Arterial-bronchial fistula from ruptured immunoglobulin G4-related subclavian artery aneurysm.

Immunoglobulin G4 (IgG4)-related disease is a systemic chronic inflammatory disease caused by infiltration of IgG4-positive plasma cells into the systemic organs. IgG4-related arterial disease is relatively rare not only in the aorta but also in the small to medium-sized arteries. If IgG4-related vasculitis is suspected on the basis of the preoperative medical history and radiologic and serologic examination findings, a definitive diagnosis can be obtained by open repair and pathologic examination to determine the prognosis and need for additional treatment. Here, we report the successful treatment of arterial-bronchial fistula caused by a ruptured IgG4-related subclavian artery aneurysm.