Single center experience with flow diverters Søren Jacob Bakke, Eva Jacobsen, Bård Nedregaard, Terje Nome, Bjørn Tennøe - Section of Neuroradiology, Oslo University Hospital - Rikshospitalet Oslo - Norway SNR October 8th 2010

Aneurysms treated 2008- 2010

Endovascular treatment 162 aneurysms i 25 months - 2008 - 2010. * 74 % (120) treated by coils alone ( 4 parent artery occlusions ) * 8 % (13) treated by balloon and coils * 13 % (21) treated by stent and coils * 5 %(8) treated by flow diverters

Stent used in aneurysms 2008-2010 21 of 162 aneurysms had 28 stents implanted (24 Enterprise and 4 Leo+) 8 were intended for flow diverters: 2 Pipeline (Ev3) No coils, length 2 cm required 2 telescoping stents in one aneurysm 6 SILK (Balt) 2 stent only,no coils. 3 had scaffolding Leo + first and then one or up to three telescoping SILK stents. 1 had dislocation of Leo+ and still no SILK implanted

Flow diverters - where to use Giant aneurysms (1) Fusiform dolicoectatic aneurysms (3) Complex wide neck aneurysms (4)

Results - follow-up 3-25 months PIPELINE (2) 2 without coils No complications, recovered SILK (6) 2 occluded aneurysms and fully recovered 1 did not open fully. Passed balloon occlusion test made us sacrifize the parent artery Recovered well 1 dislocated LEO+, still no SILK 1 with stent only, thrombosed partially the aneurysm, which increased in size and bled.Expired after by-pass surgery. 1dolicoectatic aneurysm made excellent recovery until day 3. Acute rupture and bleed - expired.

Results Morbidity: 4,2 % Ref.(3,7 % - 10%) * Mortality: 2,4 % Ref. (0 - 2.1%) * Flow diverters alone: Morbidity 4 / 8 Ref ( 15 % ) ** Mortality 2 / 8 Ref ( 4 % ) ** * I. Wanke. Intracranial aneurysms. (In Intracranial malformations and aneurysms Ed M Forsting. Springer 2003 ** Lubicz et al. Flow diverter stents for the endovascular treatment of intracranial aneurysms, Stroke 2010;41:2247

Case 1: 45 years old man Aortic valve surgery Ongoing Warfarin medication Headache brought him to MRI Huge fusiform MCA aneurysm SILK 3,5 x 40

10.09.2008 09.02.2008

DSA post stent (”Silk”) 10.09.2008 early later CT angiography 12.09.2008 Coronal view

So at 2, 3 and 5 months f/u... Increased aneurysm size, still flow Plavix only two months I asked for another SILK from Balt, but they told me to wait, observe .. Control at 5 months showed no flow on CTA, but increasing size. The increase in size could be from before it occluded? He was doing well - perhaps we should await shrinking ? But; At approx 5,5 months increasing headache and then rightsided hemiparesis.

25.02.09 18.12.2008 03.02.2009

CT/ CT angio 25.02.2009 MRI 25.02.2009 T2* T1 T2 (coronal)

Case 2 Man 63 years old Vertebrobasilar dolicoectatic aneurysm Increasing brain stem compression symptoms and hydrocephalus PCom – small Shunt Long LEO+ Then 3 telescopic SILK stents

2009 2007

Discussion cont.. May the systole press more blood out than goes back in diastole ?? Valve mechanism ? Or is biodynamic change of the thrombus also changing the aneurysms wall and biochemical forces induce rupture ? Autopsi of our second case showed a rupture at the proximal part of the aneurysm, still covered by stent and without sign of mechanical erosion inside.

Conclusion - Flow diverter stents SILK and PIPELINE offer a new option for some complex wideneck large or giant aneurysms, or even fusiform aneurysms with mass effect But in our hands flow diverter stents increase morbidity / mortality and a strong indication is mandatory. More than one stent may have to be used to give aneurysm occlusion and better delivery catheters and stent design will increase their use.

Discussion Heavy anticoagulated - should he rather had primary surgery ? Do we get and use tools to fast - better evaluation ? Inside the registry.. Should I have tried other stents inside - like LEO+ ?? Or more than one SILK? Why do the aneurysm grow ? Is SILK in some pts. semipermeable - produce leakage with no return like a valve mechanism ??

Flow diverters SILK and PIPELINE offer a new and good solution in some wideneck large or giant aneurysms, or fusiform aneurysms But it may need time to finally close the aneurysm and you may experience difficulties to open the stent properly when you deploy More than one stent may have to be used to give aneurysm occlusion