Historical Background
In 1964 Dotter and Judkins first reported percutaneous transluminal angioplasty as a technique for treating atherosclerotic stenoses and occlusions. Application of this method for the treatment of iliac occlusive disease was reported in 1974. In February 1974 Grüntzig and Hopff introduced the clinical use of a new balloon catheter, and in 1979 Grüntzig and Kumpe reported a 2-year patency rate of 87% for treatment of iliac lesions with this technique. In 1985 Tegtmeyer and colleagues first reported the two-balloon technique for angioplasty in the region of the aortic bifurcation, commonly called the “kissing balloon” technique. In 1987 Johnston and co-workers prospectively analyzed the results of 984 iliac angioplasties alone and noted an initial success rate of 88%, with continued success at 5 years of 48%. In 1992 Palmaz and associates reported the results of a multicenter trial of 486 patients with iliac artery disease treated with balloon-expandable stents. Initial success was achieved in 99% of patients, with continued success at 43 months of 68%. In 1995 long-term results for treatment of iliac lesions with self-expanding stents were reported. In 2004 the outcomes of iliac stenting using two different self-expanding stents were compared in a multicenter prospective randomized trial, with similar 1-year primary patency of greater than 90%. The role of primary iliac stenting or angioplasty with selective stenting was assessed in the Dutch Iliac Stent Trial Study, a prospective randomized, multicenter study. Similar outcomes were reported for both groups, with approximately 80% of treated iliac artery segments remaining free of repeat revascularization procedures at 5 years. In a recent systematic review of 19 nonrandomized cohort studies, 4-year primary patency for Trans-Atlantic Inter-Society Consensus (TASC II) classes C and D aortoiliac lesions ranged from 69% to 88%, with most clinicians reporting 4-year primary patency of between 75% and 80%.
Indications
Endovascular treatment for aortoiliac occlusive disease is indicated for lifestyle-limiting claudication, nocturnal metatarsalgia, or ischemic ulceration. Less frequent indications include treatment of vasculogenic impotence and atheroembolization to the lower extremities. Aortoiliac lesions most suitable for endovascular therapy can be guided by the newly revised TASC II guidelines ( Fig. 30-1 and Table 30-1 ). Endovascular therapy is a first-line therapy for symptomatic patients with TASC II A and B lesions, whereas surgical therapy is usually considered for TASC II D lesions and for low-risk patients with TASC II C disease. Although less durable than open surgical options, endovascular therapy may be applicable for high-risk patients with advanced associated comorbidities, such as severe chronic obstructive pulmonary disease, unreconstructable coronary artery disease, and low cardiac ejection fraction with TASC II C and D level disease in the setting of critical limb ischemia.
| Lesion Type | Guidelines |
|---|---|
| A | Unilateral or bilateral stenoses of the CIA Unilateral or bilateral single short (≤3 cm) stenosis of the EIA |
| B | Short (≤3 cm) stenosis of the infrarenal aorta Unilateral CIA occlusion Single or multiple stenoses totaling 3-10 cm and involving the EIA but not extending into the CFA Unilateral EIA occlusion not involving the origins of the internal iliac artery or the CFA |
| C | Bilateral CIA occlusions Bilateral EIA stenoses 3-10 cm long not extending into the CFA Unilateral EIA stenosis extending into the CFA Unilateral EIA occlusion that involves the origins of the internal iliac artery and/or the CFA Heavily calcified unilateral EIA occlusion with or without involvement of the origins of the internal iliac artery and/or the origins CFA |
| D | Infrarenal aortoiliac occlusion Diffuse disease involving the aorta and both iliac arteries and requiring treatment Diffuse multiple stenoses involving the unilateral CIA, EIA, and CFA Unilateral occlusions of both the CIA and the EIA Bilateral occlusions of the EIA Iliac stenoses in patients with abdominal aortic aneurysm requiring treatment and not amenable to endograft placement or with other lesions requiring open aortic or iliac surgery |
Preoperative Preparation
- •
The use of aspirin (81-325 mg/day) or clopidogrel (75 mg/day) during the preoperative and postoperative periods is an accepted adjunct to diminish perioperative complications.
- •
Patients should undergo noninvasive physiologic arterial studies such as ankle-brachial index and toe pressure measurements if indicated. Additional diagnostic studies are indicated to assess the location and extent of arterial occlusive disease, as well as the degree of calcification.
- •
The use of arteriography as a diagnostic tool is rarely indicated. Less invasive imaging modalities are available that can provide anatomic detail without exposing the patient to an invasive procedure.
- •
Duplex arterial mapping (DAM) of the aortoiliac segment and common femoral arteries can provide an adequate assessment of the location of hemodynamically significant lesions. This modality is especially useful in patients with renal insufficiency who are at risk from contrast-induced renal dysfunction. Drawbacks to DAM include only a semiquantitative assessment of the degree of iliac calcification, the inability to adequately image the iliac system in certain patients because of overlying bowel gas or body habitus, and the need for a significant time commitment and a highly trained vascular technologist.
- •
Magnetic resonance arteriography has developed to the point that it can provide reliable assessment of the aortoiliac arterial segment, though there continues to be institutional variability in the accuracy of this modality. The major drawback to magnetic resonance arteriography is that it does not provide an accurate assessment of the degree of calcification of the aortoiliac lesions. Gadolinium-enhanced magnetic resonance arteriography is contraindicated in patients with renal insufficiency.
- •
Computed tomography (CT) arteriography has been used with success to evaluate the aortoiliac segment before intervention. The major drawbacks to this imaging modality include exposure to ionizing radiation and the need for iodinated contrast, with the associated risk of contrast-induced renal dysfunction. In appropriate patients CT arteriography gives an accurate assessment of lesion location, lesion extent, and degree of calcification. Based on CT arteriography evaluation, the severity of aortoiliac and femoral disease can be classified according to TASC II guidelines.
- •
Use of preprocedural fluids and low-osmolar or isosmolar contrast agents decreases the risk for contrast-induced nephropathy, defined as an increase in serum creatinine greater than 25% or 0.5 mg/dL (44.2 μmol/L) within 3 days of intravascular contrast administration in the absence of an alternative cause. Although the effect may be small, preprocedural treatment with N -acetylcysteine (NAC) may reduce the risk for contrast-induced nephropathy. Because free radicals are postulated to mediate contrast-induced nephropathy, alkalinizing renal tubular fluid with bicarbonate has been shown to reduce injury. The use of NAC and bicarbonate may have an additive protective effect. Patients with a baseline serum creatinine of at least 1.5 mg/dL should receive an intravenous bolus of 3 mL/kg/hr (154 mEq/L sodium bicarbonate in dextrose and water) for 1 hour immediately before contrast injection. Patients should receive the same fluid regimen at a rate of 1 mL/kg/hr during contrast exposure and for 6 hours after the procedure. NAC at 1200 mg taken orally twice daily the day before and the day of contrast administration is also recommended. Diuretics should be withheld on the day of contrast injection.
Pitfalls and Danger Points
- •
Stent migration or embolization
- •
Subintimal dissection. Intraarterial catheter placement should be confirmed after crossing an occlusion by aspiration of blood.
- •
Iliac artery or aortic rupture
- •
Atheroembolization
- •
Iliac occlusion. Plaque disruption or narrowing of the contralateral common iliac artery occurs during ipsilateral common iliac artery intervention.
- •
Late restenosis. Risk factors include TASC II C or D lesions and lesions in the external iliac artery.
Endovascular Strategy
Depending on the location and extent of the disease determined by preoperative imaging, an ipsilateral retrograde, contralateral, bilateral femoral, or brachial approach can be planned.
Initial Intraoperative Imaging
An arteriographic examination is performed at the time of intervention and includes oblique pelvic imaging of the iliac arteries to determine the location of internal iliac artery and common femoral artery bifurcation disease. A contralateral oblique projection opens the iliac artery bifurcations, whereas the ipsilateral oblique projection is most useful for the femoral artery bifurcations. Imaging of the infrainguinal runoff is a requisite before intervention in most patients to ensure that the etiology of distal occlusion is because of preexisting disease rather than embolization during the course of intervention.
Assessing Hemodynamic Significance
Pressure measurements across the lesion should be obtained in moderate stenoses by connecting the hub of the catheter and the side arm of the vascular sheath to the intraarterial pressure monitor. The catheter should be at least 1-Fr smaller than the sheath. Other options include the pullback method of withdrawing an end-hole catheter over a 0.014-inch guidewire across a lesion from proximal to distal or through use of a pressure wire. A peak-to-peak systolic pressure gradient at rest of 10 mm Hg or greater is indicative of a hemodynamically significant lesion. In the absence of a resting gradient due to a distal superficial femoral artery occlusion, hemodynamic significance can be determined by measuring the pressure gradient after intraarterial administration of nitroglycerin (100-200 mcg) to dilate distal runoff vessels in the affected extremity.
Concomitant Common Femoral Artery Disease
The determination to proceed with a percutaneous endovascular therapy or an open femoral approach is based on the presence of significant common femoral artery disease. Patients with at least 30% to 50% stenosis of the common femoral artery on imaging studies are usually treated with a hybrid approach that entails open femoral endarterectomy and patch angioplasty and simultaneous aortoiliac stent or stent-graft placement. In patients with less severe common femoral artery disease, a percutaneous approach alone is appropriate.
Calcification
The presence of severe calcification has significant implications on operative or interventional planning. Circumferential calcification more than 1 mm thick is a relative contraindication to aortoiliac angioplasty and stenting. Consideration should be given to the use of stent grafts in patients who have extensive calcification of the aortoiliac segment and are poor candidates for open surgery, particularly of the external iliac artery segment in elderly females. Potential advantages of a stent graft are decreased risk of bleeding and the ability to more aggressively dilate the iliac segment ( Fig. 30-2 ). A larger arterial sheath may be required, although recent improvements in design have reduced the sheath profile necessary for these devices.
