Carotid Endarterectomy for a Case with an Extremely Twisted Internal Carotid Artery

The internal carotid artery (ICA) typically runs posterolaterally to the external carotid artery (ECA) at the level of the common carotid artery (CCA) bifurcation in the neck. The "twisted ICA" is an anatomical variation, wherein the ICA is medial to the ECA. Several studies on the twisted ICA have discussed its anatomical definition, incidence, clinical features, and surgical results in patients with luminal stenosis. Computed tomography angiography (CTA)-based analyses of surgically treated cohorts documented a twist angle, reaching up to 95°. Carotid endarterectomy (CEA) was successfully performed for these patients. This study reports a case of a significantly twisted ICA with severe luminal stenosis that was successfully treated with CEA. An 81-year-old male was incidentally diagnosed with asymptomatic right ICA stenosis based on magnetic resonance (MR) angiography. Three-dimensional (3D)-CTA showed that the ICA revealed 74% stenosis of the ICA, based on the North American Symptomatic Carotid Endarterectomy Trial criteria. The 3D-CTA showed the ICA medial to the ipsilateral ECA at the level of the CCA bifurcation in the neck. It extended proximally to the pharynx, and the twist angle was 102°. Black-blood MR of the carotid plaque exhibited a high intensity on T1-weighted imaging, indicating vulnerability. Intraoperatively, the position of the ICA was corrected using multiple hooks instead of a surgical retractor. He showed no permanent deficits, such as an ipsilateral cerebral infarction, although transient postoperative hoarseness was observed. This case report documented a significantly twisted ICA with luminal stenosis, successfully treated via CEA, by correcting the carotid position using multiple hooks with gentle manipulation.