Randomized comparison of strategies for type B aortic dissection: the INvestigation of STEnt Grafts in Aortic Dissection (INSTEAD) trial

Acute aortic dissection

Although substantial progress has been made in the prevention, diagnosis, and treatment of acute aortic dissection, it remains a complex cardiovascular event, with a high immediate mortality and substantial morbidity in individuals surviving the acute period. The past decade has allowed a leap forward in understanding the pathophysiology of this disease; the existing classifications have been challenged, and the scientific community moves towards a nomenclature that is likely to unify the current definitions according to morphology and function. The most important pathophysiological pathway, namely the location and extension of the initial intimal tear, which causes a disruption of the media layer of the aortic wall, together with the size of the affected aortic segments, determines whether the patient should undergo emergency surgery, an endovascular intervention, or receive optimal medical treatment. The scientific evidence for the management and follow-up of acute aortic dissection continues to evolve. This Seminar provides a clinically relevant overview of potential prevention, diagnosis, and management of acute aortic dissection, which is the most severe acute aortic syndrome.

Managing False Lumen Patency in Chronic Thoracic Aortic Dissecting Aneurysms With Coil Embolization

Thoracic endovascular aortic repair has become the preferred modality of treatment of complicated type B aortic dissections. However, persistent pressurization of the false lumen can lead to negative aortic remodeling with aneurysmal dilation. Described herein is the coil embolization technique that can be used to manage this complication and a review of the literature on the recent development of management options.

Endovascular aortic arch repair with chimney technique for pseudoaneurysm

BACKGROUND

Aortic pseudoaneurysm is a life-threatening clinical condition, and thoracic endovascular aortic repair (TEVAR) has been reported to have a relatively satisfactory effect in aortic pathologies. We summarized our single-centre experience using chimney TEVAR for aortic arch pseudoaneurysms with inadequate landing zones.

METHODS

A retrospective study was conducted from October 2015 to August 2020, 32 patients with aortic arch pseudoaneurysms underwent chimney TEVAR to exclude an aortic lesion and reconstruct the supra-aortic branches, including 3 innominate artery, 12 left common carotid arteries and 29 left subclavian arteries. Follow-up computed tomography was suggested before discharge; at 3, 6, 12 months and yearly thereafter.

RESULTS

The median age of 32 patients was 68.0 years (range, 28-81) with the mean max diameter of aneurysm of 47.9 ± 12.0 mm. Forty-four related supra-aortic branches were well preserved, and the technical success rate was 100%. The Type Ia endoleaks occurred in 3 (9%) patients. Two patients were lost to follow-up and 4 patients died during the follow-up period. The mean follow-up times was 46.5 ± 14.3 months. One patient died due to acute myocardial infarction just 10 days after chimney TEVAR and the other 3 patients passed away at 1.5 months, 20 months, and 31 months with non-aortic reasons. The 4.5-year survival estimate was 84.4%. The primary patency rate of the target supra-arch branch vessels was 97.7% (43/44), and no other aorta-related reinterventions and severe complications occurred.

CONCLUSION

For aortic arch pseudoaneurysms with inadequate landing zones for TEVAR, the chimney technique seems to be feasible, with acceptable mid-term outcomes, and it could serve as an alternative minimally invasive approach to extend the landing zone. Slow flow type Ia endoleak could be treated conservatively after chimney TEVAR. Additional experience is needed, and the long-term durability of chimney TEVAR requires further follow-up.

Rapid Morphological Measurement Method of Aortic Dissection Stent Based on Spatial Observation Point Set

OBJECTIVES

Post-operative stent morphology of aortic dissection patients is important for performing clinical diagnosis and prognostic assessment. However, stent morphologies still need to be manually measured, which is a process prone to errors, high time consumption and difficulty in exploiting inter-data associations. Herein, we propose a method based on the stepwise combination of basic, non-divisible data sets to quickly obtain morphological parameters with high accuracy.

METHODS

We performed the 3D reconstruction of 109 post-operative follow-up CT image data from 26 patients using mimics software. By extracting the spatial locations of the basic morphological observation points on the stent, we defined a basic and non-reducible set of observation points. Further, we implemented a fully automatic stent segmentation and an observation point extraction algorithm. We analyzed the stability and accuracy of the algorithms on a test set containing 8 cases and 408 points. Based on this dataset, we calculated three morphological parameters of different complexity for the different spatial structural features exhibited by the stent. Finally, we compared the two measurement schemes in four aspects: data variability, data stability, statistical process complexity and algorithmic error.

RESULTS

The statistical results of the two methods on two low-complexity morphological parameters (spatial position of stent end and vascular stent end-slip volume) show good agreement (n = 26, P₁, P₂ < 0.001, r₁ = 0.992, r₂ = 0.988). The statistics of the proposed method for the morphological parameters of medium complexity (proximal support ring feature diameter and distal support ring feature diameter) avoid the errors caused by manual extraction, and the magnitude of this correction to the traditional method does not exceed 4 mm with an average correction of 1.38 mm. Meanwhile, our proposed automatic observation point extraction method has only 2.2% error rate on the test set, and the average spatial distance from the manually marked observation points is 0.73 mm. Thus, the proposed method is able to rapidly and accurately measure the stent circumferential deflection angle, which is highly complex and cannot be measured using traditional methods.

CONCLUSIONS

The proposed method can significantly reduce the statistical observation time and information processing cost compared to the traditional morphological observation methods. Moreover, when new morphological parameters are required, one can quickly and accurately obtain the target parameters by new "combinatorial functions." Iterative modification of the data set itself is avoided.

Changing Management of Type B Aortic Dissections

The purpose of this manuscript is to review recent trends in the management of acute type B aortic dissection. Due to its efficacy and low morbidity, thoracic endografting has rapidly been adopted as the treatment of choice for most patients with malperfusion or rupture as a consequence of acute aortic dissection. This technology is increasingly applied to patients without rupture or malperfusion, so-called "uncomplicated" dissections, to reduce the incidence of late aneurysmal degeneration in the ungrafted segments of the thoracoabdominal aorta. A variety of techniques have been proposed, including intentional rupture of the dissection membrane to obliterate the false lumen as well as the candy-plug technique to eliminate retrograde flow in the false lumen.

Aortic arch surgery for type B aortic dissection: How far should we go? The value of a hybrid approach

Traditionally, the management of type B aortic dissection has been the domain of the vascular surgeons. Timing and type of intervention still generate debate. We sought to review our early experience with the treatment of this condition based on a hybrid approach following an aortic multi-disciplinary team meeting involving close cooperation between cardiac surgeons, vascular surgeons, interventional radiologists, vascular anesthetists, and cardiac anesthetists. Four patients (age 41-56 years; 3 males; 1 female) with type B aortic dissection underwent aortic arch surgery through a hybrid approach: one elective procedure consisting of ascending aorta and hemi-arch replacement with debranching followed by thoracic endovascular aortic repair (TEVAR); one redo procedure requiring aortic arch replacement with hybrid frozen elephant trunk; two acute presentations (aortic arch replacement and debranching followed by TEVAR; AVR with ascending aorta, arch, and proximal descending thoracic aorta replacement with conventional elephant trunk and debranching). Deep hypothermic circulatory arrest was required in three patients. Despite respiratory complications and slightly prolonged postoperative course, all patients survived without onset of stroke, paraplegia, malperfusion, endoleak, or need for re-exploration. Follow-up remains satisfactory. Different factors may affect outcome following complex aortic procedures. Nevertheless, close cooperation between cardiac surgeons, vascular surgeons, and interventional radiologists may reduce potential for complications and address aspects that may not be completely within the domain of individual specialists.

Endovascular treatment of complicated versus uncomplicated acute type B aortic dissection

OBJECTIVE

The study objective was to analyze the outcomes of thoracic endovascular aortic repair performed for complicated and uncomplicated acute type B aortic dissections.

METHODS

Patients from WL Gore's Global Registry for Endovascular Aortic Treatment who underwent thoracic endovascular aortic repair for acute type B aortic dissections were included, and data were retrospectively analyzed.

RESULTS

Of 5014 patients enrolled in the Global Registry for Endovascular Aortic Treatment, 172 underwent thoracic endovascular aortic repair for acute type B aortic dissections. Of these repairs, 102 were for complicated acute type B aortic dissections and 70 were for uncomplicated acute type B aortic dissections. There were 46 (45.1%) procedures related to aortic branch vessels versus 15 (21.4%) in complicated type B aortic dissections and uncomplicated type B aortic dissections (P = .002). The mean length of stay was 14.3 ± 10.6 days (median, 11; range, 2-75) versus 9.8 ± 7.9 days (median, 8; range, 0-42) in those with complicated type B aortic dissections versus those with uncomplicated acute type B aortic dissections (P < .001). Thirty-day mortality was not different between groups (complicated type B aortic dissections 2.9% vs uncomplicated acute type B aortic dissections 1.4%, P = .647), as well as aortic complications (8.8% vs 5.7%, P = .449). Aortic event-free survival was 62.9% ± 37.1% versus 70.6% ± 29.3% at 3 years (P = .696).

CONCLUSIONS

In the Global Registry for Endovascular Aortic Treatment, thoracic endovascular aortic repair results for complicated type B aortic dissections versus uncomplicated acute type B aortic dissections showed that 30-day mortality and perioperative complications were equally low for both. The midterm outcome was positive. These data confirm that thoracic endovascular aortic repair as the first-line strategy for treating complicated type B dissections is associated with a low risk of complications. Further studies with longer follow-up are necessary to define the role of thoracic endovascular aortic repair in uncomplicated acute type B dissections compared with medical therapy. However, in the absence of level A evidence from randomized trials, results of the uncomplicated acute type B aortic dissection patient cohort treated with thoracic endovascular aortic repair from registries are important to understand the related risk and benefit.

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.

Registry of Aortic Diseases to Model Adverse Events and Progression (ROADMAP) in Uncomplicated Type B Aortic Dissection: Study Design and Rationale

Purpose

To describe the design and methodological approach of a multicenter, retrospective study to externally validate a clinical and imaging-based model for predicting the risk of late adverse events in patients with initially uncomplicated type B aortic dissection (uTBAD).

Materials and Methods

The Registry of Aortic Diseases to Model Adverse Events and Progression (ROADMAP) is a collaboration between 10 academic aortic centers in North America and Europe. Two centers have previously developed and internally validated a recently developed risk prediction model. Clinical and imaging data from eight ROADMAP centers will be used for external validation. Patients with uTBAD who survived the initial hospitalization between January 1, 2001, and December 31, 2013, with follow-up until 2020, will be retrospectively identified. Clinical and imaging data from the index hospitalization and all follow-up encounters will be collected at each center and transferred to the coordinating center for analysis. Baseline and follow-up CT scans will be evaluated by cardiovascular imaging experts using a standardized technique.

Results

The primary end point is the occurrence of late adverse events, defined as aneurysm formation (≥6 cm), rapid expansion of the aorta (≥1 cm/y), fatal or nonfatal aortic rupture, new refractory pain, uncontrollable hypertension, and organ or limb malperfusion. The previously derived multivariable model will be externally validated by using Cox proportional hazards regression modeling.

Conclusion

This study will show whether a recent clinical and imaging-based risk prediction model for patients with uTBAD can be generalized to a larger population, which is an important step toward individualized risk stratification and therapy.Keywords: CT Angiography, Vascular, Aorta, Dissection, Outcomes Analysis, Aortic Dissection, MRI, TEVAR© RSNA, 2022See also the commentary by Rajiah in this issue.

Clinical Characteristics, Incidences, and Mortality Rates for Type A and B Aortic Dissections: A Nationwide Danish Population-Based Cohort Study From 1996 to 2016

BACKGROUND

Population-based epidemiologic studies of aortic dissections (ADs) are needed. This study aimed to report clinical characteristics, incidences, and mortality rates for adult patients admitted to Danish hospitals with type A AD (TAAD) or type B AD (TBAD) from 1996 through 2016.

METHODS

We conducted a nationwide, population-based register study. All cases of AD registered with International Classification of Diseases, Tenth Revision codes in the Danish National Patient Registry at time of admission to a hospital with available medical records underwent validation. Data were merged between nationwide health registries including the cause of death registry. Patients with validated AD were matched 1:10 on sex and age with patients with hypertension from the general Danish population.

RESULTS

Of 5018 registered cases of AD, 4183 cases underwent review and 3023 (60.2%) were validated as AD. After exclusions, the distribution of validated TAAD and TBAD was 1620 (60.5%) and 1059 (39.5%; P<0.001), 67.5% and 67.0% of patients were men, and mean ages at dissection were 63.5±12.9 and 67.5±12.2 years (P<0.001), respectively. The most prevalent comorbidities for TAAD were hypertension (55.2%), thoracic aortic aneurysms (14.6%), and chronic obstructive pulmonary disease (13.1%); for TBAD, the most prevalent comorbidities were hypertension (64.1%), aortic aneurysms at any location (7.5% to 12.0%), and chronic obstructive pulmonary disease (15.7%). The overall mean annual incidence rate was 4.2/100 000 patient-years. Incidence was significantly higher for TAAD (2.2/100 000) compared with TBAD (1.5/100 000; P<0.001). The 30-day mortality rates for validated TAAD and TBAD were 22.0% and 13.9% (P<0.001), respectively, with no significant changes over time or between sexes. Adjusted 5-year overall mortality rates for TAAD and TBAD were hazard ratio 3.2 (2.9 to 3.5; P<0.001; aortic-related cause of death, 57.0%) and hazard ratio 2.1 (1.9 to 2.4; P<0.001; aortic-related cause of death, 42.8%), respectively, compared with the general hypertensive population. Among patients who survived 30 days from dissection, the adjusted 5-year overall mortality rates were hazard ratio 1.1 (1.0 to 1.3; P=0.12; aortic-related cause of death, 23.2%) and hazard ratio 1.4 (1.2 to 1.6; P<0.001; aortic-related cause of death, 25.6%) for TAAD and TBAD, respectively.

CONCLUSIONS

Hypertension, aortic aneurysms, and chronic obstructive pulmonary disease were the most prevalent comorbidities. The 30-day mortality frequencies were consistent over time with no significant differences between sexes. The 5-year mortality rate was higher for TAAD than TBAD. If the patient survived 30 days from dissection, the mortality rate for patients with TAAD was comparable with that of the general hypertensive population, but the mortality rate was significantly higher in patients with TBAD.

13-year single-center experience with the treatment of acute type B aortic dissection

Background. Acute type B aortic dissection (TBAD) is catastrophic event associated with significant mortality and lifelong morbidity. The optimal treatment strategy of TBAD is still controversial. Methods. This analysis includes patients treated for TBAD at the Helsinki University Hospital, Finland in 2007-2019. The endpoints were early and late mortality, and intervention of the aorta. Results. There were 205 consecutive TBAD patients, 59 complicated and 146 uncomplicated patients (mean age of 66 ± 14, females 27.8%). In-hospital and 30-day mortality rates were higher in complicated patients compared with uncomplicated patients with a statistically significant difference (p = 0.035 and p = 0.015, respectively). After a mean follow-up of 4.9 ± 3.8 years, 36 (25.0%) and 22 (37.9%) TBAD -related adverse events occurred in the uncomplicated and complicated groups, respectively (p = 0.066). Freedom from composite outcome was 83 ± 3% and 69 ± 6% at 1 year, 75 ± 4% and 63 ± 7% at 5 years, 70 ± 5% and 59 ± 7% at 10 years in the uncomplicated group and in the complicated group, respectively (p = 0.052). There were 25 (39.1%) TBAD-related deaths in the overall series and prior aortic aneurysm was the only risk factor for adverse aortic-related events in multivariate analysis (HR 3.46, 95% CI 1.72-6.96, p < 0.001). Conclusion. TBAD is associated with a significant risk of early and late adverse events. Such a risk tends to be lower among patients with uncomplicated dissection, still one fourth of them experience TBAD-related event. Recognition of risk factors in the uncomplicated group who may benefit from early aortic repair would be beneficial.

Preemptive fenestrated endovascular repair aimed at perfusion of cervical branches in acute type B aortic dissection

OBJECTIVE

Most of the entry tears of uncomplicated type B aortic dissection are located in the distal arch and extends in a retrograde manner to the level of the left subclavian artery. Our objective was to evaluate feasibility and effectiveness using fenestrated sent graft with complete neck vessel preservation to treat uncomplicated type B aortic dissection.

SUBJECTS AND METHODS

We retrospectively reviewed the record of patients with uncomplicated type B aortic dissection who underwent fenestrated thoracic endovascular aortic repair in subacute phase (15-90 days) between August 2016 and April 2020. The Najuta fenestrated stent graft was placed proximally beyond he left subclavian artery (zone 0-2) in an attempt to seal the entry while preserving the neck vessels.

RESULTS

We evaluated 9 cases (male: 7, female: 2; median age 70 years). The median distance from the LSA to the proximal entry was 37 mm. The landing zones of the proximal end of the Najuta were zone 0: 3, zone 1: 2, and zone 2: 4 cases. Technical success was 100% with no 30-day death. None of the patients had a stroke, paraplegia or retrograde dissection, and no endoleak was observed. Complete aortic remodeling with false lumen resolution was obtained in all cases while each fenestrated vessels remained patent during the follow-up period.

CONCLUSION

Preemptive thoracic endovascular aortic repair aimed at perfusion of cervical branches using the Najuta fenestrated stent is safe and effective and may be considered as a reasonable treatment option for the treatment is a safe and an effective treatment.

Intensive care unit management of uncomplicated type B aortic dissection in relation to treatment period: a retrospective observational study

Background

Medical 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.

Methods

We 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.

Results

Fifty-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.

Conclusion

Long-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.

Shear-driven modelling of thrombus formation in type B aortic dissection

Background: Type B aortic dissection (TBAD) is a dangerous pathological condition with a high mortality rate. TBAD is initiated by an intimal tear that allows blood to flow between the aortic wall layers, causing them to separate. As a result, alongside the original aorta (true lumen), a false lumen (FL) develops. TBAD compromises the whole cardiovascular system, in the worst case resulting in complete aortic rupture. Clinical studies have shown that dilation and rupture of the FL are related to the failure of the FL to thrombose. Complete FL thrombosis has been found to improve the clinical outcomes of patients with chronic TBAD and is the desired outcome of any treatment. Partial FL thrombosis has been associated with late dissection-related deaths and the requirement for re-intervention, thus the level of FL thrombosis is dominant in classifying the risk of TBAD patients. Therefore, it is important to investigate and understand under which conditions complete thrombosis of the FL occurs.

Method: Local FL hemodynamics play an essential role in thrombus formation and growth. In this study, we developed a simplified phenomenological model to predict FL thrombosis in TBAD under physiological flow conditions. Based on an existing shear-driven thrombosis model, a comprehensive model reduction study was performed to improve computational efficiency. The reduced model has been implemented in Ansys CFX and applied to a TBAD case following thoracic endovascular aortic repair (TEVAR) to test the model. Predicted thrombus formation based on post-TEVAR geometry at 1-month was compared to actual thrombus formation observed on a 3-year follow-up CT scan.

Results: The predicted FL status is in excellent agreement with the 3-year follow-up scan, both in terms of thrombus location and total volume, thus validating the new model. The computational cost of the new model is significantly lower than the previous thrombus model, with an approximate 65% reduction in computational time. Such improvement means the new model is a significant step towards clinical applicability.

Conclusion: The thrombosis model developed in this study is accurate and efficient at predicting FL thrombosis based on patient-specific data, and may assist clinicians in choosing individualized treatments in the future.

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.

False lumen patency status and outcomes after endovascular repair of uncomplicated chronic type B dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) remains a controversial treatment for uncomplicated chronic type B aortic dissection (cTBAD). This study was performed to investigate the postoperative outcomes of TEVAR, such as survival and reintervention, and the risk factors for prognoses.

METHODS

In total, 41 patients with uncomplicated cTBAD who underwent TEVAR from 2014 to 2021 were reviewed. The patients were divided into two groups: those with false lumen complete thrombosis (FLCT) and false lumen partial thrombosis (FLPT) based on computed tomography angiography (CTA) images. Kaplan-Meier analysis was performed to estimate survival and freedom from reintervention. Binary logistic analysis was performed to estimate risk factors for partial thrombosis.

RESULTS

During a mean follow-up of 31 (1-78) months, five deaths and six reinterventions had occurred at 5 years. By 1 week, thoracic FLCT had occurred in 23 (56.1%) patients and thoracic FLPT had occurred in 18 (43.9%). The rate of freedom from reintervention was significantly lower in the FLCT than in the FLPT group (p = 0.04). The 5-year survival rate of the two groups was not statistically significant (p = 0.14). Risk factors for thoracic FLPT were the distance between the re-entry site and the graft (p = 0.02) and the proximal oversizing ratio (p = 0.04).

CONCLUSIONS

TEVAR is an effective and safe treatment for uncomplicated cTBAD and has a low mortality rate. Thoracic FLCT is associated with less reintervention, but overall survival is not impacted by this difference. Patients treated with TEVAR without certain risk factors can have a good prognosis.

Staged Hybrid Repair of a Complex Type B Aortic Dissection

Due to its heterogeneous clinical picture and lengthy evolution, the management of type B aortic dissection represents a clinical challenge, often calling for complex strategies combining medical, endovascular, and open surgical strategies. We present the case of a 45-year-old female who had previously suffered a complicated type B aortic dissection requiring a femoro-femoral crossover bypass and further conservative treatment. Seven years later, due to an aneurysmal development, a staged descending aortic management was strategized, beginning with the implantation of a frozen elephant trunk device due to an insufficient proximal landing zone for endovascular repair. However, the development of a distal stent graft-induced new entry complicated the dissection and led to the formation of a second false lumen, thus prompting an expedited hybrid reconstruction. We describe a hybrid repair strategy tailored to the patient’s particular aortic anatomic conformation, combining ilio-visceral debranching and thoracic endovascular aortic repair. Due to a lack of consensus on the ideal management strategy for type B aortic dissection, an individualized approach conducted by an experienced aortic team may generate the best outcome. The appropriate timing and planning of the intervention are the keys to successful results in complex type B aortic dissection cases with an elaborate anatomic conformation.

Comparison of Early Efficacy of the Percutaneous Presuture Technique with the Femoral Artery Incision Technique in Endovascular Aortic Repair under Local Anesthesia for Uncomplicated Type B Aortic Dissection

Objective

To compare the efficacy of the percutaneous presuture technique (PPST) and the femoral artery incision technique (FAIT) under local anesthesia in the treatment of endovascular aortic repair (EVAR) for patients with uncomplicated type B aortic dissection (uTBAD).

Method

Two hundred and ninety-five patients diagnosed with uTBAD who underwent EVAR under local anesthesia from June 2017 to December 2021 were consecutively and randomly selected for retrospective analysis. The PPST was performed in 178 cases and the FAIT was performed in 117 cases. The clinical characteristics and surgical and postoperative data from the two groups were analyzed.

Results

There were no significant differences in clinical characteristics between the two groups (p > 0.05). The operative time of the PPST group was significantly shorter than that of the FAIT group (46 (33, 58) versus 72 (67.5, 78.0) minutes, p < 0.001), as was the operative approach procedure time (6 (4.5, 9.0) versus 38 (36.5, 43.5) minutes, p < 0.001), and length of postoperative hospital stay (5.19 ± 2.26 versus 8.33 ± 3.76 days, p < 0.001). There were fewer postoperative approach-related procedural complications in the PPST group than in the FAIT group (2 versus 12, p < 0.001); similarly, the average frequency of postoperative wound disinfection was significantly lower in the PPST group (1.08 ± 0.39 versus 3.31 ± 0.91 times, p < 0.05). Obesity was identified as an independent risk factor for postoperative approach-related procedural complications (OR, 22.26; 95% CI, 4.74–104.49; p < 0.001).

Conclusions

The PPST has comparable safety and efficacy to the FAIT in EVAR under local anesthesia. It can shorten the length of hospital stay, reduce operation time, lower the risk of wound-related complications, reduce the frequency of postoperative wound disinfection, and hasten postoperative recovery. It can therefore be used as a first-line surgical technique in EVAR of uTBAD under local anesthesia, especially in obese patients.

Progressive Aortic Enlargement in Medically Managed Acute SVS/STS Type B Aortic Dissections with Visceral Aortic Involvement

BACKGROUND

Aortic remodeling of the thoracic aorta has been studied in patients treated with medical or endovascular therapy for the treatment of acute aortic dissections; however, particular attention has not yet focused on identifying specific growth patterns and rates across all aortic zones. Additionally, previous studies have not delineated between dissections with and without visceral aortic involvement, and we hypothesize that these two cohorts may exhibit distinct differences. The aim of this study is to investigate aortic behavior over time in medically managed acute SVS/STS Type B dissections with visceral aortic involvement, and identify potential associations of subsequent aortic behavior with clinical outcomes.

METHODS

A single-center retrospective review was performed of all patients between 2010-2020 with acute SVS/STS Type B aortic dissections with visceral aortic involvement that were not surgically managed. Short-axis centerline measurements of the true/false lumen and total aortic diameter (TAD) were taken at standardized locations relative to aortic anatomy within each aortic zone, including non-dissected zones. Measurements were taken at the time of diagnosis and at six subsequent yearly intervals. Diameter changes over time were evaluated using repeated measures mixed models linear growth analysis. Aortic enlargement was classified by growth in TAD≥5mm in either the thoracic (Thoracic Segment Enlargement [TSE], Zone 0-4) or visceral segments (Visceral Segment Enlargement [VSE], Zone 5-9).

RESULTS

A total of 78 patients were identified with a median length of follow-up of 3.3 years (interquartile range [IQR]1.3-6.6 years). Follow-up past 5 years was seen in 31% of the cohort. For the entire cohort, mean thoracic growth in TAD was 2.0±2.0 mm/year and visceral growth in TAD 2.5±2.4 mm/year. TSE was observed in 65% of patients, with a median time until onset of 0.8 years (IQR 0.4-2.3 years). VSE was observed in 57% of the cohort, with a median time until onset of 1.6 years (IQR 0.9-3.3 years). Repeat measures mixed models linear growth analysis identified significant predictable linear growth in all aortic zones except for the non-dissected Zones 0-2. Odds for TSE are significantly increased in patients with known genetically triggered aortic conditions (GenTACs) (OR 2, 95% CI 1.8-4.5, p=0.044) and in cases where the dissection entry tear was in either Zone 1 or 2 (OR 4.8, 95% CI 1.2-8.4, p=0.044). In adjusted regression analysis, odds for intervention in the thoracic aorta were significantly increased in patients with rapid TSE in Zone 3 (OR 3.6 [1.1-8.4], p=0.045). Similarly, odds for intervention targeting the visceral aortic segment were significantly increased in patients with Zone 9 VSE (OR 9.3, 95% CI 1.1-13.3, p=0.014). Odds for 5-year all-cause mortality were significantly increased in cases with large thoracic aneurysms (OR 6.1, 95% CI 1.1-14.9, p=0.042).

CONCLUSIONS

Aortic enlargement was present in the majority of patients with medically managed acute SVS/STS Type B aortic dissections with visceral aortic involvement, with analysis demonstrating predictable linear growth in all dissected zones. Patients with aortic instability demonstrated higher gross changes in diameter in addition to higher yearly rates of change compared to all comers. Odds for enlargement were impacted by both patient demographic and anatomic dissection characteristics. Growth in Zone 3 and Zone 9 significantly increased odds for aortic intervention. Odds for 5-year mortality were significantly increased in the presence of large thoracic aneurysms. Results highlight risk of progressive degeneration beyond acute phase in SVS/STS Type B aortic dissections with visceral aortic involvement, with life-long surveillance remaining crucial in management of dissections.

Research and clinical translation of trilayer stent-graft of expanded polytetrafluoroethylene for interventional treatment of aortic dissection

The aortic dissection (AD) is a life-threatening disease. The transcatheter endovascular aortic repair (EVAR) affords a minimally invasive technique to save lives of these critical patients, and an appropriate stent-graft gets to be the key medical device during an EVAR procedure. Herein, we report a trilayer stent-graft and corresponding delivery system used for the treatment of the AD disease. The stent-graft is made of nitinol stents with an asymmetric Z-wave design and two expanded polytetrafluoroethylene (ePTFE) membranes. Each of inner and outer surfaces of the stent-graft was covered by an ePTFE membrane, and the two membranes were then sintered together. The biological studies of the sintered ePTFE membranes indicated that the stent-graft had excellent cytocompatibility and hemocompatibility in vitro. Both the stent-graft and the delivery system exhibited satisfactory mechanical properties and operability. The safety and efficacy of this stent-graft and the corresponding delivery system were demonstrated in vivo. In 9 canine experiments, the blood vessels of the animals implanted with the stent-grafts were of good patency, and there were no thrombus and obvious stenosis by angiography after implantation for 6 months. Furthermore, all of the 9 clinical cases experienced successful implantation using the stent-graft and its post-release delivery system, and the one-year follow-ups indicated the preliminary safety and efficacy of the trilayer stent-graft with an asymmetric Z-wave design for interventional treatment.

Beta-blocker Use After Thoracic Endovascular Aortic Repair in Patients with Type B Aortic Dissection Is Associated with Improved Early Aortic Remodeling

OBJECTIVE

Beta-blockers are first-line anti-impulse therapy in patients presenting with acute type B aortic dissection (TBAD). However, little is understood about their impact after aortic repair. The aim of this study was to evaluate the role of postoperative beta-blocker use on outcomes of thoracic endovascular aortic repair (TEVAR) in TBAD.

METHODS

The Vascular Quality Initiative database was queried for all patients undergoing TEVAR for TBAD from 2012 to 2020. Aortic-related reintervention, all-cause mortality and effect of TEVAR on false lumen thrombosis of the treated aortic segment were assessed and compared between patients treated with and without beta-blocker postoperatively. Cox proportional hazards models were used to estimate the effect of beta-blocker therapies on outcomes.

RESULTS

1,114 patients undergoing TEVAR for TBAD were identified with a mean follow-up of 18±12 months. The mean age was 61.1±11.9 years, and 791 (71%) were male. 935 (84%) patients were maintained on beta-blocker at discharge and follow-up. Patients on beta-blocker were more likely to have an entry tear originating in zones 1-2 (22% vs 13%; P=.022). The prevalence of acute, elective and symptomatic AD, concurrent aneurysm, number of endografts used, distribution of the proximal and distal zones of dissection and operative time were comparable between the two cohorts. At 18-months, significantly more complete false lumen thrombosis (58 vs 47%; log-rank P=.018) was observed in patients on beta-blocker while the rates of aortic-related reinterventions (13% vs 9%; log-rank P=.396) and mortality (0.2% vs 0.7%; log-rank P=.401) were similar in patients with and without beta-blocker, respectively. Even after adjusting for clinical and anatomic factors, postoperative beta-blocker use was associated with increased complete false lumen thrombosis (HR 1.56; 95% CI: 1.10-2.21; P=.012) but did not affect mortality or aortic-related reintervention. A secondary analysis of beta-blocker use in acute versus chronic TBAD showed a higher rate of complete false lumen thrombosis in patients on beta-blocker in chronic TBAD (59% vs 38%; log-rank P=.038). In contrast, there was no difference in the rate of complete false lumen thrombosis in acute TBAD between the two cohorts (58% vs 51%; log-rank P=.158). When analyzed separately, postoperative ACE inhibitor use did not affect the rates of complete false lumen thrombosis, mortality and aortic-related reintervention.

CONCLUSIONS

Beta-blocker use was associated with promotion of complete false lumen in patients undergoing TEVAR for TBAD. In addition to its role in acute setting, anti-impulse control with beta-blocker appears to confer favorable aortic remodeling and may improve outcomes after TEVAR, particularly for chronic TBAD.

The misnomer of uncomplicated type B aortic dissection

BACKGROUND

Acute type B aortic dissection (TBAD) is a rare condition that can be divided into complicated (CoTBAD) and uncomplicated (UnCoTBAD) based on certain presenting clinical and radiological features, with UnCoTBAD constituting the majority of TBAD cases. The classification of TBAD directly affects the treatment pathway taken, however, there remains confusion as to exactly what differentiates complicated from uncomplicated TBAD.

AIMS

The scope of this review is to delineate the literature defining the intervention parameters for UnCoTBAD.

METHODS

A comprehensive literature search was conducted using multiple electronic databases including PubMed, Scopus, and EMBASE to collate and summarize all research evidence on intervention parameters and protocols for UnCoTBAD.

RESULTS

A TBAD without evidence of malperfusion or rupture might be classified as uncomplicated but there remains a subgroup who might exhibit high-risk features. Two clinical features representative of "high risk" are refractory pain and persistent hypertension. First-line treatment for CoTBAD is TEVAR, and whilst this has also proven its safety and effectiveness in UnCoTBAD, it is still being managed conservatively. However, TBAD is a dynamic pathology and a significant proportion of UnCoTBADs can progress to become complicated, thus necessitating more complex intervention. While the "high-risk" UnCoTBAD do benefit the most from TEVAR, yet, the defining parameters are still debatable as this benefit can be extended to a wider UnCoTBAD population.

CONCLUSION

Uncomplicated TBAD remains a misnomer as it is frequently representative of a complex ongoing disease process requiring very close monitoring in a critical care setting. A clear diagnostic pathway may improve decision making following a diagnosis of UnCoTBAD. Choice of treatment still predominantly depends on when an equilibrium might be reached where the risks of TEVAR outweigh the natural history of the dissection in both the short- and long-term.

Elevated Admission Cardiac Troponin I Predicts Adverse Outcomes of Acute Type B Aortic Dissection after Endovascular Treatment

Background

There is a lack of evidence about the predictive role of serum cardiac troponin I (cTnI) on the long-term adverse outcomes of acute type B aortic dissection (aTBAD) patients after thoracic endovascular aortic repair (TEVAR). In this study, we identified whether cTnI was an independent risk factor of 5-year adverse outcomes for aTBAD patients after TEVAR.

Methods

We reviewed consecutive aTBAD patients without previous heart disease who were admitted for TEVAR. The total study population was divided into the cTnI(+) group (≥0.03 ng/mL) and the cTnI(−) group (<0.03 ng/mL) according to the time-dependent receiver operating characteristic curve analysis. The differences in clinical characteristics, operative details and clinical outcomes were compared between the two groups.

Results

There was no difference in age and male prevalence between the two groups. Compared with the cTnI(−) group, the incidence of chronic kidney disease was higher in patients with cTnI ≥0.03 ng/mL. In addition, the cTnI(+) group presented with more frequent premature beats and non-myocardial-infarction ST-T segment changes. In terms of laboratory examinations, white blood cell counts, neutrophil counts, serum D-dimer and serum fibrin degradation products showed an increase in the cTnI(+) group, while lymphocyte and platelet counts showed a decrease in these patients. Patients with elevated cTnI suffered from increased risks of 5-year aortic-related adverse events (hazard ratio, HR = 1.822, 95% confidence interval, CI: 1.094–3.035; p = 0.021) and all-cause mortality (HR = 4.009, 95% CI: 2.175–7.388; p < 0.001).

Conclusion

Among aTBAD patients without previous heart disease, preoperative elevated cTnI identified patients at an increased risk of long-term adverse outcomes after TEVAR.

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.

Thoracic endovascular aortic repair or best medical therapy for uncomplicated type B aortic dissection? A meta-analysis

INTRODUCTION

The aim of this meta-analysis was to investigate all studies comparing thoracic endovascular aortic repair (TEVAR) and best medical therapy (BMT) for the treatment of uncomplicated type B aortic dissection (TBAD).

EVIDENCE ACQUISITION

PubMed/Medline and Web of Knowledge were searched until September 2014 for relevant studies published in English. Pooled odds ratio (OR) and its corresponding 95% CI were analyzed with Cochrane Review Manager (RevMan v.5.3).

EVIDENCE SYNTHESIS

Our analysis showed that compared with BMT, TEVAR did not significantly affect 30-day (hospital) mortality. A significantly lower 1-year and 2- or 3-year survival rates was observed with TEVAR vs. BMT. Interestingly, a trend just short of statistical significance towards higher 4- or 5-year survival was found with TEVAR treatment (P=0.08). No significant differences were found in false lumen (FL) thrombosis formation with TEVAR vs. BMT treatment. However, a trend toward less incomplete or no FL thrombosis was noted with TEVAR. No significantly impact on the risk of later re-intervention was found with TEVAR vs. BMT.

CONCLUSIONS

TEVAR did not provide obvious early survival advantage for uncomplicated TBAD over BMT, especially in the patients using TEVAR alone. It may remain a treatment option in uncomplicated TBAD patients with high risks for later complications. More randomized, prospective, long-term studies are needed to further clarify whether TEVAR could be a better first-line treatment strategy vs. BMT for uncomplicated TBAD.

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.

Long-Term Aortic Remodeling After Thoracic Endovascular Aortic Repair of Acute, Subacute, and Chronic Type B Dissections

Objective

This study aimed to investigate the characteristics and predictors of aortic remodeling over a long-term follow-up period after thoracic endovascular aortic repair (TEVAR) for acute, subacute, and chronic type B aortic dissections (TBADs).

Methods

Patients who underwent TEVAR for TBAD from July 2011 to December 2013 were included, and relevant data were retrospectively analyzed.

Results

After TEVAR, the true lumen (TL) dimension increased and the false lumen (FL) dimension decreased or did not change over a 5-year follow-up period in all three temporal groups. Shrinkage proportion of the thoracic aorta was the highest in the subacute group (acute, 28.1%; subacute, 39.1%; and chronic, 17.4%; p = 0.048), while abdominal expansion showed no significant differences among the groups (acute, 29.6%; subacute, 40.5%; and chronic, 44.4%; p = 0.502). The chronic group had a rate of complete FL regression, which is lower than the subacute or acute group at all anatomic sections, with significant differences only in the stented section (chronic, 21.7%; acute, 92.2%; and subacute, 80.4%; p < 0.05) and in the distal thoracic aortic section (chronic, 13.0%; acute, 31.1%; and subacute, 50.0%; p < 0.05). Logistic regression analysis demonstrated that chronic dissection, TL compression, endoleak, the number of branches from FL, and the number of residual tears affected optimal FL remodeling.

Conclusion

The present study provides data on aortic remodeling of TBAD after TEVAR during a long-term follow-up period. The features and risk factors of aortic remodeling in the acute, subacute, and chronic phases are different in different aortic segments. These findings may have implications in the timing of TEVAR.

Zone 2 hybrid thoracic endovascular aortic repair: Is it a good option for all types of thoracic aortic disease?

BACKGROUND

Zone 2 thoracic endovascular aortic repair (TEVAR) is performed for the treatment of various thoracic aortic diseases involving the left subclavian artery. This study aimed to analyze the late clinical outcomes of zone 2 hybrid TEVAR according to the various indications.

METHODS

A total of 48 patients who underwent zone 2 TEVAR at our institution between December, 2010 and July, 2020 were enrolled. The indications were aortic aneurysm (AA, n = 15), acute type B aortic dissection (AD, n = 14), penetrating aortic ulcer (PAU, n = 8), traumatic aortic injury (TAI, n = 8), and others (n = 3). The clinical outcomes including early complications and mid-term aortic measurements were retrospectively reviewed.

RESULTS

The technical success rate was 100% and in-hospital mortality occurred in one patient. The early postoperative complications included stroke (n = 1), transient spinal cord ischemia (n = 1), neck wound hematoma (n = 1), and left phrenic or vagus nerve injury (n = 9). In patients with AD, positive remodeling was observed in ten patients (76.9%) (false lumen regression in the entire or thoracic aorta [n = 9], false lumen thrombosis in the thoracic aorta [n = 1]). However, in patients with AA, increased aneurysm was found in six patients (40%). Persistent aneurysmal growth was found in patients with a maximal aortic diameter of > 60 mm on initial imaging (4/6, 50%). No aortic expansion was observed in those with TAI or PAU. Endoleak was noted in five patients (10.4%), and among them, aortic reintervention was required only in patients with large AAs.

CONCLUSIONS

Zone 2 hybrid TEVAR was associated with an acceptable early complication rate and provided acceptable mid-term aortic results for patients with AD, PAU, and TAI. However, patients with large AAs were at increased risk of aortic reintervention. In cases of large AA, clinicians should carefully consider whether zone 2 hybrid TEVAR or open surgical repair will be more effective for the patient.

The impact of dissection membrane motility on mid-term aortic remodelling after thoracic endovascular repair

OBJECTIVES

The aim of this study was to assess preoperative dissection flap motility and to evaluate its impact on the aortic remodelling and the development of distal stent-induced new entry after thoracic endovascular aneurysm repair (TEVAR)/frozen elephant trunk (FET).

METHODS

Patients with primary or residual type B dissections were included in a retrospective study with transoesophageal echocardiography analysis of the preoperative dissection flap motility assessed by the true lumen (TL) strain. Three-dimensional computing tomography centreline reconstructions before TEVAR/FET and during the follow-up were conducted to measure aortic remodelling: false lumen thrombosis, TL expansion and aortic diameters at 10 and 20 cm downstream the left subclavian artery, at the coeliac trunk and in the infrarenal aorta. All continuous variables are reported as median with first and third quartiles.

RESULTS

Fifty-six consecutive patients were treated with TEVAR (n = 45) or FET (n = 11) in the acute (n = 16), subacute (n = 16) and chronic (n = 24) dissection phase. At a median follow-up of 6 (3-12) months, they showed a favourable TL expansion in the descending aorta, significantly higher in the acute [+9 mm (5-12); P < 0.001] and subacute groups [+5 mm (3-8); P = 0.039] than in the chronic group [+2 mm (0-5)]. The dissection flap motility parameter TL strain was superior in the acute (P = 0.006) and subacute (P = 0.035) groups in comparison to the chronic group. The motile flap [TL strain >22.5% (median)] was associated with a higher TL expansion rate in the thoracic aorta (P = 0.009) and a comparable distal stent-induced new entry incidence (overall: 16%) in comparison to the immobile flap (P = 0.89).

CONCLUSIONS

The intraoperative assessment and the inclusion of the dissection flap motility parameters in the decision-making during TEVAR/FET may refine the distal endograft sizing for an improved remodelling of the TL.

Utility of 4D Flow MRI in Thoracic Aortic Diseases: A Literature Review of Clinical Applications and Current Evidence

Despite the recent technical developments, surgery on the thoracic aorta remains challenging and is associated with significant mortality and morbidity. Decisions about when and if to operate are based on a balance between surgical risk and the hazard of aortic rupture. These decisions are sometimes difficult in elective cases of thoracic aortic diseases, including aneurysms and dissections. Abnormal wall stress derived from flow alterations influences disease progression. Therefore, a better understanding of the complex hemodynamic environment inside the aortic lumen will facilitate patient-specific risk assessments of complications, which enable clinicians to provide timely prophylactic interventions. Time-resolved 3D phase-contrast (4D flow) MRI has many advantages for the in vivo assessment of flow dynamics. Recent developments in 4D flow imaging techniques has led to significant advances in our understanding of physiological flow dynamics in healthy subjects and patients with thoracic aortic diseases. In this clinically focused review of thoracic aortic diseases, we demonstrate the clinical advances acquired with 4D flow MRI from published studies. We provide a systematic overview of key evidences and considerations regarding normal thoracic aortas, thoracic aortic aneurysms, aortic dissections, and thoracic aortas with prosthetic graft replacement.

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.

Emergency Department Visits After Acute Aortic Syndromes

OBJECTIVES

Recent reports document a high rate of readmission after hospitalization for acute aortic syndromes (AAS) that include acute aortic dissections (AD), intramural hematomas (IMH), or penetrating aortic ulcers (PAU). We examined the rate of return to the emergency department (ED) to better understand the utilization of emergent health care services after AAS.

METHODS

Consecutive AAS patients admitted to the vascular surgery service from 2004 to 2020 were included. Patients with type A dissections, arch involvement, or chronic aortic pathology were excluded. The primary outcome was ED visits within 90 days of the original hospitalization.

RESULTS

The study included 79 subjects (62% men, 38% women; mean age, 64+14 years) with AAS (82% AD, 11% IMH, 6% PAU). A total of 54 ED visits related to the AAS occurred within 90 days of the original discharge, each of which incurred a CT angiogram. Twenty-eight (35%) subjects had a mean of 2+2 ED visits, while 51 (65%) subjects had no ED visits. Ninety percent (25/28) of the first ED visits occurred within 1 month of discharge and 53% (15/28) within one week. 17 (61%) subjects were readmitted to the hospital from the ED. Four subjects were found to have progression of AAS on imaging studies and underwent TEVAR during readmission. Comparing subjects who returned to the ED to those who did not, there were no significant differences in demographics, atherosclerotic risk factors except coronary artery disease, type of AAS, number of antihypertensive medications at admission or discharge, operative intervention, length of initial hospital stay, or discharge status. The chief complaint at the first ED visit was pain (n=17), uncontrolled hypertension (n=5), syncope (n=3), and other (n=3).

CONCLUSIONS

These data show that one in three patients with AAS returned to the ED within 90 days of initial discharge. Although returning subjects had a higher number of readmissions, few had progression of AAS that required intervention. Because the vast majority were readmitted for medical therapy, early and frequent clinic follow up may help decrease ED visits and readmissions after AAS.

Racial Disparities in Presentation and Short-Term Outcomes in Patients with Acute Type B Aortic Dissection

OBJECTIVE

Racial disparities in cardiovascular risk factors and disease outcomes are well documented. A knowledge gap exists on the role health maintenance plays in the development and outcomes of type B aortic dissection (TBAD). This study aims to evaluate the comparative presentation and short-term outcomes of patients with TBAD across race.

METHODS

In this single center retrospective study, TBAD patients admitted to the intensive care unit (ICU) were identified from 2015 to 2020. Patients self-identified as Black (N= 57) and White (N=123) were included. Groups were compared on variables including demographics, socioeconomic, pre-event health maintenance. Socioeconomic disadvantage was quantified based on The Area Deprivation Index (ADI). Management strategies included nonoperative and surgical repair. Outcomes were 30-day mortality, length of stay (LOS), and Acute Physiology and Chronic Health Evaluation (APACHE II) score.

RESULTS

The study included 180 consecutive patients with TBAD. TBAD included complicated (n= 42) and uncomplicated (n=138), of which (n=79) had high risk features. Blacks were younger than Whites (58.9 vs 67.6; p< 0.01), more likely to have end stage renal disease (ESRD) (8.8% vs 0.8%; p= 0.01) and to present with anemia (10.5% vs 2.4%; p=0.03). TBAD anatomic features and management were similar in both groups. Surgical intervention during hospitalization was 40% and 46% in Blacks and Whites, respectively (p= 0.4). Black patients were more likely to be on 3 or more hypertension agents, (42.2% vs 16.4%; p= 0.005) and less likely to be adherent to prescribed agents (27.1% vs 6.7%; p<0.001). Black patients had fewer primary care physician (PCP) visits prior to TBAD event (p= 0.03) and more Emergency Department (ED) utilization prior to TBAD, (57.9% vs 26.9% ;p < 0.001). Black patients had higher ADI scores, 86.0 ± 14.6 vs 64.4 ± 21.3 (p < 0.001). Median [IQR] APACHE II score was the same in both Blacks and Whites, 9[6, 12] and 9[7, 13] respectively (p=0.7). Hospital median LOS (days) was identical in both groups 7 [5, 13]. Readmission was 24.5% in Blacks vs 15.5% in Whites (p=0.16) with a 30-day mortality similar in Blacks 7.0% vs 5.7% Whites (p= 0.7).

CONCLUSION

Black patients present younger with similar dissection morphology, rate of anatomic high risk features and APACHE II scores. Fewer PCP visits, greater ED utilization, and higher ADI suggest lower health maintenance in Black patients. White patients with TBAD were also highly deprived of health maintenance compared to the national percentile, indicating that TBAD is a disease that affects vulnerable populations regardless of race.

Is Partially Thrombosed False Lumen Really a Predictor for Adverse Events in Uncomplicated Type B Aortic Dissection: A Systematic Review and Meta-Analysis?

Objective:

This meta-analysis and systematic review investigated whether partial thrombosed false lumen was a predictor for adverse events in uncomplicated Type B aortic dissection (TBAD).

Methods:

We performed the current systematic review of the medical literature according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The Newcastle-Ottawa Scale was used to evaluate the quality of individual studies. Search terms based on the MEDLINE database included “type B aortic dissection,” “false lumen” and “thrombosis.” The primary outcomes included mortality, intervention, and aortic growth.

Results:

Six studies were included in this systematic review, with a total number of 692 patients, including 197 patency (28.5%), 214 partial thrombosis (30.9%), and 281 complete thrombosis (40.6%). Due to the insufficient data for quantitative analysis, we only conducted a scoping review for mortality and intervention. For aortic growth, we conducted a meta-analysis based on Standardized Mean Difference (SMD). The SMD of PT vs. P by random effect model was −0.05 (random effect model) [95% confidence interval (CI), −0.39 to 0.29]. The 95% CI crossed with the null line of 0, indicating no significant difference. The SMD was 0.37 (fixed effects model) (95% CI, 0.03–0.71) and 0.70 (fixed effects model) (95% CI, 0.37–1.04) for PT vs. CT, and P vs. CT, respectively.

Conclusions:

Current researches on partial thrombosis of TBAD are inconsistent. Partial thrombosis is not associated with a faster aortic growth rate. Until more solid evidence is available, we do not recommend partial thrombosis as a surgical indication or high-risk profile for TBAD.

Systematic Review Registration: Unique Identifier: CRD42019121912.

GORE® TAG® conformable thoracic stent graft for the treatment of descending aortic pathologies

Endovascular repair of the descending thoracic aorta has gained widespread acceptance as a primary treatment modality for thoracic aortic disease due to its minimally invasive approach and improved survival rates. GORE^® TAG^® Conformable Thoracic Stent Graft was designed for descending thoracic aortic aneurysms, penetrating ulcers, aortic transections and type B aortic dissections, which are accepted indications for endovascular therapy. The aim of this review is to summarize the clinical literature, focusing mainly on the publications that came from manufacturer's pre-market and post-market studies. Including the Global Registry for Endovascular Aortic Treatment (GREAT), sponsored by WL Gore & Associates (Flagstaff, AZ, USA), which is a large database of endovascular repair of various thoracic, abdominal and thoraco-abdominal aortic pathologies to identify and evaluate only those with isolated thoracic aortic pathology (arch and descending thoracic).

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.

Thoracic endovascular aortic repair for uncomplicated Type B aortic dissection: What is the optimal time window for intervention?

BACKGROUND

Uncomplicated Type B aortic dissection (un-TBAD) is still managed conservatively with optimal medical therapy (OMT) despite evidence in favour of thoracic endovascular aortic repair (TEVAR) for un-TBAD. OMT aims to regulate heart rate and blood pressure and patients require long-term follow-up to evaluate the extent of dissection, however, many un-TBAD patients are lost to follow-up. Several trials and observational studies evaluated the use of TEVAR in combination with OMT in un-TBAD and proved the safety, effectiveness, and comparability of TEVAR relative to OMT alone. What remains in question is the optimal time window to intervene with TEVAR. This was recently addressed in a fascinating review by Jubouri et al. AIMS: This commentary aims to discuss the recent review by Jubouri et al. which further proved that TEVAR is safe and effective in un-TABD and investigated the optimal timing of TEVAR in un-TBAD.

MATERIALS & METHODS

We carried out a literature search using multiple electronic databases including PUBMED and Scopus in order to collate research evidence on intervention timeframe and outcomes of TEVAR in un-TBAD.

RESULTS

Performing TEVAR during the subacute phase of dissection (15-90 days since symptom onset) seems to be associated with less periprocedural complications compared to the acute phase, however, late outcomes (>30 days post-TEVAR) are comparable between the two groups and are superior to the chronic phase.

DISCUSSION

The introduction of TEVAR in un-TBAD presents a paradigm shift in the management of un-TBAD and a potential move towards becoming the gold-standard treatment option for un-TBAD. Intervening with TEVAR within the first 90 days since symptom onset (acute and subacute un-TBAD) gives favourable outcomes relative to intervention in the chronic phase of dissection (>90 days since symptom onset), this is due to the dissecting septum becoming less compliant over time.

CONCLUSION

TEVAR is a safe and effective treatment modality for un-TBAD with a survival benefit compared to OMT alone. Offering TEVAR during the subacute phase of dissection yields optimal results which are comparable to the acute phase but superior to the chronic phase.