TREATMENT OF GIANT MIDDLE CEREBRAL ARTERY ANEURYSMS WITH A FLOW REPLACEMENT BYPASS USING THE EXCIMER LASER-ASSISTED NONOCCLUSIVE ANASTOMOSIS TECHNIQUE

Abstract

To define the clinical value of the flow replacement bypass using the excimer laser-assisted nonocclusive anastomosis (ELANA) technique in the treatment of patients with a noncoilable, nonclippable giant intracranial aneurysm of the middle cerebral artery (MCA). Between 1999 and 2006, 22 patients with a giant intracranial aneurysm of the MCA were treated in our hospital with an ELANA flow replacement bypass and MCA occlusion. We collected data on patient characteristics, operative aspects, complications, and functional health scores using the modified Rankin Scale. Mean follow-up was 3.6 years (range, 0.2-7.7 yr). We were able to construct a patent bypass in 20 (91%) of 22 patients. All 34 ELANA attempts resulted in a patent anastomosis with a strong backflow directly after ELANA catheter retraction. The patients did not need to undergo temporary occlusion in any of the ELANA constructions. Mean +/- standard deviation intracranial-to-intracranial bypass flow was 53 +/- 13 ml/min. MCA aneurysm treatment was attempted in all 20 patients who had a patent bypass and was successful in 19 of them. There was a fatal hemorrhagic complication in one patient (5%), a nonfatal hemorrhagic complication in three patients (14%), and a nonfatal ischemic complication in six patients (27%). At follow-up, 17 patients (77%) had a functionally favorable outcome (modified Rankin Scale score at follow-up was the same as or less than the preoperative modified Rankin Scale score). All of these patients were independent at follow-up (modified Rankin Scale score < or =2). This study demonstrates satisfactory results in the treatment of giant MCA aneurysms with an ELANA flow replacement bypass, considering the very grave natural history and treatment complexity of these lesions. The ELANA technique is a useful tool in the treatment armamentarium of the vascular neurosurgeon.