US-12622703-B2 - Coils used in intravascular treatment

US12622703B2US 12622703 B2US12622703 B2US 12622703B2US-12622703-B2

Abstract

A complex coil for intravascular treatment, a mandrel for constructing the complex coil, and the method for constructing the complex coil is disclosed. The coil generally comprises a primary wire formed to a primary spring and then formed to a secondary three dimensional shape, wherein the primary spring forms a secondary set of layers of successive loops. A fixed number of loops define a layer forming a locus of points enclosing a generally spherical surface and forming a repeatable pattern, the second successive layer of loops of the repeatable pattern being generally larger in diameter and spherical size than the previous layer. The locus of the points from the four or more loops define an enclosed spheroid adapted to fill or frame an embolism wherein the size and geometry of the successive loops can be manipulated by various means of the unique design of the mandrel.

Inventors

David A. Watson

Assignees

David A. Watson

Dates

Publication Date: 20260512
Application Date: 20230525

Claims (7)

1 . An embolic coil for intravascular treatment formed from a wire, and when deployed comprises: multiple non-parallel faces with each face formed by multiple layers of loops of the wire, the multiple layers of loops of each face including a first loop of a first layer and a second loop of a second layer, each of the first and second loops comprising linear elements connected by non-linear elements.
2 . The embolic coil of claim 1 , wherein each of the first and second loops is a substantially triangular loop.
3 . The embolic coil of claim 1 , wherein the first loop has a first circumference different than a second circumference of the second loop.
4 . The embolic coil of claim 1 , wherein the first loop precedes the second loop and has a first circumference larger than a second circumference of the second loop.
5 . The embolic coil of claim 1 , wherein all of the multiple layers of loops of each face comprises linear segments connected by non-linear segments.
6 . The embolic coil of claim 1 , wherein each of the multiple layers of loops of each face is a substantially triangular loop.
7 . An embolic coil for intravascular treatment formed from a wire and when deployed comprises: multiple non-parallel faces that are each formed by a single substantially triangular loop comprising linear segments connected by non-linear segments.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63/346,775, filed May 27, 2022, the content of which is incorporated by reference herein in its entirety. BACKGROUND The present invention relates generally to implantable devices for interventional therapeutic treatment and vascular surgery, and more particularly to a therapeutic device in the form of an embolic or vasoocclusive coil deployable within a patient's vasculature, and a mandrel for making a novel coil structure. The art and science of interventional therapy and surgery has continually progressed in the treatment of vascular defects and diseases by the use of ever smaller incisions or access through the vasculature or body openings in order to reduce the trauma to tissue surrounding the treatment site. One important aspect of such treatments involves the use of catheters to place therapeutic devices at a treatment site by access through the vasculature. Examples of such procedures include transluminal angioplasty, placement of stents to reinforce the walls of a blood vessel, and the use of vasoocclusive devices to treat defects or weaknesses in the vasculature. One specific field of interventional therapy that has been able to advantageously use recent developments in technology is the treatment of neurovascular defects. As smaller and more capable structures and materials are developed, treatment of vascular defects in the human brain that were previously untreatable or presented an unacceptable risk via conventional surgery have become more amenable to treatment thanks to these advances. One type of therapy that has become advantageous for the treatment of defects in the neurovasculature is the catheter placement of vasoocclusive devices such as embolic coils into a damaged portion of a vein or artery. Vasoocclusive devices are therapeutic devices that form an embolus to block or restrict the flow of blood through a vessel or to prevent blood from entering an aneurysm in the vessel. One such vasoocclusive device widely used for this purpose is a helical wire coil that transforms in a deployed configuration to a three dimensional shape to engage the walls of an aneurism. Vasoocclusive devices are designed to conform with the shape of an aneurysm and are made of a pre-formed strand of material such as a platinum-tungsten alloy. US Patent Publication No. 2009/0297582, the content of which is incorporated herein by reference, describes some examples of materials suitable for embolic coils. These vasoocclusive devices comprise one or more vasoocclusive strands wound in a manner so as to form a generally spherical or ovoid shape in its deployed state. The strand is typically first helically wound in a generally linear fashion, and then wound around an appropriately shaped mandrel, and then heat treated to impart the shape of the mandrel after its removal. Radiopacity may be provided by the natural radiopacity of a platinum alloy wire when so constructed. The coils can take a variety of configurations, and may generally be characterized as either ‘framing coils’ or ‘filling coils.’ Framing coils are intended to have a stiffer, more robust shape that approximates the size of the defect (i.e., having the aneurysm's diameter), whereas filling coils tend to be less rigid and function to occupy the spaces left within the voids formed by the previously deployed framing coil(s). In a preferred embodiment of the present invention, a unique mandrel defined herein may be used for creating a framing coil, and also be used to produce a complimentary filling coil with only a minor variation of the technique used in winding the primary strand onto the mandrel. The delivery of such vasoocclusive devices may be accomplished by a variety of means, including via a catheter whereby the coil device is pushed through the patient's vasculature and deployed in the treatment location. The coil may be releasably attached to the pusher element and a variety of detachment mechanisms are available to release the device from the pusher. As stated above, aneurysm framing coils are intended to engage aneurysms that may be somewhat spheroid in shape. Framing coils are formed by shaping a primary wind of coil (generally ⅓ to ½ mm in diameter) into a three dimensional pattern that has a mean diameter in some neurovascular applications ranging from about 2 mm to 20 mm. “Framing” refers to the practice where the first coil (and sometimes subsequent coils) is placed inside the aneurysm and the coil is allowed to unfold from its more linear helical configuration on the delivery catheter to a generally spheroidal shape matching the interior of the aneurysm. For this reason, framing coils are designed and specified to treat a specific diameter aneurysm. A ten millimeter framing coil is thus designed to treat an aneurysm having an approximate shape of a ten millimeter diameter sphere, where care is taken to prevent the coil f