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Mar 15, 2017
There is renewed interest from industry, payers and all specialists in advancing the care of patients with peripheral artery disease and critical limb ischemia. The current state and future of endovascular therapies for PAD are rapidly advancing and multidisciplinary collaboration is key for the diagnosis, treatment and follow-up of CLI.
A Decade of Advances
Significant advances in the field of vascular medicine have occurred in the last decade.
Devices including drug-eluting stents, drug-coated balloons and wire interwoven fracture-resistant stents have changed our treatment approach for most lesions.
Furthermore, technical advances such as the tibiopedal retrograde approach or direct stent puncture have increased success rates, but also improved efficiency.
More importantly, we now have 3- to 5-year level 1 data to support endovascular therapy for most devices, and head-to-head trials are underway.
Other advances include more widespread use of the concept of the “team approach” and the BEST-CLI trial, an NIH-sponsored clinical trial to evaluate endovascular vs. open revascularization using a multidisciplinary decision algorithm, which may be completed as soon as late 2018.
Importance of a Multidisciplinary Approach
It is now clear that the best therapy can only be offered by breaking departmental and specialty barriers so that the most efficacious, cutting-edge therapies can be offered to each patient. As part of this, vascular surgeons, interventional cardiologists, interventional radiologists, podiatrists, vascular medicine specialists, plastic surgeons, endocrinologists, nephrologists and internists are all working together to preserve limbs and save lives.
There has also been significant collaboration by all societies on behalf of patients with PAD and CLI. The recent American Heart Association and American College of Cardiology Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease are a reflection of these efforts.
Also, the recent coalition of seven professional societies and organizations that presented at the 2016 MEDCAC meeting highlights the collective efforts by all those involved in helping the care of patients with PAD and CLI. After hearing about these efforts, the panel voted it has moderate confidence that there is sufficient evidence for at least one intervention that improves asymptomatic PAD in the long term, intermittent claudication in the short and long term and CLI in the long term; and moderate-to-high confidence that there is sufficient evidence for at least one intervention that improves CLI in the short term.
Clearly, there is much work to be done, but the groundwork has been set.
Challenges Remain
I, along with other leaders in this area, recently published two papers on the current state and future of treatment of PAD and CLI. The PAD statement was published in Circulation and the CLI statement in the Journal of the American College of Cardiology. In these articles, we recognized the many advances in these areas, but also the many challenges that lie ahead.
Such challenges include greater awareness of PAD among individuals with ulcers and gangrene at risk for amputation, so that no patient who is eligible for limb salvage should ever undergo an amputation prior to obtaining noninvasive testing. Other areas of need include better tools to assess perfusion, especially intraoperatively, so that endovascular specialists have objective measures to guide their interventions.
Beyond endovascular procedures, other therapies such as pharmaceuticals or biologics may also one day play a significant role; however, to date, they have yielded mixed results. Understanding the failure mode and identifying new therapies will have significant impact on PAD and CLI. Such efforts are ongoing. The STOP-PAD trial is currently enrolling patients with CLI who have undergone open or endovascular revascularization but continue to have hypoperfusion as measured by toe-brachial index (TBI). These patients will receive subcutaneous injections of stromal drive factor-1 (SDF-1) in the foot and ankle, with the goal of improving angiogenesis and foot perfusion. Other therapies such arterial flow pumps, hyperbaric oxygen therapies and spinal nerve blocks have shown mixed results, and their use continues to be controversial.