Percutaneous atherectomy in iliac, femoral and popliteal arteries

Catheter based interventions for lower extremity peripheral artery disease

The field of peripheral arterial intervention has exploded over the past 20 years. Current knowledge includes a growing evidence base for treatment as well as a myriad of new interventional approaches to complex disease. This review seeks to outline the current state of the art for interventional approaches to lower extremity peripheral arterial disease.

An update on vessel preparation in lower limb arterial intervention

Background

Plain balloon angioplasty has traditionally been used to treat lower limb arterial disease but can be limited by significant residual stenosis, vessel recoil, dissection, and by late restenosis. Appropriate vessel preparation may significantly improve short and long-term outcomes. We aim to give an overview of some of the devices currently available, or under investigation, for vessel preparation in the lower limb.

Main text

Vessel preparation devices include those that remove plaque (atherectomy devices) and those that modify plaque.

The four groups of plaque removing atherectomy devices are defined by their plaque removal method: Directional, rotational orbital and excimer laser are categories of devices investigated for plaque modification.

Intravascular lithotripsy devices generate sonic pulsatile pressure waves that pass into the vessel wall cracking calcified plaques whilst sparing soft tissue. This enables dilatation of calcified lesions at low pressure by conventional balloons and enables full stent expansion.

Other balloon based vessel preparation devices were designed to modify plaque and produce more controlled, lower pressure luminal expansion without major dissections and potentially with less recoil than conventional angioplasty balloons. Scoring balloons have a helical nitinol element attached to the balloon that scores plaque facilitating uniform luminal enlargement. Further specialty balloons have been developed in recent years, including the Chocolate, Phoenix and Serranator balloons. Finally, the temporary Spur self-expanding retrievable nitinol stent has a series of radially aligned spurs that are driven into the vessel wall by post-dilatation, potentially improving drug delivery.

Conclusion

Lesion specific vessel preparation aims to improve both short and long term outcomes through improved penetration of anti-proliferative drug, maximising luminal gain, reducing the need for stent placement and minimising intimal injury. Some forms of vessel preparation appear to improve short term outcomes; long-term outcomes remain uncertain. An overview of some of the multiple devices available for vessel preparation is presented.

Infrainguinal Arterial Intervention: Is There a Role for an Atherectomy Device?

Excision of atheromatous plaque is an attractive option for the minimally invasive treatment of peripheral arterial disease. Approved for use in 2003, the SilverHawk Plaque Exicison System (FoxHollow Technologies, Redwood City, CA) is a catheter-based plaque excision device allowing percutaneous removal of atheromatous material. This device represents the most recent generation of atherectomy tools. Overall experience with plaque debulking in the peripheral arteries spans almost two decades, and understanding of the technique continues to evolve. This article reviews the technology, current practices, and data on plaque excision.

[Percutaneous mechanical atherectomy for treatment of peripheral arterial occlusive disease]

Peripheral arterial occlusive disease (PAOD) is still an extremely important politico-economic disease. Diverse treatment procedures exist but the pillars of therapy are changes in lifestyle, such as nicotine abstinence and walking exercise as well as drug therapy. Further therapy options are considered after conventional procedures have been exhausted. These further options consist of improvement of the blood supply by surgical or minimally invasive procedures. The latter therapy options include balloon dilatation and stenting as the most widely used techniques. More recent techniques also used are cryoplasty, laser angioplasty, drug-coated stents or balloons as well as brachytherapy or atherectomy, whereby this list makes no claims to completeness. The multitude of different treatment methods emphatically underlines the fact that no resounding success can be achieved with one single method. The long-term results of both balloon dilatation and stenting techniques show a need for improvement, which elicited the search for additional methods for the treatment of PAOD. Atherectomy represents such an alternative method for treatment of PAOD. Basically, the term atherectomy means the removal of atheroma tissue. For percutaneous atherectomy, in contrast to surgical procedures, it is not necessary to create surgically access to the vessel but accomplishes the atherectomy by means of dedicated systems via a minimally invasive access. There are two basic forms of mechanical atherectomy: directional and rotational systems.

Percutaneous transluminal atherectomy: preliminary results

Percutaneous transluminal atherectomy with the Simpson atherectomy catheter was performed in 10 patients with 14 severe atheromatous stenoses of the femoropopliteal arteries. Removal of plaque material with restoration of vessel patency was successful in all patients without complication. Further clinical follow-up will have to determine whether the recurrence rate of stenoses will be lower with this method than with conventional balloon angioplasty.

Cell constitution and characteristics of human atherosclerotic plaques selectively removed by percutaneous atherectomy

The Simpson atherectomy device used for the recanalization of severely stenosed peripheral arteries is able to collect plaque material which can be further characterized. This study reports histological, immunohistochemical and transmission electron microscopic findings on advanced human primary atherosclerotic plaques of peripheral arteries percutaneously removed by a Simpson atherectomy catheter. Material from stenosing plaques consisted of dense connective tissue with abundant amounts of concentrically arranged elastic fibers and lamellae. This meshwork contained numerous cells, often arranged in clusters and oriented with their longer axis parallel to the direction of blood flow. The vast majority of these cells could be easily identified as vimentin-positive and desmin-negative smooth muscle cells containing lipid deposits in the perinuclear region and numerous glycogen particles. Monocytes/macrophages were observed only very infrequently. Plaque tissue contained a range of smooth muscle cell phenotypes. Most of the cells were of an intermediate phenotype, i.e. sparsely filled with myofilament bundles at the cell periphery and a high amount of organelles such as mitochondria, rough endoplasmic reticulum and Golgi cisterns. An intact lining of pieces of intimal tissue with endothelial cells was not observed. Two-dimensional gel electrophoresis of plaque tissue showed the presence of alpha-, beta- and gamma-actin isoforms with a clear predominance of the beta-isoform.

"Crackers, breakers, stretchers, drillers, scrapers, shavers, burners, welders and melters"--the future treatment of atherosclerotic coronary artery disease? A clinical-morphologic assessment

Although various public health preventive efforts and prescribed pharmacologic treatment methods will have long-term benefits in the reduction of coronary artery atherosclerosis and subsequent cardiac events, the immediate and short-term future in the treatment of coronary artery disease will focus on several interventional devices designed to remodel or remove causes of acute and chronic coronary artery obstruction. Certain clinical-morphologic aspects of these interventional devices or techniques that result in remodeling of the coronary lumen shape (balloon angioplasty, thermal probes, intravascular stents) or removal of obstructing material (lasers, atherectomy devices) are reviewed. Two new areas in the pathology of atherosclerotic plaque (plaque fissures, eccentric plaque) and their clinical relevance in coronary heart disease are described.

Percutaneous removal of atheromatous plaques in peripheral arteries

The peripheral Simpson "atherectomy" catheter was used to treat 21 patients with a total of 41 stenotic lesions (5 iliac, 35 superficial femoral, and 1 popliteal). 4 lesions were totally occluded and 16 (39%) were calcified. The mean (SD) degree of obstruction was reduced from 82.7 (14) to 21 (16)% (p less than 0.0001). Mean (SD) standardised walking distance increased from 79.9 (71.9) to 152.6 (89.7) m (p less than 0.0001); doppler index improved from 0.58 (SD 0.17) to 0.81 (0.16) (p less than 0.0001); performance on bicycle stress test rose from 276.3 (range 1-1100) to 584.8 (2-2250) watt-min; and index for 201Tl-scintigraphy of the lower leg increased from 0.68 (0.28) to 0.91 (0.36) (p less than 0.02). The improvement has been maintained for 6 months, the degree of stenosis on repeat angiography at 2-6 months (n = 14 lesions) being 20.7 (SD 13.7)% (unchanged from early post-treatment values). The only restenosis has been corrected by a repeat of the percutaneous procedure.