Maximilian Patzig, Presenter: Nothing to Disclose

Lorenz Michael Ertl MD, Abstract Co-Author: Nothing to Disclose

Robert Forbrig, Abstract Co-Author: Nothing to Disclose

Hartmuth Brueckmann, Abstract Co-Author: Nothing to Disclose

Gunther Fesl MD, Abstract Co-Author: Nothing to Disclose

Long–term data on aneurysm treatment with flow–diverting stents are still sparse and follow-up protocols differ widely between institutions. We present long–term results, with a focus on the usefulness of 3T-MRI including contrast–enhanced MR–angiography (ceMRA).  

Patients with aneurysms treated by flow – diverting stents without additional coiling and follow–up MRI after at least six months were included. 3T-MRI protocol included dedicated ceMRA in arterial and venous phase. Aneurysm thrombosis, size of the aneurysmal sac and complications were evaluated. Additionally, we graded the ability of MRI with ceMRA to visualize these parameters on a 1 – 3 scale.

Twenty-one patients were included. Aneurysms were incidental in 15 cases and symptomatic in six cases (all cranial nerve palsies, no acute subarachnoid haemorrhage). Stenting was performed with ‘Pipeline’ in 17 cases and ‘Silk’ stents in four cases. Four technical complications occurred, one of which caused clinically apparent ischaemia. Duration of follow–up was more than two years in 16 patients. Complete occlusion of the aneurysm occurred in 18 cases (86 %). Of 13 cases in which a three-month-follow-up was available, seven were occluded at that time (54 %). At six months, 18 aneurysms were occluded (86 %). The aneurysmal sac shrinked in 16 of the 18 occluded aneurysms, in 11 cases to less than 50 % of the original size. On follow–up, one small perianeurysmal haemorrhage and one in–stent stenosis were found on MRI. Three of the symptomatic patients improved clinically. CeMRA assessability of aneurysmal thrombosis and size of the aneurysmal sack was graded as good in all cases. Where available, no discrepancies were found between ceMRA and digital subtraction angiography regarding aneurysm perfusion. Assessability of the stent lumen was reduced in cases treated with ‘Pipeline’ and good in cases treated with ‘Silk’.

Flow - diverter treatment can achieve high occlusion rates and cause major aneurysm shrinkage in many cases. MRI with ceMRA proved highly valuable regarding imaging of the aneurysm and late complications. The assessability of the stent lumen on ceMRA depends on the stent type.

Our study adds to the understanding of the development of aneurysm thrombosis and shrinkage after flow – diverter treatment and presents 3T-MRI with ceMRA as a highly valuable follow-up imaging tool.

Patzig, M, Ertl, L, Forbrig, R, Brueckmann, H, Fesl, G, Intracranial Aneurysms Treated by Flow – Diverting Stents: Results of Long-term Follow-up with Contrast-enhanced MR-angiography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010629.html