中大脳動脈塞栓症に対するtransluminal angioplasty:硬い塞栓の血行再開に有用であった1例

A case of acute occlusion of left middle cerebral artery due to an embolus treated successfully with percutaneous transluminal angioplasty

I．はじめに

　最近，超選択的に頭蓋内血管まで挿入できる2-3 Frのmicrocatheterの普及やtissue plasminogen activator（以下t-PAと略す）の使用が可能となり，脳塞栓症に対するlocal fibrinolysisが盛んに行われるようになり，比較的良好な結果が得られるようになってきた^12,14）．しかし，再開通率は約60％前後とされており，再開通を得られなかった例では，依然として予後不良である．

　今回われわれは，重症虚血が推定された左中大脳動脈塞栓症の例に対して，t-PAを動注し再開通が得られなかったため，引き続き，micro-angioplastic balloonによるpercutaneous transluminal angioplasty（以下PTAと略す）を行った．塞栓は硬く，その圧砕に高いballoonの拡張圧を要したが，迅速に再開通を得て，症状の著しい改善を認めた．術後，末梢小血管への塞栓は合併したが，重篤な出血性梗塞は回避することができた．注意点などを文献的考察を含め報告する．

The acute occlusion of cerebral artery by embolism causes severe cerebral infarction. In cases with poor co-lateral circulation, cerebral infarction develops more severely. In these cases, quick recanalization of the occluded cerebral artery is necessary to prevent severe hemorrhagic infarction and brain edema. We report a case where interventional techniques were used to bring about quick recanalization of occluded cerebral artery.

We encountered a case of a sixty-year-old male who experienced complete occlusion of the left middle cere-bral artery due to an embolus. It was very hard to pass a guide wire through the embolic lesion. At first, we tried mild local fibrinolysis therapy using tissue plasmi-nogen activator, but we could not get any recanaliza-tion. However, after mild local fibrinolysis therapy, the guide wire could be passed through the occlusion point. Secondly, we tried percutaneous transluminal angio-plasty (PTA) with 2.0mm diameter angioplastic bal-loon using up to five atomic pressures, after which we obtained partial recanalization. Finally we achieved tot-al recanalization of the middle cerebral artery by PTA with a 2.5mm diameter angioplastic balloon. We crushed this embolus using the angioplastic balloon with up to six atomic pressures. The point of the tech-niques is to press the embolus against the arterial wall. After this angioplasty, there was an occlusion of the common trunk of the posterior parietal artery and the angular artery. However there was neither massive hemorrhagic infarction nor massive brain edema on fol-low up CT.

In the treatment of acute occlusion of the cerebral artery due to embolism, we found PTA is very effec-tive against the embolus. In the future, we need to de-velop a retrieving device and a balloon that will pre-vent the production of small emboli during the crush process involved when bringing about recanalization using PTA.