Commentary: Multilayer Stent for the Treatment of Complex Aortic Pathologies: A Long or Short Road Ahead?

Abstract

‘‘Hic Sunt Leones’’ (here there are lions) was written on uncharted territories of old Roman maps; this notice alerted people leaving for a journey about the unknown and dangerous paths ahead. In this issue of the JEVT, two articles illustrated well that similar dangers awaited overenthusiastic interventionists who took the unexplored route to indiscriminate use of the Multilayer Flow Modulator (MFM) for compassionate or selected cases. The results were an assortment of data reporting negative and positive anecdotal experiences without any statistical power. Moreover, the early negative results alarmed the medical communities, which jeopardized their interest in this clinically untested but fascinating and innovative technology. The review of failed MFM cases by Sultan and colleagues and the sound clinical data from the structured STRATO trial contribute to our understanding of the indications for use (IFU) of the MFM. First off, let’s look at the question that is on everyone’s mind: do these endoprostheses live up to expectations in complex aortic pathologies? The answer: not completely. Treatment of thoracic and thoracoabdominal aortic aneurysms is attended by relatively high risk whether the procedure be surgical or endovascular, and the avoidance of rupture is at the core of these therapies. Chimney and fenestrated techniques (ChEVAR, F-EVAR) help to reduce mortality and morbidity, but they have precise IFUs and require well developed catheter skills. In ChEVAR, the maximum number of target vessels that can be safely stented has never been systematically studied, but two chimneys seems to be the number for a safe procedure. F-EVAR reports describe a 15% rate of secondary interventions within the first year. In this group, reintervention for endoleak accounted for 48% of cases; in the remaining 52%, a significant number of new surgical procedures were needed for mesenteric ischemia. Recently, Manning et al. reported their experience in F-EVAR using triple fenestration stent-grafting, underlining that, at present, these procedures are technically more demanding and associated with higher risks compared with double or single fenestrations. New technologies and increasing understanding of the pathophysiological mechanisms of vascular disease complement each other. A disease manifesting as an anatomical abnormality results from an interaction of molecular, biological, and biochemical processes. Novel, and somewhat unconventional, concepts of treating vascular pathologies rely on modulation of such processes through