An MRI study of typical anatomical variants of the anterior communicating artery complex

Abstract Purpose The spring ligament complex (SL) is the chief static stabilizer of the medial longitudinal foot arch. The occurrence of normal anatomical variants may influence radiological diagnostics and surgical treatment. The aim of this study was to evaluate anatomical variants of the part of SL located inferior to the talar head (i-SL), medioplantar oblique ligament (MPO) and inferoplantar longitudinal ligament (IPL). Methods We included 220 MRI examinations of the ankle performed on a 3.0 T engine. Only patients with a normal SL were included. Two musculoskeletal radiologists assessed the examinations and Cohen’s kappa was used to assess agreement. Differences between groups were assessed using the chi-squared test; p < 0.05 was considered as significant. The final decision was made by consensus. Results Most commonly, i-SL was composed of the two ligaments IPL and MPO n = 167 (75.9%); in this group, bifid ligaments occurred in 19.2%, most commonly in the MPO. A branch to the os cuboideum was seen in n = 17 (10.2%). Three ligaments were seen in n = 52 (23.6%). In this group, bifid ligaments occurred in 13.5%; most commonly, the IPL was bifid and a branch to the os cuboideum was noted in n = 6 (11.5%). In one case, n = 1 (0.04%), we identified MPO, IPL and two accessory ligaments. No significant relationship was noted between the number of ligaments, the presence of bifid ligaments and side or gender (p > 0.05). Conclusion. More than two aligaments were seen in 24.1% of examined cases, the most common variant was the presence of MPO, IPL and one accessory ligament.

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Paraplegia Due to Rupture of an Anterior Communicating Artery Aneurysm

Interventional Neuroradiology ◽

10.1177/159101999600200107 ◽

1996 ◽

Vol 2 (1) ◽

pp. 53-57

Author(s):

T. Kombos ◽

H.-J. Meisel ◽

C. Janz ◽

M. Brock

Keyword(s):

Cerebral Angiography ◽

Artery Aneurysm ◽

Anterior Communicating Artery ◽

Anatomical Variants ◽

Anterior Communicating Artery Aneurysm ◽

Spinal Lesion

A 44-year-old patient developed paraplegia following rupture of an anterior communicating artery aneurysm. There was no evidence of any spinal lesion. Cerebral angiography showed a paired bihemispheric disposition of the A2 segment. We report this case and consider the anatomical variants of the A2 segment described in literature. The paired bihemispheric variant was reported in 21% of the cases. An azygos (unpaired) artery was observed in 5% and a triplicated A2 segment in 20% of the cases.

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Carotid siphon geometry and variants of the circle of Willis in the origin of carotid aneurysms

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2012001200003 ◽

2012 ◽

Vol 70 (12) ◽

pp. 917-921 ◽

Cited By ~ 10

Author(s):

Ângelo Raimundo Silva Neto ◽

Ródio Luis Brandão Câmara ◽

Marcelo Moraes Valença

Keyword(s):

Retrospective Analysis ◽

Circle Of Willis ◽

Posterior Communicating Artery ◽

Control Group ◽

Anterior Communicating Artery ◽

Anatomical Variants ◽

Carotid Siphon ◽

Hemodynamic Stress ◽

Carotid Aneurysms

This study evaluated anatomical variants in the carotid siphon and of the circle of Willis in patients with aneurysms. We performed a retrospective analysis of cerebral angiographies. The Control Group was composed of patients without aneurysms. Posterior communicating artery (PcomA) aneurysms were more common in women (p<0.05), and the anterior communicating artery (AcomA) aneurysms in men (p<0.1). The incidence of fetal-type PcomA was higher in cases with co-occurring PcomA aneurysm (24 versus 8%, p<0.05). Patients with AcomA aneurysm had higher incidence of A1 hypoplasia (p<0.0001, OR=32.13, 95%CI 12.95-79.71) and lower frequency of fetal-type PcomA compared to their control counterparts (p=0.0125). The angle of carotid siphon was narrower in patients with PcomA aneurysm (27.3±19.1 versus 34.8±22.6, p=0.028). In conclusion, a narrower carotid siphon or the presence of fetal-type PcomA or A1 hypoplasia may cause hemodynamic stress, thereby promoting the formation of aneurysms in susceptible individuals.

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Abstract 1122‐000184: Cerebral Arterial Variations in Patients with Ischemic Stroke Undergoing Mechanical Thrombectomy

Stroke: Vascular and Interventional Neurology ◽

10.1161/svin.01.suppl_1.000184 ◽

2021 ◽

Vol 1 (S1) ◽

Author(s):

Bernard Solewski ◽

Karolina Brzegowy ◽

Paweł Brzegowy ◽

Agata Musiał ◽

Tadeusz Popiela ◽

...

Keyword(s):

Ischemic Stroke ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Mechanical Thrombectomy ◽

Anterior Communicating Artery ◽

Adult Type ◽

Anterior Portion ◽

Posterior Portion ◽

Anatomical Variants ◽

Retrospective Assessment

Introduction : This study aimed to determine what anatomical variants of the Circle of Willis (CoW) and the middle cerebral artery(MCA) are observed in patients with acute M1 occlusion and whether their prevalence differs from that described as “normal” in anatomy textbooks. Methods : We have performed a retrospective assessment of radiological examinations of patients with stroke due to middle cerebral artery M1 segment occlusion. All patients underwent mechanical thrombectomy from January 2015 until March 2021. The anatomy of the CoW was assessed on initial CT‐angiography and DSA. Branches of the MCA were observed on control DSA after recanalization. Results : A total of 100 patients were included in the analysis (58 females and 42 males, mean age: 71.6 +/‐ 13.9). Fully complete CoW was observed in 19% of patients. A total of 10% of patients had an incomplete anterior portion of CoW. In the incomplete anterior portion subgroup, the most common variation was the absence of anterior communicating artery (6% of total hemispheres), followed by the absence of one A1 (3% of total hemispheres). An incomplete posterior portion of CoW was identified in 79% of the patients. The absence of posterior communicating artery (PCoA) was observed in 59 patients. Sixteen patients had adult‐type PCoA, 3 patients had transitional‐type PCoA and 21 patients had fetal‐type posterior cerebral artery (PCA). In the subgroup of patients with fetal‐type posterior circle, 5 patients had no P1 segment of PCA. Anterior temporal branch of MCA was observed in 45% of the patients. Middle cerebral artery bifurcation was found in 80% of hemispheres, and trifurcation in 20%. In the bifurcation subgroup, 26% of MCAs had a dominating upper branch and 18% had a dominating lower branch. A duplicate MCA was observed in one hemisphere. Conclusions : In comparison to normal anatomy described in anatomy textbooks, the population of patients suffering from ischemic stroke due to M1 occlusion had a lower proportion of complete and closed CoW. A foetal type PCoA was observed to be prevalent (21%) in patients suffering from acute M1 occlusion. Detailed anatomical knowledge of anatomical variants of CoW in patients undergoing mechanical thrombectomy is essential for clinicians performing intravascular interventions and may aid procedure planning.

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