Percutaneous Revascularization for SFA/Popliteal Arterial Disease: When and Why

In our experience, the “when” occurred in the late 1990’s for the CLI subset of SFA/popliteal disease (in our experience, 40-50% of CLI patients will have SFA/popliteal involved and 30-40% in LACI trial) and the “when” began a year or so ago for the truly lifestyle-limiting claudicatant who has failed aggressive “medical intervention.” In each subset, endovascular SFA/popliteal therapy (ESPT) has become more truly competitive with the evolution of improved endovascular tools. Long ago, I became lucky enough to be able to wear both the surgeon’s and interventionalist’s “hat” and I have experienced the limitations, advantages and complications of both femoral bypass surgery (FBS) and ESPT. It is clear to me that these treatments are not mutually exclusive, can be and are competitive, but one should not “replace” the other and they can be utilized creatively in a hybrid fashion to improve clinical outcomes, especially in the CLI subset (Case 1). Interestingly, even though both FBS and ESPT have their recognized advantages, disadvantages and limitations, both therapies need to continue to evolve and improve, because paradoxically when FBS fails, there oftentimes is an endovascular solution. Likewise, when ESPT ultimately fails, a surgical solution is often available as the solution to the patient’s problem. It is uncanny how both therapies now have very similar failure (restenosis) modes and rates at 2 and 5 years, and both require an approximately 20-30% reintervention rate at about 24 months to achieve desired outcomes (secondary successes). When at the bedside and forced to make a clinical decision between FBS and ESPT, in general, an “interventional-first approach” has been our policy. We believe it is justified by strict adherence to the following: 1. ESPT must never take away the patient’s (not the surgeon’s) surgical option. Therefore, the interventionalists must acquire basic knowledge about FBS to avoid inappropriate interventions at strategic surgical sites, targets, etc. 2. ESPT should never expose the patient to greater overall risks than FBS. A well-planned interventional strategy is paramount with limitations and boundaries set to minimize and avoid major complications (major distal dissections or embolization, vessel rupture, etc.). It is very important to learn how to “stop and not hurt the patient” and this only comes with experience. 3. Make sure the patient has the appropriate indication and let the patient make the final decision after presenting unbiased pros and cons regarding FBS and ESPT. I’ve found few patients will choose any surgical procedure over a percutaneous, less invasive alternative even if told to accept a higher likelihood of requiring repeat percutaneous procedures and not taking away their surgical option. The “how” part of the question continues to evolve and change, but in general, ESPT continues to improve. Slowly, data is beginning to appear to support ESPT position as “true competition” versus FBS. Even with the recent questions regarding nitinol stents (SIROCCO 24-month data and concerns about “stent fracture”), the experience of new non-stent technologies such as plaque excision, cryotherapy and larger excimer laser probes with improved adjunctive devices for crossing CTOs and re-entry catheters all hold tremendous potential to even further improve ESPT. Pharmacologic assistance (Angiomax, GP IIb/IIIa medications, statins) and risk factor modification will be of paramount importance and all are pros in favor of ESPT. In conclusion, considering ESPT improving data, the emergence of both improving stents and now even more promising non-stent debulking technologies, the nonsurgical approach to SFA-popliteal disease afforded the patient by ESPT, makes “now” as the time for ESPT to truly be competition as a first-line therapy for infrainguinal disease as long as one never jeopardizes the patient’s surgical option.

CIS Case: This case illustrates a hybrid, combined FBS and ESPT performed in the OR angiosuite. This “stent-through-graft” technique allows simultaneous classical surgical and endovascular therapies used in a creative fashion to improve patient outcomes. The graft is used as endovascular access and any endovascular therapy can be used (laser, stent, plaque excision, etc.) for more distal, as in this case, or proximal interventions. -- David E. Allie, MD Director of Cardiothoracic and Endovascular Surgery; Director of Noninvasive Vascular Labs Cardiovascular Institute of the South/Lafayette, Lafayette, LA david.allie@cardio.com

Endovascular techniques already are truly competitive with bypass surgery. Clearly there is a spectrum of disease severity in the femoropopliteal region, and that spectrum impacts what should be considered as the most appropriate therapy. At one end of the spectrum is the simple adductor canal stenosis. Assuming that this is in the setting of symptoms of significant claudication, it is hard to make an argument for any treatment other than endovascular therapy. At the opposite end of the spectrum is the patient with diffuse disease, such as occlusion from the origin of the superficial femoral artery extending well into the popliteal artery. While such disease may be amenable to percutaneous treatment, not many interventionalists are enthusiastic about stenting such advanced disease. If indicated, femoropopliteal bypass may well be the better option. The two major limitations of endovascular therapy, namely the occasional failure to cross an occlusion and the common event of restenosis, are being vigorously addressed. The extent to which these efforts meet with success will determine how much further endovascular therapy will chip away at the role of bypass operations. -- Mark W. Burket, MD Interventional Cardiology, Medical College of Ohio, Toledo, OH mburket@mco.edu

The choice of therapy of femoropopliteal arterial disease depends on the clinical presentation of the patient. Symptomatic claudicants in the Rutherford-Baker classification Class 1 and 2 have no major life-style limitations and certainly deserve a conservative trial with pharmacologic therapy (statins, clopidogrel and cilostazol) and a supervised exercise program. Currently, we have no convincing data that shows that surgical or percutaneous therapy alters the natural history of peripheral vascular disease in these patients and therefore a conservative approach is warranted. We believe that claudicants with advanced symptoms (Rutherford-Baker Class 3, i.e. with marked limitation of ordinary physical activities) and TransAtlantic Inter-Society consensus (TASC) A to C lesions are good candidates for percutaneous interventional therapy in addition to risk factors modifications. In these patients complication rates appear to be very small with very low mortality and limb loss and functional improvement is quickly noticeable. In our experience, conservative therapy alone in these patients, although might offer some improvement in symptoms, it is generally not enough for the majority of these patients to achieve their desired goals for activity level. Patients, however, need to be well informed that the choice of angioplasty could mean an approximate 50% chance of returning back to the endovascular laboratory for retreatment of restenosis and in order to sustain a long-term clinical success. The surgical choice in these patients appears to offer similar long-term results to percutaneous angioplasty with less repeat revascularization at the expense of high initial mortality and morbidity rates. When my patients are faced with these options, their choice of percutaneous intervention is almost predictable. Severe claudicants with TASC D lesions are clearly a challenge to the inteventionalists. Although the traditional approach to treat these patients has been surgical, recent data from our group presented at ACC 2004,¹ showed that the acute success of the procedure is achievable in 90.2% of the cases with a subsequent clinically driven target lesion revascularization rate of 11.8% at 12 months. The Walking Impairment Questionnaire was used to assess quality of life pre and post procedure, and it was markedly improved with revascularization at a mean follow-up of 374 +/- 321 days. More data are needed in this group of patients to decide on the best course of therapy. At our institute, we currently attempt percutaneous intervention on these patients with intense subsequent follow-up with ankle-brachial indices (ABIs) and for recurrence of symptoms. Surgery is reserved for those who fail percutaneous or conservative therapy. Rest ischemia patients (Rutherford-Baker Class 4-5) are a high-risk population for complications following revascularization, whether percutaneous or surgical. Mortality, limb loss, acute thrombosis, urgent salvage revascularization, myocardial infarction and other serious complications are not uncommon in this group of patients with revascularization. This group of patients typically presents itself with significant below the knee disease and poor runoffs, but more often has multiple level arterial disease that frequently involves the femoropopliteal vessels. Percutaneous intervention for critical limb ischemia of femoropopliteal vessels is increasingly replacing bypass surgery without compromising “primary patency, limb salvage, patient survival, or subsequent vascular intervention”.^2-3 Percutaneous treatment of SFA/ popliteal disease in the limb ischemia patient can have potentially several advantages. This includes alleviating limb ischemia with or without the presence of infrapopliteal disease by enhancing forward flow to the lower extremity. Also, it can be the treatment of choice in certain patient subgroups such as poor surgical candidates, or as a palliative measure in those with reduced life expectancy. Furthermore, it might reduce the need for a femoral-popliteal bypass surgery and will lead to a better visualization of the tibial vessels facilitating the selection of the best method to treat them (surgical or percutaneous). Although long-term patency of percutaneous therapy is again challenged with surgery, we believe close monitoring of these patients (objectively and clinically), with a low threshold to reintervene if necessary, maintains long term overall clinical success and reduce the need for bypass surgery. Recent data by Anderson et al.⁴ showed that endovascular therapies have increased by 979% since 1995. The recent widespread acceptance of percutaneous interventions for treating peripheral vascular disease has reduced the role of surgery as a first line therapy irrespective of lesion characteristics. At our Institute, we adopted an aggressive risk factors modification approach coupled with endovascular therapy in the very symptomatic patients irrespective of lesion classification.-- Nicolas W. Shammas, MS, MD Genesis Heart Institute, Cardiovascular Medicine, PC Davenport, IA shammas@mchsi.com

I certainly agree that medical therapy and pharmacologic intervention — together with smoking cessation and exercise — deserve a much greater emphasis as they are likely to result in significant clinical benefit. I would also agree with the view that “... a percutaneous approach should be the first line of therapy.” The reality, though, is that in most communities around the country surgical revascularization and “conservative” (essentially, “no treatment”) management remain the most frequently used options. The fact is that most patients with femoro-popliteal disease presenting with significant symptoms are found to have extensive occlusions. While technically feasibly for an elite group of advanced, aggressive interventionists, most vascular physicians are unwilling or unable to attempt such “daring procedures” in the face of long occlusions, especially those that are “flush” with the common femoral artery — without a patent proximal SFA segment. This is based on technical as well as technological limitations. With few exceptions, long occlusions are difficult to recanalize for the average-experience catheter interventionist, and the achievement of durable patency is even more uncertain. Surgical bypass, on the other hand, is not without problems — mainly, major morbidity and occasional mortality. Nevertheless, predictable and durable revascularization can be achieved when a good target distal vessel is available — and demonstrable in the vast majority of such patients. Furthermore, such operations are within the domain of the “average” vascular surgeon... Percutaneous techniques have much to offer, but they have significant limitations in the hands of most interventional physicians. Progress in these areas will come in the future through new technologies, better devices, and an evolving mindset that will enable the undertaking of nonsurgical procedures for treatment of patients with significant ischemia as a result of occlusive disease in the femoro-popliteal territory. -- Frank J. Criado, MD Director, Center for Vascular Intervention; Chief, Division of Vascular Surgery, Union Memorial Hospital/MedStar Health Baltimore, MD frank.criado@medstar.net

Femoro-popliteal artery endovascular therapy remains a major challenge for the practicing interventionist. However, I would challenge the question to include “optimal medical therapy.” After all, isolated superficial femoral artery disease rarely results in critical limb ischemia. The majority of these patients have intermittent claudication, where the natural history of progressive limb ischemia and limb loss is quite low and favorable for the patient. Therefore, surgical revascularization must remain an option reserved for patients who cannot perform their required/desired activities due to lifestyle-interfering claudication. Aggressive risk factor interventions (including lipid lowering, which not only reduces risk of myocardial infarction/stroke, but may also result in improved walking distances), supervised exercise, and pharmacotherapy (limited in the US to cilostazol) often result in sufficient clinical improvement for many patients. Due to current limitations of endovascular technology (despite low procedural complications and excellent acute symptomatic improvement), lack of durable symptomatic benefit prevents this option from being viewed as first-line therapy. Perhaps drug elution, with pre-stent plaque treatment (laser, debulking, cryotherapy, radiation) will result in longer term patency rates and, most importantly, improvement in quality of life. -- Michael R. Jaff, DO Medical Director, Vascular Ultrasound Core Laboratory Massachusetts General Hospital Boston, MA docmrjaff@aol.com

The time is now. Whether the desired therapeutic result is significantly improved ambulation or limb salvage, percutaneous intervention allows for the safest effective treatment. The IntraCoil trial was associated with only a 1.5% complication rate and no amputations. Over 85% of the patients that received stents improving their functional class by at least one grade. This is in contrast to cilostazol, which is effective in approximately 1/2 of patients but with approximately 20% of the patients not tolerating customary dosing. With the latest SIROCCO data on the bare metal stents showing 2-year patencies similar to surgical PTFE grafting, it is evident that limb salvage can be also be more safely and effectively achieved with a percutaneous approach. Even if restenosis does occur, patency can be easily achieved, again usually as an outpatient. When one has to compare the zero mortality and almost nonexistent infection risk of endovascular treatment with surgical rates of up to 3% for mortality, as well as significant infections in up to 30% of patients, the choice is certainly becoming clearer that a percutaneous approach should be the first-line therapy. -- Gary M. Ansel, MD Mid Ohio Cardiology Consultants Columbus, OH gansel@mocvc.com

In the management of a patient with infrainguinal occlusive disease, two prime issues to be considered are: indication for revascularization (lifestyle-limiting claudication versus limb salvage)and status of inflow-outflow circulation. The current endovascular technology allows us to achieve procedural success in most patients, including long total occlusions, with low and acceptable complication rate. Additionally, inflow can almost always be improved, when aorto-iliac occlusive disease coexists, with high success rate. Therefore, endovascular therapy should, at present, be considered first-line therapy in claudicants, even if secondary intervention is required in some cases to maintain long term patency. In cases of limb threatening ischemia, in a large proportion of cases, straight line flow can be restored, allowing adequate perfusion and healing of ulcers and avoidance of amputation. Endovascular therapy should be the first-line therapy in such cases. In my opinion, only those cases where limb is threatened and endovascular techniques currently available do not allow restoration of straight line flow should be subjected to bypass surgery. The nitinol stents (and drug elution in near future) allow longer patency even in femoro-popliteal segments. The importance of medical therapy with statins, anti-platelet agents and supervised walking program cannot be stressed enough, and should be used as an adjunct. Of note, poor outflow (below-the-knee occlusive disease) is a poor prognostic marker regardless of mode of revascularization. -- Sandeep Khosla, MD Chief, Cardiology; Director, Endovascular Therapeutics Mount Sinai Hospital, Chicago, lL khos@sinai.org