Description

An atherosclerotic plaque in a coronary artery may be classified based on the features seen on coronary angiography. The complexity of a lesions has implications for the degree of risk involved during angioplasty.


 

Types of lesions:

(A) minimally complex

(B) moderately complex

(C) severely complex

 

Parameter

Type A

Type B

Type C

length of lesion in mm

discrete ( < 10 mm)

10 – 20 mm

diffuse (> 20 mm)

plaque distribution

concentric

eccentric

 

angulation of segment

nonangulated (< 45°)

moderate (45 – 90°)

extreme (> 90°)

contour

smooth

irregular

 

calcification

none or little

moderate or heavy

 

occlusion

less than total

total occlusion < 3 months old

total occlusion > 3 months old or with bridging collaterals

location

not ostial

ostial

 

side branch involvement

none

able to protect

unable to protect major side branches

thrombus

absent

some

a lot

tortuosity of proximal segment

slight (readily accessible)

moderate

excessive

other

 

bifurcation lesions requiring double guide wires

degenerated vein grafts with friable lesions

 

where:

• The original table does not have an entry for thrombus under Type C.

• The original table does not have an entry for side branch involvement for Type B.

 


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