Results from a feasibility study conducted in Italy indicate that ultrasound-enhanced paclitaxel delivery inhibits arterial smooth muscle proliferation after balloon angioplasty in peripheral arterial disease. Costantino Del Giudice, Department of Radiology, University Hospital Tor Vergata, Rome, Italy, spoke about the study at the EuroPCR congress (19–23 May, Paris, France).
Del Giudice, who spoke about “Ultrasound-enhanced delivery of paclitaxel to femoropopliteal artery in patients with Rutherford category 4–6” and conducted the study with Roberto Gandini, noted that ultrasound has been used in several medical therapies. “Ultrasound energy at 20KHz frequency is capable of inducing cellular change and modifying calcific plaque compliance and may be useful to enhance delivery of drugs to challenging lesions,” he said.
He explained that CardioProlific has developed a system for ultrasound-enhanced acute delivery of paclitaxel to peripheral arterial lesions, and commented: “Ultrasound energy is used to change lesion compliance and increase vessel permeability and contrast agent is used to deliver paclitaxel to the vessel wall.”
According to Del Giudice, the target lesion is treated with balloon angioplasty only. The ultrasound catheter is then introduced in the treatment area and the vessel wall is exposed to ultrasound energy for 60 seconds. A flow protection balloon catheter is positioned distally to the treatment area, inflated, and a mixture of paclitaxel and contrast medium (1.0µg/mm2) is delivered to the treated lesion for at least 60 seconds. Finally, the mixture of paclitaxel and contrast is aspirated from the body.
The study employing the system was conducted at the University Hospital Tor Vergata. The primary endpoint (safety) was freedom from major adverse cardiac events at 30 days (including death, amputations, bypass surgery, myocardial infarction), and the secondary endpoint was procedural success (angiographic restenosis at six months and target lesion revascularisation at six and 12 months).
The study enrolled 21 patients aged 74.2±7.5 years, and 80% were men. At six months, Del Giudice said that the restenosis rate was 5%, and there were no reinterventions, amputations or deaths. He added that there was one reintervention at 12 months and the patient died of bowel ischaemia.
“The technology is suitable for superficial femoral and popliteal arteries, with the advantage of not having an implant. It is simple to perform, with easy-to-use hardware and catheter, and is quick and safe. It is also efficient and cost-effective,” he said.
He concluded by saying that the human feasibility study indicates that ultrasound-enhanced arterial paclitaxel delivery inhibits smooth muscle proliferation after balloon angioplasty, fits well with standard peripheral interventional techniques and represents a non-implant solution with homogenous drug delivery to the vessel wall. He added that “encouraging results in challenging cases demonstrate a great potential for this technology for critical limb ischaemia patients. A larger clinical study is required to validate this promising new approach”.