Addressing coronary bifurcation lesions

Bifurcation lesions have wide range of variations in plaque burden, plaque location, site of the bifurcation, angle between the branches and diameter of the branches. Factors during treatment like plaque shift and dissection are also different with each lesion. The true bifurcation lesions are those belonging to the Medina classes 1.1.1, 1.0.1, and 0.1.1 where both the main branch and side branch are significantly narrowed.
A single stent strategy is the rule for all non-true bifurcation lesions. While treating true bifurcation lesions, consideration should be given to the extend of disease in the side branch – whether the lesion is limited to the ostium or involving the vessel beyond the ostium, size of the side branch, angle of take off and the territory of distribution of the side branch. Earlier it was thought that all true bifurcation lesions need a two sent approach. At present, about one third of true bifurcation lesions will need two stents, except in left main coronary artery bifurcations which may need two stents in half of the cases. Stenting of the side branch is favoured if the side branch is an important vessel or sometimes as important as the main branch. Dedicated bifurcation stents may be another option in development in the treatment of bifurcation lesions. While treating bifurcation lesions, both vessels have to be wired initially. The side branch wire is jailed during stenting of the main branch. This is useful in protecting the side branch from closure by a plaque shift. This wire facilitates the rewiring of the side branch if needed as it widens the angle between the side branch and the main branch. Rewiring is needed if post-dilation or stenting of the side branch is needed or if a final kissing balloon dilatation is needed. Final kissing inflation is needed if the side branch has been dilated through the struts of the main branch stent. This is to correct the distortion of the main branch stent which was produced by the side branch dilatation. The side branch wire also acts as a maker for the side branch ostium if the side branch gets occluded. Jailing of hydrophilic guide wires should be avoided as there is a chance of removal of the polymer coating while pulling back. Care should be taken to prevent too much entry of guide catheter into the coronary ostium while removing the jailed wire from the side branch. Two stent strategy is preferred when the side branch is large (higher territory of distribution) and when the lesion in the side branch extends beyond the ostium. With the provisional side branch stenting strategy, side branch stenting is needed if there is plaque shift with more than 75% stenosis of side branch or there is a flow limiting side branch dissection. T-stenting is preferred when the bifurcation angle is close to 90 degrees as it will provide complete coverage of the side branch ostium. If the angle is more acute, culotte or crush techniques are preferred. When a side branch is insignificant or diffusely diseased and not suitable for stenting, it is not rewired or post dilated, though the initial wiring may be done.

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