Aortic Dissection Research in China: Analysis of Studies Funded by the National Natural Science Foundation of China.

OBJECTIVE: The National Natural Science Foundation of China (NSFC) has made great progress in promoting the development of aortic dissection research in recent years. This study aimed to examine the development and research status of aortic dissection research in China so as to provide references for future research. METHODS: The NSFC projects data from 2008 to 2019 were collected from the Internet-based Science Information System and other websites utilized as search engines. The publications and citations were retrieved by Google Scholar, and the impact factors were checked by the InCite Journal Citation Reports database. The investigator's degree and department were identified from the institutional faculty profiles. RESULTS: A total of 250 grant funds totaling 124.3 million Yuan and resulting in 747 publications were analyzed. The funds in economically developed and densely populated areas were more than those in underdeveloped and sparsely populated areas. There was no significant difference in the amount of funding per grant between different departments' investigators. However, the funding output ratios of the grants for cardiologists were higher than those for basic science investigators. The amount of funding for clinical researchers and basic scientific researchers in aortic dissection was also similar. Clinical researchers were better in terms of the funding output ratio. CONCLUSION: These results suggest that the medical and scientific research level of aortic dissection in China has been greatly improved. However, there are still some problems that urgently need to be solved, such as the unreasonable regional allocation of medical and scientific research resources, and the slow transition from basic science to clinical practice.

Trends in the incidence, surgical management and outcomes of type B aortic dissections in Australia over the last decade.

OBJECTIVES: This study aims to investigate the incidence and in-hospital outcomes of surgical repair for type B aortic dissection (TBAD) in Australia. METHODS: Data were obtained from the Australasian Vascular Audit (AVA) and the Australian Institute of Health and Welfare (AIHW). The former is a total practice audit mandated for all members of the Australian and New Zealand Society for Vascular Surgery (ANZSVS) while the latter is an independent government agency which records all healthcare data in Australia. All cases of TBAD which underwent surgical intervention (endovascular or open repair) between 2010 and 2019 were identified using prospectively recorded data from the AVA (New Zealand data was excluded). The primary outcomes were temporal trends in procedures and hospital mortality; secondary outcomes were complications and risk factors for mortality. All admissions and procedures for, and hospital deaths from, TBAD in Australia were identified in AIHW datasets using the relevant diagnosis and procedure codes, with age-standardized rates calculated for the period 2000-01 to 2018-19. RESULTS: A total of 567 cases of TBAD underwent vascular surgical intervention (AVA data, Australia). Of these, 96.3% were treated by endovascular repair. There was an increase in the annual procedure number from 45 in 2010 to 88 in 2019. In-hospital mortality was 4.8% for endovascular repair and 19% for open repair (p = 0.021). From 2000-01 to 201819, the age-standardized procedure rates for TBAD (Australia) doubled, the proportion of admitted patients undergoing a procedure rose from 28% to 43%, and in-hospital deaths fell by 25%. CONCLUSION: There has been an increasing incidence of vascular surgical intervention for TBAD in Australia. The majority of patients received endovascular therapy while the mortality from surgically managed TBAD appears to be falling.

The relationship between quality of life and health promotion behavior in patients with type B aortic dissection: a cross-sectional study.

BACKGROUND: To understand the current situation of health promotion behavior and quality of life among aortic dissection survivors and the correlation between them. METHODS: Sociodemographic characteristics were collected. T-test and variance analysis were applied for univariate analysis. Quality of life was measured using the SF-36 Questionnaire, and health-promoting behaviors were measured using the aortic dissection health promotion behavior questionnaire. The association between type B aortic dissection survivors' health promotion behavior and health status questionnaire (SF-36) scores was determined through Pearson's correlation coefficients. This association was analyzed through multivariable regression analysis. RESULTS: A total of 131 type B aortic dissection survivors were evaluated through the self-developed aortic dissection patient health promotion behavior scale and health status questionnaire (SF-36). Results showed that the health promotion behavior of Stanford B aortic dissection survivors (85.05 ± 11.28) correlated with their Mental Component Summary (MCS) (55.23 ± 30.72; r = 0.359, P < 0.01). The model showed 39.00% variance shared between behavior motivation and MCS (R2 = 0.390, F = 13.189, P < 0.01). CONCLUSION: Type B aortic dissection survivors in Zunyi, China had a lower quality of life. Medical staff can formulate intervention measures from behavioral motivation to improve the quality of life of aortic dissection survivors.

4D-Flow Cardiac Magnetic Resonance Imaging in Chronic Aortic Dissection Assessment: A Powerful Qualiquantitative Diagnostic Tool.

4-dimensional-flow cardiac magnetic resonance in patients with aortic dissection in chronic/post repair phase as a complementary diagnostic tool for anatomic-functional evaluation. Quali-quantitative analysis of 3 patients with this pathology clearly showing the true/false lumen, quantitative flow in false lumen, and helping in discerning lumen origin from different arterial vessels. (Level of Difficulty: Advanced.).

False Lumen Flow Assessment by Magnetic Resonance Imaging and Long-Term Outcomes in Uncomplicated Aortic Dissection.

BACKGROUND: Despite the absence of clinical complications after an acute aortic dissection (AD) with persistent patent false lumen (FL), a high risk for clinical events may persist. OBJECTIVES: The aim of this study was to assess the natural evolution of noncomplicated AD and ascertain whether different FL flow patterns by magnetic resonance imaging (MRI) have independent prognostic value for AD-related events beyond established morphologic parameters. METHODS: One hundred thirty-one consecutive patients, 78 with surgically treated type A dissections and 53 with medically treated type B dissections, were followed up prospectively after acute AD with persistent patent FL in the descending aorta. Maximum aortic diameter, true lumen compression, entry tear, and partial FL thrombosis by computed tomography were assessed. Systolic antegrade true lumen and FL flow volumes and diastolic antegrade and retrograde flows were analyzed by MRI during the first year after AD. RESULTS: After a median follow-up period of 8.0 years (IQR: 4.6-10.9 years), 43 patients presented aorta-related events (25 died and 18 required endovascular treatment). FL systolic antegrade flow ≥30% with respect to total systolic antegrade flow and retrograde diastolic flow ≥80% with respect to total diastolic FL flow were predictors of aortic events. In multivariate analysis, aortic diameter >45 mm (HR: 2.91), type B dissection (HR: 2.44), and MRI flow pattern (HR: 16.87) were independent predictors of AD-related events. CONCLUSIONS: High systolic antegrade flow volume in the FL with significant diastolic retrograde flow assessed by MRI and aortic diameter >45 mm identify patients with higher risk for complications in whom more aggressive management would be indicated.

Kinking of Frozen Elephant Trunk Hybrid Prostheses: Incidence, Mechanism, and Management.

Introduction: Kinking of the Frozen Elephant Trunk (FET) stent graft is one of the most devastating complications of the FET procedure. It can present post-operatively with reduced arterial pressures in the lower limbs and intermittent claudication. However, it can also be visualized intra-operatively by the surgeons. Unresolved kinking of the stent graft can result in intraluminal thrombus formation and subsequent multi-organ septic emboli. Aims: The main scope of this review is to collate, summarize and present all the evidence in the literature on kinking of FET stent grafts. Methods: We carried out a comprehensive literature search on multiple electronic databases including PubMed, EMBASE, Ovid, and Scopus to collate all research evidence on the incidence, mechanism, and management of FET graft kinking. Results: Incidence of kinking is variable, ranging from 0% to 8% in the literature, with varying rates associated with each stent graft type. The Thoraflex HybridTM prosthesis seemed to be the most commonly used and superior graft, and out of all the 15 cases of kinking reported in the literature, 5 (33.3%) were associated with just the Frozenix graft which had the highest incidence. There are multiple theories regarding the mechanism of kinking, including the direction of blood flow, the length of the stent grafts used, and the position of the prosthesis in relation to the flexure of the aorta. Multiple reparative management techniques have been suggested in the literature and include total endovascular repair, open repair, balloon dilatation, and deploying a second stent graft. Conclusion: Graft kinking is one of the most critical complications of the FET technique. Its life-threatening sequelae warrant appropriate follow-up of these patients post-operatively, in addition to time management if kinking is suspected. Given the limited evidence in the literature, future studies should incorporate graft kinking into their outcomes reporting.

How point-of-care Ultrasound became an essential part of the assessment in the Emergency Department.

From its first use in medicine, ultrasonography has been an excellent non-invasive diagnostic tool. The use of ultrasound increased dramatically especially in the last decade, as it is a painless, safe, and widely accessible, especially with the development of pocket ultrasound machines. In addition, it is crucial in promptly diagnosing unstable patients in emergency settings. Currently, emergency physicians are leaning more towards ultrasound, fellowships and university courses are created around the globe to teach this essential skill. This article highlights the importance of ultrasound in the hands of emergency physicians while presenting a life-threatening diagnosis that could have been easily missed if it wasn't for the use of ultrasound. Cases like these are frequently seen in the emergency departments, and it is when blinded by a tunnel vision, and anchoring bias, that these serious diagnoses can be left undiagnosed. Many individuals in the medical community are against the use of ultrasound by untrained physicians, but it remains highly recommended that emergency physicians get a proper training on the use of this tool for it is of great value in the emergency department.

An in vitro Assessment of the Haemodynamic Features Occurring Within the True and False Lumens Separated by a Dissection Flap for a Patient-Specific Type B Aortic Dissection.

One of the highest mortality rates of cardiovascular diseases is aortic dissections with challenging treatment options. Currently, less study has been conducted in developing in vitro patient-specific Type B aortic dissection models, which mimic physiological flow conditions along the true and false lumens separated by a dissection flap with multiple entry and exit tears. A patient-specific Stanford Type B aortic dissection scan was replicated by an in-house manufactured automatic injection moulding system and a novel modelling technique for creating the ascending aorta, aortic arch, and descending aorta incorporating arterial branching, the true/false lumens, and dissection flap with entry and exit intimal tears. The physiological flowrates and pressure values were monitored, which identified jet stream fluid flows entering and exiting the dissection tears. Pressure in the aorta's true lumen region was controlled at 125/85 mmHg for systolic and diastolic values. Pressure values were obtained in eight sections along the false lumen using a pressure transducer. The true lumen systolic pressure varied from 122 to 128 mmHg along the length. Flow patterns were monitored by ultrasound along 12 sections. Detailed images obtained from the ultrasound transducer probe showed varied flow patterns with one or multiple jet steam vortices along the aorta model. The dissection flap movement was assessed at four sections of the patient-specific aorta model. The displacement values of the flap varied from 0.5 to 3 mm along the model. This model provides a unique insight into aortic dissection flow patterns and pressure distributions. This dissection phantom model can be used to assess various treatment options based on the surgical, endovascular, or hybrid techniques.

The impact of hospital size on national trends and outcomes in isolated open proximal aortic surgery.

OBJECTIVE: To determine the impact of hospital size on national trend estimates of isolated open proximal aortic surgery for benchmarking hospital performance. METHODS: Patients age >18 years who underwent isolated open proximal aortic surgery for aneurysm and dissection from 2002 to 2014 were identified using the National Inpatient Sample. Concomitant valvular, vessel revascularization, re-do procedures, endovascular, and surgery for descending and thoracoabdominal aorta were excluded. Discharges were stratified by hospital size and analyzed using trend, multivariable regression, propensity-score matching analysis. RESULTS: Over a 13-year period, 53,657 isolated open proximal aortic operations were performed nationally. Although the total number of operations/year increased (∼2.9%/year increase) and overall in-hospital mortality decreased (∼4%/year; both P < .001 for trend), these did not differ by hospital size (P > .05). Large hospitals treated more sicker and older patients but had shorter length of stay and lower hospital costs (both P < .001). Even after propensity-score matching, large hospital continued to demonstrate superior in-hospital outcomes, although only statistically for major in-hospital cardiac complications compared with non-large hospitals. In our subgroup analysis of dissection versus non-dissection cohort, in-hospital mortality trends decreased only in the non-dissection cohort (P < .01) versus dissection cohort (P = .39), driven primarily by the impact of large hospitals (P < .01). CONCLUSIONS: This study demonstrates increasing volume and improving outcomes of isolated open proximal aortic surgeries nationally over the last decade regardless of hospital bed size. Moreover, the resource allocation of sicker patients to larger hospital resulted shorter length of stay and hospital costs, while maintaining similar operative mortality to small- and medium-sized hospitals.

Computed Tomography Angiography Assessment of Acute Aortic Syndromes: Classification, Differentiating Imaging Features, and Imaging Interpretation Pitfalls.

An acute aortic syndrome (AAS) is an important life-threatening condition that requires early detection and management. Acute intramural hematoma (IMH), aortic dissection (AD) and penetrating atherosclerotic ulcer (PAU) are included in AAS. ADs can be classified using the well-known Stanford or DeBakey classification systems. However, these classification systems omit description of arch dissections, anatomic variants, and morphologic features that impact outcome. The Society for Vascular Surgery and Society of Thoracic Surgeons (SVS-STS) have recently introduced a classification system that classifies ADs according to the location of the entry tear (primary intimomedial tear, PIT) and the proximal and distal extent of involvement, but does not include description of all morphologic features that may have diagnostic and prognostic significance. This review describes these classification systems for ADs and other AAS entities as well as their limitations. Typical computed tomography angiography (CTA) imaging appearance and differentiating features of ADs, limited intimal tears (LITs), IMHs, intramural blood pools (IBPs), ulcer-like projections (ULPs), and PAUs will be discussed. Furthermore, this review highlights common imaging interpretation pitfalls, what should be included in a comprehensive CTA report, and provides a brief overview of current management options.

Ethnic Disparities in CT Aortography Use for Diagnosing Acute Aortic Syndrome.

Purpose: To determine whether CT aortography was performed in proportion to patient risk for acute aortic syndrome (AAS) and incidence of AAS for different ethnic groups. Materials and Methods: All atraumatic thoracic aorta CT aortographic examinations performed in adults (age > 15 years) suspected of having AAS between January 2009 and December 2019 at Auckland City Hospital (New Zealand) were included. Patients were risk stratified using the aortic dissection detection risk score (ADD-RS). The primary outcomes were the ratio of CT aortography rates to rates of positive CT aortographic examinations and the incidence of AAS. Population census data were used to determine age-standardized incidence of AAS in the emergency department (ED). Results: In total, 1646 CT aortographic examinations were performed in 1543 patients (mean age, 62 years ± 16 [SD]; 877 male patients). Maori (34% [68 of 203]) and Pacific Islanders (35% [80 of 229]) were more likely to be at high risk of AAS (ADD-RS > 1) compared with patients from other ethnic groups (25% [308 of 1214]); in the ED catchment population, age-standardized AAS incidence was significantly higher in Maori (6.9 per 100 000 person-years [95% CI: 4.3, 10.4]) and Pacific Islanders (5.3 [95% CI: 3.4, 7.8]) than in other ethnic groups (2.3 [95% CI: 1.8, 2.8]). Despite this higher incidence, disproportionately fewer CT aortographic examinations were requested in the ED for Maori (9.2 CT aortographic examinations per AAS diagnosis) and Pacific Islanders (9.2 CT aortographic examinations per AAS diagnosis) compared with other ethnic groups (13.8 CT aortographic examinations per AAS diagnosis). Conclusion: Maori and Pacific Islanders were at disproportionately higher risk of AAS but had fewer requested CT aortographic examinations compared with other ethnic groups. This increased risk of AAS in Pacific Islander and indigenous Maori patients should be considered by clinicians when investigating AAS.Keywords: Ethnicity, Maori, Pacific Islander, Aortic Dissection Detection Risk Score, Acute Aortic Syndrome, Aortic Dissection, CT Angiography Supplemental material is available for this article. © RSNA, 2022.

Computational Fluid Dynamic Technique for Assessment of How Changing Character of Blood Flow and Different Value of Hct Influence Blood Hemodynamic in Dissected Aorta.

Using computer tomography angiography (CTA) and computational structural analysis, we present a non-invasive method of mass flow rate/velocity and wall stress analysis in type B aortic dissection. Three-dimensional (3D) computer models of the aorta were calculated using pre-operative (baseline) and post-operative CT data from 12 male patients (aged from 51 to 64 years) who were treated for acute type B dissection. A computational fluid dynamics (CFD) technique was used to quantify the displacement forces acting on the aortic wall in the areas of endografts placement. The mass flow rate and wall stress were measured and quantified using the CFD technique. The CFD model indicated the places with a lower value of blood velocity and shear rate, which corelated with higher blood viscosity and a probability of thrombus appearance. Moreover, with the increase in Hct, blood viscosity also increased, while the intensity of blood flow provoked changing viscosity values in these areas. Furthermore, the velocity gradient near the tear surface caused high wall WSS; this could lead to a decreased resistance in the aorta's wall with further implications to a patient.

The potential value of the neutrophil to lymphocyte ratio for early differential diagnosis and prognosis assessment in patients with aortic dissection.

OBJECTIVES: The aim of the study was to assess the diagnostic performance and clinical utility of the neutrophil to lymphocyte ratio (NLR) in patients with suspected aortic dissection (AD) and investigate its role in predicting in-hospital mortality in AD. METHODS: NLR values were calculated and compared in 467 consecutive patients with initially suspected AD. A receiver operating characteristic (ROC) curve analysis with the area under the curve (AUC) was used to evaluate the discriminative accuracy and predictive capability of the NLR for AD. Clinical utility was determined by decision curve analysis (DCA). The association between NLR and in-hospital mortality was investigated by logistic regression analyses in patients diagnosed with AD. RESULTS: The NLR was significantly elevated in patients with AD, and the optimal cut-off point for the NLR to distinguish AD from other acute chest pain diseases was 5.67 [AUC (95% CI): 0.877 (0.844-0.905)]. We recommended an NLR of 2.43 as the appropriate cut-off point with 96.9% sensitivity and a negative likelihood ratio (LR) of 0.09 to satisfy clinical requirements for diagnosis. DCA showed that the use of NLR had a positive net benefit. The deceased patients with AD had a higher NLR than the discharged patients. Moreover, the NLR was an independent predictor of in-hospital mortality for AD [adjusted odds ratio (OR): 1.084 (1.029-1.142)], and patients with higher NLR values tended to have a higher risk of in-hospital mortality. The optimal cut-off point for the NLR to predict in-hospital mortality was 9.20 [AUC (95% CI): 0.695 (0.619-0.765)]. CONCLUSIONS: As an easily available and inexpensive parameter, the NLR could serve as a valuable clinical biomarker for early differential diagnosis and prognosis assessment of AD.

Wall Shear Stress Assessment of the False Lumen in Acute Type B Aortic Dissection Visualized by 4-Dimensional Flow Magnetic Resonance Imaging: An Ex-Vivo Study.

BACKGROUND: Four-dimensional flow magnetic resonance imaging (4D flow MRI) can accurately visualize and quantify flow and provide hemodynamic information such as wall shear stress (WSS). This imaging technique can be used to obtain more insight in the hemodynamic changes during cardiac cycle in the true and false lumen of uncomplicated acute Type B Aortic Dissection (TBAD). Gaining more insight of these forces in the false lumen in uncomplicated TBAD during optimal medical treatment, might result in prediction of adverse outcomes. METHODS: A porcine aorta dissection model with an artificial dissection was positioned in a validated ex-vivo circulatory system with physiological pulsatile flow. 4D flow MR images with 3 set heartrates (HR; 60 bpm, 80 bpm and 100 bpm) were acquired. False lumen volume per cycle (FLV), mean and peak systolic WSS were determined from 4D flow MRI data. For validation, the experiment was repeated with a second porcine aorta dissection model. RESULTS: During both experiments an increase in FLV (initial experiment: ΔFLV = 2.05 ml, p < 0.001, repeated experiment: ΔFLV = 1.08 ml, p = 0.005) and peak WSS (initial experiment: ΔWSS = 1.2 Pa, p = 0.004, repeated experiment: ΔWSS = 1.79 Pa, p = 0.016) was observed when HR increased from 60 to 80 bpm. Raising the HR from 80 to 100 bpm, no significant increase in FLV (p = 0.073, p = 0.139) was seen during both experiments. The false lumen mean WSS increased significant during initial (2.71 to 3.85 Pa; p = 0.013) and non-significant during repeated experiment (3.22 to 4.00 Pa; p = 0.320). CONCLUSION: 4D flow MRI provides insight into hemodynamic dimensions including WSS. Our ex-vivo experiments showed that an increase in HR from 60 to 80 bpm resulted in a significant increase of FLV and WSS of the false lumen. We suggest that strict heart rate control is of major importance to reduce the mean and peak WSS in uncomplicated acute TBAD. Because of the limitations of an ex-vivo study, 4D flow MRI will have to be performed in clinical setting to determine whether this imaging model would be of value to predict the course of uncomplicated TBAD.

Assessment of Liver Function for Evaluation of Short- and Long-Term Outcomes in Type B Aortic Dissection Patients Undergoing Thoracic Endovascular Aortic Repair.

Background and Aims: Patients with decreased liver function suffer from poor outcomes when undergoing procedures. We aimed to explore the impact of liver fibrosis identified by aspartate transaminase-to-platelet ratio index (APRI) and poor liver functional reserve assessed by a model of end-stage liver disease (MELD) and albumin-bilirubin(ALBI) score on the prognosis of patients with type B aortic dissection (TBAD) undergoing thoracic endovascular aortic repair (TEVAR). Methods: A retrospective analysis of a prospectively maintained database from 2010 to 2017 was performed. APRI > 0.5 was used to identify those with significant liver fibrosis. Logistic and Cox regression analyses were performed to investigate the association between liver fibrosis, MELD, and ALBI with adverse events. Results: TEVAR was performed on 812 TBAD patients including 35 with liver fibrosis and 777 without. Twenty-four (3.0%) patients deceased during hospitalization and 69 (8.8%) patients died after a median 48.2 months follow-up. Multivariable analysis revealed that liver fibrosis, MELD, and ALBI were independently associated with in-hospital [fibrosis: odds ratio (OR) 23.73, 95% confidence interval (CI) 8.89-63.33, P < 0.001; MELD: OR 1.08, 95% CI 1.03-1.14, P = 0.003; ALBI: OR 4.45; 95% CI 1.56-12.67, P = 0.005] and follow-up mortality [fibrosis: hazard ratio (HR) 4.69, 95% CI 1.93-11.42, P = 0.001; MELD: HR 1.07, 95% CI 1.04-1.10, P < 0.001; ALBI: HR 2.88, 95% CI 1.53-5.43, P = 0.001]. The association was further corroborated by a subgroup analysis. Conclusion: Liver fibrosis and poor liver functional reserve could significantly increase the morbidity and mortality after TEVAR. APRI, MELD, and ALBI should be calculated and routinely used for preoperative risk stratification. Strict preoperative preparation and elaborate postoperative care are necessary to improve these patients' prognosis.

Barriers and facilitators affecting implementation of the Canadian clinical practice guidelines for the diagnosis of acute aortic syndrome.

BACKGROUND: Acute aortic syndrome (AAS) is an uncommon, life-threatening emergency that is frequently misdiagnosed. The 2020 Canadian clinical practice guidelines for the diagnosis of AAS incorporate all available evidence into four key recommendations. In order to facilitate the implementation of these recommendations, a clinical decision aid was created. The objective of this study was to identify barriers and facilitators among physicians prior to implementation of the guideline recommendations in a multicentre step wedge cluster randomized control trial. METHODS: We conducted semi-structured interviews with nine emergency room physicians working at five sites distributed between urban academic and rural settings. We used purposive sampling, contacting physicians until data saturation was reached. Interview questions were designed to understand potential barriers and facilitators to guideline recommendation uptake and use. Responses were analysed according to the Theoretical Domains Framework, and overarching themes describing these barriers and facilitators were identified. RESULTS: Two themes and six subthemes encompassing 13 theoretical domains were identified. These included clinical decision-making support, awareness of the evidence, social factors, expected consequences, ability of physicians to acquire the necessary data and ease of use. A majority of interviewees anticipated that the guideline recommendations would support clinical decision making and more effectively risk-stratify patients. Other facilitators included endorsement of the guidelines by professional organizations and peers. Barriers to implementation include the fact that laboratory testing and knowledge of the rationale for its use in the investigation of AAS were not widespread. The complexity of the clinical decision aid and concerns about test specificity were also identified as potential barriers to use. CONCLUSION: Physicians were amenable to using the AAS guideline recommendations to support clinical decision-making and to reduce resource use. A structured intervention should be developed to address the identified barriers and leverage the facilitators in order to ensure successful implementation. Our findings may have implications for the implementation of other guidelines used in emergency departments.

Hospitalization Cost and In-hospital Outcomes Following Type B Thoracic Aortic Dissection Repair.

BACKGROUND: Several studies have reported lower mortality and morbidity after thoracic endovascular aortic repair (TEVAR) when compared to open surgical repair (OSR) in the treatment of type B aortic dissection (TbAD). However, there are few studies in the literature on the cost of both treatment options. Thus, the aim of this study is to focus on in-hospital outcomes and cost associated with TbAD repair procedures in a national database in the United States. METHODS: A retrospective review of the Premier Healthcare Database (PHD) between June 2009 and March 2015 was performed. ICD-9-CM codes were used to identify patients who underwent OSR or TEVAR for TbAD. Endpoints included in-hospital adverse events, in-hospital mortality and hospitalization cost. Logistic regression models and generalized linear models were used to assess the impact of treatment type on the main outcomes. RESULTS: Out of 1752 patients with TbAD, 54.3% underwent OSR and 45.7% underwent TEVAR. Patients in the TEVAR group were older [median age, 64 (IQR 54-73) vs. 59 (IQR 49-70), P < 1] and more likely to have preexisting comorbidities. IAE rates were 78.6% for the OSR group compared to 43.1% for the TEVAR group, P < 0.001. Patients in the OSR group showed significantly higher in-hospital mortality (15.3% vs. 5.9%, P < 0.001). After adjusting for potential confounders, OSR was associated with a 5-fold increase in IAE [aOR(95%CI): 4.8 (3.8-6.1), P < 0.001] and a 3-fold increase in in-hospital mortality [aOR(95%CI): 3.3 (2.1-5.1), P < 0.001]. In regards to charges related to the hospital stay, total cost was significantly higher among patients undergoing OSR $53,371 ($39,029-$80,471) vs. TEVAR $45,311 ($31,479-$67,960), P < 0.001. CONCLUSION: The present study shows that TEVAR presents an advantage in terms of morbidity, mortality and cost when compared to OSR in the treatment of TbAD. However, long-term cost-effectiveness of both procedures remains unknown. Further research is warranted to see whether the superiority of TEVAR is maintained over time.

Outcomes and risk management in type B aortic dissection patients with acute kidney injury: a concise review.

PURPOSE: Type B aortic dissection is a rare but life-threatening disease. Thoracic endovascular aortic repair (TEVAR) was widely used for Type B aortic dissection patients in the last decade due to the lower mortality and morbidity compared with open chest surgical repair (OCSR). AKI in type B aortic dissection is a well-recognized complication and indicates poor short-term and long-term outcome. The objective of this concise review was to identify the risk factors and the impact of AKI on type B aortic dissection patients. METHODS AND RESULTS: A literature search was performed using PubMed, Embase, MEDLINE, and Cochrane Library with the search terms 'type B aortic dissection' and 'acute kidney injury' (AKI), and all English-language literatures published in print or available online from inception through August 2020 were thoroughly reviewed. Studies that reported relative AKI risks and outcomes in type B aortic dissection patient were included. Major mechanisms of AKI in type B aortic dissection included renal hypoperfusion, inflammation response, and the use of contrast medium. Type B aortic dissection patients with AKI significantly had increased hospital stay duration, need of renal replacement therapy, and 30-d and 1-year mortality. CONCLUSIONS: AKI in type B aortic dissection is a well-recognized complication and associated with poor short-term and long-term outcome. Early identification of high-risk patients, early diagnosis of AKI, stabilization of the hemodynamic parameters, avoidance of nephrotoxic drugs, and optimization of the use of contrast agents are the major strategies for the reduction of AKI in type B aortic dissection patients.

Aortic dissection assessment by 4D phase-contrast MRI with hemodynamic parameters: the impact of stent type.

BACKGROUND: To explore the diagnostic performance of 4-dimensional phase-contrast magnetic resonance imaging (4D PC-MRI) in evaluating aortic dissection in different clinical scenarios. METHODS: The study group comprised 32 patients with a known aortic dissection who each underwent computed tomography angiography (CTA), and then 4D PC-MRI with a 1.5-T MR scanner. The 4D PC-MRI images were compared with the CTA images to evaluate the aortic size, branch identification, and iliac and femoral arterial access. RESULTS: The patients were divided into three groups: (I) patients diagnosed with Type B aortic dissection but did not undergo intervention (n=8); (II) patients with residual aortic dissection after open repair of Type A dissection (n=7); (III) patients who underwent endovascular aortic repair with or without open surgery (n=17). Without radiation or contrast media injection, 4D PC-MRI provided similar aortic images for patients in Group 1 and most of those in Group 2. In Group 3, stainless steel stents affected image quality in three patients. High-quality 4D PC-MRI images were obtained for the remaining 14 patients in Group 3, who had non-stainless steel stents, and provided major aortic information comparable to that provided by CTA with contrast media. The hemodynamic parameters of true and false lumens were evaluated between three patients with Type B aortic dissections and three patients who underwent thoracic endovascular aortic repair for their aortic dissection. The stroke volume was higher in the true lumen of the patients with stent-grafts than in the patients with Type B aortic dissection without intervention. The regurgitant fraction, an indicator of nonlaminar flow, was higher in the false lumens than in the true lumens. All 32 patients in this study tolerated 4D PC-MRI without adverse events. CONCLUSIONS: 4D PC-MRI is radiation- and contrast media-free option for imaging aortic dissection. It not only provided images comparable in quality to those obtained with CTA but also provided information on hemodynamic parameters, including endoleak detection after thoracic endovascular aortic repair. 4D PC-MRI was safe and accurate in evaluating chronic Type B aortic dissection and residual aortic dissection after surgery for acute Type A aortic dissection. Therefore, it could be a potential tool in treating pathology in aortic dissection, especially for patients with malperfusion syndrome of visceral vessels and in young patients with renal function impairment. However, certain endograft materials, especially stainless steel, may prevent the further application of 4D PC-MRI and should be avoided.