Different Techniques for the Improvement of Outcomes in Intermittent Claudication

Peripheral vascular diseases affect over 20% of the population and can affect up to 30% of people with cardiovascular risk factors.

The most important treatment points include modification of risk factors, exercise, optimal medical treatment, and timely revascularization.

Given its lower risk of peri-procedural complications (when compared to surgery), endovascular therapy is generally the first option for revascularization in patients with syptomatic peripheral vascular disease.

As opposed to most arterial beds, for which stent implantation has proven to be superior to other options, we are still arguing about the best strategy for the surface femoral artery.

Also read: “Peripheral Artery Disease Associated to Ischemic and Bleeding Events After DES Implantation.”

Stents solve the problem of elastic recoil, residual stenosis, and flow-limiting dissections, and they can be used in long, extremely calcified lesions. However, the surface femoral artery is subject to forces producing longitudinal stretching, external compression, torsion, and flexing, which might lead to stent fractures and eventual restenosis.

Paclitaxel-eluting stents have proven their safety and efficacy, but their outcomes are not as good as those for coronary stents. Drug-eluting balloons followed by stenting are an alternative to drug-eluting stents, one that presents the advantage of resorting to prosthesis implantation only when needed.

Directional atherectomy is also an alternative for which there is few evidence but much enthusiasm.

The result of all of this was the design of the ISAR-STATH study, which enrolled 1055 prospective patients with symptomatic de novo lesions in the surface femoral artery (70%-100% stenosis). This population was randomized to three groups: drug-eluting balloon plus stenting (n = 48), plain balloon plus stenting (n = 52), and directional atherectomy with distal protection and bailout stenting (n = 55). The primary endpoint was angiographic restenosis at 6 months. Other endpoints were the target lesion revascularization rate, thrombosis, amputation, binary restenosis, and all-cause mortality at 6 and 24 months.

Also read: “Missed Opportunities with Patients with Peripheral Vascular Disease.”

Baseline characteristics were comparable in all groups with a mean lesion length of 65.9 ± 46.8 mm and 56% chronic total occlusions.

At 6 months, angiography showed that percent stenosis was significantly lower in patients treated with paclitaxel-eluting balloon followed by stenting (34 + 31%) as compared with patients who received plain balloon followed by stenting (56 ± 29%, p = 0.009), or directional atherectomy (55 ± 29%, p = 0.007).

Similarly, binary restenosis was significantly lower and clinical follow-up at 24 months was better after treatment with drug-eluting balloon plus stenting.

There were no differences in thrombosis or mortality rates, and no patient required amputation.

Conclusion

Treatment of de novo superficial femoral artery lesions with paclitaxel-eluting balloon followed by stenting is superior to plain balloon and stenting, and directional atherectomy regarding angiographic restenosis at 6 months and revascularization rates at 2 years.

Editorial

This study has resulted in few answers and many questions.

Something that is apparently clear is that directional atherectomy does not seem to contribute any benefit, but it adds considerable technical complexity.

Another conclusion is that stenting is not required by default after balloon angioplasty (whether with a drug-eluting balloon or not). While many cases include dissection after balloon angioplasty, stenting is only necessary in flow-limiting dissections.

A study published by John R. Laird in JACC 2015 assessing drug-eluting stents at 24 months showed a revascularization rate of 9.1% (17% in this study) and bailout stenting was used in only 7.3% of patients. Overall, outcomes seem to be similar, with over 90% of unnecessary stents.

The most notorious absence in this study is that of paclitaxel-eluting stent Zilver PTX, which showed a revascularization yearly rate of 15.3% in the work published by Hiroyoshi Yokoi. While such revascularization rate is higher, lesions were indeed much more complex (mean length of 140.7 mm) and more than doubled the number of lesions in this work.

A great mystery put forward by this study was the low success rate in total occlusions. Actually, in 62% of all cases, lesions were impossible to get through. With such rates, total occlusions should not have been included or the protocol should have allowed for the use of some kind of reentry device.

Comparing published studies on this pathology according to device used, lesion complexity, and clinical severity for enrolled patients is undoubtedly difficult.

Original title: Randomized Comparison of Paclitaxel-Eluting Balloon Angioplasty Plus Stenting Versus Standard Balloon Angioplasty Plus Stenting Versus Directional Atherectomy for Symptomatic Femoral Artery Disease (ISAR-STATH).

Reference: Ilka Ott et al. Circulation. 2017 Jun 6;135(23):2218-2226.

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