Study Questions: Chapter 13 Chapter 13: Aortoiliac Intervention BRYAN P. YAN, MBBS Study Questions: Chapter 13 * 1.) A patient presents with buttock claudication with walking one block. On examination, femoral pulses are normal. What is the most appropriate screening test to assess the severity of the iliac stenoses? Resting ankle-brachial index Resting and exercise ankle-brachial index Magnetic resonance angiography Computed tomography angiography Show answerThe correct answer is 2, Resting and exercise ankle-brachial index. Although resting ankle-brachial index (ABI) is a simple and reliable means for diagnosing peripheral artery disease (PAD), its diagnostic utility is limited in patients with aortoiliac disease. In such cases, patients may have normal ABIs at rest and palpable distal pulses despite classic symptoms of claudication. Even with a normal ABI at rest, after exercise stress testing the pulses may no longer be palpable and the ABI will likely fall. Both MRA and CTA have high spatial resolution in delineating anatomy and diagnostic accuracy for PAD. However, they are not ideal screening tests and only should be performed if intervention is considered. * 2.) Which of the following features would not be considered favorable for endovascular iliac intervention? Stenosis length of 4 cm Focal occlusion Two patent runoff vessels Calcified lesion Show answerThe correct answer is 4, Calcified lesion. Stenosis length <5 cm and focal occlusions are con- sidered TASC A lesions for which endovascular therapy is recommended, according to the current TASC II guidelines. Primary success rate of endovascular therapy for these simple lesions is high, and long-term patency is comparable to bypass surgery. Inadequate infrainguinal runoff is considered a risk factor for iliac stent failure. Two patent runoff vessels are considered favorable for iliac intervention. Calcified lesions are associated with lower success rates but higher rates of complications, including dissection, perforation, and restenosis. * 3.) Which of the following is the strongest indication for bypass surgery? Bilateral common iliac occlusion >10 cm unilateral occlusion of common and external iliac artery Operator inexperience with endovascular intervention Heavily calcified lesion Show answerThe correct answer is 3, Operator inexperience with endovascular intervention. Current recommendations favor endovascular procedures for TASC A and B lesions, and for selected C lesions such as bilateral common iliac occlusion and heavily calcified lesions. Patients with TASC D lesions such as unilateral occlusion of common and external iliac artery generally are considered surgical candidates, but with newer technology such as reentry devices and covered stent grafts, these patients are increasingly considered for endovascular therapy. Although many studies have shown that endovascular therapy of aortoiliac disease is safe, complications including thrombosis, distal embolization, pseudoaneurysm, and arterial rupture can occur, especially with more complex lesions. Therefore, operator experience in endovascular therapy is essential. * 4.) Which modality has the least favorable outcome for common iliac lesions? Balloon angioplasty alone Balloon-expandable bare-metal stent Balloon-expandable covered stent Anatomical bypass graft Show answerThe correct answer is 1, Balloon angioplasty alone. Current American College of Cardiology/American Heart Association Class I guideline recommendation is for primary stent placement in the iliac arteries (level of evidence B for common iliac arteries and C for external iliac arteries), and this is supported by a meta-analysis that reviewed more than 2000 patients. Procedural success was higher in the primary stent group, and there was a 43% reduction in long-term (4-year) failures for aortoiliac stent placement, compared with balloon angioplasty alone. Four-year primary patency rates were 44% to 65% after balloon angioplasty, compared to 53% to 77% after stent placement. The COBEST trial showed that aortoiliac lesions treated with a covered stent were more likely to remain free from binary restenosis than those treated with a bare-metal stent. Patency of anatomical aortic bifurcation bypass grafts has been shown to be 90% and 75% at 5 and 10 years, respectively. By comparison, extra-anatomic bypass graft 5-year patency ranges from 51% (44%–79%) for axillary-unifemoral bypass graft to 71% (50%– 76%) for axillary-bifemoral bypass to 75% (55%– 92%) for femorofemoral crossover graft. * 5.) A 63-year-old man complains of lower back and buttock claudication with ambulation. At an outside hospital, he underwent stent implantationto the left common iliac artery. However, his symptoms did not improve. Based on the angiogram shown below, what is the next appropriate step in his management? Reexpand the left common iliac artery stent PTA and stent of the right hypogastric artery Refer to pain management clinic Obtain CT to evaluate his lumbosacral spine Show answerThe correct answer is 2. The angiogram shows patent common and external iliac arteries. The right hypogastric artery demonstrates a high-grade stenosis. The left hypogastric artery is occluded. A balloon-expandable stent was deployed in the right hypogastric artery (see figure below). At follow-up, the patient’s symptoms had resolved. Internal iliac artery stenosis can cause localized thigh and buttock claudication that may resolve following endovascular treatment of internal iliac artery stenosis. Nonvascular causes of buttock pain should be evaluated if the vascular assessment is nondiagnostic.