5.2. Proposed management of unTBAD patients
TEVAR is the treatment of choice in coTBAD (ESC guidelines: class I, level of evidence C) (46) for patients with appropriate anatomy (46, 56, 57). It is most effective for aortic remodelling unTBAD in the acute and subacute stages (1), and is also recognised as a treatment to prevent future aortic complications in unTBAD (ESC guidelines: class IIA, level of evidence B) (46). Therefore, the most pertinent risk factors for unTBAD progression to coTBAD should inform candidate selection for TEVAR. At present, there are no clear clinical guidelines using risk-stratification to inform the selection of unTBAD patients for TEVAR. A recent systematic review and meta-analysis (58) has also highlighted that reporting of false lumen status, aortic diameters and growth, and demographic data has not always been congruent with the most recent recommendations published by the Society for Vascular Surgery and Society of Thoracic Surgeons (59). Given that these recommendations are adhered to in future, discussion on optimal unTBAD patient selection for TEVAR will become increasingly granular and allow for the formulation of strong evidence-based guidelines.
In the interim, we reason that the risks quantified in Tables 2 & 3 could inform the execution of the treatment algorithm shown inFigure 4 . It is imperative to focus on high-risk imaging features identified in Table 3 (e.g., primary entry tear diameter >10 mm, initial total aortic diameter ≥ 40 mm, false lumen ≥ 22 mm, patent false lumen) which are likely to indicate unstable disease in apparently clinically stable patients (36, 42, 60). If the imaging features are present, demographic, clinical and laboratory parameters (Table 2 ) could then be considered.Figure 4 outlines a pragmatic approach towards TEVAR intervention given its procedural risks and requirement for specialist aortic care; thorough patient imaging could guide the selection of patients at high risk of disease progression for deferred endovascular treatment within the 14 to 90 day subacute phase which appears to be the optimal TEVAR intervention time (1). Moreover, specific subsets of acute unTBAD patients that are at high risk of developing downstream aortic complications may qualify for early prophylactic endovascular therapy.
Table 2. Clinical and laboratory parameters in unTBAD patients that could be used to predict need for intervention. HR: Hazard ratio; OR: Odds Ratio; FDP: Fibrin degradation products.