Follow-up evaluation of dissecting aneurysms of the vertebrobasilar circulation by using gadolinium-enhanced magnetic resonance imaging

Endovascular treatment of acute intracranial vertebral artery dissection: long-term follow-up results of internal trapping and reconstructive treatment using coils and stents

BACKGROUND

Endovascular internal trapping is an effective procedure for the treatment of acute vertebral artery dissection (VAD). However, the outcomes of reconstructive treatment have not been well established. The aim of our study is to evaluate the long-term clinical and angiographic results of endovascular internal trapping or reconstructive treatment of acute VAD.

METHODS

Between 2005 and 2013, 26 patients with acute VAD were managed with internal coil trapping (n=10), stent-assisted coiling (n=14), stent only (n=1), and proximal occlusion (n=1). Stent-assisted coiling included the modified stent-assisted semi-jailing technique (n=10), balloon-in-stent technique (n=2), and coiling followed by balloon mounted stent (n=2). Digital subtraction angiography (DSA) was performed in all patients except for three who died during the acute stage.

RESULTS

Of 26 patients with VAD, 14 and 12 presented with hemorrhagic and non-hemorrhagic types, respectively. The dominancy of the relevant artery was defined as dominant (n=9), even (n=12), and non-dominant (n=5). Reconstructive treatment was performed in six patients with ruptured VADs which failed balloon test occlusion and nine with non-hemorrhagic VADs. Clinical outcomes were favorable in 22 (84.6%), severe disability occurred in one, and there were three deaths (11.5%). All patients except the three who died had angiographic follow-up at 6-32 months (mean 10.4 months). The angiographic results of nine cases of internal trapping and one of proximal occlusion all showed a stable occlusion state. Among the 15 cases of reconstructive treatment, follow-up DSAs were available for the 13 surviving patients, 10 of which demonstrated stable occlusion of aneurysmal dilation and patent parent artery.

CONCLUSIONS

This study suggests that internal trapping is a stable and effective treatment for acute VAD. Reconstructive treatment using stent and coils could also be a feasible alternative modality for hemorrhagic type VAD. However, serial DSA follow-up is essential.

Basi-parallel anatomical scanning magnetic resonance imaging in patients with bilateral vertebrobasilar artery dissections

A 31-year-old man presented with bilateral unruptured vertebral artery (VA) dissections. The temporal course of the dissected arteries was successively evaluated using brain surface imaging modality basi-parallel anatomical scanning (BPAS) magnetic resonance (MR) imaging in combination with the conventional modalities of MR angiography and three-dimensional computed tomography (3D-CT) angiography. Initially, BPAS-MR imaging clearly demonstrated bilateral fusiform dilatations of the arterial wall, whereas MR angiography and 3D-CT angiography showed irregular, dilated, or interrupted inner contour of the arteries. Finally, BPAS-MR imaging demonstrated resolution of both aneurysms, and MR angiography demonstrated obstruction of the left VA and normal contours of the right VA. Combination of diagnostic tools such as BPAS-MR imaging and MR angiography is useful for evaluating the exact nature of dissected arteries and determining the temporal course.

Cerebrovascular Dissections—A Review Part I: Spontaneous Dissections

Spontaneous cerebrovascular dissections are subintimal or subadventitial cervical carotid and vertebral artery wall injuries and are the cause of as many as 2% of all ischemic strokes. Spontaneous dissections are the leading cause of stroke in patients younger than 45 years of age, accounting for almost one fourth of strokes in this population. A history of some degree of trivial trauma is present in nearly one fourth of cases. Subsequent mortality or neurological morbidity is usually the result of distal ischemia produced by emboli released from the injury site, although local mass effect produced by arterial dilation or aneurysm formation also can occur. The gold standard for diagnosis remains digital subtraction angiography. Computed tomography angiography, magnetic resonance angiography, and ultrasonography are complementary means o evaluation, particularly for injury screening or treatment follow-up. The annual rate of stroke after injury is approximately 1% or less per year. The currently accepted method of therapy remains antithrombotic medication, either in the form of anticoagulation or antiplatelet agents; however, no class I medical evidence exists to guide therapy. Other options for treatment include thrombolysis and endovascular therapy, although the efficacy and indications for these methods remain unclear.

Imaging the vertebral artery

Although conventional intraarterial digital subtraction angiography remains the gold standard method for imaging the vertebral artery, noninvasive modalities such as ultrasound, multislice computed tomographic angiography and magnetic resonance angiography are constantly improving and are playing an increasingly important role in diagnosing vertebral artery pathology in clinical practice. This paper reviews the current state of vertebral artery imaging from an evidence-based perspective. Normal anatomy, normal variants and a number of pathological entities such as vertebral atherosclerosis, arterial dissection, arteriovenous fistula, subclavian steal syndrome and vertebrobasilar dolichoectasia are discussed.

Ischemic Basilar Artery Dissecting Aneurysm Treated by Stenting Only-Case Report-

A 45-year-old man presented with enlargement of basilar artery dissecting aneurysm 10 months after suffering brain stem infarction. Combined stenting and placement of Guglielmi detachable coils (GDCs) was planned to obliterate the aneurysm sac. Stent deployment was performed but the procedure was halted to avoid overdosing with contrast material. Cerebral angiography 10 days later showed thrombosis of the aneurysm sac and normalization of the blood flow in the basilar artery. The patient has been followed up for 2 years and showed good clinical and angiographic outcome. Stenting results in obliteration of the aneurysm sac, so a two-stage procedure is recommended.

Ruptured vertebral artery dissecting aneurysm associated with parent artery occlusion

A 63-year-old hypertensive man presented with vertebral artery (VA) dissection manifesting as subarachnoid hemorrhage located mainly in the posterior fossa. Left vertebral angiography on the day of hemorrhage showed complete occlusion of the left VA. Right vertebral angiography showed retrograde filling of the distal portion of the left VA and the left posterior inferior cerebellar artery, and a "double lumen"-like finding in the left VA. He was managed conservatively. Follow-up angiography on Day 29 showed spontaneous recanalization of the occlusive lesion and an almost normal arterial configuration. T2-weighted magnetic resonance (MR) imaging on Day 45 revealed multiple infarctions in the brainstem. T1-weighted MR imaging showed a high intensity area, suggestive of intramural hematoma, in the left VA. He was transferred to another hospital in a persistent vegetative state.

Vertebrobasilar artery dissection presenting with simultaneous subarachnoid hemorrhage and brain stem infarction: case report

BACKGROUND

Intracranial dissecting aneurysms have been associated with subarachnoid hemorrhage (SAH) or cerebral ischemia. We encountered a patient presenting with simultaneous subarachnoid hemorrhage and brainstem infarction caused by a dissecting aneurysm of the vertebrobasilar artery, which was diagnosed by magnetic resonance imaging (MRI) but did not show abnormal findings on cerebral angiography.

CASE DESCRIPTION

A 55-year-old man had sudden onset of headache and left abducens palsy. Computed tomography revealed a subarachnoid hemorrhage localized in the left prepontine cistern and the left cerebellomedullary fissure. Cerebral angiography showed neither a saccular aneurysm nor fusiform dilatation causing the subarachnoid hemorrhage. MRI demonstrated a small infarction in the left dorsal pons, and an intramural hematoma of the left vertebral artery and lower basilar artery.

CONCLUSION

This is a rare case of a vertebrobasilar dissecting aneurysm that simultaneously caused both SAH and brain stem infarction. MRI should be performed in the acute phase of SAH of unknown origin to determine the possible coexistence of a dissecting aneurysm, as occurred in this case.

Management of intracranial vertebral artery dissections initially presenting without subarachnoid hemorrhage

OBJECTIVE

The clinical and angiographic follow-up results for intracranial vertebral artery (VA) dissections that initially presented without subarachnoid hemorrhage (SAH) were retrospectively investigated, to clarify their management.

METHODS

Twenty-one patients with VA dissections that initially presented without SAH were studied. Initial angiography revealed aneurysmal dilation in 11 cases (typical pearl-and-string sign in 8 cases, aneurysmal dilation only in 2, and aneurysmal dilation with double-lumen sign in 1), occlusion in 7, double-lumen sign in 2, and string-like stenosis in 1. Nine patients (six with pearl-and-string sign, one with occlusion with aneurysmal dilations, and two with double-lumen sign), including three patients who experienced subsequent SAH, underwent endovascular proximal parent artery occlusion. The other 12 patients were treated conservatively. All patients were monitored with magnetic resonance angiography or digital subtraction angiography.

RESULTS

Three patients experienced subsequent SAH, 1 day (two patients) or 51 months after onset. Follow-up angiographic assessments of the 20 patients demonstrated complete resolution in five cases, reduction of aneurysmal dilation in one case, and partial recanalization in one case. However, enlargement or formation of an aneurysmal dilation was recognized in four cases and progression of dissection was observed in one case. Eighteen patients experienced good recoveries, and three patients demonstrated moderate disabilities as a result of the initial ischemic insult.

CONCLUSION

The risk of bleeding from unruptured VA dissections is higher than previously considered. Therefore, endovascular treatment should be considered for patients with VA dissections with relatively large or growing aneurysmal dilations.

Spontaneous dissecting aneurysms of anterior and middle cerebral artery associated with brain infarction: a case report and review of the literature

BACKGROUND

Intracranial dissecting aneurysms have been reported with increasing frequency and are recognized as a common cause of stroke. In some reviews and case reports, attempts have been made to compare the outcomes of surgical and medical treatments. However, the appropriate management of dissecting aneurysms in the anterior circulation remains controversial, especially in patients who also manifest cerebral infarction.

CASE DESCRIPTION

A 45-year-old male was diagnosed as having a dissecting aneurysm of the right middle cerebral artery (MCA) with cerebral infarction. In the course of conservative treatment, he developed a new cerebral infarction in the territory of the right anterior cerebral artery (ACA). Repeat cerebral angiograms revealed an increase in the aneurysmal dilatation of the right M2 and the appearance of a segmental dilatation of the right A2. He continued to be treated conservatively and his course was satisfactory. On subsequent angiograms, we observed resolution of the right A2 dissection and no further progression of the dilatation of the right M2.

CONCLUSION

This is the first reported case of simultaneous idiopathic dissecting aneurysms of different major arterial branches in the anterior circulation. Our review of the literature disclosed 36 and 23 cases, respectively, of dissecting aneurysms of the ACA and MCA. Many previously reported patients with these dissecting aneurysms involving subarachnoid hemorrhage (SAH) underwent surgery, which resulted in better outcome. More than half of the patients with ACA and MCA dissecting aneurysms had cerebral infarction. All ACA dissecting aneurysms involving ischemia occurred in the A2 region. The outcomes of both surgical and conservative management were equally satisfactory. On the other hand, in patients with MCA dissecting aneurysms, the area of ischemia frequently involved the M1 region; in these patients, conservative treatment resulted in poor outcomes. Therefore, revascularization distal to the compromised artery should be considered in patients with MCA-dissecting aneurysms who have ischemia. Careful interpretation of serial angiograms and/or magnetic resonance (MR) images is necessary because of the possibility of disease progression. If the aneurysmal size increases or there is progression of ischemic symptoms in the course of conservative treatment, surgery must be urgently evaluated.

Mr angiography in cerebrovascular disease

MR angiography has become a realistic diagnostic option for patients with neurovascular disease. MR angiography is not a single imaging sequence, but a collection of related methods for obtaining angiographic data. As a guide for practice, we review the literature on MR angiography in a spectrum of neurovascular indications with particular attention paid to choice of technique. The principles underlying the different techniques available are also presented. Summers, P. E.et al.

The usefulness of 3D-CT angiography for the diagnosis of spontaneous vertebral artery dissection-report of two cases

Spontaneous vertebral artery dissection (VAD) has been recognized as being more common than was first thought, with the growing use of magnetic resonance imaging (MRI). However, simple MRI alone is not always satisfactory for making an accurate diagnosis. We experienced two cases of VAD in our clinic, in which three-dimensional computed tomographic angiography (3D-CTA) was performed. Our scanner has the capability of examining a slice of 1mm thick, 0.5mm reconstruction pitch, and a scan time of 1s/rotation. 3D-CTA clearly demonstrated the stenotic change concomitant with the surrounding thrombus and was thought to be useful for making an accurate diagnosis.

3D MR angiography of the entire aorta: modified application of the body-phased array coil for a single-shot technique

OBJECTIVE

Evaluation of different contrast-enhanced MR angiography imaging protocols for visualization of the entire aorta in breath-hold technique.

METHODS AND PATIENTS

Three different CE (0.15 mmol/kg) MRA protocols were evaluated by phantom and patient studies: (1) two separate MRA with conventional application of the body-phased array coil; (2) a single-shot MRA with modified application of the body-phased array coil; (3) a single-shot MRA with the body coil. Duplex sonography, CTA and DSA were used as standard of reference.

RESULTS

In all examinations the entire aorta could be visualized. The best SNR was acquired with protocol (1). The SNR of protocol (2) was reduced if the sagittal body diameter of the patient was greater than 20 cm and decreased significantly with diameters over 30 cm. By the use of protocol (3) the SNR was notably poor. The quality scored for the visualization of the entire aorta was 97.5% (protocol 1); 92.5% (protocol 2); and 80.0% (protocol 3).

CONCLUSION

In most cases the modified application of the body-phased array coil allows the imaging of the entire aorta as a single-shot 3D CE MRA in diagnostic quality.

Subarachnoid hemorrhage from vertebrobasilar dissecting aneurysm treated with staged bilateral vertebral artery occlusion: the importance of early follow-up angiography: technical case report

OBJECTIVE AND IMPORTANCE

Vertebrobasilar dissecting aneurysms are an uncommon but increasingly recognized cause of subarachnoid hemorrhage (SAH). We describe a patient with SAH caused by a dissecting aneurysm involving both vertebral arteries as well as the basilar trunk. The patient was treated successfully with proximal occlusion of the vertebral arteries using endovascular balloon occlusion in two stages. The importance of early follow-up angiography to document progression or resolution of untreated dissections is emphasized. This approach is suggested as definitive treatment for vertebrobasilar dissection in appropriate circumstances.

CLINICAL PRESENTATION

A 41-year-old man presented with SAH from spontaneous vertebrobasilar dissection. Angiography revealed aneurysmal dilation of the right vertebral artery and basilar trunk and occlusion of the left vertebral artery.

INTERVENTION

The dissecting aneurysm was treated with balloon occlusion of the right vertebral artery. Repeat angiography 2 weeks later demonstrated resolution of the left vertebral occlusion, with restoration of antegrade flow in the basilar trunk and increased filling of the right vertebral and basilar dissecting aneurysms. Balloon occlusion of the left vertebral artery led to aneurysm thrombosis and excellent clinical outcome.

CONCLUSION

Bilateral vertebrobasilar dissecting aneurysms are an uncommon cause of SAH. If unilateral proximal vertebral artery occlusion is chosen as the initial treatment, it is essential to document the status of the contralateral vessel using follow-up angiography. Staged bilateral vertebral artery occlusion should be considered in the event of recurrent or progressive aneurysm enlargement. Endovascular balloon occlusion has advantages over proximal clipping of the parent vessel: cranial nerve manipulation is avoided, test occlusion in the awake patient can be performed at the site of permanent occlusion, and therapeutic levels of anticoagulation can be maintained throughout and after the procedure, thus diminishing the likelihood of thromboembolic complications.