Aneurysm Flashcards
Define a true aneurysm?
An aneurysm is a 50% increase of the normal diameter of an artery.
The aneurysm usually involves more than one layer of the wall.
They may be fusiform (symmetrical) or saccular (a local swelling).
What are the common sites for aneurysm formation?
Abdominal Aorta
Iliac Artery
Femoral Artery
Popliteal Artery
Outline the pathophysiology of a thoracic aortic dissection?
An aortic dissection starts with an intimal tear.
This tear allows blood to leak into the intima, blood floe through this tear causes the intima to seperate from the adventitia creating a false lumen.
Eventually more blood can flow through the false lumen leading to ischaemia of distal organs.
Describe the clinical presentation of a dissection?
Sharp severe tearing pain in the chest or back. Sudden onset and maximal at its onset. The pain will migrate as the dissection extends.
Typical patient will be a man in his 60’s with hypertension.
Ant. chest pain suggest involvement of the ascending aorta which has a worse prognosis.
What are the complications of an aortic dissection? What is the prognosis?
Complications: Shock, Aortic regurgitation/ insufficiency (occurs in 50%), May involve branches off the aorta: renal = renal impairment coeliac = persistent abdominal pain catotid = hemiparesis
Outcomes: External rupture, double lumen or cardiac tamponade.
Rupture associated with an 80% mortality
40% die in 1st 24hrs
80% die within 2 weeks
Describe the management of aortic dissection?
Analgesia, fluids, ICU, X match
Maintain BP between 100-120 mmHg using IV b blockers (reduces ventricular contraction) +/- vasodilators
Type A:
- Resection of the section and prosthetic graft +/- arch replacement
Type B:
- Medical management
- Thoracic endovascular aortic repair (TEVAR) if severe/ actute
Describe the signs and symptoms of a ruptured AAA? List the other potential differentials?
Unruptured AAA’s are assymptomatic but may have an expansile abdominal mass.
Ruptured AAA’s:
Shock.
Syncope or collapse.
Abdominal, back or loin pain, sudden and severe.
Differentials: Any causes of acute abdominal pain and shock: Cholangitis Pancreatitis Peritonitis Ectopic
Describe the management of AAA rupture?
Have a low index of suspicion over 50 male with abdominal pain, must consider it.
Resuscitation
Major haemorrhage protocol good access, send X match.
Aim for a systolic of 100 as greater than this increases bleeding.
Emergency surgery:
- EVAR (endovascular aneurysm repair)
- Open procedure
Describe the surveillance of AAAs?
- 0-4.4 cm: annual ultrasound.
- 5-5.4 cm: 3-monthly ultrasound.
- 5 cm or bigger - consider surgery (see below), 3-monthly ultrasound.
What is a false aneurysm?
Also known as a pseudoaneurysm.
It is when there is a breach in the vessel wall such that blood leaks through the wall but is contained by the adventitia or surrounding perivascular soft tissue.
At a high risk of rupturing and therefore require treatment.
Describe the presentation of popliteal aneurysms?
Often asymptomatic.
Main risk is that there is embolisation of a thrombus from the aneurysm causing acute limb ischaemia.
Can also rupture however this is less common.
Often they are bilateral and associated with AAA.
Describe the management of popliteal aneurysms?
Treated even if asymptomatic due to risk of embolisation.
Endovascular graft OR bypass surgery.
Name 4 indications for AAA EVAR.
- Rapid expansion over 1cm a year
- Onset of sinister symptoms such as back or abdominal tenderness
- AAA >6cm
- High risk patients e.g. CKD
Name factors that predispose Aneurysm formation
Atherosclerosis, arteriosclerosis, Ehlers Danlos Syndrome, Marfans, Mycotic infection, Syphilis, high blood pressure, Congenital (Berry), Trauma (Angiocatheters)
Name factors predispose Aortic Dissection
High blood pressure, Ehlers Danlos, Marfans
