虚血による大腸の管状狭小化の成因の考察―動脈塞栓術後の虚血性大腸炎の1例の検討から

Mechanism of Tubular Narrowing of the Colon Due to Ischemia: A Case of Ischemic Colitis after Transcatheter Arterial Embolization

要旨　虚血性腸炎のX線像でしばしば認める管状狭小の成因を知るために，憩室からの出血に対し動脈塞栓術を施行し，その後に生じた虚血性病変について，切除標本のmicroangiographyをもとに障害血管と病変との関係を検討した．切除標本では3本の直動脈起始部とその辺縁動脈は塞栓物質で閉塞し，その周囲の辺縁動脈には狭小化のみ認められた．辺縁動脈の閉塞している範囲ではUl-Ⅱ～Ul-Ⅳの潰瘍を生じ，狭小化のみの範囲には病変を認めなかった．X線像で管状狭小を来す病変は，病変（管状狭小）よりもやや広い範囲の辺縁動脈の血流障害に起因していると考えられる．

　Barium enema x-ray examination of the ischemic colitis often reveals tubular narrowing. To investigate the etiology of tubular strictured lesion of the colon due to ischemia, we analyzed a case of ischemic colitis which was followed by transcatheter arterial embolization for hemorrhage from diverticulum. We compared the macroscopic findings and microangiography of the resected specimen. Microangiography of the resected specimen showed 1) obstruction of the origin of three vasa recta and their peripheral marginal arteries with embolic substance, 2) stenosis of their surrounding marginal arteries. Ulcers (Ul-Ⅱ to UI-Ⅳ) were noted in the area of obstructed marginal arteries. No lesion was found in the area of vessels which had only stenosis. The extent of tubular narrowing may be slightly smaller than the area which obstructed marginal arteries should have perfused.