I’ve heard that there’s a surgical procedure to improve raynaud’s. What is it?

Sympathectomy. Thoracic sympathectomy is the procedure to cut the "sympathetic nerve" fibers coming out of the spine at the level of t2-t3 (second and third thoracic vertebrae). The nerve fibers usually cross over the second, third, & fourth ribs near the spine. Some doctors are using an endoscope to do this procedure, which would leave almost no surgical scar. The same procedure stops excessive hand sweating.
Sympathectomy. Either surgerical sympathectomy or with a spinal stimulator can sometimes be used to cause vasodilation of the arteries.