Elsevier

World Neurosurgery

Volume 108, December 2017, Pages 236-243
World Neurosurgery

Original Article
Quantitative Analysis of Intracranial Vertebrobasilar Dissecting Aneurysm with Intramural Hematoma After Endovascular Treatment Using 3-T High-Resolution Magnetic Resonance Imaging

https://doi.org/10.1016/j.wneu.2017.08.161Get rights and content

Objective

Quantitative measurements of intracranial vessel walls are reliable in 3-T high-resolution magnetic resonance imaging (HR-MRI). However, few reports have assessed the arterial wall after endovascular treatment (EVT) by 3-T HR-MRI. This study aimed to quantitatively analyze vessel walls in vertebrobasilar artery dissecting aneurysms after EVT.

Methods

From May 2012 to December 2015, a total of 21 patients with 21 intracranial vertebrobasilar dissecting aneurysms (VBDAs) were enrolled in this consecutive study. All the VBDAs were characterized by intramural hematomas (IMHs ≥5 mm) and treated with reconstructive EVT. Images of preoperative and follow-up 3-T HR-MRI were used to evaluate the arterial wall. The relative signal intensity (RSI) of IMHs was quantified on T1-weighted imaging (T1WI) and magnetization-prepared rapid acquisition gradient-echo (MPRAGE).

Results

Angiographic follow-up was performed for a mean of 9.19 ± 3.22 months. According to angiographic results at follow-up, 21 patients were divided into 2 groups (progressive group, n = 6; stable group, n = 15). In the progressive group, RSI of IMHs was significantly increased on MPRAGE of follow-up 3-T HR-MRI compared with that before treatment (P < 0.05), and the difference was not significant on T1WI. However, in the stable group, RSI of IMHs was significantly reduced after treatment (P < 0.05).

Conclusions

Persistent high signal intensity of IMHs in VBDAs after reconstructive EVT may be associated with the progression of VBDAs. It may also indicate an unsteady state of the aneurysm, which suggests that reconstruction of the parent artery is not satisfactory.

Introduction

Spontaneous intracranial vertebrobasilar dissecting aneurysm (VBDA) is a rare and challenging disease, which may result in stroke in young and middle-aged adults.1 In recent years, VBDA has been increasingly recognized because of growing familiarity with its clinical syndrome and obvious improvements in neurovascular imaging.2, 3, 4 Digital subtraction angiography (DSA) is used for diagnosis and follow-up of arterial dissection. However, DSA does not allow visualization of the arterial wall. High-resolution magnetic resonance imaging (HR-MRI) can depict the arterial wall and confirm the diagnosis of dissection.5 Numerous studies have shown quantitative dissection findings of intracranial artery dissection using 3-T HR-MRI.6, 7 In these studies, T1-weighted imaging (T1WI) was used to quantify the relative signal intensity (RSI) of intramural hematoma (IMH) because hyperintensity on T1WI generally represents hemorrhage on HR-MRI.8, 9, 10 RSI changes of IMHs may be related to the prognosis of intracranial VBDAs after endovascular treatment (EVT). However, few reports have assessed reconstruction of the arterial wall after EVT by 3-T HR-MRI. How IMHs change after treatment remains unknown.

Therefore, our study aimed to quantitatively analyze IMHs on T1-weighted sequences between preoperative and follow-up HR-MRI. Our findings may provide important information on the prognosis of intracranial VBDA after EVT.

Section snippets

Patient Selection

This retrospective study was approved by our institutional ethical committee. Written informed consent was obtained from the patients or their family members during hospitalization. From May 2012 to December 2015, a total of 21 patients with 21 VBDAs were enrolled in this consecutive study according to the following criteria: 1) patients who were diagnosed with VBDA according to DSA and HR-MRI; 2) unequivocal evidence by HR-MRI (IMH ≥5 mm on the perpendicular plane to the long axis of the

Results

After application of screening criteria, 21 patients with 21 intracranial VBDAs were included and divided into 2 groups (progressive group: n = 6; stable group: n = 15) according to angiographic results at follow-up. All cases in our study were unruptured and treated with reconstructive EVT. Among 21 patients, 17 patients were treated with stent-assisted coiling (single stent: n = 6; double stents: n = 10; 4 stents: n = 1) and 4 patients underwent stent alone treatment (single stent: n = 1;

Discussion

IMH usually results from extensive damage of the internal elastic lamina and penetration of blood into the vessel wall, or from a rupture of neovessels.11 Nakatomi et al.12 suggested that formation of IMHs is a critical event that is necessary for a dissecting aneurysm to become symptomatic and progress. Therefore, quantitative assessment of IMH in VBDAs may be helpful in establishing management and prediction of prognosis. However, less attention has been paid to changes in IMHs after EVT.

Conclusions

The technique of 3-T HR-MRI can offer clear visualization of features of the vessel wall. Persistent high signal intensity and the degree of enhancement of IMHs in VBDAs after reconstructive EVT may be associated with progression of VBDAs. It may also indicate an unsteady state of the aneurysm, which suggests that reconstruction of the parent artery is not satisfactory, and that careful attention should be provided for management of VBDAs. Additional studies are needed to assess these findings.

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    • Cited by (5)

    Conflict of interest statement: This work was supported by the National Key Research and Development Plan of China (2016YFC1300800); the National Natural Science Foundation of China (81301003, 81301193, 81371315, 81471167, 81671139, and 81220108007); and the Special Research Project for Capital Health Development (2014-1-1071).

    Xinjian Yang and Binbin Sui contributed equally to this work.

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