Twiglike middle cerebral arteries

Current state and confusion of twig-like middle cerebral artery

A twig-like middle cerebral artery (MCA) is an uncommon lesion in which a plexiform network of small vessels replaces the M1 segment of the MCA. Currently, we have insufficient information for twig-like MCAs. Therefore, a review of the literature using PubMed was conducted. In this review of twig-like MCAs, the following were discussed: the definition, pathogenesis, hemodynamics, associated aneurysm, clinical manifestations, imaging examinations, therapeutic strategies, therapeutic complications and prognosis. In addition, we proposed a reasonable grading system for twig-like MCAs, which is significant. For a twig-like MCA, the pathogenesis is unclear, and congenital and acquired factors can be involved. A twig-like MCA disturbed cerebral hemodynamics. An associated aneurysm can occur in patients with twig-like MCAs. Twig-like MCAs can present subclinically and without clinical symptoms, hemorrhage, or ischemic strokes. Of all the available imaging examinations, digital subtracted angiography is the gold standard. When treating a twig-like MCA, it is feasible to target the associated aneurysm, and extracranial-intracranial bypass can be effective in reducing the risk of strokes, but more evidence is needed. Now, the decision to perform surgery for twig-like MCAs should be made on a case-by-case basis.

Twig-like Middle Cerebral Artery: Case Series in a European Population

OBJECTIVES

Twig-like middle cerebral artery (MCA) is a rare anomaly where the M1 MCA is partially or completely replaced by a plexiform network. It has been described in angiographic series from Asian and South-American cohorts, but has not yet been reported in a European population.

METHODS

The digital subtraction angiograms (DSAs) of adult patients referred to a single neurovascular center for a diagnostic hypothesis of moyamoya arteriopathy (MMA) from 2018 to 2023 were prospectively and retrospectively checked by experienced neuroradiologists for identifying patients with twig-like MCA. The angioarchitecture of twig-like MCA was systematically evaluated and described.

RESULTS

Five of 30 (16.7%) male patients (mean age 55.8 + 14.7 years) of European ancestry were identified as having twig-like MCA. The clinical presentations were ischemic stroke (2 of 5), hemorrhagic stroke (1 of 5), and headache (2 of 5). All patients showed a unilateral involvement on DSA and in 1 of 5 (20%) an intracranial aneurysm was found. DSA was used to confirm the diagnosis of twig-like MCA and define the angioarchitecture and associated anomalies. An accessory MCA and recurrent artery of Heubner were found in 3 of 5 (60%) cases, feeding the network together with the anterior choroidal artery (4 of 5, 80%).

CONCLUSIONS

Twig-like MCA is a rare vascular anomaly, but it seems to be less rare than expected among adult European patients with suspected MMA on noninvasive neuroimaging studies. DSA is fundamental for a reliable differential diagnosis and should not be omitted in these patients.

Contralateral approach for the treatment of a distal supraclinoid aneurysm: a technical case report

Background: When treating intracranial aneurysms with open microsurgery, rare cases arise in which an ipsilateral approach leads to poor visualization, lack of proximal control, or potential damage to nearby vital structures due to the anatomy of the aneurysm. Case Description: We describe a patient with a small, unruptured aneurysm arising from the medial aspect of the distal supraclinoid internal carotid artery (ICA), just below the ICA bifurcation. A contralateral surgical approach was chosen because our view of the aneurysm from an ipsilateral approach would have been obstructed by the ICA. The contralateral approach provided excellent exposure of the aneurysm and allowed for precise clip placement without complications. Conclusions: Contralateral approaches may be a good option for some small medially pointing aneurysm of large proximal cerebral arteries.

Variations in the Anatomy of the Willis' circle: A 3-year cross-sectional study from Iran (2006-2009). Are the distributions of variations of circle of Willis different in different populations? Result of an anatomical study and review of literature

Background:

It is not well known whether the distributions of variations of circle of Willis (CW) are different in different populations. Previous studies have indicated: (a) The variations of the structure of the CW in different populations and ethnic and (b) some correlation between those congenital anatomical variations and possible cerebrovascular diseases. The frequency of such anatomical variations has not been evaluated sufficiently in the Iranian population. The aim of this study is to find the variations of the anatomy of the vessels in the CW in sample population of Iranian people and compare it with other available studies in the literature, providing a new grouping for variations.

Methods:

Samples were obtained from 200 autopsies in different ages, all retrieved in the department of Forensic Medicine, Tehran university of Medical Sciences after achieving permission from the Department of Ethics and Medico-legal Sciences. The CW was examined directly, using magnification, at the base of the brain. The cerebral vessels were observed for their configuration and their calibers were measured directly. Variations were noted and grouped into different categories.

Results:

Out of the 200 specimens examined, 69 (34.5%) were compatible with the typical anatomy of the CW. In the remaining 65.5% of the specimens, there were variations in the CW. Hypoplasia of the posterior communicating arteries was the most common variation in our study. One of the autopsies showed the presence of an aneurysm (0.5%).

Conclusion:

The anatomical variations found in our study were not significantly different from those reported in the literature. Based on the available data; (a) there is no evidence that the distribution of the variations of the anatomy of the CW is different in various societies and (b) the prevalence of the congenital aneurysmal changes in this region is not low in the Iranian population.