Full Intrasaccular: Sidewall and Complex Aneurysm

This live demonstration highlights several important technical aspects of intrasaccular aneurysm treatment, particularly microcatheter stability, WEB sizing, deployment strategy, and the specific challenges of sidewall aneurysms. A central message is that catheter stability is critical for controlled deployment. Appropriate catheter shaping and angulation can improve support and modify the effective trajectory into the aneurysm, allowing more stable positioning. With increasing experience, re-entry into the aneurysm may occasionally be achieved without reintroducing a guidewire; however, the faculty specifically recommends guidewire-assisted navigation during the learning phase rather than considering wire-free access a routine technique.

Deployment should be understood as a dynamic interaction between the implant, microcatheter, aneurysm geometry, and parent vessel. The catheter trajectory should reflect both the axis of the parent artery and the aneurysm itself. Excessive angulation may significantly deform the proximal portion of the WEB and make its final configuration difficult to predict while the device remains constrained. This is particularly relevant in sidewall aneurysms, where substantial catheter angulation can temporarily distort the implant. Importantly, such deformation does not necessarily represent the final device configuration: after release of catheter constraint and detachment, the WEB may recover toward its intended geometry. The operator therefore needs to understand device mechanics and correlate the apparent intraprocedural shape with preprocedural simulation and the expected final configuration.

The fundamental objective remains effective neck bridging rather than simple aneurysm filling. The proximal surface of the implant and its relationship to the neck should therefore be assessed carefully before detachment. Excessively intradomal positioning or inadequate neck coverage may result in an unfavorable angiographic result and potentially contribute to recurrence. This is closely related to accurate sizing, which the faculty repeatedly emphasizes as one of the most important determinants of treatment durability. Device selection should incorporate aneurysm width, height, neck configuration, anticipated deformation, and the desired neck-bridging effect rather than relying only on nominal device dimensions.

Sidewall aneurysms are presented as feasible but technically more demanding targets. Important difficulties include marked catheter–aneurysm angulation, deformation of the proximal implant, difficulty predicting the final shape while the device is constrained, and potential protrusion into the parent artery. Careful sizing, catheter positioning, experience, and appropriate case selection are therefore particularly important. Irregular morphology should generally be approached cautiously, especially early in the learning curve, while partially thrombosed aneurysms, very large necks, dissecting configurations, and excessive angulation are also identified as challenging or unfavorable situations.

Another important lesson is not to rush detachment. Angiographic assessment, including native/unsubtracted imaging when appropriate, should confirm device configuration, neck coverage, possible compression of the WEB base, and interaction with the parent vessel. If the configuration is unsatisfactory, catheter position or angulation can potentially be modified and the implant reassessed before irreversible detachment. Adjunctive strategies should also remain available: balloon assistance may help maintain appropriate device direction, while a stent or additional microcatheter can provide rescue or support when neck coverage or stability is problematic.

The demonstrated case also illustrates that limited protrusion toward the parent vessel should be interpreted in context rather than automatically considered technical failure. Its significance depends on the degree of protrusion, vessel caliber and flow, final implant configuration, and associated thromboembolic considerations. In the presented PCA case, the faculty discusses these factors together with antiplatelet management. Approximately 30 days of aspirin was used in that particular case, followed by imaging surveillance; this should be understood as case-specific management rather than a universal regimen, since antiplatelet requirements may differ according to parent-vessel exposure and the use of adjunctive devices such as stents.

The six-month follow-up shown during the session was described by the faculty as a “class 1” result, consistent with complete aneurysm occlusion. Particularly instructive was the apparent recovery of device geometry after detachment, supporting the concept that catheter-induced deformation may resolve once external constraint is removed. Overall, the demonstration shows that successful intrasaccular therapy depends on integrating aneurysm morphology, parent-vessel orientation, catheter trajectory, accurate sizing, device mechanics, and controlled neck reconstruction. Simulation can help anticipate the final configuration, but it should complement rather than replace careful angiographic assessment before detachment. For operators beginning with the technique, stable guidewire-assisted catheterization, conservative case selection, accurate sizing, and readiness for balloon, stent, or additional-microcatheter assistance remain particularly important.