What Causes Swollen Feet,ankles And Calves Post Blockage Of A Vein In Legs?

My son, age 44 had very swollen feet, ankles & Calves. He had the procedure where a Vascular surgeon blocked off one vein in each leg with the hope that the remaining vein would start making the blood flow better. They never got better, and now 6 months later, both legs are about double in size and my son can hardly walk, let alone get a shoe on. What kind of doctor should he go to for help? He has done all the things that the surgeon asked like wearing compression stockings, etc. This has pretty much disabled him.