症例 二次性大動脈腸管瘻をきたし人工血管が腸管内へ迷入したと考えられた１例

症例は69歳男性．慢性下痢の精査目的で下部消化管内視鏡検査を施行した．横行結腸に２型進行癌を認めたが，その口側にY字型の人工血管を疑う異物を認めた．大腸壁に穿通を疑う部位は見られなかったが，上部消化管内視鏡検査で十二指腸水平脚に周囲からの襞集中を伴う多結節状隆起を認めた．腹部造影CT検査では，以前に置換された腹部人工血管は消失し，腎動脈分枝部より遠位側の腹部大動脈は血栓閉塞していた．また，十二指腸水平脚は背側で虚脱した腹部大動脈と癒着していたことから，同部位から人工血管が腸管に迷入したと考えられた．大動脈十二指腸瘻より人工血管が完全に腸管内へ迷入したきわめて珍しい症例であり，ここに報告する．

A 69-year-old man underwent total colonoscopy for chronic diarrhea. Past medical history revealed that a vascular graft had been inserted in the abdominal aorta 14 years previously. Colonoscopy revealed a vascular graft at the oral side of advanced carcinoma in the transverse colon. The site of penetration was not found in the colon, but esophagogastroduodenoscopy showed a scar at the third portion of the duodenum. Contrast-enhanced computed tomography revealed disappearance of the artificial aortic vascular graft and there were adhesions between the abdominal aorta and the third portion of the duodenum. These findings indicated that the vascular graft found in the transverse colon under colonoscopy had migrated through a secondary fistula that had formed between the abdominal aorta and the third portion of the duodenum. We herein report this intriguing case with a Japanese literature review.