Aneurysms Flashcards
Aneurysm definition
Permanent and irreversible localised dilation of a blood vessel
- At least 50% more than expected diameter.
Ectasia
Permanent, irreversible localised dilation of less than 50% of normal diameter
Arteriomegaly
Diffuse arterial enlargement without discrete aneurysm.
Most common locations of aneurysm
> 90% infra-renal abdominal
Aortic arch
Thoracic arch
Supra-renal abdominal aorta
Aetiology of aneurysms
Degenerative
Familial
Vasculitic
Connective tissue abnormality
Infective (mycotic)
Epidemiology of aneurysms
- Age
- Ethnicity
- Sex
M:F= 4:1
Familial, M:F= 2:1
Afro-Carribean= 0.53
Aneurysm classifications
True
- Dilation involves all layers
- Fusiform (AAA), saccular (berry)
False (Pseudo)
- Collection of blood that communicates with lumen. Between tunica media and the tunica adventitia.
- Cause: puncture, cannulation.
Dissection
- Dilation caused by blood separating apart the media
- Forms a channel with vessel wall.
Congenital causes of aneurysms
Autosomal dominant polycystic kidney disease (ADPKD)
- Berry aneurysms
Connective tissue abnormalities:
- Marfan’s
- Ehler’s danlos
Complications of aneurysms
Rupture
Thrombosis
Distal emoboli
Pressure
- DVT
- Oesophagus
- Nutcracker syndrome
Fistula
Nutcracker syndrome
Pressure complication of aneurysms
Compression of the left renal vein between the aorta and the superior mesenteric artery.
AAA presentation
Asymptomatic
Back/ umbilical pain radiating to groin
Acute limb ischaemia
Distal emboli: blue toe syndrome
Acute rupture:
- Expansile adominal mass
- Shock
- Severe abdo pain, radiating to back/ flank
Investigations for AAA
Imaging
- USS: monitors growth, identifies aneurysms
CR/MRI= gold standard
Management of AAA
- Conservative
- Open repair
- Endovascular (EVAR)
Screening for AAA
Screening occurs as it’s fairly common (5% males >65) with very high mortality rate if it ruptures (90%)
Men screen at 65
Conservative management of AAA
- Manage cardiovascular risk factors
- BP, cholesterol
Can be monitored if diameter <5cm.
- 3-4.4cm= yearly monitoring
- 4.5-5.4= 3 monthly
Endovascular repair of AAA
- Incision
- Anaesthesia
- Complications
- Post-op
- Mortality
Small groin incisions made
- Under local or regional anaesthetics
Stent graft, complications
- Migration of graft
- Endoleak
- Graft limb occlusion
Post-op
- Surveillance
- Re-interventions risk
- Risk of rupture higher than open
Mortality= 1-2%
Reasons for open> EVAR
Unusual anatomy
Cost (cheaper)
Large/ symptomatic juxa-renal aneurysm
Emergency
Patient preference
Pathology of AAA
- Dize of dilation
- Location
Dilation >3cm
Location
- >90% infrarenal
- 30% iliac arteries.
Surgical emergency management of AAA rupture
- High flow O2
- Large bore cannulae in each ACF
- Keep BP <100
- Give fluid if shocked
- Blood taken: FBC, U+E, clotting, amylase, Crossmatch. - Haemorrhage protocol + call vascular surgeon, anaesthesia
- Analgesia
- Antiobiotic prophylaxis
- Urinary catheter, CVP line
- Stable= CT/US
Thoracic aortic dissection
- Aetiology
90%–> Atherosclerosis, HTN
Thoracic aortic dissection
- Aetiology
90%–> Atherosclerosis, HTN
Rarer
- Connective tissue disorders: Marfan’s, Ehler’s danlos
- Vit C def
Thoracic aortic dissection
- Presentation
- Include distal and proximal propagation.
Sudden onset of tearing chest pain
- Radiates to back
Tachycardiac, HTN
Distal propagation (occlusion of sequential branches)
- Left hemiplegia
- Unequal arm pulses and BP
- Paraplegia (anterior spinal art.)
- Anuria
Proximal propagation
- Arotic regurg
- Tamponade
Classifications of thoracic aneurysms
Stanford classifications
Type A: Proximal (70%)
- Ascending aorta with/ without might involved descending
- Higher mortality due to cardiac complications.
Type B: Distal (30%)
- Descending aorta only
- Usually managed conservatively
Investigations of thoracic aneurysm
Bloods
- Xmatch
- FBC, U+E
- Clotting
- Amylase
ECG
- Excludes MI
- May show ischaemia if coronary ostia involved.
Imaging
- CXR
- CT/MRI: if HD stable
- TTE/ TOE: if HD unstable
Management of Thoracic anuerysm
- Analgesia
- BP management
- Beta-blocker: Labetalol/ Esmolol
- BP ket at 100-110 - Type A: Open repair
Type B: Conservative . Surgery if pain persistent/ complications.
Indications for elective repair of AAA
- Symptomatic aneurysm
- Aneurysm growing >1cm/ year
- Diameter >5.5cm
