How long does surgery on vericose veins last is there a way to keep them from returning?

Depends. There is no magic bullet for varicose veins. You should see a specialist in venous disorders. Please understand that long term follow up and care of the varicose veins and venous insufficiency is the key to having good outcomes as opposed to a single type of procedure.
Yes. Get ultrasound scan of legs every year; wear medical compression stockings everyday for prolonged sitting and standing; have veins diagnosed and treated; annual treatment rants can prevent varicose veins; see a phlebologist.
No. Unfortunately, the major cause of varicose veins is your heredity. That means, no matter how effective your treatment might have been, eventually new varicose veins will develop. Studies have shown that the recurrence rate is between 20 and 80% in 5-20 years. Compression stockings, avoiding prolonged standing, watching your weight, and exercise all can help but eventually you'll see more veins.
Varicose. The average duration of this surgery is 30-45inutes. To prevent them, wear medically prescribed graduated compression stockings.