Abdominal Aneurysm Flashcards
Primary risk factors for a AAA
- First degree relative with known AAA
- Smoking
- Older age (typically 65+)
- CAD/Peripheral artery disease
- HTN, HLD, Atherosclerosis
- Male gender (80% of patients with AAA)
(Obviously there is more but those are the main ones)
Classic triad for AAA rupture presentation
Abdominal pain, pulsatile mass, and Hypotension - however a ruptured AAA can exist without any of these findings.
Note: If bleeding retroperitoneal then may not have hypotension because it tamponades.
Other symptoms may be: back or flank pain, N/V, painless Hematuria (if AV fistula), syncope
What size defines a AAA? What size requires repair?
Normal size infrarenal aorta: 2.0cm
> 3.0cm = AAA
> 5.0-5.5 —> repair
Besides rupture, what are some other complications of AAA?
- Embolization of microemboli —> blue toe syndrome and live do reticular is
- Aortoenteric fistula (esp. if Hx of prior repair)
- Aortovenous fistula (most commonly into the IVC) —> high-output CHF
Survival rate of a ruptured AAA decreases by __________ prior to arrival to the ED
1% per minute
Symptoms of non-ruptured AAA vs. ruptured AAA
Non-ruptured: maybe chronic non-specific or colicky abdominal pain
Ruptured: Usually constant, severe abdominal pain. Difficult to localize
What test to diagnose AAA and ruptured AAA?
- US has great sensitivity for AAA, but specificity for rupture is very low (like 4%). FAST will only show peritoneal bleeding but not retroperitoneal.
- CT noncontrast can diagnose and see the rupture too
- CT angiogram is best for pre-operative planning
Target BP for ressucitation of hypotension in ruptured AAA?
SBP of 70-90 mmHg. (FIRST AID says 80-100 mmHg) You can allow some permissive hypotension in order to avoid exacerbating the hemorrhage.
Do this with BLOOD. Try to avoid crystalloids if you can (there is a risk of dilution all coagulopathy and iatrogenic acidosis).
Avoid this part of the ABCs of ressucitation in ruptured AAA if you can’t
Intubation - because induction can lead to cardiovascular collapse
Who can be discharged home with a AAA and who gets admitted?
Home: Asymptomatic incidental findings <5cm with outpatient vascular surgery f/u.
OR symptoms clearly not related to their AAA
Admit: Acutely symptomatic without rupture. Any of the complications such as AE and AV fistulas and microemboli.
Rupture goes straight to the O.R.
What is considered a “rapidly expanding” AAA?
> 1cm increase in size per year
This increases the risk for rupture and should be considered for repair.
Describe the risk of rupture based on the size of a AAA
<4.0cm —> 0% risk of rupture in a year 4-5cm —> 0.5% - 5.0% risk of rupture in a year 5-6cm —> 3-15% 6-7cm —> 10-20% 7-8cm —> 20-40% >8cm —> 30-50%
Estimated prevalence of AAA in patient’s aged 50-85?
1.4%
Percentage of patients that survive a ruptured AAA of those who arrive alive at the hospital?
50-70%
Overall mortality of AAA rupture is 85-90% (a lot die before getting to the hospital)
What are the two types of AAA rupture? How do they differ clinically?
- Into the retroperitoneal space: a “contained rupture”. Creates tamponade effect at rupture site causing blood pressure to stabilize temorarily
- Intraperitoneal space: a “free rupture” leading to rapid exsanguination, shock, and rapid death
What is a patient with a ruptured AAA is HYPERtensive? Should you lower the BP?
This is controversial - Europe says no, North America says yes
- Use Esmolol, nitroglycerin, or sodium nitroprusside. But consult vascular surgery first and let them help decide if this is needed.
What are the main complications of AAA grafting (both endovascular and open)?
- Aortoenteric fistula (presents as GI bleed)
- Graft infection (can present 3 years later or more for open repairs, usually sooner for endovascular repairs)
- Limb occlusion
- Para-anastomotic aneurysm formation
- Endoleak (Only with endovascular repair)
