Surgical Approaches to Paraclinoid Aneurysms

OBJECTIVE: "Paraclinoid" aneurysms include those aneurysms arising from the internal carotid artery between the site of emergence of the carotid artery from the roof of the cavernous sinus and the origin of the posterior communicating artery. The authors reviewed and analysed the results of surgical approaches to paraclinoid aneurysms treated with transcranial surgery and endovascular surgery. METHODS: Between January 1998 and May 1999, 14 patients were treated surgically through ipsilateral and contralateral pterional approaches, and anterior interhemispheric approach, and endovascular surgery for paraclinoid aneurysms. All transcranial approaches were performed by same surgeon. The medical records, neuroimaging studies and videotapes which had been recorded operations were reviewed retrospectively. RESULTS: Twelve patients presented with subarachnoid hemorrhage and ICH. Nine of fourteen patients had multiple aneurysms. Thirteen cases were small and one was a large aneurysm. Six patients were treated through ipsilateral approaches, six contralateral pterional approaches, one anterior interhemispheric approach and one primarily by GDC embolization. All aneurysms treated through contralateral approaches were multiple aneurysms. Neck clipping was performed in 9(69.2%) of the thirteen aneurysms, wrapping in four cases, among them three cases were followed by GDC embolization. The surgical outcomes were: Glasgow Outcome Scale(GOS) I 71.4%, GOS II 21.4% and GOS V 7.1%. CONCLUSION: The surgical approaches to paraclinoid aneurysms should be chosen after careful anatomical evaluation of aneurysm and its neighboring structures. 3D-CT angiography and/or the raw data of MR angiography were useful. This study supports the usefulness of the contralateral approach to paraclinoid aneurysm associated with multiple aneurysms, unruptured and small aneurysms whose dome projecting medially, superiorly and dorsally. The determination of contralateral approach to small and medially projecting paraclinoid aneurysm may be stressful to operator, thus we believe anterior interhemispheric approach is better alternated. Also we recommend the endovascular surgery after reinforcement of aneurym neck and dome in the case with difficulty in clipping.

Surgical Treatment of Bilateral Intracranial Aneurysms

The incidence of the bilateral intracranial aneurysms in multiple aneurysms ranges from 20 to 40% in the published series12). The problems of surgery for multiple aneurysms are far greater than those for single aneurysm. Occasionally,the ruptured site of bilateral symmetrical(mirror image) aneurysms are more difficult to identify. To verify the standard treament, we investigated their clinical data and surgical modalities of 43 patients with bilateral aneurysms. We classified the bilateral aneurysms as symmetrical and asymmetrical aneurysms. Most common bilateral symmetrical aneurysms were located at origin of posterior communicating artery. Surgical modalities were separate craniotomy with ipsilateral approach(29 cases) and a single craniotomy with ipsilateral and contralateral approach (6 cases). The rest of patients were treated only in the presence of symatomatic lesions. Seven patients died of various causes; two were rebleeding, three were surgical mortalities, and two had medical complications. The surgical results were good to fair in 26 cases of separate operation and had good to fair outcome of 5 cases with 1 case of poor outcome in the single craniotomy with combined ipsilateral and contralateral approach. Surgical goal in patient with bilateral aneruysms is clipping of all aneurysms. In selected cases, the contralateral approach with a single craniotomy can be employed. Proper surgical techniques and guideline for microsurgical exposure of bilateral aneurysms are mandatory.