Embolic compositions and methods
Inventors
Groom, Jeffrey • WILTSEY, Craig • Pham, Quynh • MANSUKHANI, Nikhita • Guertin, Courtney • Core, Lee • Sharma, Upma
Assignees
Publication Number
US-11992576-B2
Publication Date
2024-05-28
Expiration Date
2041-06-09
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Abstract
The present disclosure pertains to crosslinkable compositions and systems as well as methods for forming crosslinked compositions in situ, including the use of the same for embolizing vasculature including the neurovasculature within a patient, among many other uses.
Core Innovation
The invention pertains to crosslinkable compositions and systems, as well as methods for forming crosslinked compositions in situ, particularly for embolizing vasculature including neurovasculature within a patient. The compositions are provided via kits containing a first fluid composition with a polysiloxane having two or more unsaturated groups and an imaging agent, a second fluid composition containing a hydride material with two or more hydride groups and an imaging agent, and a dry composition comprising at least one silica filler. When mixed, these components form a crosslinkable composition that cures into a solid in the body and occludes blood vessels.
A key problem addressed by the invention is the need for biocompatible, in-situ crosslinking materials that can completely fill and occlude blood vessels, including those that are difficult to access or have small diameters, and can be delivered with control and visibility using current clinical tools such as catheters. Existing materials may suffer from incomplete casting, high injection forces, limited penetration into distal branches, undesirable imaging properties, or biocompatibility concerns.
The disclosed compositions capitalize on the combination of polysiloxane polymers, hydride crosslinkers, imaging agents such as metal oxides, and silica fillers to achieve controlled rheology (including shear-thinning properties), even dispersion of the imaging agent, and efficient in situ curing. Methods include mixing and annealing fluid phases, dry incorporation of silica fillers, and injection by hand or catheter into the vasculature, where the material transitions from a flowable state to a solid, achieving vessel occlusion. These properties enable the compositions to be used in a range of vascular and neurovascular embolization scenarios.
Claims Coverage
The patent claims cover two main inventive features through its independent claims: a kit for forming crosslinkable compositions for vascular embolization, and a method for forming and delivering such compositions.
Kit for forming crosslinkable compositions for vascular embolization
A kit comprising: - A first fluid composition with a first polysiloxane having two or more unsaturated groups and a first imaging agent. - A second fluid composition containing a first hydride material with two or more hydride groups and a second imaging agent (which may be the same or different from the first). - A dry composition comprising a first silica filler and optionally a second silica filler (which may be the same or different from the first). The first fluid, second fluid, and dry composition are stable and, when mixed, form a crosslinkable composition with the imaging agents substantially evenly dispersed. Upon injection into a target vessel, the composition cures into a solid and occludes the vessel. Key inventive aspects include: - Stability and distinct separation of fluid and dry compositions until use. - Even dispersion of imaging agents upon mixing. - In situ curing and solidification for embolization. - Use of silica fillers to modulate physical properties.
Method of forming and delivering a crosslinkable composition for vascular embolization
A method comprising: 1. Annealing a first fluid composition containing a polysiloxane with two or more unsaturated groups and a first imaging agent. 2. Annealing a second fluid composition containing a hydride material with two or more hydride groups and a second imaging agent (same or different from the first). 3. At the time of use, mixing the first and second fluid compositions with a dry composition comprising a silica filler to form the crosslinkable composition, ensuring substantial even dispersion of imaging agents. 4. Injecting the crosslinkable composition into the vasculature of a patient, where it crosslinks and forms a solid to occlude the target vessel. The inventive method further specifies: - In situ mixing of dry and fluid components. - Formation of a shear-thinning, injectable composition suitable for hand injection or delivery via catheter. - Curing within the vasculature for complete occlusion.
In summary, the claims are directed toward a stable kit comprising specified fluid and dry compositions for in situ embolization, and a method focused on annealing, mixing, and delivering a crosslinkable, imaging-agent-dispersed composition for vascular occlusion.
Stated Advantages
Compositions provide complete casting and occlusion of targeted vasculature, including reaching small distal branches.
Enables injection by hand, requiring only clinically relevant force, facilitating ease of delivery and tactile feedback.
Shear-thinning properties allow deep, controlled penetration into vasculature while minimizing risk of non-target embolization.
Uniform dispersion of imaging agents ensures even radiopacity, permitting real-time fluoroscopic visualization during procedures.
Biocompatible, solvent-free materials minimize inflammation, vessel injury, and necrosis as evidenced by histopathology.
Formulations can be tailored for injection through a wide range of catheter sizes, including small lumens, supporting various clinical applications.
Crosslinked compositions are stable and can be terminally sterilized (e.g., by electron beam or ethylene oxide), supporting safe clinical use.
Documented Applications
Vascular embolization, including occlusion of arteries or veins for therapeutic purposes.
Neurovascular embolization procedures.
Portal vein embolization to increase size of future liver remnant before hepatic resection.
Embolization of tumors, including meningioma and peripheral tumors.
Pre-surgical embolization of tumors to minimize blood loss.
Treatment of chronic subdural hematoma.
Treatment of brain aneurysms, arteriovenous malformations, and arteriovenous fistulas.
Treatment of gastrointestinal bleeds and bleeding due to trauma.
Prostate artery embolization.
Uterine artery embolization.
Treatment of visceral aneurysms, varicoceles, and varices.
Treatment for pelvic congestion.
Treatment of epistaxis.
Treatment of endoleaks.
Injection into vasculature in conjunction with other devices such as coils, plugs, or stent grafts.
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