Aortic aneurysm Flashcards
(39 cards)
What are the risk factors associated with abdominal aortic aneurysm (AAA)?
Risk factors associated with development of AAA include older age (≥60), male sex, cigarette smoking, family history of AAA, and atherosclerotic disease.
A 60-year-old man undergoes imaging that reveals a 3.5-cm abdominal aortic aneurysm. The finding is incidental; he has no associated symptoms. Medical history is significant for hypertension, type 2 diabetes mellitus, hypercholesterolemia, and hypothyroidism. Current medications include aspirin, metformin, glipizide, chlorthalidone, lisinopril, atorvastatin, and levothyroxine. The patient has a 40-pack-year history and continues to smoke 1-2 packs a day. He drinks 3 or 4 glasses of wine daily. Blood pressure is 160/90 mm Hg and pulse is 80/min. Cardiopulmonary examination is normal.
Which of the following interventions would most effectively decrease the likelihood of expansion of this patient’s aortic aneurysm?
A. Aggressive diabetes mellitus management
B. Improved blood pressure control
C. Moderation of alcohol consumption
D. Optimized hyperlipidemia treatment
E. Smoking cessation
Current cigarette smoking is the most important modifiable risk factor and has been associated with the highest rate of aneurysm expansion and rupture. The pathophysiology is likely due to increased inflammation and degeneration of connective tissue in the aortic wall. Therefore, smoking cessation is essential for prevention and has the greatest impact on decreasing the likelihood of aneurysm expansion. Most patients with abdominal aortic aneurysm (AAA) are initially asymptomatic, and the diagnosis is often revealed by imaging ordered for an unrelated cause. Risk factors associated with development of AAA include older age (≥60), male sex, cigarette smoking, family history of AAA, and atherosclerotic disease. The natural history of AAA is characterized by progressive expansion over time with an increasing risk of rupture. Risk factors associated with aneurysm rupture include large diameter (rupture risk increases from 10%-20%/year for 6-cm aneurysms to 30%-50%/year for aneurysms >8 cm), rate of expansion (>0.5 cm in 6 months), and current cigarette smoking. Studies have shown a weak association between hypertension, AAA formation, and rate of expansion and rupture. Patients with AAA need adequate blood pressure control for overall cardiovascular risk reduction, but treatment with antihypertensive agents (including beta blockers) has not been clearly shown to reduce the rate of aneurysm expansion.
Does dyslipidemia increase the risk of AAA?
Hyperlipidemia is an important modifiable risk factor for atherosclerosis, but it has not been found to be reliably associated with AAA expansion. Although lipid-lowering agents are often prescribed to reduce the risk of other cardiovascular events, there is conflicting evidence on their effect on AAA expansion.
Does diabetes increase the risk of AAA?
Diabetes mellitus is a strong risk factor for atherosclerosis and cardiovascular disease. However, studies have shown a lower risk of AAA development and expansion in patients with diabetes mellitus compared to those without diabetes mellitus, for unclear reasons.
What genetic conditions increase the risk of developing AAA?
Connective tissue diseases (Marfan and Ehlers-Danlos).
What is the most common clinical sign of AAA?
Mostly asymptomatic.
What defines an abdominal aortic aneurysm (AAA)?
Focal aortic dilation greater than 3 cm in diameter. Even though dilation of 3 cm or more is the definition, AAA only needs intervention when 5.5 cm (or rapid expanding or exceeding a rate of 1 cm of expansion or more annually).
A 55-year-old man comes to the emergency department for evaluation of left flank pain that woke the patient up abruptly from sleep. Also he saw blood in his urine with his first urination of the day. The patient has a past medical history of nephrolithiasis, hypertension, hyperlipidemia, diabetes, and a 20-pack-year smoking history. On physical examination, the patient appears uncomfortable and diaphoretic. Temperature is 37°C (98.6°F), blood pressure is 120/66, pulse is 105/min, respiratory rate is 16/min, and oxygen saturation is 97% on room air. Physical exam reveals left costovertebral angle tenderness, and a pulsatile abdominal mass is palpated. Urinalysis shows hematuria. A bedside ultrasound shows an abdominal aortic aneurysm that is 3.5 cm in diameter as demonstrated below. A CT of the abdomen and pelvis without contrast demonstrates a 5 mm obstructing left kidney stone. What is the best management for the abdominal aneurysm finding?
Performing serial abdominal ultrasounds in the outpatient setting is the best management of asymptomatic abdominal aortic aneurysms that are ≤ 5.5 cm in diameter and are found incidentally. This patient presents for evaluation of acute onset left flank pain and hematuria and is found to have a left kidney stone on CT. He has an incidental finding of an abdominal aortic aneurysm (AAA). Given that the aneurysm diameter is less than 5.5 cm, it is at low risk for rupture. The patient has an alternative etiology to explain his symptoms. Therefore he has an asymptomatic AAA that is less than 5.5 cm The best management is to follow him with outpatient serial abdominal ultrasounds. An abdominal aortic aneurysm (AAA) is defined as aortic dilatation greater than 3 cm in diameter. Most AAAs are fusiform, which means they’re spindle-shaped and involve the entire circumference of the aortic wall. AAAs can be symptomatic or asymptomatic. While most AAAs are asymptomatic and found incidentally on imaging studies, all AAAs are at risk for expansion and rupture. Management of AAA is dependent on patient stability. Patients that are unstable, meaning those with evidence of hypotension, altered mental status, airway compromise, and rupture should have emergent surgical consultation for open or endovascular repair. Stable patients with evidence of a symptomatic AAA should receive surgical consultation for possible surgical or endovascular repair. Patients who are found to have an abdominal aortic aneurysm incidentally that is ≤ 5.5 cm, should be monitored in the outpatient setting with serial abdominal ultrasounds.
When are patients in the population screened for AAA?
Screen all males if they have ANY history of smoking and are between the years of 65 to 75.
What are the risk factors for AAA?
Smoking (25x), advanced age and male gender (8x), hyperlipidemia and hypertension (4x), and atherosclerotic disease.
While all these factors contribute to the development of AAA, smoking is the single most important and modifiable risk factor, followed by age and male gender as the strongest non-modifiable factors.
How does ethnicity or race play into the risk for AAA?
Ethnicity and race do affect both prevalence and risk, although the effect on prevalence is more pronounced. Factors like smoking, hypertension, and healthcare access remain crucial in determining individual risk across all populations.
What is the typical clinical presentation of a stable AAA?
Usually asymptomatic, but if symptomatic, it can cause pressure or pain in the abdomen or back. Associated symptoms include a pulsatile abdominal mass or hypovolemic shock if the aneurysm ruptures.
What does dull abdominal or dull back pain mean in the context of AAA?
This usually indicates rapid expansion of AAA.
Where do abdominal aortic aneurysms most commonly occur in the abdomen?
Below the kidneys (infrarenal)
What is a MAJOR complication of AAA?
The aneurysmatic dilatation of the vessel wall may cause disruption of the laminar blood flow and turbulence. Formation of a thrombus is a real possibility, leading to a distal embolus. This usually implies that the AAA is rapidly expanding.
what are the common symptoms of a AAA when less than 5.5 cm (not rapidly expanding)?
The most common symptom of a small, stable abdominal aortic aneurysm (AAA) (<5.5 cm, not rapidly expanding) is none—it is typically asymptomatic and found incidentally on imaging. If symptoms do occur, the most common presenting symptom is mild, chronic abdominal or back pain, often dull, vague, and non-specific.
What is the guides the different imaging modalities between stable vs unstable ruptured AAA?
Imaging depends on the patient’s hemodynamic stability and the urgency of diagnosis.
What is the initial diagnostic test of choice for AAA?
Abdominal ultrasound (US).
What is the imaging modality of choice following US for a stable patient with a suspected AAA?
Abdominal CTA.
What is the management approach for asymptomatic AAA?
- For diameter is ≥ 5.5 cm: Surgery with a endovascular aneurysm repair
- For diameter expanding >1 cm/year: Surgery with a endovascular aneurysm repair
- For an aneurysm that is expanding rapidly: Surgery with a endovascular aneurysm repair
- For symptomatic aneurysms: Elective surgical repair
- For smaller aneurysms: observation with q 6-12 month ultrasounds depending on size
- For all aneurysms: risk factor modification (STOP smoking !!!)
Has blood pressure control with antihypertensive agents been proven to significantly decrease the risk of AAA?
Studies have shown a weak association between hypertension, AAA formation, and rate of expansion and rupture. Patients with AAA need adequate blood pressure control for overall cardiovascular risk reduction, but treatment with antihypertensive agents (including beta blockers) has not been clearly shown to reduce the rate of aneurysm expansion.
Has alcohol been proven to significantly increase the risk of AAA?
The effect of moderate alcohol consumption (eg, 1 or 2 drinks/day in men and 1 drink/day in women) on all types of cardiovascular disease remains unclear. There are no convincing data to confirm that moderate alcohol consumption increases the risk of AAA formation, and alcohol use is not considered a risk factor for AAA expansion or rupture.
What would be the modality to assess for cardiac strength prior to performing a surgery for abdominal aortic aneurysm repair?
Radionuclide dipyridamole thallium
What are the risk factors for AAA rupture?
Current cigarette smoking is the most important modifiable risk factor and has been associated with the highest rate of aneurysm expansion and rupture. The pathophysiology is likely due to increased inflammation and degeneration of connective tissue in the aortic wall. Therefore, smoking cessation is essential for prevention and has the greatest impact on decreasing the likelihood of aneurysm expansion. Most patients with abdominal aortic aneurysm (AAA) are initially asymptomatic, and the diagnosis is often revealed by imaging ordered for an unrelated cause. disease. The natural history of AAA is characterized by progressive expansion over time with an increasing risk of rupture. Risk factors associated with aneurysm rupture include large diameter (rupture risk increases from 10%-20%/year for 6-cm aneurysms to 30%-50%/year for aneurysms >8 cm), rate of expansion (>0.5 cm in 6 months), and current cigarette smoking.
