The use of C1 inhibitor is effective for preventing attacks of angioedema in HAE patients during the perioperative period.
We report the case of a 27-year-old man with hereditary angioedema （HAE） who underwent oral surgery under general anesthesia. The patient was referred to us by a local doctor with a chief complaint of swelling of the gingiva around the left mandibular first molar. We diagnosed him as left mandibular radicular cyst involving the first molar based on the findings from CT and panoramic radiography. The patient underwent cystectomy with apicotomy of the affected root under general anesthesia at the patient’s request. To prevent edema, we injected C1 inhibitor before the surgery according to the HAE guideline. The patient received careful perioperative management and subsequent follow-up, and no complications have been observed.