Internal Trapping of a Growing Ruptured Dissecting Aneurysm of the A1 Segment: A Case Report and Literature Review

A 47-year-old man presented with sudden-onset headache and Fisher group 3 subarachnoid hemorrhage. The World Federation of Neurological Surgeons grade was II. Digital subtraction angiography (DSA) only showed a vessel wall irregularity in the A1 segment of the right anterior cerebral artery (ACA), but an obvious bleeding source was not detected. Repeat angiography showed a tiny aneurysmal dilatation in the A1 segment with an intimal flap. The aneurysm enlarged on subsequent angiograms. Dissecting aneurysm was diagnosed, and the patient underwent internal trapping of the A1 segment to prevent rerupture. Postoperative DSA showed complete obliteration of the dissected segment. Magnetic resonance imaging showed a clinically silent cerebral infarction in the territory of the A1 segment perforators. Parent vessel occlusion for a dissected A1 segment can be effective, provided that sufficient collateral blood flow from the contralateral ACA is observed. We recommend endovascular trapping in this setting and hope that fellow clinicians select this approach for this rare pathology.

A Case of Internal Carotid Artery Dissection with Ischemic Onset, Followed by Subarachnoid Hemorrhage during Diagnostic Angiography

Objective

Internal carotid artery (ICA) dissection is known to cause binary types of stroke, cerebral infarction, and subarachnoid hemorrhage (SAH). However, it is rare that these two pathologies take place in a clinical scenario. We report a case of ICA dissection with ischemic onset, which was followed by SAH on the same day during diagnostic angiography.

Case Presentation

A 60-year-old woman with chronic hypertension rapidly developed right hemiplegia. She had been suffering from slight headache and abnormal sensation in the right limbs 1 week before the ictus. MRI demonstrated small acute infarctions in the left middle cerebral artery (MCA) territory. The left ICA was not visualized on MRA. Diffusion-perfusion mismatch was indicated by the automated image postprocessing system. Endovascular recanalization was planned to prevent the progression of cerebral infarction. After advancing a 5MAX ACE, initial left ICA angiography was performed, resulting in extravasation of contrast medium from the C2 segment of the left ICA. 3D rotational angiography revealed left ICA dissection of the C2 segment. To secure hemostasis, the patient underwent internal trapping at the C1 and C2 segments of the left ICA. Collateral flow to the left MCA via an anterior communicating artery was observed. On day 28, the patient was transferred to a rehabilitation hospital with right hemiplegia and motor aphasia.

Conclusion

In cases of tandem lesions with preceding neurological symptoms, ICA dissection should be considered as one of the causes. Careful injection of contrast medium may be necessary if ICA dissection is strongly suspected.

Surgical Management of Intracranial Artery Dissection

Intracranial artery dissection (IAD) is a relatively rare cause of stroke, but it has been recognized increasingly with recent advances of the neuroimaging technique. Since rebleeding occurs frequently in the acute stage in the ruptured IAD, urgent surgical treatment should be performed to prevent rebleeding. On the other hand, surgical treatment for unruptured IAD is controversial because it has little risk for bleeding. However, surgical treatment for unruptured IAD may be considered if the formation or enlargement of the aneurysmal dilatation has been confirmed. Since there are several proposed surgical strategies for IAD, it is important to select an appropriate strategy on a case-by-case basis. If the risk of infarction due to vessel occlusion is high, combined bypass surgery should be considered.

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.

Serial angiography and endovascular treatment of dissecting aneurysms of the anterior cerebral and vertebral arteries. Case report

This 47-year-old man was admitted to the hospital with disturbance of consciousness due to subarachnoid hemorrhage caused by a ruptured dissecting aneurysm of the left anterior cerebral artery (ACA). Conservative treatment resulted in improvement in the patient's consciousness; however, repeated rupture occurred during the chronic stage. Endovascular coil embolization of the parent artery was successful. Serial angiography demonstrated all stages in the development of the aneurysm. Follow-up angiography demonstrated an incidental dissecting aneurysm of the right vertebral artery. This aneurysm was also treated by endovascular embolization. No new neurological deficit appeared during or after the treatment. Multiple dissecting aneurysms are rare, especially those involving both supra- and infratentorial regions. A ruptured dissecting aneurysm of the ACA is also an uncommon vascular disorder. This case shows that rebleeding may occur, even during the chronic stage, and thus appropriate treatment for the prevention of subsequent bleeding is essential. Incidental dissecting aneurysms can be treated using the endovascular technique, but further study is necessary.