Arteriogeneses

Have two questions.

1. My vascular surgeon want to perform an aortabifemorl bypass.  The Radiologist posted the following results and conclusion: "The proximal abdominal aorta U shows very minimal atherosclerotic disease.  The celiac origin, SMA and bilateral single renal arteries are widely patent. There is complete occlusion of the infrarenal abdominal aorta
approximately 2.5 cm below the renal arteries. The external iliac arteries are reconstituted bilaterally. Runoff below the common femoral arteries is normal bilaterally.
CONCLUSION: Complete occlusion at the infrarenal abdominal aorta 2.5 cm
below the renal arteries consistent with Leriche syndrome.

I noticed on my CTA Aorta runout I have Arteriogeneses bilaterally on both illiac and femoral arteries.  Would exercising to increase the blood flow thought these collateral arteries be better that having the bypass surgery?  I am not looking to run a marathon and I am currently able to golf 2 rounds each weekend with a cart.. I am happy with my current limitations... Surgery stats give a 5% death rate and then a 25% possiblility of infection in the first two years from the graft material.

Also, is there any specific exercises to increase the efficiency of the existing collateral arteries?