Clinical Pearls & Morning Reports
Published January 3, 2024
Among patients with chronic limb-threatening ischemia (CLTI) and infrapopliteal artery disease, angioplasty has been associated with frequent reintervention and adverse limb outcomes from restenosis. Varcoe et al. conducted a single-blind, randomized, controlled trial to evaluate the safety and efficacy of a new everolimus-eluting resorbable scaffold for the treatment of infrapopliteal artery disease in patients with CTLI. Read the NEJM Original Article here.
Q: What are the challenges of using angioplasty for infrapopliteal artery revascularization?
A: Several trials have evaluated methods for revascularization in the infrapopliteal circulation in an attempt to avoid the poor patency outcomes seen with angioplasty. However, most of these methods have failed because of the complex nature of the atherosclerotic disease and the difficulty of maintaining patency in both the short term and the long term. The challenges associated with infrapopliteal artery revascularization include extensive medial calcinosis, long lesion lengths, acute lesion recoil, and a predilection for flow-limiting dissection after angioplasty.
Q: Have drug-eluting devices been used to treat infrapopliteal artery disease?
A: Drug-eluting devices that inhibit neointimal hyperplasia have not been used routinely for the treatment of infrapopliteal artery disease. In numerous trials of drug-coated balloons and drug-eluting scaffolds and stents, the treatment has not resulted in greater patency than angioplasty or has had practical limitations. Of all the available approaches, the use of coronary drug-eluting stents with sirolimus analogues in below-the-knee interventions has shown the most promise for maintaining primary patency. However, the permanent nature of these metal implants has made some clinicians wary of their routine use.
A: Drug-eluting resorbable scaffolds have potential advantages that may make them suitable for the treatment of infrapopliteal artery disease, and observational studies have shown promising results. Drug-eluting resorbable scaffolds have unique scaffolding properties that allow them to overcome mechanical failure while acting as a delivery platform for an antiproliferative drug during the restenotic phase after intervention. These scaffolds also undergo resorption over time, which facilitates vessel remodeling and potentially reduces the late complications associated with permanent metal stents.
A: For the primary efficacy end point (freedom from amputation above the ankle of the target limb, occlusion of the target vessel, clinically driven revascularization of the target lesion, and binary restenosis of the target lesion at 1 year), the Kaplan–Meier estimate was 74% in the scaffold group and 44% in the angioplasty group, with an absolute difference of 30 percentage points (95% confidence interval [CI], 15 to 46; one-sided P<0.001 for superiority). The primary safety end point (freedom from major adverse limb events at 6 months and perioperative death) was observed in 165 of 170 patients in the scaffold group and 90 of 90 patients in the angioplasty group, with an absolute difference of -3 percentage points (95% CI, -6 to 0; one-sided P<0.001 for noninferiority). The use of the scaffolds in the trial was restricted to the proximal two thirds of the infrapopliteal arteries. Caution must be used in extrapolating these findings to other anatomical locations.