If you don't take 500mg of Vit C daily already then start now and keep it going 3-4 weeks afterwards.

Gabapentin should help and is used pre-op to decrease chronic pain potential.

Ask if they are going to or can locally numb the puncture site with lidocaine or something. Ethyl chloride is nice (the freezy spray) if they don't do a local.

LitLove has mentioned preventing spread with lidocaine patches, so maybe you could use them on your leg afterwards.

They can give you something like versed to help you stay calm throughout. Depending on the setting and if you have a sympathetic and willing anesthesiologist they could give you a little ketamine in your IV. Find out all your options.

Let us know before you go so we can send healing vibes your way.