How do you improve circulation to a puppy's leg?

My puppy got her leg wrapped in a tarp and cut off circulation. We have taken her to the vet and he is leaning towards amputation. We are worried because she is a large German Shepherd and that would be hard on her hip because its the back leg. So we need to learn how to get circulation back to the leg. She is on anti-inflammatory starting today. We have tried soaking it in hot water with no results. We just wrapped it in a ace bandage wrap to try it. Please any advice can save this poor baby's leg.