mapping modality,31 this use requires a highly dedicated vascular laboratory and to date has not gained

wide acceptance. CTA is increasingly being utilized as a preoperative road-mapping technique in

institutions able to provide high-quality three-dimensional reconstructions. MRA is also particularly

useful as a noninvasive screening test to determine the suitability for percutaneous therapy, as advances

have solved many of the technical limitations of earlier studies (Fig. 93.3). Should a lesion amenable to

percutaneous therapy be identified, angiography is then pursued. Alternatively, in some instances of

femoropopliteal reconstruction, operative planning may be based solely on MRA scanning if highquality time of flight and gadolinium-enhanced images are obtained.34–36 In many cases, however,

surgeons are reluctant to proceed to surgery without the confirmation of anatomy afforded by standard

contrast angiography. This reluctance is particularly true if the distal target is at the tibial or pedal

level, where anatomic detail provided by CTA and MRA remains more limited.37

When digital subtraction angiography is undertaken for preoperative planning, a retrograde femoral

approach is typically utilized from the contralateral limb. In general, a catheter is placed in the

infrarenal aorta to perform aortography and iliac angiography. If there is no aortoiliac disease which

precludes catheter traversal, the wire and catheter are utilized to go “up and over” the aortic bifurcation

to place the catheter in the common femoral artery of the affected limb. Lower extremity digital

subtraction angiography is then carried out. Selective catheterization of the affected limb via “up and

over” approach allows contrast volume to be minimized. It also allows the surgeon or interventionalist

to proceed immediately with infrainguinal endovascular intervention through a single vascular access

should endovascular therapy be the preferred treatment based on the patient’s presentation and

infrainguinal anatomy defined in the angiogram.33 In patients in whom noninvasive imaging indicates a

widely patent common femoral and proximal superficial femoral artery and body habitus is not

prohibitive, an antegrade approach can serve as useful alternative. In ambiguous lesions or when

iodinated contrast must be minimized, pull-back pressure measurements, both before and after the

administration of a systemic vasodilator such as papaverine or nitroglycerine or the application of a

tourniquet to induce reactive hyperemia, can be useful in documenting the hemodynamic significance of

a particular stenotic zone.38 The utilization of gadolinium or carbon dioxide as contrast agents in

patients with compromised renal function, although perhaps less effective in the periphery than in the

aortoiliac vasculature, can minimize or eliminate the nephrotoxic effects associated with standard

iodinated contrast medium.39,40

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Figure 93-3. Magnetic resonance angiogram identifying patent inflow vessels (A), short-segment occlusion of right superficial

femoral artery (B), and patent popliteal and tibial vessels (C and D), a lesion amenable to attempt at percutaneous therapy.

Medical Treatment

Risk factor modification remains a cornerstone of the management of lower extremity occlusive disease.

Smoking cessation has been shown to reduce the risk of disease progression, amputation, cardiovascular

mortality, and may lead to symptom relief in some patients. Smoking cessation has been best achieved

with repeated physician assistance, group counseling, nicotine replacement or nicotinic receptor

agonists, and antidepressant drug therapy in some patients. Weight and blood pressure reduction and

aggressive efforts at lipid control should be addressed with every patient with atherosclerotic disease.

Lipid-lowering therapy involves dietary modifications first and utilization of hydroxymethylglutaryl–

coenzyme A–reductase inhibitors (“statins”) to lower LDL cholesterol and fibrates or niacin to raise HDL

cholesterol. Patients with lower extremity occlusive disease should have a goal LDL cholesterol of <70

mg/dL.13 Statin therapy also has benefits in patients with PAD which are independent of their effect on

lipid reduction. Stains stabilize atherosclerotic plaque and reduce vascular inflammation. Statin therapy

has been shown to reduce cardiovascular events in patients with PAD.41,42 In addition, statin therapy is

associated with improved 1-year survival in patients undergoing lower extremity bypass for CLI.31

Patients with diabetes should have aggressive control of blood glucose toward a goal hemoglobin A1C

of <7%. Antiplatelet therapy in the form of either aspirin or clopidogrel is a critically important

element of the treatment of established occlusive disease, given its documented ability to prevent

thrombosis and embolization and possibly even to arrest the progression of atherosclerosis.43 Aspirin

and clopidogrel have both been shown to reduce cardiovascular morbidity and mortality in patients

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with PAD.44,45

Strong evidence exists supporting the benefit of a supervised, structured walking program in

increasing the walking distance of patients with claudication.46 The benefit of walking outside of a

structured regimen with close follow-up is more debatable.47 Nevertheless, patients should be

encouraged to “walk through” the onset of lower extremity pain, resting intermittently as required.

Overall, pharmacotherapy has not had a significant impact on relieving symptoms of infrainguinal

occlusive disease. There is some evidence to suggest cilastazol, a phosphodiesterase inhibitor, improves

walking distance and quality of life.48,49 While early studies showed that pentoxifylline, a rheologic

agent, had beneficial effects on walking distance, later studies have questioned its clinical benefit.50,51

Similarly, although older studies suggested that prostanoids improved healing of ischemic ulcers, the

current evidence does not support the utility of any systemic drug for the relief of ischemic rest pain or

the treatment of ischemic ulcerations.52–54

Indications for Revascularization

The two major indications for the intervention of infrainguinal arterial occlusive disease are lifestylelimiting claudication and CLI. Less common indications for infrainguinal arterial reconstruction include

trauma-related vessel disruption, popliteal artery entrapment syndrome, and femoropopliteal arterial

aneurysm with thromboembolism. Infrainguinal revascularization for the treatment of peripheral

vascular occlusive disease has been increasingly successful for both long-term palliation of IC and for

the preservation of limbs threatened by critical ischemia.

Critical ischemia is associated with inevitable amputation for most patients unless revascularization is

undertaken. Although there are certainly cases in which primary amputation represents the safest and

most advisable solution in the face of irreversible ischemia, particularly in nonambulatory patients or in

cases in which extensive infection or tissue necrosis is present, an attempt at revascularization is

generally indicated when a limb is threatened by severe ischemia. However, given the morbidity and

mortality associated with CLI, it is paramount to tailor therapy to an individual’s overall medical

condition and life expectancy as well as the patient’s goals of therapy. In the often frail CLI population,

postoperative outcomes are most strongly impacted by patients’ preoperative medical condition and

functional status.55 Nevertheless, improvements in endovascular technology and techniques as well as

perioperative management and surgical technique have allowed progressively more distal

revascularizations to be successfully completed in an older, sicker, and challenging patient population.

In general, high limb salvage (80% to 90%) rates may be anticipated for patients with critical ischemia

at institutions devoted to peripheral bypass surgery.56–58 In addition, occlusive disease of the tibial

vessels, once thought to be the exclusive domain of operative bypass, is increasingly being treated

percutaneously.59 Though the long-term durability of various endovascular revascularization approaches

is limited, similar rates of limb salvage from 1 to 3 years have been demonstrated.59–61

Claudication is a relative indication for intervention given the natural history of the disease, and it

remains a subjective assessment on the part of both patient and surgeon as to the relative degree of

disability a particular level of claudication pain represents. For example, two-block claudication in a

younger patient whose livelihood depends on walking tolerance constitutes a more significant disability

than the same degree of claudication in an older, retired individual able to attend to his or her daily

affairs without significant consequence. Thus, proximal above-knee surgical reconstruction in a patient

with disabling claudication and a patent popliteal artery with intact runoff may be justified in view of

its minimal operative mortality, excellent long-term palliation, and absence of added risk of limb loss

beyond that expected from the natural history of the disease process. Classically, it has been thought

that the benign natural history of claudication does not warrant aggressive femorotibial reconstruction

in patients with diffuse superficial femoropopliteal and tibioperoneal disease, though reconstruction will

often provide symptomatic benefit and can be considered in a good-risk patient.62

In recent years, the low morbidity of endovascular revascularization in combination with patient

desire for intervention seems to have lowered the threshold for offering catheter-based

revascularization for claudication. Patients once considered most appropriate for risk factor

modification, exercise therapy, and medical treatment are now increasingly being offered percutaneous

revascularization.63,64 Nevertheless, endovascular revascularization is not without risk and is at present

of limited durability. It is therefore prudent to follow the classical surgical axiom that because most

patients with claudication remain stable for years, it is important to allow sufficient time for collaterals

to develop and enlarge; some patients may improve to such an extent that intervention proves

unnecessary.19

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Approach to Revascularization

The last two decades have seen increasing utilization of endovascular revascularization of infrainguinal

occlusive disease.64 In this light, it cannot be overemphasized that symptom status and not anatomic

findings should serve as the basis for revascularization. Once the decision to intervene has been made, a

variety of factors should be considered in choosing whether to proceed with an endovascular, surgical,

or combined (hybrid) approach. The goals and outcomes of revascularization should be considered in

the context of the individual patient’s comorbidities, operative risk and overall life-expectancy, the

extent of the occlusive disease present, and the expected durability of the procedure.

Anatomic variables appear to be the key determinant of the success and durability of endovascular

therapy. With the promulgation of endovascular therapy has arisen, the need to classify the anatomic

severity of disease in order to guide potential therapy and compare outcomes between various modes of

revascularization. The Trans-Atlantic Intersociety Consensus Document on Management of Peripheral

Arterial Disease (TASC) was published as the result of a multidisciplinary collaboration between key

medical and surgical vascular societies in 2000 and an abbreviated update was published in 2007.14,65

This document classified infrainguinal occlusive lesions into classes A, B, C, and D based upon the

location of the lesion and the number, length, and severity of the stenoses and/or occlusions present.

Their recommendations, which reflect current practice to a variable extent, include initial endovascular

treatment for TASC A lesions, primary surgical treatment for TASC D lesions, and individualized

tailoring of treatment for TASC B and C lesions depending upon endovascular suitability and surgical

risk. While a complete description of this classification schema is beyond the scope of this chapter, a

few general principles are worth noting. The patency of endovascular revascularization decreases the

more distal the disease and is less in patients with stenoses that are multiple, longer, and more

severe.14,59,66 On the other hand, the success of open bypass surgery is largely dependent on the quality

conduit.67,68 Sustained hemodynamic improvement in the affected limb is the measure of effective

revascularization and the goal of therapy. Neither “endovascular first” nor “bypass first” approach can

be applied to all patients. Selection of the optimal revascularization strategy, at least in CLI, involves

assessment of life expectancy, surgical risk, the severity of tissue loss in the limb, the anatomic pattern

of disease, and the quality of vein available as a conduit for bypass. The complexity of decision-making

emphasizes the importance not only of interventional expertise, but of thorough training in vascular

disease and comprehensive experience in the care of vascular patients.69

Figure 93-4. Angiogram of the right superficial femoral artery demonstrating short-segment occlusion and more diffuse stenosis in

Hunter canal (A), which was treated with angioplasty and self-expanding bare metal stent placement (B).

Endovascular Therapy

A marked increase in the number and versatility of available balloons, stents, and other devices has

helped to fuel the increasing application of percutaneous technology. While a complete description of

endovascular treatment options and outcomes is beyond the scope of this chapter, a brief introduction is

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necessary. Percutaneous vascular intervention is generally performed under local anesthesia with

minimal intravenous sedation as either a day surgical procedure or involving an overnight admission.

Percutaneous vascular intervention first involves wires traversal of hemodynamically significant

stenosis or occlusions in the arterial tree. Dilatation of the lesion with percutaneous transluminal

angioplasty (PTA), with or without stenting, or obliteration of the lesion via atherectomy or other

modalities is utilized to reestablish blood flow through the diseased segment (Fig. 93-4). For

interventions on the femoropopliteal and tibial arteries, retrograde contralateral femoral access allows

angiography of the affected limb and establishment of a stable treatment platform via an “up and over”

approach across the aortic bifurcation. Ipsilateral antegrade femoral access can also be utilized. More

recently, retrograde ipsilateral pedal and tibial access has been described to allow wire traversal and

endovascular treatment of disease not amenable to the standard antegrade approach.70

Periprocedural outcomes with endovascular therapy are excellent. Technical success, which is

generally defined as the presence of antegrade flow through the tree to lesion with less than 30%

residual stenosis at the conclusion of the procedure, is reported at 80% to 95% for both femoropopliteal

and infrapopliteal procedures.59,71,72 Associated overall morbidity in recent reports ranges between 8%

and 17% while mortality is low at approximately 0.2%. Contrast-induced nephropathy remains a

common complication. With the development of hypoosmolar and isoosmolar contrast agents; the

overall incidence is approximately 8%, whereas the rate of acute renal failure requiring dialysis is less

than 1%.72–74 Higher rates are found in patients with pre-existing renal failure and diabetes.75,76

Substantial morbidity can result from access-site complications, predominantly pseudoaneurysms,

groin hematomas, and arteriovenous fistulas (AVFs), which occur in 1% to 4% of patients.72,77 Most of

them can be managed conservatively, with close observation, serial hematocrit checks, and fluid and

blood product replacement. Surgery is reserved for those patients with ongoing bleeding effecting

hemodynamic instability or distal ischemia, or pseudoaneurysms or AVFs that fail to resolve on serial

ultrasound imaging with several weeks of careful observation. Stable pseudoaneurysms in patients

without coagulopathy can also be managed with ultrasound-guided compression therapy or ultrasoundguided thrombin injection into the pseudoaneurysm sac to induce thrombosis.78 Infection related to the

placement of newer percutaneous closure devices utilized for puncture site control typically present

several weeks to months after the percutaneous procedure. Rarely, maldeployment of these devices can

lead to embolic or thrombotic sequelae causing compromise of distal flow.79

Reports indicate that endovascular therapy has good short-term efficacy for femoropopliteal disease

(Table 93-1). In claudicants, PTA for femoropopliteal lesions has generally yielded 1-year patency of

approximately 77% and 65% for stenoses and occlusions, respectively.66,80 In patients with CLI, PTA for

femoropopliteal lesions has yielded 1-year primary patency of 60% and 40% for stenoses and occlusions,

respectively.80 Review of the literature does not provide compelling evidence that stent placement

improves the results of all femoropopliteal PTA.60Many practitioners thus utilize stents selectively for

failure of PTA (defined as greater than 30% residual stenosis or flow limiting dissection) in

femoropopliteal lesions. However, there is strong evidence, including two randomized trials, that

primary self-expanding stent placement yields higher short-term patency than PTA and/or provisional

stenting for more advanced femoropopliteal lesions.80–82 Primary self-expanding stent placement is

therefore preferred over angioplasty alone for femoropopliteal occlusions and long-segment lesions by

most surgeons and interventionalists. Infrapopliteal disease appears less amenable to endovascular

therapy (Fig. 93-5). Primary patency is generally reported at 45% to 55% at 1 year.59,83 Patency does

not appear to be improved by stenting in the infrapopliteal segment.84,85

RESULTS

Table 93-1 Patency of Femoropopliteal Angioplasty and Stentinga

Lack of durability has been the Achilles heel of infrainguinal endovascular intervention. Three-year

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patency after PTA has generally been reported to be 43% to 61% and 30% to 48% for femoropopliteal

stenoses and occlusions, respectively.80 Five-year patency data are seldom reported but have been

generally reported to be between 26% and 45% after PTA for femoropopliteal lesions.14

There is a scarcity of high-level data comparing PTA and bypass surgery for infrainguinal occlusive

disease. Heterogeneous study populations and the lack of standardized methodology and endpoints have

limited the ability to compare the effectiveness of endovascular surgical therapy.86 In addition, there

have been only four randomized trials comparing angioplasty and lower extremity bypass surgery and

these have included a heterogeneous group of patients, measured different outcomes, and generally

included limited anatomic detail.87–90 Pooled analysis of these trials demonstrates that surgical bypass

generally had superior patency to PTA at 1 year, but there were no differences in progression to

amputation. The BASIL (Bypass vs. angioplasty in severe leg ischemia) trial which randomized 452

patients with “severe limb ischemia” to a “bypass first” or “balloon angioplasty” first strategy is the

most widely cited trial. There was no difference in the primary endpoint of amputation-free survival at

6 months, although a “surgery-first” strategy was associated with greater cost and morbidity.87 It is

necessary to note that the endovascular arm of this trial did not include adjunctive procedures such as

stenting which are now frequently utilized in current day practice. Upon long-term follow-up of at least

3 years and more than 5 years in the majority of patients, bypass was associated with improved overall

survival and a strong trend toward improved amputation-free survival in patients who survived at least

2 years. In addition, most balloon angioplasty patients ultimately required bypass surgery. Bypass after

failed balloon angioplasty had significantly worse patency than that of primary bypass.91 This finding

corroborated other reports demonstrating that surgical bypass after failed endovascular treatment is

inferior to primary bypass, indicating that a universal “endovascular first” approach may not be

appropriate as failed endovascular intervention may “burn bridges” for surgical revascularization.

Careful consideration must be given to the best initial therapy for infrainguinal occlusive disease.92

Figure 93-5. Angiogram of the tibial arteries showing diffuse anterior tibial artery high-grade stenosis (A) which was treated with

long-segment balloon angioplasty, (B) completion angiogram showed patent anterior tibial artery with no significant residual

stenosis (C).

7 8 For patients with favorable anatomy and significant operative risk, and for the treatment of

claudication in general, percutaneous therapy has assumed a primary initial role. When medical therapy

or percutaneous treatment has proven inadequate, open surgical revascularization remains the gold

standard for those patients with disabling claudication. Furthermore, until the efficacy and durability of

infrainguinal percutaneous intervention is better defined, surgical revascularization remains the gold

standard for any patient with CLI, especially those with extensive tissue loss. The relative roles of

surgical and percutaneous intervention are actively being refined. It nevertheless appears that the rising

popularity and success of femoral and tibial wire-based interventions may be reducing the volume, or

ultimately just delaying the timing of, subsequent infrainguinal reconstructive surgery. Furthermore,

many patients are best treated with a combination of percutaneous and open surgical therapy, often in a

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single procedure (hybrid procedure). In many instances, endovascular and open surgical

revascularization are thus complementary modes of therapy.

Operative Management

9 Successful infrainguinal arterial bypass requires sound planning as well as technical expertise. As such,

it remains the signature operation which distinguishes vascular surgeons from other specialists involved

in the treatment of PAD. Successful infrainguinal bypass grafting requires adequate arterial inflow.

While aortobifemoral, femorofemoral, and axillofemoral bypass grafting remain routinely performed

inflow procedures, aortoiliac angioplasty and stenting are increasingly becoming the preliminary

procedures performed to attain sufficient inflow prior to construction of a more distal bypass graft. At

times, the necessity of improving the inflow to support an infrainguinal graft is determined

intraoperatively, either by direct visual assessment of the arterial flow at the desired donor site or by

comparison of a transduced pressure tracing from the donor site with that of a systemic pressure

tracing, typically obtained from a radial arterial line. Of equal importance to the outcome of any

infrainguinal graft is target vessel selection. In general, the target vessel should be the least diseased

artery that is the dominant supply to the foot. If tissue necrosis is present, restoration of pulsatile flow

to the foot is often required to obtain full and sustained wound healing.

Infrainguinal surgical bypass can be performed under general anesthesia, or in the appropriate

patient, under regional, spinal, or epidural anesthesia. In cases involving multiple sites of dissection,

such as those necessitating more tedious arm vein or lesser saphenous vein harvesting, the procedures

are particularly amenable to a two-team approach, with the time saved having direct benefit in

minimizing the total anesthetic load and physiologic insult. The patient is sterilely prepped and draped

from the midabdomen down to the foot. It is our practice to work from proximal to distal, first

exploring the inflow artery and exposing the venous conduit. We then explore the site proposed for the

distal anastomosis, as high-quality preoperative imaging has already defined a suitable target vessel.

For patients with superficial femoral artery disease, the initial dissection is most commonly at the

level of the common femoral artery. This vessel is exposed through a longitudinal or oblique incision

centered directly over the femoral pulse. Lymphatic tissue overlying the femoral vessels is best ligated

and divided to prevent the postoperative development of lymph fistulas or lymphoceles. The severity of

any concomitant common femoral and profunda femoral disease and the level of reconstruction planned

dictate the extent of exposure of the femoral vessels. In most instances, the dissection extends from the

inguinal ligament to the common femoral artery bifurcation, where the origins of the superficial and

profunda femoral arteries are individually isolated.

Figure 93-6. In the setting of orificial profunda femoral artery disease, extending the common femoral arteriotomy into the origin

of the profunda and performing a profundaplasty will maximize profunda flow in the event of graft thrombosis.

If a profundaplasty is required, the dissection is extended distally along a sufficient length of the

profunda femoral artery to attain an endpoint suitable for clamping and sewing (Fig. 93-6). Similarly,

the inguinal ligament can be partially divided to facilitate access to the distal external iliac artery in

cases in which a more extensive proximal endarterectomy is necessary. In these circumstances, it is

customary to close the endarterectomized bed with a vein, bovine pericardial or Dacron patch, onto

which the proximal anastomosis can subsequently be attached.93 In patients with a hostile groin crease

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from prior surgery or radiation therapy or in obese, diabetic patients with an intertriginous rash at the

inguinal crease, meticulous skin preparation, close attention to draping, careful surgical technique, and

judicious use of a short course of intravenous antibiotic therapy help minimize the chances of a

postoperative wound or graft infection.

If all or part of the superficial femoral artery is spared of significant atherosclerotic involvement, the

proximal anastomosis can be moved distally as dictated by the particular anatomic pattern of disease,

and a so-called “distal origin graft” can be fashioned (Fig. 93-7).94 This situation is particularly

applicable to the diabetic population, in whom infrapopliteal disease is the rule and sparing of the

superficial femoral and popliteal arteries is not uncommon. It is also utilized in situations in which

conduit is sparse, and a moderately diseased proximal vessel is accepted as an inflow source for a more

distal origin bypass graft in the interests of performing a fully autologous vein graft rather than

utilizing prosthetic material. An increasingly popular approach when only limited conduit is available is

to combine, either concurrently in the operating room or as a staged preoperative procedure, catheterbased treatment of the superficial femoral or popliteal artery inflow with more distal bypass.95

The above-knee popliteal vessel is easily exposed through a medial thigh incision, with subsequent

posterolateral retraction of the sartorius muscle. The popliteal artery with its accompanying vein and

nerve is found just posterior to the femur. The vessel is palpated to determine the presence of

atherosclerotic plaque, which will guide the extent of dissection and the optimal bypass target site. The

below-knee popliteal artery is also exposed through a medial incision in the proximal calf (Fig. 93-8). If

the saphenous vein is to be harvested, the incision is made directly over the vein to minimize the

creation of devascularized skin flaps. With the exposed vein carefully protected, the incision is carried

through the deep muscular fascia and the medial head of the gastrocnemius is reflected posterolaterally

to expose the below-knee popliteal fossa. The distal popliteal artery is then dissected free from the

adjacent tibial nerve posteriorly and popliteal vein medially. If the distal target is the tibioperoneal

trunk, the dissection is continued along the anteromedial surface of the distal popliteal artery after

dividing the origin of the soleus muscle from the tibia (Fig. 93-9). In instances in which the below-knee

popliteal artery has previously been exposed or where sepsis is involved, a lateral approach with

excision of a segment of proximal fibula is a useful alternative approach to the below-knee popliteal

artery.

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