Conservative management of left main dissection: Breaking the taboo

Left main (LM) dissection has always represented a feared, potentially catastrophic iatrogenic complication during percutaneous coronary intervention (PCI) and a “taboo” in discussions among interventionalists. It can lead to cardiac arrest, and it remains one of the few causes of acute coronary artery bypass grafting during coronary angiography or PCI. However, not all dissections are the same. Flowlimiting LM dissections constitute a cath lab emergency and should be promptly treated to establish adequate flow. Furthermore, antegrade LM dissections should be “covered” to prevent a possible subacute expansion of the dissection plane. In the past, conservative or percutaneous management of such dissections were unpredictable mainly because of the limited resolution provided by angiography [1,2]. In this case report, Binder et al. elegantly present a case of an iatrogenic retrograde dissection, induced by angioplasty balloon rupture extending to the LM. After stenting of the distal “entry point” and with the use of optical coherence tomography (OCT) technology, they accurately described a well concealed, nonflow limiting dissection. OCT technology provided confirmation that there were no additional uncovered entry points and accurate data about the length and size of the dissection plane. Stenting of such dissection may lead to shifting of the subintimal hematoma to the ascending aorta resulting in catastrophic long aortic dissections [3]. OCT has emerged from a research tool to an invaluable intravascular imaging modality with excellent resolution allowing superior visualization of the vessel wall. With its increasing use in the everyday practice, we encounter new information with unclear clinical significance. Binder et al. intelligently used the data provided by OCT to make a major clinical decision and conservatively treat a LM dissection, breaking a long-standing taboo. In a separate note, OCT use in ST elevation myocardial infarction patients has helped the identification of patients with plaque erosion in whom, following gentle predilation of the lesion with thrombectomy and establishment of reasonably good distal flow, stent implantation was avoided with a similar outcome as compared to patients with plaque rupture requiring stent implantation [4]. Although larger clinical trial are needed to correlate OCT findings with clinical outcomes, proper use of OCT in the today’s cath lab seems to contribute to the best clinical decision making. As we are all critical about the clinical application of OCT in the cath lab, we should also remember that intravascular ultrasound went through the same path in the past. Therefore, the more we learn about OCT findings and their clinical correlations, its role in our daily clinical practice will expand rather than remain an exciting research tool.