Give examples of common anatomical sites at which aneurysms occur. Why do aneurysms occur at such sites?
Common sites:
- infrarenal aorta
- popliteal
- femoral
- iliac
Occur at sites of bifurcation due to tumultuous blood flow
Explain the difference between true and false aneurysms.
True = involves all 3 layers of vessel wall, occurs in atherosclerosis False = collection of blood in the tunica adventitia that communicates with the lumen, occurs in situation such as penetrating trauma
What are the S+S of aortic aneurysms?
- central abdo pain radiating to the back
- severe presentation = sudden collapse
- subacute = persistent severe central abdo pain
- patient may present with shock (hypotensive + tachycardic)
- patient will usually have a history of CV disease
What are the indications for surgical intervention in aortic aneurysm disease?
- if the AP diameter is >5.5cm in individuals
- symptomatic AAA
- if it is growing rapidly in size (>0.5cm over 6 months)
What are the differential diagnoses for an epigastric mass?
- Skin + soft tissue: sebaceous cysts; lipoma; sarcoma; herniae
- GIT: hepatomegaly; carcinoma of stomach; carcinoma of pancreas; pancreatic pseudocyst
- Vascular: AAA; retroperitoneal lymphadenopathy
- Ruptured AAA: acute abdomen; acute pancreatitis; perforation; renal colic; biliary colic; inferior MI
What are the risk factors for arterial aneurysms?
- smoking
- hyperlipidaemia
- COPD
- atherosclerosis
- hypertension
- central obesity
- FHx
- increasing age
- male (prevalence)
- CT disorders
What is the first line investigation for a suspected AAA?
Abdominal US (unless aneurysm is close to renal arteries - then use CTA); threshold for diameter ≥3 cm
What might blood tests in a patient with AAA show?
- ESR/CRP: elevated
- FBC: relative anaemia and leukocytosis (if infectious AAA)
- Blood cultures: if infectious AAA
How should asymptomatic aneurysms be monitored?
- 3.0-4.4 cm = abdo US every 2 years
- ≥4.5cm = abdo US every 3-6 months (the bigger it is, the more often it is monitored)
What are the potential complications of aneurysms?
- death (shock, MI, renal failure)
- rupture
- thrombosis
- embolism
- pressure
- infection
- fistulae
Describe the process of open AAA repair?
- Expose AAA
- Open AAA
- Sew in artificial graft
- Close AAA
What are the benefits and disadvantages of open AAA repair?
Benefits:
- reintervention is unlikely to be necessary
- graft is more durable
Disadvantages:
- infection
- significant abdominal decisions
- 30-90 minute cross clamp of aorta
- contraindicated in people with previous surgery
- long hospital stay
What are the potential complications of open AAA repair?
- renal failure
- distal embolisation
- MI
- graft infection
- spinal cord injury
- impotence
- embolus
- ischaemia of the mesentery, limb or spine
Describe the process of endovascular aneurysm repair (EVAR).
- Graft is introduced via femoral artery to the aneurysmal site and positioned in the normal diameter artery above and below the aneurysmal section
- It is uncoiled
- If the aneurysm is close to the aortic bifurcation then the stent must go down both iliac arteries
- An angiogram is performed to check the stent is correctly positioned
What are the benefits and disadvantages of EVAR?
Benefits:
- minimally invasive
- lower mortality rate
- shorter recovery time
- better functional outcome than open AAA repair
Disadvantages:
- endoleak
- stent/graft migration
- stent/graft relocation
- reintervention requirement
What are the potential complications of EVAR?
- damage to surrounding vessels or organs by instruments
- endoleak
- renal failure
- groin wound infection
- groin haematoma
- spinal cord injury
- limb ischaemia
Describe the S+S of a patient presenting with a leak or rupture of an AAA.
Symptoms:
- sudden onset epigastric and/or back/groin pain
- history of sudden collapse and transient hypotension
- history of AAA
Signs:
- cardinal signs: unexplained rapid onset of hypotension, pain and sweating
- pulsatile abdo mass
Describe the S+S of a patient presenting with a leak or rupture of a thoracic aortic aneurysm.
- present with chest pain indistinguishable from MI
- can have haemoptysis
- diagnosis usually made post-mortem as rupture causes cardiac tamponade and death
What is the acute management for an AAA?
- large bore IV access ASAP
- Group and save and bloods
- theatre ASAP
- secure proximal aortic control without disturbing any tamponade effect provided by extra aortic structures or haematoma
- resuscitation of hypovolaemic shock (fluids, high flow O2 non-rebreathing mask)
- repair of leak or rupture with a prosthetic graft/stent
