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Y4: Vascular Surgery > Aortic aneurysm > Flashcards

Flashcards in Aortic aneurysm Deck (24)
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What is an aneurysm defined as?

  • AAA dilatation > 1.5 times normal AP diameter 
  • True aneurysm: dilatations involve all layers of the arterial wall
  • False (pseudo)aneurysm: blood collection in outer layer (adventitia) only 


What are the two forms of aneurysms?

  • Fusiform (most AAAs)
  • Sac-like (Berry aneurysms)


Causes of aneurysms?

  • Atheroma
  • Infections
  • Inflammatory 
  • Connective tissue disorders 


Complications of aneurysms?

  • Fistulae
  • Rupture
  • Thrombosis/embolism
  • Pressure on other structures 


Screening of aneurysms?

  • Men offered abdominal US from 65-75
  • Selective screening based on risk factors


Symptoms & signs of a ruptured AAA?

  • Abdominal pain radiating to the back
  • Expansile abdominal mass (expands and contracts)
  • Shock


Describe an unruptured AAA?

  • >3cm diameter
    • Normal after 50 yrs(Men 1.7cm, women 1.5cm)
  • Failure of elastic proteins within the ECM 
  • Often asymptomatic and incidental finding on abdominal exam


What makes AAA rupture more likely?

  • Smoking
  • Female sex
  • Hypertension
  • Positive family history 


Describe surgery for unruptured AAA?

  • Surgery for:
    • Aneurysms >5.5cm, expanding >1cm/yr, symptomatic
  • Stenting (EVAR) procedure 


Describe overview of open AAA repair?

  • Laparotomy, dissection to the AA
  • Clamping of the artery below renal arteries and in the iliac arteries 
  • Aneurysm is opened:
    • IMA and lumbar arteries ligated
    • Tube or bifurcated graft are sutured into the aorta to exclude the aneurysm
  • Aneurysms sac is sutured over the graft to reduced infection rates 


Describe EVAR?

  • Endovascular stent inserted via the femoral artery
  • Less mortality than major surgery but higher graft complications
    • eg endoleak: blood may leak into aneurysm


Complications of open AAA repair?

  • Intra-operative complications:
    • Haemorrhage
    • Injury to surrounding structures
  • Early complications:
    • Infection
    • Blood clots
  • Late complications:
    • Hernia 
    • Adhesions


Describe the emergency management of a ruptured abdominal aneurysm?

  • Inform vascular surgeon, experienced anaesthetist
  • Crossmatch blood, catheterise
  • Insert 2 large bore cannulase
    • Treat shock with O rhesus negative blood
  • Prophylactic antibiotics eg co-amoxiclav 
  • Surgery:
    • Clamping of aorta above the leak
    • Tube graft inserted
    • If iliac aneurysm: trouser graft, leg attached to each iliac artery 


What infectious disease is an ascending aortic aneurysm associated with?

Tertiary syphilis 


Name another cause of an adominal pulsatile mass?

  • Tumour of pancreas or stomach
    • Aortic passess between these structures 


Abdominal aorta anatomy 


Pathophysiology of AAA?

  • Obliteration of collage and elastin in the media and adventitia 
  • Smooth muscle loss
  • Infiltration of lymphocytes and macrophages 


What are the different classifications of AAA?

  • Congenital
    • Accelerated in patients with Biscupid AV or Marfans
  • Infectious
    • Staphylococcus and salmonella are most common causes
  • Inflammatory


Common presentations of AAA


Differentials for AAA?

  • Diverticulitis
    • No pulsatile abdominal mass
    • CT scan shows normal aorta
  • Irritable bowel syndrome (IBS)
    • Bloating, stool frequency
    • More common in women 
  • Appendicitis 


What is the most common site for aneurysmal disease required treatment?

Infrarenal aorta 


What reasons might a patient survive a ruptured AAA?

  • Bleed into retroperitoneum which tamponades the leak
  • Intense vasoconstriction of nonessential circulatory beds
  • Development of an intense prothrombotic state
  • BP drops which limits blood loss 


What must be screened for in patients with AAA?

  • Popilteal aneurysms
    • Ultrasound 


Describe the management of popliteal aneurysms?

  • Exclusion of the aneurysm
  • With bypass using the long saphenous vein