METHODS AND APPARATUS FOR STIMULATING STRETCH RECEPTORS IN THE VASCULATURE
Stimulation of a stretch receptor response to the cardiac cycle is enhanced by constraining a region of a blood vessel wall upstream and/or downstream of a baroreceptor. The constraint may be external or internal and will typically be effected using a circumferential restraint placed over or within the blood vessel.
1 . A method for enhancing stimulation of a stretch receptor in a vascular wall, said method comprising:
identifying a region in a patient's vasculature proximate a target stretch receptor; and
constraining a portion of a blood vessel wall upstream or downstream of the target stretch receptor;
wherein volume displacement during systole is inhibited in the contrained portion and increased the target region relative to volume displacement in the absence of such constraining.
2 . A method as in claim 1 , further comprising selecting a patient diagnosed with at least one of hypertension, congestive heart failure, and renal disease.
3 . A method as in claim 1 , wherein the stretch receptor comprises a baroreceptor.
4 . A method as in claim 3 , wherein the stretch receptor is disposed in a carotid artery or an aortic arch.
5 . A method as in claim 1 , wherein constraining comprises placing a circumferential restraint over an exterior of the blood vessel wall.
6 . A method as in claim 5 wherein the constraint has inelastic properties.
7 . A method as in claim 5 , wherein the constraint has elastic properties.
8 . A method as in claim 1 , wherein constraining comprises placing a circumferential restraint on an internal wall of the blood vessel.
9 . A method as in claim 8 , wherein the constraint has inelastic properties.
10 . A method as in claim 8 , wherein the constraint has elastic properties.
11 . A method as in claim 1 , wherein the blood vessel wall is constrained over an axial length in the range from 0.5 mm to 5 mm.
12 . A method as in claim 1 , wherein the blood vessel wall is constrained at at least one location upstream and at at least one location downstream of the target region.
13 . A method as in claim 1 , wherein the blood vessel wall is constrained at at least one location external to the blood vessel wall and at least one location internal to the blood vessel wall.
14 . A method as in claim 5 , further comprising adjusting the circumferential length of the restraint after it has been placed.
15 . Apparatus for stimulating a stretch receptor, said apparatus comprising:
a blood vessel wall expansion constraint adapted to be positioned over or within a portion of a blood vessel wall upstream or downstream of a stretch receptor in said blood vessel wall.
16 . Apparatus as in claim 15 , wherein the constraint comprises a circumferential restraint.
17 . Apparatus as in claim 16 , wherein the circumferential restraint is adapted to be placed over the blood vessel wall.
18 . Apparatus as in claim 16 , wherein the circumferential restraint is adapted to be placed internally and secured to an interior region of the blood vessel wall.
19 . Apparatus as in claim 16 , wherein the restraint has inelastic properties.
20 . Apparatus as in claim 16 , wherein the constraint has elastic properties.
21 . Apparatus as in claim 16 , wherein the constraint has an axial length in the range from 0.5 mm to 5 mm.
22 . Apparatus as in claim 16 , wherein the constraint has a circumferential length in the range from 3 mm to 30 mm.
23 . Apparatus as in claim 22 , wherein the constraint is adjustable.
24 . Apparatus as in claim 23 , wherein the length is remotely adjustable after implementation.