Currently, there are several planned and ongoing studies investigating the use of drug-eluting balloons for peripheral revascularisation. Nicolas Diehm, angiologist, Bern, Switzerland, gave an overview at LINC 2010. Diehm reported that enrolment has been completed for the Advance 18 PTX study investigating Cook’s Advance balloon with paclitaxel with non-disclosed matrix coating in the femoropopliteal arteries. Lutonix’s balloon with paclitaxel with non-disclosed matrix coating is under investigation in the LEVANT I study, for which enrolment has been completed. Currently enrolling, Diehm told delegates, is the Elutax femoropopliteal stent versus stent plus drug-eluting balloon versus atherectomy study. Aachen Resonance’s second generation of the Elutax drug-eluting balloon has two layers of paclitaxel, the first on the inflated balloon and the second as a crystal powder. Also enrolling is the In.Pact Deep and FAIR studies investigating Invatec’s paclitaxel-eluting In.Pact balloon.
Diehm also reported on the planned RIVER study: A prospective, multicentre, randomised trial for the safety and efficacy of paclitaxel-coated balloon angioplasty using the proprietary Paccocath technology (Cotavance, Medrad Interventional/Possis) vs. plain balloon angioplasty for the prevention of restenosis in atherosclerotic lesions of the femoropopliteal arteries. The primary efficacy endpoint is duplex-determined binary restenosis rate at 12 months, he told delegates. The COPA CABANA trial, he continued, is a further study investigating Cotavance Paccocath versus uncoated balloon angioplasty for the treatment of in-stent restenosis in peripheral arteries, with a primary efficacy endpoint of late lumen loss at 12 months and important secondary endpoints of freedom from restenosis at 6, 12 and 24 months.
Dierk Scheinert, University of Leipzig, Germany, reviewed current data on drug-eluting balloons in Europe at ISET 2010. THUNDER, FemPac, Paccocath ISR I and II, and PEPCAD II were highlighted as successful trials, while Piccoleto and PEPCAD III were failures, he said.
From his own experience at Leipzig with drug-eluting balloons below the knee, Scheinert reported a restenosis rate of 31% with drug-eluting balloons vs. 69% for plain balloons. Furthermore, diffuse restenosis/reocclusion was reported as 15% with a drug-eluting balloon, compared with 56% with a plain balloon. In terms of limb salvage, freedom from symptoms and time to healing, Scheinert concluded by posing a question to the audience: Will drug-eluting balloons improve results for patients with below-the-knee obstructions? The answer, it seems, is yet to be found, as further investigation into the new technology is needed.
The first clinical results of the In.Pact Amphirion trial in below-the-knee lesions were reported at LINC 2010 by Andrej Schmidt, leading investigator from the Park Hospital Leipzig, Germany. Preliminary results indicate a reduction in restenosis with the balloon. “Sixty nine per cent of critical limb ischaemia patients with long lesions show restenosis after three months. The drug-eluting balloon was able to bring this number down to 31%. Considering the mean lesion lengths of 17 cm and 58% rate of total occlusions prior to intervention, these results have the potential to change the way we treat complex critical limb ischaemia,” Schmidt said. Dierk Scheinert, principal investigator of the In.Pact Amphirion register, commented, “It took us several years to develop adequate techniques to successfully re-open below-the-knee arteries but we had no means of preventing restenosis for longer arterial segments. Drug-eluting stents are only feasible in short lesions. The drug-eluting balloon is the first method that brings down restenosis rates in those complex critical limb ischaemia cases. An interesting observation is also the nature of the restenosis, if it appears after treatment with a drug-eluting balloon: we see focal segments, not re-narrowing along the total artery. This makes re-intervention less complex.”
Drug-eluting balloons are clearly becoming an area for big investment for medical device firms, but the jury is still out despite early promise.