False Lumen Status in Patients With Acute Aortic Dissection: A Systematic Review and Meta-Analysis

Design, evolution, and experience with the candy plug device for endovascular false lumen occlusion of chronic aortic dissections

INTRODUCTION

The management of the false lumen (FL) when dealing with aortic dissection is a crucial aspect since inducing its thrombosis is necessary in order to achieve aortic remodeling. One of the pitfalls of endovascular treatment of aortic dissection (AD) is retrograde distal FL perfusion and pressurization, which prevents FL thrombosis and thus aortic remodeling, while being associated with aneurysmal degeneration of the FL and poor long-term outcomes.

AREAS COVERED

Currently, there is no CE/FDA approved device for FL closure, however different techniques and devices have been proposed to overcome this challenge, the most known of which is the Candy Plug (CP). This review aims to describe the CP device, its implantation technique, and the available data in the literature (PubMed, Cochrane, and EMBASE databases; last queried, December 31, 2023).

EXPERT OPINIONS

While the treatment of AD remains technically challenging, the use of the CP technique to close any distal FL reperfusion proved to be feasible and safe with excellent rates of both technical and clinical success. Furthermore, recent studies have shown a quick learning curve with this technique.

Morphologic prognostic factor for thoracoabdominal aortic dilation after acute type A dissection repair

OBJECTIVES

Risk factors for late-term aortic dilation after acute type A aortic dissection repair have not been well examined. The goal of this study was to determine the relationship between the abdominal aortic true lumen location and thoraco-abdominal aortic dilation after surgical repair for acute type A aortic dissection.

METHODS

Patients who were preoperatively diagnosed with acute type A aortic dissection between April 2014 and July 2022 were included in this study. We evaluated the renal artery-level dissected aortic morphology and classified the study population into 2 groups: the ventral (those with the true lumen located on the ventral side) and the dorsal (other patients not assigned to the ventral group) groups, based on the location of the true lumen. Aortic dilation was defined as thoraco-abdominal aortic expansion ≥5 mm on 1-year postoperative computed tomography images.

RESULTS

We examined 49 surgical patients who were assigned to the ventral (n = 22) and dorsal (n = 27) groups. The number of patients with ≥5 mm thoraco-abdominal aortic dilation after the operation was significantly higher in the ventral group than in the dorsal group (90.9% vs 51.9%, P = 0.009). The multivariable logistic regression analysis showed that the ventral type was an independent prognostic factor for thoraco-abdominal aortic dilation after the operation (odds ratio, 6.01; 95% confidence interval, 1.56-23.77; P = 0.009).

CONCLUSIONS

The location of the true lumen of the abdominal aorta in acute type A aortic dissection may be a prognostic factor for thoraco-abdominal aortic dilation after surgical repair.

Long-term outcomes after recurrent acute thoracic aortic dissection: Insights from the International Registry of Aortic Dissection

OBJECTIVE

With an aging population and advancements in imaging, recurrence of thoracic aortic dissection is becoming more common.

METHODS

All patients enrolled in the International Registry of Aortic Dissection from 1996 to 2023 with type A and type B acute aortic dissection were identified. Among them, initial dissection and recurrent dissection were discerned. The study period was categorized into 3 eras: historic era, 1996 to 2005; middle era, 2006 to 2015; most recent era, 2016 to 2023. Propensity score matching was applied between initial dissection and recurrent dissection. Outcome of interests included long-term survival and cumulative incidence of major aortic events defined by the composite of reintervention, aortic rupture, and new dissection.

RESULTS

The proportion of recurrent dissection increased from 5.9% in the historic era to 8.0% in the most recent era in the entire dissection cohort. In patients with type A dissection, propensity score matching between initial dissection and recurrent dissection yielded 326 matched pairs. Kaplan-Meier curves showed similar long-term survival between the 2 groups. However, the cumulative incidence of major aortic events was significantly higher in the recurrent dissection group (40.3% ± 6.2% vs 17.8% ± 5.1% at 4 years in the initial dissection group, P = .02). For type B dissection, 316 matched pairs were observed after propensity score matching. Long-term survival and the incidence of major aortic events were equivalent between the 2 groups.

CONCLUSIONS

The case volume of recurrent dissection or the ability to detect recurrent dissection has increased over time. Acute type A recurrent dissection was associated with a higher risk of major aortic events than initial dissection. Further judicious follow-up may be crucial after type A recurrent dissection.

Hybrid noncovered open stents in repair of DeBakey type 1 acute aortic dissections

OBJECTIVES

The indications for use, evidence base and experience with the novel noncovered open hybrid surgical stents for acute type A aortic dissection repair for concurrent stabilization of the 'downstream' aorta remains limited. We review the evidence base and the development of these stents.

METHODS

Data were collected from Pubmed/Medline literature search to develop and review the evidence base for safety and efficacy of non-covered surgical stents. Existing guidelines for use and developments were reviewed.

RESULTS

A single randomized control trial and 4 single-centre studies were included in the review with a total worldwide experience of 241 patients. The deployment was easy and did not add significantly to the primary operation. The mortality and new stroke ranged from 6.3-18.7%. Safe and complete deployment was accomplished in 92-100%. There was no device-related reintervention. There was a significant improvement in malperfusion in over 90% of the cases with varying degrees of remodelling (60-90%) of the downstream aorta.

CONCLUSIONS

Open noncovered stent grafts represent a major technical advancement as an adjunct procedure for acute dissection repairs, e.g. hemiarch repair. It has potential for wider use by non-aortic surgeons due to simplicity of technique. Limited safety and efficacy data confirm the device to be safe, feasible and reproducible with potential for wider adoption. However, long-term trial and registry data are required before recommendations for standard use outside of high-volume experienced aortic centres.

Proximalization of Frozen Elephant Trunk Procedure: Zone 0 or 1 versus Zone 2 or 3 Arch Repair

BACKGROUND

 Total arch replacement with the frozen elephant trunk (FET) procedure has changed the landscape of therapy for aortic arch diseases. The optimal landing zone for a FET is controversial. We sought to share our early and midterm results of the FET procedure as well as compare the clinical outcomes of proximal and distal FET anastomosis.

METHODS

 A total of 100 patients who underwent total arch replacement using the FET technique were identified between November 2014 and August 2021. According to the FET anastomosis over the aortic arch, patients were classified into two groups (zone 0/1 vs. zone 2/3). In-hospital mortality, complications, and midterm outcomes were assessed based on patient characteristics.

RESULTS

 The overall in-hospital mortality was 8%. Major complications occurred in 32% of patients, including spinal cord injury (5%), stroke (7%), and acute kidney injury requiring dialysis (7%). Zone 2/3 FET (odds ratio: 6.491, 95% confidence interval: 1.930-21.835, p = 0.003) was an independent predictor of the composite endpoint of major complications. The rate of complete false lumen thrombosis was comparable (64.3% vs. 71.4%, p = 0.567). All patients, patients with zone 0/1 FET, and patients with zone 2/3 FET had 3-year freedom from aorta-related events of 73.0, 70.2, and 75.0%, respectively. There were no significant differences (log-rank test, p = 0.500).

CONCLUSION

 Compared with zone 2/3, proximalization of FET using zone 0/1 for anastomosis was associated with better early outcomes and comparable rates of midterm aorta-related events. To substantiate its use, more research on this approach is required.

STABILISE (Stent-Assisted Balloon-Induced Intimal Disruption and Relamination in Aortic Dissection Repair) Is Associated With Good Anatomical Results on the Distal Thoracoabdominal Aorta at 2 Years

PURPOSE

The aim of this comparative study was to evaluate the increased aortic diameter of the distal aorta after implementing the STABILISE technique in complicated type B aortic dissection (AD).

DESIGN

This is a comparative monocentric retrospective study.

MATERIALS AND METHODS

All patients who underwent an STABILISE procedure for complicated AD between 2018 and 2020 were included and compared with a historic cohort treated with thoracic endovascular aortic repair (TEVAR) alone. Aortic diameters were measured at 6 different levels on the thoracic and abdominal aorta. The primary end point was an increased aortic diameter at 1 and 2 years. The exclusion criterion was the absence of a computed tomography (CT) scan at 1 or 2 years.

RESULTS

A total of 55 patients were included: 24 in the TEVAR group and 31 in the STABILISE group. At the level of the stent graft, there was a decrease in aortic diameters in both groups without significant differences. At the level of the distal aorta, there was an increase in aortic diameters in both groups without significant differences. There were significantly more patients in the TEVAR group with an unfavorable increase in aortic diameter >5 mm of the distal aorta at 2 years than in the STABILISE group: 8 (33%) vs 1 (3%) (p=0.01). For chronic ADs, a significantly greater increase in aortic diameters of the distal aorta was observed in the STABILISE group.

CONCLUSIONS

The STABILISE technique is technically feasible and potentially leads to decreased longer re-intervention rates; indeed, more patients had an unfavorable increase in aortic diameter in the TEVAR group than in the STABILISE group at 2 years. The high rate of long-term distal aortic aneurysm progression and reintervention after TEVAR alone suggests that this option is not sufficient to definitively treat these complex patients.

CLINICAL IMPACT

This article reported the results of stent assisted balloon induced intimal disruption and relamination (STABILISE) with a follow-up at 2 years. This is the first comparative study between STABILISE, which has emerged as a new technique inducing aortic remodeling and therefore better long-term outcome, and the standard technique TEVAR alone. STABILISE technique is associated with good results on the distal aorta at 2 years with a rate of patient with unfavorable aortic diameter evolution greater in TEVAR group compared to STABILISE group and could improve the long-term results on the distal aorta by inducing extensive aortic remodeling.

Relationship between false lumen morphology and entry tear in acute type A aortic dissection

OBJECTIVES

This study aimed to investigate the relationship between false lumen morphology and the size, aortic segment and position of the entry tear for acute type A aortic dissection.

METHODS

The records of patients who underwent emergency operation for acute type A aortic dissection in our institution between April 2011 and May 2022 were examined. Data regarding size, location and position of the entry tear and preoperative computed tomography findings were reviewed. The relationship of these variables with false lumen morphology was examined and retrospectively compared according to tear size.

RESULTS

Of 243 cases, characteristics of the entry tear, visualized during surgery, were confirmed in 134 cases (age = 70.9 ± 12.6 years, male = 45.5%). Tear sizes at different aortic segments were not significantly different (P = 0.376). Tears posterior to the lesser curvature were significantly smaller than those anterior to the greater curvature (P = 0.004). A thrombosed false lumen was associated with a significantly smaller tear size and position on the posterior to the lesser curvature side in aortic cross-section (all P < 0.001). Multivariate analysis showed that tear size, the presence of re-entry and tear position anterior to the greater curvature were independent predictors of a patent false lumen.

CONCLUSIONS

In acute type A aortic dissection, larger tear size, the presence of re-entry and tear position anterior to the greater curvature are risk factors for a patent false lumen. Although the results of this study are valid only for patients in whom intimal tears were detected during aortic surgery, this trend may provide information for pathophysiology of the disease.

Open and endovascular reinterventions after Candy Plug false lumen embolization of type B aortic dissection

OBJECTIVE

In the majority of patients with chronic type B aortic dissection, there is persistent retrograde flow in the false lumen (FL) through distal re-entry tears. Among several endovascular techniques proposed for FL management, the "Candy Plug" (CP) technique has gained acceptance with good early results. The aim of this study is to report the types and outcomes of open and endovascular reinterventions and identify mechanisms of procedure failure as well as other causes for reinterventions.

METHODS

All patients with type B aortic dissection submitted to thoracic endovascular aneurysm repair and CP implantation for FL embolization from January 2016 to December 2022 at our institution were included in this study. The preoperative, intraoperative, and postoperative data of the primary intervention and secondary reinterventions, when performed, were prospectively collected and retrospectively analyzed. Preoperative and postoperative computed tomography angiography were also analyzed.

RESULTS

During the study period, 33 patients were submitted to thoracic endovascular aneurysm repair and CP implantation. Twenty-three patients (69.7%) showed thoracic FL complete thrombosis with aortic stability or positive remodeling at a mean follow-up of 45 ± 23.1 months. Ten patients (30.3%) underwent aortic reinterventions (male, n = 9; mean age, 60.5 ± 7.6 years). Of these 10 patients, in four patients, complete thrombosis of the FL was never achieved, leading to ongoing perfusion of the FL, defined as "primary failure." The other six patients underwent reinterventions for different causes: two patients, after initial sealing, showed a progressive enlargement of the abdominal FL leading to distal degeneration. One patient showed proximal degeneration, two patients showed a type II thoracoabdominal aortic aneurysm and CP implantation was used as a planned procedure to reduce the extent of the surgical procedure, and one patient had recurrent, intractable back pain despite complete thrombosis of the FL. Reinterventions were open in five cases and endovascular in five. One in-hospital death (postoperative day 27) after a type II thoracoabdominal aortic aneurysm open repair was recorded. In addition, two cases of delayed spinal cord ischemia after open reintervention were recorded: one resulting in permanent paraplegia and one transitory with complete recovery.

CONCLUSIONS

The CP technique was safe and effective; however, a significant rate of aortic-related reintervention was observed. Several mechanisms led to reinterventions either in terms of "primary failure" of the CP or subsequent aneurysmal degeneration. Complex reinterventions were often necessary, with a high rate of major complications in case of open repair. Life-long and closer surveillance might be required in these patients.

Oxidative stress drives vascular smooth muscle cell damage in acute Stanford type A aortic dissection through HIF-1α/HO-1 mediated ferroptosis

Background

Acute Stanford type A aortic dissection (ATAAD) is characterized by intimal tearing and false lumen formation containing large amounts of erythrocytes with heme. Heme oxygenase 1 (HO-1) is the key enzyme to degrade heme for iron accumulation and further ferroptosis. The current study aimed at investigating the role of HO-1 in the dissection progression of ATAAD.

Methods

Bioinformatic analyses and experimental validation were performed to reveal ferroptosis and HO-1 expression in ATAAD. Human aortic vascular smooth muscle cell (HA-VSMC) was used to explore underlying molecular mechanisms and the role of HO-1 overexpression in ATAAD.

Results

Ferroptosis was identified as a critical manner of regulated cell death in ATAAD. HO-1 was screened as a key signature of ferroptosis in ATAAD, which was closely associated with oxidative stress. Single cell/nucleus transcriptomic analysis and histological staining revealed that HO-1 and HIF-1α were upregulated in vascular smooth muscle cell (VSMC) of ATAAD. Further in vitro experiments showed that H2O2-induced oxidative stress increased VSMC ferroptosis with the overexpression of HO-1, which could be suppressed by HIF-1α inhibitor PX-478. HIF-1α could transcriptionally regulate the expression of HO-1 through binding to its promoter region. Pharmacological inhibition of HO-1 by zinc protoporphyrin (ZnPP) did not reduce H2O2-induced HA-VSMC damage without heme co-incubation. However, H2O2-induced HA-VSMC damage was worsened when heme was added into the medium, and ZnPP could reduce HA-VSMC damage in this condition.

Conclusion

HO-1 is a key signature of VSMC ferroptosis in ATAAD. HIF-1α/HO-1 mediated ferroptosis might participate in oxidative stress induced VSMC damage.

Sizing the Frozen Elephant Trunk Based on Aortic Pathology and the Importance of Pre-Operative Imaging

The frozen elephant trunk is a formidable tool for the aortovascular surgeon. An appreciation of how to size the graft in different pathologies is key in achieving optimal results. Herein, we demonstrate worked examples of how imaging can be used to plan for a frozen elephant trunk and discuss the nuisances and uncertainties of sizing using three index cases: Type A aortic dissection, distal thoracic aortic aneurysm and chronic dissection.

The effect of postoperative anticoagulation on acute aortic dissection: a systematic review and meta-analysis

Background and aim

The evolution of the false lumen after the repair of acute aortic dissection has been linked to numerous adverse clinical outcomes, including increased late mortality and a higher risk of reoperation. Despite the widespread use of chronic anticoagulation in patients who have undergone repair for acute aortic dissection, the effects of this therapy on false lumen evolution and its subsequent consequences are yet to be fully understood. This meta-analysis aimed to investigate the impact of postoperative anticoagulation on patients with acute aortic dissection.

Methods

In PubMed, Cochrane Libraries, Embase, and Web of Science, we performed a systematic review of nonrandomized studies, comparing outcomes with postoperative anticoagulation vs. non-anticoagulation on aortic dissection. We investigated the status of false lumen (FL), aorta-related death, aortic reintervention, and perioperative stroke in aortic dissection patients with anticoagulation and non-anticoagulation.

Results

After screening 527 articles, seven non-randomized studies were selected, including a total of 2,122 patients with aortic dissection. Out of these patients, 496 received postoperative anticoagulation while 1,626 served as controls. Meta-analyses of 7 studies revealed significantly higher FL patency in Stanford type A aortic dissection (TAAD) postoperative anticoagulation with an OR of 1.82 (95% CI: 1.22 to 2.71; Z = 2.95; I²=0%; P = 0.93). Moreover, there was no statistically significant difference between the two groups in aorta-related death, aortic reintervention, and perioperative stroke with an OR of 1.31 (95% CI: 0.56 to 3.04; Z = 0.62; I² = 0%; P = 0.40), 0.98 (95% CI: 0.66 to 1.47; Z = 0.09; I² = 23%; P = 0.26), 1.73 (95% CI: 0.48 to 6.31; Z = 0.83; I² = 8%; P = 0.35), respectively.

Conclusions

Postoperative anticoagulation was associated with higher FL patency in Stanford type A aortic dissection patients. However, there was no significant difference between the anticoagulation and non-anticoagulation groups in terms of aorta-related death, aortic reintervention, and perioperative stroke.

Prognostic value of interleukin-33, sST2, myeloperoxidase, and matrix metalloproteinase-9 in acute aortic dissection

Background and purpose

Acute aortic dissection (AAD) is a life-threatening cardiovascular emergency. Both neutrophil granzyme and interleukin (IL)-33/ST2 systems have proven to be effective diagnostic markers for AAD. This study aimed to investigate the relationship between plasma IL-33, soluble suppression of tumorigenesis-2 (sST2), myeloperoxidase (MPO), and matrix metalloproteinase (MMP)-9 levels at admission and all-cause mortality in patients with AAD.

Methods

A total of 155 patients with AAD were enrolled from the Prospective Evaluation of Acute Chest Pain (PEACP) study. Plasma concentrations of IL-33, sST2, and MMP-9 were measured using an enzyme-linked immunosorbent assay, and MPO was detected using a chemiluminescence immunoassay. Aortic anatomical parameters were measured using CT radiography. The primary endpoint was all-cause mortality rate.

Results

The median age of the patients was 55 years, and 96 (61.9%) were diagnosed with type A-AAD. After adjusting for confounding factors, the highest tertiles of IL-33, sST2, MPO, and MMP-9 had hazard risks of 0.870 (95% CI: 0.412-1.836, P = 0.714), 3.769 (95% CI: 1.504-9.446, P = 0.005), 4.689 (95% CI: 1.985-11.076, P < 0.001), and 4.748 (95% CI: 1.763-12.784, P = 0.002), respectively, compared to the lowest tertile. Pearson's correlation analysis revealed a significant correlation between these markers (P < 0.001). Moreover, sST2, MPO, and MMP-9 levels had a significant positive correlation with aortic diameter and pseudolumen area (P < 0.001).

Conclusion

The biomarkers sST2, MPO, and MMP-9 were independently associated with mortality in patients with AAD. The significant correlation between these biomarkers suggests a pathogenic role for the IL-33/ST2/neutrophil granzyme system in patients with AAD.

Use of Anti-Thrombotic Drugs and In-Hospital Mortality in Acute Aortic Dissection Patients

Acute aortic dissection occurs due to a primary tear in the aortic intima, with blood from the aortic lumen entering the adjacent diseased media. In the clinical setting, practitioners often hesitate before the use of anti-thrombotic drugs in the acute phase of aortic dissection. Therefore, we examined the clinical course in patients who had already received antithrombotic therapies at the onset of acute aortic dissection, and who were given anti-thrombotic drugs in the acute phase during hospitalization. We retrospectively enrolled 685 consecutive patients with acute aortic dissection (type A/B: 454/231), who were transferred to Kurume University Hospital from 2004 to 2020. In types A and B, there were no significant differences between in-hospital mortality with or without antithrombotic therapies at the onset (14.3% vs. 16.4%, p = 0.66 in type A, 2.6% vs. 7.3%, p = 0.29 in type B). Patients in type A who survived more than a day and were treated with anti-thrombotic drugs during hospitalization had significantly lower in-hospital mortality compared with those who received no anti-thrombotic drugs in the acute phase (2.2% vs. 16.1%, p < 0.001), while there was no significant difference between in-hospital mortality in the two type-B groups (2.4% vs. 4.9%, p = 0.48). Although there were variations in response among patients with acute aortic dissection, anti-thrombotic drugs did not worsen in-hospital mortality for patients with acute aortic dissection, indicating that medical staff should not hesitate to administer anti-thrombotic drugs if indicated.

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.

[Chronic type B aortic dissection-what to do?]

BACKGROUND

Chronic type B aortic dissection requires optimal medical therapy. However, secondary complications like organ or extremity malperfusion or development of aneurysmal dilatation require interventional therapy.

OBJECTIVES

Presentation of different endovascular treatment options for complications of chronic type B aortic dissection.

MATERIALS AND METHODS

Analysis of current literature with regard to indications, techniques, results, and differential indications of interventional techniques for the treatment of chronic type B aortic dissection complications.

RESULTS

Endovascular implantation of an aortic stent graft is interventional standard therapy for treatment of aneurysmal dilatation of the aorta following type B dissection. Technical problems are the proximal and distal landing zones and the treatment of persistent flow in the false lumen.

CONCLUSION

Endovascular treatment of chronic complicated type B aortic dissection is increasingly used compared to open surgical treatment because not only are more complex stent grafts (fenestrated and branched devices) available but also because of newly developed techniques for effective occlusion of flow in the false lumen (e.g., candy plug).

Aortic remodeling after endovascular aortic repair and tailored distal entry tears exclusion in Crawford type III or IV dissection aneurysm

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) can only promote 55-80% false lumen (FL) thrombosis when only the proximal primary tear is covered during the repair of type B aortic dissection (TBAD). This study evaluated the effectiveness and clinical outcome of tailored exclusion of the primary entry tear with TEVAR and distal fenestrations with ancillary devices in patients with subacute or chronic Crawford type III and IV aortic dissection aneurysm.

METHODS

All patients underwent either TEVAR for primary entry tear; subsequently, various ancillary devices were applied on each distal fenestration. These techniques included covered stent occlusion of detached visceral artery entry tears, TL stenting and FL occlusion with vascular plugs in the common iliac artery dissection, or TEVAR coverage for multiple fenestrations from segmental arteries. This case series included nine patients (seven men and two women; mean age: 63.4 years) during January 2013 to May 2019. Outcome analysis included the rates of technical success and procedure-related complications, completeness of FL occlusion, aortic remodeling, and midterm mortality at 2 years.

RESULTS

The mean follow-up duration was 37.7 months without in-hospital mortality. One patient was lost to follow-up at the second month, the rest of patients were all alive during the follow-up period. All patients achieved complete FL thrombosis, and six patients exhibited aneurysm diameter shrinkage.

CONCLUSION

Tailored exclusion of visceral and iliac distal fenestrations with proximal primary tear coverage can promote FL thrombosis and aortic remodeling in the visceral aortic segment in patients with Crawford type III or IV aortic dissection aneurysm.

False lumen rotational flow and aortic stiffness are associated with aortic growth rate in patients with chronic aortic dissection of the descending aorta: a 4D flow cardiovascular magnetic resonance study

BACKGROUND

Patency of the false lumen in chronic aortic dissection (AD) is associated with aortic dilation and long-term aortic events. However, predictors of adverse outcomes in this population are limited. The aim of this study was to evaluate the relationship between aortic growth rate and false lumen flow dynamics and biomechanics in patients with chronic, patent AD.

METHODS

Patients with a chronic AD with patent false lumen in the descending aorta and no genetic connective tissue disorder underwent an imaging follow-up including a contrast-enhanced 4D flow cardiovascular magnetic resonance (CMR) protocol and two consecutive computed tomography angiograms (CTA) acquired at least 1 year apart. A comprehensive analysis of anatomical features (including thrombus quantification), and false lumen flow dynamics and biomechanics (pulse wave velocity) was performed.

RESULTS

Fifty-four consecutive patients with a chronic, patent false lumen in the descending aorta were included (35 surgically-treated type A AD with residual tear and 19 medically-treated type B AD). Median follow-up was 40 months. The in-plane rotational flow, pulse wave velocity and the percentage of thrombus in the false lumen were positively related to aortic growth rate (p = 0.006, 0.017, and 0.037, respectively), whereas wall shear stress showed a trend for a positive association (p = 0.060). These results were found irrespectively of the type of AD.

CONCLUSIONS

In patients with chronic AD and patent false lumen of the descending aorta, rotational flow, pulse wave velocity and wall shear stress are positively related to aortic growth rate, and should be implemented in the follow-up algorithm of these patients. Further prospective studies are needed to confirm if the assessment of these parameters helps to identify patients at higher risk of adverse clinical events.

Relationship of acute type A aortic dissection and disseminated intravascular coagulation

OBJECTIVE

Acute type A aortic dissection (ATAAD) is a critical disease presenting with disseminated intravascular coagulation (DIC). However, the relationship between the degree of DIC and false lumen conditions remains unclear. In the present study, we evaluated the degree of preoperative DIC and the outcomes of ATAAD treatment.

METHODS

A total of 124 patients with ATAAD (70 men and 54 women) treated from January 2012 to January 2020 were included in the present study. The correlation between the preoperative Japanese Association for Acute Medicine (JAAM) DIC score and the false lumen diameter and length, measured using preoperative computed tomography, was examined retrospectively. The correlations were calculated using liner regression analysis. The level of statistical significance was set at P < .05.

RESULTS

The patients were divided into two groups: a low JAAM DIC score group and a high JAAM DIC score group. The preoperative JAAM DIC scores in the high- and low-score groups were 4.8 ± 1.2 and 1.7 ± 2.3, respectively (P < .001). The 5-year survival rates and aortic event-free rates in the low-score group were favorable compared with the high-score group; however, the differences were not statistically significant (80.8% vs 54.5%, P = .065; 63.9% vs 59.8%, P = .15, respectively). The false lumen diameter in the ascending aorta was greater in the high-score group than that in the low-score group (P < .05). The JAAM DIC score correlated significantly with the ascending false lumen diameter and the dissection length (r = 0.32 and P < .001; r = 0.29 and P = .001, respectively). A high JAAM DIC score was associated with communicating-type ATAAD (P < .05).

CONCLUSIONS

Our results suggest that high preoperative JAAM DIC scores are associated with a large false lumen and communicating-type ATAAD.

Differences in the Area of Proximal and Distal Entry Tears at CT Angiography Predict Long-term Clinical Outcomes in Aortic Dissection

Purpose

To identify entry tear variables that are related to adverse clinical events by using CT angiography (CTA) performed during the subacute phase of aortic dissection.

Materials and Methods

In this prospective study conducted from January 2000 to December 2013, participants with an aortic dissection with a patent false lumen and no comorbidities underwent CTA during the subacute phase. Participants were followed up for a survival analysis to assess the time to an adverse aortic event (AAE). The maximum aortic diameter (MAD), proximal and distal tear areas and difference between these areas, and partial false-lumen thrombosis were assessed by using Cox regression for adverse events.

Results

Seventy-two participants (mean age, 55 years ± 12 [standard deviation]; 55 men) were evaluated: 47 were surgically treated (type A aortic dissection) and 25 were medically treated (type B aortic dissection). Twenty-two participants had an AAE manifest during follow-up (9.22 years ± 5.78): There were 18 elective surgeries for aneurysmal degeneration, two emergent surgeries for acute aortic syndrome, and two aortic condition-related deaths. A categorical model composed of genetic aortic disease (GAD) (hazard ratio [HR], 3.4 [95% CI: 1.2, 9.9]; P = .02), MAD greater than 45 mm (HR, 6.1 [95% CI: 2.4, 15.8]; P < .001), and tear dominance (HR, 5.2 [95% CI: 2.1, 13]; P < .001), defined as an absolute tear area difference of greater than 1.2 cm², was used to stratify participants into three risk groups: low, without any risk factors (57% [41 of 72] and 7% [three of 41] had events); intermediate, with one risk factor (31% [22 of 72] and 50% [11 of 22] had events); and high, with two or more risk factors (13% [nine of 72] and 89% [eight of nine] had events; log rank P < .001).

Conclusion

Tear dominance demonstrated at CTA performed in the subacute phase of aortic dissection was related to long-term adverse events. Participants without GAD, dominant tears, or MAD greater than 45 mm had conditions that were safely managed with optimal medical treatment and imaging follow-up.Keywords: CT Angiography, Vascular, Aorta, Dissection Supplemental material is available for this article. © RSNA, 2021See also commentary by Fleischmann and Burris in this issue.

Chronic thoracoabdominal aortic dissection: endovascular options to obliterate the false lumen

Background

Persistent false lumen patency in chronic thoracoabdominal aortic dissections after thoracic endovascular aortic repair (TEVAR) contributes to negative aortic remodeling. We have previously described the evolution of various endovascular techniques to treat persistent false lumen perfusion including false lumen embolization. Objectives of this study are to describe endovascular techniques to obliterate the false lumen and present updated outcomes in a recent series of patients undergoing false lumen embolization for chronic aortic dissection.

Methods

From January 2018 to May 2021, 17 patients with chronic dissection underwent false lumen embolization with coils, iliac plugs, and nitinol plugs. This was often in conjunction with or following TEVAR and balloon fracture fenestration. Mean follow-up 354±324 days.

Results

After false lumen embolization there was no mortality, stroke, spinal cord ischemia, or visceral and limb ischemia. No patients required dialysis, though 1 (5.9%) did experience acute kidney injury. There was 1 (5.9%) patient that required endovascular re-intervention on the thoracoabdominal aorta. No patients underwent subsequent open surgical repair.

Conclusions

TEVAR with adjunctive false lumen embolization and balloon fracture fenestration are techniques to obliterate retrograde flow into the false lumen of chronic thoracoabdominal aortic dissections in appropriately selected patients.

Obstructive Sleep Apnoea in Stanford Type B Aortic Dissection Is Associated With Multiple Imaging Signs Related to Late Aortic Events

Background: Obstructive sleep apnoea (OSA) is highly prevalent in patients with Stanford type B aortic dissection (TBAD). Few studies have evaluated the effects of OSA on vascular changes in TBAD patients. This study aimed to explore the effect of OSA on aortic morphological changes in TBAD patients and its relation to late aortic events (LAEs).

Methods: This case-control study included 143 TBAD patients. The diameters of different parts of the aorta were measured based on computed tomography angiography (CTA). According to the apnoea-hypopnoea index (AHI), OSA was classified as mild (5 ≤ AHI ≤ 15), moderate (15 < AHI ≤ 30), or severe (AHI > 30). The false lumen (FL) status was evaluated and classified as partially thrombosed, patent, or completely thrombosed.

Results: The OSA prevalence in TBAD patients was 64.3%, and image differences related to LAEs between TBAD patients with and without OSA included the maximum aortic diameter at onset (37.3 ± 3.9 vs. 40.3 ± 4.5 mm, p < 0.001), the FL diameter of the proximal descending thoracic aorta (16.0 ± 6.8 vs. 20.3 ± 4.7 mm, p < 0.001), and the proportion of the FL that was partially thrombosed (39.2 vs. 64.1%, p = 0.004). Additionally, in the multivariable analysis of patients with OSA, the risks of an aortic diameter ≥40 mm, a proximal descending aorta FL ≥ 22 mm and a partially thrombosed FL were 4.611 (95% CI: 1.796–11.838, p = 0.001), 2.544 (95% CI: 1.050–6.165, p = 0.039), and 2.565 (95% CI: 1.167–5.637, p = 0.019), respectively, after adjustment for confounding factors. Trend tests showed that the risks of an aortic diameter ≥40 mm and a partially thrombosed FL increased with increasing OSA severity.

Conclusions: TBAD patients with moderate to severe OSA have aortic dilatation in different parts of the aorta. OSA is an independent risk factor for multiple imaging signs related to LAEs, suggesting that OSA is an important factor affecting the prognosis of TBAD patients.

Influence of nocturnal hypoxemia on follow-up course after type B acute aortic syndrome

Introduction

Association between sleep nocturnal breathing disorders and acute aortic syndrome (AAS) has been described but mid-term data are scarce.

Objectives

We assessed the prognostic value of sleep apnea parameters and their relationship with aortic morphology after the onset of a type B AAS.

Methods

Between January 2010 and January 2018, sleep apnea screening in post type B AAS was prospectively performed. The association of sleep apnea parameters with aortic morphology and aortic expansion during follow-up was studied.

Results

Over the 8-year-study period, 103 patients were included, with a mean age of 57.8 ± 12.1 years old. Median follow-up was 25.0 months (11.0–51.0). Thirty-two patients (31%) required aortic stenting during the acute phase. In patients treated by aortic stenting, the descending thoracic aortic diameter was positively associated with a higher percentage of nocturnal time of saturation ≤ 90% after adjustment (p = 0.016). During follow-up, the nocturnal time of saturation ≤ 90% in patients treated by medical therapy was the only parameter associated with significant aortic expansion rate (r = 0.26, p = 0.04). Thirty-eight patients started and sustained nocturnal ventilation during follow-up. The association between aortic expansion rate and nocturnal time of saturation ≤ 90% did not persist during follow-up after adjustment on nocturnal ventilation initiation (r = 0.25, p = 0.056).

Conclusions

Nocturnal hypoxemia parameters are positively associated with the max onset aortic diameter and significant aortic growth after type B AAS. Nocturnal ventilation seems to mitigate aortic expansion during follow-up.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01778-y.

Similar Midterm Clinical Outcomes and Aortic Remodeling in Bifurcated and Straight Aortic Stent Grafts Used to Treat Isolated Abdominal Aortic Dissection

PURPOSE

The optimal treatment for isolated abdominal aortic dissection (IAAD) is currently unknown. We compared the effects of straight and bifurcated aortic stent grafts on postoperative aortic remodeling in patients with IAAD.

MATERIALS AND METHODS

From February 2012 to December 2019, 57 patients with IAAD were treated using endovascular methods, including either a bifurcated or a straight aortic stent graft. The clinical features, risk factors, computed tomography angiograms, midterm follow-up results, and aortic remodeling of these patients were reviewed and analyzed.

RESULTS

In total, 44 (77%) patients were treated with a bifurcated graft and 13 (23%) patients were treated with a straight graft. Patients treated with straight grafts had fewer common iliac arteries involved (38% vs 73%, p=0.023), the dissection length was shorter (76.3 ± 40.0 vs 116.2 ± 56.7 mm, p=0.011), and the preoperative aortic diameter (26.0 ± 5.6 vs 35.2 ± 12.1 mm) and the false lumen diameter (13.1 ± 5.2 vs 21.2 ± 11.3 mm) were smaller. During the procedure, there were 3 (5.3%) type I endoleaks, 1 (1.8%) surgical conversion and 1 (1.8%) partial renal artery coverage without perioperative mortality. Patients with straight grafts had shorter operative time (96.5 ± 24.4 vs 144.2 ± 49.0 minutes, p<0.0001). The median follow-up duration was 37.6 ± 21.0 (range = 3-89) months with 1 (1.8%) aortic-related death. Type A aortic dissection occurred in 1 (1.8%) patient. New descending aortic dissection occurred in 3 (5.3%) patients, and 1 patient advanced to type A aortic dissection 3 months later. Two (3.5%) patients had limb occlusion. There was no significant difference in aortic remodeling, survival, and freedom from all adverse events between the 2 treatment strategies.

CONCLUSIONS

Endovascular treatment provides a safe, minimally invasive treatment for IAAD in midterm follow-up. Compression of the true lumen at the aortic bifurcation is the main concern after treatment with a bifurcated graft. Straight grafts are an excellent alternative for some patients, with the benefit of reduced procedural time, effective aortic remodeling, and excellent clinical prognosis. More experience is needed to offer clear recommendations for making treatment decisions as well as determine long-term effectiveness and durability.

Mechanical characterization of dissected and dilated human ascending aorta using Fung-type hyperelastic models with pre-identified initial tangent moduli for low-stress distensibility

Ascending aortic dissection (AD) is a potentially fatal vascular disease associated with degradation and fragmentation of the elastic fibers in the aortic media, increasing low-stress distensibility, and a dilated aorta may lead to dissection. In this study, a Fung-type hyperelastic model was formulated incorporating the initial tangent moduli (ITM) of stress-strain curves as an index of low-stress distensibility. ITM were correlated with the material constants by linearizing incompressible stress-strain relationships at zero strain. For uniaxial loading tests, the robustness of the material constants was examined in the stress ranges of 0-200, 0-180, and 0-160 kPa and to the ITM values of 100%, 95%, and 90%. Examination revealed stable changes in the material constants of 80% of the specimens. For equibiaxial stretch tests, the material constants were determined for each curve of the isotropic and anisotropic deformation groups by pre-identifying the ITM and minimizing fitting errors using isotropic or anisotropic models. The errors for all groups were <6% using a transversely isotropic model, and <10% for an orthotropic model. Comparisons with experimental curves showed that Fung-type models described both the ITM and significant stiffening at high stress levels. The mechanical characteristics of the aorta in the stage prior/posterior to dissection is such that while hardening occurs under both low- and high-stress levels with an increase in collagen content as an aging response, softening occurs under low-stress conditions due to histological abnormalities such as elastin deficiency and fragmentation. Numerical simulations using Fung-type models implied that elastic fiber degeneration and fragmentation in AD tissues reduced not only the low-stress stiffness but also the elastic stiffness with superimposed shear. The latter stiffness was modulated by the stiffening at high stress levels in tensile deformation behavior and normal-strain state under physiological loading conditions, and therefore provides further insight into wall rupture.

Remodeling of Aortic Configuration and Abdominal Aortic Branch Perfusion After Endovascular Repair of Acute Type B Aortic Dissection: A Computed Tomographic Angiography Follow-Up

Background: Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) induces false lumen (FL) thrombosis, promotes favorable aortic remodeling, and makes an impact on abdominal aortic branch perfusion patterns. However, little is known about the long-term fate of aortic remodeling and abdominal aortic branch perfusion after TEVAR for TBAD and the effect of FL thrombosis status on these changes.

Materials and methods: Between January 2014 and May 2021, 59 enrolled patients with acute TBAD were treated with TEVAR and had post-operative or follow-up images. Pre-operative, post-operative, and latest follow-up CT angiography (CTA) data were analyzed for the largest diameter of true lumen (TL), FL, and transaorta and for the FL thrombosis status on the stented thoracic aorta, unstented thoracic aorta, and abdominal aorta. Abdominal aorta perfusion patterns were characterized.

Results: The mean follow-up period was 17.1 months. In the stented thoracic aorta, average TL diameters increased, average FL diameters decreased, and average transaortic diameters did not change; 82.6% of the patients had either a stable or shrinking transaortic size and 87% of the patients achieved total FL thrombosis. In the unstented thoracic aorta, average TL diameters increased, transaortic growth and no changes occurred in 39.1 and 45.7% of the patients, respectively, and complete FL thrombosis was present in 50% of the patients. In the abdominal aorta, average FL and transaortic diameters increased, aorta was expanded in 52.2% of the patients, and FL remained patent in 65.2% of the patients. Of the 354 branches, 37 branches (10.5%) exhibited changes in perfusion patterns, 22 branches (6.2%) demonstrated an increased TL perfusion, and 15 branches (4.2%) had an increased FL contribution. Compared with patent or partially thrombosed FL, complete FL thrombosis was accompanied by a bigger decrease in FL diameters, a larger increase in TL diameters, and a higher percentage of abdominal branch TL perfusion.

Conclusions: In majority of the patients, TEVAR stabilized the size of the stented thoracic aorta, namely TL expansion and FL obliteration. However, abdominal aortic FL remained patent FL, and it was expanded with the resultant transaortic growth over a long follow-up period. Abdominal aortic branch perfusion patterns remained largely stable after TEVAR. The failure to achieve FL thrombosis negatively affects the remodeling of a contagious abdominal aortic dissection.

En Bloc Arch Reconstruction With the Frozen Elephant Trunk Technique for Acute Type a Aortic Dissection

Objective: The study objective was to evaluate the effect of en bloc arch reconstruction with frozen elephant trunk (FET) technique for acute type A aortic dissection.

Methods: 41 patients with acute Stanford type A dissection underwent en bloc arch reconstruction combined with FET implantation between April 2018 and August 2020. The mean age of the patients was 46 ± 13 years, and 9 patients were female. One patient had Marfan syndrome. Six patients had pericardial tamponade, 9 had pleural effusion, 5 had transient cerebral ischemic attack, and 3 had chronic kidney disease.

Results: The hospital mortality rate was 9.8% (4 patients). 2 (4.9%) patients had stroke, 23 (56.1%) had acute kidney injury, and 5 (12.2%) had renal failure requiring hemodialysis. During follow-up, the rate of complete false lumen thrombosis was 91.6% (33/36) around the FET, 69.4% (25/36) at the diaphragmatic level, and 27.8% (10/36) at the superior mesenteric artery level. The true lumen diameter at the same three levels of the descending aorta increased significantly while the false lumen diameter reduced at the two levels: pulmonary bifurcation and the diaphragm. The 1-, 2-and 3-year actuarial survival rates were 90.2% [95% confidence interval (CI), 81.2–99.2], 84.2% (95% CI, 70.1–98.3) and 70.2% (95% CI, 42.2–98), respectively.

Conclusions: In patients with acute type A dissection, en bloc arch reconstruction with FET technique appeared to be feasible and effective with early clinical follow-up results. Future studies including a large sample size and long-term follow-up are required to evaluate the efficacy.

Outflow Through Aortic Side Branches Drives False Lumen Patency in Type B Aortic Dissection

Objective: Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) aims to induce false lumen (FL) thrombosis by sealing intimal tears between the true (TL) and the FL, and blocking the inflow into the FL. Incomplete thrombosis of the FL is correlated with poor clinical outcome. We hypothesize that the number of major and minor branches arising from the FL affects FL patency and may negatively influence TEVAR induced FL thrombosis.

Methods: Computed tomography (CT)-scans from 89 patients diagnosed with TBAD [best medical treatment (BMT) n = 52, TEVAR n = 37] from two high-volume vascular surgery centers were analyzed retrospectively. Analysis included evaluation of the FL patency status, the number, location and size of intimal tears, and the presence of minor and major side branches originating from the FL. Multiple regression analysis was conducted to evaluate obtained parameters as predictors for FL thrombosis status.

Results: In univariate analysis, the strongest correlation for FL patency was found for the number of major (R = 0.79) and minor (R = 0.86) side branches originating from the FL. When applying a multiple linear regression model, the number of major (normalized beta 0.37; P < 0.001) and minor (normalized beta 0.41; P < 0.01) side branches arising from the FL were valid predictors for the axial length of the patent and non-patent FL, and additionally determined the length of the patent FL at 12-month follow-up in patients that underwent TEVAR.

Conclusions: Our data suggest that the number of minor side branches that originate from the FL in TBAD is an important determinant of FL patency, to a greater degree than previously assumed.

Risk factors for incomplete thrombosis in false lumen in sub-acute type B aortic dissection post-TEVAR

There is scarce information about the risk factors for incomplete false lumen thrombosis (FLT) among type B aortic dissection (AD) patients, particularly in the sub-acute phase following thoracic endovascular aortic repair (TEVAR). We enrolled consecutive sub-acute type B AD patients at Xinqiao Hospital (Chongqing, China) from May 2010 to December 2019. Patients with severe heart failure, cancer, and myocardial infarction were excluded. The postoperative computed tomography angiography (CTA) data were extracted from the most recent follow-up aortic CTA. Multivariate logistic regressions were applied to identify the association between FLT and clinical or imaging factors. Fifty-five subjects were enrolled in our study. Twelve participants showed complete FLT, and 2 of these died during the follow-up, while 8 patients died in incomplete FLT group. In the multivariate analysis, maximum abdominal aorta diameter (OR 1.20, 95% CI 1.016-1.417 p = 0.032) and the number of branches arising from the false lumen (FL) (OR 15.062, 95% 1.681-134.982 p = 0.015) were significantly associated with incomplete FLT. The C-statistics was 0.873 (95% CI 0.773-0.972) for the model. The FL diameter (p < 0.001) was significantly shorter following TEVAR, while the true lumen diameter (p < 0.001) and maximum abdominal aorta diameter (p = 0.011) were larger after the aortic repair. There were 21.8% of sub-acute type B AD patients presented complete FLT post-TEVAR. Maximum abdominal aorta diameter and the number of branches arising from the FL were independent risk factors for incomplete FLT. The true lumen diameter, maximum abdominal aorta diameter, and FL diameter changed notably following TEVAR.

Targeting fenestrations in an aortic aneurysm secondary to chronic type A or B dissections: a case series

Using entry and re-entry analysis we report a simple technique designed to solely manage the fenestrations in an aortic aneurysm caused by chronic type A or B dissections. With meticulous computed tomography mapping of each fenestration, endovascular management can be customized to those areas only. Several cases are presented using this selective approach resulting in durable thrombosis of the false lumen. Targeted coverage of fenestrations in a chronic type B dissecting aneurysm is a feasible and effective management option resulting in reliable false lumen occlusion whilst maintaining visceral perfusion.

Amplatzer Vascular Plug for Complicated Residual DeBakey Type 1 Aortic Dissection in the Aortic Arch

Surgical treatment of acute DeBakey type I aortic dissection does not address the entire aorta, which can leave anatomically complex residual aortic dissection in the aortic arch and descending aorta. Open repair has been the standard treatment for this pathology. When the lesions are located in the aortic arch, re-do total arch replacement needs to be performed. Plug placement to close small entry tears in the aortic arch has been reported. This article reports about a 79-year-old man who underwent hemiarch replacement for acute DeBakey type I aortic dissection. One year later, his proximal descending aorta dilated to 6.3 cm. The patient was treated with Amplatzer plug in the false lumen, and a stent graft was placed in the true lumen. Follow-up computed tomography scan confirmed complete thrombosis of the false lumen in the descending aorta which had decreased from 6.3 to 4.0 cm. Plug placement in the false lumen in the aortic arch is a potential treatment strategy for anatomically complex residual aortic dissection to induce thrombosis of the false lumen and encourage remodeling.

The short-term prognostic value of serum platelet to hemoglobin in patients with type A acute aortic dissection

PURPOSE

Type A acute aortic dissection (AAD) is an uncommon catastrophic cardiovascular disease with high pre-hospital mortality rate without timely and effectively treated. The aim of this study was to assess the value of serum platelet to hemoglobin (PHR) in predicting in-hospital mortality in type A AAD patients.

METHODS

A total of 183 type A AAD patients were included in this retrospective investigation from January 2017 to December 2019. Admission blood routine parameters were gathered and PHR was computed. The outcome was all-cause in-hospital mortality within 30 days.

RESULTS

The average levels of serum PHR were significant higher in survivor group than those in non-survivor group (1.14 ± 0.57 vs 0.87 ± 0.47, p = 0.006) and serum PHR was an independent factor associated with in-hospital mortality (hazard ratio (HR): 2.831; 95% confidence interval (CI): 1.108-7.231; p = 0.030). ROC noted that 0.8723 was chosen as the ideal cutoff value with a sensitivity of 64.3% and specificity of 72.5%. In addition, the area under the ROC curve (AUC) was 0.693 (95% CI 0.599-0.787, p < 0.001).

CONCLUSION

Admission serum PHR can be used as an independent predictor of in-hospital mortality in patients with type A AAD.

Role of Endoluminal Techniques in the Management of Chronic Type B Aortic Dissection

In recent guidelines of international societies, the most frequent indication for treatment after chronic type B aortic dissection (cTBAD) is aneurysmal dilatation. Endovascular repair is recommended in patients with moderate to high surgical risk or with contraindications to open repair. During the last decade, many advances have been made in the field of endovascular techniques and devices. The aim of this article is to address the current status of endoluminal techniques for the management of cTBAD including standard thoracic endovascular repair, new devices, fenestrated and branched abdominal aortic devices and false lumen occlusion techniques.

Long-term outcomes of the frozen elephant trunk procedure: a systematic review

Background

The frozen elephant trunk (FET) procedure remains an increasingly popular approach to address complex multi-segmental aortic pathologies, owing to their ability to promote false lumen thrombosis and reduce the need for second-stage operations. While the short-term outcomes of such procedures have been shown to be acceptable, much less is known regarding long-term outcomes. This systematic review evaluates long-term outcomes of the FET procedure.

Methods

Studies with at least 12 months follow-up data on FETs were identified in four electronic databases. All studies were reviewed by two independent researchers and relevant data extracted. Long-term outcomes, including overall survival, freedom from reintervention, and freedom from aortic events, were evaluated using patient data recreated from digitized Kaplan-Meier curves.

Results

Thirty-seven studies with 4,178 patients were identified. The majority of the studies focused solely on acute dissections. Average follow-up was 3.2 years. Overall survival at 1-, 3-, and 5-year was 89.6%, 85.2%, and 82.0%, respectively. Freedom from reintervention at the same timepoints were 93.9%, 89.3%, and 86.8%, respectively. Mortality, permanent neurological deficit and spinal cord injury were 10.2%, 7.7%, and 6.5%, respectively.

Conclusions

Survival after the FET procedure is favorable, though ongoing close serial monitoring is essential to assess for the need for further reintervention. Larger multi-institutional registries are required to provide more robust evidence to better elucidate the patient cohort that would most benefit from the FET.

A meta-analysis of combined proximal stent grafting with or without adjunctive distal bare stent for the management of aortic dissection

BACKGROUND

The efficacy and safety of placement of a proximal covered stent graft combined with a distal bare stent are controversial because of the lack of evidence. This systematic review and meta-analysis compared the outcomes of combined proximal covered stent grafting with distal bare stenting (BS group) and proximal covered stent grafting without distal bare stenting (non-BS group).

METHODS

The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases and key references were searched up to January 26, 2019. Predefined outcomes of interest were mortality, morbidity, and postoperative assessment of aortic remodeling. We pooled risk ratios (RRs) of the outcomes of interest using fixed effects model or random effects model.

RESULTS

Overall, eight observational studies involving 914 patients were included. There were no significant differences in overall aorta-related mortality (RR, 0.54; confidence interval [CI], 0.24-1.24; P = .15), complete thoracic false lumen (FL) thrombosis rate (RR, 1.23; CI, 0.83-1.81; P = .30), or complete abdominal FL thrombosis rate (RR, 1.96; CI, 0.68-5.69; P = .21) between the BS group and the non-BS group. The BS group had a lower rate of partial thoracic FL thrombosis (RR, 0.40; CI, 0.25-0.65; P = .0002), a lower stent graft-induced new entry rate (RR, 0.08; CI, 0.02-0.41; P = .003), and a lower reintervention rate (RR, 0.42; CI, 0.26-0.69; P = .0005).

CONCLUSIONS

Combined proximal covered stent grafting with distal adjunctive bare stenting had the potential to reduce the partial thoracic FL thrombosis rate and the rates of stent graft-induced new entry and reintervention but was not associated with lower aorta-related mortality or the complete FL thrombosis rate. Further research with a stricter methodology is needed.

Aortic morphology post type A acute aortic syndrome: Prognosis significance and association with 24-hour blood pressure-monitoring parameters

BACKGROUND

After an emergent surgery for type A acute aortic syndrome, medical management is based on optimal blood pressure (BP) control. We assessed the prognostic significance of BP monitoring and its relationship with aortic morphology following type A acute aortic syndrome.

METHODS

The data of 120 patients who underwent BP monitoring after a type A acute aortic syndrome from January 2005 to June 2016 were retrospectively collected. The first CT angiogram performed after surgery was used for the morphological analysis.

RESULTS

The population included 79 males, with an overall mean age of 60 ± 12 years. Seven patients (5.8%) died during a median follow-up of 5.5 years. The median delay between BP monitoring and discharge was 3 (1-5) months. The mean 24-hour BP of the cohort was 127/73 mm Hg ± 10/17. During follow-up, different parameters of BP monitoring were not associated with the risk of aortic events. However, the diameter of the false lumen of the descending thoracic aorta was the best predictor associated with the risk of new aortic events during follow-up, particularly for the threshold of 28 mm or more (P < .001; Hazard ratio 4.7[2.7-8.2]). The diameter of the false lumen was associated with night-time systolic BP (P = .025; r = .2), 24-hour pulse pressure (P = .002; r = .28), and night-time pulse pressure (P = .008; r = .24).

CONCLUSION

The risk of new aortic events following type A acute aortic syndrome is associated with the size of the residual false lumen, but not directly with BP parameters. Night-time BP parameters are associated with the size of the residual false lumen.

Staged Fenestrated/Branched Repair of Postdissecting Thoracoabdominal Aneurysm With Candy-Plug False Lumen Occlusion for Spinal Cord Preconditioning

Purpose: To describe a possible application of thoracic false lumen occlusion techniques with a Candy-Plug occluder to induce false lumen thrombosis for preconditioning the spinal cord during staged fenestrated repair of postdissecting thoracoabdominal aneurysms. Technique: A Candy-Plug occluder is deployed within the thoracic false lumen after proximal entry tear coverage with a standard thoracic stent-graft during staged repair of postdissecting thoracoabdominal aneurysms. The blockade of thoracic false lumen retrograde reperfusion from distal entry tears induces a controlled thrombosis of both the thoracic false lumen and intercostal arteries. Then, when the fenestrated device is delivered 4 to 6 weeks later, the procedure is completed with standard techniques according to the staging protocols of individual centers. Conclusion: A new possible application of a Candy-Plug false lumen occlusion technique might be an intermediate procedure aimed at preconditioning the spinal cord by occluding the thoracic false lumen during complex staged fenestrated thoracoabdominal repairs.

Device profile of the Zenith Dissection Endovascular System for aortic dissection

Introduction: Thoracic endovascular aortic repair has been increasingly used to treat type B aortic dissection (TBAD) when it is indicated, offering better outcome in terms of mortality and morbidity compared to open repair. Accepted goals for endovascular treatment of aortic dissections are the closure of the primary intimal entry tear, depressurization, and thrombosis of the false lumen. Areas covered: This is a descriptive review on the Zenith Dissection Endovascular System (Cook Medical Inc., Bloomington, IN) which is a modular system specifically designed to treat TBAD, consisting of a proximal component, the Zenith TX2 TAA Endovascular Graft, and a distal component, the Zenith Dissection Endovascular Stent. The distal stents are uncovered to avoid blockage of dominant spinal cord intercostal arteries and allow for the deployment of the stents across branch vessel origins as needed to treat the dissection. Expert opinion: The Zenith Dissection Endovascular System has already been used for the treatment of TBAD for the last decade mostly in experienced centers. Current evidence suggests that this is a feasible and safe technique with relative low early mortality and morbidity rates. It is important to highlight the potential benefit of Zenith Dissection Endovascular System on the remodeling the dissected aorta during the follow-up period.

Single Low-Volume Center Experience with Frozen Elephant Trunk in Acute Type A Aortic Dissections

BACKGROUND

 Acute Type A aortic dissection (AAAD) is a surgical emergency. In patients with arch and descending aorta involvement (DeBakey Type I), a total aortic arch replacement with frozen elephant trunk (FET) could favor false lumen thrombosis and improve long-term results. The authors hereby present their experience with this technique in a single low-volume center, to assess whether the technique is feasible to treat such disease.

METHODS

 From January 2011 to December 2016, 43 patients with AAAD were operated on in the authors' institution, which carries out 300 to 350 annual procedures. Among these, 12 patients with an intimal tear in the aortic arch and/or proximal descending aorta received a FET procedure (10 males, age 57 years). Concomitant procedures were aortic valve replacement (42%), Bentall (25%), and aortic valve repair (17%).

RESULTS

 Cardiopulmonary bypass, cardiac arrest, and circulatory arrest times were 235 ± 43, 171 ± 33, and 75 ± 20 minutes, respectively. The operative mortality was 16.7% (n = 2). Stroke and re-thoracotomy for bleeding occurred in 8% (n = 1) and 8% (n = 1), respectively. There was no spinal cord injury. Follow-up was 36.1 months. During follow-up, no patients died or required a reoperation on the downstream aorta.

CONCLUSION

 Although all patients were operated on in a low-volume center, the results with FET in AAAD are acceptable. Even though this technique demands high technical skills, it is a promising approach in patients with acute aortic dissection.

False lumen embolization in chronic aortic dissection promotes thoracic aortic remodeling at midterm follow-up

OBJECTIVE

Failure of thoracic endovascular aortic repair (TEVAR) in chronic aortic dissections can be partially explained by retrograde false lumen (FL) flow through distal re-entry tears. After implantation of a thoracic stent graft, FL thrombosis occurs in less than 50% of the cases. The objectives of this study were to describe the feasibility and outcomes of FL embolization in patients with chronic aortic dissections.

METHODS

Between June 2015 and January 2018, 27 patients (mean age, 61 ± 14 years) with chronic aortic dissection underwent FL embolization as an adjunct during or after TEVAR placement procedure. Indications for embolization were (1) symptomatic chronic aortic dissections with pain or rapid growth of aortic diameter (≥5 mm/y) requiring rapid exclusion of the aneurysm, (2) aneurysmal dilatation with persistent FL retrograde flow after TEVAR, and (3) large FL aneurysms (≥55 mm) that might lead to persistent retrograde flow. Twenty patients presented with type B chronic aortic dissections (74.1%) and seven presented a residual type A chronic aortic dissections (25.9%). Eight patients had a previous aortic arch replacement (29.6%). Six patients had previous repair with TEVAR (22.2%). The delay between the onset of dissection and the first endovascular repair was 47 months (range, 3-144). Spinal fluid drainage was used in 74.1% of cases (20/27 patients). Embolization devices included coils and vascular plugs.

RESULTS

The technical success rate was 100% (27/27). Complete spinal cord ischemia was observed in one patient (3.7%). There was one hospital death from pneumonia after zone 1 supra-aortic trunk debranching with TEVAR and embolization. After the index procedure, FL thrombosis was observed in 81.5% of patients (22/27) on late phase computed tomography angiography. Five patients required two or more embolization procedures, leading to a high rate of complete FL thrombosis (92.6%). One patient presented a type IB endoleak and one patient presented a type II endoleak. Radiologic follow-up was 20 ± 10 months. The maximum thoracic aortic diameter significantly decreased from 63 mm to 54 ± 10 mm (P < .001).

CONCLUSIONS

Embolization of the FL of chronic aortic dissections is technically feasible with a low morbidity rate. The FL thrombosis is observed in the majority of case and promotes favorable thoracic aortic remodeling. Longer follow-up is needed to confirm these good results on the thoracic aorta and this technique may, therefore, improve the results of TEVAR in chronic aortic dissections.