A feasibility study of the JetStream XC atherectomy device (Boston Scientific) has shown high rates of procedural success, no device-stent interaction, and favourably low target lesion revascularisation (TLR) rates when treating femoropopliteal in-stent restenosis. The study has been published in the Journal of Endovascular Therapy.
Lead author Nicolas W Shammas, Midwest Cardiovascular Research Foundation, Davenport, USA, and colleagues explain that femoropopliteal in-stent restenosis is highly prevalent, occurring in more than one third of patients at one year and up to 49% at two years. Complex lesions (lengthy, TASC II C/D, and total occlusions), certain patient characteristics (female gender, diabetes mellitus), critical limb ischaemia, and significant stent fractures are associated with a higher rate of restenosis.
Treatment of in-stent restenosis of the femoropopliteal segment using conventional balloon angioplasty “is associated with a high rate of restenosis”, the authors write. “Recently, laser atherectomy was shown to reduce TLR at six months and one year when compared with balloon angioplasty alone… however, a significant loss of patency and a higher TLR rate were seen at one year.”
The JetStream XC atherectomy device, a rotational cutter with aspiration capacity, was evaluated in a prospective cohort of 29 patients (mean age 69.9±11.7 years; 11 men, 18 females) with femoropopliteal in-stent restenosis in 32 limbs, treated in one of two centres. Lesion length was 17.4±13.1cm. The primary effectiveness outcome was acute success (≤30% residual narrowing with no serious adverse events), while the primary safety endpoint was the incidence of major adverse events. Secondary endpoints included clinically driven target lesion revascularisation rates at six months and one year, and loss of stent integrity as assessed by an angiographic core laboratory.
The authors report that “acute success was obtained in 29/32 (91%) limbs, and acute device success (<50% residual narrowing after atherectomy alone) was 76% (22/29).” Adjunctive balloon angioplasty was performed in all cases at a mean pressure of 11.6±3.3atm. Embolic filter protection was used in 16 (50%) of 32 limbs, with macrodebris noted in two (12%) of 16 filters. Distal embolisation requiring treatment occurred in 3/32 (9.4%) limbs (two with no filter). Other non-procedure-related adverse events were one (3%) nonvascular death and one (3%) case of major bleeding. There were no new stent fractures or deformities (n=24) observed post-atherectomy by core laboratory evaluation. Follow-up was completed on 27 patients (29 limbs) at six and 12 months. TLR rates at these points occurred in 4/29 (14%) and 12/29 (41%) patients. Patency (duplex-derived peak systolic velocity ratio <2.4) was 72% at six months. The total treated lesion length in this study was 19.5±12.9cm.
“The JetStream XC appears to be effective in treating femoropopliteal in-stent restenosis,” suggest Shammas et al. “High patency and favourable TLR rates were seen at six months and one year despite long lesions. Adverse events consisted of relatively few cases of distal embolisation requiring additional treatment, which was in the range seen with other atherectomy devices. Quantitative vascular angiography was performed on all limbs, providing objective measurements of lesion severity; core laboratory analysis of stent integrity found no adverse stent-device interaction. The study is limited by its small number of patients, and larger multicentre prospective registries are needed to confirm these findings.”
Shammas and colleagues also suggest that by combining atherectomy with drug-coated balloon treatment, even better outcomes could potentially be achieved, as “atherectomy may allow deeper and higher antiproliferative drug diffusion in the vessel wall that may lead to more durable and effective results in inhibiting smooth muscle cell proliferation. Studies are currently ongoing to test this hypothesis.”