Volume analysis of true and false lumens in acute complicated type B aortic dissections after thoracic endovascular aortic repair with stent grafts alone or with a composite device design

Long-Term Volumetric Evaluation of Stent-Assisted Balloon-Induced Intimal Disruption and Relamination of Aortic Dissection (STABILISE) in Acute Type B Aortic Dissection

BACKGROUND

To quantify the volumetric aortic remodeling of patients with acute type B aortic dissection treated with the stent-assisted balloon-induced intimal disruption and relamination (STABILISE) technique.

METHODS

All patients with acute type B aortic dissection operated with the STABILISE technique between 2014 and 2017 with preoperative, postoperative, and >12 months (follow-up) computed tomography scans were included in this study. True lumen and total aortic volume were accurately assessed in the thoracic and abdominal portions with a semiautomatic three-dimensional tool. Associations with long-term adverse events were estimated.

RESULTS

Seventeen patients were measured at preoperative, postoperative, and a mean follow-up of 19 ± 8 months. The false lumen to total volume ratio decreased on average from 63% to 18% after STABILISE (P < 0.001) and remained around 12% at follow-up. These remodeling was more pronounced in the thoracic aorta (7%) than in the abdominal aorta (28%). The trend in aortic size growth was stronger for volumes than for maximum areas or diameters (P < 0.001, P < 0.05, and P < 0.05, respectively). Adverse events were identified in 4 patients during a long-term follow-up of 76 ± 18 months. The only aortic size variable assessed preoperatively that was associated with undesirable events was the total volume of the abdominal aorta (P < 0.05).

CONCLUSIONS

A volumetric analysis of dissected aortic size after the STABILISE procedure allowed accurate quantification of mid-term aortic remodeling and helped to identify the abdominal aortic volume as a preoperative variable associated with undesirable long-term events.

Factors associated with false lumen changes in patients with superior mesenteric artery dissection

BACKGROUND

False lumen changes (FLCs) are the main reference for the prognosis judgment and treatment plan selection for type IIa superior mesenteric artery dissection (SMAD).

METHODS

For this retrospective study, 55 patients with symptomatic type IIa SMAD were included. Computational fluid dynamics (CFD) analysis was used to explore the hemodynamic basis of FLCs. Correlation and multiple linear regression analyses were performed to identify clinical, morphological and hemodynamic factors associated with FLCs.

RESULTS

The FLCs of patients with successful conservative treatment (n = 29) are significantly higher than those with failed conservative treatment (n = 26) (58.5 ± 21.1% vs 10.9 ± 17.4%, p < 0.0001). Positive correlations were seen between FLCs and the morphological parameters false lumen length (FLL)/dissection entrance length (DEL) and FLL. In terms of hemodynamic parameters, negative correlations were seen between FLCs and time-averaged wall shear stress (TAWSS), vorticity, and high areas of TAWSS and vorticity, whereas positive correlations were seen between FLCs and oscillatory shear index (OSI), relative residence time (RRT), and high areas of OSI and RRT. Multiple linear regression analysis identified symptom duration (odds ratio [OR], 0.93; 95% CI, 0.91-0.96; p < 0.0001), FLL/DEL (OR, 1.30; 95% CI, 1.01-1.67; p = 0.044), and high RRT area (OR, 2.03; 95% CI, 1.48-2.78; p < 0.0001) as predictors of FLCs.

CONCLUSION

The clinical predictor symptom duration, morphological factor FLL/DEL, and the hemodynamic factor high RRT area can serve as predictors of FLCs in patients with symptomatic type IIa SMAD.

Volumetric analysis in primary and residual type B aortic dissection treated with stented-assisted balloon-induced intimal disruption and relamination technique can predict aortic reintervention

OBJECTIVE

The aim of this study was to investigate the mid-term results of stented-assisted balloon-induced intimal disruption and relamination (STABILISE) in patients with aortic dissection with the implementation of volumetric analysis.

METHODS

This was a single-center retrospective analysis of prospectively collected data. From May 2017 to September 2022, 42 patients underwent STABILISE for acute complicated or subacute high-risk aortic dissection. STABILISE was completed with distal extended endovascular aortic repair in 24 patients. A computed tomography scan was performed at baseline, before hospital discharge, and at 1, 3, and 5 years. Perfused total aortic, true lumen, and false lumen volumes were assessed for thoracic, visceral, and aorto-iliac segment. The ratio between false lumen and total volume was named perfusion dissection index (PDI). Complete remodeling was defined as PDI = 0, and positive remodeling as PDI ≤0.1.

RESULTS

Technical success was 97.6%. No 30-day deaths, spinal cord injuries, or retrograde dissections were observed. Mean follow-up was 44 ± 19.4 months. Thoracic diameter was lower at last available computed tomography scan (36.7 vs 33.0 mm; P = .01). Aortic growth >5 mm was observed in 9.5% of the patients. Thoracic and visceral aortic complete remodeling were 92.8% and 83.3%, respectively, with no difference between acute and subacute group. Distal extended endovascular aortic repair significantly increased complete remodeling in the aorto-iliac segment, compared with STABILISE alone (69.6% vs 21.4%; P < .001). Freedom from vascular reinterventions at 3 years was 83.1% (95% confidence interval, 71.5%-96.6%). Total PDI ≤0.1 at first postoperative control was a predictor of vascular reinterventions (P < .0001).

CONCLUSIONS

STABILISE is a safe and feasible technique associated with high mid-term rates of complete remodeling in the thoracic and visceral aorta. Volumetric analysis allows the quantification of aortic remodeling and represents a predictor of aortic reinterventions.

Risk Factors for Incomplete Aortic Remodeling With Stent-Assisted Balloon-Induced Intimal Disruption and Relamination in Aortic Dissection Repair for Complicated Aortic Dissection: Results of a Multicenter Study

PURPOSE

The STABILISE technique has extended the treatment of aortic dissection to the thoracoabdominal aorta to achieve complete aortic remodeling. The aim of this multicenter study was to analyze the short- and midterm anatomical results of the STABILISE technique.

MATERIALS AND METHODS

We retrospectively analyzed patients treated with the STABILISE technique for complicated aortic dissection at 3 French academic centers. The aortic diameter at different levels was measured preoperatively, postoperatively, and at 1 year.

RESULTS

Between 2018 and 2020, 58 patients, including 47 men (average patient age: 60±11 years), were treated for type B aortic dissection in 34 cases and residual aortic dissection after type A repair in 24 cases. Three (5.2%) patients died postoperatively. Complete aortic remodeling (false lumen thrombosis and complete reapposition of the intimal flap) was achieved in 45/55 patients (81.8%), and false lumen thrombosis in the thoracic aorta was achieved in 52/55 patients (94.5%). At 1 year, with a computed tomographic (CT) scan available for 98.2% (54/55) of patients, we observed a significant decrease in the maximal thoracic aortic diameter and a significant increase in the aortic diameter at the bare-stent level compared with the preoperative CT scan. Severe aortic angulation (p=0.024) was a risk factor for incomplete aortic remodeling and significantly increased the aortic diameter (p=0.032). Chronic aortic dissection was associated with an increased risk of incomplete aortic remodeling (p=0.002).

CONCLUSIONS

STABILISE for complicated aortic dissection results in false lumen thrombosis, complete reapposition of the intimal flap, and a decrease in the maximum aortic diameter in most cases. Incomplete reapposition of the intimal flap, which is more frequent in cases of chronic aortic dissection and severe aortic angulation, is a risk factor for a significant increase in the aortic diameter at the bare-stent level, and this risk justifies close follow-up and better patient selection.

CLINICAL IMPACT

STABILISE technique for complicated aortic dissection results in false lumen thrombosis, complete aortic remodeling and a decrease in the maximum aortic diameter in most cases. At the bare-stent level, incomplete reapposition of the intimal flap, more frequent in chronic aortic dissection and severe aortic angulation, is a risk factor for an increased aortic diameter. This finding justifies close follow-up and better patient selection; thus, the STABILISE technique should be used with care in chronic aortic dissection and severe aortic angulation.

Deep learning-based multi-stage postoperative type-b aortic dissection segmentation using global-local fusion learning

Objective.Type-b aortic dissection (AD) is a life-threatening cardiovascular disease and the primary treatment is thoracic endovascular aortic repair (TEVAR). Due to the lack of a rapid and accurate segmentation technique, the patient-specific postoperative AD model is unavailable in clinical practice, resulting in impracticable 3D morphological and hemodynamic analyses during TEVAR assessment. This work aims to construct a deep learning-based segmentation framework for postoperative type-b AD.Approach.The segmentation is performed in a two-stage manner. A multi-class segmentation of the contrast-enhanced aorta, thrombus (TH), and branch vessels (BV) is achieved in the first stage based on the cropped image patches. True lumen (TL) and false lumen (FL) are extracted from a straightened image containing the entire aorta in the second stage. A global-local fusion learning mechanism is designed to improve the segmentation of TH and BR by compensating for the missing contextual features of the cropped images in the first stage.Results.The experiments are conducted on a multi-center dataset comprising 133 patients with 306 follow-up images. Our framework achieves the state-of-the-art dice similarity coefficient (DSC) of 0.962, 0.921, 0.811, and 0.884 for TL, FL, TH, and BV, respectively. The global-local fusion learning mechanism increases the DSC of TH and BV by 2.3% (p< 0.05) and 1.4% (p< 0.05), respectively, based on the baseline. Segmenting TH in stage 1 can achieve significantly better DSC for FL (0.921 ± 0.055 versus 0.857 ± 0.220,p< 0.01) and TH (0.811 ± 0.137 versus 0.797 ± 0.146,p< 0.05) than in stage 2. Our framework supports more accurate vascular volume quantifications compared with previous segmentation model, especially for the patients with enlarged TH+FL after TEVAR, and shows good generalizability to different hospital settings.Significance.Our framework can quickly provide accurate patient-specific AD models, supporting the clinical practice of 3D morphological and hemodynamic analyses for quantitative and more comprehensive patient-specific TEVAR assessments.

In Marfan Syndrome and Related Diseases, STABILISE Technique Should Be Used with Care: Results from a Volumetric Comparative Study of Endovascular Treatment for Aortic Dissection

Objectives: Aortic dissection in patients with Marfan and related syndromes (HTAD) is a serious pathology whose treatment by thoracic endovascular repair (TEVAR) is still under debate. The aim of this study was to assess the results of the TEVAR for aortic dissection in patients with HTAD as compared to a young population without HTAD. Methods: The study received the proper ethical oversight. We performed an observational exposed (confirmed HTAD) vs. non-exposed (<65 years old) study of TEVAR-treated patients. The preoperative, 1 year, and last available CT scans were analyzed. The thoracic and abdominal aortic diameters, aortic length, and volumes were measured. The entry tears and false lumen (FL) status were assessed. The demographic, clinical, and anatomic data were collected during the follow-up. Results: Between 2011 and 2021, 17 patients were included in the HTAD group and 22 in the non-HTAD group. At 1 year, the whole aortic volume increased by +21.2% in the HTAD group and by +0.2% the non-HTAD groups, p = 0.005. An increase in the whole aortic volume > 10% was observed in ten cases (58.8%) in the HTAD group and in five cases (22.7%) in the non-HTAD group (p = 0.022). FL thrombosis was achieved in nine cases (52.9%) in the HTAD group vs. twenty (90.9%) cases in the non-HTAD group (p < 0.01). The risk factors for unfavorable anatomical evolution were male gender and the STABILISE technique. With a linear model, we observed a significantly different aortic volume evolution between the two groups (p < 0.01) with the STABILISE technique; this statistical difference was not found in the TEVAR subgroup. In the HTAD patients, there was a significant difference in the total aortic volume evolution progression between the patients treated with the STABILISE technique and the patients treated with TEVAR (+160.1 ± 52.3% vs. +47 ± 22.5%, p < 0.01 and +189.5 ± 92.5% vs. +58.6 ± 34.8%, p < 0.01 at 1 year and at the end of follow-up, respectively). Conclusions: TEVAR in the HTAD patients seemed to be associated with poorer anatomical outcomes at 1 year. This result was strongly related to the STABILISE technique which should be considered with care in these specific patients.

Potential biomarkers of aortic dissection based on expression network analysis

Background

Aortic dissection (AD) is a rare disease with severe morbidity and high mortality. Presently, the pathogenesis of aortic dissection is still not completely clear, and studying its pathogenesis will have important clinical significance.

Methods

We downloaded 28 samples from the Gene Expression Omnibus (GEO) database (Accession numbers: GSE147026 and GSE190635), including 14 aortic dissection samples and 14 healthy controls (HC) samples. The Limma package was used to screen differentially expressed genes. The StarBasev2.0 tool was used to predict the upstream molecular circRNA of the selected miRNAs, and Cytoscape software was used to process the obtained data. STRING database was used to analyze the interacting protein pairs of differentially expressed genes under medium filtration conditions. The R package "org.hs.eg.db" was used for functional enrichment analysis.

Results

Two hundred genes associated with aortic dissection were screened. Functional enrichment analysis was performed based on these 200 genes. At the same time, 2720 paired miRNAs were predicted based on these 200 genes, among which hsa-miR-650, hsa-miR-625-5p, hsa-miR-491-5p and hsa-miR-760 paired mRNAs were the most. Based on these four miRNAs, 7106 pairs of circRNAs were predicted to be paired with them. The genes most related to these four miRNAs were screened from 200 differentially expressed genes (CDH2, AKT1, WNT5A, ADRB2, GNAI1, GNAI2, HGF, MCAM, DKK2, ISL1).

Conclusions

The study demonstrates that miRNA-associated circRNA-mRNA networks are altered in AD, implying that miRNA may play a crucial role in regulating the onset and progression of AD. It may become a potential biomarker for the diagnosis and treatment of AD.

Balloon Inducted Re-Lamination and False lUmen Thrombosis in Chronic Type B Aortic Dissection: Technique and Long-Term Results

BACKGROUND

To evaluate the safety, feasibility, and effectiveness of the BAlloon Inducted re-Lamination and false lUmen Thrombosis (BAILOUT) as a simple technique to address the retrograde false lumen (FL) perfusion and subsequent aneurysmatic degeneration of the thoracic aorta due to a stent-graft crimped in a small true lumen in chronic Type B dissections.

METHODS

An observational, retrospective, single-center study analyzing a nonconsecutive cohort of 8 patients affected by chronic type B aortic dissections already treated with thoracic endovascular repair and with an FL lumen backflow corrected with BAILOUT between 2006 and 2020. After a standard distal extension of the previously implanted graft, the distal end of the graft area was ballooned to completely rupture the dissection lamella to relaminate the aorta hindering the FL backflow. Computed tomography was routinely performed within the first postoperative week before discharge and then at 3 months, at 6 months, and yearly thereafter. The technical and clinical success rates were analyzed. Primary outcomes were safety and feasibility of the technique, secondary ones included FL thrombosis evaluation, and total aortic diameter analysis at the above-defined levels during the follow-up. Safety was defined if clinical success was reached. Feasibility was intended as technical success obtention.

RESULTS

The technical and clinical success achieved was 100% with the complete interruption of FL backflow stating the safety and feasibility of the BAILOUT technique. No early procedure reinterventions were recorded and during a median follow-up of 62.5 months [interquartile range 43.2-94.1], only 1 death unrelated to the procedure was recorded. Freedom from aortic-related adverse events at 1 month, 3 months, 1 year, 5, and 7 years was 87.5%, 62.5%, 62.5%, 62.5%, and 62.5%, respectively. During the follow-up, no one increment of the diameter of the thoracic aorta was documented and all the patients at 3 years of computed tomography angiography showed a complete FL thrombosis.

CONCLUSIONS

The BAILOUT technique demonstrates to be safe and feasible in this small cohort of patients as a simple and quick way to overcome the issue of FL backflow in chronic type B dissection. Small cohort and retrospective designs were limitations of the study.

Volume Analysis to Predict the Long-Term Evolution of Residual Aortic Dissection after Type A Repair

Background: The aim of this study was to evaluate the aortic diameter and volume during the first year after a type A repair to predict the long-term prognosis of a residual aortic dissection (RAD). Methods: All patients treated in our center for an acute type A dissection with a RAD and follow-up > 3 years were included. We defined two groups: group 1 with dissection-related events (defined as an aneurysmal evolution, distal reintervention, or aortic-related death) and group 2 without dissection-related events. The aortic diameters and volume analysis were evaluated on three postoperative CT scans: pre-discharge (T1), 3−6 months (T2) and 1 year (T3). Results: Between 2009 and 2016, 54 patients were included. Following a mean follow-up of 75.4 months (SD 31.5), the rate of dissection-related events was 62.9% (34/54). The total aortic diameters of the descending thoracic aorta were greater in group 1 at T1, T2 and T3, with greater diameters in the FL (p < 0.01). The aortic diameter evolution at 3 months was not predictive of long-term dissection-related events. The total thoracic aortic volume was significantly greater in group 1 at T1 (p < 0.01), T2 (p < 0.01), and T3 (p < 0.01). At 3 months, the increase in the FL volume was significantly greater in group 1 (p < 0.01) and was predictive for long-term dissection-related events. Conclusion: This study shows that an initial CT scan volume analysis coupled with another at 3 months is predictive for the long-term evolution in a RAD. Based on this finding, more aggressive treatment could be given at an earlier stage.

Fate and Consequences of the False Lumen after TEVAR in Type B Aortic Dissection

BACKGROUND

Type B aortic dissection (TBAD) occurs due to an entry tear in the intimal layer of the aorta distal to the origin of the left subclavian artery where blood enters the newly formed false lumen (FL) and extends distally or proximally to form a dissection over an indeterminate length of the aorta which, over time, may eventually rupture. Thoracic endovascular aortic repair (TEVAR) aims to seal off the entry tear proximally with the stent-graft, occluding the origin of the dissection and excluding the FL. Nevertheless, in some cases, the perfusion to the FL is maintained, hindering the aortic remodelling process and increasing the risk of aneurysmal degeneration and rupture, particularly in the abdominal aorta where evidence suggest that remodelling is slower. This review examines the long-term effects of a patent or partially thrombosed FL on clinical outcomes following TEVAR in TBAD, also highlighting the pathological processes behind negative aortic remodelling. Another aim of this review is to provide an overview and appraisal of the currently available techniques for managing a patent or partially thrombosed FL to prevent long-term morbidity occurring.

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

Evidence in the literature show that a partially thrombosed FL is more dangerous than a patent FL due to the occlusion of the distal re-entry tears, impeding outflow and increasing mean arterial and diastolic pressures, whereas the latter is decompressed via distal re-entry sites. FL thrombosis and satisfactory remodelling is sometimes achieved in as few as 40% of patients after TEVAR due to the maintained perfusion of the FL either at the level of the thoracic or abdominal aorta. However, although the thoracic aorta is predominantly covered by the TEVAR stent-graft, poorer remodelling and more dilation is seen in the abdominal aorta. Several techniques are available to embolize the FL, including the Provisional Extension to Induce Complete Attachment, Stent Assisted Balloon Induced Intimal Disruption and Relamination in Aortic Dissection Repair, candy-plug, and Knickerbocker techniques.

CONCLUSIONS

The management of TBAD is invariably TEVAR to seal off the proximal entry tear while extending the repair distally to completely exclude the FL. A risk of aortic wall dilatation distal to TEVAR stent-graft remains; hence, regular monitoring and accurate imaging are essential. At present, a patent FL can be treated using a range of different endovascular techniques.

Five-year results of the STABLE II study for the endovascular treatment of complicated, acute type B aortic dissection with a composite device design

OBJECTIVE

To provide the five-year outcomes of the use of a composite device (proximal covered stent-graft + distal bare stent) for endovascular repair of patients with acute, type B aortic dissection complicated by aortic rupture and/or malperfusion.

METHODS

STABLE II was a prospective, multicenter study of the Zenith Dissection Endovascular System (William Cook Europe, Denmark). Patients were enrolled between August 2012 and January 2015 at sites in the United States and Japan. Five-year follow-up was completed by January 2020.

RESULTS

In total, 73 patients (mean age 60.7±10.9 years; 65.8% male) with acute type B dissection complicated by malperfusion (72.6%), rupture (21.9%), or both (5.5%) were enrolled. Patients were treated with either a composite device (79.5%) or the proximal stent-graft alone (no distal bare stent, 20.5%). Dissections were more extensive in patients who received the composite device (408.9±121.3 mm) than in patients who did not receive a bare stent (315.9±100.1 mm). Mean follow-up was 1209.4±754.6 days. Freedom from all-cause mortality was 80.3%±4.7% at one year and 68.9%± 7.3% at five years. Freedom from dissection-related mortality remained at 97.1%±2.1% from one-year through five-year follow-up. Within the stent-graft region, the rate of either complete thrombosis or elimination of the false lumen increased over time (82.1% of all patients at five years vs. 55.7% at first post-procedure CT), with a higher rate at five years in patients who received the composite device (90.5%) compared with patients without the bare stent (57.1%). Throughout follow-up, overall true lumen diameter increased within the stent-graft region, and overall false lumen diameter decreased. At five years, 20.7% of patients experienced a decrease in maximum transaortic diameter within the stent-graft region, 17.2% experienced an increase, and 62.1% experienced no change. Distal to the treated segment (but within the dissected aorta), 23.1% of patients experience no change in transaortic diameter at five years; a bare stent was deployed in all these patients at the procedure. Five-year freedom from all secondary intervention was 70.7%±7.2%.

CONCLUSIONS

These five-year outcomes indicate a low rate of dissection-related mortality for the Zenith Dissection Endovascular System in the treatment of patients with acute, complicated type B aortic dissection. Further, these data suggest a positive influence of composite device use on false lumen thrombosis. Continuous monitoring for distal aortic growth is necessary in all patients.

Initial Study of the Extended STABILISE Technique for Complete Remodeling in Aortic Dissection

OBJECTIVES

Thoracic endovascular aortic repair (TEVAR) is the standard treatment for acute complicated type B aortic dissection (TBAD). However, long-term results reveal that TEVAR does not achieve a complete aortic remodeling and poses a risk of aneurysmal aortic degeneration. Distal reentry treatment at the abdominal level seems to be necessary to obtain a complete remodeling in TBAD. Moreover, it is necessary to treat the aortoiliac bifurcation in patients with persistent true lumen collapse or limb ischemia.

METHODS

Between January 2018 and October 2019, 11 patients with acute or sub-acute complicated TBAD or non-A non-B aortic dissection were treated in our institution in an endovascular fashion. We performed the stent-assisted balloon-induced intimal disruption and relamination in aortic dissection repair (STABLISE) technique in all cases, but two cases required complementary treatment of the aortoiliac bifurcation with a bifurcated AFX endograft system for limb ischemia due to true lumen collapse.

RESULTS

Technical success was obtained in all patients. No procedural complications occurred. No postoperative deaths, stroke, paraplegia, mesenteric, or renal ischemia were observed, and no secondary intervention was necessary. Satisfactory aortic remodeling was obtained after the follow-up periods with a 57.5% mean true lumen expansion.

CONCLUSION

Our initial experience using the extended STABILISE (e-STABILISE) technique using a bifurcated AFX endograft did not result in any postoperative mortality or complications. Without additional data, this technique should be reserved for specific patients who require revascularization of the aortoiliac bifurcation.

The STABILISE technique to address malperfusion on acute-subacute type B aortic dissections

Endovascular treatment is the current standard of care for complicated acute and subacute type B aortic dissection. Closure of the primary entry tear with thoracic endovascular aneurysm repair (TEVAR) is often insufficient to induce complete false lumen thrombosis and a positive aortic remodeling. Moreover, TEVAR does not solve all the cases of malperfusion. The Provisional ExTension to Induce COmplete ATtachment (PETTICOAT) technique (deploying self-expandable bare metal stents in the true lumen in addition to TEVAR) can re-expand the true lumen, stabilize the lamella and promote aortic remodeling, but it does not recreate a single-lumen aorta and long-term aneurysmal degeneration of the aorta is frequent. Endovascular treatment by means of TEVAR + PETTICOAT does not recreate a single-lumen aorta so long-term aneurysmal degeneration of the aorta is frequent. The stent-assisted, balloon-induced intimal disruption and relamination of aortic dissection (STABILISE) technique may help to this purpose disrupting the intimal lamella and creating a relaminated uni-luminal aorta.

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.

Clinical Results and Aortic Remodeling After Endovascular Treatment for Complicated Type B Aortic Dissection With the “Fabulous” Stent System

Objective

To report the clinical outcomes and aortic remodeling after the implantation of a self-developed, biomechanically optimized, two-stage thoracic stent system named Fabulous.

Background

Given the efficacy of the PETTICOAT concept, the benefits of Fabulous and the behavior of remodeling in different segments need further investigation.

Methods

This is a prospective and multicenter study. From 2017 to 2019, 145 patients (mean age, 56.6 years; 88.3% male) from 14 centers were included in this cohort. The clinical results and core laboratory results were from a central electronic data capture system. Computed tomographic angiography was performed preoperatively, 1 month, 6 months and yearly thereafter and was used for volumetric analysis by 3mensio (Bilthoven, The Netherlands). After the 1-year follow-up, 97.2 and 87.6% of the clinical and imaging results of the eligible patients were available.

Results

Both stent grafts and bare stents were successfully delivered in place in 100% of the patients. The 30-day mortality and 1-year freedom from all-cause mortality were 2.1 and 96.6%, respectively. The incidence of entry flow was 11.7% at 30 days and 6.2% at 365 days. No cases of stent-induced new entry (SINE) or reintervention were observed. After the 1-year follow-up, the true lumen/overall volume ratio reached 88%. The following subdivided segment volume changes were recorded: stent graft segment TL +56%; FL −92%, bare stent segment TL +32%; FL −75%, and there were no significant changes in the visceral segment.

Conclusions

These outcomes indicated that there were favorable clinical benefits of Fabulous stent system. This device achieved a low short-term mortality and a low incidence of reintervention. In addition, patients undergoing Fabulous stent system implantation showed remodeling both on descending aorta and on the distal aorta. The volume changes in the TL and FL varied in the different segments. The long-term follow-up is still ongoing.

Unexpected Bare Metal Stent Migration Associated With Aortic Remodeling After PETTICOAT Technique for Aortic Dissection

PURPOSE

To report a unique case of bare metal stent migration in the overlapping zone and subsequent distal stent graft-induced new entry (SINE) after the Provisional Extension to Induce a Complete Attachment (PETTICOAT) technique for aortic dissection.

CASE REPORT

A 67-year-old man underwent thoracic endovascular aortic repair (TEVAR) using the PETTICOAT technique for acute complicated type B aortic dissection. The postoperative course was uneventful, and follow-up computed tomography (CT) showed not only favorable aortic remodeling but also progressive bare metal stent migration in the overlapping zone between the stent graft and the bare metal stent. A 6-month postoperative CT revealed a distal SINE, and the patient underwent re-TEVAR to cover the new entry. Postoperative CT demonstrated successful repair of the distal SINE. The patient is currently in good health 2 years after the reintervention.

CONCLUSION

Surgeons should consider the potential risk of device migration due to favorable aortic remodeling after TEVAR for aortic dissection, especially with the use of additional bare metal stents.

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.

Fate of the Dissected Thoraco-Abdominal Aorta Distal to TEVAR (Thoracic Endovascular Aortic Repair) for Complicated Acute and Subacute Type B Aortic Dissection

PURPOSE

This study assessed morphological changes in the aortic true and false lumens during follow-up of patients undergoing TEVAR (Thoracic Endovascular Aortic Repair) for complicated acute and subacute type B dissection. The study analyzes the effectiveness of TEVAR in preventing distal aneurysmal progression.

MATERIALS AND METHODS

All patients between 2009 and 2019 undergoing TEVAR for complicated acute and subacute type B dissection at the study institution were retrospectively reviewed. Maximal diameters were measured on the proximal descending aorta right below the left subclavian artery, thoraco-abdominal junction right above the celiac trunk, and infrarenal aortic right above the inferior mesenteric artery, pre-operatively and during follow-up, analyzing either expansion or shrinkage of true and false lumens at these 3 sites.

RESULTS

Forty-one patients were included. Thirty-day incidence of death, stroke, paraplegia, and visceral ischemia was, respectively, 8% (n = 4), 6% (n = 3), 2% (n = 1), and 2% (n = 1). Three patients (6%) died from intervention-related cause. Mortality was 17% (n = 8) during a mean follow-up of 54 months. One patient had aneurysmal dilation of the descending aorta needing additional coverage and only 2 (4%) developed thoraco-abdominal aneurysms requiring re-intervention. In the remaining patients, both significant expansion of the true lumen and shrinkage of false lumen were observed at all 3 sites.

CONCLUSION

Proximal coverage of the main entry tear appears to prevent aneurysmal progression in most patients (96%). With such promising results, TEVAR should be considered as a first-line treatment in acute and subacute type B dissection.

Endovascular repair of acute complicated type B aortic dissection-systematic review and meta-analysis of long-term survival and reintervention

Background

Thoracic endovascular repair (TEVAR) is considered the first-line therapy in the repair of acute complicated type B aortic dissection (AC-BAD). Given the difficulty of designing randomized trials in this surgical cohort, long-term outcome data is limited. This systematic review and meta-analysis provide a complete aggregation of reported long-term survival and freedom from reintervention of AC-BAD patients based on the existing literature.

Methods

Three databases were searched from date of database inception to January 2021. The relevant references were identified and baseline cohort characteristics, survival and freedom from reintervention were extracted. The primary endpoints were survival and freedom from reintervention, whilst secondary endpoints were post-operative outcomes such as cord ischemia and endoleak. Kaplan-Meier curves were digitized and aggregated as per established procedure.

Results

A total of 2,812 references were identified in the literature search for review, with 46 selected for inclusion. A total of 2,565 patients were identified, of which 1,920 (75%) were male. The mean age of the cohort was 59.8±5.8. Actuarial survival at 2, 4, 6 and 10 years was 87.5%, 83.2%, 78.5% and 69.7%, respectively. Freedom from all secondary reintervention at 2, 4, 6, 8 and 10 years was 74.7%, 69.1%, 65.7%, 63.9% and 60.9%, respectively. When accounting for study quality, actuarial survival at 2, 4, 6 and 8 years was 85.4%, 79.1%, 69.8% and 63.1%, respectively. Freedom from all secondary reintervention at 2, 4, 6 and 8 years was 73.2%, 67.6%, 63.7% (maintained), respectively.

Conclusions

TEVAR is associated with promising long-term survival extended to 10 years, though rates of freedom from reintervention remain an ongoing point for improvement. Randomized controlled trials comparing endovascular with open repair in the setting of acute, complicated type B aortic dissection are needed.

Numerical simulation flow dynamics of an intracranial aneurysm

BACKGROUND

Computational fluid dynamics provides a new method for the study of the blood flow characteristics of the formation and development of intracranial aneurysms.

OBJECTIVE

To compare blood flow characteristics between the healthy internal carotid artery and normal intracranial aneurysms.

METHODS

The internal carotid arteries were simulated to obtain hemodynamic parameters in one patient.

RESULTS

The internal carotid artery associated with aneurysm presents low wall shear stress, high oscillatory shear index, and high particle retention time compared with the normal internal carotid artery.

CONCLUSIONS

There are differences in blood flow between the normal internal carotid artery and intracranial aneurysm. The vortex of the aneurysm will produce turbulence, indicating that it is unstable, which results in the growth and rupture of the aneurysm.

Thoracic Endovascular Aortic Repair With Additional Distal Bare Stents in Type B Aortic Dissection Does Not Prevent Long-Term Aneurysmal Degeneration

PURPOSE

TEVAR (thoracic endovascular aortic repair) + PETTICOAT (Provisional ExTension to Induce COmplete ATtachment) technique has been selectively employed since 2005 at our institution during endovascular treatment of type B aortic dissection (TBD). The aim of this study is to evaluate the long-term (>5 years) clinical results and the evolution of aortic volume.

MATERIALS AND METHODS

All the patients receiving an endovascular treatment for TBD with the PETTICOAT technique were collected in a prospectively maintained database and follow-up computed tomography scan were retrospectively analyzed. Study endpoints included short- and long-term clinical success (absence of need for reintervention) and any major adverse event. The volumes of thoracic and abdominal aorta at long-term follow-up were also analyzed.

RESULTS

Twenty-eight patients received a TEVAR + PETTICOAT and were followed up (median follow-up 85 months). Primary 30-day clinical success rate was 82% with an adverse event rate of 31%; 4 type I endoleak and 1 retrograde dissection were recorded. Secondary mid-term clinical success was 96% while the long-term clinical success rate was 79%. Six cases (21%) received either an open repair or an endovascular repair for a significant distal aortic enlargement at follow-up. With regards to volumetric analysis, an increase of overall (thoracic and abdominal) aortic volume was observed in 8 cases mainly related to an increase (mean: +31%) of the abdominal volume that was observed in 11 cases.

CONCLUSIONS

PETTICOAT technique does not protect from long-term significant aneurysmal degeneration that may require aortic open or endovascular reinterventions. Aortic growth occurs mainly in the bare-stented aorta and thus, life-long surveillance is advisable in these patients.

Technique-Based Evaluation of Clinical Outcomes and Aortic Remodelling Following TEVAR in Acute and Subacute Type B Aortic Dissection

INTRODUCTION

To evaluate the clinical outcomes and aortic remodelling rates following thoracic endovascular aortic repair (TEVAR) for acute or subacute type B aortic dissection (TBAD) based on technique.

MATERIAL AND METHODS

All TEVARs for acute/subacute TBAD between 01/01/2008 and 01/06/2020 were included. TEVARS were grouped by technique (TEVAR only, PETTICOAT and STABILISE). Aortic remodelling was assessed at three aortic levels on follow-up CT. Thirty-day technical/clinical success rates, re-intervention rates and complications were recorded.

RESULTS

A total of 29 patients were included. The median age was 55 years (31-82). The median duration from initial presentation to TEVAR was 7 days (0-84). Intra-procedural complications included one aortic rupture from balloon moulding in a STABILISE case. Thirty-day mortality, stroke, spinal cord ischaemia and visceral ischaemia were 3% (n = 1), 3% (n = 1), 3% (n = 1) and 3% (n = 1), respectively. (All occurred in acute TBAD.) Overall survival was 50.5 months (18-115). Median follow-up was 31 months (1-115). Six patients (21%) required re-intervention, with a median time of 5 months (5-46) from first TEVAR. Overall complete aortic remodelling rates were: 89% at the proximal descending thoracic aorta, 78% at the distal thoracic aorta and 50% at the infra-renal abdominal aorta. At the infra-renal aorta, the STABILISE group (n = 11) had a higher complete aortic remodelling rate (82%) compared to TEVAR alone (n = 12) (20%).

CONCLUSION

Endovascular intervention for acute and subacute TBAD is safe with a high rate of technical success. STABILISE results in higher aortic remodelling at the infra-renal aorta (82%) compared to TEVAR alone (20%) but risks aortic rupture from balloon moulding.

Complicated acute type B aortic dissection: update on management and results

BACKGROUND

The role of thoracic endovascular aortic repair (TEVAR) has evolved and is now firmly established as a mainstay of therapy for acute complicated type B aortic dissection (acTBAD). However, several important issues remain unresolved including the optimal timing, sizing, graft selection, coverage length and utilization of adjunctive therapies to address false lumen perfusion. Therefore, the purpose of this study was to provide a contemporary perspective on the management and results for TEVAR of acTBAD.

METHODS

All TEVAR patients (N.=159) with acTBAD from a single high-volume, academic medical center were analyzed. Comparative results across time-dependent cohorts (2005-2009 [N.=43] vs. 2010-2014 [N.=56] vs. 2015-2020 [N.=60]) are presented.

RESULTS

30-day mortality was 13%(N.=21) with a trend towards improvement over time (2005-2009, 18% vs. 2010-2020, 12%; P=0.1). Similarly, incidence of postoperative complications also declined: 2005-2009, 70% vs. 2010-2020, 36%(P-trend=0.08). One and 2-year freedom from aorta-related reintervention was 78±7% and 73±9% and did not differ across cohorts (log-rank P=0.5). Respective one and 5-year survival was 75±3% and 64±7%, but significantly improved with time (log-rank P<0.001). The corresponding one and five-year freedom from aorta-related mortality was 82±4% and 78±7% but did not change during the study interval (log-rank P=0.3).

CONCLUSIONS

Outcomes for TEVAR of acTBAD continue to improve over time. This time-dependent analysis delineates how results have changed due to increasing experience, technologic evolution, and maturation of the peer reviewed evidence. These results along with the evidence-based review provided herein, provide an update on the management and results of TEVAR of acTBAD while highlighting specific controversies unique to the management of this challenging clinical problem.

Satisfactory Long-term Outcomes of Thoracic Endovascular Aortic Repair With a Bare Stent for Acute Complicated Type B Aortic Dissections

PURPOSE

To compare the clinical outcomes after thoracic endovascular aortic repair (TEVAR) with a bare stent to those after TEVAR alone in patients with complicated acute type B aortic dissection (cATBAD).

MATERIALS AND METHODS

A prospective, randomized trial was conducted at 2 medical centers in China between 2010 and 2013. Patients with cATBAD were randomly assigned to receive TEVAR with a bare stent (n=42) or TEVAR only (n=42). Patients were scheduled to undergo computed tomography angiography at 3, 6, and 12 months and then annually to 5 years. The primary endpoint was all-cause mortality at 5 years; secondary outcomes were a composite of complications (endoleak, stent-graft-induced new entry, aortic rupture, and secondary intervention) and aortic remodeling at 1 and 5 years.

RESULTS

All-cause death occurred in 1 (2.4%) patient in the TEVAR with bare stent group (lung cancer) and 5 patients (11.9%) in the TEVAR group (4 aorta-related) during the 5-year follow-up (log-rank p=0.025). The 1- and 5-year rates of complications and secondary interventions did not differ between the groups. Patients in the TEVAR with bare stent group had higher increases in the thoracic true lumen diameter (19.7±3.6 vs 17.0±6.2 mm, p=0.018) and abdominal true lumen diameter (13.7±4.8 vs 7.2±6.1 mm, p<0.001) and a higher incidence of complete false lumen thrombosis (80.9% vs 47.6%, p=0.005) at the 1-year follow-up. However, no between-group differences in the changes of aortic remodeling parameters were observed between the 1- and 5-year follow-up periods.

CONCLUSION

The addition of a distal bare stent to a thoracic stent-graft during TEVAR was associated with significantly improved long-term survival in cATBAD patients vs TEVAR only, likely due to the prevention of true lumen collapse and improvement of complete false lumen thrombosis of the dissected aorta.

Distal bare metal stent implantation during thoracic endovascular aortic repair is beneficial to treat complicated type B aortic dissection: A systematic review and meta-analysis

OBJECTIVE

To explore whether thoracic endovascular aortic repair (TEVAR) plus distal bare metal stent (BMS) implantation leads to favorable clinical outcomes compared with standard TEVAR in treating acute complicated type B aortic dissection.

METHODS

Relevant publications were found through a precise search of PubMed, Cochrane Library, and EMBASE. Count data were calculated as the odd ratio (OR)and 95% confidence interval (CI) using the Mantel-Haenszel statistical method, quantitative data were calculated as mean difference and 95% CI using Inverse Variance statistical method. When the data heterogeneity was large, with an I² > 50%, a random-effects model and sensitivity analysis were performed. The analysis tool we used was the software Revman 5.3 and G*power 3.1.

RESULTS

There were 7 publications involving 958 patients who were enrolled ultimately. The incidence of unplanned secondary intervention and postoperative adverse events in the TEVAR + BMS were lower than standard TEVAR (OR, 0.42, (95% CI, 0.23 to 0.75); OR, 0.57, (95% CI, 0.37 to 0.90)), and the pooled number needed to treat was 15 for unplanned secondary intervention and 15 for postoperative adverse events. There were no significant difference in the aortic-related or all-cause 30-day mortality (OR, 0.81, (95% CI, 0.25 to 2.61); OR, 0.47, (95% CI, 0.18 to 1.22)), aortic-related, all-cause mortality at least 6 months or incidence of the postoperative endoleak (OR, 0.47, (95% CI, 0.17 to 1.32); OR, 0.42, (95% CI, 0.17 to 1.06); OR, 0.81, (95% CI, 0.32 to 2.05)).

CONCLUSION

There is no significant outcome difference except for reduced reintervention but this does not seem to adversely affect survival. It is unclear whether this justifies the additional cost of placing it in every complicated type B aortic dissection regardless of anatomy after standard TEVAR alone. Besides, more data are needed to verify the adjunctive distal bare metal stents' performance at different dissection stages.

Endovascular strategies for post-dissection aortic aneurysm (PDAA)

Residual patent false lumen (FL) after type B aortic dissection (TBAD) repair is independently associated with poor long-term survival. Open surgery and endovascular repair result in good clinical outcomes in patients with AD. However, both treatments focus on proximal dissection but not distal dissection. About 13.4–62.5% of these patients present with different degrees of distal aneurysmal dilatation after primary repair. Although open surgery is the first-choice treatment for post-dissection aortic aneurysm (PDAA), there is a need for high technical demand since open surgery is associated with high mortality and morbidity. As a treatment strategy with minimal invasion, endovascular repair shows early benefits and low morbidity. For PDAA, the narrow true lumen (TL), rigid initial flap and branch arteries originating from FL have increased difficulties in operation. The aim of endovascular treatment is to promote FL thrombosis and aortic remodeling. Endovascular repair includes intervention from FL and TL sides. TL intervention techniques (parallel stent-graft, branched and fenestrated stent-graft among others) have been proven to be safe and effective in PDAA. Other FL intervention techniques that have been used in selected patients include FL embolization and candy-plug techniques. This article introduces available endovascular techniques and their outcomes for the treatment of PDAA.

Twelve-Month Computed Tomography Follow-Up after Thoracic Endovascular Repair for Acute Complicated Aortic Dissection

BACKGROUND

To explore the impact of thoracic endovascular aortic repair (TEVAR) on aortic remodeling (AR) and the relationship between AR and complications after TEVAR.

METHODS

A total of 56 patients (2 type IIIA aortic dissection [AD] and 54 type IIIB AD) with complicated acute type B aortic dissection suitable for TEVAR were prospectively enrolled. There were 44 men (78%) and 12 women (22%) with an average age of 54 ± 13.8 years. Aortic enhanced computed tomography (CT) was performed pre-TEVAR and 3, 6, and 12 months postoperatively. The morphological changes in AR, namely aortic volume and false lumen thrombosis, were obtained by analyzing the CT data. The effect of TEVAR on AR was determined by the morphological changes in the aorta. The relationship between AR index, false lumen thrombosis, and complications was analyzed.

RESULTS

The volume of the thoracic aortic true lumen gradually increased post-TEVAR, whereas the volume of the thoracic aortic false lumen gradually decreased. The volume of abdominal aortic total lumen and false lumen increased 6 months postoperatively. The AR index increased significantly 3 months postoperatively, which was negatively correlated with complications and mortality. The thoracic and abdominal aortic false lumen thrombosis developed gradually after TEVAR, and the degree of thoracic aortic false lumen thrombosis was negatively correlated with complications and mortality.

CONCLUSIONS

TEVAR promotes AR. AR index and the degree of thoracic aortic false lumen thrombosis can serve as predictors of complications and mortality.

One-Year Single-Center Results of the Multilayer Flow Modulator Stents for the Treatment of Type B Aortic Dissection

Purpose

To report a single-center series of patients with type B aortic dissection treated with the Multilayer Flow Modulator (MFM).

Materials and Methods

Over a 36-month period, 23 patients (median age 53 years; 20 men) with complicated type B aortic dissections (2 acute, 5 subacute, and 16 chronic) were treated with the MFM. Primary endpoints of rupture or dissection-related death, overall mortality, and reintervention were evaluated using the Kaplan-Meier method; estimates for freedom from the endpoints are reported with the 95% confidence interval (CI). Secondary outcomes included technical success, adverse events, and aortic remodeling. Clinical and imaging data were collected preoperatively, directly postoperatively, and annually to 36 months for analysis using computational fluid dynamics (CFD).

Results

Initial technical success was 91.3%. The estimates of the endpoints at 12 months were 100% for freedom from rupture or aortic-related death, 95.7% for freedom from overall mortality, and 91.3% for freedom from reintervention. No device-related neurological or systemic complications occurred, and no additional reinterventions were needed during follow-up. A total of 144 branches overstented by the MFM remained patent. Morphologic analysis of the aortic dissection showed progressive true lumen volume increase (75.9%, p<0.001) with concomitant false lumen volume decrease (42.8%, p<0.001); the CFD analyses showed increased laminar flow.

Conclusion

In the current series, the MFM provided a safe and feasible treatment option for complicated acute, subacute, and chronic type B aortic dissections, with high technical success, low mortality, and active aortic remodeling. Further studies should elucidate the long-term safety of the MFM and its effectiveness in a larger patient cohort.

Preclinical evaluation of an endovascular sealing device for distal re-entry tears in type B aortic dissection in a porcine model

OBJECTIVES

The objective of present study was to evaluate the feasibility and safety of a novel endovascular sealing device for distal re-entry tears in type B aortic dissection in a porcine model.

BACKGROUND

Distal re-entry tears are a well-recognized risk factor for unfavorable aortic remodeling after thoracic endovascular aortic repair. However, there is currently no device for sealing a distal re-entry tear.

METHODS

We implanted the ENDOPATCH device (Weiqiang Medical, Hangzhou, China) in 15 pigs (40-50 kg) under angiographic guidance. The device can be retrieved and repositioned with an 8-10 French sheath. All pigs were assessed using angiography before sacrifice 1- (n = 1), 3- (n = 1), and 6 months (n = 13) after implantation, which was followed by gross specimen evaluation and histological examination of harvested tissues.

RESULTS

The ENDOPATCH device was successfully implanted in all 15 pigs. The mean disk diameter of the implant was 10.3 ± 1.7 mm, and the chosen device was 4.4 ± 0.9 mm larger than the measured maximum diameter of the fistula. No device migration or leakage was observed angiographically, before sacrifice. An organized thrombus on the disk surface was found in the inferior vena cava of one pig. Complete sealing of the fistula was confirmed by gross and microscopic examinations in all pigs.

CONCLUSIONS

Our results indicated that the ENDOPATCH device is feasible and safe in a porcine model. Human studies are needed to evaluate the safety and efficacy of the ENDOPATCH.

Geometric Analysis of Type B Aortic Dissections Shows Aortic Remodeling After Intervention Using Multilayer Stents

Recently, multilayer stents for type B aortic dissections (TBAD) have been proposed to decrease false lumen flow, increase and streamline true lumen flow, and retain branch vessel patency. We aimed to provide a protocol with standardized techniques to investigate aortic remodeling of TBAD by multilayer flow modulators (MFM) in static geometric and hemodynamic analyses. Combining existing literature and new insights, a standardized protocol was designed. Using pre- and postoperative CT scans, geometric models were constructed, lumen dimensions were calculated, computational fluid dynamics (CFD) models were composed, and velocity and pressures were calculated. Sixteen TBAD cases treated with MFM were included for analysis. For each case, aortic remodeling was analyzed using post-processing medical imaging software. After 3D models were created, geometrical anatomical measurements were performed, and meshes for finite element analysis were generated. MFM cases were compared pre- and postoperatively; true lumen volumes increased (p < 0.001), false lumen volumes decreased (p = 0.001), true lumen diameter at the plane of maximum compression (PMC) increased (p < 0.001), and false lumen index decreased (p = 0.008). True lumen flow was streamlined, and the overall fluid velocity and pressures decreased (p < 0.001 and p = 0.006, respectively). This protocol provided a standardized method to evaluate the effects of MFM treatments in TBAD on geometric analyses, PMC, and CFD outcomes.

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.

Improved Remodeling With TEVAR and Distal Bare-Metal Stent in Acute Complicated Type B Dissection

BACKGROUND

The ASSIST (A multicentre Study in Survivors of type B aortic dissection undergoing Stenting) study compared both 1-year outcomes and evolution of true and false lumen (eg, remodeling) in patients with complicated type B aortic dissection subjected to thoracic endovascular aortic repair (TEVAR) with distal true lumen scaffolding by self-expanding nitinol open stent in comparison with TEVAR alone.

METHODS

The ASSIST study was a multicenter prospective single-arm study comparing clinical and imaging data from 39 consecutive patients (59.4 ± 13 years of age) who received TEVAR and the JOTEC E-XL open stent with data from matched control subjects treated with TEVAR alone based on 1:1 propensity score matching. Clinical data were collected by an independent Contract Research Organization (CRO) and computed tomography images were subjected to blinded core-lab analysis.

RESULTS

There were no differences in baseline demographics, clinical profiles, morphological data, procedural details, and in-hospital and 1-year outcomes between groups. Differences emerged with regard to evolution of both true lumen distal to stent graft, false lumen over the entire length of dissection, and remodeling (P < .001). At 1 year, TEVAR with the E-XL stent revealed false lumen thrombosis at the level of celiac trunk in 53.8% vs 17.9% with TEVAR alone (P = .004). Kaplan-Meier survival analysis indicated favorable clinical outcomes with the additional E-XL stent.

CONCLUSIONS

TEVAR for acute complicated type B aortic dissection proved to be safe and promoted remodeling of the stent grafted thoracic aorta. Additional scaffolding of the true lumen distal to TEVAR with a self-expanding stent supported distal true lumen expansion, false lumen regression, and thrombosis, with evidence of improved distal remodeling at 1 year.

Association Between Extent of Stent-Graft Coverage and Thoracic Aortic Remodeling After Endovascular Repair of Type B Aortic Dissection

Purpose: To examine the association between the extent of stent-graft coverage and thoracic aortic expansion after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection. Materials and Methods: A retrospective analysis was conducted of 201 patients (mean age 52.4±11.5 years; 178 men) with acute (135, 67.2%) or chronic (66, 32.8%) type B aortic dissection who underwent TEVAR at 4 medical centers. The mean stent-graft length was 157.1±33.3 mm. The percentage of stented descending aorta (PSDA) represented the extent of stent-graft coverage. After using restricted cubic smoothing spline plots to confirm the roughly linear relationship between PSDA and the risk of thoracic aortic expansion, patients were stratified into 2 groups on the median PSDA: the lower group (≤31.3%) and the higher group (>31.3%). Thoracic aortic expansion was defined as a ≥20% increase in the total thoracic aortic volume on the most recent postoperative computed tomography angiography scan compared with the preoperative measurement. The Kaplan-Meier method was used to estimate the cumulative freedom from thoracic aortic expansion after TEVAR; estimates are given with the 95% confidence interval (CI). A multivariable Cox proportional hazards model was used to analyze any independent association of the PSDA as a continuous or categorical variable with the risk of thoracic aortic expansion; results are presented as the hazard ratio (HR) and 95% CI. Results: No patients developed symptoms of spinal cord ischemia during hospitalization. Over a median 12.4 months of imaging follow-up, 34 (16.9%) patients developed thoracic aortic expansion. The estimate of freedom from thoracic aortic expansion at 12 months for the overall PSDA was 84.0% (95% CI 77.8% to 88.6%); between the groups, the freedom from thoracic aortic expansion estimate for the PSDA ≤31.3% group was significantly lower than in the higher group (p=0.032). Regression analysis showed no significant association between the risk of thoracic aortic expansion and the PSDA as a continuous variable (HR 0.97, 95% CI 0.91 to 1.03, p=0.288); however, analyzing the PSDA as a categorical variable indicated a significantly lower risk of thoracic aortic expansion for the PSDA >31.3% group (HR 0.46, 95% CI 0.22 to 0.95, p=0.036) after adjusting for a variety of demographic and anatomical characteristics. Conclusion: More extensive stent-graft coverage appears to improve thoracic aortic remodeling after TEVAR. However, the clinician should balance the benefit of extensive stent-graft coverage and its related risk of spinal cord ischemia.

Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) Reporting Standards for Type B Aortic Dissections

This Society for Vascular Surgery/Society of Thoracic Surgeons (SVS/STS) document illustrates and defines the overall nomenclature associated with type B aortic dissection. The contents describe a new classification system for practical use and reporting that includes the aortic arch. Chronicity of aortic dissection is also defined along with nomenclature in patients with prior aortic repair and other aortic pathologic processes, such as intramural hematoma and penetrating atherosclerotic ulcer. Complicated vs uncomplicated dissections are clearly defined with a new high-risk grouping that will undoubtedly grow in reporting and controversy. Follow-up criteria are also discussed with nomenclature for false lumen status in addition to measurement criteria and definitions of aortic remodeling. Overall, the document provides a facile framework of language that will allow more granular discussions and reporting of aortic dissection in the future.

Combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair for complicated type B aortic dissections

BACKGROUND

Aortic dissection is a separation of the aortic wall, caused by blood flowing through a tear in the inner layer of the aorta. Aortic dissection is an infrequent but life-threatening condition. The incidence of aortic dissection is 3 to 6 per 10,000 per year in the Western population, and can be up to 43 per 10,000 per year in the Eastern population. Over 20% of people with an aortic dissection do not reach a hospital alive. After admission, the mortality rates for people with an aortic dissection are between 10% and 20% for those who received endovascular treatment, and between 20% and 30% for those who had open surgery. Thoracic endovascular aortic repair (TEVAR) is the standard endovascular method to treat complicated type B aortic dissection (aortic dissections without involvement of the ascending aorta). Although TEVAR is less invasive than open surgery and has a better long-term aortic remodeling effect than conservative medical treatment, favourable aortic remodelling is usually limited to the thoracic aortic segment. TEVAR cannot be extended into the abdominal aorta because it could cover the ostia of the reno-visceral arteries. Thus, the abdominal aorta is still at risk of progressive aneurysmal degeneration. The PETTICOAT (provisional extension to induce complete attachment) technique, with proximal endograft and distal bare metal stent, was proposed in 2006 to address this issue. The concept of this technique was to implant a distal bare metal stent into the aortic true lumen, distal to the proximal endograft, to stabilize the distal collapsed intimal flap, while allowing blood flow to reno-visceral arteries. Therefore, the PETTICOAT technique was considered to be related to a more extensive aortic remodelling for people with type B aortic dissection, especially in the area of the abdominal aorta. However, it is still unclear whether the PETTICOAT technique is superior to standard TEVAR.

OBJECTIVES

To assess the effects of combined proximal descending aortic endografting plus distal bare metal stenting versus conventional proximal descending aortic stent graft repair for treating complicated type B aortic dissections.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases, and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 5 November 2018. We also undertook reference checking and citation searching to identify additional studies.

SELECTION CRITERIA

We considered all randomised controlled trials which compared the outcome of complicated type B aortic dissection, when treated by combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) versus conventional proximal descending aortic stent graft repair.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed all references identified by the Cochrane Vascular Information Specialist. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We found no trials that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We identified no randomised controlled trials and therefore cannot draw any definite conclusion on this topic. Evidence from non-randomised studies appears to be favourable in the short-term, for combined proximal descending aortic endografting plus distal bare metal stenting (PETTICOAT technique) to solve the problem of unfavourable distal aortic remodeling. Randomised controlled trials are warranted to provide solid evidence on this topic. Evidence from cohort studies with large sample sizes would also be helpful in guiding clinical practice.

Thoracic endovascular aortic repair with stent grafts alone or with a composite device design in patients with acute type B aortic dissection in the setting of malperfusion

OBJECTIVE

The objective of this study was to compare short-term outcomes in patients who underwent thoracic endovascular aortic repair (TEVAR) with stent grafts alone or with a composite device design (stent graft plus bare-metal aortic stent) for acute type B aortic dissection in the setting of malperfusion.

METHODS

This retrospective analysis included patients with acute (≤14 days of symptom onset) complicated type B dissection in the setting of malperfusion who were treated with stent grafts alone (TEVAR cohort) at two European institutions vs those who underwent TEVAR with a composite device design (Cook Medical, Bloomington, Ind) in the investigational STABLE I feasibility study and STABLE II pivotal study (STABLE cohort). Preoperative characteristics and 30-day outcomes (including mortality, malperfusion-related mortality, morbidity, and secondary interventions) were compared between the two groups.

RESULTS

The TEVAR cohort (41 patients; mean age, 58.8 ± 12.7 years; 78.0% male) and the STABLE cohort (84 patients; mean age, 57.8 ± 11.7 years; 71.4% male) were largely similar in preoperative medical characteristics, with more STABLE patients presenting with a history of hypertension (79.8% vs 58.5%; P = .018). The TEVAR and STABLE groups had similar lengths of dissection (451.8 ± 112.7 mm vs 411.8 ± 116.4 mm; P = .10) and similar proximal and distal extent of dissection. At presentation, the two groups exhibited comparable organ system involvement in malperfusion: renal (53.7% TEVAR, 57.1% STABLE), gastrointestinal (41.5% TEVAR, 44.0% STABLE), lower extremities (34.1% TEVAR, 52.4% STABLE), and spinal cord (9.8% TEVAR, 2.4% STABLE). The 30-day rate of all-cause mortality was 17.1% (7/41) in the TEVAR group and 8.3% (7/84) in the STABLE group (P = .22). The 30-day rate of malperfusion-related mortality (deaths from bowel/mesenteric ischemia or multiple organ failure) was 12% (5/41) in the TEVAR group and 2.4% (2/84) in the STABLE group (P = .038). The 30-day morbidity, for the TEVAR and STABLE groups, respectively, included bowel ischemia (9.8% [4/41] vs 2.4% [2/84]; P = .09), renal failure requiring dialysis (7.3% [3/41] vs 9.5% [8/84]; P > .99), paraplegia or paraparesis (4.9% [2/41] vs 3.6% [3/84]; P = .66), and stroke (2.4% [1/41] vs 10.7% [9/84]; P = .16). The occurrence of 30-day secondary intervention was similar in the TEVAR and STABLE groups (7.3% [3/41] vs 7.1% [6/84]; P > .99). True lumen expansion in the abdominal aorta was significantly greater in the STABLE group.

CONCLUSIONS

In patients with acute type B aortic dissection in the setting of branch vessel malperfusion, the use of a composite device with proximal stent grafts and distal bare aortic stent appeared to result in lower malperfusion-related mortality than the use of stent grafts alone. The 30-day rates of morbidity and secondary interventions were similar between the groups.

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.

Distal Extended Endovascular Aortic Repair PETTICOAT: A Modified Technique to Improve False Lumen Remodeling in Acute Type B Aortic Dissection

BACKGROUND

Data from the literature suggest that in patients with acute, complicated type B aortic dissection (cTBAD), initial successful treatment with thoracic endovascular aneurysm repair (TEVAR) is not necessarily associated with favorable remodeling of the dissected aorta during follow-up, and long-term results indicate that TEVAR failed to completely suppress false lumen patency. Sealing of all relevant distal reentries, infrarenal and/or iliac, seems to be the key issue to induce total false lumen thrombosis in abdominal aorta as well as the iliac arteries, especially in complicated patients presenting with malperfusion or complete true lumen collapse.

MATERIALS AND METHODS

Of the 34 consecutive patients diagnosed with cTBAD at our hospital from January 2015 to April 2018, 30 had complicated dissections receiving endovascular treatment according to the standard Provisional ExTension To Induce COmplete ATtachment (PETTICOAT) technique and were excluded from this study, whereas 4 patients with radiologic evidence of multiple reentry tears at detached lumbar arteries and iliac bifurcation with complete true lumen collapse and clinical evidence of malperfusion were treated with a modified PETTICOAT technique with distal extension of the aortic stent, balloon expansion of the stented true lumen, and use of the AFX bifurcated endograft system to preserve the natural aortic bifurcation and provide complete distal sealing of reentry tears.

RESULTS

Primary technical success was achieved in all patients. No postoperative deaths were observed, but 1 patient experienced an hemorrhagic shock on the second postoperative day. No patient suffered postoperative stroke, paraplegia, paraparesis, or acute renal failure.

CONCLUSIONS

Using an abdominal aortic bifurcated endograft with PETTICOAT to treat acute cTBAD seems to be a feasible approach in high-risk patients to improve aortic remodeling. The AFX bifurcated endograft system meets the requirements of anatomical fixation and sealing of distal tears.