Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine - Year 2 > The vascular system and stroke - Aneurysms and dissections > Flashcards

The vascular system and stroke - Aneurysms and dissections Flashcards

1
Q

Describe the criterias that must be fulfilled before a referral to the vascular surgeons for AAA is made

A
  • Patient is symptomatic
  • Patient is symptomatic with AAA > 5.5cm
  • Patient is asymptomatic with AAA >4.0cm and has grown >1cm in 1 year
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the management of an AAA, if the size is:

a) 3-4.4cm
b) 4.5-5.4cm
c) >5.5cm

A

a) Offered yearly repeat ultrasound
b) Offered repeat ultrasound every 3 months. Give lifestyle advice. Refer to vascular service, to be seen within 12 weeks
c) surgery generally recommended and refer to vascular surgeon within 2 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the screening for AAA in the UK

A
  • All men are invited for screening ultrasound scan in their 65th year
  • Older men can self-refer
  • < 3cm = discharged
  • 3-4.4cm = offered yearly repeat ultrasound. Give lifestyle advice. Refer to vascular service, to be seen within 12 weeks.
  • 4.5-5.4cm = offered repeat ultrasound every 3 months. Give lifestyle advice
  • =/>5.5cm = refer to vascular surgeon within 2 weeks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the definition of ‘aneurysm’ ?

A

A localised dilation of an artery with at least 50% increase in diameter compared to the expected normal diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is an ectasia?

A

A localised dilation less than 50%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the two broad types of aneurysms?

A

True aneurysm and false/’pseudo’ aneurysm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the difference between a true and false aneurysm

A

True aneurysm - involves all 3 layers of arterial wall

False aneurysm - blood flow outside of normal layers of arterial wall. The wall is composed of compressed surrounding tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

True aneurysms can generally classified by shape and size. Describe the two types of true aneurysms.

A

Saccular - are spherical outpouchings (involving only a portion of the vessel wall); they vary from 5 to 20 cm in diameter and often contain thrombus

Fusiform - involve diffuse, circumferential dilation of a long vascular segment; they vary in diameter (up to 20 cm) and in length, and can involve extensive portions of the aortic arch, abdominal aorta, or even the iliac arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name 5 locations where you would typically find a true aneurysm

A
  • Abdominal aorta and iliac
  • Popliteal
  • Femoral
  • Thoracic aorta
  • Thoracoabdominal aorta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name 3 locations where you would typically find a false aneurysm

A
  • Radial
  • Femoral
  • Anatomic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the mechanisms of aneurysms

A
  • Expansion thus compressing/eroding adjacent structures
  • Rupture
  • Distal embolism
  • Thrombosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the risk factors of AAA

A
  • Male
  • 65+ years
  • Smoking
  • 1st degree relative with AAA
  • Atherosclerotic disease
  • Connective tissue disorders (Marfan’s and Ehlers Danlos)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the presentation of AAA

A
  • Most are symptomatic
  • Pain and/or tenderness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

a) What is blue toe syndrome?

b) What does it suggest?

A

a) Ischaemic toes with palpable foot pulses

b) Suggest micro-embolisation from atherosclerotic plaque or aneurysm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the presentation of a ruptured AAA

A
  • Severe abdominal pain that may radiate to the back or groin
  • Haemodynamic instability - tachycardia and low BP hypovolemia - loss of more than 15% fluid in body leading to low BP)
  • Pulsatile and expansile mass in the abdomen
  • Collapse
  • Loss of consciousness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the presentation of an AAA embolization

A
  • Acute limb ischaemia (6 P’s)
  • Blue toe syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the rules of driving and having an AAA

A
  • Car drivers can continue if < 6cm, must notify the DVLA between 6-6.4cm and must stop when =/> 6.5cm
  • Bus/lorry driver must notify DVLA if <5.5cm and must stop when =/> 5.5cm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The severity of the aortic aneurysm depends on the size. Describe the 4 different sizes

A

Normal: less than 3cm
Small aneurysm: 3 – 4.4cm
Medium aneurysm: 4.5 – 5.4cm
Large aneurysm: above 5.5cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the management of an AAA

A

Antiplatelet and statins to reduce risk of adverse cardiovascular events

No medications are currently proven to reduce rate of expansion

Smoking cessation

Treatment of hypertension, diabetes and hyperlipidaemia

< 3cm = discharged

3-4.4cm = offered yearly repeat ultrasound. Give lifestyle advice. Refer to vascular service, to be seen within 12 weeks.

4.5-5.4cm = offered repeat ultrasound every 3 months. Give lifestyle advice

=/>5.5cm, symptomatic, diameter growing more than 1cm = Refer to vascular surgeon within 2 weeks for surgery (open repair/EVAR recommended

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe the investigations for an AAA

A

Bedside
- Observations/Monitoring
- ECG
- Urine dip

Bloods
- FBC
- U&E
- LFT
- Clotting screen
- ABG/VBG
- Group and Save / Crossmatch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe the imaging modalities for AAA

A

Abdominal USS (1st line)

MRI/CT: Used for pre-operatively in the elective setting to allow for surgical planning. May be used in the acute setting in suitably stable patients.

AXR (not a sensitive test but may be ordered in the work-up of a patient presenting with abdominal pain)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the two surgical options to treat AAA?

A

Open repair (OR)

Endovascular aneurysm repair (EVAR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the open repair (OR) process of AAA

A
  • Open repair involves a laparotomy incision in the midline from the xiphisternum to pubic symphysis under a general anaesthetic
  • The aorta is identified in the retroperitoneum
  • The aorta is clamped above the aneurysm and usually below the renal arteries
  • The iliac arteries are clamped below the aneurysm.
  • The aneurysm sac is then opened
  • A tubular graft graft made from polyester is sewn to the aorta inside the aneurysm sac
  • The sac is then sewn closed over the graft to prevent it coming into contact with the small bowel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What shape will the graft be in open repair if the aneurysm involves the iliac arteries

A

Bifurcated (Trouser-shaped)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the complications of open repair

A
  • Death (2%)
  • Bleeding
  • Ischaemia
  • Cardiac, respiratory and renal failure
  • Wound infection, dehiscence (burst open) and incisional hernia (due to wound weakening)
  • Adhesive small bowel obstruction
  • Graft infection and aortic-enteric fistula (1%)
26
Q

Describe endovascular aneurysm repair (EVAR) in AAA

A
  • EVAR involves two small groin incisions under a general, regional or local anaesthetic
  • Wires are fed into the aorta from the femoral arteries
  • The collapsed stent graft is housed in a delivery sheath and is fed over the wires into the aorta
  • The components of the stent Graf are carefully positioned in the aorta and assembled under x-ray guidance
27
Q

Describe the complications of EVAR

A
  • Death (<1%)
  • Contrast and radiation toxicity in large doses
  • Wound haematoma, seroma, infection
  • Damage to access vessels
  • Slipping, kinking, thrombosis, endoleak and rupture
  • Life-long surveillance required with ultrasound and CT scans
28
Q

Describe what an endoleak is

A
  • An endoleak is when blood is flowing outside the stent graft but inside the aneurysm sac
  • it can be low pressure or high pressure
  • May spontaneously seal with time
  • May cause sac expansion or rupture
29
Q

Describe the difference between a type 1 and 2 endoleak

A

Type 1 endoleak
- Poor seal between graft and neck or iliacs
- Usually, high pressure blood
- Always concerning - high risk of rupture
- Usually treated
- Uncommon

Type 2 endoleak
- Back bleeding lumbar arteries or IMA
- Usually, low pressure
- Only concerning if sac is expanding
- Low risk of rupture
- Usually kept under surveillance
- May resolve spontaneously
- Common

30
Q

Compare open repair vs EVAR

A
31
Q

Discuss if open repair or EVAR better is better

A
  • Open repair is better for younger, more fit patients
  • EVAR is better for older, less fit patients
  • EVAR does not increase overall life expectancy in patients not fit for open repair
  • Guidelines suggest an open repair must be offered to all patients if not contraindicated. If contraindicated then EVAR
32
Q

Describe the management of a ruptured AAA

A
  • Assess age, co-morbidities, frailty, patient and family wishes, advance decisions, QoL and functional status to help decide whether surgery is appropriate
  • Bloods for GBC, U&E, LFT, glucose, amylase, clotting and cross match (activate massive transfusion protocol)
  • ECG
  • Large bore IV cannula and urinary catheter
  • Fluid resuscitation to maintain systolic BP 70-90 mmHg (‘permissive hypotension’)
  • EVAR for stable and anatomically suitable patients
  • Open repair for unstable patients and those anatomically unsuitable for EVAR
33
Q

Not every AAA is suitable for EVAR. The anatomy of the aneurysm must be favourable. The stent graft needs to obtain a seal in the neck of the aneurysm and in the iliac artery. Describe the ideal anatomy of the infrarenal neck and iliac access.

A

Infrarenal neck
- Length =/> 15mm
- Diameter =/< 30mm
- Shape - cylindrical not conical in shape
- Angulation - not too angulated

Iliac access
- Patency - patent and not occluded
- Diameter - a reasonable size
- Tortuosity - not too tortuous

34
Q

If a patient has a popliteal aneurysm (PAA). What are the chances that they have an AAA?

A

50%

35
Q

Describe the indications of surgery for a popliteal aneurysm

A

Asymptomatic
- Diameter > 2-3cm
- Significant lining thrombus

Symptomatic
- Thrombosis (causing ALI)
- Distal embolization (causing chronic limb ischaemia or blue to syndrome)
- DVT (from compression of popliteal vein)

36
Q

What are the treatment options for a popliteal aneurysm

A

Exclusion bypass

Endovascular treatment - stent grafting/thrombolysis

37
Q

Describe the exclusion bypass of a popliteal bypass

A
  • The popliteal aneurysm is ligated above and below to exclude it from the circulation
  • A femur-popliteal bypass is then performed to restore blood flow to the foot
38
Q

What are the 3 types of false femoral aneurysms

A
  1. Iatrogenic false aneurysm
  2. Non-specific aneurysm
  3. Anastomotic aneurysm
39
Q

What must you exclude in patients with a femoral aneurysm?

A

Patients presenting with a femoral aneurysm should have an AAA excluded by ultrasound scan

40
Q

Describe the treatment of false radial femoral aneurysms

A
  • Spontaneous thrombosis
  • Ultrasound guided compression
  • Thrombin injection
  • Surgery
41
Q

a) Describe the complications of juxtarenal, suprarenal, thoraco-abdominal and thoracic aneurysms

b) Describe the treatment

A

a) Death, stroke, paraplegia

b)
Open repair - thoracotomy +/- laparotomy

Endovascular repair - stent/graft +/- fenestrations or branches

Hybrid repair - laparotomy, stent graft + visceral bypasses

42
Q

What is an aortic dissection?

A
  • Tear in the intima
  • Blood enters the arterial wall itself (between the the intima and media), as a haematoma
  • This creates a false lumen full of blood within the wall of the aorta.
43
Q

There are two classification systems for aortic dissections. Name the two classifications

A
  1. The Stanford system
  2. The DeBakey system
44
Q

Describe the Stanford system of classification for aortic dissections

A

Type A – affects the ascending aorta, before the brachiocephalic artery

Type B – affects the descending aorta, after the left subclavian artery

45
Q

Describe the Debakey system of classification for aortic dissections

A

Type I –Involves the ascending aorta, dissection extends into arch and beyond

Type II – isolated to the ascending aorta

Type IIIa – Involves the descending thoracic aorta (distal to left subclavian artery, proximal to coeliac artery)

Type IIIb – Involves the descending aorta and abdominal aorta

46
Q

Which type (Stanford system) of aortic dissection is most serious and why?

A

Type A - it affects that arteries that come of the aortic arch e.g., carotid arteries

47
Q

Describe the epidemiology of aortic dissections

A
  • More common in males than females - 3:1
  • Peak age 50-65 years
48
Q

List 8 risk factors of an aortic dissection

A
  • Hypertension
  • Atherosclerosis
  • Aortic aneurysms
  • Bicuspid aortic valve
  • Coarctation (a birth defect in which a part of the aorta, the tube that carries oxygen-rich blood to the body, is narrower than usual)
  • Coronary artery bypass graft (CABG)
  • Family history
  • Connective tissue - Ehlers-Danlos syndrome, Marfan’s syndrome
  • Pregnancy
  • High-intensity weightlifting
49
Q

Describe the presentation of an aortic dissection

A
  • Tearing chest pain radiating to back
  • Cardiovascular collapse
  • Pulse deficits (pulse in all limbs is different because dissection will affect blood flow from the branches of aorta)
  • Radio-radial (type A) or radio-femoral delay (type B)
  • Difference in BP between right and left arm > 20mmHg
  • Hypotension as dissection progresses
  • Neurological signs of stroke or paraplegia
  • Aortic regurgitation causing a diastolic murmer
  • Dyspnoea (ascending aorta –> aortic regurgitation –>CCF)
  • Neck/jaw pain (aortic arch)
    Horner’s (Type A dissection)
  • Interscapular pain (thoracic descending aorta)
  • Abdominal pain (abdominal descending aortic; mesenteric arteries)
  • Flank pain (renal arteries)
50
Q

Describe the investigation for an aortic dissection and the likely findings

A

Bedside observations
- ECG (ischaemic changes may be present if the dissection interferes with coronary blood flow)

Bloods
- FBC (leucocytosis may be present)
U&E
- LFT
- Clotting screen
- D-DIMER (may be elevated)
- Troponin (may be elevated in dissection or indicate the involvement of coronary vessels)
- ABG / VBG
- Group & Save / Cross-match

51
Q

Describe the imaging modalities for aortic dissections and some of the findings

A
  1. CT angiogram (diagnostic) - intimal flap, double lumen representing the true and false lumen, branch vessel perfusion
  2. Trans-oesophageal echocardiogram - if CT is unavailable. Has high sensitivity and specificity. May demonstrate pericardial effusion and aortic valve involvement.
  3. CXR - widened mediastinum, pleural effusion/haemothorax (carried out to rule out pulmonary causes of chest pain)
  4. MRI: Often used in the follow-up of patients with chronic dissections or following repair.
  5. ECG - May show ischaemia in specific territories if dissection extends into coronary arteries.
52
Q

a) Describe the management of stanford type A aortic dissection

b) Describe the management uncomplicated stanford type B aortic dissection

c) Describe the management if complicated stanford type B aortic dissection

A

a)
- Initial management is to give IV labetalol whilst patient is being transferred to theatre to slow progression of dissection
- Surgical aortic repair –> open surgery to replace ascending aorta +/- arch +/- aortic valve.
- May require re-implantation of coronary arteries or great vessels

b) Analgesia (IV morphine), strict control of BP with IV labetalol (beta blockers/alpha blockers or rate limited calcium channel blocker if contraindicated - aim to reduce HR and cardiac output to prevent propagation of dissection)

c) Thoracic endovascular aortic repair (TEVAR), with a catheter inserted via the femoral artery inserting a stent graft into the affected section of the descending aorta (to cover teat and promote thrombosis of false lumen)

53
Q

Describe the complications of an aortic dissection

A

Malperfusion (due to occlusion of branches in type A aorta dissection)
- Coronary -MI
- Carotid - stroke
- Spinal - parapelgia
- Renal - renal failure
- Mesenteric - acute mesenteric ischaemia
- Limb - ALI

Rupture

Aneurysmal dilation

54
Q

Emergency/urgent surgery is indicated in complicated type B dissection. What are the other indications of emergency/urgent surgery in Stanford type B dissections?

A
  • Intractable pain
  • Rupture or evidence of impending rupture
  • End-organ damage or limb ischaemia
  • Rapid progression
  • Marfan’s syndrome
55
Q

According to the Stanford classification. What type of aortic dissection is this? Describe the management

A
  • Type A
  • Surgical aortic repair –> open surgery to replace ascending aorta +/- arch +/- aortic valve.
56
Q

According to the Stanford classification. What type of aortic dissection is this? Describe the management

A
  • Type B
  • Uncomplicated: Strong analgesia (IV morphine) and IV labetalol
  • Complicated: Thoracic endovascular aortic repair (TEVAR)
57
Q

Describe the presentation of a popliteal

A
  • Acute limb ischaemia due to thrombosis
  • Chronic limb ischaemia due to embolisation
  • DVT due to compression of popliteal vein
  • Rarely rupture
58
Q

What must you also look for a patient has a popliteal aneurysm?

A

Contralateral popliteal aneurysm and AAA

59
Q

84 years male

PMH
- HTN
- Smoker
- High cholesterol
- Superficial bladder cancer

SH
- Independent ADLs
- CT done to investigate haematuria showed 7.2cm AAA

a) What are the risk factors for AAA?

b) How would you manage his AAA?

c) In the Neck MIP (maximum intensity projection) is the patient suitable for an EVAR?

A

a)
- Male
- Age > 65 years
- HTN
- Smoker

b)
- Ensure HTN well controlled
- Stop smoking
- Antiplatelet and statin to reduce cardiovascular risk
- His AAA is above the 5.5cm threshold for surgery
- Assess fitness for surgery
- Discuss risks and benefits of surgery
- Consider open repair and/or EVAR

c)
- The infra-renal neck is long, straight, not too wide and parallel-sided
- This is ideal for EVAR

60
Q

This a patient’s neck MIP. Are they suitable for an EVAR?

A
  • The infra-renal neck is very short
  • This is unsuitable for EVAR
61
Q
  • 51 years male
  • Sudden onset of chest and back pain, hypertensive (systolic 160)
  • PMH
  • HTN, non-compliant with medication

a) What are the differential diagnosis?

b) What investigations would you do?

A

a)
- Aortic dissection
- MI
- PE

b)
- CXR
- ECG
- ABG
- CT

62
Q

a) What type of aortic dissection does he have?

b) How would you manage his aortic dissection?

A

Type
- The dissection begins just after the origin of the left subclavian artery and is therefore a Type B

Management
- Analgesia
- Strict control of BP (systolic 100-120) using IV labetalol
- Surveillance
- TEVAR for ongoing pain, uncontrolled hypertension, malperfusion, aneurysmal dilatation, rupture

Medicine - Year 2 (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions