Aortic aneurysm: sizing, growth and repair thresholds — structured viva

Stem

Practice viva. The examiner asks how you measure and follow a dilated aorta, when you would send a patient for repair at each segment, how heritable disease changes the numbers, and what happens after endovascular repair.^[1]

Branch A — Measuring and following the thoracic aorta

Examiner: A 64-year-old man has a 46 mm ascending aorta on TTE. How do you confirm and follow it?^[1]

Strong answer:

• ESC 2024: in thoracic aortic dilatation, CCT or CMR is recommended to confirm TTE measurements, rule out asymmetry and set baseline diameters for follow-up (Class I, Level C).^[1]
• Measure leading-to-leading edge in end-diastole on echocardiography and inner-to-inner edge in end-diastole on CT or CMR, using double-oblique images (each Class I, Level C).^[1]
• ESC 2024 text (no class or level given): imaging is required at 6–12 months after diagnosis, depending on aetiology and baseline diameter; it can then be performed annually if there is no expansion or extension, or customized to the underlying condition; closer evaluation every 6 months is recommended with rapid expansion (≥3 mm per year) or as the surgery or endovascular repair threshold approaches.^[1]
• Its formal row: follow-up imaging with TTE, CCT or CMR (based on aneurysm location) should be considered annually if there is no expansion or extension, or customized according to baseline aortic diameter and the underlying condition (Class IIa, Level C).^[1]
• ACC/AHA 2022: follow-up imaging in 6 to 12 months is reasonable and, if stable, every 6 to 24 months depending on diameter (COR 2a, LOE C-LD).^[2]

Follow-up: His TTE 12 months later shows 49 mm. Do you believe it?^[1]

• ESC 2024: if TTE shows an increase of ≥3 mm per year, confirmation by CCT or CMR should be considered (Class IIa, Level C).^[1]
• Its text asks for the same technique, centre and method with side-by-side comparison.^[1]

Branch B — Thresholds by segment

Examiner: Give me the elective repair thresholds you would quote for each segment.^[1]

Strong answer:

• Root or ascending aorta with a tricuspid valve: surgery at ≥55 mm (ESC 2024, Class I, Level B); ACC/AHA 2022 says surgery is indicated at ≥5.5 cm when asymptomatic (COR 1, LOE B-NR).^[1][2]
• Isolated asymptomatic arch aneurysm at low operative risk: open replacement should be considered at ≥55 mm (ESC 2024, Class IIa, Level B).^[1]
• Unruptured descending aneurysm without HTAD: elective repair at ≥55 mm (ESC 2024, Class I, Level B), by TEVAR over open repair when anatomy is suitable (Class I, Level B).^[1]
• Unruptured degenerative TAAA: elective repair at ≥60 mm (ESC 2024, Class I, Level B).^[1]
• AAA: elective repair at ≥55 mm in men or ≥50 mm in women (ESC 2024, Class I, Level A).^[1]

Follow-up: Is there an American growth trigger at the root?^[2]

• ACC/AHA 2022: an aneurysm of the root or ascending aorta <5.5 cm whose growth confirmed by tomographic imaging is ≥0.3 cm/y in 2 consecutive years, or ≥0.5 cm in 1 year, is an indication for surgery (COR 1, LOE C-LD).^[2]

Branch C — Heritable disease and bicuspid valves

Examiner: How do Marfan syndrome and a bicuspid valve change your thresholds?^[1]

Strong answer:

• Marfan syndrome: surgery is indicated for aortic root disease with a maximal sinus diameter ≥50 mm (ESC 2024, Class I, Level B) and should be considered at ≥45 mm with additional risk factors (Class IIa, Level C).^[1]
• ESC 2024 lists the Marfan risk factors as a family history of dissection at <50 mm, resistant hypertension and annualized growth ≥3 mm in adults.^[1]
• Bicuspid aortopathy: surgery is recommended at ≥55 mm, and at ≥50 mm for the root phenotype (each ESC 2024, Class I, Level B); for the ascending phenotype at low surgical risk it should be considered at >52 mm (Class IIa, Level B).^[1]
• In Marfan syndrome, a beta-blocker or an ARB in maximally tolerated doses (unless contraindicated) is recommended to reduce the rate of aortic dilatation (ESC 2024, Class I, Level A).^[1]

Branch D — After endovascular repair

Examiner: A patient asks why he needs scans after his EVAR.^[1]

Strong answer:

• ESC 2024 says patients treated by EVAR are more prone to late complications (endoleaks, migration or rupture) and re-interventions, so lifelong surveillance is currently mandatory.^[1]
• Imaging with CCT (or CMR) and duplex or contrast-enhanced ultrasound at 1 and 12 months, then yearly ultrasound with CCT or CMR every 5 years if there are no abnormalities (ESC 2024, Class I, Level A).^[1]
• After EVAR, re-intervention to achieve a seal is recommended for type I endoleak and, principally by endovascular means, for type III endoleak (ESC 2024, each Class I, Level B).^[1]
• In EVAR trial 1 (1252 patients aged ≥60 years with AAA ≥5.5 cm, suitable and fit for either procedure, randomised to EVAR or open repair at 37 UK centres in 1999–2004; mean follow-up 12.7 years), overall mortality was similar (adjusted HR 1.11, 95% CI 0.97–1.27); EVAR had lower mortality at 0–6 months, but beyond 8 years open repair had significantly lower mortality; the increased aneurysm-related mortality with EVAR after 8 years was mainly attributable to secondary aneurysm sac rupture.^[7]