Aortic Aneurysm

theDoc

July 5, 2022
2 min read

An aortic aneurysm is an abnormal dilatation of the aortic lumen. The infrarenal aorta is the most common site. The descending thoracic aorta may be involved, while ascending aortic aneurysms are rare.

Risk factors and etiology;

Male sex
Age>60 years
Smoking
Dyslipidemia
Arterial hypertension
Atherosclerosis
Trauma
Bicuspid aortic valve for thoracic aortic aneurysm ( TAA)
Tertiary syphilis
Connective tissue disease, e.g., Marfan’s syndrome
Genetic factors- tends to run in families

Clinical features

Dependent on the site

TAA – acute severe chest pain

Others – stridor, superior vena cava syndrome, thoracic back pain
Massive bleeding if it erodes into the esophagus or bronchi

Abdominal aortic aneurysm (AAA) – pain in the central abdomen, lower back, loin, iliac fossa, or groin

Signs of compression to the duodenum or inferior vena cava
Examination- pulsatile abdominal mass, bruit on auscultation

The usual age of presentation is 75 to 85 years for emergency presentations and 65 to 75 years for elective presentation

Investigations

1. Ultrasound is the best way to establish a diagnosis and follow-up for those patients with a small aneurysm not warranting surgery

In the UK, screening for men >65 has been started.

2. CT scan- more accurate in size and extent of the aneurysm, surrounding structures, and presence of other pathology. It is suitable for pre-operative investigation

Management

Until an asymptomatic AAA reaches 5.5cm in diameter, the risks of surgery outweigh the benefits

Indications for surgery;

Ruptured AAA
Pain- it predates rupture
Distal embolization
Diameter ≥5.5 cm for AAA and descending TAA, and ≥6.5cm for ascending TAA
An expansion rate of >1cm per year
Symptomatic aneurysm

Surgical procedures;

1. Open aortic aneurysm repair has been the treatment of choice. The aneurysmal segment is replaced with a prosthetic graft. Patients who survive the procedure have a long-term survival approaching that of the general population

It is also indicated for mycotic aneurysms and infected grafts, and when EVAR fails

2. Endovascular aneurysm repair(EVAR)- is increasingly replacing open surgery. A stent is introduced via the femoral arteries. It is cost-effective and likely to become the treatment of choice. It is also preferred in patients not suitable for open surgery

-Beta-blockers if the aneurysm is due to Marfan’s syndrome- to reduce the rate of aortic dilatation and risk of rupture

-Elective replacement of the ascending aorta in those with evidence of progressive aortic dilatation. It, however, carries a mortality rate of 5 to 10%

Complications of aortic aneurysms