Bioresorbable Below-the-Knee Technology Shows Durable Promise for CLTI
The Prince of Wales Hospital and University of New South Wales, Randwick, Australia
During a Thursday afternoon session at the Amputation Prevention Symposium, vascular surgeon Dr Ramon L. Varcoe presented an update on bioresorbable below-the-knee (BTK) technology, highlighting the growing body of evidence supporting the Esprit™ BTK drug-eluting resorbable scaffold (Abbott Cardiovascular) for the treatment of chronic limb-threatening ischemia (CLTI). The presentation focused on the ongoing challenge of achieving durable patency in patients with complex infrapopliteal disease while avoiding the long-term limitations associated with permanent implants.
Dr Varcoe emphasized that percutaneous transluminal angioplasty (PTA) remains the standard of care for BTK interventions, but durability continues to be a significant concern due to high rates of restenosis, repeat revascularization, and associated morbidity. While alternative technologies such as drug-eluting stents, drug-coated balloons, and atherectomy have expanded treatment options, each carries limitations related to anatomy, long-term performance, or supporting clinical evidence. He described the ongoing need for a "leave nothing behind" solution capable of providing temporary vessel scaffolding, sustained drug delivery, and long-term vessel restoration.
The presentation reviewed the design of the Esprit BTK system, a bioresorbable scaffold composed of poly-L-lactic acid that delivers everolimus while providing temporary mechanical support to the vessel. Over approximately 3 years, the scaffold gradually resorbs, leaving only radiopaque markers while preserving future treatment options. This approach is intended to combine the benefits of drug delivery with restoration of normal vessel anatomy after scaffold resorption.
Clinical evidence centered on findings from the LIFE-BTK randomized controlled trial, which enrolled 261 patients with Rutherford class 4 or 5 CLTI and compared the Esprit BTK scaffold with PTA. Three-year data demonstrated sustained clinical benefit, including a 33% relative improvement in the primary efficacy endpoint and a 45% reduction in clinically driven target lesion revascularization compared with angioplasty alone. Dr Varcoe also noted that safety outcomes remained comparable between treatment groups through 3 years, with no evidence of a late safety signal as the scaffold underwent resorption and the vessel remodeled over time.
The session also featured early results from the global Esprit BTK Post-Approval Study, an observational registry evaluating the technology in a more complex real-world patient population characterized by higher rates of diabetes, renal disease, end-stage renal disease, severe calcification, and advanced lesion complexity. Interim 30-day data demonstrated 100% freedom from clinically driven target lesion revascularization, low rates of major adverse limb events, and low mortality despite the higher-risk population. These findings remain consistent with the positive outcomes observed in the randomized LIFE-BTK trial while expanding the evidence base into routine clinical practice.
The presentation concluded with an overview of health economic analyses from LIFE-BTK, which suggested that improved patency and fewer repeat interventions translate into favorable cost-effectiveness when compared with PTA. Trial data indicated lower adjusted event rates over two years with only modest incremental costs, resulting in a high probability that the technology represents a cost-effective treatment strategy for patients with infrapopliteal artery disease and CLTI.
