Ultrasound of Abdominal Aortic Aneurysm (AAA) :-

1 - Shape : Fusiform, saccular or hour-glass (double aneurysms).

2 - Size : Measure the total AP, TR and CC diameters as well as the residual lumen in cases of luminal thrombosis.

3 - Origin : If it arises from supra-renal or infra-renal location and any branches involvement.

4 - Extent : Where it ends, above or at the bifurcation or involving the common, external or internal iliac arteries.

_ Then Look from inside outwards >>

5 - Lumen : Any thrombosis inside, surface of thrombus, liquefied areas within thrombus or intimal flap as in dissecting aneurysm (which appears as floating echogenic membrane like structure), any flow within false lumen,…

6 - Wall : It is smooth, calcified or irregular, ill-defined, if the latter is seen then suspect rupture or leakage.

7 - Outside : Any complex collection, haematoma as in rupture or peri-aortic echogenic fat as in mycotic aneurysm, also LOOK at both Psoas muscles texture and size for any signs of rupture.

Practical points:-

  • Avoid midline compression by transducer pressure, and examine the patient in decubitus position.
    This technique is preferred in any elderly patient esp. those complaining of possible pulsatile abdominal mass.
  • If you see AAA during the scan, try to the check the distal arterial tree, esp. if you see luminal thrombus within AAA.
  • Any elderly patient with loin, lumbar pain, hydronephrosis, peri-nephric collection seen during the scan, … please check for rupture AAA with the resultant haematoma causing ureteric compression