Study Questions: Chapter 10 Chapter 10: Epidemiology and Natural History of Peripheral Artery Disease ELIZABETH V. RATCHFORD, MD; MAYA J. SALAMEH, MD Study Questions : Chapter 10 * Which of the following causes of claudication is most closely associated with superficial thrombophlebitis? Fibromuscular dysplasia Thromboangiitis obliterans Popliteal artery entrapment syndrome Critical limb ischemia Show answerThe correct answer is 2, Thromboangiitis obliterans. Thromboangiitis obliterans is a nonatherosclerotic segmental inflammatory disease that affects small and medium-sized arteries, veins, and nerves of the extremities, resulting in the formation of inflammatory and highly cellular occlusive thrombus within the affected vessels. In contrast to atherosclerotic PAD, thromboangiitis obliterans often involves the venous system such that up to 40% of patients may experience superficial thrombophlebitis. (3) Fibromuscular dysplasia, popliteal artery entrapment syndrome, and critical limb ischemia are conditions that only affect the arterial system and are not typically associated with venous pathology. * Which of the following is the best interpretations of the study in figure 10.Q2? Medical Calcification has rendered the segmental preassures unreliable. Based on the PVR tracings: no evidence of significant peripeheral artery disease. Bilateral infrapopliteal disease involving both the anterior tibial/dorsalis pedis and posterior tibial arteries. Aortoiliac or bilateral iliofemoral disease, with possible additional infrapopliteal disease on the left. Aortoiliac or bilateral iliofemoral disease, with additional bilateral femoral-popliteal disease (left worse than right). Show answerThe correct answer is 3. Segmental pressures normally increase from theproximal to the distal lower extremity. A drop inpressures between 2 segments is abnormal, and adrop >20 mmHg is suggestive of significant obstructionwithin that segment. There is a >20 mmHg dropin pressure from the higher brachial pressure to boththighs (50 mmHg drop on the right, and 57 mmHgon the left), suggesting significant arterial obstructioneither in the distal aorta (affecting both legsequally) or the bilateral iliofemoral segments. Anadditional drop in pressure is noted from the left calfto the left ankle dorsalis pedis, a finding that suggestsinfrapopliteal (anterior tibial) disease. However, thedrop is not >20 mmHg. The PVR tracings are moderatelyabnormal at the bilateral thighs, with lossof dicrotic notch and a decrease in amplitude. Thisis consistent with the observed drop in pressure atthat level. A is incorrect. There is no evidence of medial calcification, and the PVR tracings are abnormal. B is incorrect. Except for a small drop in pressure from the left calf to the left ankle DP, the pressures at the ankles are not significantly lower than at the calf segment. D is incorrect. There is no evidence of femoralpopliteal disease, as no significant drop in pressure is noted from the thigh to the calf on either side.in pressureis noted from the thigh to the calf on either side. * Which of the following patients should be referred for diagnostic ABI testing? A 35-year-old man who smokes, has a family history of early coronary disease, and reports pain in his left knee when walking A 55-year-old woman with hypertension who reports leg cramps during the night A 68-year-old man with spinal stenosis who reports back pain associated with exertional thigh fatigue An 80-year-old woman with hyperlipidemia and hypertension who otherwise feels well Show answerThe correct answer is 3, A 68-year-old man with spinal stenosis who reports back pain associated with exertional thigh fatigue. This patient is considered at risk for PAD based on his age. He is reporting exertional thigh fatigue that could be attributed to spinal stenosis since he has concomitant back pain. However, these symptoms could also be a manifestation of claudication, and given that the patient is at risk for PAD, he should be referred for diagnostic ABI testing. Postexercise ABIs may also be informative if the resting study is normal or borderline normal. 1 is incorrect, as a 35-year-old is very unlikely to have PAD based on his age, and his knee pain is not suggestive of claudication. 2 is incorrect, as the patient does not have exertional leg symptoms and is not considered at high risk for PAD. Leg cramps during the night are not suggestive of PAD. 4 is incorrect, as the patient is asymptomatic. Although she has many risk factors for PAD and may be considered for screening ABI testing, she would not be a candidate for diagnostic ABI testing. * Which of the following physical exam findings most significantly increases the likelihood of atherosclerotic peripheral artery disease? A faintly palpable dorsalis pedis pulse Increased hair on the lower legs and toes The presence of a femoral bruit A prominent popliteal pulse Show answerThe correct answer is 3,The presence of a femoral bruit. A study published in the Journal of the American Medical Association revealed that the presence of a femoral bruit significantly increases the likelihood of PAD, although its absence does not affect the probability that PAD is present.(24) 1 is incorrect. Although a faintly palpable dorsalis pedis pulse may be suggestive of PAD, an abnormal dorsalis pedis pulse has low sensitivity and specificity for the detection of PAD.(25) 2 is incorrect. Decreased hair on the leg and toes, not increased, is suggestive of but not specific for PAD. 4 is incorrect. A prominent popliteal pulse may be suggestive of popliteal aneurysm, not obstructive PAD, which would more likely be associated with a decreased or absent popliteal pulse. Based on the most recent guidelines, which of the following is considered the normal range for the ankle-brachial index (ABI)? 1.0‒1.4 0.9‒1.3 0.7‒0.99 >0.9 Show answerThe correct answer is 1, 1.0‒1.4. Based on the publication of the results of the Ankle Brachial Index Collaboration,(27) the guidelines have recently been updated, and the new range for a normal ABI is 1.0‒1.4. An ABI of ≤0.90 is abnormal, and a value from 0.91 to 0.99 is considered “borderline.” An ABI of >1.40 indicates that the arteries are not compressible. 2 is incorrect. This ABI range includes the borderline ABI (0.91‒0.99) and excludes ABI 1.3‒1.4, which is still considered normal. 3 is incorrect. An ABI of ≤0.90 is abnormal. 4 is incorrect. An ABI with a value from 0.91 to 0.99 is considered “borderline” but not normal.