Special Problems in the Endovascular Treatment of Aortoiliac Occlusive Disease

Historical Background

In recent years there has been a shift in the treatment of aortoiliac occlusive disease (AIOD) from open surgical treatment to endovascular interventions. Endovascular treatment for Trans-Atlantic Inter-Society Consensus (TASC) class A lesions is considered standard. Recommendations are not as clear for more complex disease, including TASC class B and C lesions, but even these are often treated with interventional therapy with excellent results. As catheter-based interventions have advanced, the treatment spectrum has widened to include TASC class D lesions ( Table 31-1 ). Although, a surgical approach continues to be recommended for patients with low operative risk for complex aortic and iliac TASC class D lesions, recent studies have revealed comparable technical success and durability when compared with open reconstruction. A hybrid approach for treating occlusive disease that extends into the femoral arteries has further increased endovascular options for AIOD.

Preoperative Care

• Preoperative physical examination should include a determination of ankle-brachial index; assessment of severity of comorbidities, including renal, cardiac, and functional limitations; and estimated life expectancy. Patients who cannot tolerate general anesthesia and have limited life expectancy, minimal functional performance, or a hostile abdomen may be better served with endovascular treatment.

• Preoperative imaging is performed to determine the extent of aortoiliac disease, with particular attention given to associated common femoral artery or infrainguinal disease. Computed tomography angiography is preferred over conventional angiography and magnetic resonance angiography because of its capacity to assess arterial calcification. In patients with renal insufficiency (estimated glomerular filtration rate of less than 45 mL/min/1.73 m ² ), hydration is recommended before and after the imaging.

• Optimization of comorbidities should be undertaken as follows:

  • Patients with significant renal insufficiency should be admitted before intervention for hydration. Volume loading with sodium bicarbonate and N -acetylcysteine has been shown to reduce risk of renal failure.

  • Smoking cessation reduces graft failure, risk of myocardial infarction, and progression of peripheral artery disease.

  • Perioperative beta-blockade is recommended for patients with cardiac disease.

  • Aspirin is recommended at a daily dosage of 162 to 325 mg, and clopidogrel (75 mg daily) has been found to reduce the risk of ischemic events.

• Most endovascular procedures can be performed under local anesthesia and sedation. However, if a hybrid procedure is planned, regional or general anesthesia is recommended. Cardiac stress testing has been recommended for patients undergoing vascular surgery, but recent evidence suggests a selective approach to testing may be appropriate based on the application of a cardiac risk index.

Pitfalls and Danger Points

• Rupture. Increased risk in small, calcified vessels is often observed in female patients. The external iliac artery is most vulnerable. In high-risk situations an access sheath should be selected at the outset that allows delivery of a covered stent.

• Dissection

• Embolization

• Thrombosis. Activated clotting time (ACT) should be maintained between 250 and 300 seconds during interventions.

• Access site bleeding

Endovascular Strategy

The TASC classification of aortic and iliac artery occlusive disease provides a framework for considering endovascular options and outcomes (see Table 30-1 ). Endovascular treatment is preferred for TASC class A and B lesions. However, surgery should be considered for treatment of TASC class C and D disease in patients at low operative risk, with endovascular approaches reserved for high-risk patients or those with other factors, such as a hostile abdomen, that would complicate surgical repair.