood vessel segments. A blockstent can be made with ductile metals such as gold, platinum, or silver such that the blockstent will conform to the shape of the lumen of the treated blood vessel segment during expansion and allow for the shape of the blockstent to be permanently changed by the application of an external force. The surface of the blockstent can be configured to promote local thrombus on the external surface of the blockstent and to promote the growth of tissue into the wall of the blockstent in order to occlude the treated blood vessel and fix the blockstent in place. The wall of the blockstent can also be configured to release drugs or pharmacologically active molecules such as those that promote thrombosis, cell proliferation, extracellular matrix deposition to promote this thrombus formation and tissue growth.

FIELD OF THE PRESENT DISCLOSURE

The present disclosure relates to a medical device comprising a blockstent and a delivery catheter for the treatment of blood vessel segments of the vascular system. The present disclosure also relates to various forms of blockstents and delivery catheters, and methods of their manufacture. The present disclosure further relates to methods of occluding blood vessel segments using the various medical devices, whereby the blockstent ultimately remains in the blood vessel segment. Blockstents are cylindrical, thin-walled expandable metal structures comprised of a stent-like device and designed to fill the lumen of a blood vessel segment. Blockstents are configured for: attachment to delivery catheters, compression, advancement through the vascular system, expansion within lumen of blood vessel segments, and then separation from delivery catheters. Delivery catheters of various sizes, shapes, materials, and configurations can be used to position a compressed blockstent in a blood vessel segment and expand the blockstent in the blood vessel by the passage of fluids or solids through the delivery catheter and into the central void or space of the blockstent. Further, the invention relates to components for, and methods of, attaching the blockstent to the delivery catheter, as well as components for, and methods of, separating the expanded blockstent from the delivery catheter, such that the blockstent remains in place in an expanded state within the blood vessel while the delivery catheter is removed from the body.

BACKGROUND OF THE PRESENT DISCLOSURE

In certain clinical situations, patients can benefit from the occlusion of certain artery or vein segments through endovascular means. Clinical settings where endovascular vessel occlusion is beneficial include reducing bleeding from an injured vessel, reducing blood flow to tumors, and rerouting the path of blood in the vascular system for other purposes. Alternatively, minimally invasive, catheter-based, endovascular treatments have been developed to occlude blood vessel segments. Endovascular medical devices for blood vessel occlusion include balloon catheters wherein the balloon can be inflated to fill the lumen of a blood vessel segment and detached from the catheter. There are two major drawbacks to the use of detachable balloon catheters for blood vessel occlusion. First, the balloons are made of polymers that generally resist tissue incorporation that limits fixation of the devices where they are placed. Second, the balloons are configured with elastic walls which are expanded with pressurization and valves designed to maintain that pressure after detachment. Unfortunately, there is a substantial rate of balloon and valve failure, resulting in deflation. Without tissue incorporation, balloon deflation can lead to balloon migration and occlusion of non-target vessel segments. Endovascular medical devices for blood vessel occlusion include metal coils that are used to fill a portion of the lumen of a blood vessel segment to induce thrombosis and occlusion of the blood vessel segment. There are several major drawbacks to the use of metal coils and basket structures for blood vessel occlusion. First, numerous coils are usually required to occlude the blood vessel segment, resulting in higher costs and longer treatment times. Second, coil placement is difficult to control, often resulting in coil placement in non-target vessel segments. Third, coils only partially fill the blood vessel. The accumulation of thrombus and scar tissue is required to occlude the blood vessel, a process that takes weeks to occur and is sometimes incomplete, often resulting in incomplete occlusion or recanalization and a failed treatment. More recently, endovascular medical devices for blood vessel occlusion have been developed that include basket structures that are used to fill a portion of the lumen of a blood vessel segment to induce thrombosis and occlusion of the blood vessel segment. Although only a single basket structure is usually required to occlude a blood vessel segment, and the devices are generally easier to control, these devices only partially fill the blood vessel and require the accumulation of thrombus and scar tissue to occlude the blood vessel. As with coils, this process that takes weeks to occur and is sometimes incomplete, often resulting in incomplete occlusion or recanalization and a failed treatment.

Therefore, there remains a need for catheter-based medical devices, systems, and methods for the occlusion of blood vessel segments that are simple to perform, result in a rapid, controlled, and complete occlusion, have a low risk of recanalization, device migration, or other complications, and can be purchased at a reasonable cost.

SUMMARY OF THE PRESENT DISCLOSURE

The present invention relates to a medical device for the occlusion, or blockage, of blood vessel segments—including arteries and veins, and other vascular conduits. The medical devices comprise a blockstent, a delivery catheter for delivering and expanding the blockstent, and a component for separating the expanded blockstent and the delivery catheter. The invention further relates to an expanded blockstent left in the lumen of a blood vessel segment. Additionally, the invention includes various forms of blockstents, delivery catheters, and components for separation. Further, the invention includes systems and methods relating to the use of the medical devices, as well as kits comprising medical devices and instructions for use. The invention also includes methods of manufacturing blockstents, delivery catheters, and components for separation.

The walls of blockstents can be formed from a variety of expandable, rigid materials, preferably metals. The metal used to make the wall of a blockstent can be selected from the group consisting of gold, platinum, silver, titanium, vanadium, aluminum, nickel, tantalum, zirconium, chromium, silver, gold, silicon, magnesium, niobium, scandium, platinum, cobalt, palladium, manganese, molybdenum, alloys thereof, and/or combinations thereof. Other metals can be used so long as they are safe to use as an implanted medical device, can be formed into thin walls, and can be expanded from a compressed state and remain expanded in the body, holding their shape under typical conditions. Preferably, the blockstent is made of a ductile metal such as gold, platinum, silver, alloys thereof, and/or combinations thereof. In a fully expanded form, the blockstent can be configured in a variety of sizes and shapes, depending on the size and shape of the blood vessel to be treated, with preferable forms including a cylinder with rounded, hemispherical, or flat ends. Available shapes include, but are not limited to, cylindrical or oblong. Preferably, the blockstent can have an expanded diameter ranging from about 2 mm to about 30 mm. The oblong blockstent can have an expanded length of between about 5 mm to about 60 mm. The blockstent wall has a width, or thickness ranging from about 3 μm to about 180 μm. Such width allows for compression into a small volume and facilitates passage through blood vessels and catheters. For example, blockstents can be folded and compressed to a diameter small enough to pass through 3Fr to 12Fr catheters, such that small, medium, and large diameter blood vessels can be treated, or maneuvered through small vessels, including but not limited to cerebral arteries.

The wall of the blockstent can be uniform or variable, with the thickness changing at different locations on the blockstent. In some blockstent embodiments, the wall of the region near the attachment to the delivery catheter is thicker than the main body of the blockstent, while in other embodiments this region is thinner. In other embodiments, the wall of the blockstent contains an external layer that is porous. This porosity generally can be uniformly distributed, or can be applied only in certain regions, or in a pattern on the surface. In certain embodiments, a blockstent can have a plurality of pores extending through the entire wall.

In other embodiments, the external surface of the wall of the blockstent contains, which in certain instances act to reduce blockstent migration after expansion. These projections may be macroscopic, such as with the hooks or bards seen on other implanted cardiovascular medical devices such as caval filters. For example, a plurality of projections, such as barbs and hooks, can be located on the exterior layer to anchor the blockstent to the surrounding tissue. In a further embodiment, these projections comprise an expansile metal, such as nitinol or fibers. For some embodiments, these projections are microscopic, ranging in length from 0.01 μm to about 157 μm. In other embodiments, these projections are branching.

The surface of the blockstent wall can be configured to increase local thrombus formation and tissue growth into the blockstent wall in order to secure the blockstent in place and reduce the risk of blockstent migration. The wall of the blockstent can further be configured to release solutions that can include drugs, pharmacologically active molecules, or pharmacologic compositions, such as those that would increase the formation of local thrombus, stimulate cell proliferation or the production of extracellular matrix, or increase the rate or extent of tissue growth, such as tissue growth into pores, or around projections, of the wall of the blockstent.

In one embodiment, the blockstent has an exterior layer located on the exterior surface of the wall. The exterior layer may be made from the same materials as the central layer or wall, or can be made of different materials. The exterior layer may be comprised gold, platinum, silver, alloys thereof, or combinations thereof. The exterior layer may also be comprised of polymer, plastic, latex, rubber, an elastomer, fiber material, and combinations thereof. The exterior layer can have a thickness ranging between about 1 μm to about 59 μm.

In one embodiment, the exterior layer has a porous construction. For embodiments with a porous exterior layer, the exterior layer of the blockstent wall can have a plurality of pores ranging in diameter from about 0.01 μm to about 100 μm. The pores allow tissue to grow into the wall of the blockstent. The pores can be uniformly distributed, or can be applied only in certain regions, or in a pattern on the surface. In another embodiment the exterior layer comprises a plurality of projections. These projections can range in length from about 0.01 μm to about 157 μm. In other embodiments, these projections are branching. The projections allow tissue to grow around portions of the wall of the blockstent. The projections can be uniformly distributed, or can be applied only in certain regions, or in a pattern on the surface.

In one embodiment, the porous exterior layer can be configured to release solutions such as drugs, pharmacologically active molecules, pharmacologic compositions, or other compositions that increase the local formation of thrombus rate, or stimulate cell proliferation, extracellular matrix formation, or tissue growth into the pores or around projections of the blockstent wall. Examples of such substances include thrombin, platelet-derived growth factor, Ethiodol®, Sotradecol®, and combinations thereof, and can include both solutions and suspensions. The porous exterior layer can be comprised of any porous material, including metal that can hold fluid or solid material, including drugs, pharmacologically active molecules, or pharmacologic compositions, or any material that promotes thrombosis, cell proliferation, extracellular matrix productions or tissue growth.

Alternatively, the exterior layer can be more smooth, with limited porosity or projections, such as with a polished metal surface. In one embodiment, portions of the exterior layer can be smooth, while other portions can be porous or contain projections. In one embodiment, this surface variation can have a pattern.

In one embodiment, the blockstent has an interior layer located on the interior surface of the central layer or wall. The interior layer may be made from the same materials as the central layer, or can be made of different materials. The interior layer may be comprised gold, platinum, silver, alloys thereof, or combinations thereof. The interior layer may also be comprised of polymer, plastic, latex, rubber, an elastomer, fiber material, and combinations thereof. The interior layer can have a thickness ranging between about 0.1 μm to about 59 μm. Preferably, the interior layer may be an elastomeric coating that strengthens the wall, reduces the leaking of fluid from the blockstent during expansion, or facilitates folding, compression, or expansion of the blockstent.

In another embodiment, the blockstent may include two or more metal regions joined by a flexible polymer and/or elastomer joint. The joint allows for better maneuverability and increased trackability as the blockstent is advanced to the desired location. In other embodiments, the blockstent may include three or more metallic regions that are joined through two or more flexible joints.

The blockstent wall defines an opening that allows for the passage of fluid. An attachment between the blockstent and delivery device is formed whereby the void of the blockstent defined by the inner surface of the wall can be joined in fluid communication with the lumen of a hollow cylindrical member of the delivery device which is configured to allow for the proximal end of the lumen to accept a fluid source and for fluid to pass from the fluid source, through the lumen of the hollow cylindrical member of the delivery device, and into the void of the compressed blockstent, resulting in expansion of the blockstent.

In one embodiment, the fluid used to expand the blockstent is water or a saline solution. In another embodiment, the fluid is a solution of radiopaque contrast material. In another embodiment, solids can be used to expand the blockstent, including solids used in combination with fluids. In one embodiment, the solids used to expand the blockstent, or to reduce subsequent compression of the expanded blockstent, are selected from the group of metallic or polymeric coils or wires, metallic or polymeric expansile structures, beads, balls, microspheres, radially expansive materials, support structures, or combinations thereof. In another embodiment, the fluid that is used to expand the blockstent can contain drugs or pharmacologically active molecules, such as those that catalyze the formation of thrombus, including thrombin. Fluid, as defined, can be a gas, liquid, or combination thereof.

The blockstent wall defines an opening that allows for the passage of fluid. An attachment between the blockstent and delivery device is formed whereby the two devices are in fluid communication. The opening defined by the wall of the blockstent can have a diameter ranging between about 0.25 mm and about 5 mm. Optionally, the blockstent has a neck integral with the wall, whereby the neck defines an opening that can extend away from the main body of the blockstent, such as with an external neck, or may extend into the void of the blockstent, such as with an internal neck. The neck of the blockstent may be configured to remain open at the end of the procedure, or may be configured to be sealed prior to the end of the procedure.

The present invention also includes a delivery device for positioning and expanding the blockstent. Various configurations of delivery device can be used to advance the blockstent to the desired location and expand the blockstent. Preferably, the delivery device is a delivery catheter. The delivery catheter includes one or more hollow cylindrical members that define one or more lumens. The delivery catheter can be constructed as a single-lumen catheter, wherein the single cylindrical member is dimensioned to deliver the blockstent to a desired location and deliver fluid from a fluid source at the proximal end into the central void of the blockstent at the distal end. When a single cylindrical member with a single lumen is used, generally the medical device is advanced into position through the lumen of a separate guide catheter, which acts to guide the blockstent portion of the medical device to the desired location in the lumen of the blood vessel. Once at the desired location, the blockstent can be expanded and separated from the delivery catheter so that it can remain in the blood vessel while the delivery catheter is removed. For this single lumen embodiment, the catheter does not include a cylindrical member that defines a lumen that is dimensioned to allow for the passage of a guidance member, or guide wire. The wall of the delivery catheter can be comprised of standard catheter materials including a plastic or polymer material such as polyurethane. Further, the wall of the delivery catheter can be additionally comprised of metal reinforcement, such as metal reinforcement that is wound in a coil or braid, or some combination of these materials, as described.

In one embodiment, the delivery device comprises a single lumen delivery catheter wherein the distal end of the delivery catheter is configured to enable a fluid connection between a lumen of the delivery catheter and the central void of the blockstent. When the blockstent is compressed, this delivery catheter can advance the compressed blockstent through a guide catheter and into the lumen of the blood vessel. The delivery catheter also optionally comprises a wire or obturator of a size that fills at least a portion of the lumen of the catheter. The wire or obturator can further comprise a handle to assist removal of the wire or obturator and enable the passage of fluid through the delivery catheter and into the central void of the blockstent to expand the blockstent.

The delivery catheter can also be constructed as a double-lumen catheter, wherein the first cylindrical member is dimensioned to deliver fluid from the fluid source into the central void of the blockstent and a second cylindrical member is dimensioned to pass over the guidance member, which acts to guide the medical device to the desired location in the lumen of the blood vessel. The guidance member is typically a flexible guide wire that may have a soft, flexible tip in a straight, angled, or j-shaped tip configuration.

In a particular embodiment, the delivery catheter includes a hollow cylindrical member that defines a lumen. The cylindrical member has a proximal end that is attached or can be attached to a fluid source. The cylindrical member comprises polyurethane, with a reinforcement of metal in the form of a coil or braid, and a wall thickness between about 0.05 mm and 0.25 mm. The defined lumen has a diameter between about 0.4 mm and 1.0 mm. A wire comprised of nitinol or fibers with a diameter between about 0.3 mm and 0.95 mm is placed in the lumen. A cylindrical blockstent with a wall and flattened ends composed of gold with a wall thickness of 15 μm, an expanded diameter of 4 mm, and an expanded length of 6 mm is attached to the distal end of the delivery catheter by friction in a manner that allows for the formation of a fluid connection between the lumen of the cylindrical member and the central void of the blockstent. Alternatively, The blockstent can have rounded ends. The blockstent may be folded and compressed into a cylindrical shape at the tip of the delivery catheter.

Various methods can be used to compress the blockstent and enable it to travel through a hollow cylindrical member, or lumen, of a separate guide catheter or through small diameter blood vessels. In one embodiment, the blockstent is folded to form one or more pleats prior to or after attaching the blockstent to the delivery catheter, and the pleats are rolled and compressed, similar to the folding of a non-compliant angioplasty balloon. In another embodiment, the blockstent is flattened into a planar shape, and rolled into a cylindrical shape. In another embodiment, the blockstent is compressed into a compact spherical shape. In another embodiment, the blockstent is folded and compressed into a manner similar to origami. In certain embodiments, the blockstent may be folded and wrapped around the shaft of the delivery catheter.

The blockstent may be attached to the delivery catheter using a variety of materials, components, systems, and methods. The blockstent can be attached to the delivery catheter in a manner wherein the size and shape of the distal end of the delivery catheter and the size and shape of the opening in the blockstent wall are matched so that a friction fit is formed between blockstent and the delivery catheter. In an embodiment of a friction fit, an elastic sleeve or wrap can be placed around the neck of the blockstent and used to further hold the blockstent and the delivery catheter together. In another embodiment of a friction fit, a vacuum can be formed in the catheter to further hold the blockstent and the delivery catheter together. The blockstent can be attached to the delivery catheter using an adhesive, or glue. The blockstent can be attached to the delivery catheter using a weld, or solder. The blockstent can be attached to the delivery catheter by a fitting of mechanical parts on the blockstent and the delivery catheter, such as with a clamp that can be released with a wire, polymer strand, filament, thread, or string that can be loosend or removed.

After expansion of the blockstent in the lumen of a blood vessel segment, the blockstent may be separated from the delivery catheter using a variety of materials, components, devices, systems, and methods. For example, the expanded blockstent may be separated from the delivery catheter using components of the medical device, using a separate and distinct medical device, or combinations thereof. The blockstent may be separated from the delivery catheter using a variety of methods including physical methods, mechanical methods, electrical methods, thermal methods, chemical methods, hydraulic methods, sonic methods, and combinations thereof.

By way of example and not limitation, for electrical methods, the medical device can be configured such that electrolysis can be used to dissolve a metal weld or solder between the blockstent and the delivery catheter, or used to dissolve a portion of the metal blockstent itself. In certain embodiments, an elongated, insulated electrolysis wire or insulated conductor wire can carry an electrical current from the proximal end of the delivery catheter to the distal end of the delivery catheter where it may be electrically coupled to the weld or solder, or to the blockstent itself. A portion of the weld or solder, or a portion of the blockstent itself may lack insulation such that the electrical current traveling through the insulated electrolysis wire or insulated conductor wire will dissolve the portion of the weld, solder, or the portion of the blockstent that lacks insulation, resulting in separation of the blockstent from the delivery catheter. The blockstent can have a neck for example, that can be coated on the inner wall, outer wall, or both, wherein a strip of conductive material left is left exposed, uncoated, or uninsulated and whereby the wire is in electrical contact with the blockstent. During the electrolysis process may separate a portion of the weld material or a portion of the wall of the blockstent into oppositely charged ions. By way of example and not limitation, for mechanical methods, the medical device can be configured such that the delivery catheter is physically separated from the blockstent by cutting or tearing a portion of the blockstent using a flexible loop of wire, polymer strand, filament, string, thread, or snare, or by using one or more blades. A mechanical separation may also occur where the delivery catheter is physically separated from the blockstent by a disengagement of mechanically mated parts, such as a clamp, or by removing a wire, polymer strand, filament, string, or thread that holds the blockstent and the delivery catheter together. By way of example and not limitation, for thermal methods, the medical device can be configured such that an adhesive bond is warmed, causing the adhesive to melt and allowing for separation of the expanded blockstent and the delivery catheter by subsequently pulling them apart. Separation of an expanded blockstent and a delivery catheter may also occur by applying a hydraulic force, by dissolving a bonding medium with a salt, an acid or base, or a chemical, or by applying sound waves such as focused or pulsed ultrasound waves. Another method, involves perforating the neck prior to usage, so that upon expansion the blockstent can be separated from the delivery catheter by pulling them apart at the line of perforation.

By way of example and not limitation, for attachment by friction bonding, the expanded blockstent and the delivery catheter can simply be pulled apart. By way of example and not limitation, for attachment by an adhesive or glue, the blockstent may be separated from the delivery catheter by mechanical mechanism such as by cutting or tearing a portion of the blockstent or the distal portion of the catheter, by electrolysis of a weld, solder, or a portion of the blockstent, or by warming the adhesive bond, causing it to flow. By way of example and not limitation, for attachment by a weld or solder, the blockstent may be separated from the delivery catheter by electrolysis of a weld, solder, or a portion of the blockstent, or by a mechanical mechanism such as by cutting or tearing a portion of the blockstent or the distal portion of the catheter.

The shape and size of the blockstent may be modified after expansion. For example, prior to separation from the delivery catheter, withdrawing fluid from the void of the blockstent can reduce the size of the blockstent. Also prior to separation, a force can be applied to the blockstent through the delivery catheter by advancing the delivery catheter forward or pulling the delivery catheter back, thus modifying the shape of the blockstent. After separation, an external force can be applied to the blockstent by inflating the balloon portion of a balloon catheter adjacent to the blockstent to modify the shape of the blockstent or push a portion of the blockstent towards a blood vessel. In certain embodiments, this can reduce the amount of blockstent that protrudes from the blood vessel into the lumen of the adjacent parent, or native, vessel. Also, the opening of the expanded blockstent can be sealed through a variety of methods, or left open.

The present invention also relates to a method of occluding a segment of blood vessel with a medical device comprising the blockstent and delivery catheter. The method includes the steps of positioning the compressed blockstent in the lumen of the blood vessel segment to be treated using a delivery catheter, expanding the blockstent by passing fluid through the delivery catheter into the void of the blockstent, separating the delivery catheter from the expanded blockstent and, removing the delivery catheter while leaving the blockstent in an expanded state within the blood vessel segment.

One method for placement of an expanded blockstent within a blood vessel segment includes the steps of accessing the vasculature with a needle, inserting a guide wire through the needle, removing the needle, and optionally, inserting a vascular sheath into the blood vessel. The method also includes the steps of advancing a guide catheter over a guide wire until the tip of the guide catheter is within or near the lumen of the blood vessel. The method also includes passing the medical device comprising a compressed blockstent and the delivery catheter through the guide catheter and positioning it in the lumen of the blood vessel. For this method, the delivery catheter portion of the medical device preferably comprises a cylindrical member with a single lumen configured to allow fluid to pass from the proximal end of the delivery catheter to the distal end of the delivery catheter and into the void of the blockstent, and not configured for a guidance member or guide wire. After the compressed blockstent is in position, the blockstent is expanded by passing fluid through the delivery catheter into the central void of the blockstent until the blockstent fills at least a portion of the blood vessel. The delivery catheter is separated from the expanded blockstent and removed, while the blockstent remains in place in an expanded state. The guide catheter and sheath are also removed. Resultantly, the blockstent is expanded so that at least 50% to at least 90% and up to 100% of the luminal surface of the blood vessel is filled by the expanded blockstent, or alternatively that at least 50% to at least 90% and up to 100% of the luminal surface of the blood vessel is in contact with the expanded blockstent. The method may further include the steps of shaping and/or sealing the expanded blockstent. The exterior surface of the blockstent optionally comprises pores or projections. The pores may have a diameter ranging in diameter from about 0.01 μm to about 100 μm. The projections may have a length that ranges between about 0.01 μm to about 157 μm.

Another method for placement of an expanded blockstent within a blood vessel segment includes the steps of accessing the vasculature with a needle, inserting a guide wire through the needle, removing the needle, and optionally, inserting a vascular sheath into the blood vessel. The method also includes the steps of advancing a diagnostic catheter over a guide wire until the tip of the guide wire is within or near the lumen of the blood vessel and removing the diagnostic catheter. The method further includes passing the medical device comprising a compressed blockstent and a delivery catheter over the guide wire, and positioning the compressed blockstent in the lumen of the blood vessel. For this method, the delivery catheter portion of the medical device preferably comprises at least two cylindrical members and two lumens, with one lumen configured to allow fluid to pass from the proximal end of the delivery catheter to the distal end of the delivery catheter and into the void of the blockstent, and another lumen configured for a guidance member or guide wire. After the compressed blockstent is in position, the blockstent is expanded by passing fluid through one of the cylindrical members of the delivery catheter into the blockstent until the blockstent is expanded to fill at least a portion of the blood vessel. Then the delivery catheter is separated from the expanded blockstent and removed, while the blockstent remains in place in an expanded state. Then the guide wire and sheath are also removed. Resultantly, the blockstent is expanded so that at least 50% to at least 90% and up to 100% of the blood vessel is filled by the expanded blockstent, or alternatively that at least 50% to at least 90% and up to 100% of the luminal surface of the blood vessel is in contact with the expanded blockstent. The method may further include the steps of shaping and/or sealing the expanded blockstent. The exterior surface of the blockstent optionally comprises pores or projections. The pores may have a diameter ranging in diameter from about 0.01 μm to about 100 μm. The projections may have a length that ranges between about 0.01 μm to about 157 μm.

The invention includes a kit with a medical device comprising a blockstent and a delivery catheter, and instructions on use. The medical device optionally further comprises components for separation of the expanded blockstent and the delivery catheter. In one embodiment, the instructions include the steps of placing a guide catheter near or within the lumen of the blood vessel, passing the medical device through the guide catheter, and positioning the compressed blockstent in the lumen of the blood vessel. After the compressed blockstent is in position, the instructions further include the steps of expanding the blockstent, until it fills the blood vessel, followed by separating the blockstent from the delivery catheter, and removing the delivery catheter, while the blockstent remains in the blood vessel in an expanded state. The instructions may further include the steps of shaping and/or sealing the expanded blockstent. In another embodiment, the instructions include the steps of placing a guide wire near or within the lumen of the blood vessel, passing the medical device over the guide wire, positioning the compressed blockstent in the lumen of the blood vessel, and removing the guide wire. After the compressed blockstent is in position, the instructions further include the steps of expanding the blockstent until it fills the blood vessel, followed by separating the blockstent from the delivery catheter, and removing the delivery catheter, while the blockstent remains in the blood vessel in an expanded state. The instructions may further include the steps of shaping and/or sealing the blockstent.

In other embodiments, the invention includes a method of manufacturing the blockstent. The method may include forming the wall of the blockstent through electroforming or electroplating on a cylindrical mandrel, a tapered mandrel, or a mold. The method may further include forming exterior or interior layers through electroforming, electroplating, sputtering, vapor deposition, or combinations thereof. The method for forming the external layer may further include methods to form pores or projections. The method further includes the steps of contacting the blockstent with a solution or suspension of a pharmaceutical, drug, or pharmacologically active molecules such that pharmaceutical, drug, or pharmacologically active molecules remain with the blockstent during placement of the blockstent in a blood vessel, thereby delivering the pharmaceutical, drug, or pharmacologically active molecules to a blood vessel segment. With this method, after positioning the expanded blockstent in the lumen of the blood vessel and leaving it in place, at least some of the molecules leave the blockstent and diffuse into the surrounding cells, tissues spaces, or fluids.

As such, a medical device comprising a blockstent and a delivery catheter is provided that can be used to occlude a segment of a blood vessel.

DETAILED DESCRIPTION

The present invention relates to a medical device comprising an expandable metal structure known as a “blockstent” and a delivery catheter. The blockstent is a thin-walled stent-like, cylindrical, device that can be expanded into a semi-rigid form that can remain in the body for an extended period. Specifically, the blockstent is configured for use in occluding segments of arteries, veins, and other biological conduits. The delivery catheter is configured to deliver the blockstent to a blood vessel and to provide a pathway, through a cylindrical member or lumen, for fluid to move into the central void of the blockstent, in order to expand it and fill at least a portion of the lumen of the blood vessel.

A cylindrical embodiment of the blockstent100with flat ends is shown inFIG. 1Ain an expanded state. This embodiment has an external proximal neck116that defines an opening112for the passage of fluids, liquids, gases, or solids into the central void of the blockstent. Another cylindrical embodiment of the blockstent100is shown inFIG. 1Bin an expanded state. This embodiment has an internal neck116that defines an opening112, also for the passage of fluids, liquids, gases, or solids into the central void of the blockstent. Embodiments of the delivery catheter400are shown inFIG. 2and inFIGS. 3A-B.

An embodiment of the medical device500is shown inFIGS. 3A-B. InFIG. 3Athe blockstent100is in a compressed state, which optionally includes pleats or folds. InFIG. 3Bthe blockstent100is in an expanded state. Expanding the blockstent100, as used herein, can refer to partial or complete expansion of the blockstent100using a fluid, a liquid, a gas, a solid, or a combination thereof. The delivery catheter400is used to advance the blockstent100into the lumen of the blood vessel. The delivery catheter400is also used to deliver a fluid, liquid, a gas, a solid, or a combination thereof, to expand the blockstent100in the lumen of the blood vessel. In one embodiment, an electrolysis wire320or an insulated conductor wire is connected to either a weld, or solder joining the blockstent and the delivery catheter, or to the blockstent itself.

As shown inFIGS. 4A-E, in one embodiment of the medical device500, the delivery catheter400advances the attached compressed blockstent100through the lumen of a larger guide catheter800, beyond the distal end of the guide catheter, and into the lumen701of the blood vessel700. Once the compressed blockstent100has been placed in the lumen701of the blood vessel700, the removable wire or obturator404is removed from the delivery catheter. The removable wire or obturator404may include a handle408or other device to facilitate insertion and removal. Then, a fluid source, such as the syringe314can be connected to the connection port406and fluid can be moved from the syringe314into the central void or space108of the blockstent100, resulting in expansion of the blockstent within the lumen701of the blood vessel700and filling of the blood vessel. As shown inFIGS. 4D-E, after the blockstent100is expanded, the delivery catheter400and the blockstent100are separated and the delivery catheter and guide catheter800are removed while leaving the expanded blockstent in the lumen701of the blood vessel700. A variety of methods and devices can be used to separate the catheter from the blockstent100. In one embodiment, the delivery catheter400comprises an electrolysis wire320or an insulated conductor wire. For this embodiment, after the blockstent100is expanded, a DC current is applied to the electrolysis wire320or the insulated conductor wire to dissolve a portion of the weld or solder316between the blockstent100and the delivery catheter400or alternatively to dissolve a portion of the blockstent100. Once the weld or solder316is dissolved, or alternatively a portion of the blockstent100is dissolved, the delivery catheter400is separated from the blockstent and the delivery catheter and the guide catheter800are removed.

Another cylindrical embodiment of the blockstent100is shown inFIG. 5Ain an expanded state. This embodiment has an external proximal neck116that defines an opening112for the passage of fluids, liquids, gases, or solids into the central void of the blockstent. This embodiment also has an external distal neck118that defines an opening114for the passage of a guide wire302. Another embodiment of the blockstent100is shown inFIG. 5Bin an expanded state. This embodiment has an internal proximal neck116that defines an opening112, also for the passage of fluids, liquids, gases, or solids into the central void of the blockstent. Further, this embodiment has an internal distal neck118that defines an opening114for the passage of a guide wire302.

Another cylindrical embodiment of the medical device500is shown inFIGS. 7A-B. InFIG. 7Athe blockstent100is in compressed state, which optionally includes pleats or folds. InFIG. 7Bthe blockstent100is in an expanded state. The delivery catheter300is used to advance the blockstent100over a guide wire302and into the lumen of the blood vessel. The delivery catheter300is also used to deliver a fluid, liquid, gas, solid, or a combination thereof, to expand the blockstent100in the lumen701of the blood vessel700. In one embodiment, an insulated conductor wire or an electrolysis wire320is connected to either a weld, or solder joining the blockstent and the delivery catheter, or to the blockstent itself.

As shown inFIGS. 8A-E, in one embodiment of the medical device500, the delivery catheter300advances the attached compressed blockstent100over a guide wire302and into the lumen701of the blood vessel700. Once the compressed blockstent100has been placed in the lumen701of the blood vessel700, the guide wire302is removed. Then the wire or obturator404is removed from the delivery catheter300. The wire or obturator404may include a handle408or other device to facilitate insertion and removal. Then, a fluid source, such as the syringe314is connected to the connection port308and fluid is moved from the syringe314into the central void or space108of the blockstent100resulting in expansion of the blockstent until it fills at least a portion of the lumen of the blood vessel701. As shown inFIG. 8D-E, after the blockstent100is expanded, the delivery catheter300and the blockstent100are separated and the delivery catheter is removed while leaving the expanded blockstent100within the lumen701of the blood vessel700. In one embodiment, the delivery catheter comprises an electrolysis wire or an insulated conductor wire is connected or electrically coupled to either a weld or solder joining the blockstent and the delivery catheter, or to the blockstent itself. For this embodiment, after the blockstent100is expanded, a DC current is applied to the electrolysis wire320or insulated conductor wire to dissolve a portion of the weld or solder316between the blockstent100and the delivery catheter300or alternatively to dissolve a portion of the blockstent100. Once the weld or solder316is dissolved, or alternatively a portion of the blockstent100is dissolved, the delivery catheter300is separated from the blockstent100and the delivery catheter100and the guide catheter800are removed.

The medical device500can be used as part of various methods and medical kits to occlude a blood vessel or other biological conduit, such as a ductus arteriosus, bronchus, pancreatic duct, bile duct, ureter, and fallopian tube. Alternatively, these systems, methods and medical kits can be used to treat a variety of medical conditions by using the systems, methods, and medical kits can be used to occlude biological conduits in patients in need thereof, the biological conduits including arteries, veins, vascular structures, ducts, airways, bile ducts, pancreatic ducts, enterocutaneous fistulas, ureters, fallopian tubes and urethras, among others. The medical kit includes the medical device and instructions for use. The medical kit may also contain additional components for carrying out a variety of treatments using the medical device500.

A typical method for using the medical device500to occlude a blood vessel includes accessing the vascular system of a human with a needle, passing a guidance member, or guide wire,302into the vessel, optionally placing a vascular sheath, advancing the medical device comprising a compressed blockstent100and a delivery catheter300or400and advancing it until the compressed blockstent is located in the lumen701of a blood vessel700. Then the blockstent100is expanded by passing a fluid, liquid, gas, or solid material, or combinations thereof, through the delivery catheter and into the central or internal void or space108of the blockstent. The delivery catheter and the expanded blockstent are then separated and the delivery catheter is removed from the body, while the expanded blockstent remains in place within the lumen701of the blood vessel700. The position of the blockstent100during and after the procedure may be monitored by any suitable methods, including fluoroscopy, computed tomography, MRI and ultrasound, including intravascular ultrasound.

The Blockstent

The blockstent100may be composed of a single continuous layer or wall102, as shown inFIG. 9A. The blockstent wall100comprises a material, preferably a metal that is biocompatible and ductile, that can form a thin-wall construction, and can assume a variety of shapes after expansion. By way of example and not limitation, the metal can be selected from the group consisting of gold, platinum, silver, nickel, titanium, vanadium, aluminum, tantalum, zirconium, chromium, silver, magnesium, niobium, scandium, cobalt, palladium, manganese, molybdenum, alloys thereof, and combinations thereof. Preferred metals include gold, platinum, and silver, alloys thereof, and combinations thereof. Alternative materials to metal can be used, such as a polymer, plastic, latex, rubber, an elastomer, fiber material, and combinations thereof. Blockstents can be made from alternative materials that can be formed into thin-walled structures that are sufficiently rigid or semi-rigid to tolerate compression and expansion, and can maintain an expanded state in vivo. Alternative materials include polymers or plastics that are reinforced with metal coils or braids, and other materials with similar properties. The materials comprising the wall of the blockstent and the thickness of the wall of the blockstent are selected such that the blockstent100has sufficient rigidity to remain in an expanded state in vivo under typical physiologic conditions after expansion and separation from the delivery catheter, even where the pressure inside and outside the central void or space108of the blockstent is the same or similar. The central layer122of the blockstent wall102has an interior surface106and exterior surface124that define a wall thickness120. In particular, forFIGS. 9A and 9B, the distance between the interior surface106and the exterior surface124is the overall wall thickness120of the wall102. Preferably, the central layer122of the blockstent wall102has a thickness120from about 3 μm to about 180 μm. The wall thickness120can be uniform. For example, the blockstent wall102may have a uniform thickness of 3 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 120 μm, or 180 μm. Alternatively, the thickness of the blockstent wall at different locations may vary in thickness. Alternatively, the blockstent100may be composed of a single porous layer or wall122, as shown inFIG. 9B, with pores1300wherein at least some pores extend all the way from the internal surface106to the external surface124. For this embodiment, the wall102may be of a uniform thickness or a varied thickness.

Alternatively, the blockstent100may have an additional coating or layer on the exterior surface124of the central layer122, as shown inFIG. 9C. The blockstent wall102and any additional exterior layers define an exterior surface110that, when expanded, contacts the internal wall of the blood vessel. The exterior layer104can be of a uniform or varied thickness, preferably between about 1 μm and about 59 μm. The exterior coating or layer104may be porous and contain a plurality of pores200, as shown inFIGS. 9C and 9D. Alternatively, the exterior layer104can be smooth, with limited porosity or projections. For example, the exterior layer104may be a polished metal surface. In one embodiment, portions of the exterior layer104can be smooth, while other portions can be porous or contain projections. In one embodiment, the surface variations can include a pattern. In particular forFIG. 9C, the distance between the interior surface106and the exterior surface110is the overall wall thickness120of the wall102.

The porous or spongy nature of the exterior layer104can contain (or be configured to contain) solutions that include drugs, pharmacologically active molecules, or pharmaceutical compositions within the pores200. As such, solutions such as drugs, pharmacologically active molecules, or pharmaceutical compositions can be delivered to the treatment site. Drugs, pharmacologically active molecules, or pharmaceutical compositions that promote thrombosis, stimulate cell proliferation or extracellular matrix productions, or tissue growth are examples that can be placed in the pores200. The drugs, pharmacologically active molecules, or pharmaceutical compositions are incorporated into the pores200of the wall or the exterior layer104prior to positioning the blockstent100at the desired location. The drug compositions may be delivered into the pores200via capillary or wicking action. The pores200range from about 0.01 μm to about 100 μm in diameter. Pore diameters for each blockstent may vary according to the specific drugs, pharmacologically active molecules, or pharmaceutical compositions to be incorporated and the desired rate of release from the blockstent in vivo. By way of example and not limitation, the blockstent100may have a porous exterior layer104where the pore diameter averages from about 0.01 μm to about 0.05 μm, about 0.05 μm to about 0.5 μm, 0.5 μm to about 5 μm, about 5 μm to about 25 μm, about 25 μm to about 100 μm, about 0.05 μm to about 100 μm or about 0.01 μm to about 100 μm for the blockstent.

The pharmaceutical drugs, pharmacologically active molecules, or pharmaceutical compositions may include thrombin, platelet-derived growth factor, Ethiodol®, Sotradecol®, or combinations thereof. Other pharmaceutical compounds and compositions that promote thrombosis and coagulation or stimulate cell proliferation, the synthesis of extracellular matrix, or the growth of tissue into the porous external wall of the blockstent100may also be used. Such drugs or pharmacologically active molecules pharmaceutical compositions may include molecules to promote cell proliferation, extracellular matrix production, or tissue growth, such that the expanded blockstent100will become more firmly attached to the tissue at the treatment location. The dosages and manner in which the pharmacologically active molecules, or pharmaceutical compositions are incorporated into the blockstent wall or exterior layer104are a matter of choice depending on the treatment performed. Other compounds may be used to promote blood clotting or thrombosis around the blockstent. For embodiments of the blockstent100with a porous layer104, over time, the blockstent100remains expanded with the blockstent eventually becoming affixed to the surrounding tissue. The exterior surface of the ballstent may also comprise one or more projections, as described, that can increase the strength of the attachment of the expanded blockstent to the adjacent tissue, and thereby reduce the risk of blockstent movement or migration. The projections may have a length that ranges between about 0.01 μm to about 157 μm. The projections can be microscopic and can have a branched construction. In some embodiments, the projections are rigid, or semi-rigid. In other words, embodiments, the projections are flexible and hair-like, and may further comprise globular ends, similar to the projections on the surface of the footpad of the gacko.

Alternatively, the blockstent100may comprise an additional layer or liner1400on the interior surface106of the wall102or central layer122, as shown inFIG. 9D. The interior layer may be made from the same materials as the central layer, or can be made of different materials. The interior layer may be comprised gold, platinum, silver, alloys thereof, or combinations thereof. The additional layer1400on the interior surface of the wall106of the central layer122of the blockstent100may also be composed of a polymer, plastic, latex, rubber, woven or knitted fiber material, metal, or another material, or combinations thereof. Preferably, the interior layer1400is an elastomeric coating that is bonded to the interior surface106of the central layer122. The interior layer1400can be a variety of thicknesses, preferably ranging between about 0.1 μm and about 59 μm. The total thickness of the wall102, including the central layer122, the exterior layer104, and the interior layer1400is preferably between 2 μm and 60 μm, regardless if the wall contains one, two, three, or more layers. The interior layer1400can be comprised of polymers, latex, or elastomers. In a preferred embodiment, the interior layer1400is comprised of Parylene™. The interior layer1400adds mechanical properties (such as strength) to the wall102. Further, the interior layer1400, optionally, can form a seal that prevents the escape of fluids from the blockstent100, should the central layer122of the wall102contain a defect, such as a defect or hole. The blockstent central layer122and any additional layers define an interior surface106or1410, such that when the blockstent is expanded, with a fluid, liquid, gas, or solid, a central void or space108is defined. In particular forFIG. 9D, the distance between the interior surface1410and the exterior surface110is the overall wall thickness120of the wall102.

Advantageously, the blockstent100can be delivered into the lumen701of a blood vessel segment700, expanded, and then separated from the delivery catheter300, such that the delivery catheter can be removed while the blockstent remains in place filling a portion, substantially all, or all of the lumen of the blood vessel in an expanded state. The expanded blockstent100will typically conform to the shape of the blood vessel segment cavity in which it is placed. The expanded blockstent100can also be shaped with external force, such as a physical force applied by the inflated balloon portion1102of an adjacent balloon catheter1100, as shown inFIG. 11. With precise placement and shaping, the blockstent can be positioned such that the treated blood vessel segment is completely or substantially filled and occluded without any portion of the blockstent sealed, and further with none of the blockstent, or a minimal amount of the blockstent, extending into the lumen of an adjacent blood vessel segment that is not intended for treatment the parent vessel1202, from which the aneurysm has formed.

As illustrated inFIGS. 1A-BandFIGS. 3A-B, the blockstent100has one or more openings112and114defined by the wall102or by one or more necks116and118. Fluid can enter the opening112to expand and move into the central void or space108defined by the interior surface106or1410, thereby expanding the blockstent. In various embodiments, one or both of the necks116and118can project away from the wall102of the blockstent100or they can project into the central void or space108of the blockstent100. The necks116and118can be used for attaching the blockstent to the delivery catheter and may function in separating the blockstent100from the delivery catheter. Additionally, the necks116and118can be designed and dimensioned such that the opening112can be closed or partially closed before, during, or after separation of the expanded blockstent from the delivery catheter. One or more openings112or114may remain open. Optionally, before, during, or after separation, the necks116and118may be folded, pinched or closed to form a seal. The necks116and118have a length ranging between about 0.5 mm and 60 mm, preferably a length between about 0.5 mm and about 5 mm. The necks116and118may define the openings112and114, respectively, having diameters between about 0.25 mm and about 2 mm. The necks116and118may protrude into the central void or space108for a length ranging between about 1 mm and 60 mm, and preferably for a length between about 0.5 mm and 5 mm, while defining the openings112and114, respectively, having diameters between about 0.25 mm and about 5 mm, and preferably having diameters between about 0.25 mm and about 5 mm. The thickness of the wall of either or both of the necks116and118may be the same as the main body of the blockstent or may be thinner than the wall of main body of the blockstent. Similarly, the thickness of the wall of either or both of the necks116and118may be thicker than the wall of the main body of the blockstent. Preferably, either or both of the necks116and118have a wall thickness between about 3 μm and about 60 μm. With an embodiment of the blockstent wherein the neck(s) extends into the central void or space108of the blockstent100the external surface of the blockstent retains a more rounded surface contour, and therefore there may be a reduced risk of damage to the blood vessel wall or the adjacent tissue with placement of the blockstent. One or both of the necks116or118can be coated with insulation on the inner wall, outer wall, or both, wherein a strip of conductive material, including an uncoated or uninsulated section of a weld or solder, or portion of the blockstent itself, is left exposed, uncoated, or uninsulated and whereby a conductive wire is in electrical contact with the blockstent100uncoated or uninsulated portion of the weld or solder, or blockstent100.

Various expanded blockstent shapes are acceptable, as required to treat blood vessel segment of various shapes, including circular, oblong, and irregular. Regardless of the formed shape, when a blockstent is expanded in the lumen or cavity701of a blood vessel700, the blockstent is designed to conform, at least partially, to the shape of the cavity.

In various embodiments, the dimensions of the blockstents100are selected based upon the size and shape of the blood vessel segment being treated. Preferred shapes of the blockstent100include cylindrical, oblong, and irregular. For example, the blockstent100may a cylinder with rounded, hemispherical, or flat ends. The diameter of the cylindrical expanded blockstent100ranges from about 2 mm to about 30 mm, and preferably has an expanded diameter ranging from about 1 mm to about 20 mm. The expanded length of oblong blockstents preferably ranges between about 5 mm to about 60 mm. The blockstent100may have an expanded volume that ranges between about 0.005 cc to about 65 cc. In preferred embodiments, the expanded diameter of the cylindrical blockstent100ranges from about 2 mm to about 10 mm, while the preferred expanded volume ranges from about 0.004 cc to about 40 cc. In preferred embodiments, the expanded length of the oblong blockstent100ranges between about 2 mm to about 20 mm.

In other embodiments, one or more portions of the blockstent wall102may be thicker than the remaining portions of the wall. By way of example and not limitation, the wall in the central portion middle of the body of the blockstent may be thicker than the wall in the proximal and distal portions of the blockstent, or in the neck(s) the wall of a neck may be thicker or thinner than the main body of the blockstent. Optionally, the entire blockstent wall can be porous, as shown inFIG. 9B, with pores extending from the internal surface106to the external surface124. During expansion of the blockstent of this embodiment, fluid may travel under pressure from the central void or space108of the blockstent, through the wall102and leave the blockstent at the exterior surface124. Preferably, for this embodiment, the pores range from 10 μm-1000 μm in diameter.

The blockstent comprises a central wall or layer122, optionally with an exterior wall or layer104, and also optionally with an interior wall or layer1400, as shown inFIG. 9C. As mentioned, the construct of the central layer or wall122and the layers104and1400can be uniform, porous, or combinations thereof.

In one construction, the central layer or wall122of the blockstent100is continuous and comprised of gold. To this preferred construction, an exterior layer104comprised of porous gold can be added. Additionally, an interior layer1400comprised of Parylene™ may be present. In certain embodiments wherein electrolysis is used to separate the expanded blockstent100from the delivery catheter, certain portions of the blockstent (such as the neck, or body) are coated with an insulator polymer, such as Parylene™ (including the external surface, the internal surface, or both the internal and external surfaces) while a portion of the neck or body remains uncoated or uninsulated. In this instance, the uncoated or uninsulated portion is solubilized by the passage of an electrical current into the uncoated or uninsulated portion during electrolysis. In certain embodiments, the uncoated or uninsulated portions are created by masking during the coating process. In other embodiments, the coating or insulation is removed from the uncoated portions, as through etching or ablation, such as with laser etching or laser ablation.

The central void or space108of the blockstent100can be filled with fluids, solids, or combinations thereof. A fluid is a substance having particles that easily move and change their relative position without a separation of the mass. Fluids that can be used to inflate or expand the blockstent100include liquids, gases, and combinations thereof. By way of example and not limitation, the fluid may be water, a saline solution, a radiographic contrast solution, or a mixture thereof. In one embodiment, the fluid may further include a solution or suspension of a drug or pharmacologically active molecules or a pharmaceutical preparation. By way of example and not limitation, the drug, pharmacologically active molecules, or pharmaceutical preparation may increase local thrombosis, cell proliferation, extracellular matrix production, or tissue growth into of around the wall102of the expanded blockstent when it is positioned in the lumen of a blood vessel segment.

In one embodiment, the shape of an expanded blockstent is maintained by placing solid material or support structures into the central void or space108of the expanded blockstent100. Examples of this solid material include metal or polymeric coils or wires, metal or polymeric solid support structures, radially expansile materials, beads, particles, spheres, or microspheres. In certain embodiments, these solid materials can also be used to help expand the blockstent. In other embodiments, these solid materials are added after the blockstent expansion. In one embodiment, as shown inFIG. 10, the blood vessel700adjacent to the blood vessel1202is filled with a blockstent containing at least one coil or expansile wire1204. In one aspect, the blockstent100may be expanded by the coil or expansile wire1204only, while in other aspects, the blockstent100may be expanded by a fluid and the solid materials may be added later to provide support to maintain the expanded shape of the blockstent. Other suitable biocompatible solid materials may also be used. The solid fill members can function as a lattice to insure the structural integrity of the blockstent100. For example, the coil1204can promote the structural integrity of the blockstent100and reduce compression of the blockstent. In one embodiment, solid material may be designed and manufactured to match a ballstent of a particular size or shape, and may be packaged as part of the medical device for use with the packaged ballstent.

Embodiments of the blockstent can include features designed to secure the blockstent in place once it has been expanded in the lumen of a blood vessel. These features can be biological or physical, or a combination thereof. In one embodiment, the exterior surface110of the blockstent100may be coated with molecules that can bind to adjacent thrombus or tissue. These molecules can be affixed to the blockstent through a variety of methods, including chemical bonds such as with hydrogen bonding or covalent bonding. Alternatively, these molecules can be affixed to the blockstent through encapsulation of a porous layer or encapsulation of projections. Representative molecules that can be affixed to the wall of blockstents include fibrin, and molecules that can link to fibrin through covalent and non-covalent bonding. With such a coating, the blockstent can be anchored to the fibrin-rich clot that forms between the blood vessel and the blockstent. In another embodiment, the blockstent100may comprise a porous external layer or wall104or a wall with external projections to promote thrombus formation on the external surface110or in the pores200of the blockstent and promote cell proliferation, extracellular matrix production, or tissue growth into or around the wall102of the ballstent100the porous layer, such that the blockstent100will, over time, become more strongly attached to the tissue in the adjacent blood vessel wall. As shown in another embodiment, the wall102or exterior surface124or110of the ballstent100further comprises one or more projections therefrom, which can be used to anchor the blockstent100to the surrounding tissue walls specifically of the blood vessel and hold the blockstent in the desired location. In a macroscopic form, the projections may be composed of nitinol or fibers or any other suitable biocompatible material. The projections may be straight, curved, hook-shaped, or configured as pigtail hooks1800as shown inFIG. 12A.FIG. 12Bdepicts an expanded blockstent100that is anchored to the wall1802of a blood vessel1804. The size and shape of the projections may be selected based upon the condition being treated, and may be designed and dimensioned to provide sufficient anchoring support without causing excessive damage to the wall of the blood vessel or the surrounding tissue. Alternatively, microscopic projections or filaments may be used to anchor the blockstent. For some embodiments, these microscopic projections range in length from 0.01 μM to about 157 μm, and can be straight or branching.

In order to facilitate advancement of the blockstent through the vascular system, some embodiments of the blockstent100comprise two or more metallic portions1900A-B that are joined by a flexible joint1902, as shown inFIG. 13. In certain embodiments, this flexible joint can comprise a variety of materials that are flexible and biocompatible, including various polymers or elastomers. The joint1902allows for better maneuverability and increased trackability as the compressed blockstent is advanced to the desired location. In other embodiments, the blockstent100may include three or more metallic or rigid portions that are joined through two or more flexible joints.

In order to facilitate advancement of the blockstent through the vascular system, the blockstent100can be compressed into various shapes and dimensions. Optionally, this compression can include various forms and patterns of folding or pleating. For example, one or more pleats can be made in the blockstent100and then the pleats can be wrapped into a cylindrical shape. Alternatively, the blockstent100may be flattened into a planar shape and then rolled into a cylindrical shape. Alternatively, the blockstent100may be compressed into a compact spherical shape. Additionally, the portions of the blockstent100may be twisted or braided during compression. In certain instances, the blockstent may be compressed around the delivery catheter300, as inFIG. 7A. In other instances, the blockstent may be compressed around the obturator404, as inFIG. 3A. In other embodiments, the blockstent100may be compressed on itself, without a central catheter or obturator.

InFIG. 14A, the blockstent100has been pleated, folded, and wrapped around the shaft hollow cylindrical member304of the delivery catheter2900, as shown inFIG. 14A. InFIG. 14B, the blockstent100has been similarly pleated and wrapped without the delivery catheter. In another embodiment, the blockstent100is folded into pleats, then the pleats of the folded blockstent are wrapped around the hollow cylindrical member304of the delivery catheter2900, and the blockstent is compressed against the delivery catheter. In another embodiment, the blockstent100is folded into pleats, then the pleated folds of the folded blockstent are wrapped around the removable guide wire302or obturator404, and then the blockstent is compressed against the removable wire or obturator404. In another embodiment, the blockstent100is folded into pleats, and then the pleated folds are rolled into a generally cylindrical shape without a removable wire, obturator, or catheter acting as central fixation point.

In various embodiments, the blockstent100is attached to the delivery catheter300,400, then the pleats are formed, and then the pleated folds are wrapped and compressed onto the delivery catheter300or2900, or the obturator404. In another embodiment, the blockstent100is first folded to form pleats, then attached to the catheter300,400, and then the pleated folds are wrapped and compressed onto the outer surface of the delivery catheter300,2900, or obturator404. In another embodiment, the blockstent100may be folded and compressed into a variety of shapes in a manner similar to Japanese origami, as shown inFIGS. 15A-D. [Nick—Do you want the origami pictures in Blockstent app?]

In various certain embodiments, the blockstent100need not be fully expanded to occlude a blood vessel segment. For example, the blockstent100may be partially expanded, or may be or completely expanded. In all embodiments, the blockstent remains in an expanded state (partially or completely) after detachment from the delivery catheter. An expanded state refers to the at least partial distention of the blockstent100, such as at least 10%, 20%, 50%, 75%, or 90% and up to 100% of the maximum blockstent volume.

The central layer122of the wall of the blockstent102and/or the interior and exterior layers1400and104, respectively, may be formed by any suitable method. For example, in a preferred embodiment, the central layer122of the wall102is formed by electroforming or electroplating. A conductive mandrel is placed in a solution of metal ions, which coat the mandrel to form a layer of the blockstent100. The shape of the blockstent100can be modified by modifying the shape of the mandrel. The thickness of the central layer122of the wall102can be modified by varying the process time. Regions of different wall thicknesses and the pattern of thickness differences may be produced by masking. In other exemplary methods of forming the blockstent100, the central layer122of the wall102of the blockstent100may be formed by vapor deposition, wherein vapors from one or more polymers, pure metals, or metal alloys are condensed upon a substrate or mold (not shown). The mold may be removed to provide a hollow shell composed of the pure metal or metal alloy.

An exterior layer104may be formed on the outside of the central layer122of the blockstent100by additional electroplating or electroforming, by vapor deposition or by sputter deposition, wherein material is eroded from a target (e.g., a metal or metal alloy) and is then deposited onto a substrate (e.g., a mandrel or mold) forming a thin layer on the substrate.

An interior layer1400may be formed on the inside of the central layer122of the blockstent100by additional electroplating or electroforming, or by vapor deposition or by sputter deposition.

An exterior layer104may be formed on the outside of the central layer122of the blockstent100by additional vapor deposition. In some instances, the central layer122may be formed by electroforming or electroplating and the interior and exterior layers are formed by vapor deposition.

In some instances, it may be desirable to incorporate an elastomer layer into the blockstent100, either as an interior or an exterior layer. In these instances, the elastomer can be added by incorporating a pre-formed material into the desired orientation, or by vapor deposition, or other methods.

The wall102of the main body of the blockstent100may be formed by different methods than the neck116. The central layer122of the blockstent100may be formed by different methods than the exterior layer or coating104or the interior layer or coating1400.

Two-dimensional sheets of metal may be manipulated and secured in the desired configuration to form the wall102and/or the exterior layer104. These two dimensional sheets may further comprise rubber, plastic, polymer, woven or knitted fiber materials, or other materials, or combinations thereof. By way of example and not limitation, one or more two-dimensional sheets of a metal may be folded into a blockstent shape and welded, soldered, glued, or bonded together. Similarly, two-dimensional sheets of material may be manipulated and secured to form the exterior layer104or the interior layer1400.

In various embodiments, a post forming wherein the wall102of the blockstent100comprises metal, an annealing process is used to improve ductility and facilitate folding, compressing, and/or expanding the blockstent100. By way of example and not limitation, a typical annealing process includes heating the blockstent100at approximately 300° C. for a period of about one hour followed by an immediate quench in distilled water at room temperature.

The Delivery Catheter

The blockstent100is advanced and positioned within human body by an elongated portion of the medical device known as the “delivery catheter device”. Typically, a delivery catheter device is an elongated surgical instrument that defines at least one lumen, or potential lumen, having a proximal and a distal end and that is dimensioned to deliver fluid from a fluid source at the proximal end into the central void or space108of the blockstent100, which is attached to the distal end. Further, any medical device or component of a medical device that can position the blockstent100at a desired location in the vascular system, such as the lumen of a blood vessel segment, facilitate the expansion of the blockstent, and then facilitate the separation of the blockstent from the delivery device is generally acceptable as a delivery device. Typically, the delivery device is a catheter (a “delivery catheter”). Preferably, the delivery catheter may be any catheter, hollow wire, removable core wire, needle, trochar, other type of device, or combinations thereof, suitable for accessing locations with the vascular system, including the delivery catheters300and400. The delivery catheter may also be any other type of catheter, hollow wire, or removable core wire, or alternatively a needle or trochar, or combinations thereof, suitable for accessing locations with the vascular system.

A catheter is a flexible, tubular, elongate medical device configured for insertion into bodily compartments, including blood vessels, to permit the injection or the withdrawal of fluids, amongst other functions. Catheters are often comprised of polymers or plastics and optionally further comprise metal, such as in a coil or braid configuration. Catheters can be configured to enable attachment to blockstents, facilitate the delivery of compressed blockstents to the lumen of a blood vessel, facilitate the expansion of compressed blockstents, and separate from expanded blockstents. The delivery catheter300or400can be configured to pass through the vascular system with the attached blockstent100in a compressed form, as shown inFIGS. 3A and 7A. After expansion, the blockstent100is separated from the catheter300, thereby allowing the expanded blockstent to remain in place while the delivery catheter is removed from the body. In this way, delivery catheters are similar to angioplasty balloons, which are configured to enable attachment to traditional tubular stents, to facilitate the delivery of attached compressed traditional tubular stents to the lumen of a specific segment of a blood vessel, enable expansion of compressed traditional tubular stents, and separate from expanded traditional tubular stents.

Preferably, the delivery device is a catheter400, as shown inFIG. 2andFIG. 3A, which can carry an attached compressed blockstent100to the lumen of a blood vessel segment. The delivery catheter400is composed of a biocompatible material. By way of example and not limitation, the delivery catheter300and400and various components thereof may be composed of silicone rubber, natural rubber, polyvinyl chlorides, polyurethane, copolyester polymers, thermoplastic rubbers, silicone-polycarbonate copolymers, polyethylene ethyl-vinyl-acetate copolymers, woven polyester fibers, or combinations thereof. In one embodiment, the wall of the hollow cylindrical member, or delivery catheter300and400, may be reinforced with a metal, such as coiled or braided stainless steel, nitinol or fibers, to enhance control and reduce kinking of the delivery catheter300and400during use. Metals suitable for delivery catheter reinforcement include stainless steel, nitinol or fibers.

As shown inFIGS. 2, 3A-B,6,7A-B and16A-B, the delivery catheter300and400will have a hollow, or potentially hollow, cylindrical member that defines a lumen to allow for passage of fluid from the proximal end of the delivery catheter to the distal end of the delivery catheter and into the central void108of the blockstent. The delivery catheter300or400is designed and dimensioned such that it can be inserted in the body to deliver the compressed blockstent100to a desired location, facilitate the expansion of the blockstent, and facilitate the separation of the expanded blockstent from the delivery catheter. When a single lumen delivery catheter400is used, the compressed blockstent may be positioned in the lumen of a blood vessel segment after being advanced through a separate larger guide catheter that is positioned with its distal end within or near the blood vessel. Once in the lumen of the blood vessel and out of the guide catheter, the compressed blockstent100can be expanded, and then the expanded blockstent and the delivery catheter can be separated, and the delivery catheter and the guide catheter can be removed from the body, while the expanded blockstent remains in place. The hollow, or potentially hollow, cylindrical member306of delivery catheter400has a wall thickness ranging from about 0.05 mm to about 0.25 mm. Preferably, wall thickness of the hollow cylindrical member306ranges from about 0.1 mm to about 0.2 mm. The lumen312defined by the hollow cylindrical member306for the purpose of enabling the passage of fluid into the central void or space of the blockstent108has a diameter ranging from about 0.4 mm to about 1.0 mm. The proximal end of the hollow cylindrical member306includes a port or hub308or406to communicate with a pressurized fluid source, such as a syringe314or a pump (not shown) containing, for example, water, saline or a radiographic contrast solution. Fluids for expanding the blockstent are received into the delivery catheter300or400through the hub or port308or406.

For some embodiments, the medical device is advanced in the body over a guidance member302, as shown inFIG. 8B. Examples of a guidance member include a flexible guide wire. The guide wire302can comprise metal in the form of a flexible thread, coil, or slender rod. For example, the basic angiography guide wire consists of a fixed solid metal core covered by a metal spring coil. In other situations, a delivery catheter is advanced over a needle or trochar. The guide wire302occupies a lumen in the delivery catheter, with such lumen defined by the tubular portion of the delivery catheter. Once located in place, the guide wire302or trochar can be removed in order to allow the injection or withdrawal of fluids.

As shown inFIG. 6andFIG. 16B, the delivery catheter300may include an additional hollow cylindrical member that defines a second lumen324to receive a guidance member, such as a guide wire302, to assist in the guidance of the blockstent100component of the medical device to the desired location. This second lumen324is generally adjacent and parallel to the first lumen312. As shown inFIG. 6andFIG. 16Bthe delivery catheter may be a double lumen catheter, with one lumen312configured to enable the passage of fluid from a fluid source at the proximal end of the delivery catheter to the central void or space108of the blockstent at the distal end of the delivery catheter, and the other lumen324configured to accept a guidance member, such as a guide wire302, to facilitate advancement and positioning of the medical device in the vascular system. As shown inFIG. 16B, the delivery catheter300includes two hollow cylindrical members, each with a lumen, wherein the hollow cylindrical members304or306have a wall thickness ranging from about 0.05 mm to about 0.25 mm. Preferably, the hollow cylindrical member304or306wall thickness ranges from about 0.1 mm to about 0.2 mm. The lumen defined by the hollow cylindrical member304for the accepting a guide wire302has a diameter ranging from about 0.25 mm to about 0.5 mm. The diameter of the lumen for the passage of fluid into the blockstent312and the diameter of the lumen for accepting a guidance member324may be similarly dimensioned. Alternatively, the diameter of the lumen for the passage of fluid into the blockstent may be larger or smaller than the diameter of the lumen for accepting a guidance member. For a delivery catheter with two lumens, the first and second hollow cylindrical members may be similarly dimensioned. Alternatively, the second hollow cylindrical member may have a larger diameter to accept the guidance member, or a smaller diameter. The proximal end of the second hollow cylindrical member304includes a guide wire port310. The guide wire port310facilitates the insertion of the guide wire302into the second hollow cylindrical member304. The guide wire302is fed through the second hollow cylindrical member304and extended out of the distal end of the delivery catheter300. In this embodiment, the delivery catheter300is advanced over the guide wire302until the compressed blockstent100is positioned in the lumen of a blood vessel segment. Once the compressed blockstent100is in the desired position, the blockstent100is expanded by fluid provided to the first hollow cylindrical member306by the syringe314connected to the blockstent expansion port308or406. Fluids such as saline, solutions of radiographic contrast agents, or solutions of drugs, such as thrombin, can be used to expand the compressed blockstent. The guide wire302is preferably an angiographic wire of sufficient length for the distal tip of the guide wire to reach the blood vessel, and a proximal end extending out and away from the point of entry into the vascular system. In some embodiments, the guide wire302has a straight or angled distal tip, while in other embodiments, the guide wire302has a curved J-shaped distal tip, typically constructed from a shape-memory alloy or a braided metal that causes the tip to return to the J-shape after any applied stress is removed. The materials and dimensions of the guide wire302may be selected based upon the diameter, length, and tortuosity of the blood vessels being traversed. Typically, the guide wire302may be composed of any suitable biocompatible materials and have an outer diameter ranging between 0.3 mm to 0.95 mm.

FIGS. 3A-Bdepict longitudinal views of a single lumen embodiment of the delivery catheter portion of the medical device500.FIG. 3Adepicts a longitudinal views of a single lumen embodiment of the medical device500with the blockstent in a compressed form.FIG. 3Bdepicts a longitudinal view of a single lumen embodiment of the medical device500with the blockstent in an expanded form.FIGS. 7A-Bdepict longitudinal views of a double lumen embodiment of the delivery catheter portion300of the medical device500.FIG. 7Adepicts a longitudinal view of a double lumen embodiment of the medical device500with the blockstent in a compressed form.FIG. 7Bdepicts a longitudinal view of a double lumen embodiment of the medical device500with the blockstent in an expanded form. As shown inFIGS. 8A-E, the delivery catheter300moves over the guide wire302to deliver the blockstent100to the lumen of a blood vessel segment701, to deliver fluid to expand the blockstent in the blood vessel, and then separate therefrom. In certain embodiments, a modified infusion wire having a removable core can be used as a single lumen delivery catheter. An infusion wire is a modified guide wire wherein the solid metal core can be removed to leave a lumen that can be used to inject fluids. An infusion wire with a removable core can be modified such that a blockstent can be attached to the distal end and expanded through the wire lumen, after the removal of the core wire.

FIG. 2depicts a longitudinal view of a single lumen embodiment of the delivery catheter portion400of the medical device500. As shown inFIGS. 4A-E, for the single lumen embodiment, the delivery catheter300moves through the lumen of a guide catheter800to deliver the compressed blockstent100to the lumen701of a blood vessel segment700. For this single lumen embodiment, the delivery catheter400does not include a hollow cylindrical member that defines a lumen that is dimensioned to allow for the passage of a guidance member, or guide wire.

FIG. 6depicts a longitudinal view of a double lumen embodiment of the delivery catheter portion300of the medical device500. As shown inFIGS. 8A-E, for the double lumen embodiment, the delivery catheter300moves over a guidance member or guide wire302to deliver the compressed blockstent100to the lumen701of a blood vessel segment700.

As shown inFIGS. 17A-B, in another embodiment, the delivery catheter of the medical device can be configured with a lumen that can accept a guide catheter800as a guidance member. With this configuration, the medical device can be advanced in a tri-axial configuration, with the medical device500advanced over a guide catheter800, which is advanced over a guide wire. In certain embodiments, the proximal hub on the guide catheter can be removed to allow the lumen of the hollow cylindrical member304of delivery catheter300of the medical device500to accept the guide catheter800. In certain instances, this embodiment of the medical device can result in better control over the delivery of the compressed blockstent to the blood vessel and better trackability of the compressed blockstent100as it is advanced to the desired location. As shown, in one aspect, the hollow cylindrical member304of delivery catheter300may be annular shaped and fully encircle the guidance catheter800, while in other aspects, the delivery catheter may engage 60%, 70%, 80%, 90% or more of the circumference of the guidance catheter.

The dimensions of the delivery catheter300or400are a matter of design choice depending upon the size of blood vessel to be treated and the location of the blood vessel in the vascular system. The distance between the blood vessel to be treated and the site of insertion of the delivery medical device into the vascular system, will determine, in part, the length of the delivery catheter300or400. Delivery catheter lengths range between 5 cm and 300 cm, with preferable ranges between 75 cm and 225 cm. The smallest diameter blood vessel segment in the path between the site of insertion of the medical device into the vascular system and the blood vessel to be treated, will determine, in part, the diameter of the delivery catheter. Delivery catheter diameters range between 2 Fr and 7 Fr, with preferable ranges between 3 Fr and 5 Fr.

In some embodiments, the proximal end of the delivery catheter400is configured with a Luer hub or taper406or308that may facilitate a Luer-Lok™ or Luer-Slip™ type connection for connecting a fluid source, such as a syringe314, to the lumen312of a hollow cylindrical member configured to transmit fluid from the proximal end of the delivery catheter to the central void or space of the blockstent100. As shown, inFIG. 28, the lumen312of a delivery catheter400is connected to a fluid source, such as the syringe314, through a female Luer fitting2802. A stopcock2804may be positioned between the fluid source and the delivery catheter400to enable greater control over, the movement of fluid into and out of the delivery catheter.

Attaching the Blockstent to the Delivery Catheter and Separating the Expanded Blockstent from the Delivery Catheter

The blockstent100may be attached to, or engaged with, the delivery catheter in a variety of ways. For example, the blockstent100may be affixed to the delivery catheter by a friction fit, using an adhesive or glue, by a weld or solder, by a junction or uniting of components, or by the application of a compressive force from a clamp, ring, elastomer sleeve or wrap, or compressive balloon. Various methods and devices may be used to separate the expanded blockstent from the delivery catheter. By way of example and not limitation, these methods and devices may be broadly categorized as physical or mechanical, electrical, thermal, chemical, hydraulic, and sonic.

In one embodiment, a physical or mechanical attachment is made between a blockstent and a delivery catheter, wherein the coupled parts are configured to fit tightly together and remain together by friction. After expansion of the blockstent, the physician slips the distal end of delivery catheter out of the neck of the blockstent to effect separation, a process that may be facilitated by moving a guide catheter800forward to abut the expanded blockstent100prior to withdrawing the delivery catheter as shown inFIG. 23B. For example, in one embodiment shown inFIG. 18, the neck1600of the blockstent100is inverted and located within the central void or space108of the blockstent. The exterior surface1602of the neck1600engages the distal end of the hollow cylindrical member306of the delivery catheter400by friction. When the blockstent100is compressed, it engages the distal end1706of the core wire or obturator404by friction. As shown inFIGS. 18, 22A-B, and23A-B, the distal portion1706of the core wire or obturator404of the delivery catheter400has a smaller diameter than the more proximal portion1707. In other embodiments, the distal portion1706of the core wire or obturator404of the delivery catheter400has the same diameter as the more proximal portion1707. After the compressed blockstent100is positioned in the lumen of a blood vessel segment, the core wire or obturator404is removed. This creates a fluid pathway1710through the delivery catheter400to the central void or space108of the blockstent100. Once the obturator404is removed, the blockstent100can be expanded. After the blockstent100is expanded, the distal end of the guide catheter800is advanced forward against the wall of the expanded blockstent100and the distal end of the delivery catheter400is withdrawn from the neck of the blockstent1600to separate the delivery catheter from the expanded blockstent, allowing the delivery catheter to be removed while leaving the expanded blockstent in the lumen of the blood vessel segment. In this way, the guide catheter800functions as a buttress against the exterior surface of the blockstent112, while the expanded blockstent is separated from the delivery catheter. Alternatively, the blockstent and delivery catheter can be separated by other physical methods.

In another embodiment, a mechanical attachment is made between a blockstent and a delivery catheter wherein an external neck1714on the110blockstent is configured to fit tightly around the distal end of the hollow cylindrical member306of the delivery catheter400. An elastic sleeve or wrap1724is attached to the distal end of the hollow cylindrical member306of the delivery catheter400and extended around at least a portion of the external neck of the blockstent1714of the blockstent100to hold the neck of the blockstent against the distal end of the hollow cylindrical member306of the delivery catheter400, a configuration shown inFIG. 24. Once in place the blockstent is separated from distal end of the hollow cylindrical member306of the delivery catheter by using the guide catheter, similar to above, to buttress the blockstent while the distal end of the hollow cylindrical member306of the delivery catheter400is pulled away from the expanded blockstent.

In another embodiment, the blockstent100is attached to the distal end of the hollow cylindrical member306of the delivery catheter300or400with an adhesive, glue, weld, or solder. In this embodiment, the blockstent100is separated from delivery catheter300or400by mechanical methods. The expanded blockstent100may be separated from the delivery device by a number of mechanical methods that cut, tear, or otherwise physically degrade a portion of the blockstent to separate the remainder of blockstent from the delivery catheter300or400.

As shown inFIG. 19, in one embodiment, a flexible, thin loop of material2200may be positioned to encircle the outside of the external neck of the blockstent116or2202. The loop of material can be comprised of various thin, strong, and flexible materials such as a wire, polymer strand, filament, string, thread, or snare. After expansion of the blockstent, the loop can be pulled toward the proximal end of the delivery catheter2204to sever the neck116or2202of the blockstent100, and separate the expanded blockstent from the delivery catheter. Preferably, the loop is pulled through a lumen in the delivery catheter dimensioned to accept the loop as it is pulled back. In another embodiment (not shown), a flexible thin loop of material (in certain embodiments representing a loop snare or modified loop snare) can be advanced by a second catheter until the loop is placed around the outside of the proximal portion of the external neck of an expanded blockstent. The loop can then be snugged against the neck and withdrawn into the second catheter in order to sever the neck116of the blockstent100and separate the blockstent from the delivery catheter.

In another embodiment, shown inFIG. 19, a distal end2500of a thin loop of material (such as a wire, polymer strand, filament, string, or thread) is affixed in a loop to the blockstent neck2202, while the proximal end2506of the loop material extends to the proximal end of the delivery catheter2508. After expansion of the blockstent100, the loop of material is pulled toward the proximal end of the delivery catheter2204, which tears a portion of the neck2202away from the expanded blockstent100to separate the blockstent from the delivery catheter.

In another embodiment shown inFIGS. 20A-C, the neck2202of the blockstent100may be cut by one or more blades2302A-D. In this embodiment, a cutting device2304is advanced over the delivery catheter2204. The cutting device2304has a cutting region2308that includes the blades2302A-D. When the expanded blockstent100is to be separated from the delivery catheter, the cutting device2304is positioned such that the neck2202is within the cutting region2308. The blades2302A-D may then be actuated to sever the neck2202. By way of example and not limitation, the blades2302A-D may be actuated by rotation of the cutting device, insertion of a wire, retraction of a wire, or other suitable methods.FIGS. 20B-Care cross-sectional views along line B-B of the cutting region prior to (FIG. 20B) and during actuation of the blades (FIG. 20C).

In another embodiment, shown inFIG. 21, the neck2202of the blockstent100may define a plurality of circumferential perforations2406that may be torn to separate the blockstent from the delivery catheter2204.

In another embodiment, a ring structure is fixed to the distal end of the delivery catheter, while a second ring structure is fixed to the proximal end of the blockstent, with a mating of the two rings attaching the blockstent to the delivery catheter. After expansion of the blockstent, the rings can be disengaged, resulting in separation of the expanded blockstent100and the delivery catheter. The unlocking of the rings could be accomplished by actuating a spring-loaded clamp or other similar methods in order to release the blockstent.

In other embodiments, hydraulic methods may be used to separate the expanded blockstent100from the delivery catheter device. In one embodiment, the expanded blockstent100separates from the delivery catheter after fluid is injected through a lumen to actuate a mechanical joint between the blockstent100and the delivery catheter, resulting in separation of the expanded blockstent100and the delivery catheter.

In one embodiment, a mechanical attachment is made between a blockstent and a delivery catheter wherein a portion of the blockstent is attached to the distal portion of the delivery catheter using one or more welds or solder316that are not insulated, and sensitive to electrolysis. For this embodiment, an insulated conductor wire or an electrolysis wire320extends along the length of the delivery catheter from the proximal end of the delivery catheter300or400. The electrolysis wire320or an insulated conductor wire can electrically couple a source of electrical current outside the patient's body, to the distal portion of the delivery catheter where it is coupled to the weld or solder that attaches the blockstent to the delivery catheter. In this way, the electrolysis wire320or the insulated conductor wire is in electrical communication with the weld or solder that attaches the blockstent to the delivery catheter. In various embodiments, the electrolysis wire320or the insulated conductor wire or the electrolysis wire320can lie within the wall of the delivery catheter300or400, along the exterior surface of the delivery catheter, or within a lumen of the delivery catheter. The electrolysis wire320or the insulated conductor wire is in electrical communication with the weld or solder between the blockstent and the delivery catheter. In some embodiments, the electrolysis wire320is insulated, wherein the weld or solder is not insulated. In other embodiments, the electrolysis wire320and the weld or solder316is not insulated, but a portion of the blockstent100is not insulated. In some embodiments, the electrolysis wire320and the blockstent100are insulated, while the weld or solder316is not insulated. An electrical current or charge is applied to the electrolysis wire320or the insulated conductor wire after the blockstent100is expanded. The current is applied in an amount and for a time sufficient to dissolve at least a portion of the weld or solder and separate the delivery catheter from the blockstent100, leaving the blockstent expanded at the desired position while the delivery catheter is removed. In one embodiment the current is applied in an amount and for a time sufficient to dissolve at least a portion of the blockstent and separate the delivery catheter from the blockstent100, leaving the blockstent expanded at the desired position while the delivery catheter is removed. In one embodiment the current is a direct current (DC) while in another embodiment, the current is an alternating current (AC). The electrolysis wire320or the insulated conductor wire is in electrical communication with the weld or solder316. In this embodiment, a DC current is applied to the electrolysis wire320or the insulated conductor wire after the blockstent100is expanded. The DC current dissolves at least a portion of the weld or solder316, resulting in separation of the blockstent100and the delivery catheter, and leaving the blockstent100expanded at the desired position while the delivery catheter is removed.

FIG. 28depicts another embodiment for separating an expanded blockstent and the delivery catheter by electrolysis. For this embodiment, a portion of the blockstent100is affixed to the delivery catheter400by an adhesive318. An electrolysis wire320or an insulated conducting wire extends along the length of the delivery catheter from the proximal end of the delivery catheter400, where it can be coupled to a power source or sources of electrical current3100outside the patient's body, to the distal portion of the delivery catheter where it is coupled to the proximal portion of the blockstent100. In this way, the electrolysis wire320or insulated conducting wire is in electrical communication with the portion3102of the blockstent that is not insulted3102and that is not bonded to the delivery catheter. In various embodiments, the electrolysis wire320or insulated conductor wire can lie within the wall of the delivery catheter400, along the exterior surface of the delivery catheter, or within a lumen of the delivery catheter. In another embodiment, the insulated conductor wire or the electrolysis wire320is in electrical communication with the proximal portion of the blockstent3102. In some embodiments, the electrolysis wire320is insulated, wherein a proximal portion3102of the blockstent100is not insulated. In some embodiments, the electrolysis wire320and the remainder of the blockstent100and116are insulated, while a proximal portion3102of the blockstent100is not insulated. An electrical current or charge is applied to the electrolysis wire320or insulated conductor wire after the blockstent100is expanded. The current is applied in an amount and for a time sufficient to dissolve at least a portion of the non-insulated portion of the blockstent3102, resulting separation the delivery catheter from the blockstent100, leaving the blockstent expanded at the desired position while the delivery catheter is removed. In one embodiment the current is a direct current (DC) while in another embodiment, the current is an alternating current (AC). In this embodiment, a DC current is applied to the insulated conductor wire or electrolysis wire320after the blockstent100is expanded. The blockstent100functions as a cathode, while a grounding pad3106functions as an anode. The DC current dissolves at least a portion of the non-insulated portion3102of the blockstent100, resulting in separation of the blockstent100and the delivery catheter, and leaving the blockstent100expanded at the desired position while the delivery catheter is removed. In one embodiment, the exterior, the interior, or both of the blockstent neck116may be coated with an insulating substance, such as a polymer including but not limited to Parylene™. In another embodiment, the exterior, the interior, or both of the blockstent neck116and the blockstent (except for portion3102) may be coated with an insulating substance, such as a polymer including but not limited to Parylene™. The electrolysis wire320or the insulated conductor wire is then brought into physical contact, or otherwise electrically coupled with a portion3102of the neck116that is uncoated and not otherwise insulated. The uncoated portion3102of the neck116may be intentionally left uncoated during the coating process or may be exposed after coating by laser etching or ablation, as with a laser, or other suitable processes. The remainder of the blockstent may be coated and insulated (inside surface, outside surface, or both surfaces) to reduce the time required to dissolve the portion3102of the blockstent that is not coated or insulated.

In another embodiment, as shown inFIGS. 25A-B, a mechanical attachment is made between a blockstent and a delivery catheter wherein a portion of the blockstent is attached to the distal portion of the delivery catheter using one or more bonds that are sensitive to an adhesive or binding agent2700that melts with heating, such as with a low melting temperature binding agent applied between the hollow cylindrical member306of the delivery catheter and the blockstent. After expansion of the blockstent, an electrical current is passed through the bond, generating heat by using a resistance heating element2702in electrical communication with a conduction wire2704, as shown resulting in warming of the adhesive or binding agent. As the binding agent2700is melted, the blockstent100is separated from the delivery catheter2706. The binding agent2700may be metal (e.g. gold foil) or a polymer binding agent that is positioned at the neck of the blockstent.

In another embodiment, a mechanical attachment is made between a blockstent and a delivery catheter wherein a portion of the blockstent is attached to the distal portion of the delivery catheter using one or more bonds that are sensitive to chemical dissolution. The bonding medium may be composed such that the bonding medium dissolves when contacted by a solution with a high salt concentration, an acid, a base, or a specific chemical. By way of example and not limitation, a cover or other shielding device may be removed from the region where the blockstent100is joined to the delivery catheter to expose the bonding medium. Also by way of example and not limitation, injection or infusion of a solution with a high salt concentration, an acid, a base, or a specific chemical to the region of the bonding, after expansion of the blockstent at the desire location can result in dissolution of the bonding medium and separation of the expanded blockstent and the delivery catheter.

In another embodiment, a mechanical attachment is made between a blockstent and a delivery catheter wherein a portion of the blockstent is attached to the distal portion of the delivery catheter using one or more adhesives, glues, bonds, welds, or solder that are sensitive to sonic waves. In this embodiment, the bond between the blockstent100and the delivery catheter is broken using sound waves, such as focusing pulsed ultrasound waves, resulting in separation of the delivery catheter and the expanded blockstent.

In one embodiment, the wall opening of the expanded blockstent100is left open at the end of the procedure. In other embodiments, the wall opening of the expanded blockstent100is closed prior to the end of the procedure. By way of example and not limitation, an opening may be sealed by applying an external force, such as with the inflation of the balloon portion of a balloon catheter adjacent to the expanded blockstent. Alternatively, an opening may be sealed by snugging a loop of flexible material around the external surface of the neck of the blockstent100prior to separation of the expanded blockstent and the delivery catheter. In this method, the loop of material may comprise a wire, polymer strand, filament, string, thread, or snare.

In all embodiments, the blockstent100retains its expanded shape after detachment and is resistant to compression. The blockstent100remains expanded even if the pressures inside and outside of the expanded blockstent are equal or similar because of the rigidity of the wall of the blockstent. In another example, maintenance of the blockstent expansion is assisted by placing rigid, semi-rigid, or expansile materials into the blockstent100as needed. Examples of these materials include metallic or polymeric coils, metallic or polymeric expansile structures, beads, balls, spheres, or microspheres.

According to any of the methods where the blockstent100is separated from delivery catheter, one or more radiopaque markers may be incorporated into the appropriate portions of the blockstent or delivery catheter to assist in the positioning of the blockstent, expansion of the blockstent, separation of the expanded blockstent from the delivery catheter, and removal of the delivery catheter after separation. For example, a radiopaque marker band or spot may be incorporated into the medical device to identify the location where separation is designed intended to occur. In addition, radiopaque material may be incorporated into the blockstent. Also, a radiopaque spot or marker band or spot may be incorporated into distal end of the delivery catheter so that the tip of the delivery catheter can be seen under fluoroscopy while pulling the delivery catheter away from the expanded blockstent. A radiopaque marker may also be placed onto the detachment components, as need be. The radiopaque spot or marker band may be comprised of various radiodense materials, including but not limited to a metal band, a metal spot or line, or a line of barium.

Methods of Use

Methods of the present invention generally include placing a compressed blockstent100into the lumen701of a blood vessel segment700using a delivery catheter300or400and expanding it to fill all or a substantial portion of the lumen of the blood vessel, thereby occluding it. As part of the method, the delivery device can be positioned using a guide catheter800or guide wire302, which have been placed in or near the blood vessel700. Once the blockstent100is expanded, the delivery catheter300or400is separated from the blockstent, which remains in the lumen701of the blood vessel700in an expanded state. Attaching of the blockstent100to the delivery catheter300or400and separation of the expanded blockstent and the delivery catheter can be accomplished via a variety of methods, as disclosed herein.

The shape of a blockstent100that has been expanded in the lumen of a blood vessel segment is determined, in part, by the formed shape of the blockstent. For example, in some embodiments, the blockstent100is manufactured into a cylindrical, oblong, irregular, or non-spherical orientation to match the contours of the cavity for a particular blood vessel segment700. The expanded shape is also determined by the size and shape of the lumen of the blood vessel segment. The expanded shape can also be determined by the application of an external force, such by inflating the balloon portion of a balloon catheter adjacent to the expanded blockstent. In certain embodiments of the methods, the balloon portion1102of a balloon catheter1100is inflated in the lumen of the parent blood vessel1202adjacent to the expanded blockstent100in the lumen of the blood vessel, thereby pushing the wall1104of the blockstent100toward the blood vessel. In other embodiments, the blockstent100is manufactured into a non-spherical orientation to match the contours of the cavity for a particular blood vessel segment700.

In all embodiments, the expanded shape of the blockstent100is determined by these factors: 1) the manufactured shape of the blockstent100; 2) the degree of blockstent expansion; 3) the size and shape of the blood vessel700; and 4) the effect of any applied external force on the blockstent after expansion. By way of example and not limitation, the manufactured size and shape of the blockstent100may be determined by making measurements of the blood vessel700. The measurements can be made by using medical images, including two dimensional and three dimensional reconstructions, and standard distance reference markers. Other methods of measuring the blood vessel may also be used.

In another embodiment, the blockstent100may position, size, and shape of the expanded blockstent can be manipulated and configured in vivo or even in situ while positioned within the blood vessel700. In this embodiment, it is not necessary to determine the precise contours of the blood vessel700prior to inserting the blockstent100. The blockstent100is shaped by the degree of expansion of the blockstent and the application of internal and/or external forces. For example, an external force may be applied by inflating the balloon portion of a balloon catheter adjacent to the expanded blockstent, or by tools inserted through or around the delivery catheter400or guide catheter800. In other embodiments, the blockstent100may be shaped in a step prior to or after the step of separating the expanded blockstent from the delivery catheter400.

In embodiments, the blockstent is designed so that the exterior surface110of the expanded blockstent100makes contact with a substantial portion of the inner surface704of the blood vessel700. In some embodiment, the exterior surface110of the blockstent100makes contact with at least 50%, 75%, 90% or more of the inner surface704of the blood vessel700including up to 100%. In embodiments, the expanded blockstent is designed to fill the lumen of the blood vessel701. In one embodiment, the expanded blockstent110fills at least 50%, 75%, 90% or more of the volume of the lumen701of the blood vessel700including up to 100%.

In all embodiments, the blockstents are configured to maintain their expanded shapes and expanded blockstents are not designed for, or intended to be, compressed or flattened into disc-like structures before or after separation from the delivery catheter.

By way of example and not limitation, a method of using the device500to treat a patient may include the steps of examining a patient and collecting diagnostic medical images to identify a blood vessel segment. The vascular system may be accessed using any suitable method including accessing an artery or vein using the Seldinger technique. A guide wire302is then inserted into the vascular system. Then a guide catheter800is inserted into the vascular system and advanced into or near the lumen of the blood vessel segment. The blood vessel is visualized by use of an injected radiopaque dye. The guide wire302is removed and the medical device500is then inserted through the guide catheter800until the compressed blockstent is advanced into the lumen701of the blood vessel700. The blockstent100is then expanded in the lumen701of the blood vessel700. A radiographic contrast solution may be injected into the adjacent vessel1202near the blood vessel700to confirm that the size of the expanded blockstent100is appropriate and that it is properly positioned in blood vessel. Once proper placement and sizing of the expanded blockstent100has been confirmed, the expanded blockstent is separated from the delivery catheter300or400by any of the methods disclosed herein, and the delivery catheter is removed. The expanded blockstent100is left in the patient, where subsequent examination may be conducted to determine if additional treatment is necessary. The expanded blockstent100left in the patient functions to prevent bleeding or expansion of the blood vessel and it alleviates future medical problems the patient might experience had the blood vessel700not been treated.

By way of example and not limitation, a method of using the device500to treat a patient may include the steps of examining a patient and collecting diagnostic medical images to identify a blood vessel segment. The vascular system may be accessed using any suitable method including accessing an artery or vein using the Seldinger technique. A guide wire302is then inserted into the vascular system. Then a guide catheter800is inserted into the vascular system and advanced with the guide wire302until the guide wire302is positioned in or near the lumen of the blood vessel segment. The blood vessel700is visualized by use of an injected radiopaque dye. The guide catheter800is removed and the medical device500is then inserted over the guide wire until the compressed blockstent100is advanced into the lumen701of the blood vessel700. The guide wire302is removed. The blockstent is expanded100in the lumen701of the blood vessel700. A contrast solution may be injected into the adjacent vessel1202near the blood vessel700to confirm that the size of the blockstent100is appropriate and that it is properly positioned in the vessel, and that the treated vessel is occluded. Once proper placement and sizing of the expanded blockstent100has been confirmed, the expanded blockstent is separated from the delivery catheter300or400by any of the methods disclosed herein and the delivery catheter is removed. The expanded blockstent100is left in the patient, where subsequent examination may be conducted to determine if additional treatment is necessary.

In various embodiments, a medical kit may be provided for treating a patient with the medical device. The medical kit may include the medical device500, a guide wire302, one or more guide catheters800, one or more blockstent support structures and methods for separating the expanded blockstent100from the delivery catheter300or400including separate medical devices for separation, components of the medical device500for separation, and methods of use. The medical kit may further include instructions for use.

Two or more blockstents100A-B may be used in combination to fill the lumen or void701of the blood vessel700, as illustrated inFIG. 26. Additionally, a second, third, or more blockstents may be required to fill the remaining portion of the blood vessel not filled by the first blockstent.

It will be appreciated that the devices and methods of the present invention are capable of being incorporated in the form of a variety of embodiments, only a few of which have been illustrated and described above. The disclosures herein may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the present invention is, therefore indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.