Impact of the Internal Carotid Artery Morphology on in silico Stent-Retriever Thrombectomy Outcome

Abstract

The aim of this work is to propose a methodology for identifying relationships between morphological features of the cerebral vasculature and the outcome of in silico simulations of thrombectomy, the mechanical treatment for acute ischemic stroke. Fourteen patient-specific cerebral vasculature segmentations were collected and used for geometric characterization of the intracranial arteries mostly affected by large vessel occlusions, i.e., internal carotid artery (ICA), middle cerebral artery (MCA) and anterior cerebral artery (ACA). First, a set of global parameters was created, including the geometrical information commonly provided in the clinical context, namely the total length, the average diameter and the tortuosity (length over head-tail distance) of the intracranial ICA. Then, a more exhaustive geometrical analysis was performed to collect a set of local parameters. A total of 27 parameters was measured from each patient-specific vascular configuration. Fourteen virtual thrombectomy simulations were performed with a blood clot with the same length and composition placed in the middle of the MCA. The model of TREVO ProVue stent-retriever was used for all the simulations. Results from simulations produced five unsuccessful outcomes, i.e., the clot was not removed from the vessels. The geometric parameters of the successful and unsuccessful simulations were compared to find relations between the vascular geometry and the outcome. None of the global parameters alone or combined proved able to discriminate between positive and negative outcome, while a combination of local parameters allowed to correctly identify the successful from the unsuccessful simulations. Although these results are limited by the number of patients considered, this study indicates a promising methodology to relate patient-specific geometry to virtual thrombectomy outcome, which might eventually guide decision making in the treatment of acute ischemic stroke.

A Review of the Advancements in the in-vitro Modelling of Acute Ischemic Stroke and Its Treatment

“…In addition to physical models, computational modeling is gaining attention and likely to have an increasing role in medical device development ( 57 , 90 – 92 ). Finite element modeling is recommended by the FDA, in the guidance for non-clinical testing of stents and associated delivery systems, as a means of performing stress and fatigue analysis on the devices seeking approval ( 93 ).…”

“…Recent publications from the INSIST project (IN- Silico trials for treatment of acute Ischemic Stroke) report the development of a platform where computational simulations of thrombosis and thrombolysis, thrombectomy, perfusion, and brain tissue infarction are carried out on “virtual patients” ( 57 , 94 ). These “virtual patients” include clinically representative characteristics such as clot properties, vessel geometries, and clinical record.…”

“… Illustrations of anatomical tortuosity in (A) the ICA and (B) the carotid siphon. Reproduced from ( 56 , 57 ) with permission. …”

“…Such anatomical features are common among patients with acute ischemic stroke (AIS), affecting both the intra- and extra-cranial vasculature. Significant variability in ICA geometry can be found in the carotid siphon, which lies between the carotid canal and the ICA-terminus, where the ICA bifurcates into the middle cerebral artery (MCA) and the anterior cerebral artery (ACA] ( 57 ). Tortuosity of the ICA has been identified as an impediment to multiple types of endovascular procedures.…”

Anatomical characteristics and morphometric analyses of the internal carotid artery using retrospective angiographic images

“…These segments consist of a C1 (cervical), C2 (petrous or horizontal), C3 (lacerum), C4 (cavernous), C5 (clinoid), C6 (ophthalmic or supraclinoid), and C7 (communicating or terminal) parts. Many studies have reported that anatomical variations of the ICA can be associated with various neurovascular diseases and thus, can consequently complicate endovascular and surgical approaches [4,10,12,14,16,18,21]. For example, variant ICAs have been reported to result in complications during treatment of traumatic cavernous sinus stulas (TCCF) [5,13,22].…”