Abstract
A 77-year-old woman who had been taking iguratimod and sarilumab for rheumatoid arthritis for 3 months had gas gangrene. After hospitalization, she underwent two debridement surgeries, one drainage procedure, and a free latissimus dorsi musculocutaneous flap transfer for the resulting tissue defect on the oral cavity through the temple. Following the free flap surgery, she experienced flap ischemia, possibly caused by the vasospasms of the intraflap and recipient arteries on postoperative days 5 and 6. These immunomodulating drugs might cause vasospasms by downregulating the interleukin-6 and/or tumor necrosis factor-α signaling pathway(s). Recent developments in antirheumatic drug therapy have increased the chances of performing microvascular surgeries on patients with inhibited immune systems, and this trend will continue or will be reinforced in the future. Close monitoring of the biochemical and clinical status of the microvascular environment is necessary.