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