10mm size MCA aneurysm - SLICE Next Frontiers 2022 - Annie JOB

Pedagogic case on stage! Prof Vincent Costalat, Dr Adnan Siddiqui and live from CHU de Montpellier Prof Michel Piotin and Prof Paolo Machi

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

Unruptured scenario: 

Pre-procedural planning: 

• In aneurysms bigger than 12mm, the WEB device is not an option and you typically propose stent-coiling for these aneurysms. If both branches are involved in the disease then it is a typical case for Y-stenting.
• Clipping is always an option in these aneurysms, however larger size means that clipping is also more difficult and the reconstruction of the neck may not be that simple;
• If you contemplate clipping, intrasaccular thrombus or calcification may be assessed as they pose significant problems with clipping. Also clipping MCA aneurysms with short M1 segments may prove dangerous as you would have to put a temporary clip on a region where there are lots of lenticulostriate arteries. 
• Probably endovascular approach is safe enough and provides reasonable long-term results;

Y-stenting technique:

• It is reasonable to contemplate Y-stenting with open-cell design stents or at least to use an open-cell design as a first stent.        
  1. They have less metal so theoretically would lead to less thrombogenicity;
  2. They have a much better anchoring in the vessel so you may ensure that you do not displace your first stent when you try to pass it with a microcatheter;
  3. After recrossing you may choose a braided-stent as a second stent if you think that there is a very high chance of recanalization, but using two open cell design stents is totally feasible.
  4. Open cell struts of the Neuroform Atlas stent may facilitate catheterization of the second branch by offering support.
• Which branch to catheterize first? 
  1. Theoretically you should catheterize the hardest branch first, but this is not always evident as you can always have surprises. 
  2. It is recommended to do wire-palpations and try to see how difficult it is to catheterize each branch before deciding where you will put your first stent.
  3. After putting in your first stent, the anatomy totally changes as well as the conditions of catheterization, so expect of having surprises while trying to catheterize the other branch. Use the smallest and most low-profile catheter for catheterization (Headway Duo) and ensure that your first stent has a long anchoring proximally and distally as the biggest risk is to move it during catheterization inside the sac. 

• Techniques if you cannot catheterize the branches?
  1. Do a turn inside the aneurysmal sac, in unruptured cases, using a low-profile 0.17 microcatheter (ex. Headway Duo); 
  2. In some catheters newer more steerable guidewires like the Aristotle and Columbus wire are an option for difficult catheterizations;
  3. Opening a small-sized WEB at the level of the aneurysmal neck and using WEB redirection is also a feasible way of catheterizing difficult vessels;
• While doing a turn inside the aneurysmal sac – you should always have a balloon ready nearby in case you perforate the sac;
•  Can we perform Y-stenting with a low-profile 0.17 microcatheter  (Headway Duo)? 
  1. Yes it is totally possible and provides the highest chances that you don’t move your first stent on catheterization of the second branch;
  2. You should expect to have no problems in pushing the stent inside a Headway Duo, however, if you use braided stent you may expect it is harder to pull it inside or to play with the stent;
  3. Theoretically open-cell stents are not recaptured so there is no need to use more rigid microcatheters;

• It is advised to always use two different microcatheter brands so as to clearly differentiate which is in the aneurysms/ which is in the branch/ which is in which branch;
• Jailing is a great idea for small aneurysms but in bigger aneurysms, repassing may be better and offer an advantage for adequately coiling the sac;
• If you did a turn in the sac, don’t attempt to remove the slack of the microcatheter before putting it in your stent. Deploy your stent a few mm and use this distal anchor to pull on your microcatheter and remove the slack from the system before further unsheathing your stent.
• Theoretically you should use the longest stent available for your first stent in order to ensure good long landing zones and a low chance of moving your stent while you attempt to catheterize the second branch;

Ruptured scenario:                                                                                            

Pre-procedural planning: 

• May not always be a surgical case;
• If the GCS is not affected and the hematoma is just in the sylvian fissure you may get away without operating on it in the initial phase;
• Decompressive craniectomy may be an option to deal with subsequent mass-effect if there is no obvious need of removing the hematoma;
• So if you have to treat it endovascular there are two widely used options:
  1. Balloon-remodeling;
  2. 2-microcatheter technique;

Two microcatheter technique:

• Ideally used for the treatment of ruptured wide-neck bifurcation aneurysms where catheterization of the branches is difficult to impossible without doing a turn in the sac, which is not to be advised with a balloon or in a ruptured aneurysm; It can also be used to treat aneurysms in which proper ballon-remodeling techniques fail to work due to the local neck anatomy;
• Using two microcatheters inside a sac at the same time will make it easier to perform a proper cage and stabilize the coils;
  1. The microcatheters should be of different forms (like a straight and a 90’’ or a 45’’’);
  2. They should be placed at different portions in the sac, one at the neck and the other deep inside the sac;
  3. You may choose smaller coils as you would ordinarily choose, so for example for a 12mm you might choose a 10 and 9 mm coil;
  4. Push coils from both catheters and try to play with the microcatheters to create a good cage, the advantage is that you can put in two long coils before detaching; 
• Don’t look for perfect results in these situations and with this technique, remember that you only have to protect your patient and that you can always come back and have a perfect result with a Y-stenting after the acute phase;
• The total time should not last more than 30 min in a Fischer 4 aneurysm;

Sources :
https://pubmed.ncbi.nlm.nih.gov/25431306/
https://pubmed.ncbi.nlm.nih.gov/26093360/
https://pubmed.ncbi.nlm.nih.gov/29438551/
https://pubmed.ncbi.nlm.nih.gov/31972346/