Abdominal Aortic Aneurysm (AAA)

Transcription

1 Abdominal Aortic Aneurysm (AAA) Vascular Workshop: Objectives Anatomy Keith VanHaltren Indications Technique Cases Abdominal Aorta: Normal Size Abdominal aortic aneurysm: Definition Normal diameter of the infrarenal aorta cm in men cm in women Aneurysmal dilatation of the aorta weakened walls Risk factors Smoking HT Atherosclerosis / hypercholesterolaemia Advancing age Abdominal aortic aneurysm :Prevalence Abdominal Aortic Aneurysm: Size Primary focus of AAA ultrasound screening is size Risk increases dramatically after 50 >3.0cm diameter of the infrarenal aorta Over 65: 4-7% of men 1-2% of women >50% increase in size Ectasia cm Important to be aware of may progress to AAA Surveillance 1

2 Abdominal Aortic Aneurysm: Risk of Rupture AAA Ultrasound: Clinical Indications Follow-up / Surveillance pre & post intervention Pulsatile mass / abdominal bruit Back pain or flank pain Known risk factors Largely asymptomatic incidental AAA Ultrasound: Surveillance AAA Ultrasound Technique AAA Ultrasound: Setup AAA Ultrasound: Examination Low frequency C5-1 transducer Fast 4-6 hrs Vascular preset Supine position typically Left lateral decubitus if large or significant gas Aorta / AAA Long Trans Measurements* Colour / Spectral Doppler Renal artery origins Both common iliac arteries Both kidneys 2

3 AAA Ultrasound: Measurements Measurement: Caliper placement Caliper placement important Outer to outer Transverse measurements Parallel to long axis of aorta Correlate with previous imaging CT or previous US Make meaningful comparison Measurement: Ensuring correct axis AAA Ultrasound: Images to take AAA Ultrasound: Images to take AAA Ultrasound: Iliacs Associated aneurysmal change > 1.5cm Important for intervention planning Risk of rupture 3

4 Abdominal Aortic Aneurysm: Intervention AAA Ultrasound: Post intervention Open repair EVAR FEVAR Nellix EVAS AAA Intervention: Open Repair AAA Intervention: EVAR Endovascular Aortic Repair Surgical open and repair of aneurysm Fabric covered stents From proximal non aneurysmal aorta to iliacs AAA Intervention: FEVAR AAA Intervention: Nellix EVAS Nellix Endovascular Aneurysm Sealing System Fenestrated Endovascular Aortic Repair New concept in EV repair Two balloon expandable stents surrounded by an endobag For RA / SMA / CA Stents placed in the proximal aorta to iliac arteries Endobag filled with polymer to obliterate aneurysmal lumen and achieve a seal In theory, resist lateral and longitudinal displacement forces Obliterates aneurysmal sac, eliminating endoleaks 4

5 Leakage of blood into a excluded aneurysm sac Common complication of EVAR May progress to rupture Types of endoleaks Cause 1 Incomplete sealing of the proximal or distal end of graft 2 Collaterals - Inferior mesenteric artery - Lumbar artery - Ileo-lumbar artery 3 Stent-graft failure 4 Stent-graft porosity 5 (Endotension) Progressive increase in sac diameter without evidence of endoleak Type 2 is commonest Low scale Endoleak: Contrast US Careful assessment with colour Be very suspicious if increasing aneurysm size post EVAR Contrast enhanced ultrasound Conclusion: What s important Careful measurement of size Max AP and Transverse Diameter Interval change Endoleak State limitations 5