MCQs Vascular surgery
1
Which of the following is true with regard to investigation of thoracic aortic dissection?
A
Aortography remains the gold standard investigation.
B
CXR is normal in up to 20% of patients.
C
Transthoracic echocardiography is an excellent diagnostic imaging technique.
D
Aortography has significantly higher accuracy than spiral CT with contrast.
Answer
2
A 56 yo female with chronic renal failure on haemodialysis presents with general malaise and nausea. She is febrile with a tender right forearm fistula. Which of the following is TRUE?
A
Thrombophlebitis in this setting is a leading cause of death.
B
Blood cultures should be taken from the fistula site as well as peripherally, as they have a higher rate of positive culture.
C
Pseudomonas species are a common cause of fistula infection.
D
Alternative haemodialysis access is not a priority in this patients initial management.
Answer
3
Regarding vascular malformations of the head and neck, which of the following is TRUE?
A
Secondary rupture after treatment occurs mostly within the first 3 months.
B
Hypernatraemia may complicate aneurysmal recovery.
C
The rebleed rate after rupture is 10% per year.
D
85% of saccular aneurysms occur in the anterior circulation.
Answer
4
Which of the following is NOT a recognised cause of carotid or vertebral artery dissection?
A
Ehlers-Danlos syndrome
B
Autosomal dominant polycystic kidneys
C
Atherosclerosis
D
1 degree relative with aortic dissection
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Answer
5
With regards to ruptured abdominal aortic aneurysm, which of the following statements is FALSE?
A
Ruptured AAA is initially misdiagnosed in up to 30% of presentations.
B
90% are atherosclerotic in origin
C
50% are palpable
D
Mortality rate of 45% for those who reach hospital alive.
Answer
6
Which of the following is TRUE with regard to burns
A
IV cannula should never be inserted into non burned tissue
B
Parkland formula uses N/S only
C
Parkland formula uses N/S and Dextrose
D
3ml/kg/percent burn + maintenance fluids should be administered over 24hrs
Answer
7
With regards to acute arterial occlusion, which of the following is FALSE?
A
Thrombotic arterial occlusion is often associated with other signs of peripheral vascular disease.
B
90% of emboli are of cardiac origin.
C
Irreversible changes begin to occur within 4-6 hours after acute arterial occlusion
D
Heparinisation should be administered immediately, except if the patient is proceeding urgently to theatre.
Answer
8
With regards to abdominal aneurysms, all statements are true EXCEPT:
A
Splenic artery aneurysms are the 2 commonest
B
Hepatic artery aneurysms are associated with IVDU
C
Normovolaemia is the aim of resuscitation
D
Risk of rupture of AAA outweighs elective surgical risk when >5cm
n
Answer
9
With regards to investigations for SAH, which statement is TRUE:
A
Absence of xanthochromia excludes SAH
B
Non contrast CT is >95% sensitive
C
MRI angiography is less reliable than cerebral angiography
D
A mild troponin rise is seen in 20%
Answer
10
With regards to sutures for wound closure
A
Absorbable sutures are made from either collagen or synthetic polymers
B
The swage of the needle is the best site for holding with the needle holder
C
Silk sutures have high tensile strength and tissue reactivity
D
Chromic gut sutures degrade over 3 to 4 weeks
Answer
11
With regards to solutions used for wound cleaning
A
Normal saline has a mild antiseptic action
B
Peroxide is bacteriocidal to aerobic bacteria only
C
The bacteriocidal effect of Povidone – Iodine 10% occurs because of release of free iodine into the wound
D
Chlorhexidine 0.1% aqueous is bacteriocidal for anaerobic bacteria
Answer
12
Re imaging in thoracic dissection, which of the following is TRUE
A
Aortography is more sensitive than CT
B
Low pre test probability and a negative CT has a 10% false negative rate
C
A negative CT angio excludes a dissection with a high pre test probability
D
Further imaging should be considered with a high pre test probability and negative initial imaging
Answer
13
The highest likelihood ratio for a patient with suspected thoracic dissection is
A
Widened mediastinum on CXR
B
Tearing or ripping pain
C
Focal neurological deficit
D
Sudden chest pain
Answer
14
Real time CXR (ie on the floor) sensitivity for thoracic dissection is approximately
A
Over 90%
B
80%-90%
C
70%-80%
D
Less than 60%
Answer
15
In regards to arterial occlusion in limbs
A
Embolic Cause most likely if prior claudication
B
Sensorimotor deficit is an indication for urgent management
C
A non palpable unilateral dorsalis pedis pulse confirms presence of peripheral vascular disease and increased risk of acute occlusion
D
A pale, pulseless, paralysed limb is an indication for admission for anticoagulation
Answer
Answers
1.
B
2.
E
3.
E
4.
C
Dunn, p866
5.
C
Dunn. 75% are palpable
6.
E
7.
D
Dunn, Cameron.
8.
C
Dunn
9.
D
Dunn
10. A
Cameron et al Paediatrics p95-6
11. C
Cameron et al p 110
12. D
A F-aortography can miss intramural haematomas B F-0.2% false negative, can exclude C F D T E F
Diagnostic accuracy of
Transoesophageal Echocardiography, Helical Computed Tomography, and Magnetic Resonance Imaging for Suspected Thoracic Aortic Dissection. Systematic Review and Meta-analysis. Shiga et al, Arch Intern Med 2006: 166: 1350-1356 13. C
A F-LR 2.0 B F-LR 10.8 C T-LR 33 D F-LR 1.6 E F-LR 1.6 Does This Patient Have an Acute thoracic Dissection? Klompas et al, 2002,JAMA 287(17);2262-72
14. E
Answer-I think E after reading the papers below I think but many don’t agree One study 88.9% but flaws-43 patients, reviewed by radiologists who knew that approximately half the patients had AD
Remaining papers sensitivity
approximately 50% to 90% but vast majority are unblinded, retrospective reviews of patients with known dissection, not all studies looked at the same radiographic findings, and viewed by radiologists not ED physicians 15. B
Dunn A – Thrombotic cause much more likely B – Needs blood restored within 3-4 hours C – Normal finding in 10% of population D – Patient needs more than anticoagulation (embolectomy, bypass or thrombolysis) E – Alternatives are angiography/plasty, thrombolysis
