Role of intravascular ultrasound in unprotected left main percutaneous coronary intervention.

Percutaneous coronary intervention (PCI) to the unprotected left main stem offers an attractive alternative to bypass grafting, but is associated with a significant clinical risk and therefore demands special consideration. Successful left main PCI is dependent upon the morphology of the lesion and the technical quality of the procedure. For these reasons, intravascular ultrasound (IVUS) has been the most popular adjunct to coronary angiography during left main PCI. However, trials of IVUS in left main PCI have produced inconclusive results, and most data predate the use of drug-eluting stents. Despite this, IVUS offers practical benefits in both case selection, and in guiding angioplasty and stenting. Here, we review the arguments for the present and future role of IVUS in left main PCI.