Endovascular treatment of MCA - SLICE Next Frontiers 2022 - Julien CIAGAR

Endovascular treatment of MCA “surgical” aneurysms:

Treatment of a wide-neck >10mm size MCA aneurysm in a ruptured or unruptured scenario

Tips & tricks for wide neck unruptured trifurcation aneurysms: 

Pre-procedural planning: 

• Consider surgery if branches seem to be difficult to protect with endovascular treatment;
• In small fusiform aneurysms without large neck-to-dome diameters, observation and follow-up is also an option if you think that the risk of treatment is high;
• In patients in which you think that the rupture risk is very low, the risk you take with your treatment strategy should also be very low;
• The most simple technique is not always the best technique;
• Intrasaccular devices are low-risk treatment options; simulation should be used in order to appreciate the fitness of any WEB inside shallow aneurysms. It is important to verify if the intrasaccular devices protrude inside each of the three branches before even starting the procedure; This may reduce dangerous maneuvers or even inadvertent deployment with secondary complications; 
• Stent-coil planning in shallow trifurcation aneurysms is especially important in order to aid the visualization of how a stent may protect other branches. It may permit you to use one single stent, which may transform a complex situation into a simple one, reducing the complication rate and the technical dimension of the procedure.
• Simulation may help you oversize laser-cut stents and use the open-cell design in order to protect branches that you otherwise thought were not protectable; 
• Oversizing laser-cut stents in small branches is totally feasible, as the metal coverage is low <10%; 
• Neuroform atlas stents can be used, based on simulation, to perform similar to “Barrel” stents which actually protect branches by opening up before the aneurysmal neck;
• When you put a stent with a bulging effect you always have to resize your coil because the stent will reduce the volume of your aneurysm. Simulation may also help with proper coil selection in these conditions; 

An unruptured scenario in MCA trifurcation aneurysm with early temporal branch:

Pre-procedural planning:

• Use simulation in order to verify if intrasaccular devices in early branch aneurysms, may work and may provide a safe option;
• Catheterising recurrent early branches is often very difficult and technically demanding;
• Flow diversion in trifurcation aneurysms poses several problems even if theoretically it looks like a simple, straightforward treatment.
  1. In MCA bifurcation, overall literature reported data shows that flow-diversion treatment complication rate is 20% with 10% permanent morbidity, most of these complications do not arise during the procedure.
  2. While expected complications rate for laser-cut stent-coiling in MCA bifurcation aneurysms is 10% with 3% permanent morbidity. 
  3. Surgery, for these aneurysms may have morbidity rates of less than 5%. 
• Do not expect to get away, without a good anchoring of flow-diverters in these regions;
  1. Small anchoring of <5mm may lead to complications and may make safe flow-diverter deployment tricky even in experienced hands; 
  2. Moreover, small distal anchoring <5mm may lead to recalibration due to the proximity of the aneurysmal sac and promote fishmouthing; 
  3. Stents in unstable conditions with small anchoring zones may be displaced even after initial apparent good results. This may happen because the intrinsic nitinol properties of the stent facilitate the stent returning to the most stable resting position, which may be changed based on different artery pulsatility.

• If you use scaffolding stents for flow-diversion with small distal landing zones it is suggested to use braided stents; This may be an option to anchor your flow-diverter in difficult distal anchoring; 
• If you use telescopic stenting, the second stent will be affected by less place and will elongate even if you already take a smaller size;
• You can always navigate in stents with a low-profile 0.17’’ microcatheter like Headway Duo, which together with a small J-shaped microguidewire is a very safe way to recross inside stents and makes it safe to deploy small compatible flow-diverters or braided stents;
• You can always think about staged procedures which are totally acceptable in unruptured aneurysms; Posing a first braided- stent in order to offer a good scaffold and after that return after the endothelisation phase in order to put in a flow-diverter. This reduces risk by reducing the risk of moving the first stent immediately after it was placed.