Abdominal Aortic Aneurysm Acute Aortic Syndromes American Association for Surgery of Trauma Aortic Dissection Acute Type B Aortic Dissection Coeliac Artery Coronary Artery Disease Common Carotid Artery Chronic Obstructive Pulmonary Disease Cerebrospinal Fluid Computed Tomography Computed Tomographic Angiography Chronic Type B Aortic Dissection Digital Subtraction Angiography Descending Thoracic Aorta Descending Thoracic Aortic Aneurysm Electrocardiogram Ehlers-Danlos Syndrome European Journal of Vascular and Endovascular Surgery Erythrocyte Sedimentation Rate European Society for Vascular Surgery False Lumen Giant Cells Arteritis Intramural Haematoma International Registry of Aortic Dissection Intravascular Ultrasonography Loeys-Dietz Syndrome Left Heart Bypass Left Subclavian Artery Mean Arterial Pressure Motor Evoked Potentials Marfan Syndrome Magnetic Resonance Angiography Magnetic Resonance Imaging Nephrogenic Systemic Fibrosis Open Repair Penetrating Aortic Ulcer Positron Emission Tomography Polymyalgia Rheumatica Randomized Clinical Trial Spinal Cord Ischaemia Superior Mesenteric Artery Somatosensory Evoked Potentials Takayasu Arteritis Thoraco-Abdominal Aortic Aneurysm Thoracic Aortic Injury Type B Aortic Dissection Thoracic Endovascular Repair True Lumen Transoesophageal Echocardiography Turner Syndrome Transthoracic Echocardiography Writing Committee The European Society for Vascular Surgery (ESVS) appointed the Descending Thoracic Aorta (DTA) Writing Committee (WC) to produce the current clinical practice guidelines document for surgeons and other physicians who are involved in the overall care of patients with DTA disorders. The goal of these guidelines is to summarize and evaluate all current available evidence to assist physicians in selecting the best management strategies for all DTA pathologies. However, each respective physician must make the ultimate decision regarding the particular care of an individual patient. The present guidelines document aims to improve decision making and decrease variability in the vascular surgical care of patients presenting with pathology of the DTA. Unfortunately, robust evidence from prospective and randomized studies is not available for management of most DTA diseases. Consequently, the recommendations in these guidelines are entirely based on level B and C evidence. Nevertheless, when managing DTA pathology, it is clinically helpful to have access to the most recent and best available clinical and experimental knowledge to determine the current standard of care. The DTA WC intentionally agreed to exclude pathology of the ascending aorta and aortic arch from the current document to avoid potential inter-specialty conflict. The cost analysis of different treatments was also excluded because of differences in financial management and differing health systems across Europe. Primarily infectious or mycotic disease processes were also considered outside of the scope of this document because of their low incidence and poor outcomes. All disorders originating in the DTA from the left subclavian artery (LSA) origin to the diaphragm were considered for these guidelines. Pathology involving the thoraco-abdominal segment of the aorta was also included. The DTA WC was formed by members of the ESVS from different European countries, various academic and private hospitals, and by both vascular surgeons and endovascular specialists, to maximize the applicability of the final guidelines document. The DTA Guidelines Committee met in November 2011 for the first time to discuss the purpose, contents, methods, and timeline of the following recommendations. The DTA WC performed a systematic English literature search in the MEDLINE, EMBASE, and COCHRANE Library databases for each of the different topics that are discussed and reviewed. The latest literature search was performed in December 2015. With regard to evidence gathered, the following eligibility criteria were applied:•Only peer reviewed published literature was considered•Published abstracts or congress proceedings were excluded•Randomized clinical trials (RCT) as well as meta-analyses and systematic reviews were assessed with priority•Non-randomized clinical trials and non-controlled studies were included•Well conducted observational studies (cohort and case control studies) were included•Previous guidelines, position papers, and published consensus documents were included as part of the review process when new evidence was absent•We minimized the use of reports from a single medical device or from pharmaceutical companies in order to reduce the risk of bias across studies. A grading system was adopted based on the European Society of Cardiology (ESC) guidelines methodology.1European Society of Cardiology. Recommendations for guidelines production. www.escardio.org/static_file/Escardio/Guidelines/about/ESC_Guidelines_for_Guidelines_Update_2012_for_web.pdf.Google Scholar The level of evidence classification provides information about the study characteristics supporting the recommendation and expert consensus, according to the categories shown in Table 1.Table 1Levels of evidence.1European Society of Cardiology. Recommendations for guidelines production. www.escardio.org/static_file/Escardio/Guidelines/about/ESC_Guidelines_for_Guidelines_Update_2012_for_web.pdf.Google Scholar The recommendation grade indicates the strength of a recommendation. Definitions of the classes of recommendation are shown in Table 2.Table 2Grades of strength of recommendations according to the ESC grading system.1European Society of Cardiology. Recommendations for guidelines production. www.escardio.org/static_file/Escardio/Guidelines/about/ESC_Guidelines_for_Guidelines_Update_2012_for_web.pdf.Google Scholar For each recommendation, two members of the WC assessed the strength of a recommendation and the quality of supporting evidence independently. A full master copy of the manuscript with all recommendations was electronically circulated and approved by all WC members. Recommendations that required consensus were discussed and voted on by email among all members of the WC. This system permits strong recommendations, supported by low or very low quality evidence from downgraded RCTs or observational studies, only when a general consensus is achieved among the WC members and reviewers. Two members of the WC prepared each part of the guidelines document. An internal review process was performed before the manuscript was sent to independent external reviewers. External reviewers made critical suggestions, comments, and corrections on all preliminary versions of this guideline. In addition, each member participated in the consensus process concerning conflicting recommendations. The final document was reviewed and approved by the ESVS Guidelines Committee and submitted to the European Journal of Vascular and Endovascular Surgery (EJVES). Further updated guidelines documents on DTA management will be provided periodically by the ESVS when new evidence and/or new clinical practice arise in this field. To optimize the implementation of the current document, the length of the guideline has been kept as short as possible to facilitate access to guideline information. Following this decision, the “References” list has been limited to the most relevant references related to these guidelines. Nevertheless, an Appendix of recommended additional references, also reviewed by the WC, has been added for further information for readers. This clinical guidelines document was constructed as a guide, not a document of rules, allowing for flexibility with various patient presentations. The resulting clinical practice guidelines provide recommendations for the clinical care of patients with thoracic aortic diseases including pre-, peri-, and post-operative care. Conflicts of interest of each WC member were collected prior to the writing process. These conflicts were assessed and accepted by each member of the WC and are reported on the ESVS website. In addition, the WC agreed that all intellectual work should be expressed without any interference beyond the honesty and professionalism of all members and assistants during the writing process. The DTA originates from the isthmus, the region of the thoracic aorta between the origin of the LSA and the ductus arteriosus. The descending thoracic aorta runs in a left para-spinal location until its distal segment, where it passes anteriorly through the diaphragmatic aortic hiatus and inferiorly into the abdomen. Important aortic side branches originating from the descending thoracic aorta include the intercostal arteries, spinal arteries, and bronchial arteries. The normal diameter of the mid-descending aorta ranges from 24 to 29 mm in men and 24 to 26 mm in women, whereas the normal diameter at the level of the diaphragm is 24 to 27 mm in men and 23 to 24 mm in women. Aortic diameter is influenced by age and body mass index.2Johnston K.W. Rutherford R.B. Tilson M.D. Shah D.M. Hollier L. Stanley J.C. Suggested standards for reporting on arterial aneurysms. Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery.J Vasc Surg. 1991; 13: 452-458Abstract Full Text Full Text PDF PubMed Scopus (684) Google Scholar, 3Kälsch H. Lehmann N. Möhlenkamp S. Becker A. Moebus S. Schmermund A. et al.Body-surface adjusted aortic reference diameters for improved identification of patients with thoracic aortic aneurysms: results from the population-based Heinz Nixdorf Recall study.Int J Cardiol. 2013; 163: 72-78Abstract Full Text Full Text PDF PubMed Scopus (29) Google Scholar The aortic wall is composed of three layers: the intima, media, and adventitia. The intima, the innermost layer, consists of an endothelial monolayer and an internal elastic lamina. Because it is in direct contact with blood, the function of the intima is to prevent thrombosis and atherosclerosis. Its anti-thrombotic and anti-atheroscle-rotic function can be reduced by risk factors, such as smoking, hypertension, hyperlipidaemia, diabetes, and direct trauma, each making patients more prone to aortic disease. The media consists of concentric layers of elastin, collagen, and smooth muscle cells. These components are responsible for aortic wall elasticity, which accommodates the changes in stroke volume during the cardiac cycle, converts pulsatile inflow into a smoother outflow (Windkessel function), and maintains the integrity of the aortic wall. Congenital or hereditary disorders (e.g. bicuspid aortic valve, Marfan syndrome [MFS], Ehlers-Danlos syndrome [EDS]), risk factors (hypertension, atherosclerosis, and trauma) all influence aortic wall function. These conditions can stiffen the aortic wall, decreasing its ability to accommodate the stroke volume, resulting in systemic hypertension, or weakening of the aortic wall, leading to dilatation or dissection. The adventitia is the outermost layer of the aortic wall and is composed mainly of collagen fibres, external elastic lamina, and small vessels (the vasa vasorum), which provide the blood supply to the aortic wall and surrounding nerves. DTA diseases consist of a broad spectrum of degenerative, structural, acquired, genetic, and traumatic disorders. The true incidence of descending thoracic aortic pathology remains unclear. Epidemiological studies are sparse and it is likely that many DTA related deaths are attributed to other cardiovascular diseases, such as cardiac arrest, myocardial infarction, cerebrovascular accidents, or abdominal aneurysm rupture. Therefore, the overall incidence of DTA disease is likely to be underestimated. The pathophysiology of thoracic aortic diseases is believed to be multifactorial, resulting both from genetic susceptibility and environmental exposure. Therefore, the incidence of the different thoracic aortic diseases can vary significantly among different population groups. Acute aortic syndromes (AAS) consist of three interrelated diseases: aortic dissection, penetrating aortic ulcer (PAU), and intramural haematoma (IMH). Type B aortic dissection (TBAD) most commonly affects male patients and has an incidence between 2.9 and 4.0 per 100,000 person-years.4Clouse W.D. Hallet Jr., J.W. Shaff H.V. Spittell P.C. Rowland C.M. Ilstrup C.M. et al.Acute aortic dissection: population-based incidence compared with degenerative aortic aneurysm rupture.Mayo Clin Proc. 2004; 79: 176-180Abstract Full Text Full Text PDF PubMed Google Scholar The incidence of TBAD seems to be increasing. A recent prospective analysis of 30,412 middle aged men and women from Malmö, Sweden with a 20 year follow up reported an incidence of acute aortic dissection of 15 per 100,000 patient years.5Landenhed M. Engstrom G. Gottsater A. Caulfield M.P. Hedblad B. Newton-Cheh C. et al.Risk profiles for aortic dissection and ruptured or surgically treated aneurysms: a prospective cohort study.J Am Heart Assoc. 2015; 4: e001513Crossref PubMed Google Scholar This increase is probably caused by the increasing age of the population and improving diagnostic modalities. The exact incidence remains unknown, but PAU has been diagnosed with increasing frequency because of the widespread use of advanced cross sectional imaging techniques. In symptomatic patients suspected of AAS, the prevalence of PAU is 2.3–7.6% and the lesion is localised in the DTA in 90% of patients.6Eggebrecht H. Nienaber C.A. Neuhauser M. Baumgart D. Kische S. Schmermund A. et al.Endovascular stent graft placement in aortic dissection: a meta-analysis.Eur Heart J. 2006; 27: 489-498Crossref PubMed Scopus (0) Google Scholar IMH may be related to PAU, accounting for 5–20% of patients with AAS and more commonly involving the DTA (60%) than the ascending aorta.7Evangelista A. Mukherjee D. Mehta R.H. O'Gara P.T. Fattori R. Cooper J.V. et al.Acute intramural hematoma of the aorta: a mystery in evolution.Circulation. 2005; 111: 1063-1070Crossref PubMed Scopus (277) Google Scholar Trauma is the leading cause of death during the first four decades of life, accounting for more than 250,000 deaths every year in the European Union alone.8http://ec.europa.eu/eurostat/statistics-explained/index.php/Transport_accident_statistics#Main_statistical_findings.Google Scholar Blunt aortic injury is the second leading cause of death in these patients, and although it occurs in less than 1% of all motor vehicle accidents, it accounts for 16% of all traumatic deaths.9European Commission. Mobility and transport. Road safety. http://ec.europa.eu/transport/road_safety/specialist/statistics/.Google Scholar Concerning ruptured descending thoracic aortic aneurysm (DTAA), a Swedish population study reported an incidence of 5 per 100,000 person-years. The mean age of patients in this cohort was 70 years for men and 72 years for women.10Johansson G. Markström U. Swedenborg J. Ruptured thoracic aortic aneurysms: a study of incidence and mortality rates.J Vasc Surg. 1995; 21: 985-988Abstract Full Text Full Text PDF PubMed Scopus (198) Google Scholar Aneurysmal dilatation of the DTA is a degenerative disease with an estimated incidence of 6–10.4 per 100,000 person-years. The incidence seems to be increasing with ageing of the general population and continually improving diagnostic modalities.11Fowkes F.G. Macintyre C.C. Ruckley C.V. Increasing incidence of aortic aneurysms in England and Wales.BMJ. 1989; 298: 33-35Crossref PubMed Google Scholar Aortitis is a relatively uncommon disorder with a broad spectrum of clinical features. The most common autoimmune disorders affecting the DTA are Takayasu's arteritis (TA), giant cell arteritis (GCA), and Behçet's disease. The best estimates of the incidence of TA suggest that two or three cases occur each year per million people.12Karageorgaki Z.T. Bertsias G.K. Mavragani C.P. Kritikos H.D. Spyropoulou-Vlachou M. Drosos A.A. et al.Takayasu arteritis: epidemiological, clinical, and immunogenetic features in Greece.Clin Exp Rheumatol. 2009; 27: S33-S39PubMed Google Scholar There is a 9:1 female to male predominance. Although the disease has a worldwide distribution, it appears to occur more frequently in Asian women. GCA is the most common type of vasculitis observed in patients older than 50 years. Predominantly observed in populations of Scandinavian descent, it has a reported prevalence that varies between 1 and 30 per 100,000 people.13Nordborg E. Nordborg C. Giant cell arteritis: epidemiological clues to its pathogenesis and an update on its treatment.Rheumatology. 2003; 42: 413-421Crossref PubMed Scopus (0) Google Scholar The male to female ratio is around 2.5 to 1 and is highly dependent on geographic and genetic parameters.14Lee J.L. Naguwa S.M. Cheema G.S. Gershwin M.E. The geo-epidemiology of temporal (giant cell) arteritis.Clin Rev Allergy Immunol. 2008; 35: 88-95Crossref PubMed Scopus (38) Google Scholar Behçet's disease has been observed most commonly along the classic Silk Route, with a peak prevalence in Turkey of 80–370 per 100,000 people, compared with 1–3 per million people in the Western world. Presentation is typically in the third to fifth decade of life, and both genders are affected equally.15Idil A. Gurler A. Boyvat A. Caliskan D. Ozdemir O. Isik A. et al.The prevalence of Behcet's disease above the age of 10 years. The results of a pilot study conducted at the Park Primary Health Care Center in Ankara, Turkey.Ophthalmic Epidemiol. 2002; 9: 325-331Crossref PubMed Scopus (0) Google Scholar Coarctation of the aorta is a congenital cardiovascular defect, most commonly occurring at the level of the isthmus and accounts for 5–8% of all congenital heart defects. The overall incidence ranges between 20 and 60 per 100,000 person-years, with a slight male predominance. Patients with Turner syndrome (TS) are more commonly affected.16Teo L.L. Cannell T. Babu-Narayan S.V. Hughes M. Mohiaddin R.H. Prevalence of associated cardiovascular abnormalities in 500 patients with aortic coarctation referred for cardiovascular magnetic resonance imaging to a tertiary center.Pediatr Cardiol. 2011; 32: 1120-1127Crossref PubMed Scopus (24) Google Scholar A comprehensive medical and family history, assessment of symptoms, and careful physical examination including blood pressure measurement and electrocardiography (ECG), are required in all patients suspected of thoracic aortic disease. Patients should be examined for suspicious clinical signs such as aortic regurgitation, cardiac murmur, pericardial rub, signs of tamponade, and an expansile abdominal aorta. The diagnosis of thoracic aortic disease is based on imaging and the choice of imaging modality should be based on the patient's condition and the availability of different imaging modalities.17Goldstein S.A. Evangelista A. Abbara S. Arai A. Asch F.M. Badano L.P. et al.Multimodality imaging of diseases of the thoracic aorta in adults: from the American Society of Echocardiography and the European Association of Cardiovascular Imaging.J Am Soc Echocardiogr. 2015; 28: 119-182Abstract Full Text Full Text PDF PubMed Google Scholar Postero-anterior and lateral chest radiographs can be used to diagnose calcification within atheromatous lesions, left pleural effusions, aortic enlargement, and anomalous aortic contours in asymptomatic or symptomatic patients. A left pleural effusion can indicate a frank rupture, an exudate from inflammation of the adventitia in AAS, or, less commonly, inflammatory aortic disease. The International Registry of Acute Aortic Dissection (IRAD) showed that 21% of patients with a type B aortic dissection presented with a normal chest X-ray, and a meta-analysis demonstrated a sensitivity for an abnormal chest X-ray of 90% for TBAD.18Klompas M. Does this patient have an acute thoracic aortic dissection?.J Am Med Assoc. 2002; 287: 2262-2272Crossref PubMed Google Scholar Although chest X-rays might be used in very low risk patients to exclude thoracic aortic diseases, these potentially lethal diseases require a conclusive diagnosis with the use of multiplanar imaging techniques such as computed tomographic angiography (CTA). The use of TTE to assess the DTA is limited by structures in the thorax that weaken or distort the ultrasound signal and compromise image quality. Via a suprasternal, subcostal, or parasternal view, small parts of the DTA can be visualized, while in the case of a pleural effusion, the back of the patient can be used for transthoracic imaging.19Evangelista A. Flachskampf F.A. Erbel R. Antonini-Canterin F. Vlachopoulos C. Rocchi G. et al.Echocardiography in aortic diseases: EAE recommendations for clinical practice.Eur J Echocardiogr. 2010; 11: 645-658Crossref PubMed Scopus (159) Google Scholar The major advantage of TTE is that it is non-invasive and can be used to visualize the ascending aorta, aortic arch, and supra-aortic vessels. In addition, the abdominal aorta can be visualized to check for abdominal extension of aortic dissection (AD). During TTE, all planes should be used to assess the extent of aortic disease and to exclude additional aortic or cardiac involvement. Because of its non-invasive nature and wide availability, TTE is increasingly used in the emergency department of community hospitals to screen patients suspected of having one or other acute aortic syndrome, such as type A dissection. However, the value of TTE in the diagnosis of DTA pathology remains limited. In cases of examination limitations or inconclusive diagnosis, the use of additional imaging modalities is recommended.19Evangelista A. Flachskampf F.A. Erbel R. Antonini-Canterin F. Vlachopoulos C. Rocchi G. et al.Echocardiography in aortic diseases: EAE recommendations for clinical practice.Eur J Echocardiogr. 2010; 11: 645-658Crossref PubMed Scopus (159) Google Scholar There are currently no specific studies to validate the usefulness of TTE for diagnosis of DTA pathology. TOE can visualize the DTA from the LSA to the coeliac artery (CA). This diagnostic test is generally used as a second line imaging modality and is useful to differentiate between AD, IMH, and PAU. With a reported sensitivity of 98% and a specificity of 95%, TOE is an accurate diagnostic tool for aortic disease, providing functional information in both the pre- and intra-operative settings.19Evangelista A. Flachskampf F.A. Erbel R. Antonini-Canterin F. Vlachopoulos C. Rocchi G. et al.Echocardiography in aortic diseases: EAE recommendations for clinical practice.Eur J Echocardiogr. 2010; 11: 645-658Crossref PubMed Scopus (159) Google Scholar The semi-invasive nature of TOE has rare procedure related risks, but it can cause patient discomfort, requires sedation, and is contraindicated in the presence of oesophageal pathologies. In the majority of cases, computed tomographic angiography (CTA) scanning is performed as the first imaging modality, providing all required information. TOE may be used in specific circumstances as a second line option. CTA offers a detailed visualisation of the entire aorta and its surrounding structures. It can distinguish different aortic pathologies and is quick and widely available. Over the last two decades, CTA has become more sophisticated and is more readily available, with an increase in the number of scanners, the use of retrospective and prospective ECG-gated techniques, and through advances in post-processing software. These advances have resulted in motion free images with better resolution, reduced scanning times, and better visualisation.20Parodi J. Berguer R. Carrascosa P. Khanafer K. Capunay C. Wizauer E. Sources of error in the measurement of aortic diameter in computed tomography scans.J Vasc Surg. 2014; 59: 74-79Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar Current CTA scanners have a sensitivity of up to 100% and a specificity of 98–99%, with slight variations between different DTA pathologies.21Wicky S. Wintermark M. Schnyder P. Capasso P. Denys A. Imaging of blunt chest trauma.Eur Radiol. 2000; 10: 1524-1538Crossref PubMed Scopus (0) Google Scholar Imaging should include a non-contrast study, followed by an early and late phase contrast study and should examine the part of the body between the thoracic inlet and the common femoral arteries. This range provides complete information with three dimensional reconstruction. In addition, dynamic images can further assist in surgical planning or endovascular interventions. Consequently, CTA has replaced digital subtraction aortography as the “gold standard” for aortic imaging. Important disadvantages of CTA include the use of nephrotoxic contrast agents and the exposure of patients to ionizing radiation. In patients at increased risk of contrast induced nephropathy, circulating volume expansion with either isotonic sodium chloride or sodium bicarbonate solutions is recommended.22Ad-hoc Working Group of ERBP Fliser D. Laville M. Covic A. Fouque D. Vanholder R. Juillard L. et al.A European Renal Best Practice (ERBP) position statement on the Kidney Disease Improving Global Outcomes (KDIGO) clinical practice guidelines on acute kidney injury: part 1: definitions, conservative management and contrast-induced nephropathy.Nephrol Dial Transplant. 2012; 27: 4263-4272Crossref PubMed Scopus (188) Google Scholar MRI has an excellent diagnostic capability that is comparable with CTA and TOE and can be used for both pre-operative planning and follow up.23François C.J. Markl M. Schiebler M.L. Niespodzany E. Landgraf B.R. Schlensak C. Four-dimensional, flow-sensitive magnetic resonance imaging of blood flow patterns in thoracic aortic dissections.J Thorac Cardiovasc Surg. 2013; 145: 1359-1366Abstract Full Text Full Text PDF PubMed Google Scholar A major advantage of MRI is that it offers multiplanar evaluation with good differentiation between different soft tissues. Moreover, MRI can provide additional dynamic imaging regarding entry tear flow or arterial vessel involvement.23François C.J. Markl M. Schiebler M.L. Niespodzany E. Landgraf B.R. Schlensak C. Four-dimensional, flow-sensitive magnetic resonance imaging of blood flow patterns in thoracic aortic dissections.J Thorac Cardiovasc Surg. 2013; 145: 1359-1366Abstract Full Text Full Text PDF PubMed Google Scholar Although contrast is not usually required, the use of gadolinium enhances the quality of MRI. MRI can be used to visualize the aortic wall in detail and is, therefore, more commonly used in patients with aortic wall pathologies such as IMH or aortitis. Furthermore, MRI does not require ionizing radiation and offers an alternative for patients with renal insufficiency in some circumstances. Important disadvantages of MRI include its limited availability and longer scanning times, which makes it less suitable for critically ill or unstable patients. In addition, the ability of MRI to detect calcification is decreased (compared with CTA), and artefacts from respiration or metallic implants reduce image quality. Post-gadolinium nephrogenic systemic fibrosis (NSF) is a rare, but devastating, side-effect in patients with impaired renal function. Using alternative imaging modalities or using the lowest possible amount of gadolinium may prevent NSF.24Wang Y. Alkasab T.K. Narin O. Nazarian R.M. Kaewlai R. Kay J. et al.Incidence of nephrogenic systemic fibrosis after adoption of restrictive gadolinium-based contrast agent guidelines.Radiology. 2011; 260: 105-111Crossref PubMed Scopus (87) Google Scholar PET is a nuclear imaging modality that is based on the detection of increased metabolic activity in inflammatory cells, resulting in increased uptake of a gammagraphic tracer, most commonly fluorodeoxyglucose ([18F] FDG). PET can be used for the diagnosis of aortitis and in the assessment of the extent and activity of any inflammatory disease. The diagnostic value of FDG-PET differs among the various inflammatory aortic diseases with a reported sensitivity ranging between 83% and 100% and specificity between 77% and 100%.25Walter M.A. Melzer R.A. Schindler C. Muller-Brand J. Tyndall A. Nitzsche E.U. The value of [18F]FDG-PET in the diagnosis of large-vessel vasculitis and the assessment of activity and extent of disease.Eur J Nucl Med Mol Imaging. 2005; 32: 674-681Crossref PubMed Scopus (229) Google Scholar Development of PET in combination with computed tomography (CT) scanners has made it possible to combine functional and anatomic imaging, thereby making it possible for PET findings to be correlated with adjacent anatomical features. Although the availability of PET and PET/CT is limited, this modality may be used for diagnosis and follow up of aortitis.26Litmanovich D.E. Yıldırım A. Bankier A.A. Insights into imaging of aortitis.Insights Imaging. 2012; 3: 545-560Crossref PubMed Scopus (21) Google Scholar Increased patient radiation exposure is a major disadvantage of PET/CT (when compared with PET or CT examinations alone), as the effective radiation dose is a combination of the dose from both scans.27Huang B. Law M.W. Khong P.L. Whole-body PET/CT scanning: estimation of radiation dose and cancer risk.Radiology. 2009; 251: 166-174Crossref PubMed Scopus (200) Google Scholar IVUS permits 360° visualisation of the aortic wall. It can be very helpful in confirming intimal defects when CTA and digital subtraction angiography (DSA) are inconclusive in the diagnosis of aortic injuries. IVUS is an operator and experience-dependent invasive procedure, and a complete evaluation of the aorta using IVUS can be time consuming. In some centres, IVUS is routinely used as an adjuvant imaging technique during endovascular repair (see also Section 3.1.4.1). Table 3 compares different imaging diagnostic tests for DTA according to their features and performance.Table 3Comparison of different imaging modalities for DTA diagnosis.17Goldstein S.A. Evangelista A. Abba