Result of extracranial-intracranial bypass surgery in the treatment of complex intracranial aneurysms : outcomes in 15 cases

Abstract

Objective: The standard treatment strategy of intracranial aneurysms includes either endovascular coiling or microsurgical clipping. In certain situations such as in giant or dissecting aneurysms, bypass surgery followed by proximal occlusion or trapping of parent artery is required.

Methods: The authors assessed the result of extracranial-intracranial (EC-IC) bypass surgery in the treatment of complex intracranial aneurysms in one institute between 2003 and 2007 retrospectively to propose its role as treatment modality. The outcomes of 15 patients with complex aneurysms treated during the last 5 years were reviewed. Six male and 9 female patients, aged 14 to 76 years, presented with symptoms related to hemorrhage in 6 cases, transient ischemic attack (TIA) in 2 unruptured cases, and permanent infarction in one, and compressive symptoms in 3 cases. Aneurysms were mainly in the internal carotid artery (ICA) in 11 cases, middle cerebral artery (MCA) in 2, posterior cerebral artery (PCA) in one and posterior inferior cerebellar artery (PICA) in one case.

Results: The types of aneurysms were 8 cases of large to giant size aneurysms, 5 cases of ICA blood blister-like aneurysms, one dissecting aneurysm, and one pseudoaneurysm related to trauma. High-flow bypass surgery was done in 6 cases with radial artery graft (RAG) in five and saphenous vein graft (SVG) in one. Low-flow bypass was done in nine cases using superficial temporal artery (STA) in eight and occipital artery (OA) in one case. Parent artery occlusion was performed with clipping in 9 patients, with coiling in 4, and with balloon plus coil in 1. Direct aneurysm clip was done in one case. The follow up period ranged from 2 to 48 months (mean 15.0 months). There was no mortality case. The long-term clinical outcome measured by Glasgow outcome scale (GOS) showed good or excellent outcome in 13/15. The overall surgery related morbidity was 20% (3/15) including 2 emergency bypass surgeries due to unexpected parent artery occlusion during direct clipping procedure. The short-term postoperative bypass graft patency rates were 100% but the long-term bypass patency rates were 86.7% (13/15). Nonetheless, there was no bypass surgery related morbidity due to occlusion of the graft.

Conclusion: Revascularization technique is a pivotal armament in managing complex aneurysms and scrupulous prior planning is essential to successful outcomes.

Keywords: Cerebral aneurysm; Extracranial-intracranial bypass; Outcomes.

Fig. 1

Superficial temporal artery-middle cerebral artery bypass is done on M4 segment of temporal operculum for low-flow bypass.

Fig. 2

A case of 61-year-old female presented with headache and visual disturbance due to giant intracavernous aneurysm. A : Anteroposterior right carotid angiography shows intracavernous aneurysm involving the whole cavernous internal carotid artery segment measuring 2× 4 cm (black arrow). B : Postoperative angiogram shows patent radial artery graft anastomosis on M2 (white arrow) with complete occlusion of aneurysm and parent artery by balloon. C and D : Postoperative computed tomography scan shows resolution of preoperative mass effect of aneurysm.

Fig. 3

A 56-year-old female presented with altered consciousness. A : Precontrast computed tomography scan revealed Fisher grade IV subarachnoid hemorrhage. B : On postictal day 1, preoperative anteroposterior left internal carotid artery (ICA) angiography showed blood blister-like aneurysm (black arrow). C : On postictal day 4, angiography reveals enlarged size of aneurysm (white arrow). D : Emergent radial artery bypass (M2) with ICA trapping was done to salvage unexpected occlusion of ICA during direct clipping of aneurysm (arrow head). E : Decompressive craniectomy was done to relieve brain swelling due to postoperative infarction and resulted in occlusion of graft.