Anat Cell Biol.  2024 Dec;57(4):481-497. 10.5115/acb.24.005.

Morphology and variations of middle cerebral artery: systematic review and meta-analysis

• Sharma U
• Verma S
• Adithan S
• Khobragade A

• KMID: 2562495
• DOI: http://doi.org/10.5115/acb.24.005

Abstract

To review morphometry, morphology, branching patterns and anomalies of middle cerebral artery (MCA). The databases of PubMed, Google Scholar and Scopus were searched with different keywords. The review comprised of 45 studies. Meta-analysis was done for dimensions of MCA, shapes, patterns and MCA anomalies. Newcastle-Ottawa Scale was used for assessment of literature. Statistical analysis was done using R software using meta package. Thirteen research were combined to determine the proportion of MCA length and pooled proportion was 16.53 cm (15.33 to 17.72 cm); I² =98%; P-value<0.01. Nine studies were combined to determine proportion of MCA diameter and pooled proportion was 2.85 cm (2.52 to 3.17 cm); I² =100%; P-value<0.05. M1 segment mean length is more on left side as compared to right side. Mean length in males (16.57±1.40 cm) is more than females (15.9±1.32 cm). Mean diameter of M1 segment is similar on both sides. Mean diameter in males (3.20±0.09 cm) is higher than females (3.14±0.18 cm). Different branching patterns observed were single trunk, early bifurcation, bifurcation, trifurcation, quadrifurcation and multiple trunks. The most typical MCA branching pattern is bifurcation. The shapes of MCA like straight shaped, U shaped, C shaped, inverted U shaped and S-shaped of M1 segment have been described. Straight MCA is the most common shape. The MCA measurements and branching pattern will assist surgeons in limiting errors in the treatment of cerebral aneurysms and infarcts and providing the best possible result for the patients. An understanding of MCA shape will aid surgeons and physicians in effective endovascular recanalization.

Keyword

Middle cerebral artery; Cerebral angiography; Aneurysm; Embryology; Histology

Figure

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  Fig. 1 Flow chart showing methodology in detail according to PRISMA guidelines.

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  Fig. 2 Incidence of shapes of middle cerebral artery in various studies.

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  Fig. 3 Forest plot showing the metaanalysis of length (A) and diameter (B) of middle cerebral artery (MCA). CI, confidence interval. MRAW, mean raw.

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  Fig. 4 Funnel plot of the studies included in the calculation of the pooled length and diameter of the middle cerebral artery (MCA).

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  Fig. 5 Branching patterns and anomalies of middle cerebral artery (MCA). (A) Single trunk MCA (0.2% to 20.6%): main trunk (blue arrow) continues without dividing into trunks. (B) Early bifurcation of MCA (0.5% to 24%): main trunk bifurcates (blue arrow) at a distance of ≤5 mm from origin. (C) Bifurcation (blue arrow) of MCA into upper and lower trunks (48% to 98%). (D) Trifurcation (blue arrow) of MCA into upper, middle and lower trunks (1% to 29%). (E) Quadrifurcation (blue arrow) of MCA into four branches (0.7% to 3.8%). (F) Duplication of MCA (0.5% to 2.9%)-duplicated vessel (blue arrow) originates from internal carotid artery (ICA) and runs parallel to the main trunk of MCA. (G) Accessory MCA (0.1% to 2.7%)-it originates from anterior cerebral artery (ACA) and runs parallel to main trunk of MCA (blue arrow). (H) Fenestration of MCA (0.1% to 3%)-division of artery into 2 lumens (blue arrow) that unite distally.

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  Fig. 6 Showing schematic presentation of development of middle cerebral artery (MCA). (A) Internal carotid artery (1) branches to form a cranial division (2) and caudal division at 4–5 mm stage (3). (B) Primitive anterior choroidal artery (4) arises from cranial division at a stage of 7–12 mm and cranial division continues as anterior cerebral artery (5). (C) Arterial twigs (7) appear distal to anterior choroidal artery (6) at a stage of 12–14 mm. (D) Caudal division continuing as posterior communicating artery (9); cranial division continuing as primitive olfactory artery (10); development of plexiform network from arterial twigs (8). (E) Disappearing plexiform network (11); development of MCA from plexiform network (12); development of medial olfactory artery from primitive olfactory artery (13); branch of primitive olfactory artery supplying nasal fossa (14); recurrent artery of Heubner arising from primitive olfactory artery (15). (F) MCA becoming prominent after regression of plexiform network at a stage of 16–18 mm (16); and (G) at 40 mm stage MCA acquires adult configuration (17).

Reference

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