Bioresorbable Scaffold Shows Sustained Promise in Superficial Femoral and Iliac Artery Lesions

LAS VEGAS, NV—As researchers investigate how a bioresorbable scaffold (BRS) might fit into the treatment paradigm for peripheral vascular disease, a small study suggests that an everolimus-eluting device may provide good functional improvement for patients with symptomatic claudication.  

Reporting the 3-year results of the ESPRIT I trial yesterday at VIVA 2016, Michael R. Jaff, DO (Massachusetts General Hospital, Boston, MA), said no new events were seen in the cohort between years two and three of follow up. Additionally, he indicated that proper sizing of vessel diameter prior to placing the scaffold appears to be the key to keeping event rates low.

In a press conference prior to his presentation, Jaff was asked how long he thought it would be before the technology could be commercially available in the United States.

“I think it’s going to be a long time,” he observed, noting that a much larger trial is needed to define the role of the technology for this patient population.

Patency, Symptom Relief Sustained

The first-in-human study involved 35 patients at seven centers in Europe who had lesions located in either the superficial femoral artery (SFA; 89%) or external iliac artery (11%). In prior presentations, the investigators have reported no procedure or device-related deaths or amputations to 2 years of follow-up with the everolimus-eluting, bioresorbable ESPRIT device (Abbott Vascular).

The 3-year data expand on and confirm those findings by showing that patency continues to be sustained, as does symptom relief. Freedom from ischemia-driven TLR, which was 88.1% at the 2-year follow up, remained the same at 3 years, a finding that Jaff said he was “pleasantly surprised” to see.

As has been previously reported, four patients in the trial had improper sizing of the BRS due to operators selecting arteries with diameters that were larger than the 6.5-mm upper limit cutoff set by investigators. Jaff showed that when those cases were removed from the analysis, the overall TLR rate dropped from 13.8% to 8% at 3 years. In the press conference, he noted that the inclusion of external iliac arteries, which tend to be larger than SFAs, was challenging for some operators when assessing vessel size.

In terms of safety, he noted that there continue to be no amputations or bypasses of the treated limb in any patients since the start of the study. Rates of scaffold thrombosis and death at 3 years were 3.4%, respectively, representing one instance of each. The scaffold thrombosis occurred in one of the four cases of oversizing. Additionally, Jaff said nearly 90% of the cohort was in Rutherford class 0 or 1, indicating no or minimal symptoms.

What Does the Future Hold?

“Going forward, it’s early but there’s a lot of excitement for obvious reasons [for] a technology that . . . in the coronaries has shown good results,” noted moderator Michael Dake, MD (Stanford University Medical Center, Stanford, CA). He then asked panelist Christopher Metzger, MD (Wellmont CVA Heart Institute, Kingsport, TN), where he sees this type of BRS fitting into management choices for peripheral artery disease.

Echoing the ‘leave no metal behind,’ theme that has been prevalent here at VIVA 2016, Metzger said if the scaffolds are shown to perform well in longer lesions “it would be very nice to not have a permanent implant if you didn’t need it” given all the biological forces at work in the leg.

In the earlier press conference, Jaff acknowledged the limitation of treating only short lesions in the study, agreeing that it must be addressed. “Because if you don’t, you’ll either stack a bunch of [BRS] and that likely will change the outcomes of the patients who are treated, or you have to go back and design a longer device,” he observed.

Jaff also noted that while effort is being put into cost-effectiveness research in this area, this too could impact the role of these devices in longer lesions.