Method for configuring an arteriovenous fistula
An embodiment of the invention relates to a method of configuring blood vessels at an anastomosis, the method comprising: ensheathing a segment of a transected first blood vessel in a lumen of a sleeve so that an open end of the segment protrudes from a sleeve end; suturing edges of an incision made in a second blood vessel to the open end of the first blood vessel to create an anastomosis; and sliding the sleeve along the first blood vessel to position the sleeve at the anastomosis.
1. An apparatus for configuring first and second blood vessels, wherein the first blood vessel is connected to a second blood vessel, creating a fistula, the apparatus comprising:
a coupler with a first side that seats on and couples to an external surface of the first blood vessel surrounding the fistula, the coupler including a lumen connecting the first side of the coupler at the fistula to a second side of the coupler; and
a sleeve having a lumen, a first end of the sleeve connecting to the second side of the coupler, thereby connecting the lumen of the sleeve and the lumen of the coupler, the lumen of the sleeve ensheathing at least a portion of the second blood vessel, wherein
the lumen of the coupler and the lumen of the sleeve together form a structure for holding the second blood vessel at a substantially constant angle with respect to the first blood vessel, and
the coupler is configured to impose a first constrained shape on the first blood vessel and the sleeve is configured to impose a second constrained shape on the second blood vessel, the first constrained shape having a first diameter (D 1 ) and the second constrained shape being inclusive of a conical segment with a diameter that increases continuously, as a function of distance from the fistula, from a second diameter (D 2 ) proximal to the fistula to a third diameter (D 3 ) distal from the fistula, wherein the first and second diameters are equal (D 1 =D 2 ) and a diameter ratio of the third to first diameters (D 3 :D 1 ) is in a range from about 1.2 to about 1.6.
2. The apparatus of claim 1 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is between about 20° and about 60°.
3. The apparatus of claim 1 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 40°.
4. The apparatus of claim 1 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 50°.
5. The apparatus of claim 1 , wherein the coupler is configured to impose a rounded contour to the first blood vessel and the second blood vessel, in proximity to the fistula.
6. The apparatus of claim 1 , wherein the first blood vessel is an artery and the second blood vessel is a vein.
7. The apparatus of claim 1 , wherein the diameter ratio (D 2 :D 1 ) is about 1.4.
8. An apparatus for configuring first and second blood vessels, wherein the first blood vessel is connected to a second blood vessel, creating a fistula, the apparatus comprising:
a coupler with a first side that seats on and couples to an external surface of the first blood vessel surrounding the fistula, the coupler including a lumen connecting the first side of the coupler at the fistula to a second side of the coupler; and
a sleeve having a lumen, a first end of the sleeve connecting to the second side of the coupler, thereby connecting the lumen of the sleeve and the lumen of the coupler, the lumen of the sleeve and the lumen of the coupler together ensheathing at least a portion of the second blood vessel, thereby forming a structure for holding the second blood vessel at a substantially constant angle with respect to the first blood vessel, wherein
the coupler is configured to impose a first constrained shape on the first blood vessel and the sleeve is configured to impose a second constrained shape on the second blood vessel, the first constrained shape having a first diameter (D 1 ) and the second constrained shape being inclusive of a conical segment with a diameter that increases continuously, as a function of distance from the fistula, from a second diameter (D 2 ) proximal to the fistula to a third diameter (D 3 ) distal from the fistula, wherein the first and second diameters are equal (D 1 =D 2 ) and a diameter ratio of the third to first diameters (D 3 :D 1 ) is in a range from about 1.2 to about 1.6.
9. The apparatus of claim 8 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is between about 20° and about 60°.
10. The apparatus of claim 8 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 40°.
11. The apparatus of claim 8 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 50°.
12. The apparatus of claim 8 , wherein the coupler is configured to impose a rounded contour to the first blood vessel and the second blood vessel, in proximity to the fistula.
13. The apparatus of claim 8 , wherein the first blood vessel is an artery and the second blood vessel is a vein.
14. The apparatus of claim 8 , wherein the diameter ratio (D 2 :D 1 ) is about 1.4.
15. A method for configuring first and second blood vessels, wherein the first blood vessel is connected to a second blood vessel, creating a fistula, the method comprising the steps of:
seating and coupling a first side of a coupler to an external surface of the first blood vessel surrounding the fistula, the coupler including a lumen connecting the first side of the coupler at the fistula to a second side of the coupler; and
connecting a first side of a sleeve having a lumen to the second side of the coupler, thereby connecting the lumen of the sleeve and the lumen of the coupler, the lumen of the sleeve ensheathing at least a portion of the second blood vessel, wherein
the lumen of the coupler and the lumen of the sleeve together form a structure for holding the second blood vessel at a substantially constant angle with respect to the first blood vessel, and
the coupler is configured to impose a first constrained shape on the first blood vessel and the sleeve is configured to impose a second constrained shape on the second blood vessel, the first constrained shape having a first diameter (D 1 ) and the second constrained shape being inclusive of a conical segment with a diameter that increases continuously, as a function of distance from the fistula, from a second diameter (D 2 ) proximal to the fistula to a third diameter (D 3 ) distal from the fistula, wherein the first and second diameters are equal (D 1 =D 2 ) and a diameter ratio of the third to first diameters (D 3 :D 1 ) is in a range from about 1.2 to about 1.6.
16. The method of claim 15 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is between about 20° and about 60°.
17. The method of claim 15 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 40°.
18. The method of claim 15 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 50°.
19. The method of claim 15 , wherein the coupler is configured to impose a rounded contour to the first blood vessel and the second blood vessel, in proximity to the fistula.
20. The method of claim 15 , wherein the diameter ratio (D 2 :D 1 ) is about 1.4.
21. A method for configuring first and second blood vessels, wherein the first blood vessel is connected to a second blood vessel, creating a fistula, the method comprising the steps of:
seating and coupling a first side of a coupler to an external surface of the first blood vessel surrounding the fistula, the coupler including a lumen connecting the first side of the coupler at the fistula to a second side of the coupler; and
connecting a first end of a sleeve having a lumen to the second side of the coupler, thereby connecting the lumen of the sleeve and the lumen of the coupler, the lumen of the sleeve and the lumen of the coupler together ensheathing at least a portion of the second blood vessel, thereby forming a structure for holding the second blood vessel at a substantially constant angle with respect to the first blood vessel, wherein
the coupler is configured to impose a first constrained shape on the first blood vessel and the sleeve is configured to impose a second constrained shape on the second blood vessel, the first constrained shape having a first diameter (D 1 ) and the second constrained shape being inclusive of a conical segment with a diameter that increases continuously, as a function of distance from the fistula, from a second diameter (D 2 ) proximal to the fistula to a third diameter (D 3 ) distal from the fistula, wherein the first and second diameters are equal (D 1 =D 2 ) and a diameter ratio of the third to first diameters (D 3 :D 1 ) is in a range from about 1.2 to about 1.6.
22. The method of claim 21 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is between about 20° and about 60°.
23. The method of claim 21 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 40°.
24. The method of claim 21 , wherein the substantially constant angle between the first blood vessel and the second blood vessel is about 50°.
25. The method of claim 21 , wherein the coupler is configured to impose a rounded contour to the first blood vessel and the second blood vessel, in proximity to the fistula.
26. The apparatus of claim 21 , wherein the diameter ratio (D 2 :D 1 ) is about 1.4.