抄録
Recently combined ligation of ICA and STA-MCA anastomosis has become the treatment of choice for unclippable giant aneurysms of the ICA. However, ischemic complications have been reported in 10-25% of the cases that underwent this procedure, because of the limited flow provided by the STA-MCA bypass and of thrombo-embolic ischemia originating from the stump of the occluded ICA and thrombosing aneurysm.
An interposed long saphenous vein bypass graft was utilized between the axillary artery and the angular branch of the middle cerebral artery instead of STA-MCA anastomosis to treat a patient with an unclippable giant aneurysm of the cavernous portion of the right ICA combined with acute ligation of CCA. Ten minute manual compression of the right CCA developed neither abnormality of EEG nor ischemic symptoms. Angiography also demonstrated a good cross-filling of the ipsilateral carotid region. However, a SPECT subtraction study revealed 70% reduction of flow in the ipsilateral MCA region by manual compression of the right carotid artery. Intraoperative measurement of the flow through the vein graft was 80ml/min. CCA ligated acutely on the third postoperative day after the patency of the vein graft bypass was assured. A postoperative angiogram revealed that the giant aneurysm was thrombosed successfully. There was a good filling of the left MCA territory through the graft and ACA through the anterior communicating artery from the contralateral circulation. Thus the ICA giant aneurysm was isolated, trapped and thrombosed. The postoperative SPECT study revealed a normal CBF at rest in both hemispheres. By compressing the vein graft bypass, 60% reduction of CBF in the MCA territory was demonstrated in the subtraction image of the SPECT. A three year follow-up revealed good patency of the vein graft with no ischemic symptoms.
Acute ligation of CCA provides less chance of emboly, and a vein graft bypass from the axillary artery can provide an immediate postoperative high flow without carrying thrombi from the ICA stump. The giant aneurysm of the intracranial ICA is isolated from ipsilateral cerebral circulation. Thus, both hemodynamic and thrombo-embolic ischemia can be avoided.
