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The DRASTICO Trial: DEB vs DES for Complex Peripheral Intervention
Welcome to the February edition of Vascular Disease Management. There are many articles and interviews of great clinical importance in this issue. I have chosen to comment on Dr Liistro’s interview about his single-center DRASTICO trial, in which he is comparing drug-eluting balloon (DEB), utilizing the Impact Admiral balloon, and drug-eluting stent (DES), utilizing the Zilver PTX stent in treating the complex lesions faced by interventionists rather than the less complex disease subsets studied for device approval.
I have chosen this topic as there is great debate about which therapy should be utilized to treat symptomatic peripheral arterial disease. Those who believe that DEB should be the first-line therapy argue that the DEB treats the entire endothelial surface of the vessel rather than just the sites where the stent tines touch the endothelium. DEB pundits also argue that a DEB strategy avoids the need for a permanent implant, which may have long-term deleterious effect. DES advocates argue that DESs create a larger and more stable initial lumen by blocking the initial elastic recoil and by pinning dissections. DES pundits argue that this larger and more stable initial lumen is superior and should result in better long-term patency. Each of these devices exposes the arterial wall only to an initial bolus of paclitaxel, as the Zilver PTX stent has no polymer to afford continued release of antiproliferative drugs. The stents utilized in treating coronary artery disease, which have very low restenosis rates, all have polymers that facilitate more prolonged drug delivery in an effort to limit restenosis. It will be interesting to see the final results of this trial. I do not see where the use of intravascular ultrasound, which could more precisely measure the true initial luminal gain, is mandated in this trial. I am concerned that quantitative angiography alone may not effectively portray true initial luminal gain even if angulated views are taken. I’m not certain as to the strategy utilized in this trial where there are flow-limiting dissections (ie, are stents allowed?). This trial does not include the utilization of atherectomy to allow better vessel prep, particularly in the DEB group. Despite these limitations, this trial may provide some guidance to interventionists about how we should approach complex femoral and popliteal arterial occlusive disease. It may take years of follow-up to determine not just primary patency, but secondary and tertiary patency. Symptomatic relief and limb salvage rates must be assessed long term. Overall treatment costs must also be delineated initially and over the short-term and long-term follow-up periods. I strongly suspect that by the time this study has been completed, there will be Food and Drug Administration (FDA)-approved DEBs that are substantially different than presently available DEBs as well as new DES platforms that may have different stent properties and sustained drug-delivery capabilities. Arguments as to whether these devices could possibly tilt the outcomes in either direction will continue. Despite these limitations, I believe that this is an important first-step trial that will help to guide future therapy. The rapid proliferation of devices being developed to better diagnose and treat peripheral arterial disease makes it difficult to compare device effectiveness and cost because “the target keeps moving.” Randomized trials can only be performed against FDA-approved devices. Every case of peripheral arterial disease is different. We have no present means of stratification that allows ideal device selection based on specific characteristics such as the degree of vascular calcification, vessel size, tortuosity, and run-off. We need randomized trials, but we also clearly need an inclusive registry that includes and follows all patients treated with peripheral vascular intervention, including specific lesion characteristics, if we are to ultimately determine what represents the best therapy for specific cases.
