Vascular Surgery US Medical PG Practice Questions and MCQs
Practice US Medical PG questions for Vascular Surgery. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Vascular Surgery US Medical PG Question 1: A 72-year-old woman comes to the physician for follow-up care. One year ago, she was diagnosed with a 3.8-cm infrarenal aortic aneurysm found incidentally on abdominal ultrasound. She has no complaints. She has hypertension, type 2 diabetes mellitus, and COPD. Current medications include hydrochlorothiazide, lisinopril, glyburide, and an albuterol inhaler. She has smoked a pack of cigarettes daily for 45 years. Her temperature is 37°C (98.6°F), pulse is 90/min, respirations are 12/min, and blood pressure is 145/85 mm Hg. Examination shows a faint abdominal bruit on auscultation. Ultrasonography of the abdomen shows a 4.9-cm saccular dilation of the infrarenal aorta. Which of the following is the most appropriate next step in management?
- A. Elective endovascular aneurysm repair (Correct Answer)
- B. Adjustment of cardiovascular risk factors and follow-up ultrasound in 12 months
- C. Adjustment of cardiovascular risk factors and follow-up ultrasound in 6 months
- D. Elective open aneurysm repair
- E. Adjustment of cardiovascular risk factors and follow-up CT in 6 months
Vascular Surgery Explanation: ***Elective endovascular aneurysm repair***
- The patient's **infrarenal aortic aneurysm** has grown from 3.8 cm to 4.9 cm in one year, approaching the **5.0 cm threshold for intervention in women** (compared to 5.5 cm for men). The **rapid growth rate of 1.1 cm/year** (normal is <0.5 cm/year) significantly increases rupture risk and is an indication for intervention even before reaching the absolute size threshold.
- Given her multiple comorbidities (hypertension, diabetes, COPD, 45 pack-year smoking history), **endovascular aneurysm repair (EVAR)** is preferred over open repair due to lower perioperative morbidity and mortality in high-risk surgical candidates.
- The combination of near-threshold size and rapid growth makes elective repair appropriate now rather than continued surveillance.
*Adjustment of cardiovascular risk factors and follow-up ultrasound in 12 months*
- While **risk factor modification** (smoking cessation, blood pressure control) is essential, it is insufficient as the primary management given the aneurysm's significant growth and imminent rupture risk.
- A 12-month follow-up interval is too long for a rapidly growing aneurysm (grew 1.1 cm in the past year), as this increases the risk of rupture without intervention.
*Adjustment of cardiovascular risk factors and follow-up ultrasound in 6 months*
- **Risk factor management** is important but does not address the immediate need for intervention due to the aneurysm's size approaching the threshold and concerning growth rate.
- While 6-month surveillance might be considered for smaller aneurysms with slower growth, this aneurysm's rapid expansion rate suggests it will exceed 5.0 cm well before the next surveillance interval, increasing rupture risk unnecessarily.
*Elective open aneurysm repair*
- **Open aneurysm repair** is an effective treatment but carries significantly higher perioperative risks (30-day mortality 3-5% vs 1-2% for EVAR) compared to endovascular repair, especially in patients with multiple comorbidities.
- Given this patient's COPD, smoking history, and cardiovascular risk factors, EVAR is the preferred approach to minimize surgical stress and improve perioperative outcomes.
*Adjustment of cardiovascular risk factors and follow-up CT in 6 months*
- **Risk factor modification** alone is insufficient given the aneurysm's proximity to intervention threshold and rapid growth rate.
- While CT provides more detailed anatomic imaging for surgical planning, continued surveillance is inappropriate when the patient already meets criteria for intervention. Additionally, CT involves radiation exposure and is typically reserved for pre-operative planning rather than routine surveillance.
Vascular Surgery US Medical PG Question 2: A 62-year-old woman with no significant past medical history presents with progressive dyspnea on exertion over the past 6 months. Echocardiogram reveals elevated pulmonary artery pressure (PAP) of 55 mmHg with normal left ventricular ejection fraction and no evidence of left-sided valvular disease. Right heart catheterization confirms mean PAP of 50 mmHg with pulmonary capillary wedge pressure of 10 mmHg. Intraoperative administration of intravenous adenosine causes the PAP to decrease to 35 mmHg. What pharmacological therapy is most likely to provide long-term benefit for this patient?
- A. Amlodipine (Correct Answer)
- B. Bosentan
- C. Epoprostenol
- D. Sildenafil
- E. Adenosine
Vascular Surgery Explanation: ***Amlodipine***
- The patient has **idiopathic pulmonary arterial hypertension (PAH, Group 1 PH)** confirmed by elevated mean PAP >20 mmHg with normal pulmonary capillary wedge pressure (≤15 mmHg), excluding left heart disease.
- The **positive acute vasodilator response** (PAP drop >10 mmHg to <40 mmHg) during right heart catheterization indicates **vasoreactivity**, which predicts favorable response to **calcium channel blockers (CCBs)**.
- **Amlodipine** or other CCBs (nifedipine, diltiazem) are the **first-line long-term therapy** for vasoreactive idiopathic PAH, with some patients achieving near-normalization of PAP.
- Only about **10% of idiopathic PAH patients** are vasoreactive, making this finding clinically significant.
*Bosentan*
- **Bosentan** is an **endothelin receptor antagonist** used for **PAH (Group 1)**.
- While effective for PAH, it is typically reserved for patients who are **non-vasoreactive** or who fail CCB therapy.
- Given this patient's positive vasodilator response, a **CCB trial is preferred first** due to better long-term outcomes in vasoreactive patients.
*Epoprostenol*
- **Epoprostenol** is a **prostacyclin analog** used for severe **PAH**, particularly WHO functional class III-IV.
- It requires **continuous intravenous infusion** and is reserved for more advanced or refractory PAH.
- Not appropriate as **first-line therapy** in a vasoreactive patient who can be treated with oral CCBs.
*Sildenafil*
- **Sildenafil** is a **phosphodiesterase-5 inhibitor** effective for **PAH**.
- Like bosentan, it is used for patients who are **non-vasoreactive** or have failed CCB therapy.
- In a vasoreactive patient, **CCBs are preferred** due to superior long-term outcomes in this subset.
*Adenosine*
- **Adenosine** is an **ultrashort-acting vasodilator** used as a **diagnostic agent** during right heart catheterization to assess vasoreactivity.
- It has a half-life of seconds and is **not suitable for long-term therapy**.
- Alternative agents for vasoreactivity testing include inhaled nitric oxide and intravenous epoprostenol.
Vascular Surgery US Medical PG Question 3: A 43-year-old man comes to the physician because of increasing shortness of breath for 1 month. He has been using two pillows at night but frequently wakes up feeling as if he is choking. Five months ago, he underwent surgery for creation of an arteriovenous fistula in his left upper arm. He has hypertension and chronic kidney disease due to reflux nephropathy. He receives hemodialysis three times a week. His current medications are enalapril, vitamin D3, erythropoietin, sevelamer, and atorvastatin. His temperature is 37.1°C (98.8°F), respirations are 22/min, pulse is 103/min and bounding, and blood pressure is 106/58 mm Hg. Examination of the lower extremities shows bilateral pitting pedal edema. There is jugular venous distention. A prominent thrill is heard over the brachiocephalic arteriovenous fistula. There are crackles heard at both lung bases. Cardiac examination shows an S3 gallop. The abdomen is soft and nontender. Which of the following is the most likely cause of this patient's symptoms?
- A. AV fistula aneurysm
- B. Pulmonary embolism
- C. Constrictive pericarditis
- D. Dialysis disequilibrium syndrome
- E. High-output heart failure (Correct Answer)
Vascular Surgery Explanation: ***High-output heart failure***
- The patient's symptoms of **dyspnea, orthopnea, pitting edema, jugular venous distention, crackles**, and **S3 gallop** strongly indicate **heart failure**. The **bounding pulse** and **wide pulse pressure** (systolic 106, diastolic 58) in the presence of an **arteriovenous fistula** suggest a **high-output state**.
- An **arteriovenous fistula** used for hemodialysis can significantly increase **cardiac preload** and reduce **afterload**, leading to a persistent increase in **cardiac output**. Over time, this chronic increase in demand can overwhelm the heart, resulting in **high-output heart failure**.
*AV fistula aneurysm*
- An **AV fistula aneurysm** is a localized dilatation of the fistula and would typically present as a painful or compressible mass.
- While it's a complication of AV fistulas, it does not directly explain the systemic signs of **heart failure** observed in this patient.
*Pulmonary embolism*
- **Pulmonary embolism** typically presents with sudden onset **dyspnea, pleuritic chest pain**, and sometimes **tachycardia** and **hypoxia**.
- This patient's symptoms are of gradual onset, accompanied by clear signs of **fluid overload** and **cardiac dysfunction** like an S3 gallop, which are not typical for a PE.
*Constrictive pericarditis*
- **Constrictive pericarditis** causes symptoms of **right-sided heart failure** due to impaired diastolic filling, often with a **pericardial knock** and **Kussmaul's sign**.
- While it can manifest with pedal edema and JVD, the **S3 gallop** and especially the **bounding pulse** and **wide pulse pressure** are inconsistent with constrictive pericarditis, which would typically cause a low-output state.
*Dialysis disequilibrium syndrome*
- **Dialysis disequilibrium syndrome** occurs shortly after hemodialysis, usually during or immediately after the first few sessions. It is characterized by neurological symptoms such as **headache, nausea, vomiting, confusion**, and **seizures**.
- The patient's symptoms have been evolving over a month and describe a state of **fluid overload** and **cardiac dysfunction**, not acute neurological symptoms related to dialysis.
Vascular Surgery US Medical PG Question 4: A 69-year-old woman is admitted to the hospital with substernal, crushing chest pain. She is emergently moved to the cardiac catheterization lab where she undergoes cardiac angiography. Angiography reveals that the diameter of her left anterior descending artery (LAD) is 50% of normal. If her blood pressure, LAD length, and blood viscosity have not changed, which of the following represents the most likely change in LAD flow from baseline?
- A. Decreased by 93.75% (Correct Answer)
- B. Increased by 6.25%
- C. Decreased by 25%
- D. Decreased by 87.5%
- E. Increased by 25%
Vascular Surgery Explanation: ***Decreased by 93.75%***
- This option is correct based on Poiseuille's Law, which states that flow is proportional to the **fourth power of the radius (r^4)**. A 50% decrease in diameter means a 50% decrease in radius (0.5r).
- The new flow would be (0.5)^4 = 0.0625 times the original flow. Therefore, the decrease in flow is 1 - 0.0625 = 0.9375, or **93.75%**.
*Increased by 6.25%*
- This answer incorrectly suggests an **increase** in flow, which is contrary to the effect of a narrowed artery.
- While 6.25% represents the new flow as a percentage of baseline (since 0.0625 = 6.25%), the vessel stenosis causes a **decrease**, not an increase in flow.
*Decreased by 25%*
- This calculation might arise from considering a linear relationship (e.g., radius decreases by 50%, so flow decreases by 50% of 50%, which is incorrect).
- It does not account for the **fourth power relationship** between radius and flow according to Poiseuille's Law.
*Decreased by 87.5%*
- This percentage represents a calculation error, likely from misapplying the fourth power relationship or confusing the calculation steps.
- It does not accurately reflect the dramatic reduction in flow caused by a 50% reduction in vessel diameter.
*Increased by 25%*
- This option implies a significant increase in blood flow, which would not happen with a **stenosed artery**.
- It completely contradicts the physiological response to a **narrowed vessel**.
Vascular Surgery US Medical PG Question 5: A 78-year-old left-handed woman with hypertension and hyperlipidemia is brought to the emergency room because of sudden-onset right leg weakness and urinary incontinence. Neurologic examination shows decreased sensation over the right thigh. Muscle strength is 2/5 in the right lower extremity and 4/5 in the right upper extremity. Strength and sensation in the face are normal but she has difficulty initiating sentences and she is unable to write her name. The most likely cause of this patient’s condition is an occlusion of which of the following vessels?
- A. Right vertebrobasilar artery
- B. Right middle cerebral artery
- C. Left posterior cerebral artery
- D. Left anterior cerebral artery (Correct Answer)
- E. Right anterior cerebral artery
Vascular Surgery Explanation: ***Left anterior cerebral artery***
- Stroke in the **left anterior cerebral artery (ACA)** territory typically causes **contralateral leg weakness** (right leg in this case) and **urinary incontinence** due to involvement of the paracentral lobule.
- The patient's difficulty writing her name (agraphia) and initiating sentences (transcortical motor aphasia, which can manifest as difficulty initiating speech) is consistent with damage to the supplemental motor area in the dominant (left) hemisphere, provided by the ACA.
*Right vertebrobasilar artery*
- Occlusion of the vertebrobasilar artery typically presents with a wide range of symptoms including **vertigo**, **ataxia**, **dysarthria**, and bilateral or alternating sensory/motor deficits.
- It would not selectively cause isolated right leg weakness, urinary incontinence, and dominant hemisphere language difficulties without other brainstem or cerebellar signs.
*Right middle cerebral artery*
- A stroke in the **right middle cerebral artery (MCA)** would cause **left-sided deficit**, not right-sided.
- Although it can cause motor and sensory deficits, it typically affects the arm and face more than the leg, and would not cause the specific language deficits of the dominant hemisphere seen here.
*Left posterior cerebral artery*
- Occlusion of the **left posterior cerebral artery (PCA)** typically leads to issues like **contralateral homonymous hemianopia**, visual field defects, and potentially memory impairment or alexia without agraphia if the splenium of the corpus callosum is involved.
- It directly affects posterior brain regions, so it would not cause the anterior cerebral artery specific symptoms such as prominent contralateral leg weakness, urinary incontinence, or the described language difficulties.
*Right anterior cerebral artery*
- Occlusion of the **right anterior cerebral artery (ACA)** would cause **left leg weakness** and **left-sided sensory deficits**, not the right-sided deficits observed in this patient.
- While it could cause urinary incontinence, the combination of right-sided weakness and dominant hemisphere language deficits points against a right ACA occlusion.
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