Early and late management of type B aortic dissection

Predicting Aneurysmal Degeneration in Uncomplicated Residual Type B Aortic Dissection

The formation of an aneurysm in the false lumen (FL) is a long-term complication in a significant percentage of type B aortic dissection (AD) patients. The ability to predict which patients are likely to progress to aneurysm formation is key to justifying the risks of interventional therapy. The investigation of patient-specific hemodynamics has the potential to enable a patient-tailored approach to improve prognosis by guiding disease management for type B dissection. CFD-derived hemodynamic descriptors and geometric features were used to retrospectively assess individual aortas for a population of residual type B AD patients and analyze correlations with known outcomes (i.e., rapid aortic growth, death). The results highlight great variability in flow patterns and hemodynamic descriptors. A rapid aortic expansion was found to be associated with a larger FL. Time-averaged wall shear stress at the tear region emerged as a possible indicator of the dynamics of flow exchange between lumens and its effect on the evolution of individual aortas. High FL flow rate and tortuosity were associated with adverse outcomes suggesting a role as indicators of risk. AD induces complex changes in vessel geometry and hemodynamics. The reported findings emphasize the need for a patient-tailored approach when evaluating uncomplicated type B AD patients and show the potential of CFD-derived hemodynamics to complement anatomical assessment and help disease management.

Optimal Timing of Pre-emptive Thoracic Endovascular Aortic Repair in Uncomplicated Type B Aortic Dissection: A Network Meta-Analysis

BACKGROUND

This network meta-analysis compares outcomes of optimal medical therapy (OMT) and pre-emptive thoracic endovascular aortic repair (TEVAR) for uncomplicated type B aortic dissection at different phases of chronicity.

METHODS

MEDLINE and EMBASE were searched through November 2023. Pooled short-term outcomes (short-term mortality, perioperative complications) and long-term outcomes (all-cause mortality, aortic-related mortality, aortic re-intervention rates) were calculated.

RESULTS

Systematic review identified 17 studies (2 randomized controlled trials, 3 propensity score matching, and 2 inverse probability weighting). Subacute-phase intervention had lower short-term mortality than the acute-phase (hazard ratio [HR] [95% confidence interval [CI]]=0.60 [0.38-0.94], p=0.027). No significant differences were observed in aortic rupture and paraplegia. Acute-phase TEVAR had a higher stroke incidence than subacute-phase intervention (HR [95% CI]=2.63 [1.36-5.09], p=0.042), chronic (HR [95% CI]=2.5 [1.03-6.2], p=0.043), and OMT (HR [95% CI]=1.57 [1.12-2.18], p=0.008). Acute-phase TEVAR had higher long-term all-cause mortality than subacute-phase intervention (HR [95% CI]=1.34 [1.03-1.74], p=0.03). Optimal medical therapy had elevated long-term all-cause mortality compared with subacute-phase TEVAR (HR [95% CI]=1.67 [1.25-2.33], p<0.001) and increased long-term aortic-related mortality vs acute-phase (HR [95% CI]=2.08 [1.31-3.31], p=0.002) and subacute-phase (HR [95% CI]=2.6 [1.62-4.18], p<0.01) interventions. No significant differences were observed in aortic re-intervention rates.

CONCLUSIONS

Pre-emptive TEVAR may offer lower all-cause mortality and aortic-related mortality than OMT. Considering lower short-term mortality, perioperative stroke rate, and long-term mortality, our findings support pre-emptive TEVAR during the subacute phase.

CLINICAL IMPACT

The optimal timing of pre-emptive thoracic endovascular aortic repair (TEVAR) for uncomplicated type B aortic dissection remains uncertain. This network meta-analysis suggests that the subacute phase (14-90 days from symptom onset) emerges as the optimal timing for pre-emptive TEVAR. This window is associated with lower rates of short-term complications and higher long-term survival rates compared with alternative strategies.

A Systematic Review and an Updated Meta-Analysis of Fenestrated/Branched Endovascular Aortic Repair of Chronic Post-Dissection Thoracoabdominal Aortic Aneurysms

The objective of this study is to present the current outcomes of fenestrated/branched endovascular repair (F/BEVAR) for post-dissection thoracoabdominal aortic aneurysms (PDTAAAs). A systematic review of the literature according to PRISMA guidelines up to October 2023 was conducted (protocol CRD42023473403). Studies were included if ≥10 patients were reported and at least one of the major outcomes was stated. A total of 10 studies with 585 patients overall were included. The pooled estimate for technical success was 94.3% (95% CI 91.4% to 96.2%). Permanent paraplegia developed with a pooled rate of 2.5% (95% CI 1.5% to 4.3%), whereas a cerebrovascular event developed with a pooled rate of 1.6% (95% CI 0.8% to 3.0%). An acute renal function impairment requiring new-onset dialysis occurred with a pooled rate of 2.0% (95% CI 1.0% to 3.8%). Postoperative respiratory failure was observed with a pooled estimate of 5.5% (95% CI 3.8% to 8.1%). The pooled estimate for 12-month overall survival was 90% (95% CI 85% to 93.5%), and the pooled estimates for 24-month and 36-month survival were 87.8% (95% CI 80.9% to 92.5%) and 85.5% (95% CI 76.5% to 91.5%), respectively. Freedom from reintervention was estimated at 83.9% (95% CI 75.9% to 89.6%) for 12 months, 82.8% (95% CI 68.7% to 91.4%) for 24 months and 76.1% (95% CI 60.6% to 86.8%) for 36 months. According to the present findings, F/BEVAR can be performed in PD-TAAAs with high rates of technical success and good mid-term results.

Silent Type-B Aortic Dissection Accidentally Discovered in a COVID-19-Positive Patient

Aortic dissection is a critical medical condition that poses a significant threat to life, and if left untreated, it can lead to high mortality and morbidity rates. The risk of various cardiovascular complications, including aortic dissection, is increased in individuals with coronavirus disease 2019 (COVID-19). However, the significance of aortic dissection as a complication in COVID-19 patients is often underestimated. Traditionally, aortic dissection without pain was considered uncommon. However, recent information indicates that symptoms in patients with aortic dissection can be more diverse than previously believed. The classic symptoms of tearing chest, back, or abdominal pain may be absent, making diagnosis challenging. We present the incidental detection of an asymptomatic Stanford type-B aortic dissection during a computed tomography (CT) scan conducted to evaluate COVID-19. The patient was managed through conservative treatment.

Editor's Choice - Optimal Timing of Thoracic Endovascular Aortic Repair for Uncomplicated Type B Aortic Dissection: A Systematic Review and Meta-Analysis

OBJECTIVE

Type B aortic dissections (TBAD) have a high mortality rate and are challenging to both classify and manage. There is significant evidence supporting the use of early intervention in complicated TBAD with thoracic endovascular aortic repair (TEVAR). Currently, there is equipoise regarding the optimal timing for TEVAR in TBAD. This systematic review answers whether early TEVAR in the hyperacute or acute phase of the disease has improved aorta related events in the one year follow up period with no change in mortality rate when compared with TEVAR in the subacute or chronic phase.

DATA SOURCES

A systematic review and meta-analysis was performed with Preferred Reporting Items for Systematic Reviews and Meta-Analyses literature search guidelines for MEDLINE, Embase, and Cochrane Reviews until 12 April 2021. Inclusion and exclusion criteria targeting the review objective and high quality research were employed by separate authors.

REVIEW METHODS

These studies were then reviewed for suitability, risk of bias, and heterogeneity using the ROBINS-I tool. Results were extracted for the meta-analysis with RevMan using odds ratios with 95% confidence intervals with I2 used to assess heterogeneity.

RESULTS

Twenty articles were included. A meta-analysis showed no significant difference between acute phase TEVAR (excluding the hyperacute phase) and subacute or chronic phase TEVAR for the all cause 30 day and one year mortality rates. Aorta related events in the 30 day post-operative period were unaffected by the timing of intervention but had significant improvement in aorta related events in the one year follow up favouring TEVAR in the acute phase compared with subacute or chronic phase. Risk of confounding was high but with low heterogeneity.

CONCLUSION

Without prospective randomised controlled studies, it is evident that there is improved aortic remodelling in long term follow up with intervention in the acute setting from three to 14 days after symptom onset. This suggests that TEVAR in the acute period of TBAD is both safe and beneficial, and can be considered for early stent grafting based on clinical, anatomical and patient factors.

Advanced risk prediction for aortic dissection patients using imaging-based computational flow analysis

Patients with either a repaired or medically managed aortic dissection have varying degrees of risk of developing late complications. High-risk patients would benefit from earlier intervention to improve their long-term survival. Currently serial imaging is used for risk stratification, which is not always reliable. On the other hand, understanding aortic haemodynamics within a dissection is essential to fully evaluate the disease and predict how it may progress. In recent decades, computational fluid dynamics (CFD) has been extensively applied to simulate complex haemodynamics within aortic diseases, and more recently, four-dimensional (4D)-flow magnetic resonance imaging (MRI) techniques have been developed for in vivo haemodynamic measurement. This paper presents a comprehensive review on the application of image-based CFD simulations and 4D-flow MRI analysis for risk prediction in aortic dissection. The key steps involved in patient-specific CFD analyses are demonstrated. Finally, we propose a workflow incorporating computational modelling for personalised assessment to aid in risk stratification and treatment decision-making.

Thoracic endovascular repair of chronic type B aortic dissection: a systematic review

BACKGROUND

At present, the optimal management strategy for chronic type B aortic dissection (CTBAD) remains unknown, as equipoise remains regarding medical management versus endovascular treatment versus open surgery. However, the results over recent years of thoracic endovascular aortic repair (TEVAR) in CTBAD appear promising. The aim of this systematic review was to provide a comprehensive analysis of the available data reporting outcomes and survival rates for TEVAR in CTBAD.

METHODS

Electronic searches of six databases were performed from inception to April 2021. All studies reporting outcomes, specifically 30-day mortality rates, for endovascular repair of CTBAD were identified. Relevant data were extracted, and a random-effects meta-analysis of proportions or means was performed to aggregate the data. Survival data were pooled using data derived from original Kaplan-Meier curves, which allows reconstruction of individual patient data.

RESULTS

Forty-eight studies with 2,641 patients were identified. Early (<30 days) all-cause and aortic-related mortality rates were low at 1.6% and 0.5%, respectively. Incidence of retrograde type A dissection in the post-operative period was only 1.4%. There were also low rates of cerebrovascular accidents and spinal cord injury (1.1% and 0.9%, respectively). Late follow-up all-cause mortality was 8.0%, however, late aortic-related mortality was only 2.4%. Reintervention rates were 10.1% for endovascular and 6.7% for surgical reintervention. Pooled rates of overall survival at 1-, 3-, 5- and 10-year were 91.5%, 84.7%, 77.7% and 56.3%, respectively.

CONCLUSIONS

The significant heterogeneity in the available evidence and absence of consensus reporting standards are important considerations and concern when interpreting the data. Evaluation of the evidence suggests that TEVAR for CTBAD is a safe procedure with low rates of complications. However, the optimal treatment strategy for CTBAD remains debatable and requires further research. Evidence from high-quality registries and clinical trials are required to address these challenges.

A two-fluid blood stasis model for false lumen thrombosis after type B dissection repair

The formation of thrombosis is a major concern in the false lumen (FL) for post-TEVAR (thoracic endovascular aortic repair) patients. Blood stasis is one of the key factors which lead to the formation of thrombosis in the arterial systems. This study proposed a computational model for blood stasis, using a two-fluid principle to track the locations of blood residual over time. The current study applied this novel model to evaluate blood stasis and thrombosis potential in four patient-specific post-TEVAR FLs of type B aortic dissection, with their follow-up in-vivo observations two years after TEVAR. The locations and topologies of residual blood in the FL predicted by the model agreed well with the in-vivo observations of thrombus. In addition, the results corresponded better with clinical observations in terms of interpatient comparison of degree of thrombosis, compared with conventional hemodynamic parameters. The blood stasis model serves as a valuable addition to conventional metrics to better predict thrombosis potential. Collectively, these metrics can provide an efficient non-invasive method for evaluating blood stasis and thrombosis potential in arterial system, and useful guidance for clinicians' operative planning and postoperative evaluation.

The association between fluoroquinolones and aortic dissection and aortic aneurysms: a systematic review and meta-analysis

Previous studies have drawn causal associations between fluoroquinolone use and collagen pathologies including tendon rupture and retinopathy. This meta-analysisattempted to assess the association between fluoroquinolone use and the risk of aortic dissection or aortic aneurysm. A systematic search was performed on Medline, EMBASE, and the Cochrane library. 9 studies were included in final analysis. Primary random-effects meta-analysis of 7 studies, excluding 2 pharmacovigilance studies demonstrated statistically increased odds of aortic dissection (OR, 2.38; 95% CI, 1.71-3.32) aortic aneurysm (OR, 1.98; 95% CI, 1.59-2.48), and aortic aneurysm or dissection (OR, 1.47; 95% CI, 1.13-1.89; I² = 72%) with current use of fluoroquinolones compared to their nonuser counterparts. Based on the "number needed-to-harm" analysis, 7246 (95% CI: 4329 to 14,085) patients would need to be treated with fluoroquinolones for a duration of at least three days in order for one additional patient to be harmed, assuming a population baseline incidence of aortic dissection and aneurysm rupture to be 10 per 100,000 patient-years. With strong statistical association, these findings suggest a causal relationship, warranting future research to elucidate the pathophysiological and mechanistic plausibility of this association. These findings however, should not cease prescription of fluoroquinolones, especially when clinically indicated.

Perceived Need for Psychosocial Support After Aortic Dissection: Cross-Sectional Survey

Background

The gold standard management of aortic dissection, a life-threatening condition, includes multidisciplinary approaches. Although mental distress following aortic dissection is common, evidence-based psychosocial interventions for aortic dissection survivors are lacking.

Objective

The aim of this study is to identify the perceived psychosocial needs of aortic dissection survivors by surveying patients, their relatives, and health professionals to inform the development of such interventions.

Methods

This study used a cross-sectional survey and collected responses from 41 participants (27 patients with aortic dissection, 8 relatives of patients with aortic dissection, and 6 health professionals) on key topics, types of interventions, best timing, anticipated success, and the intended effects and side effects of psychosocial interventions after aortic dissection.

Results

The principal intervention topics were “changes in everyday life” (28/41, 68%, 95% CI 54.5%-82.9%), “anxiety” (25/41, 61%, 95% CI 46.2%-76.2%), “uncertainty” (24/41, 59%, 95% CI 42.9%-73.2%), “tension/distress” (24/41, 59%, 95% CI 43.9%-73.8%), and “trust in the body” (21/41, 51%, 95% CI 35.9%-67.5%). The most commonly indicated intervention types were “family/relative therapy” (21/41, 51%, 95% CI 35%-65.9%) and “anxiety treatment” (21/41, 51%, 95% CI 35%-67.5%). The most recommended intervention timing was “during inpatient rehabilitation” (26/41, 63%, 95% CI 47.6%-77.5%) followed by “shortly after inpatient rehabilitation” (20/41, 49%, 95% CI 32.4%-65%). More than 95% (39/41) of respondents anticipated a benefit from psychosocial interventions following aortic dissection dissection, expecting a probable improvement in 68.6% (95% CI 61.4%-76.2%) of aortic dissection survivors, a worse outcome for 5% (95% CI 2.9%-7.9%), and that 6% (95% CI 1.8%-10.4%) would have negative side effects due to such interventions.

Conclusions

Our findings highlight a substantial need for psychosocial interventions in aortic dissection survivors and indicate that such interventions would be a success. They provide a basis for the development and evaluation of interventions as part of state-of-the-art aortic dissection management.

Timing of thoracic endovascular aortic repair for uncomplicated acute type B aortic dissection and the association with complications

OBJECTIVE

Previous publications have clearly established a correlation between timing of thoracic endovascular aortic repair (TEVAR) and complications after treatment of complicated acute type B aortic dissection (ATBAD). However, the temporal association of TEVAR with morbidity after uncomplicated presentations is poorly understood and has not previously been examined using real-world national data. Therefore, the objective of this analysis was to determine whether TEVAR timing of uncomplicated ATBAD (UATBAD) is associated with postoperative complications.

METHODS

The Vascular Quality Initiative TEVAR and complex endovascular aneurysm repair registry was analyzed from 2010 to 2019. Procedures performed for non-dissection-related disease as well as for ATBAD with malperfusion or rupture were excluded. Because of inherent differences between timing cohorts, propensity score matching was performed to ensure like comparisons. Univariate and multivariable analysis after matching was used to determine differences between timing groups (symptom onset to TEVAR: acute, 1-14 days; subacute, 15-90 days) for postoperative mortality, in-hospital complications, and reintervention.

RESULTS

A total of 688 cases meeting inclusion criteria were identified. After matching 187 patients in each of the 1- to 14-day and 15- to 90-day treatment groups, there were no statistically significant differences between groups. On univariate analysis, the 1- to 14-day treatment group had a higher proportion of cases requiring reintervention within 30 days (15.3%) compared with UATBAD patients undergoing TEVAR within 15 to 90 days (5.2%; P = .02). There was also a difference (P = .007) at 1 year, with 33.8% of the 1- to 14-day UATBAD patients undergoing reintervention compared with 14.5% for the 15- to 90-day group. There were no statistically significant differences on multivariable analysis for long-term survival, complications, or long-term reintervention. There was a trend toward significance (P = .08) with the 1- to 14-day group having 2.3 times the odds of requiring an in-hospital reintervention compared with the 15- to 90-day group.

CONCLUSIONS

Timing of TEVAR for UATBAD does not appear to predict mortality or postoperative complications. However, there is a strong association between repair within 1 to 14 days and higher risk of reintervention. This may in part be related to the 1- to 14-day group's representing an inherently higher anatomic or physiologic risk population that cannot be entirely accounted for with propensity analysis. The role of optimal timing to intervention should be incorporated into future study design of TEVAR trials for UATBAD.

Location of Reentry Tears Affects False Lumen Thrombosis in Aortic Dissection Following TEVAR

Purpose: To report a study that assesses the influence of the distance between the distal end of a thoracic stent-graft and the first reentry tear (SG-FRT) on the progression of false lumen (FL) thrombosis in patients who underwent thoracic endovascular aortic repair (TEVAR). Materials and Methods: Three patient-specific geometrical models were reconstructed from postoperative computed tomography scans. Two additional models were created by artificially changing the SG-FRT distance in patients 1 and 2. In all 5 models, computational fluid dynamics simulations coupled with thrombus formation modeling were performed at physiological flow conditions. Predicted FL thrombosis was compared to follow-up scans. Results: There was reduced false lumen flow and low time-averaged wall shear stress (TAWSS) in patients with large SG-FRT distances. Predicted thrombus formation and growth were consistent with follow-up scans for all patients. Reducing the SG-FRT distance by 30 mm in patient 1 increased the flow and time-averaged wall shear stress in the upper abdominal FL, reducing the thrombus volume by 9.6%. Increasing the SG-FRT distance in patient 2 resulted in faster thoracic thrombosis and increased total thrombus volume. Conclusion: The location of reentry tears can influence the progression of FL thrombosis following TEVAR. The more distal the reentry tear in the aorta the more likely it is that FL thrombosis will occur. Hence, the distal landing zone of the stent-graft should be chosen carefully to ensure a sufficient SG-FRT distance.

Parametric Hemodynamic 4D Flow MRI Maps for the Characterization of Chronic Thoracic Descending Aortic Dissection

BACKGROUND

Systematic evaluation of complex flow in the true lumen and false lumen (TL, FL) is needed to better understand which patients with chronic descending aortic dissection (DAD) are predisposed to complications.

PURPOSE

To develop quantitative hemodynamic maps from 4D flow MRI for evaluating TL and FL flow characteristics.

STUDY TYPE

Retrospective.

POPULATION

In all, 20 DAD patients (age = 60 ± 11 years; 12 male) (six medically managed type B AD [TBAD], 14 repaired type A AD [rTAAD] now with ascending aortic graft [AAo] or elephant trunk [ET1] repair) and 21 age-matched controls (age = 59 ± 10 years; 13 male) were included.

FIELD STRENGTH/SEQUENCE

1.5T, 3T, 4D flow MRI.

ASSESSMENT

4D flow MRI was acquired in all subjects. Data analysis included 3D segmentation of TL and FL and voxelwise calculation of forward flow, reverse flow, flow stasis, and kinetic energy as quantitative hemodynamics maps.

STATISTICAL TESTS

Analysis of variance (ANOVA) or Kruskal-Wallis tests were performed for comparing subject groups. Correlation and Bland-Altman analysis was performed for the interobserver study.

RESULTS

Patients with rTAAD presented with elevated TL reverse flow (AAo repair: P = 0.004, ET1: P = 0.018) and increased TL kinetic energy (AAo repair: P = 0.0002, ET1: P = 0.011) compared to controls. In addition, TL kinetic energy was increased vs. patients with TBAD (AAo repair: P = 0.021, ET1: P = 0.048). rTAAD was associated with higher FL kinetic energy and lower FL stasis compared to patients with TBAD (AAo repair: P = 0.002, ET1: P = 0.024 and AAo repair: P = 0.003, ET1: P = 0.048, respectively).

DATA CONCLUSION

Quantitative maps from 4D flow MRI demonstrated global and regional hemodynamic differences between DAD patients and controls. Patients with rTAAD vs. TBAD had significantly altered regional TL and FL hemodynamics. These findings indicate the potential of 4D flow MRI-derived hemodynamic maps to help better evaluate patients with DAD.

LEVEL OF EVIDENCE

3 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2020;51:1357-1368.

Detection and Hemodynamic Evaluation of Flap Fenestrations in Type B Aortic Dissection with 4D Flow MRI: Comparison with Conventional MRI and CTA

Purpose

The purpose of this study was to compare dissection flap fenestration visualization between 4D flow MRI, clinical MRI/MRA, and clinical CTA studies and describe the presence of hemodynamically active fenestration flow using 4D flow.

Materials and Methods

Nineteen patients with type B dissection (age: 57±5 years) who had undergone standard of-care MRI/MRA of the chest including 4D flow MRI were retrospectively identified. Fourteen of the 19 patients also had CTA performed within 2 years of the MRI/MRA study with no interval surgery. Image review was performed independently by two radiologists. The number of fenestrations (including entry and exit tears), location, and flow directionality were recorded. Differences in the rate of detection between techniques was assessed using a Wilcoxon signed rank test.

Results

4D flow detected more fenestrations relative to MRI/MRA [rev 1: +3 (10%), rev 2: +5 (20%)]. There were similar numbers of fenestrations detected by 4D flow relative to CTA [rev 1: +1 (4%), rev 2: -3 (-12%)]. MRI/MRA detected fewer fenestration relative to CTA in this cohort [rev 1: -6 (-24%), rev 2: -5 (-19%)]. No differences were significant. Combining 4D flow and MRI/MRA resulted in additional fenestration detection. Most fenestrations demonstrated biphasic flow over the cardiac cycle (flow entering false lumen in systole and exiting during diastole, rev 1:18/33, rev 2: 16/30).

Conclusions

4D flow MRI can detect small flap fenestration in type B dissection patients while providing additional information about flow through fenestrations throughout the cardiac cycle relative to CTA and conventional MRI.

Effects of in situ fenestration stent-graft of left subclavian artery on the hemodynamics after thoracic endovascular aortic repair

Objectives

The left subclavian artery during thoracic endovascular aortic repair could be reconstructed by in situ fenestration. This study aims to evaluate the effects of thoracic endovascular aortic repair with in situ fenestration thoracic endovascular aortic repair on the hemodynamics.

Methods

A male patient suffering from aortic dissection is treated by in situ fenestration thoracic endovascular aortic repair and the fenestration stent implanted in the left subclavian artery is partially protruding in the aortic arch for the stability. Two-phase non-Newtonian blood model is applied and three-element Windkessel model is implemented to reproduce physiological pressure waves. Simulations are carried out in three postoperative models to analyze different in situ fenestration thoracic endovascular aortic repair strategies; Case A: the protrusion length of fenestration stent is 23.2 mm representing the clinical postthoracic endovascular aortic repair aorta; Case B: the protrusion length is reduced by half simulating the improved surgery; Case C: the protruding portion is removed to simulate the ideal fenestration.

Results

In Case A, a pressure difference is found on the fenestration stent surface and a blood acceleration phenomenon around the stent is observed. Only 2.36% of the inlet blood flow is assigned to the left subclavian artery. In the improved surgery, the blood supply to the left subclavian artery is elevated to 4.01%. As for the ideal fenestration, a further improvement is observed (6.14%). Moreover, the aortic arch surface exposed to low time-averaged wall shear stress expands significantly when the protrusion length is shortened.

Conclusions

Overall, we conclude that appropriately shortening the protrusion length of the stent-graft may improve the efficacy of in situ fenestration thoracic endovascular aortic repair from the perspective of hemodynamics.

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.

Outcomes of Thoracic Endovascular Aortic Repair for Acute Type B Dissection in Patients With Intractable Pain or Refractory Hypertension

PURPOSE

To compare uncomplicated acute type B aortic dissection (UATBAD) patients with intractable pain/refractory hypertension treated with thoracic endovascular aortic repair (TEVAR) to UATBAD subjects without these features receiving best medical therapy (BMT).

METHODS

Interrogation of the hospital database identified 101 consecutive UATBAD patients admitted between January 2011 and December 2014. Of these, 74 patients (mean age 62±13 years; 44 men) were treated with BMT; the other 27 UATBAD patients (mean age 63±13 years; 17 men) were subsequently treated with TEVAR for intractable pain (24, 89%) and/or refractory hypertension (3, 11%) at a mean 2.4±3.3 days (median 1, range 0-12) after admission. Mixed models were employed to determine differences in centerline measured aortic remodeling. Propensity analysis was employed to mitigate selection bias. Kaplan-Meier methodology was used to estimate reintervention and survival.

RESULTS

The groups were well matched; there was no difference in demographics, comorbidities, or proportion with visceral involvement (70% for TEVAR vs 86% for BMT, p=0.08). There was no significant difference in length of stay (9.6±6.3 for TEVAR vs 10.3±7.8 for BMT, p=0.3), complications (19% for TEVAR vs 24% for BMT, p=0.6), or 30-day mortality (0 for TEVAR vs 7% for BMT, p=0.1). One (4%) TEVAR patient experienced retrograde dissection. BMT resulted in greater mean increase in discharge antihypertensive medications (1.7±1.9 vs 0.7±1.7 for TEVAR, p=0.03), but there was no difference in narcotic utilization. Mean follow-up was greater in the TEVAR group (17.9±16.0 months) compared with BMT patients (11.5±10.8 months, p=0.05). TEVAR significantly improved rates of aortic diameter change (1.5% vs 12.9% for BMT, p=0.007), complete false lumen thrombosis (41% vs 11% for BMT, p=0.004), and true lumen expansion (85% vs 7% for BMT, p<0.01). However, there was no difference in reintervention (25.9% for TEVAR vs 23% for BMT, p=0.2) or survival (log-rank p=0.8).

CONCLUSION

TEVAR for UATBAD with intractable pain/refractory hypertension is safe but offers no short-term outcome advantage when compared to UATBAD patients without these features receiving BMT. A significant improvement in aortic remodeling was identified after TEVAR. The potential long-term reintervention and aorta-related mortality benefits of this favorable remodeling have yet to be defined and randomized trials are warranted.

Time-Resolved Three-Dimensional Contrast-Enhanced Magnetic Resonance Angiography in Patients with Chronic Expanding and Stable Aortic Dissections

Objective

To prospectively evaluate our hypothesis that three-dimensional time-resolved contrast-enhanced magnetic resonance angiography (TR-MRA) is able to detect hemodynamic alterations in patients with chronic expanding aortic dissection compared to stable aortic dissections.

Materials and Methods

20 patients with chronic or residual aortic dissection in the descending aorta and patent false lumen underwent TR-MRA of the aorta at 1.5 T and repeated follow-up imaging (mean follow-up 5.4 years). 7 patients showed chronic aortic expansion and 13 patients had stable aortic diameters. Regions of interest were placed in the nondissected ascending aorta and the false lumen of the descending aorta at the level of the diaphragm (FL-diaphragm level) resulting in respective time-intensity curves.

Results

For the FL-diaphragm level, time-to-peak intensity and full width at half maximum were significantly shorter in the expansion group compared to the stable group (p = 0.027 and p = 0.003), and upward and downward slopes of time-intensity curves were significantly steeper (p = 0.015 and p = 0.005). The delay of peak intensity in the FL-diaphragm level compared to the nondissected ascending aorta was significantly shorter in the expansion group compared to the stable group (p = 0.01).

Conclusions

3D TR-MRA detects significant alterations of hemodynamics within the patent false lumen of chronic expanding aortic dissections compared to stable aortic dissections.

Aortic dissection

Aortic dissection is a life-threatening condition caused by a tear in the intimal layer of the aorta or bleeding within the aortic wall, resulting in the separation (dissection) of the layers of the aortic wall. Aortic dissection is most common in those 65-75 years of age, with an incidence of 35 cases per 100,000 people per year in this population. Other risk factors include hypertension, dyslipidaemia and genetic disorders that involve the connective tissue, such as Marfan syndrome. Swift diagnostic confirmation and adequate treatment are crucial in managing affected patients. Contemporary management is multidisciplinary and includes serial non-invasive imaging, biomarker testing and genetic risk profiling for aortopathy. The choice of approach for repairing or replacing the damaged region of the aorta depends on the severity and the location of the dissection and the risks of complication from surgery. Open surgical repair is most commonly used for dissections involving the ascending aorta and the aortic arch, whereas minimally invasive endovascular intervention is appropriate for descending aorta dissections that are complicated by rupture, malperfusion, ongoing pain, hypotension or imaging features of high risk. Recent advances in the understanding of the underlying pathophysiology of aortic dissection have led to more patients being considered at substantial risk of complications and, therefore, in need of endovascular intervention rather than only medical or surgical intervention.

Contemporary endovascular treatment of type B aortic dissection in China

OBJECTIVE

Endovascular stent-grafts have been used in China to treat type B aortic dissection since 1999, and there is a plethora of cohort studies in the contemporary literature. The aim of this review was to analyse the published results of endovascular treatment for type B aortic dissection in China.

METHOD

A systematic literature review of all published literature from January 1999 to October 2014 on endovascular treatment of type B aortic dissection in China was undertaken using PubMed, Medline, and the Chinese National Knowledge Infrastructure databases.

RESULTS

Seventy papers were retrieved (4 English, 66 Chinese) with a total of 4208 patients; 3396 (80.7%) were male, and the mean age ranged from 43 to 65 years. Procedural success was reported in 99.4% ± 1.7%. Complications were reported in 14.6% ± 11.1%, with major complications in 1.7% ± 2.9%, and the most devastating neurologic complications in 1.1% ± 2.2% (stroke 0.9% ± 2.4%, paraplegia 1.5% ± 0.7%). Postoperative endoleak occurred in 8.1% ± 7.6%. The 30-day postoperative mortality was 2.4% ± 3.3%. During follow-up, false-lumen thrombosis occurred in 92.1% ± 11.7%. Reintervention was performed in 1.3% ± 3.3%. The incidence of proximal and distal stent-graft-induced new entry was 0.5% ± 1.3% and 0.9% ± 2.7%, respectively, with endoleak in 2.7% ± 4.4% and mortality of 2.2% ± 3.2%.

CONCLUSIONS

Current evidence suggests that use of endovascular stent-grafts for type B aortic dissection in China is feasible and safe with low rates of perioperative complications and short-term mortality. However, a standardised reporting system and long-term follow-up data are lacking.

Thoracic Endovascular Aortic Repair for Traumatic Thoracic Aortic Injury: A Single-Center Initial Experience

BACKGROUND

Several publications have documented the technical feasibility and efficacy of stent grafting for aortic injuries. We report short- and mid-term results of thoracic endovascular repair with covered stent grafts for type B blunt thoracic aortic injury.

METHODS

We performed a retrospective review of patients who had sustained blunt thoracic aortic injuries. From January 2010 to March 2014, 13 patients (12 men and 1 woman) were admitted and treated in our department for type B thoracic aortic injury. The patients' ages ranged from 19 to 62 years. Traffic accidents were responsible for 10 of the 13 blunt thoracic aortic injuries, and the remainder was caused by blunt trauma from falls. Medical records were examined to identify the clinical outcomes of the procedures, and follow-up computed tomography scans were reviewed to document the efficacy of thoracic endovascular aortic repair.

RESULTS

Endovascular stent grafting was technically successful in all cases, and no paraplegia or stroke-like events were reported. No major cardiac, neurologic, or peripheral vascular complications were observed during early or late follow-up. None of the patients died from procedure-related complications.

CONCLUSIONS

Our single-center experience demonstrates the feasibility of performing endovascular repair for type B blunt aortic injury. As experience with endovascular surgery accumulates, this method of treatment promises to become the first-choice option for repairing this type of aortic injury, with less associated morbidity and mortality relative to conventional surgical repair.

Outcomes of Patients With Acute Type B (DeBakey III) Aortic Dissection: A 13-Year, Single-Center Experience

Background—

Aortic dissection remains the most common aortic catastrophe. In the endovascular era, the management of acute type B aortic dissection (ATBAD) is undergoing dramatic changes. The aim of this study is to evaluate the long-term outcomes of patients with ATBAD who were treated at our center over a 13-year period.

Methods and Results—

We reviewed patients with ATBAD between 2001 and 2014, analyzing variables based on status (complicated [c] versus uncomplicated [u]) and treatment modalities. We defined cATBAD as rupture, expansion of diameter on imaging during the admission, persistent pain, or clinical malperfusion leading to a deficit in cerebral, spinal, visceral, renal, or peripheral vascular territories at presentation or during initial hospitalization. Postoperative outcomes were defined as deficits not present before the intervention. Outcomes were compared between the groups by use of Kaplan-Meier and descriptive statistics. We treated 442 patients with ATBAD. Of those 442, 60.6% had uATBAD and were treated medically, and 39.4% had cATBAD, of whom 39.0% were treated medically to 30.0% with open repair, 21.3% with thoracic endovascular aortic repair, and 9.7% with other open peripheral procedures. Intervention-free survival at 1 and 5 years was 84.8% and 62.7% for uATBAD, 61.8% and 44.0% for cATBAD-medical, 69.2% and 47.2% for cATBAD-open, and 68.0% and 42.5% for cATBAD–thoracic endovascular aortic repair, respectively (P=0.001). Overall survival was significantly related primarily to complicated presentation.

Conclusions—

In our experience, early and late outcomes of ATBAD were dependent on the presence of complications, with cATBAD faring worse. Although uATBAD was associated with favorable early survival, late complications still occurred, mandating radiographic surveillance and open or endovascular interventions. Prospective trials are required to better determine the optimal therapy for uATBAD.

Complicated Acute Aortic Syndromes Affecting the Descending Thoracic Aorta: Endovascular Treatment Compared With Open Repair

BACKGROUND

For patients with complicated acute thoracic aortic syndromes, endovascular treatment, when feasible, is preferred over open surgery. However, there are limited data on the long-term benefits of endovascular treatment in complicated acute aortic syndromes affecting the descending thoracic aorta.

HYPOTHESIS

The endovascular treatment is expected to have more favorable long-term mortality and fewer late reintervention in complicated acute thoracic aortic syndromes.

METHODS

Of 155 consecutive patients with acute aortic syndromes, 94 met the inclusion criteria of the study; 63 underwent endovascular repair (group 1) and 31 underwent open repair (group 2). Patients with a diagnosis of acute aortic syndrome localized in the descending thoracic aorta distal to the emergence of the left subclavian artery, complicated by rupture, malperfusion syndrome, and/or acute aortic expansion, were included. Indications for repair of the descending thoracic aorta included impending rupture in 70.2%, malperfusion syndrome in 29.8%, and persistence of pain with aortic expansion (aortic diameter >40 mm) in 2 patients.

RESULTS

During the follow-up period (63.0 ± 24.6 months), the cumulative survival free from cardiovascular death rates at 5 years was 92.0% and 51.4% in group 1 and 2, respectively (log rank P = 0.0001). Late mortality related to the aorta was 1.6% with thoracic endovascular aortic repair and 0% with surgical treatment.

CONCLUSIONS

Endovascular treatment in patients with complicated acute thoracic aortic syndromes localized at the descending thoracic aorta is feasible and safe, with a lower rate of early complications and similar long-term benefits when compared with surgical treatment.

[Acute aortic diseases. Diagnostic imaging and therapy]

Diagnostic imaging is crucial in the work-up of acute aortic diseases. Current imaging algorithms enable radiologists differentiating the various entities with subsequent clinically relevant treatment options. Within this educational overview we focus on non-traumatic acute aortic disease. Recent developments of cross sectional imaging are summarized. As for acute aortic disease, we discuss dissections, intramural hematoma, penetrating aortic ulcer, and aortitis. Current treatment options are presented.