Methods and systems for establishing retrograde carotid arterial blood flow

A method for accessing and treating a carotid artery, comprising:

• forming a penetration in a wall of a common carotid artery;
• positioning an arterial access sheath through the penetration;
• blocking blood flow from the common carotid artery past the sheath;
• allowing retrograde blood flow from the internal carotid artery into the sheath and into a shunt from the sheath while the common carotid artery remains blocked;
• and
• adjusting the state of retrograde blood flow through the shunt, wherein adjusting comprises adjusting flow resistance from the arterial access sheath to a return site by causing blood to flow through a flow resistance element coupled to the shunt, wherein the flow resistance element comprises two or more parallel flow paths of the shunt and a valve to open or close one or more of the flow paths to selectively direct blood flow through one or more of the flow paths.

A method for accessing and treating a carotid artery, comprising:

• forming a transcervical incision in a neck of a patient;
• forming a penetration in a wall of a common carotid artery;
• inserting a distal section of the arterial access sheath through the transcervical incision and the penetration, wherein the arterial access sheath includes a removable stopper member that covers a portion of the distal section of the sheath such that a portion of the distal section of the sheath is covered by the stopper member and a portion of the distal section of the sheath is exposed, wherein the stopper member, when coupled to the sheath, limits insertion of the sheath into the carotid artery to the exposed portion;
• inserting no more than the exposed portion of the sheath into the common carotid artery;
• blocking blood flow from the common carotid artery past the sheath;
• allowing retrograde blood flow from the internal carotid artery into the sheath and into a shunt from the sheath while the common carotid artery remains blocked;
• and
• adjusting the state of retrograde blood flow through the shunt using a flow control element attached directly to the shunt.