What l the future will bring to the fight of PAD is difficult to predict. However, I’m convinced that because all the cardiovascular communities, including vascular surgeons, angiologists, cardiologists and radiologists, are now working together in the development of new techniques and devices and especially thanks to the financial support of the industry by performing multicenter prospective highly scientific trials, the future of PAD patients will be bright.
One of the keys of success will be based on the scientific evidence that a specific
revascularization procedure with a specific dedicated device will first not harm the patient, second will be associated with a technical/clinical success rates high enough to counterbalance the inherent procedural/device related complication rates, and finally will be associated with acceptable long-term patients’ outcomes. In this modern era, where every new medical device is tried to be put on the marketplace as soon as possible, should warn every interventionists to be cautious on trying new
“sophisticated” procedure/device in clinical settings before robust evidence of safety and efficacy is available (337, 338). For that reason, teaching hospitals and some pioneering cardiovascular centers must concentrate their effort on producing high level scientific trials, in order to facilitate the
governmental institutions towards the final acceptance of these new endovascular procedure/devices (337, 338).
If one considers that the number of patients suffering from atherosclerosis remains stable in the last decades, the main effort which the cardiovascular community has to perform in the upcoming years will be mostly to improve all the revascularization procedures in terms of safety, immediate and long-term efficacy and especially in terms of minimal-invasiveness (i.e. endovascular), in order to allow more and more patients to benefit (even in an ambulatory setting) from the most adapted
revascularization procedure, which will finally probably improve the quality of life and hopefully also the amputation-free survival (Figure 68) (339).
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Figure 68: Trends in Lower Extremity Disease in the United States [reproduced from Hong MS et al. (339)]
Concerning the aortoiliac diseases the endovascular results already achievable with the present technologies (i.e., balloon angioplasty + stenting) are good enough, so no dramatic improvements are to be awaited in the upcoming years.
Conversely, at the femoropopliteal level, after many years where balloon angioplasty with a bailout stenting approach was the only available technology, thanks to the arrival and especially the combination of different techniques and devices, a lot of improvements will be observable in a near future. Accordingly, despite the initial encouraging results of the second generation femoral paclitaxel eluting stents, the future of femoropopliteal diseases will not be the stent. Indeed, stents, with their metallic components, disrupt the complex physiology of the femoral artery, suggesting that probably a stent-less solution will be more suitable for this delicate region. So far, absorbable femoral stents are at the very beginning of their development, while paclitaxel-eluting balloons, maybe in combination with some debulking pre-treatment (e.g., directional atherectomy), are already used in daily practice, with several promising trials evaluating the combination of these technologies actually ongoing.
At the infrapopliteal level, there is already a clear consensus that stents should be used strictly as a bailout situation, especially because the main advantage brought by stents (especially DES) in BTK vessels is related to a better patency rate, with no significant advantages in terms of limb salvages of these elderly and sick patients. Once dedicated BTK drug-eluting balloons are less expensive, probably this kind of technology will become the first line treatment of every CLI patient.
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10.0 CONCLUSIONS
The medical approach of patients presenting with a PAD is firstly associated with the optimal management of the cardiovascular risk factors, in order to significantly decrease the cardiovascular and cerebrovascular related mortality rate.
This medical approach should include at least one antiplatelet medication (e.g. Aspirin), a lipid lowering drug (e.g. statine) and an ACE-inhibitor regimen. Once this medical step is optimalized, but the patient still remains symptomatic, the need for a more invasive treatment may be considered. The type of an arterial revascularization (i.e. endovascular vs. surgical) should be evaluated according to the clinical scenario (claudication vs. CLI, vs. ALI), the disease extension, the patient’s co-morbidities and last but not least the local expertise.
10.1 CLAUDICATION
Concerning claudicant patients, the indications for endovascular therapy have gradually expanded over the last two decades. While discrete stenosis may be easily treated, the endovascular management of long total occlusions or advanced disease remains challenging. Depending on the localization and type of the lesion, as well as the anatomy of the diseased vessels, different access techniques may be chosen. The retrograde CFA approach ± crossover maneuver, is the easiest and least traumatic and leads to success in the majority of patients.
Regarding stent type, the high radial strength of balloon-expandable stents and the lack of foreshortening make them suitable in particular for ostial or severely calcified iliac lesions. The greater flexibility and conformability of self-expanding stents apply well to long lesions in tortuous ilio-femoro-popliteal segments. With respect to CFA interventions, stenting should be avoided whenever possible, in order to prevent crushing and to preserve future vascular access.
Based on the low incidence of major complications as well as good long-term results, percutaneous revascularization has replaced surgery for most of the lower limb occlusive conditions.
According to the TASC II recommendations, TASC II A-B lesions should be managed percutaneously, TASC II C lesions should be treated percutaneously or surgically according to the anatomical characteristics and the local expertise, and TASC II D should be reserved for a surgical management.
Thanks to improvements in the equipment and in the expertise of the interventionists recent reports suggest that also TASC II D lesions may be safely and efficaciously treated with an endovascular approach.
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Accordingly, this was further emphasized by the very recently published Guidelines of the European Society of Cardiology (340). Indeed, in these recent Guidelines one of the major modifications compared to the 2007 TASC II Guidelines, was that concerning the first revascularization option in case of complex lesions (i.e., TASC II C-D). The ESC Guidelines recommend that TASC II C lesions should be preferentially treated by an endovascular option first and managed surgically only in case of an endovascular failure or in case of recurrences. While TASC II D lesions remain a surgical domain, the ESC Guidelines stressed the importance that even such complex lesions may be approached by experienced interventionists in dedicated endovascular centers with a percutaneous attempt first. This minimally invasive approach may be nowadays attempted as first-line treatment, because of the good technical success rate achievable also in TASC II D lesions, the acceptable medium-long term patency rate and especially because patients presenting with TASC II D lesions are more and more elderly (i.e., >80 years old), with more and more associated severe co-morbidities (e.g., cardiovascular, pulmonary).
10.2 CRITICAL LIMB ISCHEMIA AND BTK INTERVENTIONS
The endovascular infra-popliteal interventions are usually performed in patients presenting CLI.
This type of intervention may be attempted in case of an isolated BTK disease or after a previously performed femoro-popliteal revascularization procedure (surgical or endovascular).
Patients presenting with a CLI are very often very elderly, severely diseased in term of BTK vessel occlusions, as well as in terms of impaired general conditions.
In case of CLI, the clinical success is much more important than the immediate or longterm angiographic result, because ulcer healing and limb salvage and not the vessel patency should be the main goal of every BTK intervention. Despite the number of the published trials randomizing different devises or techniques is still weak, the preliminary results of the reported retrospective and
prospective studies are very promising, with a limb salvage rate of almost 90% at one year.
Because the BTK endovascular approach is associated with a far below complication rate than what reported with a femoro-tibial bypass, this less invasive alternative should be proposed as first line treatment in any case where the main vascular problem is located at the level of the infra-popliteal region. Furthermore, if performed with caution, even an endovascular failure, does not compromise a future surgical limb-salvage intervention, which may be postponed until all endovascular options (e.g.
antegrade, retrograde, trans-collateral, etc) were attempted.