Computational Fluid Dynamic Simulation of a Giant Basilar Tip Aneurysm with Eventual Rupture After Hunterian Ligation

BACKGROUND: Hunterian ligation is performed to reduce and to change the flow of an aneurysm; it is a surgical option for a complex aneurysm that cannot be managed by either clipping or coiling. However, it may be associated with adverse effects. This study was carried out to analyze how Hunterian ligation changed the flow dynamics of a particular cerebral aneurysm. METHODS: A case of giant basilar tip aneurysm, in which Hunterian ligation resulted in rupture 6 months later, was subjected to computational fluid dynamic simulation. Among the simulations with various boundary conditions, the flow dynamic parameters of streamlines, velocities, and wall shear stresses were compared and analyzed qualitatively and quantitatively. RESULTS: Hunterian ligation switched the parent artery from the basilar artery to the left posterior communicating artery. The changes in the direction and the diameter of the parent arteries resulted in the focal elevation of the shear magnitude and the high shear gradient on the posterior wall of the aneurysm after the ligation. These hemodynamic changes might have been associated with the eventual rupture of the aneurysm. CONCLUSIONS: Hunterian ligation is a useful flow diversion surgery, but it might worsen the flow dynamics in specific cases.