A unique temporary collateral pathway between carotid-vertebrobasilar arteries in a carotid dissection patient

Abstract

Background: In adults, the anastomosis between carotid and vertebrobasilar arteries is usually the posterior communicating artery, sometimes the primitive trigeminal artery. In this case, the basilar artery fed the internal carotid artery through the pontine-to-tentorial artery anastomosis after severe stenosis from traumatic carotid dissection.

Case presentation: A 32-year-old female was diagnosed with ischemic stroke caused by traumatic carotid artery dissection. Aspirin (100 mg/day) and clopidogrel (75 mg/day) were prescribed. Digital subtraction angiography performed 6 days after stroke onset showed a dissection in the cervical segment of left internal carotid artery with severe local stenosis, and a collateral pathway from BA to the cavernous segment of internal carotid artery through the lateral pontine and tentorial artery. Without interventional therapy, clinical symptoms improved significantly within 10 days after onset. At 3-month follow-up, left common carotid artery angiography showed the stenosis had been significantly improved with a residual aneurysm. There was no collateral pathway between carotid-vertebrobasilar arteries, and a residual small artery originated from the posterior vertical segment of cavernous internal carotid artery. The small artery was clearly visualized by 3-dimensional rotational angiography and identified the tentorial artery.

Conclusion: To the author's knowledge, this is the first report of a collateral pathway between carotid vertebrobasilar arteries through the pontine-to-tentorial artery anastomosis. Meanwhile, tentorial artery origination directly from the cavernous segment of internal carotid artery is rare and easily mistaken for persistent primitive trigeminal artery. 3-dimensional rotational angiography can provide sensitive and accurate diagnostic assessment of the small artery, and may be a useful tool for screening of abnormal small arteries.

Keywords: 3-dimensional rotational angiography; Collateral circulations; Internal carotid artery dissection; Ischemic stroke.

Fig. 1

Diffusion Weighted Imaging (a) and magnetic resonance angiography (b, c) at 24 h after stroke onset, Digital subtraction angiography at 6 days after stroke onset (d, e, f, g) and at 3 months after stroke onset (h, i). a Diffusion Weighted Imaging showed moderate-sized infarcts involving the left frontal-parietal cortex; b Anteroposterior image of magnetic resonance angiography; c Oblique image of magnetic resonance angiography; d Aortic arch angiogram; e Anteroposterior view of left common carotid artery angiography; f Anteroposterior view of right vertebral artery angiography; g Lateral view of right vertebral artery angiography; h Lateral view of left carotid angiography; i Lateral view of right vertebral artery angiography. 1: the left internal carotid artery; 2: the tentorial artery; 3: the aberrant right subclavian artery; 4: the right vertebral artery originated from the right common carotid artery; 5: the left vertebral artery originated from aortic arch; 6: the formation of carotid dissection; 7: the lateral pontine artery; 8: the posterior communicating artery; 9: the internal carotid artery aneurysm

Fig. 2

a Local enlargement of b) The 3-dimensional rotational angiography of left internal carotid artery 3 months after stroke onset. The post-processing image clearly showed the complete path of the tentorial artery. 1/Yellow line: left internal carotid artery, 2/Red line: the tentorial artery, 3/Green line: the left posterior communicating artery