The diagnosis and management of aortic dissection

Early Results of a Single-Center Prospective Clinical Trial: In Situ Fenestration System for Aortic Dissection

Objectivestudy aims to assess the clinical efficacy, technical features, and early follow-up outcomes of aortic arch dissection (AD) requiring left subclavian artery (LSA) reconstruction using the aorta arch stent-graft system combined with the endovascular needle system for in situ fenestration.Methods and ResultsEight patients with AD were enrolled in this clinical trial after rigorous screening between July 2021 and August 2022. The 8 patients who participated in this trial were male, with a mean age of 62.0 ± 8.3 years. The total operative time was 148.38 ± 35.06 minutes, and the mean hospitalization time was 11.4 ± 4.4 days. A total of 12 aortic stents were implanted in the 8 patients, and branching stents were implanted in the LSA in all patients. No cases of delayed endoleak occurred. There were no stent- or aorta-related deaths. The 2 deaths that did occur were confirmed to have been due to causes outside of the aorta and were unrelated to the thoracic endovascular aortic repair procedure, with a 1-year stent patency rate of 100%.ConclusionsWe believe that this trial of in situ fenestration achieved satisfactory early results, with reasonable postprocedural stent patency and patient survival, and there were no endoleaks requiring intervention during follow-up. However, long-term follow-up is needed to validate the findings of this trial.Trial registrationClinicalTrials.gov PRS Protocol Registration and Results System (URL: Home - ClinicalTrials.gov, NCT05126446).

Exploratory analysis of Type B Aortic Dissection (TBAD) segmentation in 2D CTA images using various kernels

Type-B Aortic Dissection is a rare but fatal cardiovascular disease characterized by a tear in the inner layer of the aorta, affecting 3.5 per 100,000 individuals annually. In this work, we explore the feasibility of leveraging two-dimensional Convolutional Neural Network (CNN) models to perform accurate slice-by-slice segmentation of true lumen, false lumen and false lumen thrombus in Computed Tomography Angiography images. The study performed an exploratory analysis of three 2D U-Net models: the baseline 2D U-Net, a variant of U-Net with atrous convolutions, and a U-Net with a custom layer featuring a position-oriented, partially shared weighting scheme kernel. These models were trained and benchmarked against a state-of-the-art baseline 3D U-Net model. Overall, our U-Net with the VGG19 encoder architecture achieved the best performance score among all other models, with a mean Dice score of 80.48% and an IoU score of 72.93%. The segmentation results were also compared with the Segment Anything Model (SAM) and the UniverSeg models. Our findings indicate that our 2D U-Net models excel in false lumen and true lumen segmentation accuracy while achieving lower false lumen thrombus segmentation accuracy compared to the state-of-the-art 3D U-Net model. The study findings highlight the complexities involved in developing segmentation models, especially for cardiovascular medical images, and emphasize the importance of developing lightweight models for real-time decision-making to improve overall patient care.

Computational Investigation of the Hemodynamic Effects of the Location of a Re-Entry Tear in Uncomplicated Type B Aortic Dissection

This study aimed to examine the hemodynamic modifications in uncomplicated type B aortic dissection in relation to the location of re-entry tears using a computational fluid dynamics simulation. The geometry of uncomplicated type B aortic dissection was reconstructed using computed tomography images. Subsequently, 10 virtual models were artificially generated with re-entry tears at various locations. The simulation results indicated that most models with re-entry tears had lower pressure and wall shear stress than those without re-entry tears. The overall pressure distribution of the true lumen was greater than that of the models without re-entry tears when the re-entry tear was placed at the end of the false lumen. Furthermore, the recirculation phenomenon in the false lumen was reduced as the re-entry tear was relocated to the distal region of the aorta. To determine whether and how to perform fenestration surgery in patients with uncomplicated type B aortic dissection, these computational results can be used as supplemental indicators. However, further validation in a larger number of patients through additional investigation is necessary.

Biomimetic-Structured Cobalt Nanocatalyst Suppresses Aortic Dissection Progression by Catalytic Antioxidation

As one of the most lethal cardiovascular diseases, aortic dissection (AD) is initiated by overexpression of reactive oxygen species (ROS) in the aorta that damages the vascular structure and finally leads to massive hemorrhage and sudden death. Current drugs used in clinics for AD treatment fail to efficiently scavenge ROS to a large extent, presenting undesirable therapeutic effect. In this work, a nanocatalytic antioxidation concept has been proposed to elevate the therapeutic efficacy of AD by constructing a cobalt nanocatalyst with a biomimetic structure that can scavenge pathological ROS in an efficient and sustainable manner. Theoretical calculations demonstrate that the antioxidation reaction is catalyzed by the redox transition between hydroxocobalt(III) and oxo-hydroxocobalt(V) accompanied by inner-sphere proton-coupled two-electron transfer, forming a nonassociated activation catalytic cycle. The efficient antioxidation action of the biomimetic nanocatalyst in the AD region effectively alleviates oxidative stress, which further modulates the aortic inflammatory microenvironment by promoting phenotype transition of macrophages. Consequently, vascular smooth muscle cells are also protected from inflammation in the meantime, suppressing AD progression. This study provides a nanocatalytic antioxidation approach for the efficient treatment of AD and other cardiovascular diseases.

Thoracic aortic dissection presenting with bilateral haemothoraces: a potentially missed diagnosis

Thoracic aortic dissection is a life-threatening diagnosis, which should not be missed. We present a case in which a patient who presented to the emergency department with chest pain was assessed and referred for admission for treatment of pneumonia, due to misinterpretation of a chest radiograph finding. The patient was re-reviewed and subsequently underwent further investigation, which confirmed aortic dissection. She underwent emergency thoracic endovascular aortic graft repair with stent graft insertion. This case demonstrates haemothorax as an uncommon complication of aortic dissection.

Semi-supervised aortic dissections segmentation: A time-dependent weighted feedback fusion framework

The segmentation of true lumen (TL) and false lumen (FL) plays an important role in the diagnosis and treatment of aortic dissection (AD). Although the deep learning methods have achieved remarkable performance for this task, a large number of labeled data are required for training. In order to alleviate the burden of doctors' labeling, in this paper, a novel time-dependent weighted feedback fusion based semi-supervised aortic dissections segmentation framework is proposed by effectively leveraging the unlabeled data. A feedback network is additionally extended to encode the predicted output from the backbone network into high-level feature space, which is then fused with the original feature information of the image to fix previous potential mistakes, thereby segmentation accuracy is improved iteratively. To utilize both labeled data and unlabeled data, the fused feature space flows into the network again to generate the second feedback and make sure consistency with the previous one. The utilization of image feature space provides better robustness and accuracy for the proposed structure. Experiments show that our method outperforms five existing state-of-the-art semi-supervised segmentation methods on both a type-B AD dataset and a public dataset.

A Devastating Tear: Atypical Presentation of Aortic Dissection Discovered on Echocardiography

Acute aortic dissection (AAD) is a serious medical problem that requires prompt recognition in order to prevent deadly complications. Nevertheless, making the diagnosis can often be challenging. The clinical signs and symptoms of AAD may vary depending on the location of the dissection, leading to subtle differences in the initial patient presentation. Moreover, the classically described signs of blood pressure disparity, pulse deficit, or the presence of a diastolic murmur are often absent. Here, we report a challenging case of AAD in which the patient presented with acute substernal chest pain that resolved after a short period and was associated with hypotension. His bilateral upper and lower extremities were well perfused with symmetrical, palpable pulses. The initial point-of-care ultrasound (POCUS) showed a small pericardial effusion, and a follow-up echocardiogram revealed an ascending aortic flap with aortic root dilation diagnostic of AAD. Our aim is to shed light on the challenge of diagnosing AAD.

Risk factors for early death after surgery in patients with acute Stanford type A aortic dissection: A systematic review and meta-analysis

BACKGROUND

There are many risk factors related to early death after surgery among patients with acute Stanford type A aortic dissection (ATAAD) that have been analyzed in previous studies, but no evidence-based study has been conducted to confirm these risk factors.

AIMS

The aims of this study were to investigate risk factors for early death after surgery in patients with ATAAD via systematic review and meta-analysis and assess evidence-based strategies for preventing adverse events.

METHODS

The protocol for this study was prospectively registered with PROSPERO (CRD 42022332772). The authors systematically searched PubMed, Ovid, Scopus, Web of Science and Cochrane Library following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines from database construction to May 2021. Studies that met the selection criteria were determined by two independent researchers, and the odds ratios (ORs) and 95% confidence intervals (95% CIs) were reported for the risk factors and were pooled using Stata 15.0.

RESULTS

A total of 23 studies including 5510 patients met the inclusion criteria, and 10 risk factors were analyzed in this meta-analysis. The preoperative risk factors for early death after surgery in patients with ATAAD were age [(OR: 1.03, 95% CI (1.01, 1.06)], male sex [(OR: 1.43, 95% CI (1.06, 1.92)], shock [(OR: 1.91, 95% CI (1.06, 3.45)], malperfusion [(OR: 3.45, 95% CI (2.24, 5.31)] and cardiac tamponade [(OR: 3.89, 95% CI (1.17, 12.98)].

CONCLUSION

Patients with ATAAD who have an older age, male sex, shock, malperfusion and cardiac tamponade have a higher risk for early death after surgery. However, more highly homogenous studies are needed to demonstrate these results. Clinical staff should pay more attention to these factors and take individual actions to reduce mortality after surgery in patients with ATAAD.

Risk Factors Associated with Poor Prognosis in Patients with Stanford Type B Aortic Dissection after Thoracic Endovascular Aortic Repair

BACKGROUND

The aim of the study was to analyze the clinical characteristics of patients with Stanford type B aortic dissection (TBAD) and risk factors for poor prognosis after thoracic endovascular aortic repair (TEVAR).

METHODS

Clinical records for patients with TBAD presenting to a medical center between March 1, 2012 and July 31, 2020 were reviewed. Clinical data including demographics, comorbidities, and postoperative complications were obtained from electronic medical records. Comparative analysis and subgroup analysis were performed. A logistic regression model was used to analyze prognostic factors in patients with TBAD after TEVAR.

RESULTS

TEVAR was performed on all 170 patients with TBAD, and poor prognosis was identified in 28.2% (48/170) of cases. Patients with a poor prognosis were younger (38.5 [32.0, 53.8] years vs. 55.0 [48.0, 62.0] years, P < 0.001), had higher systolic blood pressure (SBP) (138.5 [127.8, 152.8] mm Hg vs. 132.0 [120.8, 145.3] mm Hg, P = 0.013) and more complicated aortic dissection patients (19 [60.4] vs. 71 [41.8], P = 0.029) than those without a poor prognosis. According to the results of binary logic regression analysis, the possibility of a poor prognosis after TEVAR decreased with each 10 years increase in age (odds ratio: 0.464, 95% confidence interval: 0.327-0.658, P < 0.001).

CONCLUSIONS

There is an association between younger age and a poor prognosis after TEVAR in patients with TBAD, with the condition that those with poor prognoses have higher SBP and more complicated cases. In younger patients, postoperative follow-up should be more frequent, and complications should be managed in time.

Human cytomegalovirus-encoded microRNAs expression profile in plasma of patients with aortic dissection

BACKGROUND

Aortic dissection (AD) is a rare disease with high mortality for which no effective diagnostic biomarkers are available. Human cytomegalovirus (HCMV) infection is an important cause of the occurrence and progression of many diseases, but the relationship between HCMV infection and AD is not clear.

METHODS

In this study, we first used quantitative reverse transcription polymerase chain reaction (qRT-PCR) to determine the expression profile of 25 HCMV-encoded microRNAs (HCMV miRNAs) in the plasma within a training set consisting of 20 AD patients and 20 healthy controls. Then, abnormal expressed HCMV miRNAs were verified in a validation set of 12 AD patients and 12 healthy controls. In addition, HCMV infection was detected in the third cohort consisting of 20 AD patients and 20 healthy controls.

RESULTS

The 95% quantile of the expression levels of HCMV miRNAs in the training set was used as the threshold for distinction between AD patients and healthy controls. The proportion of individuals with high level of five types of HCMV miRNAs was significantly different between AD patients and healthy controls. In the validation set, only the proportion of individuals with high levels of hcmv-miR-UL112-5p and hcmv-miR-UL22A-5p, two of the five HCMV miRNAs obtained in the preliminary screening, showed significant difference between AD patients and healthy controls. In the third cohort, there was no significant difference in HCMV DNA levels and anti-HCMV IgG concentrations between AD patients and healthy controls.

CONCLUSIONS

The HCMV miRNAs levels in plasma differed in AD patients and healthy controls. This finding may contribute to a further understanding of the relationship between HCMV infection and AD and are worthy of future research on the diagnosis and etiology of AD.

Fatal association of COVID-19 and acute type A aortic dissection

Type A aortic dissection is a catastrophic event that requires prompt diagnosis and intervention to save the patient. It seems that type A aortic dissection in COVID-19 patients has increased severity, and even with immediate diagnosis, it has a high mortality.

Criteria for endovascular intervention in type B aortic dissection

BACKGROUND

The use of thoracic endovascular aortic repair (TEVAR) for the management of uncomplicated type B aortic dissection (un-TBAD) remains controversial. There is a lack of consensus over whether pre-emptive TEVAR should be carried out in patients with un-TBAD at risk of progression to complicated TBAD. We present a review of current evidence and seek to suggest criteria where endovascular intervention in un-TBAD may prove beneficial relative to pharmacotherapy alone.

METHODS AND MATERIALS

PubMed and Cochrane databases were searched using terms including: type B aortic dissection, risk factors, medical therapy, TEVAR, false lumen (FL) expansion, and mortality. Papers were selected based on title and abstract.

RESULTS

Optimal medical therapy remains the mainstay treatment for patients with un-TBAD, however, patients with un-TBAD present with varying degrees of disease progression risk. Factors such as age, aortic morphology, history of connective tissue disorders, FL thrombosis, and aortic branch involvement may potentiate progression from un-TBAD to complicated TBAD. Short- and long-term outcomes associated with TEVAR for TBAD remain promising.

CONCLUSION

Pre-emptive TEVAR may be beneficial in patients with un-TBAD presenting with the above factors, however, further prospective research into the optimal timing for TEVAR in un-TBAD is required.

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.

Application value of preoperative dual-source computed tomography in assessing the rupture site of thoracic aortic dissection

Objective

To investigate the application value of dual-source computed tomography (DSCT) in preoperative assessment the rupture site of an thoracic aortic dissection (TAD).

Methods

A retrospective analysis of preoperative DSCT, multislice computed tomography (MSCT), and transthoracic echocardiography (TTE) results of 150 patients with suspected TAD in our hospital was conducted, and the intraoperative findings or interventional treatment results were used as the diagnostic gold standard.

Results

Of all 150 suspected TAD patients, 123 patients were confirmed to have TAD. The rupture site of TAD was in the ascending aorta in 46 patients, in the aortic arch in 13 patients, and in the descending aorta in 64 patients. The sensitivity of DSCT, MSCT, and TTE for locating the rupture site of the TAD was 100%, 93.5%, and 89.5%, respectively, and the specificity was 100%, 88.9%, and 81.5%. The differences were statistically significant. The distance between the actual rupture site and the one diagnosed by DSCT, MSCT, and TTE was 1.9 ± 1.2 mm, 5.1 ± 2.7 mm, and 7.8 ± 3.5 mm, respectively; the latter two were significantly worse than DSCT. The size of the rupture site diagnosed by DSCT, MSCT, and TTE was 1.5 ± 0.8 cm, 1.7 ± 0.9 cm, and 1.9 ± 1.0 cm, respectively. The size of the rupture site diagnosed by DSCT was not significantly different from the actual size of 1.4 ± 0.7 cm, while those by MSCT and TTE were.

Conclusion

DSCT has high sensitivity and specificity in diagnosing the rupture site of TAD and can clearly locate the rupture site. It can be a preferred imaging method for TAD.

Exploring the Correlation and Protective Role of Diabetes Mellitus in Aortic Aneurysm Disease

Introduction: Diabetes mellitus is recognised as a significant risk factor for cardiovascular and peripheral vascular disease, as the abnormal metabolic state increases the risk for atherosclerosis, occlusive arterial disease and vascular dysfunction. There have been reports of potential association across the literature that illustrates a link between diabetes mellitus and aortic aneurysm, with the former having a protective role on the development of the latter.

Methods: A thorough literature search was performed through electronic databases, to provide a comprehensive review of the study's reporting on the association of diabetes mellitus and aortic aneurysm, discussing the mechanisms that have been reported; furthemore, we reviewed the reports of the impact of oral hypoglycameic agents on aortic aneurysms.

Results: Various proposed mechanisms are involved in this protective process including endothelial dysfunction, chronic hyperglycemia and insulin resistance. The evidence suggests a negative association between these disease process, with prevelance of diabetes mellitus resulting in lower rates of aortic aneurysm, via its protective mechanistic action. The increase in advanced glycation end products, increased arterial stiffness and vascular remodelling seen in diabetes, was found to have a profound impact on aneurysm development, its slow progression and lower rupture rate in these individuals. This review has also highlighted the role of oral hypoglycaemic agents having a protective effect against AA disease.

Conclusion: A decrease in development, progression and mortality from aortic aneurysms as well as reduced rates of dissection, have been observed in those with diabetes. This review has provided a comprehensive insight on the effect of diabetes and its physiological processes, and elements of its con-committant treatment, having a protective role against these aortic diseases.

A Cascaded Deep Learning Framework for Detecting Aortic Dissection Using Non-contrast Enhanced Computed Tomography

Aortic dissection (AD) is a rare but potentially fatal disease with high mortality. The aim of this study is to synthesize contrast enhanced computed tomography (CE-CT) images from non-contrast CT (NCE-CT) images for detecting aortic dissection. In this paper, a cascaded deep learning framework containing a 3D segmentation network and a synthetic network was proposed and evaluated. A 3D segmentation network was firstly used to segment aorta from NCE-CT images and CE-CT images. A conditional generative adversarial network (CGAN) was subsequently employed to map the NCE-CT images to the CE-CT images non-linearly for the region of aorta. The results of the experiment suggest that the cascaded deep learning framework can be used for detecting the AD and outperforms CGAN alone.

ImageTBAD: A 3D Computed Tomography Angiography Image Dataset for Automatic Segmentation of Type-B Aortic Dissection

Type-B Aortic Dissection (TBAD) is one of the most serious cardiovascular events characterized by a growing yearly incidence, and the severity of disease prognosis. Currently, computed tomography angiography (CTA) has been widely adopted for the diagnosis and prognosis of TBAD. Accurate segmentation of true lumen (TL), false lumen (FL), and false lumen thrombus (FLT) in CTA are crucial for the precise quantification of anatomical features. However, existing works only focus on only TL and FL without considering FLT. In this paper, we propose ImageTBAD, the first 3D computed tomography angiography (CTA) image dataset of TBAD with annotation of TL, FL, and FLT. The proposed dataset contains 100 TBAD CTA images, which is of decent size compared with existing medical imaging datasets. As FLT can appear almost anywhere along the aorta with irregular shapes, segmentation of FLT presents a wide class of segmentation problems where targets exist in a variety of positions with irregular shapes. We further propose a baseline method for automatic segmentation of TBAD. Results show that the baseline method can achieve comparable results with existing works on aorta and TL segmentation. However, the segmentation accuracy of FLT is only 52%, which leaves large room for improvement and also shows the challenge of our dataset. To facilitate further research on this challenging problem, our dataset and codes are released to the public (Dataset, 2020).

Management of Acute, Complicated Type B Aortic Dissection

Management of acute complicated Type B aortic dissection (TBAD) requires a multidisciplinary approach with careful evaluation and understanding of the complicating features. Patients who present with or progress to a complicated TBAD must be triaged and managed rapidly due to the high morbidity and mortality even in the presence of optimal medical, endovascular, and open therapies. When required, invasive therapies can be broken down most simply into four treatments: thoracic endograft placement, aortic fenestration, branch vessel stenting, and open repair. However, which therapy to offer and in which order is often unclear. In this review, focus is placed on clinical presentation, diagnosis, and explanation for one or a combination of these therapies. In addition, contraindications as well as expected outcomes, complications, and adjunct therapies will be reviewed. The advent of advanced endovascular techniques has certainly improved the immediate morbidity and mortality of acute complicated TBAD; however, much remains to learn about patient selection and therapeutic intervention performed.

Protective effect of dexmedetomidine on perioperative myocardial injury in patients with Stanford type-A aortic dissection

OBJECTIVE

To investigate the protective effect and mechanism of dexmedetomidine (Dex) on perioperative myocardial injury in patients with Stanford type-A aortic dissection (AD).

METHODS

Eighty-six patients with Stanford type-A AD were randomly divided into Dex and control groups, with 43 cases in each group. During the surgery, the control group received the routine anesthesia, and the Dex group received Dex treatment based on routine anesthesia. The heart rate (HR) and mean arterial pressure (MAP) were recorded before Dex loading (t0), 10 min after Dex loading (t1), at the skin incision (t2), sternum sawing (t3), before cardiopulmonary bypass (t4), at the extubation (t5), and at end of surgery (t6). The blood indexes were determined before anesthesia induction (T0) and postoperatively after 12h (T1), 24h (T2), 48h (T3), and 72h (T4).

RESULTS

At t2 and t3, the HR and MAP in the Dex group were lower than in the control group (P < 0.05). Compared with the control group, in the Dex group at T1, T2, and T3, the serum creatine kinase-MB, cardiac troponin-I, C-reactive protein, and tumor necrosis factor-α levels were decreased, and the interleukin-10 level, the serum total superoxide dismutase, and total anti-oxidant capability increased, while the myeloperoxidase and malondialdehyde levels decreased (all P < 0.05).

CONCLUSIONS

Dex treatment may alleviate perioperative myocardial injury in patients with Stanford type-A AD by resisting inflammatory response and oxidative stress.

Development of a test method to investigate mode II fracture and dissection of arteries

The current study presents the development and implementation of a bespoke experimental technique to generate and characterise mode II crack initiation and propagation in arterial tissue. The current study begins with a demonstration that lap-shear testing of arterial tissue results in mixed mode fracture, rather than mode II. We perform a detailed computational design of a bespoke experimental method (which we refer to as a shear fracture ring test (SFRT)) to robustly and repeatably generate mode II crack initiation and propagation in arteries. This method is based on generating a localised region of high shear adjacent to a cylindrical loading bar. Placement of a radial notch in this region of high shear stress is predicted to result in a kinking of the crack during a mode II initiation and propagation of the crack over a long distance in the circumferential (c)-direction along the circumferential-axial (c-a) plane. Fabrication and experimental implementation of the SFRT on excised ovine aorta specimens confirms that the bespoke test method results in pure mode II initiation and propagation. We demonstrate that the mode II fracture strength along the c-a plane is eight times higher than the corresponding mode I strength determined from a standard peel test. We also calibrate the mode II fracture energy based on our measurement of crack propagation rates. The mechanisms of fracture uncovered in the current study, along with our quantification of mode II fracture properties have significant implications for current understanding of the biomechanical conditions underlying aortic dissection.

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.

Mercaptoethanol Protects the Aorta from Dissection by Inhibiting Oxidative Stress, Inflammation, and Extracellular Matrix Degeneration in a Mouse Model

Background

The aims of this study were to investigate the effects of mercaptoethanol treatment on the expression of mediators of oxidative stress, inflammation, and extracellular matrix (ECM) degeneration in a mouse aortic dissection (AD) model.

Material/Methods

Twenty-four 8-month-old C57BL/6J mice were divided into three groups and studied for two weeks: 1) the aortic dissection (AD) Model group (N=8) underwent intraperitoneal injection of angiotensin II (Ang II) (5 ml/kg) three times every 24 h; 2) the mercaptoethanol Treated group (N=8) were given oral mercaptoethanol (2.5 mM); the Normal group (N=8) underwent intraperitoneal injection of noradrenaline (5 mg/kg) three times every 24 h. Sections of mouse aorta were prepared for histology with hematoxylin and eosin (H&E) staining; immunohistochemistry was performed to detect levels of: nuclear factor (erythroid-derived 2)-like 2 (NFE2L2), nuclear factor κB (NF-κB), p65, superoxide dismutase-1 (SOD1), glutamate cysteine ligase catalytic subunit (GCLC), tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and matrix metalloproteinase-9 (MMP9). Quantitative reverse transcription-polymerase chain reaction (RT-PCR) evaluated mRNA expression of SOD1, GCLC, TNF-α, IL-1β, and MMP9.

Results

Mercaptoethanol treatment inhibited Ang II-induced aortic dissection in AD mice, as shown histologically. Mercaptoethanol treatment reduced the expression levels of NFE2L2, NF-κB, p65, TNF-α, IL-1β and increased the expression levels of SOD1, MMP9, and GCLC.

Conclusions

In an AD mouse model, mercaptoethanol treatment inhibited thoracic and abdominal aortic dissection and reduced aortic tissue expression of mediators of oxidative stress and inflammation and increased the activation of ECM signaling pathways.

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.

Localized Aortic Root Dissection with a Superior Mesenteric Artery Aneurysm

In this study, the case of a 46-year-old female patient with localized aortic root dissection and a superior mesenteric artery (SMA) aneurysm is described. Computed tomographic angiography could not clearly delineate an intimal flap in the aortic root, but it detected SMA aneurysm, which implied the presence of a vulnerability of the aortic wall. Finally, transesophageal echocardiography (TEE) evidently showed the intimal flap localized in the aortic root. The present case suggests that TEE is of paramount importance for detecting localized aortic root dissection. In addition, a coexisting vascular lesion may be a clue to diagnose another vascular lesion.

Ascending aortic dissection presented as inferior myocardial infarction: a clinical and diagnostic mimicry

Acute ST segment elevation myocardial infarction (STEMI) is typically associated with acute coronary thrombosis or plaque rupture. Rarely, STEMI can be associated with ascending aortic dissection, which represents the majority of acute aortic syndrome aetiologies and carries dreadful outcomes. Routine cardiac intervention with emergent cardiac catheterisation may lead to a higher mortality rate in this group of patients. We present a case of painless inferior STEMI in the setting of ascending aortic dissection. The patient had an inferior STEMI due to the involvement of the right coronary artery as an extension of the ascending aortic dissection. In this era of protocol-driven practice and the pressure to fulfil quality measures, we aim to alert emergency physicians, cardiologists and interventionalists of the possible presentation of painless ascending aortic dissection as an STEMI. The two pathologies characterise by crucial differences in their initial and ultimate management.

Use of real-time three-dimensional transesophageal echocardiography in type A aortic dissections: advantages of 3D TEE illustrated in three cases

Stanford type A aortic dissections often present to the hospital requiring emergent surgical intervention. Initial diagnosis is usually made by computed tomography; however transesophageal echocardiography (TEE) can further characterize aortic dissections with specific advantages: It may be performed on an unstable patient, it can be used intra-operatively, and it has the ability to provide continuous real-time information. Three-dimensional (3D) TEE has become more accessible over recent years allowing it to serve as an additional tool in the operating room. We present a case series of three patients presenting with type A aortic dissections and the advantages of intra-operative 3D TEE to diagnose the extent of dissection in each case. Prior case reports have demonstrated the use of 3D TEE in type A aortic dissections to characterize the extent of dissection and involvement of neighboring structures. In our three cases described, 3D TEE provided additional understanding of spatial relationships between the dissection flap and neighboring structures such as the aortic valve and coronary orifices that were not fully appreciated with two-dimensional TEE, which affected surgical decisions in the operating room. This case series demonstrates the utility and benefit of real-time 3D TEE during intra-operative management of a type A aortic dissection.

Diagnosis and management of thoracic aortic dissection: An update

Acute thoracic aortic dissection is part of the acute aortic syndrome triad. Caused by an intimal tear in the lumen of the aorta, it leads to the creation and propagation of a false lumen. In the acute setting this can lead to malignant hypertension, pain and end organ malperfusion. In the chronic setting it can lead to aneurysm formation and rupture. It remains the most common aortic emergency, affecting up to 4 per 100000 people per year in the United Kingdom and United States. Despite advances in treatment and centralisation of vascular services, it continues to be associated with a high pre-admission and in-hospital mortality. Dissection is classified in several ways according to anatomical extent, timing and underlying pathology, all of which guides clinical management. Traditionally, medical management has been the mainstay of treatment in patients with uncomplicated disease. Surgery has been used in symptomatic patients. With published information now available from several prospective international registries, we are beginning to see the advantages of newer surgical treatment options such as endovascular repair, in the acute setting. This review provides an update on diagnosis and management of aortic dissection, including new information that has become available in recent years.

Type B Aortic Dissection: A Review of Prognostic Factors and Meta-analysis of Treatment Options

According to international guidelines, stable patients with uncomplicated Type B aortic dissection (TBAD) should receive optimal medical treatment. Despite adequate antihypertensive therapy, the long-term prognosis of these patients is characterized by a significant aortic aneurysm formation in 25-30% within four years, and survival rates from 50 to 80% at five years and 30 to 60% at 10 years. In a prospective randomized trial, preemptive thoracic endovascular aortic repair (TEVAR) in patients with chronic uncomplicated TBAD was associated with an excess early mortality (due to periprocedural hazards), but the procedure showed its benefit in prevention of aortic-specific mortality at five years of follow-up. However, preemptive TEVAR may not be the treatment of choice in all patients with uncomplicated TBAD because of the inherent periprocedural complications like stroke, paraparesis, and death, as well as stent graft-induced complications (i.e., retrograde dissection or endoleaks). Thus, the TEVAR-related deaths and complications (especially paraplegia and stroke) raise concerns that moderate the better survival with TEVAR at five years. By timely identification of those patients prone for developing complications, early intervention, preferably in the subacute or early chronic phase, may improve the overall long-term outcome for these patients. Therefore, early detectable and reliable prognostic factors for adverse events are essential to stratify patients who can be treated medically and those who will benefit from rigorous follow-up and, in the long-term, from timely, or even prophylactic, TEVAR. Several studies have identified prognostic factors in TBAD such as aortic diameter, partial false lumen thrombosis, false lumen thickness, and location of the primary entry tear. Combining these clinical and radiological predictors may be essential to implement a patient-specific approach designed to intervene only in those patients who are at high risk of developing complications to improve the long-term outcomes of patients with uncomplicated Type B aortic dissection.

THE IMPACT OF THE NUMBER OF TEARS IN PATIENT-SPECIFIC STANFORD TYPE B AORTIC DISSECTING ANEURYSM: CFD SIMULATION

It is believed that the progression of Stanford type B aortic dissection is closely associated with vascular geometry and hemodynamic parameters. The hemodynamic differences owing to the presence of greater than two tears have not been explored. The focus of the present study is to investigate the impact of an additional re-entry tear on the flow, pressure and wall shear stress distribution in the dissected aorta. A 3D aorta model with one entry and one re-entry tear was generated from computed tomography (CT) angiographic images of a patient with Stanford Type B aortic dissection. To investigate the hemodynamic effect of more than two tear locations, an additional circular re-entry tear was added 24 mm above the original re-entry tear. Our simulation results showed that the presence of an additional re-entry tear provided an extra return path for blood back to the true lumen during systole, and an extra outflow path into the false lumen during diastole. The presence of this additional path led to a decrease in the false lumen pressure, particularly at the distal region. Meanwhile, the presence of this additional tear causes no significant difference on the time average wall shear stress (TAWSS) distribution except at regions adjacent to re-entry tear 2. Moderate and concentrated TAWSS was observed at the bottom region of this additional tear which may lead to further extension of the tear distally.

A perspective review on numerical simulations of hemodynamics in aortic dissection

Aortic dissection, characterized by separation of the layers of the aortic wall, poses a significant challenge for clinicians. While type A aortic dissection patients are normally managed using surgical treatment, optimal treatment strategy for type B aortic dissection remains controversial and requires further evaluation. Although aortic diameter measured by CT angiography has been clinically used as a guideline to predict dilation in aortic dissection, hemodynamic parameters (e.g., pressure and wall shear stress), geometrical factors, and composition of the aorta wall are known to substantially affect disease progression. Due to the limitations of cardiac imaging modalities, numerical simulations have been widely used for the prediction of disease progression and therapeutic outcomes, by providing detailed insights into the hemodynamics. This paper presents a comprehensive review of the existing numerical models developed to investigate reasons behind tear initiation and progression, as well as the effectiveness of various treatment strategies, particularly the stent graft treatment.

Distal false lumen occlusion in aortic dissection with a homemade extra-large vascular plug: the candy-plug technique

PURPOSE

To report a technique to create an extra-large vascular plug for occlusion of a large distal false lumen in chronic aortic dissection.

TECHNIQUE

The "candy-plug" technique is demonstrated in a 58-year-old multimorbid man with a history of complicated acute type B aortic dissection and a 9-cm chronic thoracic false lumen aneurysm. The patient underwent a staged repair with a cervical debranching procedure as a first step and a thoracic endovascular aortic repair from the innominate artery to the celiac artery as a second step. To occlude the large false lumen from a distal route, a stent-graft was modified on-table with a diameter-restricting suture, giving it a wrapped candy-like shape. This plug was deployed into the false lumen, and the remaining opening was occluded with a standard vascular plug. On 3-month follow-up imaging, the thoracic false lumen aneurysm remained completely thrombosed.

CONCLUSION

The candy-plug technique can facilitate complete occlusion of chronic thoracic false lumen aneurysm by prohibiting distal false lumen backflow.

Conservative management of chronic aortic dissection with underlying aortic aneurysm

Aortic dissection is one of the most common aortic emergencies affecting around 2000 Americans each year. It usually presents in the acute state but in a small percentage of patients aortic dissections go unnoticed and these patients survive without any adequate therapy. With recent advances in medical care and diagnostic technologies, aortic dissection can be successfully managed through surgical or medical options, consequently increasing the related survival rate. However, little is known about the optimal long-term management of patients suffering from chronic aortic dissection. The purpose of the present report is to review aortic dissection, namely its pathology and the current diagnostic tools available, and to discuss the management options for chronic aortic dissection. We report a patient in which chronic aortic dissection presented with recurring episodes of vomiting and also discuss the management plan of our patient who had a chronic aortic dissection as well as an underlying aortic aneurysm.

Acute aortic emergencies--part 2: aortic dissections

Patients with aortic disease are some of the highest acuity patients that emergency clinicians encounter. Dissection is the most common aortic catastrophe and involves separation of the aortic layers in a longitudinal fashion leading to diminished perfusion and systemic ischemia. Characteristics of pain, branch vessel involvement, and incidence lead to an understanding of patient presentation, morbidity, and mortality. Diagnosis, selection of diagnostic studies, the degree of preoperative ischemia, and risk of operative mortality can be accomplished using validated clinical decision tools. Emergency interventions are guided by the type of dissection according to the Stanford classification system. Medical management includes pain control and anti-impulse, antihypertensive therapy through vasodilatation and blockage of the sympathetic β-response. The patient may then be evaluated for open surgical intervention, aortic fenestration, endovascularly placed stent grafts, or a combination possibly in a staged approach. Morbidity includes rupture, stroke, paraplegia, acute renal failure, bowel ischemia, and peripheral ischemia.

Case report and review of the literatureTotal Endovascular Repair of Acute Ascending Aortic Rupture

Thoracic aortic endografting has been successfully implemented to treat aneurysmal disease of the distal aortic arch and descending thoracic aorta. Although there are reports of ascending aortic endovascular interventions, the total endovascular repair of a ruptured ascending aorta secondary to a Type A dissection has not been described. We report the case of a 77-year-old patient who presented with a ruptured ascending aortic aneurysm secondary to degeneration of a Stanford type A aortic dissection. His surgical history was significant for orthotropic heart transplant 19 years prior. The dissection, aneurysm, and rupture occurred in the native aorta distal to the ascending aortic suture line. At presentation, he was hemodynamically unstable with a right hemothorax. We placed 3 Medtronic Talent Thoracic Stent Graft devices (Medtronic Inc, Minneapolis, MN) across the suture line in the ascending aorta, excluding the rupture. The patient survived and has been followed to 25 months.

Diseases of the thoracic aorta in women

Women have now equaled or surpassed men in the number of cardiovascular deaths per year in published statistics. In 2006, according to the National Center for Health Statistics and the Center for Disease Control, cardiovascular disease was the cause of death in 428,906 women (35% of all deaths in women) and in 394,840 men (33% of all deaths in men). Of those numbers, it was estimated that 5506 women (0.4% of all deaths in women) and 7732 men (0.6%) died because of aortic aneurysm or dissection. Currently, aortic disease ranks as the 19th leading cause of death with reported increases in incidence. Historically, aortic disease is thought to affect men more frequently than women with a varying reported gender ratio. Gender bias has long been implicated as an important factor, but often overlooked, in the analysis and interpretation of cardiovascular diseases outcome, in part, because of the under-representation of women in clinical trials and studies. In this section, we provide an up-to-date review of the epidemiology and management of common diseases of the thoracic aorta, focusing on the differences and similarities in women and men.

An experimental model of Stanford type B aortic dissection with intravenous epinephrine injection

The aim of this study was to create an experimental model of aortic dissection (AD) with a long-term patent false lumen to develop new treatments for Stanford type B aortic dissection. Sixteen adult beagle dogs (weight 14-18 kg) were used. After exposure and partially clamping, the descending aorta was cut through the adventitia to one-third of the depth of the tunica media. The aortic wall was divided into two layers by raspatory. Then half the circumference of the inner layer was cut transversely. All of the proximal layers and the distal outer layers were anastomosed together. Epinephrine was immediately used to expand the false lumen, and the effect was terminated using nitroglycerin when necessary. All dogs underwent both digital subtraction angiography (DSA) and computed tomography angiography (CTA) immediately after and 1 week and 1 month after surgery. The dogs were followed up at 1 day, 3 months, 1 year, and 2 years. The surgery was successful in 12 dogs. Dissection formation was observed immediately after epinephrine administration and confirmed by DSA and CTA. Our results showed typical characteristics of AD, such as a tear, septum, and true and false lumens. This is an easy and feasible way of developing a Stanford type B AD model by intravenous injection of epinephrine. In this canine model of AD, the false lumen has excellent long-term patency and the dissection plane is histologically similar to that in human AD. This model may contribute to the development of new treatments for Stanford type B AD.

Medical therapy of thoracic aortic aneurysms

Thoracic aortic aneurysm is a major health problem with multiple etiologies and potentially devastating consequences. Currently, no large randomized trial has shown that medical therapy can significantly slow or halt the progressive dilatation that eventually leads to dissection and rupture. A recent study that suggested that angiotensin receptor blocking agents slow the development of aneurysm dilatation in Marfan syndrome has revived interest in medical interventions to improve outcomes for patients with aortic aneurysm. In this article, we review the available data on established medical therapies and investigational medical therapies for thoracic aortic aneurysms.

Changes in inflammatory response after endovascular treatment for type B aortic dissection

This present study aims to investigate the changes in the inflammatory markers after elective endovascular treatment of Type B aortic dissection with aneurysm, as related to different anatomical features of the dissection flap in the paravisceral perfusion. Consecutive patients with type B aortic dissections with elective endovascular stent graft repair were recruited and categorized into different groups. Serial plasma levels of cytokines (Interleukin-1β, -6, -8, -10, TNF-α), chemokines (MCP-1), and serum creatinine were monitored at pre-, peri- and post-operative stages. The length of stent graft employed in each surgery was retrieved and correlated with the change of all studied biochemical parameters. A control group of aortic dissected patients with conventional medication management was recruited for comparing the baseline biochemical parameters. In total, 22 endovascular treated and 16 aortic dissected patients with surveillance were recruited. The endovascular treated patients had comparable baseline levels as the non-surgical patients. There was no immediate or thirty day-mortality, and none of the surgical patients developed post-operative mesenteric ischaemia or clinically significant renal impairment. All surgical patients had detectable pro-inflammatory mediators, but none of the them showed any statistical significant surge in the peri-operative period except IL-1β and IL-6. Similar results were obtained when categorized into different groups. IL-1β and IL-6 showed maximal levels within hours of the endovascular procedure (range, 3.93 to 27.3 higher than baseline; p = 0.001), but returned to baseline 1 day post-operatively. The change of IL-1β and IL-6 at the stent graft deployment was statistically greater in longer stent graft (p>0.05). No significant changes were observed in the serum creatinine levels. In conclusion, elective endovascular repair of type B aortic dissection associated with insignificant changes in inflammatory mediators and creatinine. All levels fell toward basal levels post-operatively suggesting that thoracic endovascular aortic repair is rather less aggressive with insignificant inflammatory modulation.

Complicated postpartum type B aortic dissection and endovascular repair

BACKGROUND

Fifty percent of aortic dissections in women younger than 40 years occur in association with pregnancy. Of these, half of type B dissections occur in the postpartum period.

CASE

A 30-year-old woman was status post spontaneous vaginal delivery at 30 weeks of gestation for fetal death, complicated by an eclamptic seizure. On postpartum day 4, she suffered an acute, complicated type B aortic dissection treated with endovascular stent graft placement.

CONCLUSION

Endovascular repair may be an attractive option for the treatment of complicated type B aortic dissections in pregnancy and the peripartum period, with reduced maternal and fetal mortality. This may allow the fetus to remain in situ and avoid the risks of surgery and possible cardiopulmonary bypass, with little radiation risk to the fetus.

Outcomes before and after initiation of an acute aortic treatment center

BACKGROUND

Acute aortic syndromes remain life-threatening. Time is of the essence, as mortality rises with increasing time after the acute episode. The aim of this report is to show changes in practice and outcomes after the establishment of an acute aortic treatment center (AATC) to expedite the care of acute aortic syndromes in a major metropolitan area with the belief that "door to intervention time under 90 minutes" reduces mortality and morbidity from acute aortic disease.

METHODS

A database of patients admitted with acute aortic disease (Type A and B aortic dissections, acute thoraco-abdominal aortic aneurysms, acute and ruptured abdominal aortic aneurysms) for 1 year prior to initiation (2007) and 1 year after initiation of the pathway (AATC) in 2008 was developed. Comorbidities were scored according to Society of Vascular Surgery criteria. Anatomic and functional outcomes were determined and categorized by Society of Vascular Surgery reporting criteria. Multivariate analysis was performed for categorical outcomes and Cox proportional hazard analyses for time-dependent outcomes.

RESULTS

Six hundred twenty-one patients reported with aortic disease to the cardiovascular services; 306 patients were considered to have acute disease. When compared with the year before the AATC was instituted, there was a 30% increase in the total number of admissions and a 25% increase in acute pathology after setting up the AATC (P = .02). There was a two-fold increase in thoracic aortic dissections admitted to the service. Initiation of the treatment pathway resulted in a highly significant 64% reduction in time to definitive therapy (526 ± 557 vs 187 ± 258 minutes, mean ± SD pre-AATC vs AATC; P = .0001). Comorbidity scores were equivalent between the two cohorts. Despite the increase in acuity, mortality (4% vs 6%) and morbidity (41% vs 45%) rates were unchanged, and there was a significant decrease in intensive care unit length of stay (5 vs 4 days, pre-AATC cohort vs the AATC cohort), but total hospital length of stay (11 vs 10 days) was unchanged. There was no correlation between deaths within 30 days and length of stay in the intensive care unit.

CONCLUSION

Establishment of a multidisciplinary AATC pathway was associated with a 30% increase in volume, 64% reduction in time to definitive treatment, improved throughput with reduced intensive care unit time, and maintained clinical efficacy despite an increase in acute admissions. These results suggest the concept be further evaluated.