According to a presentation by Dr Jos C. van den Berg, Head of the Service of Interventional Radiology, Ospedale Regionale di Lugano, Switzerland, the soon to be published Transatlantic Inter-Society Consensus (TASC) 2006 recommendations will reflect the latest developments in technology and techniques in the endovascular approach to lesions of the superficial femoral artery (SFA).
Speaking at the recent MEET (Multidisciplinary European Endovascular Therapy) 2006 conference in Cannes, van den Berg stated, “The endovascular treatment of stenotic and occlusive disease of the superficial femoral artery (SFA) remains one of biggest challenges in current vascular practice,” citing that percutaneous transluminal angioplasty (PTA) of lesions of the SFA has a primary technical success rate that varies from 70 up to 90%, with the overall cumulative five-year primary patency rate ranging from 45 to 60%.
According to van den Berg, the most important factor negatively affecting the outcome of PTA of the SFA is the length of the stenotic or occluded segment. Indeed, lesions with a length of more than 10cm have a significantly worse outcome compared to shorter lesions, with a disappointing six-month patency of only 23%. Other factors related with unfavourable outcome include the presence of a high Fontaine classification and the presence of diabetes mellitus.
Several techniques have been studied in recent years, including laser-assisted PTA as well as additional stent-placement, to overcome the technical problems as well as the occurrence of restenosis. Although it has been demonstrated by several (randomised) studies, using ‘old’ stent technology that stenting leads to a higher initial success, long-term results are similar or even worse for SFA stenting, claimed van den Berg.
He said that based on these data, the 2000 TASC guidelines and classification recommended endovascular treatment in patients presenting with type A lesions, and depending on operating skills and preference also for type B/C lesions. Furthermore, surgical treatment was recommended in all type D lesions (Table 1), with no recommendations on the use of stents in the SFA territory made. In addition, guidelines from the CIRSE regarding use of stents in the SFA state that there is no place for primary stenting in the SFA and that use of stents should be restricted to patients with insufficient angiographic result after PTA (residual stenosis due to elastic recoil), or flow-limiting dissection at the PTA-site (se Table 1).
He also cited the SIROlimus Coated Cordis SMART Nitinol Self-expandable Stent for the Treatment of Obstructive Superficial Femoral Artery Disease (SIROCCO) trial that evaluated the impact on outcome using drug-eluting nitinol stents. The results showed that in the ‘bare-stent’ group (using uncoated nitinol stents) results at six and 18 months were comparable, with high patency rates, in both groups. In addition, van den Berg cited several other (mainly retrospective) studies evaluating mid- and long-term results, which confirmed the better results with ‘new’ stent technology. Indeed, the preliminary data from several randomised trials that are still enrolling seem to confirm the trend to better outcome using nitinol stent technology, even when treating longer and more complex lesions primary patency at one-year of up to 80% have been reported.
In addition, van den Berg announced data from the Randomized Study Comparing the Edwards Self-ExpandIng LifeStent vs. Angioplasty-alone In LEsions INvolving The superficial femoral artery or proximal popliteal artery (RESILIENT) trial, a multi-centre, prospective, randomised trial concerning balloon angioplasty to stenting for SFA and proximal popliteal artery disease using the Lifestent NT (Edwards Lifesciences). The trial includes 20-patient roll-in phase and a pivotal 206-patient randomised trial in which there is a 2:1 randomisation between stenting and balloon angioplasty. The primary endpoints of the pivotal trial are target lesion revascularisation at 12 months postprocedure. Secondary endpoints include primary and secondary patency at six and 12 months (determined by Duplex ultrasound), the usual measures of acute success and quality of life. The mean lesion length of the patients treated in the pivotal trial was 83.7mm (+28.6). Five patients had total occlusions, the mean number of stents placed per treated vessel was 1.8. The results at 30 days showed significant improvement in the ankle-brachial index (ABI) from baseline (0.76 to 0.97).
At six months of follow-up, the ABI was well maintained at 0.93 and all patients had improvement in at least one Rutherford category. There were no target vessel or target lesion revascularisations and no stent fractures were identified. The duplex primary patency at six months was 93.3%. The majority of these patients (18/20) have been reviewed out to 12 months: ABI is fairly well maintained 0.86 and 94.4% of patients have improved in at least one Rutherford category. There have been some target lesion revascularisation (10% at 12 months), with a primary clinical patency 90%. At 12 months, there have been no stent fractures in 17 patients available for follow-up (15).
According to van den Berg, it is
outcomes such as these as well as technological developments and improvements in techniques that will be reflected in the new TASC 2006 guidelines. “Furthermore, morphological stratification and recommendations are likely to be changed towards a more endovascular approach of lesions of the SFA,” van den Berg concluded.