This is a case of an 81-year-old male who underwent stent-graft (SG) placement for type B aortic dissection at the age of 79. Two and a half years after the surgery, he was diagnosed with SG infection. Although he was scheduled for SG removal and the in-situ replacement of the descending aorta, he had difficulty maintaining oxygenation under single lung ventilation and detaching the severe adhesion of the aneurysm to the lung; therefore, only the aneurysm sac was opened, and abscess drainage was performed. The continuous irrigation and drainage of the aneurysm sac were performed, but the infection did not improve. On the 6th day after the surgery, the aortic aneurysm in the lung adhesion area was left untreated, and an extra-anatomical bypass was performed from the distal aortic arch to the anterior position of the pulmonary hilum, anastomosing with the abdominal aorta. All SGs were removed, the abscess and intima of the aortic aneurysm were extensively excised, and the remaining cavity was filled with omentum. The infection rapidly improved after the surgery, and he was discharged on the 52nd day after admission. Fortunately, the infection did not recur for 2 years since the surgery. This procedure is useful as an option for surgical reconstruction for stent graft infection for which in-situ descending aorta replacement is difficult.