A case of severe polyarteritis nodosa with critical limb threatening ischemia—promising treatment with sirolimus drug-coated angioplasty oleh Darius Kang Lie Aw, FRCS, Kalpana Vijaykumar, FRCS, Shin Chuen Cheng, FRCS, Tjun Yip Tang, FRCS, Jia Sheng Tay, FRCS, Edward Tieng Chek Choke, PhD, FRCS