心膜腔へ直接破裂した嚢状弓部大動脈瘤の1剖検例

An autopsy case of saccular aneurysm of the aortic arch with direct rupture into the pericardium

　胸部大動脈瘤の心膜腔への破裂は，上行大動脈瘤では生じやすいが，他の部位の大動脈瘤では少なく，特に生前に診断されることはきわめて稀である^1〜5）。今回著者らは，心膜腔へ直接破裂した嚢状弓部大動脈瘤の症例を経験したので剖検所見とともに報告し，若干の文献的考察を行った。

An 80-year-old woman had a sudden onset of oppression in the chest and back and lapsed into shock. An X-ray film of the chest and a CT scan of the thorax showed a saccular aneurysm of the aortic arch and a moderate amount of pericardial effusion. An autopsy revealed the aneurysm ruptured directly into the pericardium.

So far as we refer, no cases of an aneurysm cf the aortic arch with direct rupture into pericardium have been diagnosed in life. And more, there have been no reports examined from a pathchistcicgical point of view.

We confirmed by autopsy the wall of the aneurysm adhered tightly to the epicardium, and that in this region the cavity of the aneurysm connected with the pericardium. The aneurysm was 4.5 cm in di-ameter, which seemed to be too small to rupture. According to many reports a greater part of ruptur-ing aneurysms were more than 10 cm in diameter.

Adhesion of aneurysmal wall can make a rupture into unexpected regions. We consider the wall in the adhering region is so thin and poorly extensible that the rupture of the wall occurs more easily than in the case of an aneurysm of a size without adhesion.