Aortoiliac Interventions
Joshua D. Kuban
Sun Ho Ahn
Timothy P. Murphy
Peripheral arterial disease (PAD) is a progressive common medical disease with a presentation that can vary from asymptomatic to extremity gangrene. Since the first percutaneous transluminal revascularization was performed by Dotter and Judkins in 1964, revolutionary changes have occurred in management of PAD. With advances in angioplasty and stents, endovascular management has become the mainstay therapy for aortoiliac arterial obstructive disease.
Indications
1. Disabling or lifestyle altering intermittent claudication—defined as reproducible pain or symptoms in the buttocks, thighs, or calves with exertion, which subsides with rest—that is refractory to medical therapy and lifestyle modifications
2. Critical limb ischemia: rest pain and/or tissue loss
3. The TransAtlantic Inter-Society Consensus (TASC) provides a general algorithm for surgical versus endovascular management of aortoiliac disease (TASC II) based on lesion morphology and location (Table 11.1). Routine use of TASC II classification has fallen out of favor as emerging data supports endovascular management of TASC C and D lesions. First-line endovascular treatment is indicated in nearly all cases of aortoiliac disease with surgery indicated for those who fail endovascular treatment.
4. Angioplasty is indicated for concentric, noncalcified, short (<3 cm) lesions.
5. Primary stent placement is recommended for complex stenosis and chronic total occlusions (CTOs).
6. Secondary stent placement is indicated for technically unsuccessful angioplasty (residual gradient ≥5 mm Hg or greater than 30% residual stenosis) and complications, including flow-limiting dissection and vessel perforation.
Contraindications
There are no absolute contraindications. Relative contraindications to arteriography apply to aortoiliac endovascular interventions.
1. Uncorrectable coagulopathy
2. History of life-threatening iodinated contrast allergy/reaction
3. Severe non-dialysis-dependent renal insufficiency
Preprocedure Preparation
1. History and physical exam should be performed, with a focus on the vascular system. The operator should perform the peripheral vascular exam and document locations and quality of pulses in the bilateral extremities.
2. Pertinent noninvasive imaging (pulse volume recording [PVR], multilevel segmental lower extremity brachial indices, computed tomographic angiography [CTA], or magnetic resonance angiography [MRA]) should be reviewed or obtained if necessary.
3. Preprocedure laboratory evaluations should include platelet count, creatinine/glomerular filtration rate (GFR), and coagulation profile.
4. Baseline ankle-brachial index (ABI) should be obtained prior to procedure.
5. Evaluation of acetylsalicylic acid (ASA) status for conscious sedation should be performed.
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6. Patients should halt oral intake as per institutional protocol.
7. Morning insulin dose should be reduced to half for patients for whom food is withheld.
8. If a contrast allergy exists—steroid pretreatment should be given (see Chapter 64).
9. For non-dialysis-dependent renal insufficiency, hydration with 0.9% saline at 1 mg/kg/h for 24 hours beginning at 2 to 12 hours prior to the procedure is recommended for patients without congestive heart failure. Although not routinely used in our practice, sodium bicarbonate and N-acetylcysteine may be helpful, but the data are equivocal (1). See Chapter 65.
10. Patients are started on dual antiplatelet therapy 1 week prior to intervention with 325 mg of aspirin and 75 mg of clopidogrel daily. Otherwise, 325 mg of aspirin and 300 mg of clopidogrel (loading dose) are administered prior to the procedure. Individual patient response to clopidogrel is not routinely evaluated.
11. Urinary bladder catheter is usually placed prior to the procedure.
12. Sterile preparation, including surgical clipping, of both inguinal regions and/or arm is performed.
13. Procedures are performed under conscious sedation with incremental intravenous aliquots of midazolam and fentanyl with hemodynamic and respiratory monitoring.
14. Prophylactic antibiotics are not routinely administered for aortoiliac interventions performed under sterile conditions, even for those with cardiac valve prostheses, or mitral valve prolapse or other valvulopathy.
Procedure
Diagnostic Arteriogram
1. CFA access is preferred. Left arm access may be required on occasion. For diagnostic portion of the exam, initial contralateral CFA access is usually preferred,
unless a CIA intervention is planned. Contralateral access allows complete imaging of the aorta, the iliac arteries, and the distal arteries and permits precise localization of the causative lesion(s). In addition, contralateral approach maintains the potential to intervene above or below the inguinal ligament on the symptomatic side without performing an additional puncture. For intervention, a second or ipsilateral CFA access may be required, especially in the case of ostial CIA lesions. When a palpable pulse is absent, fluoroscopically guided puncture of CFA using landmarks and/or vessel calcifications can be performed. Ultrasound is helpful for difficult cases but should be used in conjunction with fluoroscopy to avoid inadvertent external iliac access. Preprocedure CTA or MRA can assist in determining optimal access.
unless a CIA intervention is planned. Contralateral access allows complete imaging of the aorta, the iliac arteries, and the distal arteries and permits precise localization of the causative lesion(s). In addition, contralateral approach maintains the potential to intervene above or below the inguinal ligament on the symptomatic side without performing an additional puncture. For intervention, a second or ipsilateral CFA access may be required, especially in the case of ostial CIA lesions. When a palpable pulse is absent, fluoroscopically guided puncture of CFA using landmarks and/or vessel calcifications can be performed. Ultrasound is helpful for difficult cases but should be used in conjunction with fluoroscopy to avoid inadvertent external iliac access. Preprocedure CTA or MRA can assist in determining optimal access.
2. A diagnostic arteriogram of the infrarenal aorta and lower extremity(ies) should be performed. The diagnostic arteriogram may be tailored depending on preoperative CTA or MRA findings and/or in the presence of renal insufficiency to reduce contrast load.
3. Lesion significance can be determined by hemodynamic gradient measurements or diameter reduction measurement. Generally, a resting mean trans-stenotic gradient ≥5 mm Hg or a systolic gradient >10 mm Hg is considered significant. Following augmentation by a vasodilator (e.g., 100 µg nitroglycerin given intra-arterially), a mean gradient >10 mm Hg or systolic gradient >20 mm Hg is significant. Diameter reduction >50% is considered significant. Hemodynamic measurements across total occlusions are unnecessary.
4. Pressure gradients are considered the gold standard and can be measured by several methods.
a. Double access simultaneous measurement above and below the lesion is most accurate.
b. Coaxial simultaneous measurement requires a 2-Fr.-sized difference between the sheath and the catheter.
c. Pullback pressures may be unreliable and affected by temporal variation in blood pressure.
d. Pressure wires may be more accurate in smaller sized arteries due to less flow reduction by the catheter or the sheath but add to the cost and procedure time.
Techniques General to All Interventions
1. Once the determination to intervene has been made, systemic anticoagulation is achieved with intravenous heparin unless contraindicated. Activated clotting time (ACT) during the procedure can be done with a working goal of 250 seconds.
2. Intervention should be performed through an appropriately sized sheath. A 6 Fr. sheath can accommodate most stents and balloons used in the iliac system. For contralateral intervention, a long braided sheath (e.g., Pinnacle Destination, Terumo Medical, Somerset, NJ; or BRITE TIP, Cordis, Bridgewater, NJ) should be advanced over the bifurcation.
3. The lesion must be crossed. Most stenoses can be negotiated with a long taper (LT) straight guidewire and an angled-tip catheter. More complex stenoses may require a steerable hydrophilic guidewire (e.g., Glidewire, Terumo Medical, Somerset, NJ) with a directable catheter (e.g., Kumpe, Cook Medical, Bloomington, IN).
