Fig. 1

Dermal gangrene in three TAO patients who received long-term angiogenic treatment. a, b A 30-year-old man with a history of left below-knee amputation due to Buerger’s disease reported to us with severe Raynaud’s phenomenon in the right foot that had lasted for a month. He had undergone treatment with Prostavasin and, because of the dependency of the symptoms for Prostavasin perfusion, he underwent right lumbar sympathectomy, followed by treatment with bosentan. However, the pain diminished, and the foot warmed up for only 3 weeks after sympathectomy. By increasing the pain and discoloration of the foot, the patient received iloprost, followed by cilostazol for 7 months. Although the foot warmed and the dorsalis pedis pulse became palpable, the skin began to experience necrosis, whilst granulation tissue appeared under the dermal gangrene. Due to progression of the gangrene, the patient underwent a second BK amputation. The patient had stopped smoking during the treatment, according to self-report. c, d A 42-year-old man with an eight-year history of Buerger’s disease reported with a non-healing ulcer on his right ankle and burning pain in the right toes. He received antibiotics as well as cilostazol. The ulcer on the ankle completely healed over the course of 4 months. However, 2 months later, the patient developed a punched-out ulcer on the dorsum of the foot as well as some purpuric-like lesions, which became gangrenous and led to progressive dermal gangrene over the course of 6 months. Finally, the patient underwent below-knee amputation after 1 year of medical treatment. The patient had stopped smoking during the treatment, according to self-report. e, f: A 39-year-old man with a four-year history of Buerger’s disease underwent minor amputation and reported with a non-healing ulcer of the amputation stump. He was treated with cilostazol for approximately 2 years, and the ulcer improved. Recently, he developed localised, gangrenous papules and was advised to discontinue cilostazol. He has stopped smoking, according to self-report g, h A 49-year-old man with a 15-year history of Buerger’s disease began taking cilostazol for claudication. After 1 year, although the claudication had improved, localised dermal gangrene developed, and the cilostazol was discontinued. At present, the gangrene has resolved, but the claudication had progressed. The patient did not stop smoking during the treatment