Embolic compositions and methods
Inventors
Groom, Jeffrey • WILTSEY, Craig • Pham, Quynh • MANSUKHANI, Nikhita • Guertin, Courtney • Core, Lee • Sharma, Upma
Assignees
Publication Number
US-12053560-B2
Publication Date
2024-08-06
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 provides crosslinkable biocompatible compositions, systems, and methods for the in situ formation of crosslinked materials. Central to the disclosure are compositions that can be delivered to specific body sites, such as the vasculature, including neurovasculature, where they crosslink to form solids. These compositions typically include a polysiloxane having two or more unsaturated groups, a hydride material having two or more hydride groups, one or more silica fillers, and one or more imaging agents that may serve as radiopaque materials. At least one component includes a catalyst to catalyze the crosslinking reaction between unsaturated and hydride groups.
The disclosed kits and methods address challenges associated with biomedical delivery of in-situ forming crosslinked compositions, such as delivering materials to closed or difficult-to-access cavities, achieving complete filling and support of surrounding tissues, and supporting flow-responsive behavior valuable for vascular embolization. By allowing mixing of fluid and dry components, as well as preparation steps such as annealing, the invention enables formation of crosslinkable compositions optimized for injectability, flow control, and imaging. Various embodiments ensure the compositions have properties like shear-thinning, controlled gel time, and radiopacity for visualization.
A key problem solved is the effective and controllable embolization of vasculature, particularly achieving deep distal penetration and complete occlusion of complex vessel networks while maintaining ease of injection and minimizing risks such as vessel constriction, reflux, and recanalization. The compositions are shown to adapt their viscosity in response to local flow conditions, ensuring precise casting and occlusion of target vessels. The technology also enables the user to tailor formulation parameters, mixing modes, and delivery devices (including balloon catheters) to optimize the embolization procedure for specific clinical needs, such as tumor embolization or treatment of chronic subdural hematoma.
Claims Coverage
The claim coverage includes one independent claim, which delineates several inventive features central to methods for vascular embolization using specifically prepared crosslinkable compositions.
Preparation of crosslinkable polysiloxane-based compositions
The method involves forming a crosslinkable composition by: 1. **Providing a first fluid composition** containing: - A polysiloxane with two or more unsaturated groups. - A first imaging agent with an average primary particle size of 80 nm to 200 nm. 2. **Providing a second fluid composition** containing: - A hydride material having two or more hydride groups. - A second imaging agent with an average primary particle size of 80 nm to 200 nm. 3. **Mixing the two fluid compositions with a dry composition** that comprises: - A first silica filler. - Optionally, a second silica filler that is the same as or different from the first. The result is a crosslinkable composition where the imaging agents and silica fillers are substantially evenly dispersed.
Injecting the crosslinkable composition for vascular occlusion
The method includes preparing the crosslinkable composition for injection and injecting it into an injection site within the vasculature of a patient. Upon injection, the composition substantially flows into and occludes a plurality of distal vessels, including at least one vessel with a diameter of less than 100 microns, and then crosslinks to form a solid to achieve occlusion.
The inventive features collectively establish a robust, reproducible method of preparing and applying specialized crosslinkable compositions—encompassing particular polysiloxanes, hydride materials, silica fillers, and imaging agents—for effective, flow-responsive vascular embolization capable of deep distal vessel penetration and solid in situ formation.
Stated Advantages
The crosslinkable compositions facilitate delivery to closed or difficult-to-access body sites, including intravascularly, and are capable of filling empty, potential, or blood-filled spaces while supporting surrounding tissues.
The compositions exhibit shear-thinning properties, enabling microcatheter injection and responsive flow for distal vascular penetration and proximal control during reduced flow.
Radiopaque or otherwise imageable compositions allow real-time visualization and precise placement during procedures.
The materials adapt viscosity in response to flow conditions, enhancing the ability to deeply penetrate distal vasculature and form complete vessel casts, achieving solid occlusion.
The crosslinkable materials can be injected by hand and have tunable injection force, simplifying clinical procedures.
The compositions can be terminally sterilized using modalities such as e-beam or ethylene oxide, enhancing clinical safety.
Use of hydrophobic or hydrophilic silica fillers and various preparation methods provides formulation stability and allows tuning of coalescence, ductility, and structure.
The cured compositions are biocompatible and minimize vessel injury, necrosis, or severe inflammation upon implantation.
Documented Applications
Occlusion of the vasculature for treatment of tumors, including tumor embolization and pre-surgical embolization to minimize blood loss.
Treatment of chronic subdural hematoma.
Embolization procedures for brain aneurysms, arteriovenous malformations, and arteriovenous fistulas.
Treatment of gastrointestinal bleeds, bleeding due to trauma, and hemorrhage.
Prostate artery embolization and uterine artery embolization.
Treatment of visceral aneurysms, varicoceles, varices, pelvic congestion, epistaxis, and endoleaks.
Portal vein embolization procedures and treatment of diseases involving the middle meningeal artery.
Use in conjunction with devices such as occlusion balloons, coils, plugs, or stent grafts for targeted delivery and enhanced vascular occlusion.
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