Comparison of mid-term outcomes of endovascular repair and medical management in patients with acute uncomplicated type B aortic dissection

Acute Type B Aortic Dissection: Insights From a Single-Center Retrospective Experience Over 12 Years

INTRODUCTION

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.

CLINICAL IMPACT

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.

Efficacy of intentional undersized thoracic endovascular repair for Stanford type B aortic dissection

OBJECTIVE

Thoracic endovascular aneurysm repair (TEVAR) is widely used for the treatment of aortic dissection. Endograft oversizing is a risk factor for stent graft-induced new entry tears and retrograde type A aortic dissection. However, there is no clear consensus on the optimal graft size selection for Stanford type B acute or subacute aortic dissection (TBAD). Herein, we examined the safety and efficacy of TEVAR using an intentionally undersized endograft to treat TBAD.

METHODS

This retrospective chart review study included 82 patients who underwent TEVAR for acute or subacute Stanford TBAD between 2015 and 2022. We measured the true lumen diameter just distal to the subclavian artery and opted for a stent graft of the same diameter. In instances where deformation resulting from false lumen pressure displacement was pronounced, we measured the diameter at the site just proximal to the subclavian artery. Patients' characteristics, procedural, in-hospital, and follow-up data, and aortic remodeling were analyzed. The aortic diameter was analyzed using one-way analysis of variance followed by Dunnett's test. Survival and freedom from reintervention were estimated using Kaplan-Meier curves.

RESULTS

The follow-up rate was 98.4%. The mean age was 58.3 ± 12.3 years, and 76 were men (92.7%). The mean diameters of the stent graft and native proximal landing zone were 30.9 ± 3.2 mm and 30.8 ± 3.0 mm, respectively. The oversize rate of the stent graft in relation to the native proximal aortic diameter was 0.3% ± 4.7%. In-hospital mortality was observed in one patient, retrograde type A aortic dissection in one patient, distal stent graft-induced new entry tear in zero patients, and type 1a endoleak in 22 patients (26.8%). Type 1a endoleaks, characterized by antegrade false lumen blood flow originating from the primary entry, in 12 patients spontaneously disappeared within 1 year of follow-up. According to aortic remodeling, 59 patients (86.8%) achieved complete aortic remodeling at the aortic arch level and 51 (75.0%) at the eighth thoracic vertebral level. The diameters of the aortic arch and descending aorta were significantly reduced compared with the postoperative measurements (P <.001). Survival rates were 97.5% and 93.6% at 1 and 3 years, respectively. Freedom from reintervention was 84.7% and 84.7% at 1 and 3 years, respectively.

CONCLUSIONS

Intentionally undersized TEVAR was safe and achieved acceptable aortic remodeling despite a high rate of type 1a endoleaks. A type 1a endoleak was acceptable as it primarily diminished during the mid-term follow-up.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL IMPACT

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

False lumen regurgitation fraction and energy loss in the aorta measured using four-dimensional flow MRI to predict expansion of acute uncomplicated type B aortic dissection: a prospective study

AIM

To assess the relationship between four-dimensional (4D)-flow-derived false lumen regurgitation fraction (FLRF) and energy loss (EL) percentage in the descending thoracic aorta (DTA) with the aortic growth rate in uncomplicated type B aortic dissection (uTBAD).

METHODS AND MATERIALS

In this prospective study performed on 15 patients with uTBAD, computed tomography (CT) angiography and 4D-flow magnetic resonance imaging (MRI) were performed at the initial presentation with follow-up CT at 2 years. 4D-flow parameters, including maximum peak systolic velocity (PSV), FLRF, and percentage of EL were measured using Circle CV42. The significance of these parameters for expansion (>3 mm/year) of aortic dissection was analysed.

RESULTS

Five patients had an enlarging aorta, while 10 had a stable aortic size. The Mann-Whitney U-test showed entry tear >10 mm (p=0.026), FLRF (7.6 ± 8.9 versus 64.8 ± 16.7%; p=0.002), EL in the DTA in (1.61 ± 1.99 versus 2.21 ± 0.32 μW/cm3; p=0.014) and percentage of EL in the DTA to overall energy loss from the ascending aorta to the DTA (37 ± 15% versus 66 ± 17%; p=0.005), having a statistically significant different expanding stable dissection. A positive significant Spearman correlation was noted with the aortic growth rate (in millimetres over 2 years) with FLRF (r=0.71, p=0.003), EL in the DTA (r=0.56, p=0.007), and percentage of EL in the DTA (r=0.62, p=0.003).

CONCLUSION

4D flow parameters, including FLRF and the percentage amount of EL in the DTA may help predict aortic growth at an early stage in uTBAD.

Midterm Outcomes of Endovascular vs. Medical Therapy for Uncomplicated Type B Aortic Dissection: Meta-Analysis of Reconstructed Time to Event Data

OBJECTIVE

To evaluate outcomes of thoracic endovascular aortic repair (TEVAR) vs. medical therapy in uncomplicated type B aortic dissections (TBAD).

DATA SOURCES

PubMed/MEDLINE, EMBASE, SciELO, LILACS, CENTRAL/CCTR, Google Scholar, and reference lists of relevant articles.

REVIEW METHODS

This was a pooled meta-analysis of time to event data extracted from studies published by December 2022 for the following outcomes: all cause mortality, aortic related mortality, and late aortic interventions. Certainty of evidence was evaluated through the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool.

RESULTS

Ten studies met the eligibility criteria (eight observational; two randomised trials), comprising 17 906 patients (2 332 patients in the TEVAR groups and 15 574 patients in the medical therapy group). Compared with patients who received medical therapy, patients who underwent TEVAR had a statistically significantly lower risk of all cause death (HR 0.79, 95% CI 0.72 - 0.87, p < .001; GRADE certainty: low) and lower risk of aortic related death (HR 0.43, 95% CI 0.30 - 0.62, p < .001; GRADE certainty: low) without statistically significant difference in the risk of late aortic interventions (HR 1.05, 95% CI 0.88 - 1.26, p = .56; GRADE certainty: low). In the subgroup analyses, TEVAR was associated with lower risk of all cause death when randomised controlled trials only were pooled (HR 0.44, 95% CI 0.23 - 0.83, p = .012; GRADE certainty: moderate), younger patients only (HR 0.56, 95% CI 0.47 - 0.67, p < .001; GRADE certainty: low), Western populations only (HR 0.85, 95% CI 0.77 - 0.93, p = .001; GRADE certainty: low) and non-Western populations only (HR 0.47, 95% CI 0.35 - 0.62, p < .001; GRADE certainty: low). For all cause mortality and aortic related mortality, restricted mean survival time was overall 396 days and 398 days longer with TEVAR (p < .001), respectively, which means that TEVAR was associated with lifetime gain.

CONCLUSION

TEVAR may be associated with better midterm survival and lower risk of aortic related death in the follow up of patients treated for uncomplicated TBAD compared with medical therapy; however, randomised controlled trials with larger sample sizes and longer follow up are still warranted.

Population risk profile analysis of acute uncomplicated type B aortic dissection patients undergoing thoracic endovascular aortic repair

BACKGROUND

Uncomplicated type B aortic dissection (unTBAD) comprises the estimated majority of type B aortic dissection (TBAD), presenting without any of the complications associated with complicated TBAD (coTBAD). Although first-line treatment for coTBAD is thoracic endovascular aortic repair (TEVAR), and despite the fact that TEVAR has proven its safety and effectiveness in the treatment of unTBAD, unTBAD is still being predominantly managed conservatively with medical therapy, with a small proportion of patients being offered TEVAR.

AIMS

The main scope of this review is to highlight the evidence in the literature of the demographic characteristics and associated co-morbidities of unTBAD patients undergoing TEVAR in order to produce a risk stratification system to achieve favourable outcomes.

METHODS

A comprehensive literature search was conducted using multiple electronic databases including PubMed, Ovid, Scopus, and EMBASE.

RESULTS

Multiple demographic characteristics and associated co-morbidities of unTBAD patients affecting TEVAR outcomes were identified, assessed, and investigated, including age, gender, race, genetics, medical conditions, such as hypertension and diabetes, and lifestyle factors such as smoking. Most factors were associated with increased risks of mortality and morbidity, while others, such as race, were identified as being protective against those when it comes to TEVAR.

CONCLUSION

Despite the favourable results yielded by TEVAR in unTBAD, there remains a grey area concerning its management. Thus, it is important to incorporate the demographics and co-morbidities of unTBAD patients' when into clinical judgement when assessing indications for TEVAR intervention to ensure optimum results can be achieved.

Reintervention after Thoracic Endovascular Aortic Repair of Uncomplicated Type B Aortic Dissection

BACKGROUND

Data are scarce regarding the incidence, reasons, potential risk factors, and long-term outcomes of reintervention after thoracic endovascular aortic repair (TEVAR) in patients with uncomplicated type B aortic dissection (TBAD).

METHODS

Between January 2010 and December 2020, 238 patients with uncomplicated TBAD who received TEVAR were analyzed retrospectively. The clinical baseline data, aorta anatomy, dissection characteristics, and details of the TEVAR procedure were evaluated and compared. A competing-risk regression model was used to estimate the cumulative incidences of reintervention. The multivariate Cox model was used to identify the independent risk factors.

RESULTS

The mean follow-up time was 68.6 months. A total of 27 (11.3%) cases of reintervention were observed. The competing-risk analyses showed that the 1-, 3-, and 5-year cumulative incidences of reintervention were 5.07%, 7.08%, and 14.0%, respectively. Reasons for reintervention included endoleak (25.9%), aneurysmal dilation (22.2%), retrograde type A aortic dissection (18.5%), distal stent-graft-induced new entry and false lumen expansion (18.5%), and dissection progression and/or malperfusion (14.8%). Multivariable Cox analysis demonstrated that a larger initial maximal aortic diameter (Hazard ratio [HR], 1.75; 95% Confidence interval [CI], 1.13-2.69, p = 0.011) and increased proximal landing zone oversizing (HR, 1.07; 95% CI, 1.01-1.47, p = 0.033) were the significant risk factors for reintervention. Long-term survival rates were comparable between patients with or without reintervention (p = 0.915).

CONCLUSIONS

Reintervention after TEVAR in patients with uncomplicated TBAD is not uncommon. A larger initial maximal aortic diameter and excessive proximal landing zone oversizing are associated with the second intervention. Reintervention does not significantly affect long-term survival.

Risk factors for distal stent graft-induced new entry after endovascular repair in uncomplicated type B aortic dissection

OBJECTIVE

We investigated the risk factors for distal stent graft-induced new entry (dSINE) after thoracic endovascular aortic repair for patients with uncomplicated type B aortic dissection (TBAD) and reported the outcomes of using a tapered stent graft and dSINE reintervention.

METHODS

A total of 226 patients with uncomplicated TBAD who had undergone thoracic endovascular aortic repair between January 2010 and December 2018 were analyzed retrospectively. The global features of the thoracic aorta and the local features of the proximal and distal landing zones were evaluated and compared between the dSINE and non-dSINE groups. A multivariate Cox model was used to identify the independent risk factors for dSINE. The cumulative incidence of reintervention was estimated using competing risk models.

RESULTS

After a median follow-up of 4.6 years, 16 patients (7.1%) had developed dSINE. Multivariable Cox regression analysis demonstrated that a type III aortic arch, decreased angle, increased distal oversizing, and increased distal mismatch ratio were significant risk factors for dSINE. Of the patients with tapered stent grafts, five with a ≤4-mm taper had developed dSINE. However, no dSINE was seen in the >4-mm taper group (P = .024). Reintervention was performed for 7 of the 16 patients with dSINE (43.8%). The mean time from the initial detection of dSINE to reintervention was 6.43 ± 4.62 months. The competing risk analyses showed that the cumulative incidence of reintervention in the dSINE group at 1, 3, and 5 years was 25.0%, 37.5%, and 43.5%, respectively.

CONCLUSIONS

A type III aortic arch, excessive distal oversizing and mismatch ratio, and severe angulation were associated with dSINE in patients with uncomplicated TBAD. The use of a tapered stent graft with a >4-mm taper could help prevent dSINE in patients with a high taper ratio. Aggressive reintervention was associated with favorable long-term outcomes for patients with progressive dSINE.

Initial Thoracic Endovascular Aortic Repair vs Medical Therapy for Acute Uncomplicated Type B Aortic Dissection

Importance

Thoracic endovascular aortic repair (TEVAR) has increasingly been used for uncomplicated type B aortic dissection (uTBAD) despite limited supporting data.

Objective

To assess whether initial TEVAR following uTBAD is associated with reduced mortality or morbidity compared with medical therapy alone.

Design, Setting, and Participants

This cohort study included Centers for Medicare & Medicaid Services inpatient claims data for adults aged 65 years or older with index admissions for acute uTBAD from January 1, 2011, to December 31, 2018, with follow-up available through December 31, 2019.

Exposures

Initial TEVAR was defined as TEVAR within 30 days of admission for acute uTBAD.

Main Outcomes and Measures

Outcomes included all-cause mortality, cardiovascular hospitalizations, aorta-related and repeated aorta-related hospitalizations, and aortic interventions associated with initial TEVAR vs medical therapy. Propensity score inverse probability weighting was used.

Results

Of 7105 patients with eligible index admissions for acute uTBAD, 1140 (16.0%) underwent initial TEVAR (623 [54.6%] female; median age, 74 years [IQR, 68-80 years]) and 5965 (84.0%) did not undergo TEVAR (3344 [56.1%] female; median age, 76 years [IQR, 69-83 years]). Receipt of TEVAR was associated with region (vs South; Midwest: adjusted odds ratio [aOR], 0.66 [95% CI, 0.53-0.81]; P < .001; Northeast: aOR, 0.63 [95% CI, 0.50-0.79]; P < .001), Medicaid dual eligibility (aOR, 0.76; 95% CI, 0.63-0.91; P = .003), hypertension (aOR, 1.26; 95% CI, 1.03-1.54; P = .03), peripheral vascular disease (aOR, 1.24; 95% CI, 1.02-1.49; P = .03), and year of admission (2012, 2013, 2014, and 2015 were associated with greater odds of TEVAR compared with 2011). After inverse probability weighting, mortality was similar for the 2 strategies up to 5 years (hazard ratio [HR], 0.95; 95% CI, 0.85-1.06), as were aorta-related hospitalizations (HR, 1.12; 95% CI, 0.99-1.27), aortic interventions (HR, 1.01; 95% CI, 0.84-1.20), and cardiovascular hospitalizations (HR, 1.05; 95% CI, 0.93-1.20). In a sensitivity analysis that included deaths within the first 30 days, initial TEVAR was associated with lower mortality over a period of 1 year (adjusted HR [aHR], 0.86; 95% CI, 0.75-0.99; P = .03), 2 years (aHR, 0.85; 95% CI, 0.75-0.96; P = .008), and 5 years (aHR, 0.87; 95% CI, 0.80-0.96; P = .004).

Conclusions and Relevance

In this study, 16.0% of patients underwent initial TEVAR within 30 days of uTBAD, and receipt of initial TEVAR was associated with hypertension, peripheral vascular disease, region, Medicaid dual eligibility, and year of admission. Initial TEVAR was not associated with improved mortality or reduced hospitalizations or aortic interventions over a period of 5 years, but in a sensitivity analysis that included deaths within the first 30 days, initial TEVAR was associated with lower mortality. These findings, along with cost-effectiveness and quality of life, should be assessed in a prospective trial in the US population.

Peripheral Eosinophil Count Is Associated With the Prognosis of Patients With Type B Aortic Dissection Undergoing Endovascular Aortic Repair: A Retrospective Cohort Study

Background Eosinophil count (EOS) has been proposed to provide prognostic information in multiple cardiovascular disorders. However, few researchers have investigated the predictive value of EOS for patients with type B aortic dissection who had thoracic endovascular repair. Methods and Results The authors reviewed the records of 912 patients with type B aortic dissection who were treated with thoracic endovascular repair in Changhai Hospital, Shanghai. By using receiver operating characteristic curve analysis, patients were divided into 2 groups based on the admission EOS cutoff value (<7.4×10⁶/L [n=505] and ≥7.4×10⁶/L [n=407]). To reduce selection bias, propensity score matching was applied. Multivariable regression analysis and Kaplan-Meier curves were performed to assess the association between EOS and long-term outcomes. Furthermore, we investigated nonlinear correlations between EOS and outcomes using general additive models with restricted cubic splines. In the matched population, lower EOS was associated with significantly higher 30-day mortality (4.1% vs 0%, P=0.007). There was no statistically difference in 30-day adverse events between the 2 groups (all P>0.05). Kaplan-Meier analysis revealed that patients with an EOS <7.4×10⁶/L had a higher incidence of 1-year all-cause death (7.95% vs. 2.34%, P=0.008) and aortic-related death (5.98% vs 1.81%, P=0.023) than those with higher EOS. Multivariable Cox analysis showed that continuous EOS was independently associated with 1-year mortality (hazard ratio, 3.23 [95% CI, 1.20-8.33], P=0.019). In addition, we discovered a nonlinear association between EOS and 1-year outcomes. Conclusions Lower admission EOS values predict higher short- and long-term mortality after thoracic endovascular repair.

Cost analysis of thoracic endovascular aortic repair in type B aortic dissection: How much does quality cost?

BACKGROUND

Aortic dissection (AD) is a life-threatening medical emergency that affects an estimated 3-4 people per 100,000 annually, with 40% of cases classified as type B AD (TBAD). TBAD can be further classified as being complicated (co-TBAD) or uncomplicated (un-TBAD) based on the presence or absence of certain features such as malperfusion and rupture. TBAD can be managed conservatively with optimal medical therapy (OMT), or invasively with open surgical repair (OSR) or thoracic endovascular aortic repair (TEVAR), depending on several factors such as type of TBAD and its clinical acuity. The cost-effectiveness, or cost-benefit profile, of these strategies must be given equal consideration. However, TBAD studies featuring cost analyses are limited within the literature. This narrative review aims to address the gap in the literature on cost-effectiveness of TBAD treatments by providing an overview of cost analyses comparing OMT with TEVAR in un-TBAD and TEVAR with OSR in co-TBAD. Another aim is to provide a market analysis of the commercially available TEVAR devices.

METHODS

A comprehensive literature search was performed using several search engines including PubMed, Ovid, Google Scholar, Scopus, and Embase to identify and extract relevant studies.

RESULTS

Several TEVAR devices are available commercially on the global market costing $12,000-19,495. Nevertheless, the Terumo Aortic RELAY® stent graft seems to be the most cost-effective, yielding highly favourable clinical outcomes. Despite the higher initial cost of TEVAR, evidence in the literature strongly suggest that it is superior to OMT for un-TBAD on the long-term. In addition, TEVAR is well established in the literature as being gold-standard repair technique for co-TBAD, replacing OSR by offering a more optimal cost-benefit profile through lower costs and improved results.

CONCLUSIONS

The introduction of TEVAR has revolutionized the field of aortovascular surgery by offering a highly efficacious and long-term cost-effective treatment for TBAD.

Endovascular Repair of the Thoracic Aorta Combined with Drug Therapy in Acute Uncomplicated Type B Aortic Dissection

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.

Risk profile analysis of uncomplicated type B aortic dissection patients undergoing thoracic endovascular aortic repair: Laboratory and radiographic predictors

BACKGROUND

There is emerging evidence to support pre-emptive thoracic endovascular aortic repair (TEVAR) intervention for uncomplicated type B aortic dissection (unTBAD). Pre-emptive intervention would be particularly beneficial in patients that have a higher baseline risk of progressing to complicated TBAD (coTBAD). There remain debate on the optimal clinical, laboratory, morphological, and radiological parameters, which would identify the highest-risk patients that would benefit most from pre-emptive TEVAR.

AIM

This review summarizes evidence on the clinical, laboratory, and morphological parameters that increase the risk profiles of unTBAD patients.

METHODS

A comprehensive literature search was carried out on multiple electronic databases including PubMed, EMBASE, Ovid, and Scopus to collate all research evidence on the clinical, laboratory, and morphological parameters that increase the risk profiles of unTBAD patients RESULTS: At present, there are no clear clinical guidelines using risk-stratification to inform the selection of unTBAD patients for TEVAR. However, there are noticeable literature trends that can assist with the identification of the most at-risk unTBAD patients. Patients are at particular risk when they have refractory pain and/or hypertension, elevated C-reactive protein (CRP), larger aortic diameter, and larger entry tears. These risks should be considered alongside factors that increase the procedural risk of TEVAR to create a well-balanced approach. Advances in biomarkers and imaging are likely to identify more pertinent parameters in the future to optimize the development of balanced, risk-stratified treatment protocols.

CONCLUSION

There are a variety of risk profiling parameters that can be used to identify the high-risk unTBAD patient, with novel biomarkers and imaging parameters emerging. Longer-term evidence verifying these parameters would be ideal. Further randomized controlled trials and multicentre registry analyses are also warranted to guide risk-stratified selection protocols.

Acute or Subacute, the Optimal Timing for Uncomplicated Type B Aortic Dissection: A Systematic Review and Meta-Analysis

Objective

To evaluate the optimal timing (acute or subacute) of thoracic endovascular aortic repair (TEVAR) for uncomplicated B aortic dissection (uTBAD) through a systematic review and meta-analysis.

Method

A comprehensive literature search was undertaken across three major databases (EMBASE/Medline, PubMed, and Cochrane Library) and was assessed until November 2021 to identify studies reporting the outcomes of TEVAR utilized to treat patients with uTBAD. The continuous variables were compared between the two groups using t-test and the categorical variables were compared using the χ2-test. A meta-analysis was used to produce pooled odds ratios for early and follow-up outcomes. The random effects models were applied. A statistical analysis was performed using R software v.4.1.

Result

A comprehensive literature search found 490 citations published within the predetermined time span of the analysis. Three studies including 1,193 patients (acute group 718, subacute group 475) were finally included for downstream meta-analysis. An acute uTBAD group presented with higher rates both in 30-day complications (20.5 vs. 13.7%; p = 0.014) and mortality (4.6 vs. 1.3%; p = 0.004) than subacute group. The respiratory complications were significantly higher in the acute group than in the subacute group (10.8 vs. 5.0%; p = 0.015). The procedure success rate (90.8 vs. 93.6%; p = 0.329), the follow-up mortality (7.7 vs. 7.6%; p = 1) and dissection-related late mortality (3.9 vs. 5.3%; p = 0.603) showed no significant difference.

Conclusion

Our meta-analysis suggested that despite significantly higher 30-day complications and 30-day mortality in the acute uTBAD group, there was no significant difference in the follow-up mortality between the two groups.

Systematic Review Registration

PROSPERO, identifier: CRD42021247609.

Systematic review and meta-analysis of current evidences in endograft therapy versus medical treatment for uncomplicated type B aortic dissection

OBJECTIVE

Best medical therapy (BMT) should be recommended for treating uncomplicated Stanford type B aortic dissection (uSTBAD), whereas thoracic aortic endovascular repair (TEVAR) has been controversial for uSTBAD.

METHODS

In this paper, a meta-analysis was conducted on all available randomized controlled trials and observational studies that evaluated the relative benefits and harms of TEVAR and BMT for the management of patients suffering from uSTBAD. Primary endpoints consisted of early adverse events, long-term adverse events and aortic remodeling. In addition, Risk difference (RD) or Odds ratios (OR) with 95% confidence intervals (CI) were estimated. The random effects model or the fixed-effects model was used in accordance with the 50% heterogeneity threshold.

RESULTS

Seven observational studies and two RCT studies from 11 articles that contained 15066 patients suffering from uSTBAD (1518 TEVARs) met the inclusion criteria. For early outcomes, no significant differences were found between the TEVAR group and the BMT group in aortic rupture, retrograde dissection, paraplegia/paraparesis, reintervention, aorta-related death and all caused death. In the long run, the TEVAR group was found to have a significantly lower incidence of adverse events, which included aortic rupture (OR:0.26, CI:0.16∼0.42, P<0.05; heterogeneity: P=0.90, I²=0%), reintervention (OR:0.45, CI:0.26∼0.75, P<0.05; heterogeneity: P=0.17, I²=41%), aorta-related death (OR:0.27, CI:0.18∼0.42, P<0.05; heterogeneity: P=0.61, I²=0%) and all caused death (OR:0.52, CI:0.42∼0.66, P<0.05; heterogeneity: P=0.05, I²=53%) as compared with the BMT group. Moreover, in compared with BMT, TEVAR was found to significantly contribute to the complete thrombosis of thoracic false lumen (OR:55.34, CI:34.32∼89.21, P<0.05; heterogeneity: P=0.97, I²=0%) and aortic regression (true lumen expansion and false lumen shrinkage).

CONCLUSIONS

Although early endovascular repair of uSTBAD does not outperform BMT, its implementation is found to be necessary to facilitate the long-term prognosis. Accordingly, if early TEVAR is to be deferred, close follow-up is critical to allow for timely reintervention.

Mid- and long-term outcomes of thoracic endovascular aortic repair in acute and subacute uncomplicated type B aortic dissection

BACKGROUND

Uncomplicated type B aortic dissection (un-TBAD) has been managed conservatively with medical therapy to control the heart rate and blood pressure to limit disease progression, in addition to radiological follow-up. However, several trials and observational studies have investigated the use of thoracic endovascular aortic repair (TEVAR) in un-TBAD and suggested that TEVAR provides a survival benefit over medical therapy. Outcomes of TEVAR have also been linked with the timing of intervention.

AIMS

The scope of this review is to collate and summarize all the evidence in the literature on the mid- and long-term outcomes of TEVAR in un-TBAD, confirming its superiority. We also aimed to investigate the relationship between the timing of TEVAR intervention and results.

METHODS

We carried out a comprehensive literature search on multiple electronic databases including PubMed, Scopus, and EMBASE to collate and summarize all research evidence on the mid- and long-term outcomes of TEVAR in un-TBAD, as well as its relationship with intervention timing.

RESULTS

TEVAR has proven to be a safe and effective tool in un-TBAD, offering superior mid- and long-term outcomes including all-cause and aorta-related mortality, aortic-specific adverse events, aortic remodeling, and need for reintervention. Additionally, performing TEVAR during the subacute phase of dissection seems to yield optimal results.

CONCLUSION

The evidence demonstrating a survival advantage in favor TEVAR over medical therapy in un-TBAD means that with further research, particular trials and observational studies, TEVAR could become the gold-standard treatment option for un-TBAD patients.

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.

What is the optimal timing for thoracic endovascular aortic repair in uncomplicated Type B aortic dissection?

BACKGROUND

Uncomplicated Stanford Type B aortic dissection (un-TBAD) is characterized by a tear in the aorta distal to the left subclavian artery without ascending aorta and arch involvement. Optimized cardiovascular control (blood pressure and heart rate) is the current gold standard treatment according to current international guidelines. However, emerging evidence indicates that thoracic endovascular aortic repair (TEVAR) is both safe and effective in the treatment of un-TBAD with improved long-term survival outcomes in combination with optimal medical therapy (OMT) relative to OMT alone. However, the optimal timeframe for intervention is not entirely clarified.

AIMS

This review critically addresses current state-of-the-art comparing TEVAR with OMT and corresponding clinical outcomes for un-TBAD based on timing of intervention.

METHODS

We carried out a comprehensive literature search on multiple electronic databases including PUBMED and Scopus to collate all research evidence on timing of TEVAR in uncomplicated Type B aortic dissection.

RESULTS

TEVAR has proven to be a safe and effective treatment for un-TBAD in combination with OMT through comparable survival outcomes, improved aortic remodeling, and relatively low periprocedural added risks. Though the timing of intervention remains controversial, it is becoming clear that performing TEVAR during the subacute phase of un-TBAD yields better outcomes compared to earlier and delayed (>90 days) intervention.

CONCLUSIONS

Further research is required into both short- and long-term outcomes of TEVAR in addition to its optimal therapeutic window for un-TBAD. With stronger evidence, TEVAR is likely to be adopted as the gold-standard intervention for un-TBAD with definitive timeframe guidelines.

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

OBJECTIVE

To compare the 5-year outcomes of acute versus subacute thoracic endovascular aortic repair (TEVAR) in patients with uncomplicated acute type B aortic dissection (ATBAD).

METHODS

Between March 2008 and September 2018, 238 consecutive patients with uncomplicated ATBAD underwent TEVAR in the acute or subacute phase and were analyzed retrospectively. The primary end points were all-cause death and aortic-related death. The secondary end point was a composite of the outcomes of death from any cause, rupture, new dissection, retrograde type A aortic dissection, endoleak, and late reintervention. Inverse probability treatment weighting was used to balance baseline characteristics. Weight-adjusted Kaplan-Meier estimate with landmark analysis and weighted Cox model were performed to assess time-to-event outcomes.

RESULTS

In the inverse probability treatment weighting-adjusted population, the 30-day mortality was 1.5% in the acute TEVAR group and 0% in the subacute TEVAR group (P = .24). The incidence of 30-day adverse events occurred in 16.8% and 6.9% patients in the acute TEVAR and subacute TEVAR groups, respectively (P = .13). At 5 years, there was no statistically significant difference in all-cause death (hazard ratio [HR], 1.50; 95% confidence interval [CI], 0.59-3.81; P = .39) and aortic-related death (HR, 1.11; 95% CI, 0.34-3.60; P = .86) between the two groups. The composite outcomes occurred in 30 patients (23.0%) in the acute TEVAR group and 18 patients (22.3%) in the subacute TEVAR group, respectively (HR, 0.67; 95% CI, 0.36-1.25; P = .20). However, a landmark analysis of the composite outcomes indicated that there was a significant interaction between treatment effect and time (P_interaction = .01), with a significantly higher incidence of the composite outcomes in the acute TEVAR group compared with the subacute TEVAR group within 1 year (HR, 0.25; 95% CI, 0.08-0.79; P = .02), and a comparable rate between 1 and 5 years (HR, 1.25; 95% CI, 0.56-2.76; P = .59).

CONCLUSIONS

At the 5-year follow-up, no significant differences exist in the all-cause death and aortic-related death between acute and subacute TEVAR. However, acute TEVAR is associated with an increased rate of severe complications within 1 year, which suggests that performing TEVAR in the subacute phase of ATBAD may be the preferable option.

Long-term results of type B aortic dissection patients with tumor after endovascular repair or optimal medical therapy: a single-center and retrospective cohort study

BACKGROUND

The effect of thoracic endovascular aortic repair (TEVAR) for acute Type B aortic has been confirmed, However, when patients with malignant disease suffer from acute type B aortic dissection (ATBAD), the effect of TEVAR intervention is still unclear.

METHODS

ATBAD patients were identified from electronic medical records between 2009 and 2019. The 5 year overall and aortic-disease free survival rates were analyzed and compared between the two groups.

RESULTS

Of the 40 enrolled patients, 27 (67.5%) received TEVAR and 13 (32.5%) received OMT. The baseline characteristics of the two groups were not significantly different. Kaplan‒Meier survival curve showed that the 5 year overall survival and 5 year aortic-disease free survival of the TEVAR group were better than those of the OMT group. The Cox proportional hazard model with unadjusted risk showed an 83.0% decrease in 5 year overall mortality (HR, 0.17; 95% CI, 0.05-0.56) and a lower aortic-disease related risk (HR, 0.08; 95% CI, 0.02-0.39) in TEVAR group compared to OMT group. After adjusted for age, gender, smoking, drinking and comorbidities (diabetes mellitus, hypertension and coronary artery diseases), the hazard ratio of 5 year overall mortality was 78.0% lower (HR, 0.22; 95% CI, 0.06.0.81) and the risk of aortic-disease related mortality was 93.0% lower (HR, 0.07; 95% CI, 0.01-0.61) in TEVAR group compared to OMT group. In the cohort stratified by age, sex, the risk of the 5 year overall or aortic-disease related mortality in TEVAR group was relatively reduced compared to OMT group.

CONCLUSIONS

Compared to OMT, TEVAR improves the 5 year overall and aortic-disease free survival rates in the cohort of ATBAD patients with a single type of malignant tumors.

TEVAR for complicated and uncomplicated type B aortic dissection-Systematic review and meta-analysis

BACKGROUND

Type B aortic dissection (TBAD), is defined as a dissection involving the aorta distal to left subclavian artery with the ascending aorta and the aortic arch not affected. TBAD is classified due to the time frame and presence of complications. Complicated TBAD (co-TBAD) patients have a greater mortality rate than uncomplicated TBAD (un-TBAD) and thoracic endovascular aortic repair (TEVAR) is considered the gold-standard intervention for these clinical challenges.

METHODS

We undertook a systematic review of the literature regarding TEVAR intervention in co-TBAD and un-TBAD. A comprehensive search was undertaken across four major databases and was evaluated and assessed until June 2020.

RESULTS

A total of 16,104 patients were included in the study (7772 patients co-TBAD and 8352 un-TBAD). A significantly higher proportion of comorbidities were seen in co-TBAD patients compared with un-TBAD. Acute dissection was more frequent in the co-TBAD group (73.55% vs. 66.91%), while chronic dissection was more common in un-TBAD patients (33.8% vs. 70.73%). Postprocedure stroke was higher in co-TBAD (5.85% vs. 3.92%; p < .01), while postprocedural renal failure was higher in un-TBAD patients (7.23 vs. 11.38%; p < .01). No difference was observed in in-hospital mortality however the 30 days mortality was higher in the co-TBAD group. One-year survival was higher in the uncomplicated group but this difference was not observed in the 5-year survival.

CONCLUSION

In our analysis we can appreciate that despite significantly higher comorbidities in the co-TBAD cohort, there was no difference in in-hospital mortality between the two groups and the 5-year survival did not have any difference.

Predictors of adverse events in uncomplicated type B aortic dissection: a systematic review with meta-analysis

INTRODUCTION

Thoracic Endovascular Aortic Repair (TEVAR) has been selectively used for uncomplicated acute type B Aortic Dissection (TBAD); however, not all cases will benefit from TEVAR. A search for high risk clinical and radiographic predictors for complications is ongoing. This systematic review and meta-analysis aimed to identify predictors of major adverse events during follow-up of uncomplicated TBAD, in order to identify who might benefit from elective TEVAR.

EVIDENCE ACQUISITION

A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) statement.

EVIDENCE SYNTHESIS

16 studies were included in a qualitative synthesis and 10 in the meta-analysis. Several risk factors associated to major adverse events have been described, including (1) aortic diameter ≥40 mm, (2) greater false lumen diameter (>22mm), (3) patent false lumen, (4) primary entry tear > 10mm, and (5) greater number of false lumen vessels origin. Quantitative synthesis identified an aortic diameter ≥40 mm significantly associated with major adverse events (HR=3.56; p<0.00001). Reporting of false lumen status, aortic diameters and growth, and demographic data was not always congruent with the most recent recommendations by Society for Vascular Surgery and Society of Thoracic Surgeons, published in 2020.

CONCLUSIONS

Acute and subacute patients with uncomplicated TBAD presenting with an aortic diameter ≥ 40 mm and solely treated with BMT have an increased hazard of developing major adverse events (HR), making them potential candidates for TEVAR. Remaining risk factors analysed have weaker evidence.

Noninvasive Morphologic and Hemodynamic Evaluation of Type B Aortic Dissection: State of the Art and Future Perspectives

Stanford type B aortic dissection (TBAD) is associated with relatively high rates of morbidity and mortality, and appropriate treatment selection is important for optimizing patient outcomes. Depending on individualized risk factors, clinical presentation, and imaging findings, patients are generally stratified to optimal medical therapy anchored by antihypertensives or thoracic endovascular aortic repair (TEVAR). Using standard anatomic imaging with CT or MRI, several high-risk features including aortic diameter, false lumen (FL) features, size of entry tears, involvement of major aortic branch vessels, or evidence of visceral malperfusion have been used to select patients likely to benefit from TEVAR. However, even with these measures, the number needed to treat for TEVAR remains, and improved risk stratification is needed. Increasingly, the relationship between FL hemodynamics and adverse aortic remodeling in TBAD has been studied, and evolving noninvasive techniques can measure numerous FL hemodynamic parameters that may improve risk stratification. In addition to summarizing the current clinical state of the art for morphologic TBAD evaluation, this review provides a detailed overview of noninvasive methods for TBAD hemodynamics characterization, including computational fluid dynamics and four-dimensional flow MRI. Keywords: CT, Image Postprocessing, MRI, Cardiac, Vascular, Aorta, Dissection © RSNA, 2021.

Predicting reintervention after thoracic endovascular aortic repair of Stanford type B aortic dissection using machine learning

OBJECTIVES

To construct models for predicting reintervention after thoracic endovascular aortic repair (TEVAR) of Stanford type B aortic dissection (TBAD).

METHODS

A total of 192 TBAD patients who underwent TEVAR were included; 68 (35.4%) had indications for reintervention. Clinical characteristics, aorta characteristics on pre- and postoperative computed tomography angiography, and aorta characteristics on immediate postoperative aortic digital subtraction angiography were collected. The least absolute shrinkage and selection operator (LASSO) regression was applied to identify the risk factors for reintervention. Eight classifiers were used for modeling. The models were trained on 100 train-validation random splits with a ratio of 2:1. The performance was evaluated by the receiver operating characteristic curve.

RESULTS

Seven predictors of reintervention were identified, including maximum false lumen diameter, aortic diameter measured at the level of approximately 15 mm distal to the left subclavian artery, aortic diameter measured at the level of the diaphragm, false lumen diameter measured at the level of the celiac artery, number of bare-metal and covered stents, number of bare-metal stents, and residual perfusion of the false lumen. Logistic regression (LR) yielded the highest performance, with an area under the curve of 0.802. A nomogram built for clinical use showed good calibration. The cutoff value for dividing patients into low- and high-risk subgroups was 0.413. Kaplan-Meier curves showed that the overall survival of high-risk patients was significantly shorter than that of low-risk patients (both p < 0.05).

CONCLUSION

Our nomogram could predict the reintervention after TEVAR in patients with TBAD, which may facilitate patient selection and surveillance strategies.

KEY POINTS

• Seven risk factors of reintervention after TEVAR of TBAD were identified for modeling. • Logistic regression performed best in predicting reintervention with an AUC of 0.802. • Patients with a high risk of reintervention had shorter OS than those with a low risk.

Timing and Outcome of Endovascular Repair for Uncomplicated Type B Aortic Dissection

OBJECTIVE

This study aimed to determine the effect of intervention timing, from symptom onset to thoracic endovascular aortic repair (TEVAR), on early and late outcomes in high risk patients with uncomplicated type B aortic dissection (uTBAD).

METHODS

The study retrospectively evaluated 267 uTBAD patients with high risk radiographic features who underwent pre-emptive TEVAR during the acute and subacute periods. Demographics, comorbidities, pre-operative imaging features, peri-procedural details, and follow up outcomes were analysed.

RESULTS

Among the 267 pre-emptive TEVARs for high risk uTBAD, 130 were performed in the acute phase (1-14 days); and 137 in the subacute phase (15-90 days), from initial presentation. The mean age was 55.9 ± 11.0 years and 222 (83.1%) were men. The 30 day mortality rate in the acute group was five times higher than that in the subacute group (3.8% vs. 0.7%), although without statistically significant difference (p = .11). No statistically significant difference in 30 day outcomes (aortic rupture, retrograde type A dissection [RTAD], immediate type Ia endoleak, stroke, spinal cord ischaemia, and re-intervention) was noted (p > .05 for each). Of note, aortic rupture, RTAD, and disabling stroke were observed only in the acute group. Multivariable logistic analyses showed that intervention timing was not associated with 30 day outcomes. The median clinical follow up was 48.2 ± 25.9 months (range 1 - 106 months). There were no significant differences in all cause mortality, dissection related death, late intervention, or aortic related late events among timing cohorts (p > .05 for each). Furthermore, aortic remodelling, by analysing the flow status of the false lumen and evaluation of aortic diameters, either at the thoracic aorta level or the abdominal aorta level, was similar between the two groups. Multivariable Cox analyses showed that intervention timing was not associated with late outcomes.

CONCLUSION

The present study indicates that TEVAR for high risk uTBAD in the acute phase was associated with a trend toward higher rates of early complications, while the long term outcomes were comparable with those of the subacute phase.

Elevated preoperative neutrophil-to-lymphocyte ratio predicts early adverse outcomes in uncomplicated type B aortic dissection undergoing TEVAR

BACKGROUND

Thoracic aortic endovascular repair (TEVAR) of uncomplicated type B aortic dissection (uTBAD) has favorable long-term outcomes but higher early adverse events compared with the optimal medical treatment. Recently, clinical evidence concerning vascular surgery indicates that elevated preoperative systemic inflammatory response predicts adverse clinical events. The aim of our study was to evaluate the relationship between preoperative neutrophil-to-lymphocyte ratio (NLR) and early outcomes of uTBAD patients undergoing TEVAR.

RESULTS

216 patients diagnosed with uTBAD were included in this retrospective study between January 2015 and December 2018. The median (IQR) follow-up period was 21 (15-33) months. An early adverse event was defined as occurring within 2 years after the procedure. Median patient age was 60 (IQR, 48-68) years and 78.7 % were male. Early adverse events occurred in 24 patients (11.1 %). In the multivariable analysis, preoperative NLR (HR per SD, 1.98; 95 % CI, 1.14-3.44; P = 0.015) was associated with 2-year adverse events.

CONCLUSIONS

NLR is an independent predictive factor of early adverse events in uTBAD patients undergoing TEVAR.

Branch Vessel Patency after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) for type B aortic dissections is used to promote false lumen (FL) thrombosis and favorable aortic remodeling, but its impact on occlusion of FL origin branch vessels has not been widely described. We compare FL versus true lumen (TL) branch vessel patency after TEVAR.

METHODS

Patients treated by TEVAR for type B aortic dissection in zones 2-5 in the Vascular Quality Initiative from 2009 to 2018 were evaluated. The primary outcome was postoperative branch patency. Secondary outcomes were need for branch vessel intervention, preoperative origin, and postoperative patency of individual branch vessels (celiac, superior mesenteric artery, renal arteries, and iliac arteries). A subset analysis was performed comparing acute and chronic dissections.

RESULTS

Of 11,774 patients, 1,484 met criteria for analysis. The left renal was the most common to have FL origin (21.6%), whereas right and left common iliac arteries were the most likely to originate off both lumens (BLs; 22% and 24%). Branch vessels that originated from the TL, FL, BLs, or were obstructed had postoperative patency rates of 99%, 99%, 99%, and 87% (P < 0.0001). Branch vessel treatment was performed in 5% of patients. The right (2.5%) and left (2.8%) renal arteries were the most frequently obstructed branches postoperatively. On multivariate analysis, preoperatively obstructed branches (odds ratio 0.03, P < 0.0001) were negatively associated with postoperative branch patency and branch vessel treatment (odds ratio 3.8, P = 0.004) was positively associated with postoperative patency. FL or BL origin, number of zones covered by TEVAR, urgency, dissection chronicity (acute versus chronic), and demographics were not independently associated with patency. These findings remained unchanged in the subset analysis of only acute dissections.

CONCLUSIONS

Branch vessel patency rates after TEVAR for a type B aortic dissection are high and are not significantly different for FL or BL origin vessels compared with TL vessels. Branches that are patent before TEVAR almost always remain patent after TEVAR, but branch vessel stenting may be required in less than 5%.