Internal Carotid Artery Trunk Aneurysms - Management and Outcome

Hong, Chang Ki; Ahn, Jung Yong; Joo, Jin Yang

Abstract

OBJECTIVE
Internal carotid artery (ICA) trunk aneurysms are rare constituting about 0.9 to 6.5% of all ICA aneurysms. They may arise from medial, lateral, ventral (posterior) or dorsal (anterior) walls of ICA. The most frequent site of origin is dorsomedial, followed by dorsal, dorsolateral and ventromedial wall. ICA dorsal wall aneurysms can be divided into the saccular type and blister type, which have different shapes, wall histological features and surgical tactics. The authors report an analysis of 27 cases of ICA trunk aneurysms treated with surgical clipping or GDC embolization.
METHODS
Of 145 cases of ICA aneurysms from May 1998 to December 2005, we found 27 cases (17.5%) of such unusual aneurysms located at nonbranching sites of the intradural ICA. Features of neuroimagings and medical records were analyzed.
RESULTS
Out of 27 aneurysms, 10 were located at ICA dorsal wall, 8 aneurysms were developed at ICA medialwall. Seven aneurysms originated from ICA ventral wall. Seven cases presented with subarachnoid hemorrhage and 20 cases were found unruptured. Two patients had blister-like aneurysm, and the others had saccular aneurysms. All patients were treated successfully with microsurgical clippings or GDC embolization. Microsurgical clipping were performed in 14 cases and among them, removal of anterior clinoid process was done in 12 cases. Eleven aneurysms were occluded with detachabel coil. Two patients underwent balloon occlusion of ICA. Blister aneurysm was clipped including a portion of the normal ICA wall. Good outcomes were obtained in 25 patients, and two patients were dead.
CONCLUSION
ICA trunk aneurysms are developed at any site of ICA circumference. Therefore we consider a variety of treatment strategies. On clipping of aneurysms at proximal ICA trunk, removal of anterior clinoid process is important. Endovascular treatment may be good an alternative. However, surgical treatment is essential for blister like aneurysms.