Wan *, male, 31 years old, was admitted to the hospital with the main complaint of "redness, swelling, and pain in the right lower limb for 8 years, accompanied by gangrene for 3 months." Three months ago, the tip of his right toe became ulcerated. He underwent a right femoral artery and great saphenous vein artificial fistula formation at an affiliated hospital of Nanchang University. After the surgery, the gangrene on his right foot worsened and extended to the dorsum of the foot. He was discharged on the same day as the surgery. Subsequent treatments locally proved ineffective, with continuous aggravation of pain and ulcers. The pain became unbearable. The local hospital suggested amputation. In search of conservative treatment, he came to our hospital in February 2009. After admission, combined with various examinations, he was diagnosed with thromboangiitis obliterans. Specialized examination showed: hair loss on both lower limbs, the right lower limb was significantly thinner than the opposite side, the muscles were soft and lacked elasticity. There was dry gangrene on all five toes that extended to the dorsum and sole of the foot, with clear demarcation lines. The area was sensitive to touch, with dark red swelling around the gangrene, increased skin temperature, and palpable dorsalis pedis pulse...