Masterclass #15: Flow diverters or stents-coils for distal aneurysms: enemy brothers?

Alejandro BERENSTEIN, Michel FRUDIT, Vitor MENDES PEREIRA, Jacques MORET, Laurent SPELLE

To treat distal aneurysms, which would you choose: stents and coils or flow diverters?

The way you answer this question might have something to do with your age, your comfort and experience in using one device over another, or it might be based on the technological evolution of the devices themselves – but do we have the data, the trials, or the evidence to choose one approach over another?

In this Masterclass, Professors Jacques Moret, Laurent Spelle and their expert panel discuss these questions while exploring special cases in the management of distal aneurysms that illustrate the two techniques and how they are used. Are both strategies feasible?

We know they both disconnect the aneurysm from the vascular system either by the stent maintaining coils within the aneurysm sac, or by the flow diverter re-directing the flow away from the aneurysm itself.

But are there specific problems posed by the distal location or the features inherent in each device that could impact our choice?

• Is it the sinuosity of the distal vessels or their smaller size?
• Does the amount of metal in each device matter? Is it true that the smaller the vessel and the greater the metal load of a specific device the more chance of occlusion?
• Are there more thrombo-embolic complications when flow diverters are used in small vessels than in large vessels?
• Do we know if a small vessel treated with a stent has less intra-device thrombosis than one treated with a flow diverter?

Will new sizes and coatings change the use of flow diverters in more distal locations?

Smaller, low-profile flow diverters are being introduced which can be deployed through 17 Fr microcatheters. Coated flow diverters are also available.

• Will this diminish thromboembolic complications, improve navigation or lessen the need for antiplatelet therapy?

If an occlusion occurs in a distal flow diverter – how would you treat it? A stentriever? Local fibrinolytic treatment?

Does antiplatelet therapy differ after deployment of either a flow diverter or stent and coils?

• Our current understanding of antiplatelet treatment comes from interventional cardiology – Are there any interventional neuroradiology trials studying antiplatelet treatment?

Are we about to change direction in the way we treat distal aneurysms?

Do we have the trials and studies we need to guide us, or the long-term anatomical results that would support either of these methods?

Are we, as Prof Moret says, “choosing between the good the better or the perfect?”

Let’s begin to find out.