下腸間膜動静脈瘻による虚血性腸炎に対しinterventional radiologyが奏効した1例

A case of ischemic colitis associated with inferior mesenteric arteriovenous fistula treated with interventional radiology

◆要旨：患者は74歳，男性．2年前に下行結腸癌（pT4a, N2, M0, Stage Ⅲb）に対する腹腔鏡下結腸部分切除（下行結腸）後，再発なく経過していた．下痢と腹痛を主訴に受診した．造影CTで動静脈瘻，虚血性腸炎と診断し，動静脈瘻による盗血症候群が原因と考えた．責任血管の閉塞目的にinterventional radiologyを施行し，動静脈瘻をヒストアクリル^®で塞栓した．動静脈瘻の成因に血管の一括結紮処理や手術操作による炎症が指摘されている．本症例は腹腔鏡下手術後であり，血管切離断端が近接していた．動静脈瘻の治療は外科的切除の報告が多くを占めるが近年は塞栓術も報告されている．腸管が温存可能で，比較的低侵襲であることから，interventional radiologyによる塞栓術は，術後の動静脈瘻の治療で有効な選択肢となる．

　Arteriovenous fistula is a rare but important complication possibly occurring after laparoscopic colectomy. The patient was a 74-year-old man who had undergone laparoscopic partial colectomy （Colon cancer, D, pT4aN2M0, Stage Ⅲb） 2 years previously with no recurrence. He presented with diarrhea and abdominal pain. Contrast-enhanced computed tomography showed evidence of an arteriovenous fistula and ischemic colitis. Interventional radiology was performed to occlude the causative blood vessel, and the arteriovenous fistula was embolized with Histoacryl. Inflammation due to blood vessel ligation or surgical operation has been reported as the cause of arteriovenous fistula. This case was after laparoscopic surgery and the end of the vascular transection performed during surgery was close to the site of the fistula. Inferior mesenteric arteriovenous fistula is very rare and there are reports that it can result in portal hypertension and ischemic colitis. The most commonly reported treatment is surgical resection, but in recent years embolization with interventional radiology has also been reported. Embolization with interventional radiology is effective for the treatment of post-operative arteriovenous fistula because the intestine can be preserved and it is relatively minimally invasive.