Imbalanced flow changes of distal arteries: An important factor in process of delayed ipsilateral parenchymal hemorrhage after flow diversion in patients with cerebral aneurysms

Abstract

Background and objective Hemodynamic forces may play a role in symptomatic delayed ipsilateral parenchymal hemorrhage (DIPH) of intracranial aneurysm (IA) after flow diverter placement. We aimed to investigate the hemodynamic risk factors in the postsurgical DIPH process. Methods Six patients with internal carotid artery (ICA) aneurysm developed to DIPH and 12 patients without DIPH (1:2 matched controls) after flow diverter were included between January 2015 to January 2019. Postsurgical hemodynamics of distal arteries (terminal ICA, middle cerebral artery (MCA), anterior cerebral artery (ACA)) were investigated using computational fluid dynamics, as well as the hemodynamic alteration between pre- and post-treatment. The DIPH related and unrelated distal arteries (either MCA or ACA) were discriminated and compared. Definition of imbalance index is the difference in increased velocity post-flow diverter between MCA and ACA and was used to evaluate the blood flow distribution of distal arteries. Results The mean and maximum flow velocities in the terminal ICA increased significantly after treatment in both groups. In DIPH group, the increase rate of mean velocity in the DIPH-related artery was significantly higher than that in DIPH-unrelated artery after the treatment (20.98 ± 15.38% vs −6.40 ± 7.74%; p = 0.028). Between the DIPH and control group, the baseline characteristics were well matched. However, a higher imbalance index of mean velocity was found in DIPH group (27.38 ± 13.03% vs 10.85 ± 14.12%; p = 0.031). Conclusion The mean velocity of DIPH related artery increased more, and the imbalance in increased blood flow distribution of distal arteries might play an important role in DIPH after flow diverter of IAs.

Methylprednisolone is related to lower incidence of postoperative bleeding after flow diverter treatment for unruptured intracranial aneurysm

“…Brunozzi et al reported that the mean ipsilateral middle cerebral artery flow velocity was increased significantly in patients suffering from delayed ipsilateral parenchymal hemorrhage ( Brunozzi et al, 2018 ). Similar results were also reported by Li et al, that the mean velocity of arteries related to delayed ipsilateral parenchymal hemorrhage was increased and the imbalance in blood flow distribution of distal arteries might play an important role, after FD treatment for UIAs ( Li et al, 2021 ). Li et al showed that an unstable flow pattern and high energy loss within released FD may be important hemodynamic risk factors related to PB ( Li et al, 2019 ).…”

How to perform intra-aneurysmal coil embolization after Pipeline deployment: a study from a hemodynamic viewpoint

“…Various complications have also been described when using FDs 14 15. Postoperative delayed rupture of IAs is a fatal complication.…”

Classification and hemodynamic characteristics of delayed intracerebral hemorrhage following stent-assisted coil embolism in unruptured intracranial aneurysms

“…Symptomatic delayed intracerebral hemorrhage (DICH) emerges as a grave postoperative complication following flow diverter (FD) interventions for intracranial aneurysms, characteristically manifesting hours to days subsequent to the procedure, with intracerebral hemorrhage (ICH) occurring in the distal area of the parent artery, precipitating gradual neurological decline ( 1 , 2 ). However, our study found that DICH can also afflict patients with unruptured UIAs undergoing stent-assisted coil (SAC) embolization.…”

“…Presently, the causes and pathogenesis of this life-threatening complication remain elusive, with prediction yet unattainable ( 3–5 ). Various pathophysiological conjectures have been posited for DICH, with dual antiplatelet therapy (DATP) being a predominant factor ( 2 , 24 , 25 ), alongside hemorrhagic transformation of cerebral infarctions ( 2 , 6 , 7 ), occlusive embolic events ( 22 ), and hemodynamic shifts ( 1 , 4 , 5 , 22–23 ). Specifically, the hemorrhagic risk associated with SAC for UIAs under DATP is documented between 2.2% and 2.6% ( 28 , 26 ), and the hyper-responsiveness of clopidogrel for antiplatelet effects significantly increases the risk of bleeding in endovascular procedures ( 10 , 8 ).…”

“…Specifically, the hemorrhagic risk associated with SAC for UIAs under DATP is documented between 2.2% and 2.6% ( 28 , 26 ), and the hyper-responsiveness of clopidogrel for antiplatelet effects significantly increases the risk of bleeding in endovascular procedures ( 10 , 8 ). Hemodynamic modifications in the distal parent artery post-FD are also implicated in DICH pathogenesis ( 1 , 5 , 12–14 ), yet their occurrence post-SAC remains unstudied. Employing computational fluid dynamics (CFD), our study probes the hemodynamic alterations in DICH-related artery of the distal branch post-SAC treatment, seeking insights into the underlying mechanism.…”