Acute Uncomplicated Type B Aortic Dissection Research Articles (Page 1)

ObjectiveFalse lumen expansion is a major factor that determines long-term survival of uncomplicated type B aortic dissection (TBAD). The objective of this study was to investigate whether structural wall stress distributions computed from patient-specific acute TBAD geometries can be used to predict aortic growth rates.MethodsThree-dimensional (3D) computed tomography angiography (CTA) of 9 patients with acute uncomplicated TBAD were obtained at initial hospital admission and at their most recent follow-up visits. Patient-specific structural wall stress distributions were computed from the initial baseline CTA using a forward penalty method. Spatially varying blood pressure distributions, derived from computational fluid dynamics (CFD) simulations informed by patient-specific transthoracic echocardiography (TTE) and blood pressure (BP) measurements, were incorporated into the forward penalty stress analysis. Aortic growth rates were quantified and visualized within the 3D TBAD geometries using the initial baseline and follow-up scans. Linear mixed-effects regression analyses were performed to evaluate the spatial correlations between biomechanical markers (structural wall stress, wall shear stress, and pressure) and aortic growth rates.ResultsUtilizing initial baseline CTA, TTE, and BP data, the forward penalty analyses revealed hemodynamic and structural mechanics insights of acute uncomplicated TBADs. The linear mixed-effects model indicated that the fixed-effect association between structural wall stress and aortic growth rate distributions was statistically significant (p=0.039), which demonstrated that aortic segments experiencing high wall stress exhibited rapid growth. Fixed-effect associations were not significant when predicting growth rate using wall shear stress (p=0.86) or pressure (p=0.61) distributions. Significant Pearson correlation coefficients (p<0.05) were observed between structural wall stress and aortic growth rate in all patients.ConclusionHigh structural wall stress was associated with regions of high aortic growth rates, while false lumen thrombosis was associated with low wall stress. Structural wall stress derived from the forward penalty approach may be a novel predictor of aortic growth rate and failure of optimal medical therapy in acute TBAD.

Introduction: Thoracic endovascular aortic repair (TEVAR) has emerged as a promising treatment option for patients with type B aortic dissection (TBAD). However, there is a lack of evidence regarding the long-term morbidity of initial TEVAR compared to optimal medical therapy (OMT) in acute uncomplicated TBAD (uTBAD). Objective: To evaluate real-world data(RWD) on the long-term outcome of Japanese patients with acute uTBAD using a nationwide claims database. Methods: This retrospective cohort study utilizes JMDC, a nationwide claims database under Japan's universal healthcare system. We included patients who were initially hospitalized with a diagnosis of acute TBAD. We defined acute uTBAD by excluding those who died within one month, suffered aortic rupture, traumatic thoracic aortic injury, underwent open-chest surgery, experienced stroke or paralysis, or had less than six months of history in the JMDC. Patients who underwent TEVAR within three months of the index hospitalization (TEVAR group) were compared with those who received optimal medical therapy (OMT group). Propensity score (PS) matching was performed based on age, sex, and year of hospitalization. Using the Kaplan-Meier method, we calculated the cumulative rate of all-cause mortality and aorta-related events. Results: Of 18,445 patients diagnosed with aortic disease between January 2005 and December 2020, 641 were included in the study (OMT group: n=580, TEVAR group: n=61). After PS-matching, demographics of the groups (OMT_PSM: n=183 vs. TEVAR_PSM: n=61) were female (12.6% vs. 13.1%), median age (54 years [IQR, 48-60] vs. 54 years [IQR, 50-61]) and follow-up time (18 months [8-32] vs. 19 months [9-32]), respectively. Kaplan-Meier curves for the aortic-related events (Figure1, 2) are shown as long-term outcomes. Conclusions: This study successfully demonstrated that the estimated 5-year aortic-related event rate in acute uTBAD patients undergoing OMT is approximately 20%, demonstrating the relevance of the RWD source. However, the number of death events in the TEVAR and OMT groups was not sufficient to provide statistical power. Therefore, further studies are warranted to evaluate the long-term prognosis of initial TEVAR for uTBAD.

The treatment of acute type B aortic dissection (ATBAD) is currently a challenge for vascular surgeons, because of the early morbidity and mortality rates and the high risk of late aortic events up to 50% at 5 years. This study presents the initial outcomes of ATBAD treatment using optimal medical therapy alone or combined with proximal entry tear stent-graft coverage. Additionally, it provides an analysis of the evolution of the aortic diameter and its clinical consequences during the chronic phase in each group. Conducted as a retrospective, single-center study, we enrolled all consecutive ATBAD patients (n=130) treated between 2008 and 2020. The primary analysis studies the entire patient cohort based on their initial management approach, namely, medical treatment alone for uncomplicated ATBAD (n=67) or combined with stent-graft entry tear coverage (n=63). We also conducted a subgroup analysis to investigate factors associated with disease progression in the medical management group. Median follow-up was 29.5 months. During this time aneurysmal evolution was observed in: 42.4% of cases in the medical group compared with 21.8% in the stent-graft group, primarily affecting the thoracic aorta. The stent-graft group exhibited significant aortic remodeling, with a decrease in false lumen (FL) and thoracic aortic diameters. Initial aortic diameter ≥40 mm and FL ≥22 mm were independent risk factors for aneurysmal degeneration. Five-year survival was consistent at 76.1% in both groups. This study confirms the safety and efficacy of stent-graft entry tear coverage for ATBAD. Initial thoracic endovascular aortic repair (TEVAR) appears to reduce late aortic events by promoting aortic remodeling. Considering TEVAR's safety and potential to prevent late aortic complications, it may be considered for uncomplicated ATBAD patients with an initial aortic diameter ≥40 mm or an FL ≥22 mm. This study validates the efficacy and safety of using endovascular stent grafts to seal the proximal entry tear in cases of acute type B aortic dissections, compared to optimal medical therapy. Aortic remodelling significantly benefits from endovascular stent graft coverage of the proximal entry tear. Given the heightened risk of late aortic events observed in the medical therapy cohort, there appears to be a necessity for including endovascular interventions in the management of uncomplicated acute type B aortic dissections, particularly when aortic diameter is ≥40 mm and false lumen diameter is ≥22 mm.

BackgroundOptimal medical therapy (OMT) for uncomplicated type B aortic dissection (uTBAD) provides excellent short-term outcomes during follow up; however, its long-term therapeutic effectiveness is unsatisfactory. This study evaluated the predictive value of systemic immune-inflammation index (SII) for adverse events among patients with acute uTBAD undergoing OMT.MethodsWe performed a retrospective analysis of a prospectively maintained database between 2013 and 2020. The primary end point in this study was composite outcomes including aortic intervention, all-cause mortality, retrograde type A aortic dissection (rTAAD) and aortic diameter growth > 5 mm. The patients were divided into high and low SII groups according to the optimal cut-off value of SII as determined using the receiver operating characteristic curve. Cox proportional hazards models were constructed to estimate the hazards ratios and identify the predictors of composite outcomes.ResultsA total of 124 patients with acute uTBAD who underwent OMT were enrolled. One patient died during hospitalisation. At the end of a mean follow-up duration of 51 ± 23 months, 53 (43.1%) patients experienced composite outcomes, 15 patients (12.2%) died, 31 (25.2%) underwent aortic intervention, 21 (17.1%) exhibited diameter growth of > 5 mm, and 2 developed rTAAD. The patients were divided into low SII group (n = 78, 62.9%) and high SII group (n = 46, 37.1%) as per the optimal cut-off SII value of 1449. The incidence of composite outcomes in high SII group was significantly higher than that in low SII (28 [60.9%] vs. 26[33.3%], p < 0.01). Patients with high SII demonstrated significantly higher mortality rate than those with a low SII (11 [23.9%] vs. 5 [6.4%], respectively; p < 0.01). In addition, the high SII group had significantly higher rate of aortic-related reinterventions than the low SII group (16 [34.8%] vs. 15 [19.2%], p = 0.03). Multivariable Cox analyses showed that a high SII score was independently associated with composite outcomes rate (hazard ratio, 2.15; 95% confidence interval, 1.22–3.78; p < 0.01).ConclusionsThe long-term therapeutic effectiveness of OMT alone in patients with acute uTBAD is unsatisfactory. An SII > 1449 at the time of diagnosis is an independent predictor of OMT failure.

IntroductionIn acute type B aortic dissection (TBAD) patients, thoracic endovascular aorta repair (TEVAR) and best medical treatment (BMT) have both been employed for the clinical management of this condition. The relative efficacy of TEVAR and BMT when used to manage cases of acute uncomplicated TBAD, however, remains to be clarified.AimTo conduct a pooled meta-analysis comparing acute uncomplicated TBAD patient outcomes associated with primary TEVAR or BMT treatment.Material and methodsRelevant articles published up to July 2023 were identified by searching the Web of Science, PubMed, and Wanfang databases. Pooled analyses of endpoints from these studies were then conducted.ResultsSix relevant studies were included in this meta-analysis, involving 522 and 535 patients who underwent TEVAR and BMT treatment, respectively. No significant differences were observed between these two groups with respect to pooled hospitalization duration, re-intervention rates, early mortality, organ failure incidence, stroke incidence, or the incidence of retrograde type A dissection (p = 0.89, 0.12, 0.09, 0.36, 0.09, and 0.95, respectively). TEVAR, however, was associated with significantly better pooled thrombosed/obliterated false lumen, late mortality, aorta-related mortality, and rupture rates relative to BMT (p = 0.00001, 0.002, 0.0001, and 0.04, respectively). TEVAR was associated with a 7% pooled type I endoleak incidence rate. Endpoints exhibiting significant heterogeneity included hospitalization duration, thrombosed/obliterated false lumen rates, and rupture rates (I2 = 96%, 73%, and 61%, respectively).ConclusionsWhile TEVAR and BMT yield similar short-term outcomes for acute uncomplicated TBAD patients, TEVAR may be associated with a better long-term patient prognosis.

Aortic dissection is a life-threatening condition caused by a tear in the tunica intima which creates a false lumen into the aortic wall. Acute type B aortic dissection (TBAD) is defined by the presence of the entry tear in the aorta distal to the left subclavian artery, without ascending aorta and arch involvement, and accounts for 25-40% of all aortic dissections. Optimal medical therapy (OMT), focused on blood pressure and heart rate control, remains the gold standard treatment, especially for patients with uncomplicated TBAD, while complicated dissections require surgical therapy. Recent studies have shown that a considerable number of patients treated only with OMT develop late aorta-related complications that increase morbidity and mortality, as well as the need for surgical intervention. During the last decades, emerging evidence indicates that thoracic endovascular aortic repair (TEVAR) is safe and effective in the treatment of TBAD, both complicated and uncomplicated, with improved long-term survival outcomes and aortic remodeling in combination with OMT compared to OMT alone. However, in cases of acute uncomplicated TBAD the optimal timing for TEVAR is not entirely clarified and there is lack of long-term evidence. Therefore, the role of pre-emptive TEVAR for these patients is still uncertain and the management of acute uncomplicated TBAD remains challenging.

Postoperative acute kidney injury after thoracic endovascular aortic repair for acute type B aortic dissection

Readmission after early thoracic endovascular aortic repair versus medical management of acute type B aortic dissection

Introduction: Treatment of acute type B aortic dissection (ATBAD) has evolved with the use of endovascular technology. This study evaluates the short and long-term outcomes of patients with ATBAD over a 15-year period. Methods: A retrospective review identified patients with ATBAD at our institution between 2006 and 2020. Patients were analyzed based on presentation status (complicated vs. uncomplicated) and treatment. Complicated ATBAD (cATBAD) included malperfusion of any vascular bed, intractable pain, rupture, or rapid expansion. Postoperative outcomes were evaluated within the initial 30 days after diagnosis when managed medically or within thirty days of surgical intervention. Descriptive statistics was performed to assess short-term outcomes. Kaplan-Meier survival was performed to assess long-term mortality. Results: A total of 296 patients presented with ATBAD in the study period. Out of those, 121 patients presented with cATBAD, while 175 patients presented with uncomplicated ATBAD (uATBAD). Out of the cATBAD group, 89 were treated with TEVAR, and 32 were treated with medication only. The cATBAD group was younger than the uCTBAD group (62.0 vs. 65.2, p=0.05). Early mortality was more common in cATBAD than uATBAD (9.9% vs 2.3%, p=0.013). When comparing cATBAD who underwent TEVAR vs conservative medical management, early mortality was higher in the medication only group (12.5% vs 9.0% p = 0.013). Permanent paraplegia occurred in 1.1% (1/89)of patients undergoing TEVAR. Kaplan-Meier survival analysis demonstrated no significant difference in long-term mortality between the cATBAD and uATBAD groups (Logrank p = 0.23). Among the uATBAD patients, 10.3% (18/175) required future intervention for type B dissection (12 TEVAR, 6 open). Among the TEVAR patients, 20.2% (18/89) required re-operations (11 endovascular repairs, 7 open). Conclusions: ATBAD is associated with significant morbidity and mortality, especially in the setting of a complicated presentation. While uATBAD is associated with better short-term outcomes, the diminishing difference in long-term outcome between cATBAD and uATBAD calls for reevaluation of our indications for intervention and may suggest that the remodeling associated with TEVAR could have long term benefit.

Introduction: Currently, Type B aortic dissection (TBAD) without the presence of either organ malperfusion or aortic rupture is managed with optimal medical therapy (OMT) consisting of an aggressive anti-hypertensive medical regimen and surveillance imaging. Although OMT achieves excellent early survival, the long-term outcomes with OMT alone remain poor. In this study, we identified anatomic shape features that correlate with OMT failure and aortic growth rates in uncomplicated TBAD via statistical shape modeling (SSM). Methods: Contrast CT scans of patients with acute uncomplicated TBAD were analyzed from 25 patients who were initially treated with OMT. OMT failure was defined as aortic intervention (surgical or endovascular repair, n = 8). Statistical shape models were constructed using principal component analysis (PCA) and partial least square regression (PLSR) to extract anatomic shape features from the aorta and flap geometries. For 14 of the 25 patients, additional follow-up CT scans (5 to 117 months) were used to quantify the rate of aortic expansion. Results: Four PCA (feature 5: p = 0.048, 12: p = 0.005, 14: p = 0.047, 24: p = 0.038) and two PLSR (feature 1: p = 0.000, 2: p = 0.004) shape features were effective at separating OMT failure patients and patients who were adequately treated with OMT. Two PCA features were moderately correlated with aortic growth rate (correlation coefficient, feature 11; r = 0.579, 21: r = 0.503). A PLSR feature was correlated with the growth rate (r = 0.867). Representative shape features are shown in Figure 1. Conclusions: Anatomic shape features extracted from SSM were correlated with the outcomes of OMT and aortic growth rate. SSM shape features may provide additional anatomic risk factors in addition to aortic diameter that predicts aneurysmal degeneration and the need for surgical intervention. Future investigations will incorporate the SSM shape features to determine the risk of OMT failure in uncomplicated TBAD patients.

Objective This study was to evaluate the clinical efficacy of thoracic endovascular aortic repair (TEVAR) combined with Best Medical Therapy (BMT) in acute uncomplicated type B aortic dissection (TBAD). Methods Using the random method, 90 patients admitted to our hospital between January 2018 and January 2020 with acute uncomplicated TBAD were randomly divided into a control group and a study group, with 45 cases in each of the groups. The effectiveness of BMT combined with TEVAR treatment was compared. Results The incidence of recent adverse reactions did not differ significantly between the two groups. Compared to the control group, the 1-year survival rate and 2-year survival rate of patients in the study group were considerably higher. In order to examine the relationship between survival and time, the Kaplan-Meier curve was used. Both groups reached the median survival time after 24 months of follow-up. The expected survival time of the study group was longer than that of the control group. False lumen thrombosis or absence of thrombus was significantly more prevalent in the study group than in the control group. Conclusion For patients with acute uncomplicated TBAD, BMT combined with TEVAR can significantly improve the long-term survival rate and increase the expected survival time.

OBJECTIVESThe aim of this study was to evaluate changes in aortic growth rate and factors influencing aneurysmal dilatation after uncomplicated acute type B aortic dissection (ABAD).METHODSMedically treated patients with uncomplicated ABAD between September 2004 and January 2020 were retrospectively reviewed. Diameters of 6 different sites in the descending aorta were measured and aortic growth rate was calculated according to the time interval. Factors associated with aneurysmal changes were also investigated.RESULTSThis study enrolled a total of 105 patients who underwent >2 serial computed tomography with a mean follow-up duration of 35.4 (12.1–77.4) months. The mean overall growth rates of the proximal descending thoracic aorta (DTA), mid-DTA, distal DTA, proximal abdominal aorta, maximal DTA and maximal abdominal aorta were 0.6 (1.9), 2.9 (5.2), 2.1 (4.0), 1.2 (2.2), 3.3 (5.6) and 1.4 (2.5) mm/year, respectively. The growth rate was higher at the early stage. It decreased over time. Growth rates of proximal DTA, mid-DTA, distal DTA, proximal abdominal aorta, maximal DTA, and maximal abdominal aorta within 3 months after dissection were 1.3 (9.6), 12.6 (18.2), 7.6 (11.7), 5.9 (7.5), 16.7 (19.8) and 6.8 (8.9) mm/year, respectively. More than 2 years later, they were 0.2 (0.6), 1.6 (1.6), 1.2 (1.3), 0.9 (1.4), 1.7 (1.9) and 1.2 (1.7) mm/year, respectively. Factors associated with aneurysmal changes after uncomplicated ABAD included an elliptical true lumen (odds ratio = 3.16; 95% confidence interval: 1.19–8.41; P = 0.021) and a proximal entry >10 mm (odds ratio = 3.08; 95% confidence interval: 1.09–8.69; P = 0.034) on initial computed tomography imaging.CONCLUSIONSThe aortic growth rate was higher immediately after uncomplicated ABAD but declined eventually. Patients with an elliptical true lumen and a large proximal entry might be good candidates for early endovascular intervention after uncomplicated ABAD.

BackgroundMedical therapy is the standard treatment for uncomplicated acute type B aortic dissection (ATBAD), but there is little evidence of the need for intensive care unit (ICU) management. Therefore, we aimed to investigate the effects of ICU treatment on uncomplicated ATBAD.MethodsWe retrospectively studied patients with uncomplicated ATBAD who were medically treated between January 2010 and July 2020. Patients were divided into short-term ICU stay (SIS) and long-term ICU stay (LIS) groups, according to a 48-hour cutoff of ICU stay duration. The incidence of pneumonia and delirium, rate of aortic events, hospital mortality, and survival rate were compared.ResultsFifty-five patients were treated for uncomplicated ATBAD (n=29 for SIS and n=26 for LIS). The incidence of pneumonia (3.6% vs. 7.7%) and delirium (14.3% vs. 34.6%) was higher in the LIS group than in the SIS group, but the differences were not statistically significant. The survival rates at 1, 3, and 5 years were not different between the two groups (SIS: 96.4%, 92.2%, and 75.5% vs. LIS: 96.2%, 88.0%, and 54.2%, respectively; p=0.102). Multivariate Cox regression analysis for aortic events showed that using a calcium channel blocker lowered the risk of aortic events.ConclusionLong-term ICU treatment is unlikely to be necessary for the treatment of uncomplicated ATBAD. Active use of antihypertensive agents, such as calcium channel blockers, may be needed during the follow-up period.

Effect of Timing of Thoracic Endovascular Aneurysm Repair After Type B Aortic Dissection in the Society for Vascular Surgery Vascular Quality Initiative Postapproval Project for Dissection

Timing of endovascular repair impacts long-term outcomes of uncomplicated acute type B aortic dissection

Early Thoracic Endovascular Aortic Repair is Superior to Medical Therapy in Acute Uncomplicated Type B Aortic Dissection

Early Thoracic Endovascular Aortic Repair Is Superior to Medical Therapy for Acute Uncomplicated Type B Aortic Dissection

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. 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. 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). 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.

A monolithic, fully coupled fluid-structure interaction (FSI) computational framework was developed to account for dissection flap motion in acute type B aortic dissection (TBAD). Analysis of results included wall deformation, pressure, flow, wall shear stress (WSS), von Mises stress and comparison of hemodynamics between rigid wall and FSI models. Our FSI model mimicked realistic wall deformation that resulted in maximum compression of the distal true lumen (TL) by 21.4%. The substantial movement of intimal flap mostly affected flow conditions in the false lumen (FL). Flap motion facilitated more flow entering the FL at peak systole, with the TL to FL flow split changing from 88:12 in the rigid model to 83:17 in the FSI model. There was more disturbed flow in the FL during systole (5.8% FSI vs 5.2% rigid) and diastole (13.5% FSI vs 9.8% rigid), via a λ2 -criterion. The flap-induced disturbed flow near the tears in the FSI model caused an increase of local WSS by up to 70.0% during diastole. This resulted in a significant reduction in the size of low time-averaged WSS (TAWSS) regions in the FL (113.11 cm2 FSI vs 177.44 cm2 rigid). Moreover, the FSI model predicted lower systolic pressure, higher diastolic pressure, and hence lower pulse pressure. Our results provided new insights into the possible impact of flap motion on flow in aortic dissections, which are particularly important when evaluating hemodynamics of acute TBAD. NOVELTY STATEMENT: Our monolithic fully coupled FSI computational framework is able to reproduce experimentally measured range of flap deformation in aortic dissection, thereby providing novel insights into the influence of physiological flap motion on the flow and pressure distributions. The drastic flap movement increases the flow resistance in the true lumen and causes more disturbed flow in the false lumen, as visualized through the λ2 criterion. The flap-induced luminal pressure is dampened, thereby affecting pressure measures, which may serve as potential prognostic indicators for late complications in acute uncomplicated TBAD patients.

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