Excimer laser ablation combined with drug-coated balloons improves patency rates of long superficial femoral artery in-stent restenosis compared with plain balloon angioplasty or standalone drug-coated balloons, both in the short term and beyond two-year follow-up. This was the suggestion from Jos van den Berg, Lugano, Switzerland, as he addressed delegates at the New Cardiovascular Horizons annual meeting (1–3 June, New Orleans, USA).
“The problem of treating in-stent restenosis with balloon angioplasty is that there are only three potential mechanisms of luminal gain: tissue compression, extrusion of tissue out of the stent and additional stent expansion—up to 56% of the total luminal gain,” van den Berg said.
For stents in the superficial femoral artery, van den Berg explained that “the problem is that they are self-expanding and are already fully expanded, so when you balloon the stent you have difficulty compressing the tissue and the stent reverts to its normal state after the initial expansion.”
Tissue ablation is a necessity with in-stent restenosis, as although balloon angioplasty provides good acute luminal gain (intra-stent tissue volume decrease of up to 50%), after a short delay (as little as 30 minutes), intra-stent tissue volume can increase by up to 32%.
Several studies—including the DEBATE ISR, FAIR and DCB in SFA-ISR trials—have indicated that drug-coated balloons are a more effective solution than plain balloons, at least in the short-term. That said, at two years, restenotic rates increase, especially with Tosaka class 2 and 3 lesions. At three years, a 2015 study (Grotti et al) found that there was no longer a difference between the two methods. “The treatment of more complex lesions is associated with an increased rate of target lesion revascularisation, irrespective of the technology used,” van den Berg said.
For excimer laser ablation alone (Spectranetics), the PATENT and EXCITE trials showed good initial freedom from target lesion revascularisation and primary patency, but diminished outcomes at later follow-up, with freedom from target lesion revascularisation falling from 87.8% to 64.4% and primary patency from 61.1% to 37.8% at six and 12 months, respectively—, although significantly better than plain balloon angioplasty, “still not good enough,” van den Berg said. The SALVAGE study (combining covered stents and laser ablation) found similar issues with long-term patency, with 48% primary patency at 12 months.
“The use of atherectomy with drug-coated balloons therefore seems like a good solution,” said van den Berg. He cited his own research published from 2014 with 14 patients of mean age 78 years and mean lesion length of 13.2cm. Most (85.7%) of the patients were classified as Tosaka class III with a mean time of occurrence of restenosis after initial treatment of 8.6 months. The data followed-up patients to two years, and saw only one target lesion revascularisation (at three years post-treatment). Duplex follow-up of almost two-years showed one binary restenosis (the same patient with target lesion revascularisation), 25–50% stenosis in four cases and no signs of neointimal hyperplasia in seven patients. In the seven patients with critical limb ischaemia, no major amputations were needed. A larger cohort of patients is currently in follow-up.
“For treatment of Tosaka I lesions, treatment with drug-coated balloons is efficacious in the first two years, after which plain balloons catch up,” van den Berg told delegates. “The results of stent grafting and debulking followed by drug-coated balloons for long in-stent restenosis lesions are probably comparable, although there are conflicting data for stent grafts.”
“Excimer laser ablation followed by drug-coated balloons improves patency rates of long superficial femoral artery in-stent restenosis compared with plain balloons or standalone drug-coated balloons, not only in the short term, but also beyond two years’ follow-up with no late catch-up. Furthermore—and this is one of the biggest advantages of the combined therapy in my opinion—atherectomy plus drug-coated balloon leaves the possibility of future endovascular treatment options open.”