Results of the DISRUPT PAD study show that Lithoplasty, a new balloon-based technology, demonstrates safety and efficacy in the treatment of superficial femoral artery and popliteal artery disease. Early results with the technology were presented at a late-breaking trial session at the Vascular Interventional Advances conference (VIVA, 4–7 November, Las Vegas, USA).
DISRUPT PAD is a single-arm, multicentre study evaluating the safety and effectiveness of Lithoplasty balloon catheters (Shockwave Medical) for the treatment of peripheral arterial disease. Lithoplasty is a novel balloon-based technology that utilises integrated lithotripsy, a pulsatile mechanical energy commonly used to break up kidney stones, to disrupt both superficial and deep calcium and normalise vessel wall compliance prior to low-pressure balloon dilatation. Lithoplasty is designed to be naturally gentle to soft tissue (non-diseased portions of the vessel) while remaining hard on calcium.
Early clinical evaluation from 35 patients (28 in Austria and seven in New Zealand) with calcified vascular stenosis of the superficial femoral artery and popliteal artery demonstrated safe and effective dilatation of calcified stenosis with no acute failures, favourable residual stenosis, and no reintervention out to 30 days, with no major adverse events. Primary efficacy results demonstrated 100% success, defined as ability to achieve less than 50% residual stenosis using Lithoplasty with or without adjunctive angioplasty. Device success was 87%, defined as ability to achieve less than 50% residual stenosis using Lithoplasty alone. Importantly, an average residual stenosis of 23% (initial 76%), with no difference in the ability to dilate lesions between moderate (36%) and severely (64%) calcified lesions, was noted. Thirty-day patency assessed by duplex ultrasound was 100%.
“Calcified vascular lesions remain a major impediment to modern percutaneous therapy for vascular disease,” said Marianne Brodmann, Medical University of Graz, Austria, principal investigator of the study, who presented the results at the conference. “The results of this trial demonstrate that, unlike current devices that treat only superficial calcium, the Lithoplasty system promises to be effective on all types of calcium, including deep calcium—the type known to limit vessel expansion.”
She added: “The procedure was extremely well tolerated and had an excellent safety profile. Clinical pain and walking scores at 30 days were excellent. Peak velocity ratios suggest positive remodelling effects at 30 days and warrant further investigation. Longer-term vessel patency will be determined by duplex ultrasound at six months of follow-up.”
First-in-man results
Results from the first-in-man study of five patients with moderate to severe coronary calcification presented in September at the annual TCT conference in Washington, DC demonstrated safety, tolerability, deliverability, and effectiveness for Lithoplasty as a pre-treatment of calcified coronary lesions prior to stenting.
“Disruption of calcium within the vessel wall with Lithoplasty enables the use of low balloon pressures to dilate lesions and improve blood flow. This has the potential to minimise barotrauma and soft tissue vascular injury common to traditional balloons and existing endovascular technologies – an exciting breakthrough for patients with difficult-to-treat coronary calcifications, which continues to be a major problem in cardiology today,” said Todd Brinton, co-founder of Shockwave Medical and clinical associate professor of interventional cardiology, Stanford University. “We look forward to confirming these promising findings in additional future studies, including the European multicentre DISRUPT CAD study planned for next year.”
