Introduction: Flow diverters (FDs) for endovascular treatment of intracranial aneurysms carry the risk of occluding perforators and side branches. We aimed to determine the incidence and factors associated with supraclinoidal internal carotid artery (ICA) branch occlusion after placement of FDs for ICA aneurysms.
Methods: We reviewed patients who underwent endovascular treatment for ICA aneurysms using one or more FDs between June 2011 and March 2013. Patients in whom FDs traversed the origin of supraclinoidal ICA branches [ophthalmic (OA), posterior communicating (PcommA) and anterior choroidal artery (AChA)], and those who had a follow up cerebral angiogram (>= 6 months after embolization) available for review were selected for this study. Angiograms were studied to determine location of FD and patency of ICA branches. We identified the rate of angiographic branch occlusion, neurological deficits as well as factors associated with these events.
Results: Forty-nine patients (43 women, mean age 56.3±1.8 years) with 68 aneurysms were included. Mean follow up duration was 12.6±0.8 months. FDs were placed across the ostia of 50 OAs, 16 PcommAs and 11 AchAs. Multiple FDs were deployed in 16 patients. Distal ICA branches originated from the aneurysms dome or neck in 17 patients. The rate of ICA branch occlusion was 4% (2/50) for the OA, 18.7% (3/16 patients) for the PcommA and 0% for the AChA. Patients with angiographic ICA branch occlusion did not endure new neurological deficits. Angiographic occlusion was not associated with the number of FDs deployed or the origin of ICA branches from the aneurysm (p>0.05).
Conclusions: Angiographic occlusion was low for supraclinoidal ICA branches such as the OA and AChA (<5%), but relatively higher for the PcommA in patients treated with FDs. These events were not associated with new neurological deficits. The number of FDs placed did not increase the risk of branch occlusion.
Patient Care: By characterizing the rate and clinical correlates of side branch occlusion in the distal ICA, we provide important data for neurointerventionalists who intend to deploy FDs in the supraclinoid ICA for treatment of ICA aneurysms.Our data will help patients and doctors better estimate the risks of treatment of distal ICA aneurysms with FDs.
Learning Objectives: 1. Supraclinoidal ICA branches with robust collateral supply such as the posterior communicating arteries are susceptible to occlusion following endovascular treatment of aneurysms with flow diverters.
2. Arteries without substantial collateral supply such as the ophthalmic artery and anterior choroidal artery are more likely to remain patent even after flow diverters are placed across the arterial inlet.
3. Angiographic branch occlusion is not associated with the number of flow diverters deployed or the anatomical origin of the ICA branch from the aneurysm dome or neck.