Vaso-occlusive devices with in-situ stiffening

#The disclosed inventions pertain generally to vaso-occlusive devices for establishing an embolus or vascular occlusion in a blood vessel. Specifically, the disclosed inventions pertain to systems and methods for in-situ stiffening of vaso-occlusive devices.

#Vaso-occlusive devices or implants are used for a wide variety of reasons, including treatment of intra-vascular aneurysms. Commonly used vaso-occlusive devices include soft, helically wound coils formed by winding a platinum (or platinum alloy) wire strand about a “primary” mandrel. The coil is then wrapped around a larger, “secondary” mandrel, and heat treated to impart a secondary shape. For example, U.S. Pat. No. 4,994,069, issued to Ritchart et al., which is fully incorporated herein by reference, describes a vaso-occlusive device that assumes a linear, helical primary shape when stretched for placement through the lumen of a delivery catheter, and a folded, convoluted secondary shape when released from the delivery catheter and deposited in the vasculature. Other vaso-occlusive devices having woven braids or embolic agents have been used in treatment of intra-vascular aneurysms.

#In order to deliver the vaso-occlusive devices to a desired site in the vasculature, e.g., within an aneurysmal sac, it is well-known to first position a small profile, delivery catheter or “micro-catheter” at the site using a steerable guidewire. Typically, the distal end of the micro-catheter will stay in a desired position for releasing one or more vaso-occlusive device(s) into the aneurysm once the guidewire is withdrawn. A delivery or “pusher” wire is then passed through the micro-catheter, until a vaso-occlusive device coupled to a distal end of the delivery wire is extended out of the distal end opening of the micro-catheter and into the aneurysm. Once in the aneurysm, the vaso-occlusive devices bend to allow more efficient and complete packing. The vaso-occlusive device is then released or “detached” from the end delivery wire, and the delivery wire is withdrawn back through the catheter. Depending on the particular needs of the patient, one or more additional occlusive devices may be pushed through the catheter and released at the same site.

#FIGS. 1A-B are perspective views of a vaso-occlusive device braid constructed according to various embodiments of the disclosed inventions.

#FIGS. 2A-E are perspective and cross-sectional views of a vaso-occlusive device braid constructed according to further embodiments of the disclosed inventions.

#FIGS. 3A-E are cross-sectional views of a vaso-occlusive coil constructed according to various embodiments of the disclosed inventions.

#For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

#All numeric values are herein assumed to be modified by the term “about,” whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the terms “about” may include numbers that are rounded to the nearest significant figure.

#The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).