Compound barb medical device and method
Barbed medical devices include a crown interconnecting a pair of legs and at least one barb extending from each of the legs. The at least one barb may define an inner surface with a first portion disposed at a first orientation relative to a longitudinal axis of the leg, a second portion disposed at a second orientation relative to the longitudinal axis, and optionally, a third portion disposed at a third orientation relative to the longitudinal axis of the leg.
1. A method of forming a compound barb on a staple comprising:
providing a staple having a pair of legs, each leg defining a longitudinal axis; and
applying vibrational energy to a cutting element to form a compound barb on at least a portion of each leg including:
forming a first cut in the leg, the first cut having a first ratio of cut depth to diameter of the leg; and
forming a second cut in the leg, the second cut having a second ratio of cut depth to diameter of the leg.
2. The method according to claim 1 , further comprising forming a third cut in the leg, the third cut having a third ratio of cut depth to diameter of the leg.
3. The method according to claim 1 , wherein the first ratio is approximately 1% to about 40%.
4. The method according to claim 1 , wherein the second ratio is approximately 5% to about 50%.
5. The method according to claim 2 , wherein the third ratio is approximately 15% to about 50%.
6. The method according to claim 1 , wherein the compound barb on at least a portion of each leg defines an inner surface having a complementary shape with an outer surface of the leg, the inner surface including a first portion disposed at a first orientation relative to a longitudinal axis of the leg and a second portion disposed at a second orientation relative to the longitudinal axis.
7. The method according to claim 6 , wherein an inner surface of the compound barb further comprises a third portion disposed at a third orientation relative to the longitudinal axis.
8. The method according to claim 7 , wherein at least one of the first, second, and third portions is substantially linear.
9. The method according to claim 7 , wherein at least one of the first, second, and third portions are at first, second, and third angles relative to respective longitudinal axes of each leg.
10. The method according to claim 9 , wherein the first angle is about 0 degrees to about 90 degrees.
11. The method according to claim 10 , wherein the first angle is about 30 degrees to about 40 degrees.
12. The method according to claim 11 , wherein the first angle is about 31 degrees to about 38 degrees.
13. The method according to claim 9 , wherein the second angle is about 0 degrees to about 90 degrees.
14. The method according to claim 13 , wherein the second angle is from about 1 degree to about 10 degrees.
15. The method according to claim 14 , wherein the second angle is from about 2 degrees to about 8 degrees.
16. The method according to claim 9 , wherein the third angle is about 0 degrees to about 90 degrees.
17. The method according to claim 7 , wherein at least one of the first, second, and third portions is substantially non-linear.
18. The method according to claim 17 , wherein the substantially non-linear portion is cut at a radius relative to the longitudinal axis of the leg.