An ultralow dose paclitaxel coated drug balloon with an outer protective sheath for peripheral arterial disease treatment

Use of a drug-eluting coated balloon (DCB) represents a promising therapeutic method for peripheral arterial disease (PAD) due to its advantages such as no implant permanently retained in the patient and no inflammatory reaction and endothelialization barrier caused by a permanent stent. However, there is still a huge challenge of controlling the release of drugs from the DCB into vessel tissue. The uncontrolled release of drugs and high drug loading amounts could potentially lead to distal embolization and mortality events. In our study, an ultralow dose paclitaxel (PTX) coated DCB appended with an outer protective sheath was designed to treat peripheral vessel stenosis. An in vitro study demonstrated that the sheath could significantly reduce the drug loss during the delivery process and the meglumine matrix could effectively promote the transfer of PTX into vessel tissue. The pharmacokinetics study in the swine model also demonstrated that the PTX amount remaining in the vessel after being treated by our DCB was comparable to similar products on market although only less than a third of the PTX was used. The safety study indicated that the DCB treatment did not have any adverse impact on the physiological function of the vessel. Therefore, our ultralow dose PTX coated DCB could provide an effective and safe treatment for PAD.

An Update on Endovascular Therapy of the Lower Extremities

Considerable advances have been made over the last decade in percutaneous technology for treatment of atherosclerotic diseases in the iliac, femoropopliteal, and distal tibioperoneal arteries. While treatment strategies are well defined in the iliofemoral segment, where angioplasty and stenting perform well in appropriately selected lesions, the search for a durable transcatheter therapy for femoropopliteal and distal occlusive disease continues. The spectrum of treatment alternatives to angioplasty ranges from transcatheter plaque excision to laser ablation, rotational atherectomy, cryoplasty, brachytherapy, and stenting. We review in this article the status of percutaneous endovascular techniques for the treatment of lower extremity vascular occlusive disease.

Gender Differences in Outcome after Stent Treatment of Lesions in the Femoropopliteal Segment

Background and Aims:

Although endovascular stent treatment is increasingly used in infrainguinal atherosclerotic occlusive disease, outcome with focus on gender differences has not been reported in detail.

Material and Methods:

One hundred and twelve consecutive patients (67 [60%]) women, undergoing endovascular nitinol stent treatment of atherosclerotic lesions in the femoropopliteal segment were analysed concerning improvement in ankle brachial index (ABI), reinterventions, complications, amputation and survival rates up to 12 months after intervention. Risk factors for amputation and death were analyzed with logistic regression.

Results:

At presentation, women showed critical limb ischemia (CLI) more often than men (87% vs. 58 %; P = 0.001). After 12 months ABI had improved (from 0.40 ± 0.26 at baseline to 0.86 ± 0.22 after 12 months, P < 0.001), but 16 patients (15%) had been amputated and 27 patients (24 %) had died. After adjustment for age, diabetes mellitus and smoking, female gender was an independent risk factor for amputation (OR 9.0; 95% CI 1.1–76.5; P = 0.045).

Conclusions:

Stent treatment of lesions in the femoropopliteal segment had favourable effects on ABI and limb salvage. Treated women more often had CLI and ran a higher risk for amputation within 12 months than men. This might reflect failure of clinicians to adequately appreciate symptoms of atherosclerotic leg artery disease in women.

Past, present and future of femoropopliteal stenting

Endovascular stent implantation was introduced to femoropopliteal procedures almost 2 decades ago. Initial results with balloon-expandable stainless steel stents and self-expanding Elgiloy stents, however, were disappointing. In particular, recurrence rates after long-segment femoropopliteal stenting were catastrophically high, in the range of 60% to 80% at 1 year. Also, attempts to resolve the problem of in-stent restenosis (ISR) using first-generation covered stent-grafts led to unsatisfactory results, high procedural complication rates due to large introducers, and a high incidence of graft thrombosis, which did not make these devices convincing alternatives to bare metal stents. After years of stagnation, however, recent developments in femoropopliteal stent technology have been promising. Self-expanding nitinol stents have been evaluated in several prospective studies. Initial problems with stent fractures seem to be resolved using second-generation devices; for the first time, stenting has been shown to be beneficial compared to balloon angioplasty in longer femoropopliteal lesions. Nevertheless, although superior to balloon angioplasty, nitinol stenting is still associated with a considerable restenosis rate, and treatment of ISR remains problematic. Future concepts to further improve long-term patency after femoropopliteal stenting therefore are under investigation, including drug-eluting stents, biodegradable stents, and coated stent-grafts. From a current perspective, femoropopliteal stenting remains the Achilles' heel of the interventionist.

An update on endovascular therapy of the lower extremities

Considerable advances have been made over the last decade in percutaneous technology for treatment of atherosclerotic diseases in the iliac, femoropopliteal, and distal tibioperoneal arteries. While treatment strategies are well defined in the iliofemoral segment, where angioplasty and stenting perform well in appropriately selected lesions, the search for a durable transcatheter therapy for femoropopliteal and distal occlusive disease continues. The spectrum of treatment alternatives to angioplasty ranges from transcatheter plaque excision to laser ablation, rotational atherectomy, cryoplasty, brachytherapy, and stenting. We review in this article the status of percutaneous endovascular techniques for the treatment of lower extremity vascular occlusive disease.

Primary Patency of Long-Segment Self-Expanding Nitinol Stents in the Femoropopliteal Arteries

PURPOSE

To report a retrospective cohort study of nitinol stent implantation in patients at high risk for restenosis owing to long-segment (> or =10 cm) femoropopliteal disease.

METHODS

Sixty-five consecutive patients with peripheral artery disease underwent long-segment (> or =10 cm) femoropopliteal stent implantation using self-expanding nitinol stents after initial failure of plain balloon angioplasty (i.e., residual stenosis >30% or a flow-limiting dissection). Patients were followed for first occurrence of in-stent restenosis, defined as a >50% lumen diameter reduction by color-coded duplex sonography, with angiographic confirmation.

RESULTS

Cumulative median length of the stented segments was 16 cm (interquartile range [IQR] 12-25, absolute range 10-40) using up to 5 overlapping stents. During the median 8-month follow-up (IQR 6-11), no early thrombotic reocclusions occurred within 30 days, but 26 (40%) patients developed an in-stent restenosis. Cumulative freedom from restenosis at 6 and 12 months was 79% and 54% overall, respectively; at the same time periods, the rates were 84% and 71% in nondiabetic patients (n=41) versus 68% and 22% in diabetics (n=24) (adjusted hazard ratio 3.8, p=0.01). Cumulative stent length and number of implanted stents were not associated with restenosis.

CONCLUSION

Midterm restenosis after long-segment femoropopliteal stenting using self-expanding nitinol stents remains a major problem, particularly in patients with diabetes mellitus. The midterm results in nondiabetics are encouraging.