Pre-planning:

• Psychological factors in unruptured aneurysms play a role in the decision to treat, but they should mostly be relied on when the size of the aneurysm is less than < 7 mm; 
• You should always use UIATS score when doing consultations or balancing decisions to treat or not to treat unruptured aneurysms;
• Always analyze the anatomy to decide the proper treatment. You should analyze if the aneurysmal sac incorporates the branches, if the disease involves the branches reconstructing them with stents may favor stability; However, the more stents you use for an MCA aneurysm the higher the expected complication rate and the more unfavourable it compares to microsurgery; 
• When choosing between an intrasaccular device strategy or a Y-stent strategy for an unruptured MCA bifurcation aneurysms you have to consider that Y-stent permanent complication of 3-5% (based on retrospective mostly single-center series, likely underestimated) is compared to <1% permanent complication of WEB (peer-reviewed data, independently attributed);

Tips&Tricks for WEB deployment:

• Use simulation in order to choose the right device and to visualize if you have any danger of protrusion towards one of the branches; 
• If you see or believe that the device tends to protrude towards an M2 branch it is a good strategy to use a dual-lumen balloon in this branch, you may deploy the WEB with the balloon inflated to reposition it or you may just use the balloon to protect the branch and put in a stent after you perform vasoCT if you think it is necessary; 
• It is impossible to “balloon WEBs” because WEB is a nitinol device and it will return to its normal shape, however deploying it with an inflated balloon in the dangerous branch, may help twist the WEB so that it positions well. An alternative strategy is to make a different form on the delivery microcatheter to arrive at different angles in the sac;
• It is always good to palpate the two branches of the bifurcation with the guide-wire at the start of the procedure to know if they are easily accessible to plan bail-out strategies in case of complications;
• If you have doubts you should always perform VasoCT before deployment so as to appreciate the protrusion in side branches;
• The VIA is a stiff catheter you want to be as close as possible to the center of the aneurysm;
• You may stent just after you deploy the WEB. The literature data suggest that 60% of the cases are usually pre-planned and 40% are bail-outs. 
• Neuroform Atlas may not always open a branch in which a WEB protruded so you may try at the start with a braided stent which you can also resheath. A bail-out strategy if possible is to open your stent with a coronary stent;

Strategies for single-stent coiling in wide neck-bifurcation aneurysms:

• Keep in mind that Y-stenting makes the treatment feasible, this doesn’t mean that it makes it safe.
• Y-stenting offers excellent stability but is associated with more complications; 
• Several faculty members prefer surgery (if possible) for bifurcation aneurysms as they believe it is less aggressive than Y-stenting;
• The idea is to protect your aneurysmal neck during coiling and you have options of balloons, kissing balloons, or Comaneci devices; For this strategy, you may not want to use an intermediary catheter because you will need 3 microcatheters: one jailed, one balloon and one Comaneci device (inside a 7 Fr access); 
• You can coil your aneurysm using a balloon and/or Comaneci protection and you will be able to stent one branch at the end (in order to ensure stability for the treatment). With this strategy you will be able to stent the branch that makes more sense (or in which you have a small protrusion);
• While doing this kind of complex procedure with balloons the risk of thrombosis occurs mainly during the procedure so ensure:
  1. Good heparinisation;
  2. That balloons are not kept up more than a few minutes (maximum five);
  3. That balloons once deflated you give enough time for the downstream territory to reperfuse;
  4. That you keep an eye on the GA, because procedures with balloon inflation probably fare better with higher median blood pressures, in order to help the collateral circulation;
     
• When you coil with balloons and/or Comaneci devices you should coil more cautiously than when you are protected by a stent. You still want to construct a good cage with good neck protection;

Strategies for Contour deployment:

• It is used with 0.021 or 0.027 microcatheters depending on the size of the neck; 
• Sizing is important, simulation is not yet available so you have to rely on the sizing charts offered by the company;
• Probably ideally used in shallow aneurysms, because it reduces the interaction with the dome;
• Theoretically you would use a contour similar to the way you use a WEB and play with your microcatheter and the device in order to find the good position that covers the neck;  
  
  

DEVICES IN USE

BLOC A

WEB™ MICROVENTION

LVIS™ EVO MICROVENTION

Scepter XC® MICROVENTION

BLOC B

Avenir Coil System PHENOX

Comaneci 17 RAPID MEDICAL

Scepter XC® MICROVENTION

Contour Neurovascular System™ CERUS