Contemporary Neurovascular Guidelines Between Historical Evidence and Technological Reality

Recent European guidelines on aneurysmal subarachnoid hemorrhage represent an important effort toward standardization of neurovascular care [1].However, several recommendations concerning contemporary endovascular treatment strategies also highlight broader methodological challenges regarding the interpretation and weighting of evidence across treatment modalities over time.Modern endovascular techniques such as balloon-assisted coiling (BAC) and intrasaccular flow disruption devices are frequently evaluated against exceptionally high evidentiary thresholds despite being supported by prospective multicenter registries, pooled analyses, and core lab-adjudicated studies demonstrating favorable safety and efficacy profiles [2-5].In contrast, historical surgical paradigms and concepts originating from the early coiling era continue to exert substantial influence on current these recommendations [1].This imbalance is particularly evident in the interpretation of BAC-related evidence.Two early single-center reports from the initial adoption era of balloon remodeling-the studies by Sluzewski et al. and Henkes et al.-receive substantial interpretative emphasis despite important methodological limitations including small sample size, heterogeneous procedural workflows, firstgeneration devices, and considerable selection bias [6,7].In contrast, more contemporary positive prospective multicenter evidence such as CLARITY is interpreted more cautiously despite substantially greater methodological robustness and closer relevance to current neurointerventional practice [2].A similarly illustrative example concerns the interpretation of intrasaccular flow disruption devices.The guideline states that available studies lacked core laboratory adju-