Your next patient in general practice is a 65 year old Mr. James Skinner who had a health check for travel insurance purposes by one of your colleagues a few days ago when the suspicion of an intra-abdominal pulsating mass was raised and an ultra-sound yesterday confirmed a AAA of 5.5 cm in the classical location below the renal arteries to just above the bifurcation. YOUR TASK IS TO:• Repeat a focused history• Repeat the physical examination• Explain the U/S finding and its significance to the patient• Answer patient’s questions Discussion:
HOPC: Mr. James Skinner is a recently retired accountant who saw another GP in this clinic for a travel insurance health check a few days ago for a 2 months cruise ship holiday around the world. Your colleague felt a suspicious pulsating mass in the centre of the lower abdomen and organised an U/S which revealed a 5.5 cm wide AAA in classical location below the renal artery down to just above the bifurcation.
PHx. + FHx.: unremarkable
SHx: married, retired accountant, 3 adult children, no problems, NKA, no medication, non smoker, little alcohol.
EXAMINATION: well looking man in no distress, normal vital signs.
There is a palpable, pulsatile mass in the lower mid abdomen, no other pathological findings.
DIAGNOSIS: Abdominal aortic aneurysm (AAA)
An aneurysm is a balloon like localised dilatation (outpouching) of an artery with at least 50% increase over normal diameter. It is considered to be due to a degenerative process but the exact cause of the AAA is not known but can be due to several reasons, often multifactorial:
• Atherosclerosis (abnormal thickening and hardening of the arteries, SMOKING!!!, hypertension, diabetes, high cholesterol)
• Idiopathic (the exact cause is not known)
• Familial association (25%)
• Age > 70 years
• Male:female ratio 2:1
• Genetic disorders like Marfan’s or Ehler’s Danlos syndrome
• Other causes include infection, cystic medial necrosis, arteritis, trauma and anastomotic disruption.
Most presentations are asymptomatic with a pulsatile abdominal mass. The aortic bifurcation is located just above the umbilicus.
A pending rupture or a leaking AAA presents with abdominal discomfort or pain, often radiating into the back, with a pulsatile abdominal mass.
However, the symptoms may be vague, and the abdominal mass may be missed. Symptoms may include groin pain, syncope, paralysis, or flank mass. The diagnosis may be confused with renal calculus, diverticulitis, incarcerated hernia, or lumbar spine disease.
Rupture of an aneurysm is a real emergency with 100% mortality if not treated immediately and even with surgery it has a high mortality of about 50-75%!
INVESTIGATIONS:
• Ultrasonography: used as a preliminary screening method to determine aneurysm presence, size, and extent and also as modality for monitoring patients whose aneurysms are too small for surgical intervention, although it is not very accurate in measuring the AAA diameter!
• CT scanning (non enhanced or CT angiography): helps more clearly define the anatomy and morphology of the aneurysm.
• AXR might show calcification in the wall of the aneurysm
• MRI provides the best anatomical definition and 3 dimensional outline.
MANAGEMENT:
1. Immediate referral to a vascular surgeon!
2. Warning the patient to see immediate medical help if abdominal or back pains occur!!!
3. Monitor patients with AAAs smaller than 4 cm in diameter with ultrasound every 6 months, and offer surgical intervention if the aneurysm expands or causes symptoms.
4. Patients with AAAs >5 cm in diamet have a risk of about 10% for rupture within 1 year, over 7 cm the risk is 75% !!!
Therefore these patients benefit from repair, especially if they have other contributing factors for rupture, including hypertension, continued smoking, or chronic obstructive pulmonary disease (COPD).
5. Thorough pre-surgical work-up of the patient!!!
6. The surgery can be either
a) Endoluminal repair by inserting an aortic graft through the common femoral
artery via a catheter with less operative complications and a lower elective
operative mortality of only 1.2%!
b) open abdominal approach involving the clamping of the aorta, an placement of
a prosthetic arterial graft (Dacron or Teflon tube); contraindicated in severe
COAD or cardio-vascular disease, in active infection or if patient has a very
high operative risk like advanced CA ! The elective operative mortality is about
4.6% in comparison to almost 75% when operated on for a ruptured AAA!
Pre-operative work-up:
• FBE, U+E’s, LFT’s
• coagulation profile
• Blood group and X-match
• Urinalysis
• ABG’s
• ECG
• CXR
• Lung function test
COMPLICATIONS:
• The usual operative risks like infection, respiratory problems (anaesthetic) etc.
• Blood loss
• Distal embolisation
• DVT
• Intra-abdominal complications like bowel injury and colitis, renal dysfunction, paraplegia etc.
• Impotence (30%)
• Endo leaks with continuous bleeding into the aneurysm
amc clinical exam 
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