An 88-year-old patient underwent thoracic endovascular aortic repair for an incidentally discovered thoracic aortic aneurysm. Access was attempted via the femoral and external iliac artery approaches; however, insertion was not possible, and the procedure was completed via an open trans-aortic approach. Postoperatively, the patient developed acute lymphangitis and lymphedema in the inguinal region, resulting in extensive skin and subcutaneous tissue necrosis requiring debridement and skin grafting. Two incisions in the femoral and external iliac arteries were considered to be the cause of sudden lymphedema. This extremely rare case is reported in detail, with a discussion of the potential mechanism.