Future of Directional Atherectomy: Debulking Myths, Proving Results

It is no secret that peripheral artery disease (PAD) is a multidimensional disease affecting 8 to 12 million Americans—yet only 2 million even know they have it. With effective therapies now available, disease awareness is building as is the power of highly effective and proven therapies such as directional atherectomy (DA) to restore vital blood flow and resolve PAD in many patients, says James B. Park, MD, medical director of the heart & vascular service line and chair of accountable clinical management at Texas Health Presbyterian Hospital Dallas. If DA isn’t part of your heart and vascular program, it is time to take a closer look.

PAD is a complex disease with more than half of patients not showing classic signs or symptoms. Artery sizes vary as do lesion lengths, locations, and plaque morphologies. The disease’s progressive nature often requires multiple treatments, so preserving future treatment options is desired by doctors and patients.

More than a decade ago, directional atherectomy emerged as a game changer in PAD treatment—kicking off what Park calls an atherectomy explosion. Most atherectomy products serve a niche purpose, such as calcified lesions below the knee and are limited by their mechanism of action. But true versatility is certain with the Covidien TurboHawk directional atherectomy device, which is 6F or 7F sheath compatible. Its unique directional plaque removal design allows physicians to create narrow to wide channels (from 1.5-7 mm in diameter), tackle concentric and eccentric lesions and treat all types of plaque, from soft to heavily calcified.

“A real advantage of the TurboHawk device is its directionality,” says Park, an early pioneer and experienced cardiologist who trains other physicians on a variety of peripheral interventional techniques and devices, including the TurboHawk device. “Because of the directionality of the device, we can achieve a larger, more concentric lumen similar to the patient’s native lumen. We also use the TurboHawk device in areas we prefer not to stent as in the femoral popliteal junction behind the knee or in bifurcating arteries.” For these and more prescriptive uses, Covidien has created Hawk Zones to show where the TurboHawk device excels.

Evidence is proving directional atherectomy works, too. DEFINITIVE LE is the landmark clinical study that verifies the effectiveness of directional atherectomy as a frontline therapy for PAD. The study, published online Aug. 18th in the Journal of the American College of Cardiology – Cardiovascular Interventions, showed significant 12-month results: 95% limb salvage rate for CLI patients; 90% patency in infrapopliteal lesions; 86% patency in claudicants with eccentric lesions; and equivalent patency for diabetic (77%) and non-diabetic patients (78%).

The positive patency results also bode well as we anticipate the debut of drug coated balloons into the U.S. market later this year. Proponents see a certain synergy emerging in DA’s ability to remove plaque burden prior to DCB deployment for better drug delivery and uptake. Early evidence suggests the debulking or removing of calcium, particular heavy calcium (SFA and popliteal) from vessels may positively impact primary patency. The DEBELLUM (Drug-Eluting Balloon Evaluation for Lower Limb Multilevel TreatMent) trial confirmed the ability of paclitaxel-eluting balloons to reduce restenosis v. conventional balloons at six months after treatment of multilevel arterial disease in patients with claudication and critical limb ischemia. (J Endovasc Ther 2012;19:571-580). More investigation, however, is needed to determine efficacy and longer term patency.

“As we see better therapies emerging in the interventional world, we are expanding the scope of patients we can treat,” Park says. “There is a significant number of undiagnosed patients we need to identify, and thus help, with these therapies. In addition, as we treat more complicated patients, we need better devices to treat more complicated lesions.  The versatility of the TurboHawk device comes into play as it allows physicians to treat just about any patient with PAD from early diagnosis with claudication to later stage critical limb ischemia and wound healing.”