BACKGROUND OF THE INVENTION

Embolic or occlusive coils are commonly used to occlude a target structure within a patient to prevent blood flow to the region. These coils are used to treat a variety of conditions, such as aneurysms. Treating aneurysms with coils involves filling the aneurysm with a length of coil, which becomes wadded up within the aneurysm, thus limiting open space within the aneurysm into which blood can flow. By limiting blood flow, the walls of the aneurysm are not subjected to potentially dangerous blood pressures. Additionally, blood clots are less likely to form and later escape through the neck of the aneurysm.

An aneurysm typically has a neck and a cavity, much like a balloon, and the embolic coil delivery procedure is complicated due to the variance in aneurysm sizes and shapes. It is important to completely fill the cavity with one or more coils and often several coils are required. If the cavity is not completely filled, the efficacy of the treatment is diminished, and the aneurysm will still be subjected to high blood pressures and may rupture. If too many coils are used, the coils will not remain contained within the aneurysm and may either migrate out of the aneurysm into the blood stream or begin to protrude from the neck of the aneurysm and impede blood flow through the adjoining vessel.

Coils that can be customized during implantation such that an ideal length can be created for any given aneurysm have been developed. These solutions are shown and described in U.S. Pat. No. 9,877,729 entitled CATHETER SYSTEM, issued on Jan. 30, 2018 to Bowman et al., and in U.S. Pat. No. 9,808,599, entitled DEVICE DELIVERY SYSTEM, issued Nov. 7, 2017 to Bowman et al., all of which are hereby incorporated by reference in their entireties.

During delivery of these coils, alignment between the electrical terminals of the delivery catheters, and the corresponding electrical contacts associated with the coils, is necessary to cause separation of the coil segments. Due to the small size of the coils, this alignment spans a short longitudinal distance. It would be beneficial to modify the electrical contacts associated with the coils and/or the electrical terminals on the delivery catheter to make alignment more forgiving.

Additionally, visualization of the coil length during delivery can be challenging. Traditionally, radiopaque and biocompatible materials are necessary to use under fluoroscopy during endovascular treatment of aneurysms and other vascular diseases. Materials such as platinum, palladium and tantalum ore often used to provide a clear visualization of the implant during the procedure. However, when there are already multiple implants inside the aneurysm, the proximal end of the implant can become difficult to visualize among the mass of equally dense radiopaque implants.

It would thus be beneficial to provide an implant and a delivery system that have areas of varying radiopacity and/or radiotransparency such that various details of the implant and delivery system may be visualized under radio imaging such as fluoroscopy.

OBJECTS AND SUMMARY OF THE INVENTION

The present invention is directed to a variable detachment coil having multiple detachment junctions so that a user can detach a customizable length of the coil to occlude a treatment site.

One aspect of the variable length detachment coil is an improved electrical contact configuration associated with the coil.

In one embodiment the, contacts comprise electrical bumps on the coils that make electrical contact with the terminals of the delivery catheter.

In another embodiment, the contact comprises whisker-like electrical leads that radiate from the coils.

Another aspect of the invention is a visualization system incorporated into the coils that comprise radiotransparent ceramic discs that appear as spaces in the coil segments under X-ray. These discs allow visualization of the individual coil segments.

Another aspect of the invention is directed to a coil having multiple detachment points, each of which have a radiopaque and/or radiotransparent quality that allows a physician to visualize the various detachment points, so a selection is more easily made.

In one embodiment the variable length detachable coils have electrical contacts that are filaments extending from the coil segments.

In another embodiment the variable length detachable coils have electrical contacts that are beads protruding outwardly from the coil segments.

