Association between perforator stroke after middle cerebral artery elective stenting and arterial remodeling patterns: a high-resolution MRI-based retrospective cohort study

Abstract

Background: Patterns of arterial remodeling may be associated with outcomes in patients with severe middle cerebral artery (MCA) stenosis after endovascular treatment (EVT). This study aims to investigate the potential correlation between arterial remodeling patterns in patients with severe MCA stenosis, and plaque characteristics and procedure-related perforator stroke (PS).

Methods: Consecutive patients with MCA atherosclerotic disease who underwent EVT at the First Affiliated Hospital of Zhengzhou University from January 2018 to June 2023 were retrospectively enrolled in this study. The clinical and surgical data of the patients were evaluated. Remodeling index values >1.05, 0.95-1.05, and <0.95 indicated positive remodeling (PR), intermediate remodeling (IR), and negative remodeling (NR), respectively. Based on the remodeling index values calculated by high-resolution magnetic resonance imaging (HR-MRI), the arterial remodeling patterns were classified as NR or non-NR; non-NR was defined as both PR and IR. The primary endpoint was procedure-related PS. Plaque characteristics included the plaque area, plaque burden, contrast-enhancement ratio, and plaque distribution. Plaque features and the incidence of procedure-related PS were compared between the NR and non-NR groups. Differences in the categorical variables between the patients with NR and non-NR were assessed using the Chi-square test (χ²) or Fisher's exact test. Differences in the continuous variables between the two groups were assessed using the Student t-test or Mann-Whitney U-test.

Results: A total of 65 patients (mean age: 57.6 years) were enrolled in the study. Of the patients, 45 (69.2%) showed NR and 20 (30.8%) showed non-NR. The primary endpoint of procedure-related PS occurred in 3 patients (3/65, 4.6%). On HR-MRI, the entire cohort had a mean plaque area of 10.0 mm², a mean plaque burden of 92.0 %, and a mean enhancement ratio of 1.3. Compared to the non-NR group, the NR group had a smaller plaque area (9.2 vs. 11.6 mm², P=0.001). The probability of the primary end point was 15.0% in the non-NR group and 0.0% in the NR group (P=0.026).

Conclusions: PS after MCA elective stenting may be related to non-NR based on HR-MRI. Further prospective and multicenter studies need to be conducted to confirm these findings.

Keywords: Perforator stroke (PS); arterial remodeling; magnetic resonance imaging (MRI); middle cerebral artery stenosis.

Figure 1

Flowchart of patient inclusion and exclusion criteria for this study. MCA, middle cerebral artery; EVT, endovascular treatment; HR-MRI, high-resolution magnetic resonance imaging.

Figure 2

One adult patient with symptomatic severe MCA stenosis, refractory to medical treatment. (A) DSA showed severe stenosis (arrow) of the M1 segment of the right MCA. (B) After the MCA stenting, the vascular lumen in the lesion was substantially improved. (C) The stenosis was measured on a longitudinal MCA image, and the remodeling index was calculated by dividing the vessel area of the site with the narrowest lumen (arrow, straight line MLN) by the area of the reference site (dashed line Ref). (D) The remodeling index was 1.04, and it was classified as non-negative remodeling. (E) Preoperative DWI revealed no evidence of an infarction. (F) Postoperative DWI showed a cerebral infarction (arrow) in the right caudate nucleus and the internal capsules, which are supplied by the perforator arteries of MCA. MLN, maximal lumen narrowing; Ref, reference; LA, lumen area; VA, vessel area; MCA, middle cerebral artery; DSA, digital subtraction angiography; DWI, diffusion weighted imaging.

Figure 3

One adult patient with symptomatic severe MCA stenosis, refractory to medical treatment. (A) DSA showed severe stenosis (arrow) of the M1 segment of the right MCA. (B) After the MCA stenting, the vascular lumen in the lesion was substantially improved. (C) The stenosis was measured on a longitudinal MCA image, and the remodeling index was calculated by dividing the vessel area of the site with the narrowest lumen (arrow, straight line MLN) by the area of the reference site (dashed line Ref). (D) The remodeling index was 0.65, and it was classified as negative remodeling. (E) Preoperative DWI revealed no evidence of an infarction. (F) Postoperative DWI showed no evidence of a new infarction. MLN, maximal lumen narrowing; Ref, reference; LA, lumen area; VA, vessel area; MCA, middle cerebral artery; DSA, digital subtraction angiography; DWI, diffusion weighted imaging.