Insight into the periprocedural embolic events of internal carotid artery angioplasty. A report of four cases and literature review

Abstract

Thromboembolism is a major risk of carotid angioplasty and stenting (CAS). Although the incidence of distal embolism has been documented by MRI and TCD studies, the mechanisms and management of this complication are rarely reported. Here we describe four patients with periprocedural embolic events to demonstrate the mechanisms of thromboembolism in CAS. Different remedies were applied to these patients according to the underlying mechanisms of thromboembolism and good clinical outcomes were achieved.

Figure 1

DSA obtained from case 1. A) Severe stenosis (>90%) of the left ICA origin. B) Deployed with a 10×24mm stent (Wallstent, Boston) over the lesion. The immediate angiogram demonstrated nearly normal lumen of the stenotic segment. C) After retrieval of the protective device, we noted the occlusion of a frontal branch of the left MCA (arrow). D) After the embolus was pushed to a distal cortical artery with a microcatheter, blood to the paracentral branches was restored (arrow).

Figure 2

DSA obtained in case 2. A) The angiography demonstrated severe stenosis of both ICA origins, the left (A) is worse than the right. B) A stent (9×30 mm, Precise, Cordis) was deployed missing the upper part of plaque. After another balloon was inflated, the lumen turned to normal. C) Angiography taken one week after stenting demonstrated a thrombus just distal to the stent. D) A second stent (8×30 mm, Precise, Cordis) was deployed under distal embolic protection, and the lumen appeared normal.

Figure 3

DSA obtained in case 3. A) The pre-operative DSA demonstrated severe stenosis of the right ICA origin. B) The angiography obtained immediately after predilation showed near occlusion of ICA beyond the lesion and very slow blood flow. C) A stent (10×40 mm, Precise, Cordis) was deployed quickly and the stenotic artery was recanalized. D) The DWI after stenting presented multiple new ischemic lesions on right frontal and parietal white matter (arrows).

Figure 4

DSA obtained in case 4. A) Pre-operative DSA confirmed severe stenosis of the initial segment of right ICA and stagnant blood flow in the distal artery. B) After a self-expanding stent (10×40 mm, precise, Cordis) was deployed, the immediate angiogram showed the residual stenosis was less than 30%. C) DSA obtained 6 hours after stenting showed completely expanded stent without intraluminal filling defect. D) The CT scan obtained 24 hours after stenting showed a small new lesion in the right hemisphere (arrow).

Supplemental Figure 1

Case 4 explanation in the text.