The IRAD and beyond: what have we unravelled so far?

Can Open Distal Repair Be Safely Used in All Patients with Type A Acute Aortic Dissection?

PURPOSE

The distal suture line during aortic dissection repair can be performed by a closed technique or by an open technique. This study presents a retrospective comparison of both methods regarding their postoperative outcomes.

PATIENTS AND METHODS

120 patients who underwent surgery for acute aortic dissection type A were divided into two groups. In group A (n = 81), open distal anastomosis was performed under hypothermic circulatory arrest and selective cerebral perfusion. In group B (n = 39), distal anastomosis was performed with the aorta cross-clamped under mildly hypothermic cardiopulmonary bypass. Primary outcomes were operative mortality, neurologic morbidity, and long-term survival.

RESULTS

Hospital mortality (17.3% for the open group vs. 12.8% for the closed group, p = 0.53), permanent neurologic dysfunction (8.7% vs. 8.3%, p = 1.0), and temporary neurologic dysfunction (31.9% vs. 22.2%, p = 0.298) were not significantly different between groups. No significant difference in actuarial 5- and 10-year survival was observed (88% vs. 86% and 53 vs. 73%, respectively, p = 0.396). After propensity-score adjustment, the technique of distal aortic repair was not found to be a predictor of the primary outcomes.

CONCLUSION

We conclude that the open repair can be used in most if not all cases of surgical repair of type A acute aortic dissection.

Decision making and management of acute type-A dissection presenting with shock or cardiac arrest

While the outcome of aortic repair for acute type-A aortic dissection has improved, overall mortality among patients who developed acute type-A aortic dissection remains extremely high. Hypotension in acute type-A aortic dissection patients is a critical condition that is associated with increased in-hospital mortality and neurologic events. The underlying causes of shock include acute aortic regurgitation, cardiac tamponade, and myocardial infarction. The most reasonable initial approach is to administer intravenous fluids to improve blood pressure, increase preload and cardiac output, and ensure adequate end-organ perfusion. Cardiac tamponade-induced hypotension associated with aortic rupture has been identified as a major risk factor for perioperative mortality in patients with acute type-A aortic dissection. In addition, the most serious complications of acute type-A aortic dissection include preoperative cardiopulmonary arrest, especially out-of-hospital cardiopulmonary arrest. Recent advances in rapid transportation and diagnosis, and the introduction of extracorporeal cardiopulmonary resuscitation, have resulted in an increase in the number of patients with cardiopulmonary arrest related to acute type-A aortic dissection. However, controversy continues to surround treatment strategies, surgical indications, and the timing of surgery on such patients. This review, therefore, discusses decision-making and the managerial issues surrounding acute type-A dissection presenting with shock, cardiac tamponade, and cardiac arrest.

18F-Sodium Fluoride Positron Emission Tomography and Computed Tomography in Acute Aortic Syndrome

BACKGROUND

Acute aortic syndrome is associated with aortic medial degeneration. 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) detects microscopic tissue calcification as a marker of disease activity.

OBJECTIVES

In a proof-of-concept study, this investigation aimed to establish whether 18F-NaF PET combined with computed tomography (CT) angiography could identify aortic medial disease activity in patients with acute aortic syndrome.

METHODS

Patients with aortic dissection or intramural hematomas and control subjects underwent 18F-NaF PET/CT angiography of the aorta. Aortic 18F-NaF uptake was measured at the most diseased segment, and the maximum value was corrected for background blood pool activity (maximum tissue-to-background ratio [TBRmax]). Radiotracer uptake was compared with change in aortic size and major adverse aortic events (aortic rupture, aorta-related death, or aortic repair) over 45 ± 13 months.

RESULTS

Aortic 18F-NaF uptake co-localized with histologically defined regions of microcalcification and elastin disruption. Compared with control subjects, patients with acute aortic syndrome had increased 18F-NaF uptake (TBRmax: 1.36 ± 0.39 [n = 20] vs 2.02 ± 0.42 [n = 47] respectively; P < 0.001) with enhanced uptake at the site of intimal disruption (+27.5%; P < 0.001). 18F-NaF uptake in the false lumen was associated with aortic growth (+7.1 mm/year; P = 0.011), and uptake in the outer aortic wall was associated with major adverse aortic events (HR: 8.5 [95% CI: 1.4-50.4]; P = 0.019).

CONCLUSIONS

In patients with acute aortic syndrome, 18F-NaF uptake was enhanced at sites of disease activity and was associated with aortic growth and clinical events. 18F-NaF PET/CT holds promise as a noninvasive marker of disease severity and future risk in patients with acute aortic syndrome. (18F Sodium Fluoride PET/CT in Acute Aortic Syndrome [FAASt]; NCT03647566).

[Acute Aortic Dissection: A Life-Threatening Disease Also in Neurological Emergency Medicine]

Acute aortic dissection is rare but life-threatening. The symptoms depend on the localization and reduced perfusion of the downstream organs or limbs and are therefore variable. Neurological symptoms may occur that do not immediately lead to a diagnosis and thus delay the necessary therapy. Knowing the early symptoms and warning signs of aortic dissection is therefore also crucial in neurological emergency care for quickly identifying the affected patients and for providing acute therapy. A misdiagnosis with delayed initiation of therapy can significantly worsen the patient's outcome. This study aims to establish a standardized diagnostic and therapeutic algorithm for suspected acute aortic dissection in neurological emergency care. Close interdisciplinary cooperation is mandatory.

Imaging and Surveillance of Chronic Aortic Dissection: A Scientific Statement From the American Heart Association

All patients surviving an acute aortic dissection require continued lifelong surveillance of their diseased aorta. Late complications, driven predominantly by chronic false lumen degeneration and aneurysm formation, often require surgical, endovascular, or hybrid interventions to treat or prevent aortic rupture. Imaging plays a central role in the medical decision-making of patients with chronic aortic dissection. Accurate aortic diameter measurements and rigorous, systematic documentation of diameter changes over time with different imaging equipment and modalities pose a range of practical challenges in these complex patients. Currently, no guidelines or recommendations for imaging surveillance in patients with chronic aortic dissection exist. In this document, we present state-of-the-art imaging and measurement techniques for patients with chronic aortic dissection and clarify the need for standardized measurements and reporting for lifelong surveillance. We also examine the emerging role of imaging and computer simulations to predict aortic false lumen degeneration, remodeling, and biomechanical failure from morphological and hemodynamic features. These insights may improve risk stratification, individualize contemporary treatment options, and potentially aid in the conception of novel treatment strategies in the future.

Acute aortic syndromes: a review of what we know and future considerations

Acute aortic syndromes represent a spectrum of life-threatening aortic pathologies. Prompt diagnosis and proper management of these syndromes are important in reducing overall mortality and morbidity, which remains high. Acute aortic dissections represent most of these aortic wall pathologies, but intramural haematomas and penetrating atherosclerotic ulcers have been increasingly diagnosed. Type A dissections require prompt surgical treatment, with endovascular options on the horizon. Type B dissections can be complicated or uncomplicated, and treatment is determined based on this designation. Complicated Type B dissections require prompt repair with thoracic endovascular aortic repair (TEVAR) becoming the preferred method. Uncomplicated Type B dissections require medical management, but early TEVAR in the subacute setting is becoming more prominent. Proper surveillance for an uncomplicated Type B dissection is crucial in detecting aortic degeneration and need for intervention. Intramural haematomas and penetrating atherosclerotic ulcers are managed similarly to aortic dissections, but more research is needed to determine the proper management algorithms. Multi-disciplinary aortic programmes have been shown to improve patient outcomes and are necessary in optimizing long-term follow-up.

Self-Radiopaque Markers Guiding Physician-Modified Fenestration (S-Fenestration) in Aortic Arch Endovascular Repair

Backgrounds and Objectives: Thoracic endovascular aortic repair (TEVAR) has currently become the “first-line choice” for descending aortic pathologies. For pathologies located at the aortic arch, TEVAR with physician-modified fenestration (PMF) has been gained popularity as an alternative choice. However, stent fenestration is an experience-dependent technique and comes with possible adverse events such as misalignment. This study aims to introduce the self-radiopaque PMF (SF), which uses the radiopaque marker as a guiding indicator.

Methods: This is a single-center retrospective study of 125 patients who underwent the SF-TEVAR in Second Xiangya Hospital from December 2015 to December 2020. Data include basic clinical information and technique records of SF-TEVAR with follow-up results.

Results: According to the SF-TEVAR protocol, we have performed the procedures on 125 patients and obtained an instant success rate of 98.4%. A total of 140 aortic stent-grafts and 44 bridging stents have been implanted in this study. The operation time is 64.6 ± 19.3 min, X-ray exposure time (from first digital subtraction angiography (DSA) to last DSA) is 25.6 ± 14.3 min, and contrast volume is 82.2 ± 22.6 ml. The success rate of PMF alignment is 98.4%. One bailout stent-graft was implanted into the left subclavian artery (LSA) by the chimney technique (0.8%). One fenestration was successfully and immediately corrected after misalignment (0.8%). Large simultaneous fenestration was performed in six patients (4.8%) for the left common carotid artery (LCCA) and LSA and in two patients (1.6%) for IA, LCCA, and LSA. One hundred twenty-two out of 125 patients' LSAs have been kept patent by the technique during the follow-up. The bridging stent group consists of 44 patients who received LSA stents, while the non-bridging stent group includes the other 81 patients. Type I endoleak has occurred in seven patients (5.6%) 1 week after the procedure. During follow-up (23 ± 18 months), survival rate is 95.7% and branch artery patent rate is 97.4%.

Conclusions: The SF-TEVAR technique, which utilizes the radiopaque marker in stent-graft as an indication for PMF in TEVAR, seems a likely safe, effective, and efficient procedure that brings acceptable survival rate and branch artery patency rate. SF-TEVAR serves as a progressive alternative method to keep the branch artery patent in aortic arch endovascular reconstruction.

Midterm outcomes of fenestrated TEVAR using physician-modified endovascular grafts for zone 2

OBJECTIVES

To summarize the experience and midterm outcomes of physician-modified endovascular grafts for zone 2 thoracic endovascular aortic repair.

METHODS

A retrospective analysis was conducted of 51 consecutive patients (mean age 57.6 ± 12.5 years, 39 males) treated with thoracic endovascular aortic repair using physician-modified endovascular grafts for reconstructing the left subclavian artery from November 2015 to December 2019. The primary endpoints during follow-up were the overall mortality, aorta-related mortality, and major complications. The secondary endpoints were reintervention and the patency of the target branches, the demographics and technical details were also described and analyzed.

RESULTS

Sixty-three thoracic stent-grafts were deployed in 51 patients and emergency surgery was performed in 10 patients (19.6%). Technical success was 94.1% (48/51). The incidence of perioperative complications was 15.7%, and the 30-day mortality was 0%. At a mean follow-up of 42.0 ± 14.4 months (range, 14-63 months), all the left subclavian arteries remained patent. All-cause mortality was 3.9% (2/51) and not aorta-related deaths. Estimated survival at one and three years was 98.0 ± 1.9% and 96.0 ± 2.8%, respectively.

CONCLUSIONS

The physician-modified endovascular grafts is feasible and effective to preserve left subclavian artery in thoracic endovascular aortic repair for aortic arch pathologies with unhealthy proximal landing zone.

OPG/TRAIL ratio as a predictive biomarker of mortality in patients with type A acute aortic dissection

Following hospital discharge, patients with type A acute aortic dissection (TA-AAD) may present an increase in mortality risk. However, little is known about specific biomarkers associated with post-discharge survival, and there is a paucity of prognostic markers associated with TA-AAD. Here, we identify nine candidate proteins specific for patietns with TA-AAD in a cross-sectional dataset by unbiased protein screening and in-depth bioinformatic analyses. In addition, we explore their association with short-term and long-term mortality in a derivation cohort of patients with TA-AAD, including an internal (n = 300) and external (n = 236) dataset. An elevated osteoprotegerin (OPG)/tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) ratio was the strongest predictor of overall, 30-day, post-30-day mortality in both datasets and was confirmed to be a strong predictor of mortality in an independent validation cohort (n = 400). Based on OPG/TRAIL ratio-guided risk stratification, patients at high risk (>33) had a higher 1-year mortality (55.6% vs. 4.3%; 68.2% vs. 2.6%) than patients at low risk (<4) in both cohorts. In Conclusion, we show that an elevated OPG/TRAIL ratio is associated with a significant increase in short-term and long-term mortality in patients with TA-AAD.

Clinical profiles and outcomes of acute type A aortic dissection and intramural hematoma in the current era: lessons from the first registry of aortic dissection in China

BACKGROUND

Acute type A aortic dissection (ATAAD) and acute type A intramural hematoma (ATAIMH) are life-threatening diseases with high mortality. To better understand their clinical features in the Chinese population, we analyzed the data from the first Registry of Aortic Dissection in China (Sino-RAD) to promote the understanding and management of the diseases.

METHODS

All patients with ATAAD and ATAIMH enrolled in Sino-RAD from January 1, 2012 to December 31, 2016 were involved. The data of patients' selection, history, symptoms, management, outcomes, and postoperation complications were analyzed in the study. The continuous variables were compared using the Student's t test for normal distributions and the Mann-Whitney U test for non-normal distributions. Categorical variables were compared using the Chi-square test or Fisher exact test.

RESULTS

A total of 1582 patients with ATAAD and 130 patients with ATAIMH were included. The mean age of all patients was 48.4 years. Patients with ATAAD were significantly younger than patients with ATAIMH (48.9 years vs. 55.6 years, P < 0.001). For the total cohort, males were dominant, but the male ratio of patients with ATAAD was significantly higher compared to those with ATAIMH (P = 0.01). The time range from the onset of symptom to hospitalization was 2.0 days. More patients of ATAIMH had hypertension than that of ATAAD (82.3% vs. 67.6%, P < 0.05). Chest and back pain were the most common clinical symptoms. Computerized tomography (CT) was the most common initial diagnostic imaging modality. 84.7% received surgical treatment and in-hospital mortality was 5.3%. Patients with ATAAD mainly received surgical treatment (89.6%), while most patients with ATAIMH received medical treatment (39.2%) or endovascular repair (35.4%).

CONCLUSIONS

Our study suggests that doctors should comprehensively use clinical examination and genetic background screening for patients with ATAAD and ATAIMH and further shorten the time range from symptoms onset to intervention, achieving early diagnosis and treatment, thereby reducing the mortality rate of patients with aortic dissection in China. We should standardize the procedures of aortic dissection treatment and improve people's understanding. Meanwhile, the curing and transferring efficiency should also be improved.

Ultrasound diagnosis of dissecting thoracic aortic aneurysms: procedure with a handheld device and a video-illustrated case

Acute thoracic aortic dissection is an uncommon, although not rare, life-threatening condition. With protean signs and symptoms that often suggest more common cardiac or pulmonary conditions, it can be difficult to diagnose. Ultrasound has proven useful in making the correct diagnosis. This case demonstrates that training gained using standard ultrasound machines can be easily and successfully adapted to newer handheld ultrasound devices. The examination technique using the handheld device is illustrated with photos and a video.

Impact of time between diagnosis to treatment in Acute Type A Aortic Dissection

There is a paucity of data describing the effect of time interval between diagnosis and surgery for Acute Type A Aortic Dissection. We describe our 8-year experience and investigate the impact of time interval between symptom onset, diagnosis and surgery on outcomes. Retrospective single-center study utilizing our Society of Thoracic Surgeons registry and patient records. Subjects were grouped by time interval between radiographic diagnosis and surgical treatment: Group A (0-4 h), Group B (4.1-8 h), Group C (8.1-12 h), and Group D (12.1 + h). Data were analyzed to identify factors associated with mortality and outcomes. 164 patients were included. Overall mortality was 21.3%. Group C had the greatest intervals between symptom onset to diagnosis to surgery, and also the highest mortality (66.7%). Preoperative tamponade, cardiac arrest, malperfusion, elevated creatinine, cardiopulmonary bypass time, and blood transfusions were associated with increased mortality, while distance of referring hospital was not. Time intervals between symptom onset, diagnosis and surgery have a significant effect on mortality. Surgery performed 8-12 h after diagnosis carries the highest mortality, which may be exacerbated by longer interval since symptom onset. Time-dependent effects should be considered when determining optimal strategy especially if inter-facility transfer is necessary.

Differential clinical features and long-term prognosis of acute aortic syndrome according to disease entity

AIMS

To evaluate the acute and long-term prognosis of acute aortic syndrome (AAS) according to the disease entity [intramural haematoma (IMH) vs. aortic dissection (AD)] and the anatomical location (type A vs. B).

METHODS AND RESULTS

A total of 1012 patients [672 with AD and 340 with IMH (33.6%)] were enrolled between 1993 and 2015. Compared with AD patients, IMH patients were older and had higher frequency of female sex and distal aorta involvement. The overall crude in-hospital mortality of AAS was 8.6%; type A AD [15.0%; adjusted hazard ratio (aHR) 30.4; 95% confidence interval (CI) 8.62-107.3; P < 0.001], type A IMH (8.0%; aHR 4.85; 95% CI 1.29-18.2; P = 0.019), type B AD (5.0%; aHR 3.51; 95% CI 1.00-12.4; P = 0.051), and type B IMH [1.5%; aHR 1.00 (reference)]. During a median follow-up duration of 8.5 years (interquartile range: 4.0-13.5 years), AD (aHR 2.78; 95% CI 1.87-4.14; P < 0.001) and type A (aHR 2.28; 95% CI 1.45-3.58; P < 0.001) was associated with a higher risk of aortic death. After 90 days, a risk of aortic death was no longer associated with anatomical location (aHR 0.74; 95% CI 0.40-1.36; P = 0.33), but remained associated with disease entity (aHR 1.83; 95% CI 1.10-3.04; P = 0.02).

CONCLUSION

The clinical features, response to treatment strategy, and outcomes of IMH patients were distinct from those of AD patients. Both early and late survival was better for IMH than for AD. In addition to the anatomical location of AAS, the disease entity is an independent factor associated with both acute and long-term mortality in patients with AAS. Further investigation is necessary to confirm the prognostic implication of disease entity in different patient populations.

Finite element modeling to predict procedural success of thoracic endovascular aortic repair in type A aortic dissection

Objective

Thoracic endovascular aortic repair (TEVAR) is recommended for type B aortic dissection and recently has even been used in selected cases of proximal (Stanford type A) aortic dissections in scenarios of prohibitive surgical risk. However, mechanical interactions between the native aorta and stent-graft are poorly understood, as some cases ended in failure. The aim of this study is to explore and better understand biomechanical changes after TEVAR and predict the result via virtual stenting.

Methods

A case of type A aortic dissection was considered inoperable and selected for TEVAR. The procedure failed due to stent-graft migration even with precise deployment. A novel patient-specific virtual stent-graft deployment model based on finite element method was employed to analyze TEVAR-induced changes under such conditions. Two landing positions were simulated to investigate the reason for stent-graft migration immediately after TEVAR and explore options for optimization.

Results

Simulation of the actual procedure revealed that the proximal bare metal stent pushed the lamella into the false lumen and led to further stent-graft migration during the launch phase. An alternative landing position has reduced the local deformation of the dissection lamella and avoided stent-graft migration. Higher maximum principal stress (>20 KPa) was found on the lamella with deployment at the actual position, while the alternative strategy would have reduced the stress to <5 KPa.

Conclusions

Virtual stent-graft deployment simulation based on finite element model could be helpful to both predict outcomes of TEVAR and better plan future endovascular procedures.

Painless type A aortic dissection

Aortic dissection is an uncommon diagnosis that typically presents with acute onset of severe pain. It rarely presents with minimal to no symptoms, which carries a higher mortality risk given the delay in diagnosis. An adequate interpretation of risk factors, clinical findings and auxiliary tests constitutes a greater value for clinicians to detect this life-threatening condition. This report describes a case of type A aortic dissection in an asymptomatic patient presenting with an abnormal electrocardiogram (ECG).

Familial Aortopathies - State of the Art Review

Aortopathies are conditions that result in aortic dilatation, aneurysm formation and dissection. Familial aortopathies (perhaps better known as heritable thoracic aortic aneurysm and dissection, h-TAAD, as not all have a positive family history) are recognised to have an underlying genetic cause and affect the aorta, predisposing it to the above pathologies. These conditions can also affect the extra-aortic vasculature, particularly large elastic arteries and other body systems. Mutations in a number of genes have been associated with h-TAAD. However, not all affected families have a pathogenic gene variant identified-highlighting the importance of a three-generational family history and the likely role of both environmental factors and future gene discoveries in furthering knowledge. Survival has improved over the last few decades, essentially due to surgical intervention. The benefit of identifying affected individuals depends upon a regular surveillance program and timely referral for surgery before complications such as dissection. Further research is required to appreciate fully the effects of individual gene variants and improve evidence for prophylactic medical therapy, as well as to understand the effect of h-TAAD on quality of life and life choices, particularly around exercise and pregnancy, for affected individuals. This will be complemented by laboratory-based research that seeks to understand the tissue pathways that underlie development of arterial pathology, ideally providing targets for novel medical therapies and a means of non-invasively identifying individuals at increased vascular risk to reduce dissection, which remains a devastating life-threatening event.

Contrast-Induced Kidney Nephropathy in Thoracic Endovascular Aortic Repair: A 2-Year Retrospective Study in 470 Patients

We identified changes in renal function in patients who underwent thoracic endovascular aortic repair (TEVAR) and the factors that may influence renal function. Information on 470 consecutive patients was collected. Kidney function and contrast volume were recorded. Unpaired t test, Spearman correlation, and logistic regression were used for statistical analysis. A Kaplan-Meier curve helped clarify our follow-up findings. Mean contrast volume was 90.5 ± 21.2 mL. The change in serum creatinine was significantly correlated with (1) preexisting renal pathology (P = .033) and (2) aortic dissection (AD) involving the renal arteries (P = .019). The change in serum urea nitrogen (ΔBUN) was only significantly correlated with AD involving the renal arteries (P = .0348). Contrast volume (P = .036, odds ratio = 1.010, 95% confidence interval: 1.001-1.019) was a risk factor for contrast-induced nephropathy (CIN) after TEVAR. Survival rates and renal failure rates among no CIN, CIN, and CIN-acute kidney injury groups at longest 27 months follow-up were significantly different. Creatinine and BUN were generally elevated post-TEVAR. Contrast-induced nephropathy post-TEVAR may correlate with renal comorbidities and renal artery involvement. Contrast volume is risk factor for CIN after TEVAR. More attention needs to be paid to patient renal function during follow-up.

Early experience and technical aspects of physician-modified fenestration in thoracic endovascular aortic repair for aortic arch pathologies

Objective

This study was performed to describe the treatment of aortic arch pathologies with a physician-modified fenestration (PMF) technique in thoracic endovascular aortic repair (TEVAR).

Methods

From August 2015 to August 2017, 32 patients with aortic arch pathologies underwent TEVAR with the PMF technique. All patients’ clinical data were analyzed with GraphPad Prism 7.0.

Results

Thirty-four aortic stent-grafts were implanted in 32 patients. The mean proximal diameter of the stent-graft was 32.4 ± 3.4 cm, and the mean length was 170.0 ± 25.2 cm. Twenty-nine PMF procedures were performed to preserve the left subclavian artery (LSA) and three to preserve both the LSA and left common carotid artery. The mean distance between the pathology and LSA was 8.4 ± 4.0 mm. The mean procedure time (from first to last digital subtraction angiography) was 22.8 ± 20.8 min. The mean follow-up time was 8.3 ± 5.3 months. During follow-up, the all-cause survival rate was 83.3% and the patency rate of the branch artery after PMF was 96.0%.

Conclusion

The PMF technique is a relatively safe, feasible, and time-saving method to preserve the branch artery in TEVAR for aortic arch pathologies. The short- to middle-term result of this technique is satisfactory.

Detection of Type B Aortic Dissection in the Emergency Department with Point-of-Care Ultrasound

Aortic dissection (AD) is a rare, time-sensitive, and potentially fatal condition that can present with subtle signs requiring timely diagnosis and intervention. Although definitive diagnosis is most accurately made through computed tomography angiography, this can be a time-consuming study and the patient may be unstable, thus preventing the study’s completion. Chest radiography (CXR) signs of AD are classically taught yet have poor diagnostic reliability. Point-of-care ultrasound (POCUS) is increasingly used by emergency physicians for the rapid diagnosis of emergent conditions, with multiple case reports illustrating the sonographic signs of AD. We present a case of Stanford type B AD diagnosed by POCUS in the emergency department in a patient with vague symptoms, normal CXR, and without aorta dilation. A subsequent review of CXR versus sonographic signs of AD is described.

Aortic arch tortuosity, a novel biomarker for thoracic aortic disease, is increased in adults with bicuspid aortic valve

INTRODUCTION

Arterial tortuosity has emerged as a predictor of adverse outcomes in congenital aortopathies using 3D reconstructed images. We validated a new method to estimate aortic arch tortuosity on 2D CT. We hypothesize that arch tortuosity may identify bicuspid aortic valve (BAV) patients at high risk to develop thoracic aortic aneurysms or aortic dissections (TAD).

METHODS

BAV subjects with chest CT scans were retrospectively identified in our clinical records and matched to tricuspid aortic valve (TAV) controls by age, gender, and presentation with TAD. Subjects with prior ascending aortic intervention were excluded. Measurements included aortic arch tortuosity, length, angle, width and height. Total aortic tortuosity was estimated in subjects with available abdominal images.

RESULTS

120 BAV and 234 TAV subjects were included. Our 2D measurements were highly correlated with 3D midline arch measurements and had high inter- and intra-observer reliability. Compared to TAV, BAV subjects had increased arch tortuosity (median 1.76 [Q1-Q3: 1.62-1.95] vs. 1.63 [1.53-1.78], P < 0.01), length (149 [136-160] vs. 135 [122-152] mm, P < 0.01), height (46 [41-53] vs. 39 [34-47] mm, P < 0.01), and vertex acuity (70 [61-77] vs. 75 [68-81] degree, P < 0.01). In a multivariable analysis, arch tortuosity remained independently associated with BAV after adjusting for aortic diameter and other clinical characteristics.

CONCLUSIONS

We found that aortic arch tortuosity is significantly increased in BAV and may identify BAV patients who are at increased risk for TAD. Further studies to evaluate the association between tortuosity and clinical outcomes are in progress.

False lumen intervention to promote remodelling and thrombosis-The FLIRT concept in aortic dissection

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has changed the management of aortic dissection by induced remodelling. Beyond reconstructing the true lumen, we describe the concept of False Lumen Intervention to promote Remodelling and Thrombosis (FLIRT) in both type A and B aortic dissection.

METHODS

Between 2011 and 2017, 10 patients with aortic dissection (5 type A; 5 type B) underwent FLIRT using a combination of patent foramen ovale (PFO) or atrial septal defect (ASD) occluders, coils and glue. Patients were followed by computed tomography (CT) angiogram prior to, and 6 months following, discharge to evaluate false lumen (FL) thrombosis and aortic remodelling. Outcomes analyzed comprised successful device delivery, completeness of FL thrombosis and aortic remodelling, procedure related complications and mortality.

RESULTS

FLIRT induced aortic remodelling in all cases of proximal dissection, with aortic shrinkage from 63.8 ± 7.5 pre-FLIRT, to 50.2 ± 6.6 mm (P = 0.057) and an increase in true lumen area from 5.8 ± 3.6 to 11.4 ± 2.5 cm2 (P = 0.006). In distal dissection (after previous TEVAR with residual FL flow), FLIRT successfully induced FL thrombosis in 4 of 5 cases at first attempt (1 case required additional coiling of the gutter between left subclavian artery and stent-graft for complete thrombosis). While maximal aortic diameter remained unchanged (55.6 ± 9.1 pre-FLIRT and 54.4 ± 13.7 mm at follow-up), true lumen area increased from 7.8 ± 2.3 pre-procedure, to 10.6 ± 1.5 cm2 at follow-up (P = 0.016), consistent with remodelling.

CONCLUSION

Interventional FL management, using the FLIRT concept, is feasible in selected cases of aortic dissection, promotes FL thrombosis and induces successful remodelling.

Distinguishing acute from chronic aortic dissections using CT imaging features

The aim was to compare computed tomography (CT) features in acute and chronic aortic dissections (AADs and CADs) and determine if a certain combination of imaging features was reliably predictive of the acute versus chronic nature of disease in individual patients. Consecutive patients with aortic dissection and a chest CT scan were identified, and 120 CT scans corresponding to 105 patients were reviewed for a variety of imaging features. Statistical tests assessed for differences in the frequency of these features. A predictive model was created and tested on an additional 120 CT scans from 115 patients. Statistically significant features of AAD included periaortic confluent soft tissue opacity, curved dissection flap, and highly mobile dissection flap, and features of CAD included thick dissection flap, false lumen (FL) outer wall calcification, FL thrombus, dilated FL, and tear edges curling into the FL. The model predicted the chronicity of a dissection with an area under the curve of 0.98 (CI 0.98-1.00). AADs and CADs demonstrated significantly different CT imaging features.