Sequential Hemodynamic Analysis of Ruptured Posterior Communicating Artery Aneurysms Treated With Coil Embolization and Delayed Flow Diversion.

Background and objectives: Computational fluid dynamics has advanced our knowledge of the pathogenesis of intracranial aneurysms and the dynamic changes observed after treatment. Herein, we analyze hemodynamic changes throughout the intervention stages for ruptured posterior communicating artery (PComA) aneurysms, treated with acute coiling and delayed flow diversion (FD).

Methods: We performed a retrospective analysis of ruptured PComA aneurysms treated with the acute coiling and delayed FD strategy between June 2013 to November 2022, using 3-dimensional reconstructions of digital subtraction angiographies. Hemodynamic simulations using ANSYS® calculated aneurysmal and adjacent arteries' wall shear stress (WSS), aneurysmal low shear areas (LSA), and mean velocities in the distal arteries.

Results: Six of the 22 patients were selected for computational fluid dynamics analysis, including 4 females and 2 males with a median age of 60 years. The average aneurysm volume was 984.12 mm3, with an average surface area of 386.11 mm2; LSA was 22.90%, and the average WSS was 3.39 Pa. The 2 largest aneurysms also had the highest LSA values. After coiling, there was a reduction in the aneurysmal volume (-78.42%) and the average surface area (-55.28%), and aneurysmal WSS increased to 6.10 Pa (+79.90%). WSS values for the middle cerebral artery (MCA) increased to 10.76 Pa, while anterior cerebral artery (ACA) increased to 7.51 Pa. Complete occlusion was achieved with delayed FD at a median follow-up of 19.7 months. After FD, average WSS increased to 14.94 Pa for the MCA (+70.64%) and to 10.82 Pa for the ACA (+30.10%). The mean MCA velocity increased to 43.04 cm/s (+36.85%), and 3 cases showed an increase in ACA velocities.

Conclusion: LSA may have triggered rupture for the PComA aneurysms analyzed. After coiling, average WSS increased in the aneurysm wall and downstream vessels in the majority of cases analyzed. Delayed FD caused hemodynamic disturbances distal to deployment, reflected in the sequential increase in the WSS and velocities in both the ACA and MCA.