Acute Aortic Dissection: Evidence, Uncertainties, and Future Therapies

Authors, Journal, Affiliations, Type, DOI

• Authors: Bartosz Rylski, Oliver Schilling and Martin Czerny — Department of Cardiovascular Surgery, University Heart Centre Freiburg, and Institute for Surgical Pathology, University of Freiburg
• Journal: European Heart Journal. 2023;44:813–821 (State of the Art Review, "Cardiac and vascular surgery")
• Type: State-of-the-art review, ESC journal
• DOI: https://doi.org/10.1093/eurheartj/ehac757

Overview

Rylski and colleagues reframe dissection therapy around two variables rather than the Stanford letter alone: where the primary entry tear is, and in which directions the dissection propagates. Every effective intervention, open or endovascular, is shown to do the same thing — eliminate the most proximal communication between the two lumens, decompress the true lumen, stabilise the flap, and ideally thrombose the false lumen. This makes the treatment decision anatomical rather than categorical.

The paper's substantive contribution is its argument that non-A non-B dissection deserves to be a category of its own — 7–11% of all dissections, involving the arch but not the ascending aorta, with roughly half the entries in the arch and half in the descending aorta. It also introduces the TEM classification (Type, Entry, Malperfusion) and the GERAADA score for operative risk, and argues for the Endo-Bentall concept as the next frontier in type A.

Keywords

Aortic dissection · type A · type B · non-A non-B · primary entry tear · TEM classification · GERAADA score · frozen elephant trunk · TEVAR · Endo-Bentall · malperfusion · biomarkers · proteomics

Key Takeaways

Classification

• Stanford: type A involves the ascending aorta regardless of arch or descending involvement; non-A non-B involves the arch but not the ascending; type B involves only the descending aorta.
• DeBakey: type 1 ascending and descending, type 2 ascending only, type 3a descending thoracic, 3b descending thoracic and abdominal.
• TEM classification (Sievers et al.) adds the entry location — E0 not visible, E1 ascending, E2 arch, E3 descending — and malperfusion status — M0 none, M1 coronary, M2 supra-aortic, M3 visceral/renal/lower limb — with a + for clinical and − for radiological malperfusion.
• Most TEM type A E1 M0 patients benefit from ascending replacement; most type A E2 M3+ patients need arch replacement with frozen elephant trunk, because a mere ascending replacement does not address a visceral malperfusion caused by true-lumen collapse.

Aortic entry anatomy predicts behaviour

• Entry at the lesser curvature carries a high risk of retrograde propagation to type A, because the supra-aortic vessels at the greater curvature form an anatomical barrier. Non-A non-B E2 dissections are in fact always located at the greater curvature; an entry at the lesser curvature of the arch would have become a type A.
• An entry within 2 cm of the left subclavian artery is an anatomical risk factor for later complications in initially uncomplicated type B.
• A proximal communication >10 mm predicts rapid aortic growth or rupture.

Type A: outcomes and risk

• Operative mortality varies from 5% to 75% according to preoperative condition — neurological injury, malperfusion and extent of disease.
• The GERAADA score predicts 30-day mortality from age, sex, resuscitation, previous cardiac surgery, intubation, catecholamines, aortic regurgitation, malperfusion, neurological status and dissection extent. Neither TEM nor GERAADA is intended as a criterion for withholding treatment.
• Reported 30-day mortality is now in single digits at some centres and has fallen below 8% in a Japanese nationwide series of nearly 12,000 patients.

Non-A non-B

• Two-thirds require aortic repair within 2 weeks of diagnosis; one-third require emergency repair, most often for rupture or malperfusion.
• TEVAR should be avoided in TEM non-A non-B E2 because it cannot occlude an arch entry and carries a retrograde type A risk of up to 26%. Frozen elephant trunk is the effective option, and its stent-graft segment provides a landing zone for later distal TEVAR.
• Because the aorta enlarges to aneurysm in up to 60% of patients after dissection, a staged approach — index FET, then distal TEVAR extension, then a third procedure if needed — has low perioperative risk and good outcomes.

Type B

• INSTEAD and INSTEAD-XL showed TEVAR plus best medical treatment gave false lumen thrombosis in 91% versus 19% with medical treatment alone, with better aortic-related survival at 5 years. ADSORB showed similar early remodelling. This underpins the ESC Class IIa recommendation for TEVAR in uncomplicated type B.
• Repair in the acute phase is usually for malperfusion, retrograde propagation or persistent pain; in the subacute and chronic phases, usually for increasing diameter.
• Risk factors for growth: initial descending diameter >40 mm, false lumen >22 mm, entry at the lesser curvature or near the left subclavian, communication >10 mm.

Acute medical therapy (applies to every type)

• IV beta-blockade to heart rate control and SBP 100–120 mmHg in the acute phase; in chronic dissection, BP below 140/90 mmHg.
• Lifestyle: moderate physical activity, smoking cessation, blood pressure control, healthy diet.

Future directions

• Endo-Bentall — a single-stage endovascular valve-carrying conduit with three landing zones (annulus, sinotubular junction, distal ascending) — is anatomically feasible in about two-thirds of type A patients but has not been tested clinically, and industry interest is limited.
• Biomarkers: aggrecan is higher in dissection than in aneurysm, myocardial infarction or health; soluble ST2 outperformed D-dimer and troponin I as a rule-out marker. Proteomic profiling is promising but none of it is clinically established.

Limitations of the document

• A narrative review with no systematic search or evidence grading; its recommendations carry the authors' authority, not a guideline's.
• Endo-Bentall is presented as an aspiration, and the feasibility figure comes from an anatomical study, not from implanted devices.
• The biomarker section is a literature sampler without a meta-analysis, and the authors concede that no consensus findings have emerged.
• No cost, access or training analysis, despite recommending centralisation of type A dissection care.
• The paper covers only acute dissection, excluding IMH and PAU as separate entities, so it cannot carry the whole acute aortic syndrome.

Key Concepts Mentioned

concepts/Acute-Aortic-Syndrome · concepts/Acute-Aortic-Syndrome · concepts/Thoracic-Aortic-Aneurysm

Key Entities Mentioned

INSTEAD · INSTEAD-XL · ADSORB · GERAADA registry · TEM classification

Wiki Pages Updated

• concepts/Acute-Aortic-Syndrome — updated with TEM classification, non-A non-B, frozen elephant trunk
• concepts/Acute-Aortic-Syndrome — created and cross-linked
• index — hub entry added