Any insult to a body part can cause problems. I would say removing a vein from a limb would certainly be considered an insult. Like any other wound it needs time to heal, it may take longer than expected due to a decrease in blood flow to the leg. Many times the blood flow is not noticably affected and things heal just fine. But there is always the exception, keep the MD informed. If there is an increase in redness, swelling, area is hot to the touch, a fever is present, or if level of pain is increased
( ecspecially in the calf when pointing toes toward your face ).Remember pain, swelling and redness are all normal it is when there is a change or increase in these things that COULD mean something MAY be going on. Only an MD can make this decision, but symptoms shouldn't be ignored either.
Did the Doc recommend the soak,always check with MD first even if it seems silly, I would guess that rest and elevation would be included between the excercise, check with the Doc or his nurse.