Carotid stenosis and carotid plaque analysis relevant to carotid endarterectomy and stent-assisted angioplasty
The primary objective of this cadaveric study was to review the morphological variations of the anatomy of the human carotid artery bifurcation relevant to carotid endarterectomy (CEA) and carotid artery stent-supported angioplasty (CSSA). We quantify carotid bifurcation plaque morphology. Results showed that the angle of deviation at the origin of the internal carotid artery (ICA), in relation to the common carotid artery (CCA), measured a mean of 21.8 degrees with a range from seven to 45 degrees. This anatomical finding is important for the interventionalist concerned with insertion of a carotid stent. The angle of the ICA origin may be an independent risk factor for early atherosclerotic changes at the ICA bulb. Carotid bifurcation plaque was observed in a small, random cohort of seven out of 13 cadavers, and contributed to a mean stenosis of 15.2% (range 5.0-34.8%). Plaque morphology (n = 7) showed haemorrhage (29%), superficial thrombosis (57%), calcification (71%), areas of focal necrosis (71%), neovascularisation (14%) and infiltrates (29%). Ulcerations were not detected. Although four out of 13 patients (31%) died of a cerebrovascular accident, the cause of cerebral apoplexy was thought not to be associated with the carotid bifurcation pathology. 'Re-boring' of occluding plaque, as in CEA, offers potential volumetric anatomical advantage over CSSA within the carotid bifurcation and bulb. In conclusion, precise and applied knowledge of carotid bifurcation anatomy is critical to reduce technical complications during CEA or CSSA. This information may reduce potential dangers of iatrogenic thrombo-embolism and ensuing neurologic deficits. Patients with low-grade carotid stenosis, evidence of focal plaque necrosis, are at risk of spontaneous plaque cap rupture, distal thrombo-embolism and stroke.