AMS INSIGHT—Absorbable Metal Stent Implantation for Treatment of Below-the-Knee Critical Limb Ischemia: 6-Month Analysis

Abstract

Endoluminal treatment of infrapopliteal artery lesions is a matter of controversy. Bioabsorbable stents are discussed as a means to combine mechanical prevention of vessel recoil with the advantages of long-term perspectives. The possibility of not having a permanent metallic implant could permit the occurrence of positive remodeling with lumen enlargement to compensate for the development of new lesions. The present study was designed to investigate the safety of absorbable metal stents (AMSs) in the infrapopliteal arteries based on 1-and 6-month clinical followup and efficacy based on 6-month angiographic patency. One hundred seventeen patients with 149 lesions with chronic limb ischemia (CLI) were randomized to implantation of an AMS (60 patients, 74 lesions) or stand-alone percutaneous transluminal angioplasty (PTA; 57 patients, 75 lesions). Seven PTA-group patients ''crossed over'' to AMS stenting. The study population consisted of patients with symptomatic CLI (Rutherford categories 4 and 5) and de novo stenotic ([50%) or occlusive atherosclerotic disease of the infrapopliteal arteries who presented with a reference diameter of between 3.0 and 3.5 mm and a lesion length of \15 mm. The primary safety endpoint was defined as absence of major amputation and/or death within 30 days after index intervention and the primary efficacy endpoint was the 6-month angiographic patency rate as confirmed by core-lab quantitative vessel analysis. The 30-day complication rate was 5.3% (3/57) and 5.0% (3/60) in patients randomized for PTA alone and PTA followed by AMS implantation, respectively. On an intention-totreat basis, the 6-month angiographic patency rate for lesions treated with AMS (31.8%) was significantly lower (p = 0.013) than the rate for those treated with PTA (58.0%). Although the present study indicates that the AMS technology can be safely applied, it did not demonstrate efficacy in long-term patency over standard PTA in the infrapopliteal vessels.

In vitro and in vivo cytocompatibility evaluation of biodegradable magnesium-based stents: a review

“…Up to now, the yttrium, rare earth and zirconium containing Mg alloy WE43 might be the only Mg-based alloy used for vascular stent in clinical trials, such as the Absorbable Metal Stent (AMS) [11,41,42,[44][45][46]49,50] and Magic stent [47,48], which are two most frequently investigated stents in clinical trials. Besides coronary arteries [42,43,45,46] also peripheral arteries [41,44], pulmonary arteries [11,47,49] and other lesions [44,50] have been stented.…”

“…Besides coronary arteries [42,43,45,46] also peripheral arteries [41,44], pulmonary arteries [11,47,49] and other lesions [44,50] have been stented. CA and IVUS are the main follow-up tools to investigate the stented arteries.…”

“…. . little complications [11,41,43,44,46] in the early stage of the implantation, as well as hardly any scaffold thrombosis [11,43,45,46]. It is worth noting that the first clinically proven Mg-based stent DREAMS 2G (Magmaris) received CE mark approval in June 2016, and has shown very encouraging clinical data on endothelialization, radial resistance, recoil, and degradation properties.…”

“…This is a milestone-the first clinical trial of biodegradable Mgbased vascular stents. A series of follow-up clinical trials also obtained positive results, such as Magic Stent, DREAMS, DREAMS 2G (Magmaris) and so on [11,[41][42][43][44][45][46][47][48][49][50]. It is worth mentioning that the Magmaris stent received CE mark approval in June 2016, and it shows very encouraging clinical data on endothelialization, radial resistance, recoil, thrombosis and degradation properties.…”

Biodegradable Stents: Biomechanical Modeling Challenges and Opportunities

“…Restenosis occurred as a result of neointimal growth and negative remodeling, often attributed to the early loss of radial support due to fast degradation and absorption of the stent. In infrapopliteal lesions in patients with limb ischemia (AMS INSIGHT), the stent has not performed well either: Bosiers et al 9 did not observe long term patency over angioplasty.…”