gms | German Medical Science

Objective: Untreated giant and fusiform aneurysms within posterior circulation may have a disastrous clinical course. Treatment options for either primary microsurgical clipping or endovascular coiling are usually limited. We present our clinical experience of surgical flow diversion including flow extra-intracranial bypass surgery and vertebral artery occlusion as an alternative treatment in otherwise untreatable complex vertebrobasilar and posterior artery aneurysms.

Method: We prospectively followed up four consecutive patients with fusiform and giant aneurysms of posterior circulation which underwent surgical treatment resulting in aneurysm flow reduction/diversion at our department. Clinical symptoms, hospital course, operative intervention, and clinical and radiological outcome were evaluated. All patients were treated by the same surgeon.

Results: Four patients (1f/3m, mean age 47 y /range 21-59 y) were treated. Three patients had basilar artery aneurysms (one proximal fusiform aneurysm, two distal aneurysm fusiform and giant, respectively), one patient had a posterior artery giant aneurysm. Three of four patients presented with clinical signs due to brain stem compression such as gait ataxia, hemiparesis, nausea and vomiting, or diplopia. All patients underwent superficial temporal artery-posterior cerebral artery bypass surgery. In patients with basilar artery aneurysms, flow was reversed by bilateral endovascular occlusion of the vertebral arteries distal and proximal to the posterior inferior cerebellar artery, respectively. The mean preoperative modified Rankin Scale (mRS) score was 1.75 (range 1-3). Post-treatment angiography revealed sufficient flow diversion in all cases. There was no perioperative mortality. Two patients experienced new significant neurological deficit, one of them could partially recover during the follow-up. The mean postoperative mRS score was 2.5 (range 0-5). One patient demonstrated aneurysm enlargement 4 month after surgery.

Conclusions: Surgical flow diversion was achieved by extra-intracranial bypass surgery in combination with surgical or endovascular vessel occlusion. Regarding the aggressive natural history of these lesion, this treatment can be considered for patients with otherwise untreatable complex posterior and vertebrobasilar aneurysms despite significant perioperative morbidity.