Treatment Of Aortic Dissection Research Articles

MOLS-Net: Multi-organ and lesion segmentation network based on sequence feature pyramid and attention mechanism for aortic dissection diagnosis

Aortic dissection is a rapid and critical cardiovascular disease. The automatic segmentation and detection of related organs and lesions in CT volumes of aortic dissection provide great help for the rapid diagnosis and treatment of aortic dissection. However, the diagnosis of aortic dissection involves multi-organ and lesion segmentation, which is also a multi-label segmentation problem. It faces many challenges, such as small target scale, variable location of the true and false lumen, and complex judgment. To solve these problems, this paper proposes a deep model (MOLS-Net) to segment and detect aortic dissection from CT volumes quickly and automatically. First, the sequence feature pyramid attention module correlates CT image sequence features of different scales and guides the current image segmentation by exploring the correlation between slices. Secondly, combine the spatial attention module and the channel attention module in the decoder of the network to strengthen the model’s positioning accuracy of the target area and the feature utilization. Thirdly, this paper designs a multi-label classifier for the inter-class relationship of multi-label segmentation of aortic dissection and realizes multi-label segmentation on the end-to-end network. In this paper, we evaluate MOLS-Net on multiple datasets (self-made aortic dissection segmentation dataset and COVID-19 CT segmentation dataset), and the results show that the proposed method is superior to other state-of-the-art methods.

Neuraminidase 1 Exacerbating Aortic Dissection by Governing a Pro-Inflammatory Program in Macrophages.

Inflammation plays an important role in aortic dissection (AD). Macrophages are critically involved in the inflammation after aortic injury. Neuraminidases (NEUs) are a family of enzymes that catalyze the cleavage of terminal sialic acids from glycoproteins or glycolipids, which is emerging as a regulator of macrophage-associated immune responses. However, the role of neuraminidase 1 (NEU1) in pathological vascular remodeling of AD remains largely unknown. This study sought to characterize the role and identify the potential mechanism of NEU1 in pathological aortic degeneration. After β-aminopropionitrile monofumarate (BAPN) administration, NEU1 elevated significantly in the lesion zone of the aorta. Global or macrophage-specific NEU1 knockout (NEU1 CKO) mice had no baseline aortic defects but manifested improved aorta function, and decreased mortality due to aortic rupture. Improved outcomes in NEU1 CKO mice subjected to BAPN treatment were associated with the ameliorated vascular inflammation, lowered apoptosis, decreased reactive oxygen species production, mitigated extracellular matrix degradation, and improved M2 macrophage polarization. Furthermore, macrophages sorted from the aorta of NEU1 CKO mice displayed a significant increase of M2 macrophage markers and a marked decrease of M1 macrophage markers compared with the controls. To summarize, the present study demonstrated that macrophage-derived NEU1 is critical for vascular homeostasis. NEU1 exacerbates BAPN-induced pathological vascular remodeling. NEU1 may therefore represent a potential therapeutic target for the treatment of AD.

Short-Term Outcomes of In Situ Fenestration in Total Endovascular Aortic Arch Treatment

The aim of this study was to analyze the short-term outcomes of in situ fenestration and discuss its feasibility and safety for the treatment of aortic dissection or aneurysm involving aortic arch. A retrospective single-center review was conducted on patients who were treated with ISF technique to revascularize supra-arch branches from Jun 2017 to Oct 2019. Computed tomographic angiography was performed to assess the patency of bridging stents, endoleaks and prognosis prior to discharge, after 3 months, 6 months, 12 months and yearly thereafter. Patient demographics, operative details, clinical outcomes, and complications were analyzed and then discussed in this paper. A total of 21 patients were diagnosed with arch pathologies, 5 type A aortic dissections, 12 type B aortic dissections and 4 thoracic aortic aneurysms. There were 19 men and 2 women (mean age 60.7 ± 15.3). 8 cases were treated with three-fenestration stent grafts, 1 case with two-fenestration stent graft, and 12 cases with single-fenestration stent grafts. Overall technical success rate was 95.2%. Mean operation time was 227.4 ± 143.8 minutes. Complications were intraoperative hemorrhage (>1000 ml, 2), stroke (2), hydropericardium (1) and endoleaks (2 type Ⅲ, 1 type Ⅰ). There was no aorta-related mortality or late endoleaks during the mean follow-up of 25.5 ± 6.2 months. All the bridging stents remained patent and there was no migration according to follow-up Computed tomographic angiography. With low complication and mortality rate, ISF is an effective and feasible method for the total endovascular aortic arch repair. Long-term follow-up study is needed to evaluate its durability.

Plasma Lipidomics Identifies Unique Lipid Signatures and Potential Biomarkers for Patients With Aortic Dissection.

Aortic dissection (AD) is a catastrophic cardiovascular emergency with a poor prognosis, and little preceding symptoms. Abnormal lipid metabolism is closely related to the pathogenesis of AD. However, comprehensive lipid alterations related to AD pathogenesis remain unclear. Moreover, there is an urgent need for new or better biomarkers for improved risk assessment and surveillance of AD. Therefore, an untargeted lipidomic approach based on ultra-high-performance liquid chromatograph-mass spectrometry was employed to unveil plasma lipidomic alterations and potential biomarkers for AD patients in this study. We found that 278 of 439 identified lipid species were significantly altered in AD patients (n = 35) compared to normal controls (n = 32). Notably, most lipid species, including fatty acids, acylcarnitines, cholesteryl ester, ceramides, hexosylceramides, sphingomyelins, lysophosphatidylcholines, lysophosphatidylethanolamines, phosphatidylcholines, phosphatidylinositols, diacylglycerols, and triacylglycerols with total acyl chain carbon number ≥54 and/or total double bond number ≥4 were decreased, whereas phosphatidylethanolamines and triacylglycerols with total double bond number <4 accumulated in AD patients. Besides, the length and unsaturation of acyl chains in triacylglycerols and unsaturation of 1-acyl chain in phosphatidylethanolamines were decreased in AD patients. Moreover, lysophosphatidylcholines were the lipids with the largest alterations, at the center of correlation networks of lipid alterations, and had excellent performances in identifying AD patients. The area under the curve of 1.0 and accuracy rate of 100% could be easily obtained by lysophosphatidylcholine (20:0/0:0) or its combination with lysophosphatidylcholine (17:0/0:0) or lysophosphatidylcholine (20:1/0:0). This study provides novel and comprehensive plasma lipidomic signatures of AD patients, identifies lysophosphatidylcholines as excellent potential biomarkers, and would be beneficial to the pathogenetic study, risk assessment and timely diagnosis and treatment of AD.

Application of the Type, Entry Site, and Malperfusion Classification in Treatment of Aortic Dissection.

Our goal is to investigate a new practical dissection classification system, including type of dissection, location of the tear of the primary entry, and malperfusion. The outcome of 151 patients with aortic dissection between January 2019 and May 2020 retrospectively were analyzed. All cases were classified with the Stanford dissection classification (A and B) by adding type non-A non-B. They were then further classified by the new classification system, including location of the primary Entry (E) and Malperfusion (M). All cases were followed up for six months. The distribution of 151 patients was 53.0%, 27.8%, and 19.2%, respectively, in type A, B, and non-A non-B. The in-hospital mortality rate was 8.8%, 2.4%, and 3.4% in type A, B, and non-A non-B (P < 0.05) and postoperative neurological complications occurred in 33.8%, 7.1%, and 13.8% in type A, B, and non-A non-B (P < 0.05). Total arch replacement was performed in 53.8%, 4.8%, and 13.8% in type A, B, and non-A non-B. The in-hospital mortality rate was 12.0%, 10.4%, and 8.5% in type E1, E2 and E3, while it was 20.0%, 10.4%, and 8.5% in type M1, M2 and M3 (P < 0.05). The new practical dissection classification system is useful as a supplement to the Stanford dissection classification by regarding the extent of the disease process, aiding in decision-making about the operative indication and plan, and helping in anticipating prognosis.

Male-female differences in acute thoracic aortic dissection: a systematic review and meta-analysis.

OBJECTIVESThis study aims to systematically review published literature on male–female differences in presentation, management and outcomes in patients diagnosed with acute thoracic aortic dissection (AD).METHODSA systematic literature search was conducted for studies published between 1 January 1999 and 19 October 2020 investigating mortality and morbidity in adult patients diagnosed with AD. Patient and treatment characteristics were compared with odds ratios (ORs) and standardized mean differences and a meta-analysis using a random-effects model was performed for early mortality. Overall survival and reoperation were visualized by pooled Kaplan–Meier curves.RESULTSNine studies investigating type A dissections (AD-A), 1 investigating type B dissections (AD-B) and 3 investigating both AD-A and AD-B were included encompassing 18 659 patients. Males were younger in both AD-A (P < 0.001) and AD-B (P < 0.001), and in AD-A patients males had more distally extended dissections [OR 0.57, 95% confidence interval (CI) 0.46–0.70; P < 0.001]. Longer operation times were observed for males in AD-A (standardized mean difference 0.29, 95% CI 0.17–0.41; P < 0.001) while male patients were less often treated conservatively in AD-B (OR 0.65, 95% CI 0.58–0.72; P < 0.001). The pooled early mortality risk ratio for males versus females was 0.94 (95% CI 0.84–1.06, P = 0.308) in AD-A and 0.92 (95% CI 0.83–1.03, P = 0.143) in AD-B. Pooled overall mortality in AD-A showed no male–female difference, whereas male patients had more reinterventions during follow-up.CONCLUSIONSThis systematic review shows male–female differences in AD patient and treatment characteristics, comparable early and overall mortality and inconsistent outcome reporting. As published literature is scarce and heterogeneous, large prospective studies with standardized reporting of male–female characteristics and outcomes are clearly warranted. Improved knowledge of male–female differences in AD will help shape optimal individualized care for both males and females.Clinical registration numberPROSPERO, ID number: CRD42020155926.

Therapeutic window for obtaining favorable remodeling after thoracic endovascular aortic repair of type B aortic dissection

ObjectiveThe purpose of the present study was to determine the most appropriate timing for thoracic endovascular aortic repair (TEVAR) of type B aortic dissection (TBAD) in terms of remodeling of the aorta. MethodsA total of 41 patients who had undergone TEVAR for the treatment of aortic dissection were included in the present study. The patients were divided into two groups: those who had undergone TEVAR in the acute or subacute phase (group A) and those who had undergone TEVAR in the chronic phase (group B). The indications for TEVAR as the treatment of TBAD were the presence of aortic rupture or malperfusion of the aortic branches, a maximum aortic diameter of ≥40 mm on the initial diagnostic computed tomography scan, and/or expansion of the aorta of ≥5 mm within 3 months for acute and subacute TBAD. The indication was a maximum aortic diameter of ≥50 mm or expansion of the aorta of ≥5 mm within 1 year for chronic TBAD. The diameters of the aorta, true lumen, and false lumen were measured at the level of the most dilated part of the descending aorta (level M) and at the diaphragm (level D) on the computed tomography scan obtained before TEVAR and at the 2-year follow-up examination. ResultsThe median interval between TEVAR and the onset of TBAD was 0.2 month (interquartile range, 0.03-0.7 month) in group A (n = 21) and 32 months (interquartile range, 4.7-35.2 months) in group B (n = 20). Except for the aortic diameter at level D in group B, favorable remodeling was obtained at both levels in both groups. The diameter change ratio of the aorta at level D was significantly greater in group A than in group B (P = .02). Receiver operating characteristic curve analysis of the interval for a significant decrease in the aortic diameter at level D yielded 4.2 months as the optimal threshold for performing TEVAR (area under the curve, 0.859; 95% confidence interval, 0.7-1.0). ConclusionsTEVAR for TBAD will result in favorable outcomes, irrespective of the timing of the procedure. However, it might be more effective to perform TEVAR within 4.2 months of the onset of TBAD, provided that the TEVAR procedure can be performed safely.

Long-Term Outcomes of Surgical Treatment for Acute Type-A Aortic Dissection with Coronary Artery Involvement.

The surgical strategies for acute type-A aortic dissection (aTAAD) with coronary artery involvement have been controversial, and its prognosis remains unclear. Thus, in this study, we aim to determine the characteristics, surgical strategies, and prognosis of patients with coronary artery involvement due to aTAAD.Retrospective analysis of 65 consecutive aTAAD patients with coronary artery involvement between September 2005 and January 2012 was performed. The patients were divided into two groups: those treated with aTAAD repair and coronary ostia reimplantation (Neri type-A, group A, n = 37) and those with aTAAD repair and coronary artery bypass grafting (Neri type B and C, group B, n = 28).Overall in-hospital mortality was determined to be 8.1% for group A and 21.4% for group B (P = 0.124). No significant difference was determined between groups A and B in cardiopulmonary bypass time, cross-clamp time, cerebral perfusion time, and hospitalization time. Intensive care unit (ICU) stay was 5.8 ± 7.4 days for group A, whereas it was 12.4 ± 10.6 days for group B (P = 0.009). The morbidity of postoperative temporary and permanent neurological dysfunction was similar between the two groups, while renal and respiratory dysfunction were 8.1% versus 25.0% and 16.2% versus 39.3%, respectively (P = 0.062, P = 0.036). Average follow-up time was 112.0 ± 44.8 months, and survival curves have not shown statistical significance between two groups (P = 0.386).Coronary artery dissection with Neri type B and C in acute TAAD has been associated with higher early death, but comparable long-term survival after discharge. However, combined immediate coronary artery bypass grafting and aortic repair remains a safe, effective, and acceptable approach to these challenging group of patients.

Early and mid-term outcomes of thoracic aortic reconstruction using the frozen elephant trunk technique: A single-center retrospective study

Background. The frozen elephant trunk (FET) technique for the treatment of both thoracic aortic aneurysms and dissections has become universally popular over the past two decades because extensive open surgical reconstruction of the thoracic aorta has been found to be associated with high complication and mortality rates or unfavourable long-term outcomes as it requires repeated interventions. The FET technique has also been shown to produce excellent, immediate and long-term results. Hence, it is important to evaluate the outcomes of thoracic aortic reconstruction using this technique.Aim. This study aimed to investigate immediate and long-term outcomes of the FET technique in patients with thoracic aortic diseases.Methods. We retrospectively analysed the pre-, intra- and post-operative data of 40 patients with distal aortic arch aneurysm who had undergone aortic arch reconstruction using the FET technique at Meshalkin National Research Medical Center from February 2012 to October 2020. To assess the early and long-term post-operative survival of these patients, we categorised them into group I (including 14 patients without aortic dissection) and group II (including 26 patients with type I and type III aortic dissections).Results. The in-hospital survival rates for groups I and II were found to be 68.5% and 95.9%, respectively (log rank, p = 0.048). Groups I and II did not differ significantly in the incidence of stroke (7.1% vs 7.7%, respectively; p = 0.724) and spinal cord ischaemia (14.3% vs 0%, respectively; p = 0.117). Long-term (1-, 3- and 5-year) survival rates in group II remained unchanged at 95.9%, whereas survival rates at 30 days, 6 months and 1 year in group I were 91.3%, 68.5% and 57%, respectively. The risk of mortality was 90% lower in group II than in group I, with a hazard ratio of 0.096 and a 95% confidence interval of 0.01–0.81 (p = 0.038). The rates of freedom from thoracoabdominal aortic interventions in group II were 91.8%, 83%, 64.7%, 59.3% and 59.3% at 30 days, 6 months, 1 year, 3 years and 5 years, respectively; these rates in group I were 90.9%, 75.7% and 75.7% at 30 days, 6 months and 1 year, respectively. There was no significant difference between the groups concerning thoracoabdominal aortic interventions (log rank, p = 0.587).Conclusion. The use of the FET technique in patients with thoracic aortic diseases is associated with acceptable rates of mortality and thoracoabdominal aortic interventions in immediate and long-term post-operative periods.Received 28 January 2021. Revised 28 April 2021. Accepted 29 April 2021.Funding: This work was carried out within the framework of the state task of the Ministry of Health of the Russian Federation (No. 121032300337-5).Conflict of interest: The authors declare no conflicts of interests.Contribution of the authors: The authors contributed equally to this article.

Association of Mental Health Disorders and Aortic Dissection

Mental health disorders (MHD), including substance abuse, have been associated with aortic dissection (AD). Aneurysmal degeneration in the residual untreated aorta after both open and endovascular treatment is not uncommon in AD. Thus, diligent long-term follow-up is necessary and MHD may play a role in treatment plan and surveillance. The impact of MHD on management, outcomes and follow-up after AD treatment is unknown and here we sought to evaluate these associations. A retrospective review was performed on all patients diagnosed with Stanford Type A and B dissections from 2008 to 2018 at a tertiary referral center. MHD was defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). Patient demographics, procedural characteristics, and outcomes were analyzed. A total of 649 non-traumatic aortic dissections were identified in the study timeframe. The cohort consisted of 51% Type A (n=334) dissection and 49% Type B (n=315) dissection. Mental health disorders were present in 49.3% of the cohort. Notably, the timing of MHD diagnosis relative to development of AD is unknown in the majority of patients. Within the Type A population, a MHD was present in 50.6% (N=162) of patients, of which the most common indication for MHD was the presence of antidepressant or antipsychotic medication (28.6%). In patients with Type A dissections, the presence of a MHD did not significantly affect the rate of index hospitalization intervention (68%) or long-term mortality (12.5% in patients with a MHD). Within the Type B population, a MHD was present in 49.4% (n=158) of patients, of which the most common indication for MHD was the presence of antidepressant or antipsychotic medication (30.5%). In patients with Type B dissections, the presence of a MHD did not significantly affect the rate of index hospitalization intervention (50.3% in patients with a MHD) or long-term mortality (10.1% in patients with a MHD). The overall participation in follow-up care was not significantly decreased based on the presence of a MHD compared to those without a MHD (1.66 ± 2.16 years vs. 1.68 ± 2.20 years, P=0.93). MHD is more prevalent in AD patients than in the general population, but demonstrating a causal relationship between MHD and development/progression of AD is challenging. Despite a high prevalence of MHD in AD patients, in-hospital mortality and follow-up compliance was similar to non-MHD patients.

Changes of stent-graft orientation after frozen elephant trunk treatment in aortic dissection.

Our goal was to evaluate the extent of stent-graft (SG) elastic recoil in the descending aorta after the frozen elephant trunk procedure in acute (AAD) and chronic (CAD) aortic dissection as well as the impact of SG movement on distal stent graft-induced new entry (d-SINE). We retrospectively analysed 149 (105 AAD, 44 CAD) of 259 aortic dissection patients after the frozen elephant trunk procedure between January 2005 and April 2019. Inclusion criteria were at least 1-year computed tomography angiography (CTA) aortic examinations during a follow-up time of 3.8 ± 2.7 years and absence of open or endovascular reintervention. Multiplanar reconstruction of CTA scans was used to define the SG vector position and movement in a virtual Cartesian coordinate system. The angle φ of vector movement and changes of aortic areas at the distal landing zone were analysed. The distal SG position changed over time in the cranial (10.06 ± 11.12 mm), dorsal (8.45 ± 11.12 mm) and lateral (4.96 ± 9.89 mm) directions (P < 0.001). The total change of φ (4.08 ± 7.03°) was greater in AAD than in CAD (P = 0.026). d-SINE was more common in CAD (P < 0.001) and was associated with the size of the aortic area, aortic area enlargement and continuous SG unfolding (P < 0.001). With the frozen elephant trunk technique, movement and change of SG orientation in the descending aorta were observed over time. Elastic recoil was greater in AAD than in CAD. The incidence of d-SINE was particularly dependent on the size of the aortic lumen and SG radial expansion and less on elastic recoil.

Hybrid repair versus conventional open repair for aortic arch dissection

A dissection of the aorta is a separation or tear of the intima from the media. This tear allows blood to flow not only through the original aortic flow channel (known as the true lumen), but also through a second channel between the intima and media (known as the false lumen). Aortic dissection is a life-threatening condition which can be rapidly fatal. There is debate on the optimal surgical approach for aortic arch dissection. People with ascending aortic dissection have poor rates of survival. Currently open surgical repair is regarded as the standard treatment for aortic arch dissection. We intend to review the role of hybrid and open repair in aortic arch dissection.To assess the effectiveness and safety of a hybrid technique of treatment over conventional open repair in the management of aortic arch dissection.The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 8 February 2021. We also undertook reference checking for additional studies.We included randomised controlled trials (RCTs) and clinical controlled trials (CCTs), which compared the effects of hybrid repair techniques versus open surgical repair of aortic arch dissection. Outcomes of interest were dissection-related mortality and all-cause mortality, neurological deficit, cardiac injury, respiratory compromise, renal ischaemia, false lumen thrombosis (defined by partial or complete thrombosis) and mesenteric ischaemia.Two review authors independently screened all records identified by the literature searches to identify those that met our inclusion criteria. We planned to undertake data collection and analysis in accordance with recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions. We planned to assess the certainty of the evidence using GRADE.We identified one ongoing study and two unpublished studies that met the inclusion criteria for the review. Due to a lack of study data, we could not compare the outcomes of hybrid repair to conventional open repair for aortic arch dissection.This review revealed one ongoing RCT and two unpublished RCTs evaluating hybrid versus conventional open repair for aortic arch surgery. Observational data suggest that hybrid repair for aortic arch dissection could potentially be favourable, but conclusions can not be drawn from these studies, which are highly selective, and are based on the clinical status of the patient, the presence of comorbidities and the skills of the operators. However, a conclusion about its definitive benefit over conventional open surgical repair cannot be made from this review without published RCTs or CCTs. Future RCTs or CCTs need to have adequate sample sizes and follow-up, and assess clinically-relevant outcomes, in order to determine the optimal treatment for people with aortic arch dissection. It must be noted that this may not be feasible, due to the reasons mentioned.

Macrophage-biomimetic anti-inflammatory liposomes for homing and treating of aortic dissection

Aortic dissection (AD) is a life-threatening disease featured by the dissection of intimal layer and the formation of a blood-filled false lumen within the aortic wall. Recent studies revealed that the formation and progression of AD lesions is closely related to vascular inflammation and macrophage infiltration. However, the potential efficacy of anti-inflammatory therapy on the prevention and treatment of AD has not been extensively investigated. Herein, we proposed a biomimetic anti-inflammatory liposome (PM/TN-CCLP) co-loaded with curcumin and celecoxib (CC), modified with cell-penetrating TAT-NBD fusion peptide (TN), and further camouflaged by isolated macrophage plasma membrane (PM), as a potential nanotherapy for AD. In vitro results showed that PM/TN-CCLP exhibited low cytotoxicity and elevated cellular uptake by inflammatory macrophages, and prominently inhibited the transendothelial migration, inflammatory responses and ROS generation of macrophages. Moreover, the PM/TN-CCLP treatment significantly prevented the H2O2-induced smooth muscle cell apoptosis. In vivo experiments were performed on the acute and chronic AD mouse models, respectively. The results verified the elevated accumulation of PM-camouflaged liposome at the aorta lesions. Further, the anti-inflammatory liposomes, especially PM/TN-CCLP, could reduce the rupture rate of dissection, prevent the loss of elastic fibers, and reduce MMP-9 expression as well as macrophage infiltration in the aortic lesions. Notably, as compared with free drugs and TN-CCLP, the PM/TN-CCLP treatment displayed the longest survival period along with the minimal aortic injury on both acute and chronic AD mice. Taken together, the present study suggested that the macrophage-biomimetic anti-inflammatory nanotherapy would be a promising strategy for the prevention and therapy of aortic dissection.

Is TEVAR really needed for uncomplicated type B aortic dissection?

Thoracic endovascular aortic repair (TEVAR) has quickly become the mainstay of treatment for acute aortic dissection, in particular cases of acute complicated Stanford Type B dissection (co-TBAD). Necessarily, TEVAR carries with it the risk of postoperative complications, including stroke and renal failure. As a result, the management of patients with uncomplicated type B aortic dissection (un-TBAD), which is generally accepted as being less severe, is safely managed via optimal medical therapy (OMT) alone. However, despite OMT, patients with un-TBAD are at substantial risk of severe disease progression requiring delayed intervention. The cost-benefit ratio associated with TEVAR for un-TBAD is therefore of key interest. Howard and colleagues produced a fascinating systematic review and meta-analysis investigating the clinical outcomes of TEVAR for complicated and uncomplicated TBAD. Their data suggest that there is no significant difference in in-hospital mortality or 5-year survival between TEVAR for un-TBAD and co-TBAD, although the 30-day mortality rate appeared to be higher in the co-TBAD cohort. Patients with co-TBAD appeared to also be at a higher risk of postoperative stroke and TEVAR endoleak, while un-TBAD patients were at a higher risk of postoperative renal failure. Further prospective research into these relationships is recommended to fully elucidate the comparative efficacies of TEVAR for un-TBAD and co-TBAD.

Aortic remodeling and competitive flow after surgical treatment of aortic dissection

Aortic remodeling after dissection is poorly understood and remains a focus of current research. In the present report, we have described the cases of two patients with acute lower extremity ischemia related to malperfusion from aortic dissection treated with extra-anatomic axillobifemoral bypass. During long-term follow-up, aortic remodeling led to reinstitution of flow through the native aorta. This resulted in competitive flow, leading to complete thrombosis of the extra-anatomic conduits. These cases highlight the occurrence of spontaneous aortic recanalization and subsequent competitive flow, two vascular phenomena that are not well understood but can significantly affect patient outcomes.

Long-Term Outcomes of Thoracic Endovascular Repair for Aortic Arch Dissection Using Customized Single-Branched Fenestrated Stent-Graft.

To report outcomes of thoracic endovascular repair using customized single-branched fenestrated stent-grafts in treatment of aortic arch dissections. Between November 2009 and November 2011, 16 patients with aortic arch dissections underwent thoracic endovascular aortic repair utilizing customized unibody single-branched fenestrated stent-graft (UBFSG) in our institution. All 16 patients were male with mean age of 54.50 ± 11.33. The technical success rate was 100%. 30-day mortality rate was 6.25% (n = 1). The median follow-up period was 98 months (range, 0-119). During follow-up, 4 nonaorta-related deaths were recorded. Two (2) cases of left subclavian artery occlusion were observed 12 and 14 months after the operation. Two (2) patients had another successful endovascular repair in time, including one case of type Ib endoleak occurred 100 months after the operation and one case of stent-graft induced new entry tear 38 months after the operation. No stroke and migration of stent-grafts were observed. The branched fenestrated stent-graft may be an effective alternative treatment for aortic arch dissections unfit for open surgery.

GUIDANCE ON AREA OF CREATED TEARS FOR AORTIC FENESTRATION TREATMENT BASED ON COMPUTATIONAL FLUID DYNAMICS

Aortic fenestration (AF) uses puncture and a dilation balloon to create a tear in the intimal flap, which can directly relieve ischemia syndrome and reduce hypertension in the false lumen. The selection of a dilation balloon as well as the area of the created tear applied in reality depend on clinical experience, so we aim to provide a quantitative guidance and reference for doctors to better plan the treatment of aortic fenestration. In this study, the area of the created tear was virtually enlarged to at least 10 different values for four cases including one ideal case, and a computational fluid dynamic approach was applied to simulate blood flows in the aorta. The area ratio (AR) between the created tear and entry tear was introduced to express the enlargement of the created tear. The quantitative hemodynamic results indicate that the AR should be controlled to be larger than 7.0, but not too big to obtain the best treatment for acute aortic dissection (AD) case. Additionally, we assessed that AR might also be a risk factor for the prediction of dissection propagation.

Surgeon-modified fenestrated stent graft deployment in type B aortic dissection.

The treatment of aortic dissections and aneurysms may be challenging for vascular surgeons. Currently, thoracic endovascular aortic repair is usually the first treatment option for descending aortic pathologies. Left subclavian artery coverage during this procedure is often required to achieve a sufficient proximal landing zone. Most surgeons agree that the left subclavian artery can be selectively covered, but revascularization is preferred to reduce the risk of neurological or ischemic complications. The chimney method, hybrid operations with extra-anatomic bypass, back table or in situ fenestrations are assistive techniques in this procedure. Herein, we present a surgeon-modified fenestrated stent graft for a type B aortic dissection patient.

Efficacy of endovascular treatment of distal aortic dissection involving abdominal visceral segment with bare-metal stents related technique

Objective: To investigate the effect of bare-metal stent related technique on distal aortic dissection involving abdominal visceral segment. Methods: A retrospective analysis was performed on clinical data of 33 patients with distal aortic dissection involved abdominal visceral segment, who hospitalized in the Vascular Surgery Department of Shanghai Changhai Hospital from July 2012 to September 2019. The effect of the treatment was evaluated according to the clinical and preoperative, intraoperative and follow-up imaging data derived from (aorta computed tomography angiography (CTA) and digital subtraction angiography (DSA)) as well as the changes of the maximal diameter of the aorta and the thrombosis of the false lumen of the dissection. The criteria were as follows: the maximum diameter change of aortic dissection<5 mm was defined as stable; the maximum diameter decrease of aortic dissection≥5 mm was defined as effective reduction; the maximum diameter increase of aortic dissection≥5 mm was defined as expansion; the definition of diameter change of false lumen was the same as above. The hospital complications, clinical symptoms and survival were recorded. Results: There were 28 male patients in this cohort, the mean age was (57.6±4.9) years old. Twenty-one patients were treated with bare-metal stent and coils technique, of which 8 patients were jointly treated with stent grafts. Twelve patients were treated with multi-layer bare-metal stent technique, of which 4 patients were jointly treated with stent grafts. Intraoperative DSA image results showed that the visceral arteries were patent during the treatment, and the blood flow velocity of the false lumen was reduced in all 33 patients. There were no adverse events such as distal outflow tract embolism and coil displacement during the operation. During the period of hospitalization, one patient developed intimal rupture of subrenal abdominal aortic dissection on the fourth day after operation and emergency endovascular graft exclusion was performed for abdominal aortic dissection, and the patient recovered well from the emergency operation. The follow-up time was (16.7±14.0) months. One patient died 1 year after surgery due to non-disease-related factors. Follow-up CTA imaging results showed that the maximum diameter of the aorta in abdominal visceral segment tended to be smaller ((39.1±13.4) mm vs. (41.3±11.9) mm, P=0.469), and the maximum diameter of the false lumen was significantly reduced ((16.2±12.9) mm vs. (23.5±10.7) mm, P=0.014). The maximum diameter of the aortic dissection was reduced in 12 cases, stable in 19 cases, expanded in 2 cases. The maximum diameter of the false lumen was effectively reduced in 22 cases, stable in 10 cases, and expanded in 1 case. Four patients developed small endoleak in the false lumen, one of them was nearby the renal artery stent, and the remaining patients experienced complete thrombosis of the false lumen. Conclusions: Endovascular treatment of distal aortic dissection involving abdominal visceral segment with bare-metal stents related technique could promote the shrink and the thrombosis of the false lumen, and slow down the blood flow from the tear into the false lumen in the setting of patency of visceral arteries.

Aortic aneurysms and dissections: Unmet needs from physicians and engineers perspectives

The treatment of aortic disease is complex, requiring cardiothoracic and vascular surgeons to make pre-, post- and intraoperative decisions directly influencing patient survival and well-being. Despite tremendous advancement in vascular surgery and endovascular techniques in the last two decades, along with the abundance of research in the field, many unmet needs and unanswered questions remain. Tight collaboration between engineers and physicians is a keystone in translating new tools, techniques, and devices into practice. Here, we have gathered our perspective, as physicians and engineers, in several pressing issues associated with the diagnosis and treatment of aortic aneurysms and dissection, referring to the current knowledge and practice, signifying unmet needs as well as future directions.