Methods and systems for establishing retrograde carotid arterial blood flow
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.
1. A method for treating a carotid artery, comprising:
forming penetration in a wall of a common carotid artery via a transcervical incision, the penetration being located at distance of around 5 cm to 7 cm below a bifurcation location where the patient's common carotid artery bifurcates into an internal carotid artery and external carotid artery;
positioning an arterial access sheath through the transcervical incision and into the common carotid artery, wherein the arterial access sheath has a working length of 5 cm to 15 cm, wherein the access sheath includes an expandable element;
inserting no more than the working length of the arterial access sheath into the common carotid artery;
expanding the expandable element so that the expandable element blocks blood flow through the common carotid artery past the sheath and establish retrograde blood flow through the internal carotid artery and into the sheath, wherein blood flows into a shunt of the sheath while the common carotid artery remains blocked;
actively assisting blood flow from the common carotid artery into the sheath and into the shunt;
flowing the blood from the shunt to a return location.
2. A method as in claim 1 , further comprising adjusting the flow rate of blood flow through the shut.
3. A method as in claim 2 , wherein the flow rate is controlled over a range from a low rate to a high rate, where the high rate is at least three fold higher than the low rate.
4. A method as in claim 3 , wherein the high rate is at least five fold higher than the low rate.
5. A method as in claim 2 , wherein flow rate is controlled at a baseline low flow rate in the range from 10 ml/min to 200 ml/min during a majority of a procedure.
6. A method as in claim 2 , wherein the flow rate is increased to a higher rate when there is an increased risk of emboli release.
7. A method as in claim 2 , wherein the procedure comprises stenting of the internal carotid artery and the flow rate is increased during at least one of when a stent delivery catheter is introduced to the carotid artery, when the stent is deployed in the carotid artery, when the stent delivery catheter is removed from the carotid artery, or when the common carotid artery occlusion is released.
8. A method as in claim 2 , wherein the flow rate is increased automatically.
9. A method as in claim 1 , wherein actively assisting blood flow comprises fluidly attaching the shunt to a pump.
10. A method as in claim 1 , wherein actively assisting blood flow comprises fluidly attaching the shunt to a vacuum source.