PRECISION ENDOVASCULAR RECONSTRUCTION OF INTRACRANIAL ANEURYSMS: FLOW DIVERSION, INTRASACCULAR FLOW DISRUPTION, SURFACE- MODIFIED DEVICES, AND PATIENT-SPECIFIC DEVICE SELECTION

Abstract

Background. Endovascular  management  of  intracranial  aneurysms  has  shifted  from mechanical filling of the aneurysm sac toward biological reconstruction of the parent artery and controlled modification of intra-aneurysmal hemodynamics. Flow-diverting stents and intrasaccular flow-disruption devices have expanded treatment options for large, giant, fusiform, recurrent, and wide-neck  bifurcation  aneurysms  that  are  technically  challenging  for  conventional  coiling  or microsurgical clipping. Contemporary practice increasingly requires selection between parent-vessel flow diversion and intrasaccular treatment rather than universal use of a single implant.Materials and Methods. A structured narrative review was performed using prospective pivotal trials, randomized studies, multicenter registries, long-term device studies, and contemporary clinical investigations available through August 2026. Pipeline, Surpass, FRED/FRED X, Pipeline Shield, Pipeline Vantage, Woven EndoBridge, Contour, and emerging intrasaccular technologies were evaluated. Particular attention was directed toward aneurysm morphology, vessel reconstruction, branch  preservation,  delayed  occlusion,  antiplatelet  therapy,  surface  modification,  incomplete occlusion, retreatment, ruptured aneurysms, posterior circulation lesions, and device-specific treatment geometry.Results. Flow diversion provides progressive aneurysm exclusion through reduction of inflow, intra-aneurysmal thrombosis, and endothelial reconstruction across the aneurysm neck. Long-term studies demonstrate progressive occlusion after Pipeline and Surpass treatment, although efficacy and complication profiles vary substantially according to aneurysm location and morphology. Small and medium  unruptured  aneurysms  can  be  treated  with  high  effectiveness  in  appropriately  selected patients, but flow diversion requires a parent artery suitable for implantation and usually mandates antiplatelet therapy. Intrasaccular devices provide a fundamentally different strategy by disrupting flow  at  or  within  the  aneurysm  neck  without  reconstructing  the  parent  artery.  The  WEB  has demonstrated durable five-year safety and effectiveness for wide-neck bifurcation aneurysms, and prospective data support its use in selected ruptured aneurysms. Newer neck-bridging intrasaccular systems such as Contour and Artisse further expand this concept. Surface-modified flow diverters may reduce device thrombogenicity and facilitate simplified antiplatelet strategies, although routine single- antiplatelet treatment has not yet become a universal standard.Conclusion. Intracranial aneurysm therapy is evolving toward precision device selection based on  aneurysm  geometry,  parent-vessel  anatomy,  bifurcation  architecture,  rupture  status,  branch incorporation, expected healing mechanism, and antiplatelet tolerance. The future objective is not to select  the  most  technologically  advanced  implant,  but  to  choose  the  device  whose  biological mechanism best matches the individual aneurysm.