Aortic Aneurysm Flashcards
What is AAA?
- expansile mass
- dilation of aorta >1.5 x expected
- > 3cm diameter
- most found below the renal arteries
- m>f
Presentation of AAA
Ruputured:
- new abdo/back pain
- CDV collapse
- syncope
Unruptured:
-asymptomatic
-incidentally detected
-
Diagnosis
- USS first line
- CTA or magnetic resonance angiography used for anatomical mapping to assist with operative planning
- ruptured = urgent surgery
- unruptured = surveillance
Complications for AAA treatment
- acute kidney injury
- limb ischaemia
- spinal cord ischaemia
- anastomotic pseudoaneurysm
- graft infection
- graft limb occlusion
- distal embolisation
Aetiology of AAA
- atherosclerotic disease
- altered tissue metalloproteinases may diminish the integrity of the arterial wall- loss of collagen, elastin
- smoking biggest rf
- diabetes protects against the growth and enlargement of AAA
Types of AAA
1) Congenital: degeneration accelerated in patients with bicuspid aortic valves and Marfan syndrome
2) Infectious - infection of the aortic wall (mycotic aneurysm)
3) Inflammatory- abnormal accumulation of macrophages and cytokines in diseased tissue
Case Histories of AAA
1) A 65-year-old man presents to his local aneurysm surveillance team for a screening ultrasound scan. He has been feeling well and in his usual state of good health. His medical history is notable for mild hypertension and he has a 100-pack-year smoking history. On ultrasound an infrarenal AAA is identified.
2) A 55-year-old man with a history of hypertension (well controlled with medication) and cigarette smoking presents to his general practitioner with a 2-day history of constant and gnawing epigastric pain. The pain has been steadily worsening in intensity. He says the pain radiates to his lower back and both groins at times. There is a palpable pulsatile mass just left of midline above the umbilicus. He is immediately referred to a regional vascular service for definitive management, but during transfer becomes hypotensive and unresponsive.
Other presentations of AAA
AAA Triad: pulsatile abdo mass, hypotension, abdo/back pain
- fever
- weight loss
- elevated erythrocyte sedimentation rate suggest inflammatory AAA
- elevated CRP
- Hx of arterial trauma, IV drug misuse, infetcion, impaired immunity
- osteomyelitis, anaemia,
Investigations for AAA
- aortic USS
- cross match
- clotting screen
- erythrocyte sedimentation ESR/ CRP
- FBC
- blood cultures
- CTA
- MRA/MRI
- PET-CT
Other differentials
- diverticulitis
- ureteric colic
- IBS
- IBD
- Appendicitis
- Ovarian torsion
- GI haemorrhage
- Mesenteric artery aneurysm/acute occlusion
Screening for AAA?
-routine screening for m>65 years
3-4.4 cm = annual surveillance programme
4.5-5.4 = 3 month SP
> 5.5 = refer to vascular surgeon
Treatment algorithm for AAA
1) Ruptured AAA
- Urgent surgical repair:- bedside aortic USS; leave referring unit <30 mins, EVAR- endovascular aneurysm repair, blood transfusion if Hb < 100g/L
-Resus measures; oxygen, IV access, arterial/urinary catheter, hypotensive resus (SBP of 90-120)
- PeriOp antibiotic therapy- prophylactic antibiotics to cover gram -+
- Analgesia
- VTE prophylaxis; for surgical repair- enoxaparin OR heparin
2) Symptomatic but unruptered AAA
- urgent surgical repair
- PeriOP antibiotic therapy
- analgesia
- VTE prophylaxis
3) Incidental finding of asymptomatic AAA <5.5 & not rapidly growing
- surveillance annually or 3 monthly
- aggressive CDV risk management- smoking, antiplatelet (aspririn/clopidogrel), lipid lowering, antihypertensives
4) Incidental finding of asymptomatic AAA >5.5 & rapidly growing
- elective surgical repair
- pre-op CDV risk reduction
- peri-op antibiotic therapy
- analgesia
- VTE prophylaxis- LMW-Heparin, or mechanical- anti-embolism stockings or intermittent pneumatic compression; enoxaparin
Emerging treatment for AAA
- Doxycyline- inhibits MMPs
- Metformin
- GLP-1 receptor agonists and DPP-IV inhibitors
- EVAS- endovascular aneurysm sealing
Complications of AAA (repair)
- abdo compartment syndrome
- ileus, intestinal obstruction, ischaemic colitis
- acute kidney injury
- post-implantation syndrome
- amputation due to limb ischaemia
- spinal cord ischaemia
- impaired sexual function
- anastomotic pseudoaneurysm
- aortic neck dilation
- graft infection
- ureteric obstruction
- functional gastric outlet obstruction
- graft limb occlusion
- endoleak
- distal embolisation
