[Drug-coated balloons in the treatment of peripheral artery disease (PAD). History and current level of evidence]

An ultralow dose paclitaxel coated drug balloon with an outer protective sheath for peripheral arterial disease treatment

Use of a drug-eluting coated balloon (DCB) represents a promising therapeutic method for peripheral arterial disease (PAD) due to its advantages such as no implant permanently retained in the patient and no inflammatory reaction and endothelialization barrier caused by a permanent stent. However, there is still a huge challenge of controlling the release of drugs from the DCB into vessel tissue. The uncontrolled release of drugs and high drug loading amounts could potentially lead to distal embolization and mortality events. In our study, an ultralow dose paclitaxel (PTX) coated DCB appended with an outer protective sheath was designed to treat peripheral vessel stenosis. An in vitro study demonstrated that the sheath could significantly reduce the drug loss during the delivery process and the meglumine matrix could effectively promote the transfer of PTX into vessel tissue. The pharmacokinetics study in the swine model also demonstrated that the PTX amount remaining in the vessel after being treated by our DCB was comparable to similar products on market although only less than a third of the PTX was used. The safety study indicated that the DCB treatment did not have any adverse impact on the physiological function of the vessel. Therefore, our ultralow dose PTX coated DCB could provide an effective and safe treatment for PAD.

Balloon Angioplasty of Infrapopliteal Arteries: A Systematic Review and Proposed Algorithm for Optimal Endovascular Therapy

Endovascular revascularization has been increasingly utilized to treat patients with chronic limb-threatening ischemia (CLTI), particularly atherosclerotic disease in the infrapopliteal arteries. Lesions of the infrapopliteal arteries are the result of 2 different etiologies: medial calcification and intimal atheromatous plaque. Although several devices are available for endovascular treatment of infrapopliteal lesions, balloon angioplasty still comprises the mainstay of therapy due to a lack of purpose-built devices. The mechanism of balloon angioplasty consists of adventitial stretching, medial necrosis, and dissection or plaque fracture. In many cases, the diffuse nature of infrapopliteal disease and plaque complexity may lead to dissection, recoil, and early restenosis. Optimal balloon angioplasty requires careful attention to assessment of vessel calcification, appropriate vessel sizing, and the use of long balloons with prolonged inflation times, as outlined in a treatment algorithm based on this systematic review. Further development of specific devices for this arterial segment are warranted, including devices for preventing recoil (eg, dedicated atherectomy devices), treating dissections (eg, tacks, stents), and preventing neointimal hyperplasia (eg, novel drug delivery techniques and drug-eluting stents). Further understanding of infrapopliteal disease, along with the development of new technologies, will help optimize the durability of endovascular interventions and ultimately improve the limb-related outcomes of patients with CLTI.

Current evidence of drug-elution therapy for infrapopliteal arterial disease

New and sophisticated endovascular devices, such as drug-eluting stents (DES) and drug-coated balloons (DCB), provide targeted drug delivery to affected vessels. The invention of these devices has made it possible to address the reparative cascade of arterial wall injury following balloon angioplasty that results in restenosis. DESs were first used for the treatment of infrapopliteal lesions almost 20 years ago. More recently, however, DCB technology is being investigated to improve outcomes of endovascular below-the-knee arterial procedures, avoiding the need for a metallic scaffold. Today, level IA evidence supports the use of infrapopliteal DES for short to medium length lesions, although robust evidence that justifies the use of DCBs in this anatomical area is missing. This review summarizes and discusses all available data on infrapopliteal drug-elution devices and highlights the most promising future perspectives.

Endovascular treatment of femoro-popliteal lesions

Peripheral artery disease (PAD) is a major health concern affecting more than 200 million people worldwide and studies have shown PAD to be a strong predictor of mortality, morbidity, and disability. The management of PAD is multi-tiered and advancements in technology have given physicians more options for endovascular revascularization if medical therapy does not result in substantial improvement. Many randomized controlled trials have reported efficacy of various therapies including laser atherectomy, stent technology, and drug-coated balloons over standard percutaneous transluminal angioplasty; however, uncertainty regarding the best standard of care remains unclear because of a lack of head to head comparisons between novel therapies. Furthermore, variability in the reported clinical outcomes exists and makes it difficult to evaluate the superiority of any specific treatment modality, especially for functional capacity and quality of life. Recently established consensus definitions for clinical outcomes coupled with investigators incorporating direct comparisons within clinical trials will be crucial to establish consistent care and meaningful gain in treatment for these patients. This review will highlight the treatment modalities, literature supporting each treatment modality, and insight into why they are being used and why variation exists around the United States.