# US 2025/0144281 A1 · Methods and systems for establishing retrograde carotid arterial blood flow > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0144281 A1 - Document ID: US20250144281A1 - Status: Published application - Kind: A1 - Application number: 19/016,406 - Filed: 2025-01-10 - Published: 2025-05-08 - Earliest claimed: 2007-07-18 - Assignees: Silk Road Medical, Inc. - Applicants: Silk Road Medical, Inc. - Inventors: Enrique Criado; Tony M. Chou; Michi E. Garrison; Gregory M. Hyde; Alan Schaer; Richard Renati - Web page: https://patentgrep.com/patent/US20250144281A1 ## CPC - A61M 1/3655: {Arterio-venous shunts or fistulae} - G11B 25/043: {using rotating discs} - A61B 8/06: Measuring blood flow - A61B 8/488: {involving Doppler signals} - A61B 17/12045: {double occlusion, e.g. during anastomosis} - A61B 17/12109: {in a blood vessel} - A61F 2/82: Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents (stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07) - A61F 2/95: Instruments specially adapted for placement or removal of stents or stent-grafts - A61M 1/34: Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration - A61M 1/36: Other treatment of blood in a by-pass of the natural circulatory system, e.g. temperature adaptation, irradiation {; Extra-corporeal blood circuits} - A61M 1/3613: {Reperfusion, e.g. of the coronary vessels, e.g. retroperfusion} - A61M 1/3659: {Cannulae pertaining to extracorporeal circulation} - A61M 5/007: {for contrast media} - A61M 25/10: Balloon catheters ({A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02;} inflatable balloons for placing stents or stent-grafts A61F2/958 {; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00}) - A61M 29/02: Dilators made of swellable material {(balloon catheters for angioplasty A61M25/104)} - A61M 39/06: Haemostasis valves, i.e. gaskets sealing around a needle, catheter or the like, closing on removal thereof - A61M 39/22: Valves or arrangement of valves {(A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405)} - G11B 5/4846: {Constructional details of the electrical connection between arm and support} - A61B 2017/00778: {Operations on blood vessels (A61B2017/22097, A61B2017/320741 take precedence)} - A61B 2017/12127: {Double occlusion, e.g. for creating blood-free anastomosis site} - A61B 2017/320716: {comprising means for preventing embolism by dislodged material} - A61F 2/90: characterised by a net-like or mesh-like structure - A61F 2/954: for placing stents or stent-grafts in a bifurcation - A61F 2002/065: {Y-shaped blood vessels} - A61F 2250/0037: differing in height or in length - A61M 2025/1052: {for temporarily occluding a vessel for isolating a sector} - A61M 2205/33: Controlling, regulating or measuring - A61M 2205/3331: Pressure; Flow - A61M 2205/3334: Measuring or controlling the flow rate - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract Interventional procedures on the carotid arteries are performed through a transcervical access while retrograde blood flow is established from the internal carotid artery to a venous or external location. A system for use in accessing and treating a carotid artery includes an arterial access device, a shunt fluidly connected to the arterial access device, and a flow control assembly coupled to the shunt and adapted to regulate blood flow through the shunt between at least a first blood flow state and at least a second blood flow state. The flow control assembly includes one or more components that interact with the blood flow through the shunt. ## Claims ### Claim 1 A system for treating a carotid artery, the system comprising: an arterial access sheath configured to be disposed within a carotid artery; a shunt coupled to the arterial access sheath; a flow control assembly coupled to the shunt, the flow control assembly configured to regulate flow through the shunt between a first flow state and a second flow state; and a venous return sheath coupled to the shunt, the venous return sheath being configured to be disposed within a vein. ### Claim 2 (depends on 1) The system of claim 1, wherein the first flow state is a low flow rate. ### Claim 3 (depends on 2) The system of claim 2, wherein the second flow state is a high flow rate. ### Claim 4 (depends on 1) The system of claim 1, further comprising an actuator for shifting the flow control assembly between the first flow state and the second flow state. ### Claim 5 (depends on 4) The system of claim 4, wherein the flow control assembly includes a second actuator for stopping flow through the flow control assembly. ### Claim 6 (depends on 1) The system of claim 1, wherein the flow control assembly includes a filter. ### Claim 7 (depends on 1) The system of claim 1, further comprising a sheath stopper tube disposed along the arterial access sheath. ### Claim 8 (depends on 7) The system of claim 7, wherein the sheath stopper tube has an angled distal end region. ### Claim 9 (depends on 7) The system of claim 7, wherein the sheath stopper tube has a flared proximal end region. ### Claim 10 (depends on 1) The system of claim 1, further comprising an adapter disposed adjacent to a proximal end of the arterial access sheath. ### Claim 11 (depends on 10) The system of claim 10, further comprising an extension tube coupled to the adapter and extending proximally therefrom. ### Claim 12 (depends on 1) The system of claim 1, further comprising a means for occluding a common carotid artery. ### Claim 13 (depends on 12) The system of claim 12, wherein the means for occluding a common carotid artery includes an occlusion element coupled to the arterial access sheath. ### Claim 14 (depends on 12) The system of claim 12, wherein the means for occluding a common carotid artery includes a separate occlusion device separate from the arterial access sheath. ### Claim 15 (depends on 1) The system of claim 1, further comprising a treatment catheter configured to be advanced through the arterial access sheath. ### Claim 16 A reverse flow system for treating a carotid artery, the system comprising: an arterial access sheath configured to be disposed within a carotid artery; a venous return sheath, the venous return sheath being configured to be disposed within a vein so as to establish reverse flow of blood from the carotid artery through the arterial access sheath and into the vein via the venous return sheath; and a flow control assembly disposed between and coupled to both the arterial access sheath and the venous return sheath, the flow control assembly configured to regulate flow of blood from the arterial access sheath toward the venous return sheath. ### Claim 17 (depends on 16) The system of claim 16, further comprising a sheath stopper tube disposed along the arterial access sheath. ### Claim 18 (depends on 17) The system of claim 17, wherein the sheath stopper tube has an angled distal end region. ### Claim 19 (depends on 17) The system of claim 17, wherein the sheath stopper tube has a flared proximal end region. ### Claim 20 A reverse flow system for treating a carotid artery, the system comprising: an arterial access sheath configured to be disposed within a common carotid artery; a venous return sheath configured to be disposed within a vein; and a flow control assembly coupled to the arterial access sheath and coupled to the venous return sheath, the flow control assembly configured to regulate flow of blood from the arterial access sheath to the venous return sheath.