|
Coronary bifurcation2,89
|
A coronary region consisting of 3 major parts: 1) PMV; 2) DMV (both together forming the MV); and the 3) SB.2 The longest and largest distal branch should be designated the DMV given the linear relationship between diameter, length, flow, and supplied myocardial mass.90 Bifurcation carina is the tissue connecting DMV and SB.
Within the bifurcation, we define the POB and the POC (Figure 3).91
POB is the center of the largest circle that fits in the bifurcation and touches all 3 contours. The POB is the point where all 3 centerlines (ie, the lines through the middle of the vessel) from the PMV, DMV, and side branch meet (Figure 3).
POC represents the smallest possible independent region that behaves differently from a single vessel segment. It is defined on the 2D radiographic image as the area or region that encompasses the start and the end of the bifurcation region. The intersections of the largest circle, touching all 3 contours of the bifurcation, with the centerlines of each vessel indicate the boundaries of the POC (Figure 3).
Considering the limitation of 2D angiography, such entities should be identified in the optimal angiographic view for a given bifurcation, which requires no overlap of distal branches, minimal foreshortening, and displaying of the widest bifurcation angle.
|
|
Bifurcation lesion2
|
Angiographically, a bifurcation lesion is defined as a coronary stenosis adjacent to and/or involving an adequate-sized SB (≥2.0 mm in RefD).6 The lesion is considered significant when its %DS is >50 and the MLD in at least 1 of the 3 segments is located ≤4 mm from the POB.6,89
|
|
Relevant side branch92
|
Relevance, according to the proposed algorithm (Figure 5), to be considered only if RefD ≥2.0 mm.
|
|
Coronary trifurcation93
|
Anatomically, we define a trifurcation as a division of an MV into 3 branches, each of which has a lumen diameter ≥2.0 mm. The DMV is defined as the longest and the largest branch, likely reflecting the largest perfusion territory. Between the SBs, the one with the larger diameter is defined as SB1, while the other is SB2.93
|
|
Trifurcation lesion93
|
Trifurcation lesions are defined by a %DS ≥50 within 4 mm from the POB involving either the MV (proximal and/or distal), with or without significant disease in either 1 or both SBs.
|
|
%DS: percentage diameter stenosis; DMV: distal main vessel; MLD: minimum lumen diameter; MV: main vessel; PMV: proximal main vessel; POB: point of bifurcation; POC: polygon of confluence; RefD: reference diameter; SB: side branch.
|
