Ultrasonic surgical shears and method for sealing a blood vessel using same

1. A method for sealing a blood vessel of a patient comprising the steps of:

a) obtaining an ultrasonic surgical shears including an ultrasonic surgical blade, a clamping arm operable to open and close toward the blade, a tissue pad attached to the clamping arm, means for providing a clamp force and means for limiting a user applied clamp force, wherein the blade and tissue pad define a clamping surface area so that the applied clamp force does not exceed a clamping pressure of 210 psi at the clamping surface area;

b) disposing the blood vessel between the blade and the tissue pad;

c) operating the clamping arm to exert a predetermined average coaptation pressure on the blood vessel between and including 60 psi and 210 psi; and

d) ultrasonically vibrating the blade to transect and seal the blood vessel.

2. The method of claim 1 , wherein the average coaptation pressure in step c) is between and including 120 psi and 180 psi.

3. The method of claim 2 , wherein the average coaptation pressure in step c) is substantially 150 psi.

4. The method of claim 1 , wherein the blood vessel has an outside diameter larger than substantially 3 mm.

5. The method of claim 4 , wherein the blood vessel has an outside diameter between and including 4.5 mm and 5.0 mm.

6. The method of claim 4 , wherein the blood vessel has an outside diameter between and including 5.0 mm and 7.0 mm.

7. The method of claim 1 , wherein the clamping surface area is substantially 0.033 square inches.

8. The method of claim 7 , wherein step c) exerts a clamping force on the clamping arm between and including 2 pounds and 7 pounds.

9. The method of claim 1 , wherein the blade has a portion which opposes the tissue pad and which has a substantially square transverse cross section with a rounded edge defining a clamping surface area, wherein the tissue pad has a substantially rectangular transverse cross section, wherein the clamping surface area faces substantially toward the tissue pad, and wherein step b) disposes the blood vessel between the clamping surface area and the tissue pad.

10. The method of claim 1 , wherein the means for providing a clamp force is a motor.

11. The method of claim 1 , wherein the means for providing a clamp force is a spring.

12. An ultrasonic surgical shears comprising:

a) an ultrasonic surgical blade;

b) a clamping arm operable to open and close toward the blade;

c) a tissue pad attached to the clamping arm;

d) means for exerting a predetermined clamping force on the clamping arm, wherein the blade and tissue pad define a clamping surface area so that the clamp force does not exceed a clamping pressure of 210 psi at the clamping surface area; and

e) means for limiting a user applied clamping force.

13. The ultrasonic surgical shears of claim 12 , wherein the average clamping pressure is between and including 120 psi and 180 psi.

14. The ultrasonic surgical shears of claim 13 , wherein the average clamping pressure is substantially 150 psi.

15. The ultrasonic surgical shears of claim 12 , wherein the clamping surface area is substantially 0.033 square inches.

16. The ultrasonic surgical shears of claim 15 , wherein the clamping force is between and including 2 pounds and 7 pounds.

17. An ultrasonic surgical shears comprising:

a) an ultrasonic surgical blade;

b) a clamping arm operable to open and close toward the blade;

c) a tissue pad attached to the clamping arm, wherein the blade and tissue pad define a clamping surface area so that the applied clamp force does not exceed a clamping pressure of 210 psi at the clamping surface area; and

d) means for limiting a user applied clamping force on the clamping arm creating an average predetermined clamping pressure between and including 60 psi and 210 psi on tissue disposed between the tissue pad and the blade.

18. The ultrasonic surgical shears of claim 17 , wherein the average clamping pressure is between and including 120 psi and 180 psi.

19. The ultrasonic surgical shears of claim 18 , wherein the average clamping pressure is substantially 150 psi.

20. The ultrasonic surgical shears of claim 17 , wherein the clamping surface area is substantially 0.033 square inches.

21. The ultrasonic surgical shears of claim 20 , wherein the clamping force is between and including 2 pounds and 7 pounds.

22. A method for sealing a blood vessel of a patient comprising the steps of:

a) obtaining an ultrasonic surgical shears including an ultrasonic surgical blade, a clamping arm operable to open and close toward the blade, and a tissue pad attached to the clamping arm, wherein the blade and tissue pad define a clamping surface area so that the applied clamp force does not exceed a predetermined clamping pressure of 210 psi at the clamping surface area;

b) disposing the blood vessel between the blade and the tissue pad;

c) limiting the clamping arm to exert between and including 60 psi and 210 psi on the blood vessel; and

d) ultrasonically vibrating the blade to transect and seal the blood vessel.

23. A method for sealing a blood vessel of a patient comprising the steps of:

a) obtaining an ultrasonic surgical shears including an ultrasonic surgical blade, a clamping arm operable to open and close toward the blade, and a tissue pad attached to the clamping arm, wherein the blade and tissue pad define a predetermined clamping surface area so that the applied clamp force does not exceed a clamping pressure of 210 psi at the clamping surface area;

b) disposing the blood vessel between the blade and the tissue pad;

c) limiting the clamping arm to exert between and including 60 psi and 210 psi on the blood vessel; and

d) ultrasonically vibrating the blade to transect and seal the blood vessel for no more than 4.5 secs.