STENOSIS

CALCULATION OF THE STENOSIS DEGREE (%)

Diameter : 

ECST : C - A    X 100

                C

NASCET : B - A     X 100

                    B

Surface : 

(total surface - stenosis surface) /  total surface  x 100

-Stenosis degrees of severity: narrow 70-99%, intermediate 29-69%, light 0-30%.

-Extent of severity of the stenosis -Presence of ulceration -Associated lesions: contralateral carotid, vertebral as well as intracranial arteries.

European Method: ECST (European Carotid Surgery Trialist's Collaborative Group)

measurement of the diameter of the minimum circulating channel, reported to the diameter of the carotid bulb

defect: in arteriography, the external limit of the bulb is not visualized

North American Method: NASCET: (North American Symptomatic Carotid Endarteriectomy Collaborators Trial) or ACAS

measurement of the diameter of the minimum circulating channel, relative to that of the underlying normal internal carotid.

defect: the plate is not taken into account

Table of equivalence of the percentages of stenoses

A similar number of stenoses measured by the American method are less tight than those of the European method.

The larger the bulb, the larger the difference between the two methods

ECST     NASCET

50           20

70           50

75           60

80          70

which patients should be operated or having an angioplasty?

patients with tight stenosis (> 70%), whether asymptomatic or symptomatic (TIA, stroke with minor sequelae).

The benefit of Carotid Surgery has been clearly affirmed by several major European and American studies.

It reduces the risk of stroke by 80% for symptomatic narrowing and by 50% for asymptomatic lesions.

The surgical team must be specialized in vascular surgery, and have a low mortality-morbidity rate (<3% for asymptomatic stenosis, and <6% for symptomatic stenosis).