Ultrasonic crimping of a varied diameter vascular graft

1. A method of crimping a varied diameter graft comprising:

(a) providing a flat-woven tubular graft having an enlarged woven bulbous portion disposed between flat-woven tubular ends, wherein the flat-woven diameter of said woven bulbous portion is greater than the flat-woven diameters of said tubular ends;

(b) providing a mandrel shaped and sized to said woven bulbous portion and having a curved crimping surface;

(c) positioning said curved crimping surface within said woven bulbous portion so that said woven bulbous portion contours to said curved crimping surface;

(d) providing a horn having a crimped surface mateable to said crimped surface of said mandrel;

(e) aligning said crimping surface of said horn over said woven bulbous portion;

(f) securing said woven bulbous portion between said crimping surface of said horn and said crimping surface of said mandrel;

(g) causing said woven bulbous portion to heat by ultrasonic action from said horn to heat set crimps thereat; and

(h) rotating said graft around said mandrel and repeating steps (e) through (g) until the graft is circumferentially crimped.

2. The method of claim 1 , further comprising heating said woven bulbous portion to set a bulbous shape of said woven bulbous portion.

3. The method of claim 2 , further comprising applying pressure to said woven bulbous portion to set a bulbous shape of said woven bulbous portion.

4. The method of claim 2 , wherein said heating is caused by ultrasonic action.

5. The method of claim 1 , wherein step (f) further comprises applying pressure between said crimping surface of said horn and said crimping surface of said mandrel.

6. The method of claim 5 , where said pressure is from about 10 psi to about 100 psi.

7. The method of claim 1 , wherein said horn operates at a frequency of 20 kHz, 30 kHz, or 40 kHz.

8. A method of crimping a varied diameter graft comprising:

(a) providing a flat-woven tubular graft having an enlarged woven bulbous portion disposed between flat-woven tubular ends, wherein the flat-woven diameter of said bulbous portion is greater than the flat-woven diameters of said tubular ends;

(b) providing a rotatable mandrel shaped and sized to said woven bulbous portion and having a curved crimping surface;

(c) positioning said curved crimping surface of said rotatable mandrel within said woven bulbous portion so that said woven bulbous portion contours to said curved crimping surface;

(d) providing a rotatable horn having a crimped surface mateable to said crimped surface of said rotatable mandrel made to rotate;

(e) aligning said crimping surface of said rotatable horn over said woven bulbous portion;

(f) securing said woven bulbous portion between said crimping surface of said rotatable horn and said curved crimping surface of said rotatable mandrel; and

(g) causing said woven bulbous portion to heat by ultrasonic action from said horn to heat set a bulbous shape of said woven bulbous portion and to heat set crimps thereat.

9. The method of claim 8 , wherein step (f) further comprises applying an impingement force between said crimping surface of said rotatable horn and said crimping surface of said rotatable mandrel.

10. The method of claim 9 , wherein the impingement force is at a pressure from about 10 psi to about 100 psi.

11. The method of claim 8 , wherein said crimps are radially extending crimps.

12. The method of claim 8 , wherein said rotatable horn operates at a frequency of 20 kHz, 30 kHz, or 40 kHz.

13. The method of claim 8 , further comprising rotating said rotatable horn and said rotatable mandrel around the graft and repeating steps (e) through (g) until the graft is circumferentially crimped.