Suggest Treatment For Cramping Pain And Burning Sensation In The Legs

Yes thank you, my well nourished 75yr old husband had a AAA repair done 3/13/15. After a very successful surgery with stent he experienced leg problems the same day. Only while standing never sitting, he experiences leg pain cramping,burning starting at the groin, going down both legs. It s a difficult feeling to describe. He has had MRI only to find moderate stenosis L4 L5. He had an injection in that area to see if that helps or not. It s been 4 weeks w/o relief. It s not something the Dr s have see before as this is intermittent pain. My husband has to sit down to relieve the attack. He is on oxygen following LR Lung resection, he is otherwise healthy at this point. HR and BP normal Any ideas?