Occluded middle cerebral artery vascular stump mimicking aneurysm: case report and review of literature

A Systematic Review and Case Illustrations of Misdiagnosing Intracranial Aneurysms

Modern neuroimaging methods do not completely rule out false diagnoses of intracranial aneurysms which can lead to an unwarranted operation associated with risks of complications. However, surgical interventions for falsely diagnosed aneurysms are quite rare. The purpose of this study is to demonstrate two clinical cases of false-positive aneurysms and a systematic review of the literature dedicated to the incidence and etiology of false-positive aneurysms, identifying risk factors associated with false-positive aneurysms. A literature search in two databases (PubMed and Web of Science) using keywords "mimicking an intracranial aneurysm", "presenting as an intracranial aneurysm", "false positive intracranial aneurysms", and "neurosurgery" was conducted. A total of 243 papers were found in the initial search in two databases. Sixteen papers (including 20 patients) were included in the final analysis. There were 10 women and 10 men. The most common location of false-positive aneurysms was the bifurcation of the middle cerebral artery (MCA). In the posterior circulation, false-positive aneurysms were identified either on the basilar artery, or at the vertebro-basilar junction. The main causes of false intracranial aneurysm diagnosis included artery occlusion with vascular stump formation, infundibular widening, fenestration, arterial dissection, contrast extravasation, and venous varix. In conclusion, summarizing the results of our analysis, we can say that surgical interventions for false-positive aneurysms are an underestimated problem in vascular neurosurgery. Despite extremely rare published clinical observations, the actual frequency of erroneous surgical interventions for false-positive aneurysms is unknown.

False positive angiographic aneurysm of the anterior segment of the M1 bifurcation of the middle cerebral artery: a case report

Occlusion of an intracranial arterial branch, resulting in a false positive aneurysm on vascular imaging, is extremely rare, with only a few reports in the literature and mostly in the posterior circulation artery or the middle cerebral artery (MCA) bifurcation. We report a case of a 69 years-old woman with a subacute infarct lesion in the left frontal lobe, for whom both computed tomographic angiography (CTA) and digital subtraction angiography (DSA) of the cerebral vessels showed aneurysms in the anterior segment of the M1 bifurcation of the middle cerebral artery (MCA) and in the bifurcation of the MCA. The aneurysm in the MCA bifurcation was found during craniotomy, whereas the anterior segment of the M1 bifurcation had intact branch vessels with severe atherosclerosis and no aneurysm was present. The branch vessel of M1 was presumed to be atherosclerotic occlusion resulting in the distal vessels without contrast filling on CTA and DSA, and only the occluded stump at the beginning of the vessel was filled with contrast, showing an aneurysm-like morphology, which was very confusing. This case highlights to neurologists that the diagnosis of aneurysm by cerebrovascular CTA or DSA must be carefully differentiated to avoid misdiagnosis, especially if the unruptured aneurysm is in an uncommon location in combination with ischemic cerebrovascular disease.

Comparative study on the clinical outcomes and prognosis of endovascular embolization and craniotomy clipping for the treatment of cerebral aneurysms

Objective

To investigate the safety and outcomes of endovascular embolization and craniotomy clipping in the treatment of cerebral aneurysms.

Methods

We collected the clinical data of 106 patients with cerebral aneurysm who underwent surgical treatment (endovascular embolization, Group-A, n=55; craniotomy clipping, Group-B, n=51) in the First People's Hospital of Yichang from January 2020 to May 2021. We compared surgical treatment indexes, treatment costs, neurological function before and after the treatment, incidence of postoperative complications and the prognosis after one-year follow-up between the two groups.

Results

Endovascular embolization (Group-A) was associated with a shorter mean operation time and hospital stay, a lower mean intraoperative bleeding amount, and a higher mean treatment cost than craniotomy clipping (Group-B) (P<0.05). Compared with the pre-operative neurological function scores, the scores of both groups decreased after the surgery, and the mean post-operative score of Group-A was significantly lower than that of Group-B (P<0.05). Compared with Group-B , patients in Group-A had a lower overall complication rate (P < 0.05. Higher proportion of patients in Group-A had a good prognosis (P < 0.05).

Conclusion

Endovascular embolization for the treatment of cerebral aneurysms is safe as it can shorten the operation time and hospital stay, reduce the incidence of neurological injury and complications, and have a favorable prognosis. However, the treatment is more expensive. Endovascular embolization can be selected for the treatment of cerebral aneurysms when economic conditions allow it.

Republished: MRI SPACE sequence confirmation of occluded MCA M2 dissection stump masquerading as a ruptured MCA aneurysm

Intracranial vascular pathologies often have overlapping clinical presentations. Dissected vessel occlusions and bifurcation aneurysms can appear similar on pretherapeutic imaging. The medical management of these two entities is drastically different. The patient is a 51-year-old man who presented with severe, sudden-onset headache. Initial presentation was consistent with a ruptured middle cerebral artery (MCA) aneurysm and surgical clipping was recommended. However, further review of radiographic findings could not definitively differentiate an aneurysmal origin of the symptoms as opposed to intracranial dissection followed by occlusion of the M2 branch of the MCA. MRI sampling perfection with application optimised contrasts using different flip angle evolution (SPACE) was performed and showed thin flow signalling distal to the dissected vessel stump confirming the diagnosis. Accurate diagnosis is a crucial step in directing treatment for intracranial vascular lesions. MRI SPACE is a simple tool in the diagnostic armamentarium to adequately direct treatment and avoid the potential for unnecessary interventions.

MRI SPACE sequence confirmation of occluded MCA M2 dissection stump masquerading as a ruptured MCA aneurysm

Intracranial vascular pathologies often have overlapping clinical presentations. Dissected vessel occlusions and bifurcation aneurysms can appear similar on pretherapeutic imaging. The medical management of these two entities is drastically different. The patient is a 51-year-old man who presented with severe, sudden-onset headache. Initial presentation was consistent with a ruptured middle cerebral artery (MCA) aneurysm and surgical clipping was recommended. However, further review of radiographic findings could not definitively differentiate an aneurysmal origin of the symptoms as opposed to intracranial dissection followed by occlusion of the M2 branch of the MCA. MRI sampling perfection with application optimised contrasts using different flip angle evolution (SPACE) was performed and showed thin flow signalling distal to the dissected vessel stump confirming the diagnosis. Accurate diagnosis is a crucial step in directing treatment for intracranial vascular lesions. MRI SPACE is a simple tool in the diagnostic armamentarium to adequately direct treatment and avoid the potential for unnecessary interventions.

Evolution of a Stump Aneurysm That Transformed From a Fusiform Aneurysm in the Middle Cerebral Artery

BACKGROUND

A spontaneous fusiform aneurysm in the middle cerebral artery (MCA) can present with both ischemic and hemorrhagic symptoms, but this aneurysm's clinical course and prognosis are unclear because of its rarity.

CASE DESCRIPTION

An asymptomatic fusiform-shaped aneurysm was found in a branch of the right middle cerebral artery (MCA) incidentally during a medical check-up in a 51-year-old woman with no medical history. This aneurysm was followed by annual magnetic resonance imaging with no medical treatment. A distal side of the branch of the MCA harboring the fusiform aneurysm gradually narrowed, and finally occluded 6 years after initial detection. The stump of the branch transformed into an aneurysmal dilatation, which grew for 2 years. To prevent future subarachnoid hemorrhage, surgical intervention was performed. An aneurysmal dilation with a thin wall was found to originate between an intact branch and a funicular occluded branch, which was obliterated with clip application. At 3-year follow-up, no regrowth or de novo aneurysm could be seen.

CONCLUSION

This is the first case report in which serial images demonstrate the stepwise occlusion of an artery with fusiform change and the evolution of a stump aneurysm in the MCA over an extended period.