Bifurcation Lesion is a coronary artery narrowing occurring adjacent to, and/or involving, the origin of a significant side branch that you do not want to lose.
In simple terms, it is a lesion in parent vessel very close or involving a significant side branch.
Drug-eluting stents (DES) should be used for the treatment of bifurcation lesions, as treatment with bare metal stents (BMS) ha yield sub-optimal results.