Distinction between Acute and Chronic Type B Aortic Dissection: Is there a Sub-acute Phase?

Current perspectives in acute type B aortic dissections: a literature review

In this new millennial, endovascular strategies have revolutionized the treatment of acute type B aortic dissection (aTBAD). With reduced in-hospital mortality and good long-term outcomes TEVAR has become the gold standard for the treatment of complicated dissection and is gaining increasing support for its preventive applicability in some uncomplicated dissections. With this new paradigm came a shift of the treatment goal where just covering the entry tear is not enough and instead achieving long-term positive thoracoabdominal remodeling is needed. More extensive approaches with composite device designs (covered stent graft and bare metal stent) emerged to answer this aortic conundrum. At 5-year of follow-up, "Provisional ExTension To Induce COmplete Attachment technique" (PETTICOAT) and its evolution "Stent assisted balloon induced intimal disruption and relamination in aortic dissection repair" (STABILISE) seem to be safe techniques that can allow, when anatomically feasible, excellent aortic remodeling and, in some cases, even the healing of the dissection. Nevertheless, STABILISE results, although promising, are mostly based on small series and therefore need to be validated by analyzing medium-long-term results from the international registry. Given the plethora of new data and the disparity of expert opinions on the best treatment to adopt, in this review we aim to summarize the current knowledge on the results of these different strategies for acute TBAD.

Male-Female Differences in Acute Type B Aortic Dissection

BACKGROUND

Acute type B aortic dissection is a cardiovascular emergency with considerable mortality and morbidity risk. Male-female differences have been observed in cardiovascular disease; however, literature on type B aortic dissection is scarce.

METHODS AND RESULTS

A retrospective cohort study was conducted including all consecutive patients with acute type B aortic dissection between 2007 and 2017 in 4 tertiary hospitals using patient files and questionnaires for late morbidity. In total, 384 patients were included with a follow-up of 6.1 (range, 0.02-14.8) years, of which 41% (n=156) were female. Women presented at an older age than men (67 [interquartile range (IQR), 57-73] versus 62 [IQR, 52-71]; P=0.015). Prior abdominal aortic aneurysm (6% versus 15%; P=0.009), distally extending dissections (71 versus 85%; P=0.001), and clinical malperfusion (18% versus 32%; P=0.002) were less frequently observed in women. Absolute maximal descending aortic diameters were smaller in women (36 [IQR: 33-40] mm versus 39 [IQR, 36-43] mm; P<0.001), while indexed for body surface area diameters were larger in women (20 [IQR, 18-23] mm/m2 versus 19 [IQR, 17-21] mm/m2). No male-female differences were found in treatment choice; however, indications for invasive treatment were different (P<0.001). Early mortality rate was 9.6% in women and 11.8% in men (P=0.60). The 5-year survival was 83% (95% CI, 77-89) for women and 84% (95% CI, 79-89) for men (P=0.90). No male-female differences were observed in late (re)interventions.

CONCLUSIONS

No male-female differences were found in management, early or late death, and morbidity in patients presenting with acute type B aortic dissection, despite distinct clinical profiles at presentation. More details on the impact of age and type of intervention are warranted in future studies.

Prognosis and Remodeling after Endovascular Repair for Acute, Subacute, and Chronic Type B Aortic Dissection

PURPOSE

Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) is already well introduced, but the best time point to perform TEVAR has not been defined. This study was to report mid- to long-term outcomes and aortic remodeling of TEVAR in patients with TBAD.

MATERIALS AND METHODS

In total, 318 TBAD patients from June 2001 to May 2016 were retrospectively reviewed. Patients were divided into 3 groups depending on interval between dissection onset to TEVAR: acute (0-7 days), subacute (8-30 days), and chronic (>30 days). Clinical and morphological data were collected and analyzed.

RESULTS

The follow-up aorta-related mortality rates in the 3 groups were 17.6%, 2.6%, 4.2%, and the proximal stent-induced new entry rates were 11.8%, 1.6%, 2.8%, respectively. Aortic remodeling was satisfied in both the acute and subacute group, but the false lumen diameter did not decrease (p>0.05) in the chronic group. Compared with the VIRTUE classification (acute, 0-14 days; subacute, 15-92 days; chronic, >92 days), mid- to long-term outcomes of patients within the first overlapped interval between the 2 classifications (8-14 days) were similar to that of subacute patients (15-30 days), while aortic remodeling of patients in the second overlapped interval (31-92 days) was similar to that of chronic patients (>92 days).

CONCLUSIONS

This study suggests that TEVAR for subacute TBAD is associated with a low long-term rate of aorta-related death. Aortic remodeling of chronic dissections is not satisfactory. Additional results suggest that the subacute phase (8-30 days) may be the optimal time to perform TEVAR for uncomplicated TBAD.

Male-female differences in thoracic aortic diameters at presentation of acute type A aortic dissection

Background

Acute type A aortic dissection (ATAAD) is a highly lethal event, associated with aortic dilatation. It is not well known if patient height, weight or sex impact the thoracic aortic diameter (TAA) at ATAAD. The study aim was to identify male-female differences in TAA at ATAAD presentation.

Methods

This retrospective cross-sectional study analysed all adult patients who presented with ATAAD between 2007 and 2017 in two tertiary care centres and underwent contrast enhanced computed tomography (CTA) before surgery. Absolute aortic diameters were measured at the sinus of Valsalva (SoV), ascending (AA) and descending thoracic aorta (DA) using double oblique reconstruction, and indexed for body surface area (ASI) and height (AHI). Z-scores were calculated using the Campens formula.

Results

In total, 59 % (181/308) of ATAAD patients had CT-scans eligible for measurements, with 82 female and 99 male patients. Females were significantly older than males (65.5 ± 12.4 years versus 60.3 ± 2.3, p = 0.024). Female patients had larger absolute AA diameters than male patients (51.0 mm [47.0-57.0] versus 49.0 mm [45.0-53.0], p = 0.023), and larger ASI and AHI at all three levels. Z-scores for the SoV and AA were significantly higher for female patients (2.99 ± 1.66 versus 1.34 ± 1.77, p < 0.001 and 5.27 [4.38-6.26] versus 4.06 [3.14-5.02], p < 0.001). After adjustment for important clinical factors, female sex remained associated with greater maximal TAA (p = 0.019).

Conclusion

Female ATAAD patients had larger absolute ascending aortic diameters than males, implying a distinct timing in disease presentation or selection bias. Translational studies on the aortic wall and studies on growth patterns should further elucidate these sex differences.

Outcomes of open repair for descending thoracic and thoracoabdominal aortic aneurysm in recent 10 years: experience of a high-volume centre in Korea

OBJECTIVES

Although recent studies and guidelines suggest the preferred outcomes after surgical repair of thoracic aortic aneurysm (TAA) and thoracoabdominal aortic aneurysm (TAAA), published results are limited to those from high-volume hospitals and based on old data gathered before optimal management was established. Here, we analysed our outcomes over the previous 10 years from cases of open TAA and TAAA repair to offer updated and real-world results of those complex procedures performed in a high-volume centre.

METHODS

From November 2013 to April 2022, 212 consecutive adult patients who underwent open TAA and TAAA repair were enrolled. We analysed early and late outcomes after surgery, including postoperative complications and mortality.

RESULTS

There were 154 (73%) men, and the median age at surgery was 61 years. Intraoperative death occurred in 1 patient due to uncontrolled bleeding. Nine patients (4%) died during follow-up, and the survival estimates at 5 years were 94 ± 3% and 95 ± 3% after descending TAA and TAAA repair, respectively. Ten patients (4%) suffered from spinal cord ischaemic injury (9 with paraplegia and 1 with paresthesia), but permanent paraplegia persisted in only 1 case.

CONCLUSIONS

We report very low postoperative complication rates and excellent early and late survival rates after open TAA and TAAA repair from our recent 10-year data analysis. These findings may assist when choosing treatment options for these complicated diseases.

Longitudinal Assessment of Inflammatory Activity in Acute Type B Aortic Dissection with Integrated Fluorodeoxyglucose Positron Emission Tomography/Magnetic Resonance Imaging

OBJECTIVE

The significance of the inflammatory response in the natural course of acute type B aortic dissection (ATBAD) is unknown. The aim was to characterise inflammation and its transformation over time in ATBAD using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) with contrast enhanced magnetic resonance imaging (MRI).

METHODS

Ten patients underwent FDG-PET/MRI within two weeks of ATBAD (acute phase), three to four months (subacute phase), nine to 12 months (early chronic phase), and 21 to 24 months (late chronic phase) after ATBAD. Target background ratios (TBRs) were measured in the ascending aorta, aortic arch, and descending aorta. MRI inflammatory markers were assessed in the descending aorta.

RESULTS

Ten patients were included: median age 69 years, median clinical follow up 32 months. In the acute phase there was increased FDG uptake in the descending aorta (maximum TBR 5.8, SD [standard deviation] 1.3) compared with the ascending aorta (TBR 3.3, SD 0.8, p < .010) and arch (TBR 4.2, SD 0.6, p = .010). The maximum TBR of the descending aorta decreased from the acute to subacute phase (TBR 3.5, SD 0.6, p = .010) and further to the early chronic phase (TBR 2.9, SD 0.4, p = .030) but was stable thereafter. The acute phase maximum TBR in the ascending aorta (TBR 3.3) and arch (TBR 4.2) decreased to the subacute phase (ascending: TBR 2.8, SD 0.6, p = .020; arch: TBR 2.7, SD 0.4, p = .010) and was stable thereafter. Four patients underwent surgical aortic repair (three for aortic dilatation at one, five, and 28 months and one for visceral ischaemia at three weeks). MRI signs of inflammation were present in all surgically treated patients vs. two of six of medically treated patients (p= .048).

CONCLUSION

ATBAD is associated with increased FDG uptake in the acute phase primarily in the descending aorta, but also involving the aortic arch and ascending aorta, indicating an inflammatory response in the whole aorta. Inflammation subsides early in the ascending aorta and arch (three months), whereas it stabilised later in the descending aorta (nine to 12 months). MRI signs of inflammation were more frequent in patients who later needed surgical treatment and merit further investigation.

Gore TAG thoracic branch endograft for treatment of a subacute type B aortic dissection complicated by rupture

An 80-year-old man presented with a subacute zone 3-5 type B aortic dissection complicated by rupture and visceral and lower extremity malperfusion. He underwent emergent zone 2 repair with a Gore TAG thoracic branch endograft with inclusion of the left subclavian artery for a dominant left vertebral artery. The patient's postoperative course was uncomplicated. Type B aortic dissections can be anatomically complex, and rupture is a rare complication in the subacute phase. We report the novel use of a Gore TAG thoracic branch endograft for the management of type B aortic dissection complicated by rupture and demonstrate its feasibility for patients with type B aortic dissection complicated by rupture.

Timing of Intervention for Aortic Intramural Hematoma

Intramural hematoma (IMH) is one of the acute aortic syndromes along with acute aortic dissection and penetrating aortic ulcer. The three conditions can occur alone or in combination with overlapping presentation. Medical, open surgical, and endovascular treatment is tailored depending on clinical presentation, timing, and location within the aorta. Among patients who present with acute IMH affecting the ascending aorta (Type A), urgent open surgical repair is considered the primary line of treatment in patients who are suitable candidates and unstable. The management of IMH in the descending aorta and aortic arch (Type B) is similar to that applied to treat acute dissections in the same segment. Medical treatment with sequential imaging is recommended in patients with uncomplicated course, and endovascular repair is indicated in patients with rupture, persistent pain, end-organ ischemia, or rapid aortic enlargement. This review discusses the ideal timing for treatment of IMH.

An atypical presentation of aortic dissection: echocardiography for accurate detection

BACKGROUND

Aortic dissection (AD) is a relatively rare but dreadful illness, often accompanied by severe, sharp (or 'tearing') back pain or anterior chest pain, as well as acute hemodynamic compromise. Painless dissection has also been reported in rare cases. Echocardiography has become the most commonly used imaging test for evaluating cardiovascular disease and, thus, plays an important role in aortic disease diagnosis and follow-up.

CASE PRESENTATION

This paper presents the case of a 63-year-old female presenting a chronic cough for more than 30 days, accompanied by chest pain radiating to the left scapula, a history of chronic hypertension, and recent chest x-ray findings of mediastinal mass on the upper left of the aortic knob. Transthoracic echocardiography (TTE) shows a clear image of a dissection flap on the ascending aorta and abdominal aorta, with a false lumen that is larger than the true lumen and filled with intramural thrombus. A transesophageal echocardiography (TOE) examination performed later shows a clear entry tear near the sinuses of Valsalva directly above the ostium of the right coronary artery (RCA). The patient was diagnosed with AD Stanford A de Bakey Type 1. Computed tomography (CT) focusing on the thoracoabdominal aorta and coronary artery was ordered upon suspicion of RCA ostium obstruction by the dissection flap and to further direct the surgical management. However, later on, the patient refused to undergo surgery, opting instead for conservative medical therapy.

CONCLUSION

The diagnosis of AD is challenging. Our case emphasizes the vital role of TTE in diagnosing AD, particularly in patients with atypical symptoms in which the diagnosis of AD might not be considered. Such missed AD diagnoses can lead to precarious outcomes.

18F-Sodium Fluoride Positron Emission Tomography and Computed Tomography in Acute Aortic Syndrome

BACKGROUND

Acute aortic syndrome is associated with aortic medial degeneration. 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) detects microscopic tissue calcification as a marker of disease activity.

OBJECTIVES

In a proof-of-concept study, this investigation aimed to establish whether 18F-NaF PET combined with computed tomography (CT) angiography could identify aortic medial disease activity in patients with acute aortic syndrome.

METHODS

Patients with aortic dissection or intramural hematomas and control subjects underwent 18F-NaF PET/CT angiography of the aorta. Aortic 18F-NaF uptake was measured at the most diseased segment, and the maximum value was corrected for background blood pool activity (maximum tissue-to-background ratio [TBRmax]). Radiotracer uptake was compared with change in aortic size and major adverse aortic events (aortic rupture, aorta-related death, or aortic repair) over 45 ± 13 months.

RESULTS

Aortic 18F-NaF uptake co-localized with histologically defined regions of microcalcification and elastin disruption. Compared with control subjects, patients with acute aortic syndrome had increased 18F-NaF uptake (TBRmax: 1.36 ± 0.39 [n = 20] vs 2.02 ± 0.42 [n = 47] respectively; P < 0.001) with enhanced uptake at the site of intimal disruption (+27.5%; P < 0.001). 18F-NaF uptake in the false lumen was associated with aortic growth (+7.1 mm/year; P = 0.011), and uptake in the outer aortic wall was associated with major adverse aortic events (HR: 8.5 [95% CI: 1.4-50.4]; P = 0.019).

CONCLUSIONS

In patients with acute aortic syndrome, 18F-NaF uptake was enhanced at sites of disease activity and was associated with aortic growth and clinical events. 18F-NaF PET/CT holds promise as a noninvasive marker of disease severity and future risk in patients with acute aortic syndrome. (18F Sodium Fluoride PET/CT in Acute Aortic Syndrome [FAASt]; NCT03647566).

Red Blood Cell Distribution Width: A Prognostic Marker in Patients With Type B Aortic Dissection Undergoing Endovascular Aortic Repair

Background

Red blood cell distribution width (RDW) is associated with cardiovascular mortality. However, the relationship between preoperative RDW and outcomes after thoracic endovascular aortic repair (TEVAR) in type B aortic dissection (TBAD) remains to be determined.

Methods

We review the records of 678 patients with TBAD and treated with TEVAR in three centers. Patients were divided into two groups according to the admission RDW cut-off by receiver operating characteristic curve analysis [≤13.5% (n = 278) and >13.5% (n = 400)]. The association between RDW and long-term mortality was evaluated using Cox survival analysis. Additionally, we used general additive models (GAM) with restricted cubic splines (RCS) to explore non-linear relationships between RDW and outcomes.

Results

Subjects with a high RDW had significantly higher in-hospital mortality rates (1.4 vs. 4.3%, P = 0.038). A total of 70 subjects died after a median follow-up period of 3.3 years. Kaplan–Meier analysis showed that subjects with an RDW >13.5% had worse survival rates than those with lower RDW values (P < 0.001). Multivariate Cox proportional hazard modeling revealed that an RDW >13.5% was an independent predictor of long-term mortality (adjusted HR = 2.27, P = 0.006). Also, we found that there was a non-linear relationship between RDW and mortality from RCS, and RDW of 13.5% might be an inflection point to distinguish the long-term mortality risk of TBAD patients.

Conclusion

As an inexpensive and routinely measured parameter, RDW holds promise as a novel prognostic marker in patients with TBAD receiving TEVAR. We found that an RDW >13.5% on admission was independently associated with increased long-term mortality.

Imaging and Surveillance of Chronic Aortic Dissection: A Scientific Statement From the American Heart Association

All patients surviving an acute aortic dissection require continued lifelong surveillance of their diseased aorta. Late complications, driven predominantly by chronic false lumen degeneration and aneurysm formation, often require surgical, endovascular, or hybrid interventions to treat or prevent aortic rupture. Imaging plays a central role in the medical decision-making of patients with chronic aortic dissection. Accurate aortic diameter measurements and rigorous, systematic documentation of diameter changes over time with different imaging equipment and modalities pose a range of practical challenges in these complex patients. Currently, no guidelines or recommendations for imaging surveillance in patients with chronic aortic dissection exist. In this document, we present state-of-the-art imaging and measurement techniques for patients with chronic aortic dissection and clarify the need for standardized measurements and reporting for lifelong surveillance. We also examine the emerging role of imaging and computer simulations to predict aortic false lumen degeneration, remodeling, and biomechanical failure from morphological and hemodynamic features. These insights may improve risk stratification, individualize contemporary treatment options, and potentially aid in the conception of novel treatment strategies in the future.

Thoracic endovascular repair of chronic type B aortic dissection: a systematic review

BACKGROUND

At present, the optimal management strategy for chronic type B aortic dissection (CTBAD) remains unknown, as equipoise remains regarding medical management versus endovascular treatment versus open surgery. However, the results over recent years of thoracic endovascular aortic repair (TEVAR) in CTBAD appear promising. The aim of this systematic review was to provide a comprehensive analysis of the available data reporting outcomes and survival rates for TEVAR in CTBAD.

METHODS

Electronic searches of six databases were performed from inception to April 2021. All studies reporting outcomes, specifically 30-day mortality rates, for endovascular repair of CTBAD were identified. Relevant data were extracted, and a random-effects meta-analysis of proportions or means was performed to aggregate the data. Survival data were pooled using data derived from original Kaplan-Meier curves, which allows reconstruction of individual patient data.

RESULTS

Forty-eight studies with 2,641 patients were identified. Early (<30 days) all-cause and aortic-related mortality rates were low at 1.6% and 0.5%, respectively. Incidence of retrograde type A dissection in the post-operative period was only 1.4%. There were also low rates of cerebrovascular accidents and spinal cord injury (1.1% and 0.9%, respectively). Late follow-up all-cause mortality was 8.0%, however, late aortic-related mortality was only 2.4%. Reintervention rates were 10.1% for endovascular and 6.7% for surgical reintervention. Pooled rates of overall survival at 1-, 3-, 5- and 10-year were 91.5%, 84.7%, 77.7% and 56.3%, respectively.

CONCLUSIONS

The significant heterogeneity in the available evidence and absence of consensus reporting standards are important considerations and concern when interpreting the data. Evaluation of the evidence suggests that TEVAR for CTBAD is a safe procedure with low rates of complications. However, the optimal treatment strategy for CTBAD remains debatable and requires further research. Evidence from high-quality registries and clinical trials are required to address these challenges.

Aortic-related Readmission after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection Patients: A Single-center Retrospective Study

OBJECTIVES

This study aimed to investigate the characteristics of and risk factors for aortic-related readmission after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD).

METHODS

Data from TBAD patients who underwent TEVAR from 2009-2018 at a Chinese tertiary center were retrospectively collected and analyzed. Enrolled patients were categorized into two groups according to whether aortic-related readmission occurred during follow-up, which was defined as hospitalization at least once after the initial procedure due to events that were related to or caused by aortic dissection or the initial procedure.

RESULTS

A total of 1 288 TBAD patients were enrolled, and 99 patients experienced aortic-related readmissions (7.7%), among whom chronic patients had the highest readmission rate (9.8%). The yearly proportion of readmission during the first year after initial procedure revealed a decreasing trend with a -9.7% annual percentage change. Seventy-one patients underwent reintervention (71.7%). Distal aneurysmal degeneration (43.7%) and distal stent graft-induced new entries (32.4%) were two major causes for reintervention. Fourteen patients in the reintervention subgroup underwent a second reintervention (19.7%). In-hospital mortality was 1.0% during the readmission and 14.3% during the second readmission. The overall survival was comparable between two groups (p=.93).

CONCLUSIONS

This study highlighted the importance of surveillance after initial procedure for TBAD patients with potential risk factors for aortic-related readmission, and the predisposition of patients with reintervention to multiple readmissions deserves attention.

A Systematic Review and Meta-analysis of the Incidence of Acute Aortic Dissections in Population-Based Studies

OBJECTIVE

To perform a systematic-review and meta-analysis of all population-based studies reporting on incidence of acute aortic dissections.

METHODS

We searched MEDLINE, EMBASE, CENTRAL and Open Grey databases from inception to August 2020 for population-based studies reporting on the incidence of AAD. A systematic review was conducted following the PRISMA guidelines using a registered protocol (CRD42020204007). Data was pooled using a random-effects model of proportions using Freeman-Tukey double arcsine transformation. The main outcome was the incidence of AAD. Secondary outcomes were incidence type A aortic dissections (TAAD) and type B aortic dissections (TBAD); incidence of aortic dissection repair and medical management and incidence of in-hospital mortality. In addition, we estimated the proportion of aortic dissection repair and mortality (in hospital, overall and specific mortality according to sub-type) among patients with AAD.

RESULTS

Thirty-three studies were included. The pooled incidence of AADs was 4.8 per 100 000 individuals/year (95%CI: 3.6; 6.1). Incidence of TAAD was 3.0 per 100 000/year (95%CI: 1.8; 4.4) and incidence of TBAD was 1.6 per 100 000/year (95%CI: 1.1; 2.2). The incidence of AAD needing repair was 1.4 per 100 000/year (95%CI: 1.0; 2.0) [1.4 (95%CI: 1.2; 1.7) for TAAD and 0.4 (95%CI: 0.2; 0.7) for TBAD]. Incidence of medically managed AAD was 3.4 per 100 000/year (95%CI: 2.4; 4.5). Incidence of in-hospital death due to AAD was 1.3 per 100 000 individuals/year (95%CI: 0.9; 1.9); 1.0 (95%CI: 0.6; 1.4; I²97%) for TAAD and 0.3 for TBAD (95%CI: 0.2; 0.4; I²96%).

CONCLUSION

A global estimate regarding the incidence rate of acute aortic dissections was achieved. Incidence of acute aortic dissection varied significantly between study designs and geographical regions. More accurate information on acute aortic dissection epidemiology is crucial for public-health decisions, clinical understanding, and healthcare management.

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

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

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.

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.

TEVAR Stent to the False Lumen of a Chronic Type B Aortic Dissection With Aneurysmal Dilatation, When no Other Options Are Left

We report a case of a 72 years-old male referred to us with a 2-year history of an enlarging aortic aneurysm secondary to a chronic Type B aortic dissection and a complete occlusion of the true lumen in the thoracic and abdominal aorta except at the level of visceral arteries origins. Several attempts to recanalize the true lumen was not successful. Because of the patient's high risk for an open repair and the normal size of his thoracic aorta proximal to the celiac artery, we deployed the TEVAR stent to the false lumen to prevent aneurysmal enlargement and rupture. The operation was successful, and the patient recovered without complications and with complete exclusion of the aneurysm on two years follow up.

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.

Long-term Results of Thoracic Endovascular Aortic Repair for Type B Aortic Dissection and Risk Factors for Survival

Purpose: To compare characteristics of acute, subacute, and chronic type B aortic dissection and their influence on long-term results of thoracic endovascular aortic repair (TEVAR). Materials and Methods: In a single-center, retrospective cohort study, 314 patients (median age 52 years; 244 men) with acute (n=165), subacute (n=115), or chronic (n=34) type B aortic dissection underwent TEVAR between January 2009 and December 2013. Patient demographics, risk factors, and imaging characteristics were compared among the groups. Univariable and multivariable Cox regression analyses were performed to identify any factors influencing survival. Results: The acute and subacute patients exhibited more complications at presentation than chronic patients. However, the chronic patients exhibited more aneurysmal dilatation (p<0.001) and true lumen collapse (p<0.001). Over a mean follow-up of 68.1±22.9 months (range 2–108), subacute patients showed a lower reintervention rate (3.6% vs 12.1% vs 12.1%, p=0.045), a lower major complication rate (14.4% vs 33.1% vs 27.3%, p=0.002), and better cumulative overall survival (p=0.03) than the acute and chronic groups, respectively. Furthermore, acute patients developed more stent-graft–induced distal erosion (p=0.017) and retrograde type A dissection (RTAD) (p=0.036), whereas chronic patients had less aortic remodeling in the stented segment (p<0.001), distal thoracic aorta (p<0.001), and abdominal aorta (p=0.047). Finally, multivariable analysis demonstrated age >52 years, visceral malperfusion, and RTAD as independent factors influencing overall survival; aneurysmal dilatation, rupture/impending rupture, and RTAD were independent factors influencing aorta-specific survival. Conclusion: Acute and subacute patients had increased risks of rupture and complications at presentation, whereas chronic patients had increased risks for aneurysmal dilatation. From a long-term perspective, the subacute phase might be an optimal time for TEVAR in cases of type B aortic dissection that do not need emergent interventions. The risk factors influencing survival should be identified, carefully managed, and possibly prevented.

Endovascular Therapy for Chronic Type B Aortic Dissection

Objectives: Endovascular repair of the thoracic aorta (TEVAR) represents a therapeutic option for type B aortic dissection. However, the optimal timing for TEVAR is controversial. We examined the outcomes of TEVAR for chronic type B dissection and reviewed aortic morphology using pre- and postoperative CT scan images.

Methods: Between 2012 and 2017, 12 patients underwent TEVAR for chronic type B dissection at our institution. We retrospectively reviewed the clinical and operative data including CT scan images, comparing the values between early group (5 cases, 3 months to 1 year from initial dissection) and late group (7 cases, more than 1 year from initial dissection).

Results: There were no paraplegia, stroke, and death in our cohort. There was no difference in degree of the aortic remodeling between two groups.

Conclusions: Outcomes after TEVAR for chronic type B aortic dissection were favorable. Aortic remodeling could be obtained in selected patients by closing an entry with TEVAR procedure. (This is a translation of Jpn J Vasc Surg 2018; 27: 281–287.)

Retrospective Comparative Analysis of Computed Tomography Findings of Acute and Chronic Aortic Dissections and Intramural Hematomas

PURPOSE

The objective of this study was to assess the reliability of ancillary imaging findings in distinguishing acute from chronic aortic dissection (AD) and intramural hematoma (IMH) using computed tomography angiography (CTA).

MATERIALS AND METHODS

Two radiologists specializing in cardiothoracic and vascular imaging reviewed paired CTAs of patients with AD or IMH who underwent CTA in the acute (within 24 h of presentation) and chronic settings. The radiologists were blinded to the temporal order of the CTAs. Minimum and maximum flap thicknesses and presence or absence of pleural effusion, pericardial effusion, mediastinal hematoma or fat standing, and mediastinal lymphadenopathy were recorded.

RESULTS

Patients included 25 male individuals and 13 female individuals with a mean age of 59 years (range: 34 to 87 y). The group included 29 AD and 9 IMH cases. The median interval between the paired CTs was 542 days (range: 100 to 2533 d). Respectively, the mean minimum flap thicknesses in the acute and chronic AD were 1.3 and 1.4 mm (P=0.3), and the mean maximum flap thicknesses were 2.7 and 2.9 mm (P=0.29). The incidences of ancillary findings in acute and chronic AD and IMH were as follows: pleural effusion (55% vs. 37%, P=0.143), pericardial effusion (8% vs. 11%, P=1.0), lymphadenopathy (47% vs. 47%, P=1.0), and periaortic fat stranding (87% vs. 76%, P=0.344).

CONCLUSIONS

Ancillary CT imaging findings traditionally ascribed to acute AD and IMH are also often found in the chronic setting and are not reliable indicators of acuity. Flap thickness in AD may not be a reliable imaging indicator of acuity of AD.

Assessing Aortic Remodeling after Thoracic Endovascular Aortic Repair (TEVAR) in DeBakey IIIb Aortic Dissection: A Retrospective Study

PURPOSE

This study analyzed the different levels of aortic remodeling in patients with DeBakey IIIb aortic dissection (AD) after thoracic endovascular aortic repair (TEVAR) at a single center.

METHODS

In all, 66 patients with DeBakey IIIb AD who underwent TEVAR in the acute (Group A) or subacute phase (Group SA) from January 2012 to October 2016 were included in the study. The change in aortic lumen (A), true lumen (TL), false lumen (FL), and true lumen index (TLi) at different levels were analyzed.

RESULTS

There was no statistically significant difference in the clinical information and morphologic imaging findings in Groups A and SA. At proximal levels (levels A-C), there was no difference in aortic remodeling parameters, that is, increased TL, decreased FL, and increased TLi at levels B and C and stable A at levels A-C, in both groups. Moreover, the above parameters were illustrated using a box-and-whisker plot, which revealed the unstable acute phase by the larger distribution interval and the median and abnormal values of the right skew distribution in Group A.

CONCLUSION

Postoperative surveillance is important for patients of both acute and subacute AD.

Indications for Thoracic EndoVascular Aortic Repair (TEVAR): A Brief Review

The utility of Thoracic EndoVascular Aortic Repair (TEVAR) continues to progress at a very rapid rate. Initially implemented for the treatment of thoracic aortic aneurysms, TEVAR has evolved to treat a variety of aortic pathologies and reduce overall morbidity and mortality rates compared with traditional open surgical repair. Given the rapidly evolving nature of endovascular thoracic intervention, we hereby briefly review the current literature on the evolving applications of TEVAR. TEVAR continues to rapidly evolve and is being applied to a growing number of aortic pathologies. Given the perioperative, short- and mid-term morbidity and mortality rates, TEVAR is quickly surpassing traditional open surgical intervention as the ideal procedure for patients undergoing intervention of the descending thoracic aorta and applicability to ascending and arch pathologies is being explored. However, as more data becomes available TEVAR may be associated with higher rates of reoperative requirements. Data remains limited on the long-term efficacy of the intervention and should continue to be investigated.

Temporal and Morphological Patterns Predict Outcome of Endovascular Repair in Acute Complicated Type B Aortic Dissection

OBJECTIVES

The aim was to analyse early and late outcomes in patients undergoing thoracic endovascular aortic repair (TEVAR) for acute or subacute non-traumatic type B aortic dissection (TBAD), with the particular aims of identifying prognostic morphological predictors, and to assess the magnitude of the impact of the timing of TEVAR.

METHODS

This was a retrospective, two centre, population based consecutive case series. The study group consisted of all the 53 patients undergoing TEVAR for complicated TBAD in Stockholm during the 12 year period 2004-2015. Demographic data, risk factors, operative, and outcome variables were registered and analysed. The CT scans were thoroughly retrospectively examined.

RESULTS

Nearly half (24 patients; 45%) underwent TEVAR within 48 h of the onset of the initial symptoms, another 20 within 2 weeks, and nine in the subacute phase (15-90 days). The median age was 63 years (range 32-88) and 20 patients (38%) were women. The 30 day mortality was 17% (nine patients). Eight of these nine patients were treated within the first 48 h; urgent intervention (0-48 h) was associated with increased mortality (crude OR 14.0; 95% CI 1.6-122). All the nine patients had a false lumen area (FLA) at the level of the tracheal bifurcation exceeding 50% of the aortic cross sectional area at that segment, a finding significantly associated with increased mortality (p = .04), with a 25% 30 day mortality if the FLA > 50% (n = 36) at that segment, but 0% if the FLA was <50%. Overall the one year survival was 79% and five year survival 65%.

CONCLUSIONS

All the early deaths demonstrated a FLA >50% of the total aortic cross sectional area at the level of the tracheal bifurcation. Patients needing urgent TEVAR had markedly worse outcome. The first finding may become an additional tool for future risk stratification.

Cerebrovascular injuries found in acute type B aortic dissections are associated with blood pressure derangements and poor outcome

OBJECTIVE

Cerebrovascular injury (CVI) is a recognized but underappreciated complication of acute type B aortic dissection (ATBAD). This study was performed to determine risk factors for CVI associated with ATBAD and, in particular, the possible contributory role of aggressive anti-impulse therapy.

METHODS

A retrospective review of all patients presenting to a tertiary medical center with an ATBAD between January 2003 and October 2012 was conducted. All CVIs were adjudicated by a vascular neurologist and assigned a probable cause. The initial intensity of anti-impulse therapy was defined as the difference in mean arterial pressure (ΔMAP) from presentation to subsequent admission to the intensive care unit.

RESULTS

A total of 112 patients were identified. The average age was 61 years; 64% were male, and 59% were African American. Twenty patients required operative intervention (14 thoracic endovascular aortic repairs and 6 open). CVI occurred in 13 patients (11.6%): 9 were hypoperfusion related (6 diffuse hypoxic brain injuries and 3 watershed infarcts), 2 were procedure related (both thoracic endovascular aortic repairs), 1 was an intracranial hemorrhage on presentation, and 1 was a probable embolic stroke on presentation. CVI patients had demographics and comorbidities comparable to those of the non-CVI patients. CVI was associated with operative intervention (54% vs 13%; P = .002). Thirty-day mortality was significantly higher in CVI patients (54% vs 6%; P < .001). Patients who suffered a hypoperfusion brain injury had a higher MAP on presentation to the emergency department (142 mm Hg vs 120 mm Hg; P = .034) and a significantly greater reduction in MAP (ΔMAP 49 mm Hg vs 15 mm Hg; P < .001) by the time they reached the intensive care unit compared with the non-CVI patients.

CONCLUSIONS

In our series, CVI in ATBAD is more frequent than previously reported and is associated with increased mortality. The most common causes are related to cerebral hypoperfusion. Higher MAP on presentation and greater decline in MAP are associated risk factors for hypoperfusion-related CVI. A less aggressive approach to lowering MAP in ATBAD warrants further study in an attempt to reduce CVI in ATBAD.

Incidence and risk factors of recurrent pain in acute aortic dissection and in-hospital mortality

BACKGROUND

We investigated the prevalence of recurrent pain and its relationship with in-hospital mortality in acute aortic dissection (AAD).

PATIENTS AND METHODS

Between 2011 and 2016, 234 AAD patients were selected. Recurrent pain was defined as a mean of VAS > 3, within 48 hours following hospital admission or before emergency operation. Patients with and without recurrent pain were divided into group I and group II, respectively into type A AAD and type B AAD patients. Our primary outcome was in-hospital mortality.

RESULTS

The incidence of recurrent pain was 24.4 % in AAD patients. Incidence of recurrent pain was higher in type A AAD patients than type B AAD patients (48.9 vs. 9.6 %). Overall in-hospital mortality was 25.6 %. Type A AAD had a higher in-hospital mortality than type B AAD patients (47.7 vs. 12.3 %). Group I had significantly higher in-hospital mortality than group II (type A: 79.1 vs. 17.8 %; type B: 57.1 vs. 7.6 %, all P < 0.001), as was the case with medical managed patients (type A: 72.1 vs. 13.3 %; type B: 35.7 vs. 2.3 %, all P < 0.001). Logistic regression analysis showed that use of one drug alone and waist pain were predictive factors for recurrent pain in type A AAD and type A AAD patients, respectively (OR 3.686, 95 % CI: 1.103~12.316, P = 0.034 and OR 14.010, 95 % CI: 2.481~79.103, P = 0.003). Recurrent pains were the risk factors (type A: OR 11.096, 95 % CI: 3.057~40.280, P < 0.001; type B: OR 14.412, 95 % CI: 3.662~56.723, P < 0.001), while invasive interventions were protective (type A: OR 0.133, 95 % CI: 0.035~0.507, P < 0.001; type B: OR 0.334, 95 % CI: 0.120~0.929, P = 0.036) for in-hospital mortality in AAD patients.

CONCLUSIONS

Approximately one-fourth of AAD patients presented with recurrent pains, which might increase in-hospital mortality. Thus, interventional strategies at early stages are important.

Aortic remodelling after thoracic endovascular aortic repair for acute and subacute type B aortic dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) in the current era has gained widespread acceptance as the modality of choice for the treatment of complicated aortic dissection (AD). However, reports on clinical results of TEVAR treatment of AD patients are mainly comparisons and analyses of results between patients in the acute and chronic phases, few reports have described the postoperative aortic remodelling of patients with subacute AD after TEVAR. The aim of this study was to investigate aortic remodelling after TEVAR in acute and subacute Stanford type B AD patients.

METHODS

The clinical data of 38 Stanford type B AD patients who received TEVAR treatment in our hospital between July 2012 and December 2017 were retrospectively analysed. The maximum diameters of the aorta, the mean diameters of the true lumens (TLs) and the false lumens (FLs) of the aorta in the dissection range before and after TEVAR treatment were measured. All diameters between different groups or in the same group before and after therapy were compared using nonparametric tests. Count data were examined using the χ² test.

RESULTS

The 38 patients were 31.0-82.0 years old with a mean age of 57.0±11.0 years, including 31 men and 7 women, with 22 patients in the acute phase and 16 patients in the subacute phase. Among the 38 patients included in this study, 7 (18.4%) patients had endoleaks after treatment. No perioperative deaths occurred. Analyses of computed tomography angiography measurement results showed that the baseline maximum diameters of the aorta, TLs and FLs before TEVAR between the acute and subacute groups were not significantly different (P=0.193, P=0.301 and P=0.067, respectively). After TEVAR treatment, the maximum diameters of the aorta and the diameters of the FLs were different between the two groups (P=0.005 and P=0.012), but the diameters of the TLs were not (P=0.069). The diameters of the TLs increased, and those of FLs decreased significantly in the acute and subacute groups after TEVAR (P<0.001, P<0.001, P<0.001 and P=0.007, respectively); the maximum diameters of the aorta decreased significantly in the acute group (P<0.001), but they did not change obviously in the subacute group (P=0.121).

CONCLUSIONS

TEVAR offers satisfactory results for the treatment of type B AD. Acute AD may be associated with better aortic remodelling compared to subacute AD after TEVAR.

Type B aortic dissection: new perspectives

Background

Stanford type B aortic dissection is one of the aortic catastrophes with a high mortality and morbidity that needs immediate or delayed treatment, either surgically or endovascularly. This comprehensive review article addresses the current status of open, endovascular and hybrid treatment options for type B aortic dissections with the focus on new therapeutic perspectives.

Methods

Evaluation of currently available evidence based on randomized and registry data and personal experience.

Results

All type B dissections require prompt medical treatment to prevent aortic rupture. Acute complicated dissections are nowadays treated by endografting to reroute blood flow into the true lumen and promote false lumen thrombosis and future aortic remodeling. In acute uncomplicated situations the position of endografting is less clear and should be further delineated; however, on the long run also in these situations endografting might be protective for future aortic catastrophes in certain patient categories. In the chronic dissection with aneurysm formation of the descending thoracic and/or thoracoabdominal aorta, especially in connective tissue disorders, open surgery offers nowadays the best immediate results with long durability. Thoracic endografting plays only a minor role in these circumstances but branched and fenestrated endografting are very promising techniques. Hybrid techniques can offer the solution for high risk patients that are not suitable for open surgery.

Conclusions

Emergent thoracic endografting is the golden standard for all complicated type B dissections while uncomplicated patients with high-risk features might benefit from endovascular repair. Open surgery is limited for chronic post dissection aneurysms. Aortic surveillance is of paramount importance in all situations.

How should we manage type B aortic dissections?

Dissection of the descending aorta is a serious and potentially lethal event. Treatment options consist of medical therapy, open surgical replacement of the affected aorta and thoracic endovascular repair. In acute cases, medical treatment is started initially. When complicated, endovascular repair is generally considered as first choice treatment, except for connective tissue disorders where open surgery remains the standard. In stable, uncomplicated patients with risk factors for future aortic growth pre-emptive endovascular repair should be considered in the sub-acute phase of the dissection. The treatment strategy in chronic dissections is somewhat debated. Long-term results and aortic remodeling of endovascular repair are disappointing and open surgery remains the standard.

Weighted Gene Co-expression Network Analysis Identifies FKBP11 as a Key Regulator in Acute Aortic Dissection through a NF-kB Dependent Pathway

Acute aortic dissection (AAD) is a life-threatening disease. Despite the higher risk of mortality, currently there are no effective therapies that can ameliorate AAD development or progression. Identification of meaningful clusters of co-expressed genes or representative biomarkers for AAD may help to identify new pathomechanisms and foster development of new therapies. To this end, we performed a weighted gene co-expression network analysis (WGCNA) and calculated module-trait correlations based on a public microarray dataset (GSE 52093) and discovered 9 modules were found to be related to AAD. The module which has the strongest positive correlation with AAD was further analyzed and the top 10 hub genes SLC20A1, GINS2, CNN1, FAM198B, MAD2L2, UBE2T, FKBP11, SLMAP, CCDC34, and GALK1 were identified. Furthermore, we validated the data by qRT-PCR in an independent sample set originated from our study center. Overall, the qRT-PCR results were consistent with the results of the microarray analysis. Intriguingly, the highest change was found for FKBP11, a protein belongs to the FKBP family of peptidyl-prolyl cis/trans isomerases, which catalyze the folding of proline-containing polypeptides. In congruent with the gene expression analysis, FKBP11 expression was induced in cultured endothelial cells by angiotensin II treatment and endothelium of the dissected aorta. More importantly we show that FKBP11 provokes inflammation in endothelial cells by interacting with NF-kB p65 subunit, resulting in pro-inflammatory cytokines production. Accordingly, siRNA mediated knockdown of FKBP11 in cultured endothelial cells suppressed angiotensin II induced monocyte transmigration through the endothelial monolayer. Based on these data, we hypothesize that pro-inflammatory cytokines elicited by FKBP11 overexpression in the endothelium under AAD condition could facilitate transendothelial migration of the circulating monocytes into the aorta, where they differentiate into active macrophages and secrete MMPs and other extracellular matrix (ECM) degrading proteins, contributing to sustained inflammation and AAD. Taken together, our data identify important role of FKBP11 which can serve as biomarker and/or therapeutic target for AAD.

Tabernaemontana catharinensis ethyl acetate fraction presents antinociceptive activity without causing toxicological effects in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Tabernaemontana catharinensis (Apocynaceae) is a medicinal plant used for the treatment of painful and inflammatory disorders. Here, we investigated the antinociceptive potential of the ethyl acetate fraction (Eta) from T. catharinensis leaves and assessed its toxic effects in mice to validate its popular use.

MATERIALS AND METHODS

Adult male Swiss mice (30-35g) were used. The Eta antinociceptive effect (200-800mg/kg, oral route (p.o.)) was evaluated in the acetic acid, formalin, capsaicin and tail-immersion tests. Adverse effects were analyzed using rotarod and open-field tests, body temperature, biochemical analysis and gastric lesions assessment. To evaluate the acute (OECD 423) or sub-acute (OECD 407) toxicity of the Eta, it was administered orally at a single (2000mg/kg) or repeated doses (100-400mg/kg/day for 28 days), respectively. Mortality, behavioral changes, biochemical and hematological parameters were evaluated. The Eta effect on cellular viability also was evaluated.

RESULTS

Eta (200-800mg/kg) inhibited the nociception caused by acetic acid (93.9±1.5%), formalin (86.2±10.8%) or capsaicin (75.4±3.3%) without inducing gastric lesions. Moreover, Eta neither altered the body temperature, biochemical parameters, nor forced or spontaneous locomotor activity of mice. The acute administration of the Eta (2000mg/kg) promoted a decrease in blood glucose levels and alanine aminotransferase activity. In the sub-acute toxicity study, Eta increased the aspartate aminotransferase activity (400mg/kg) and platelet distribution width (200mg/kg). Furthermore, Eta did not alter the cellular viability in cortical slices.

CONCLUSIONS

Eta presents antinociceptive effects and mild toxicity in mice. These results support its traditional use as a potential analgesic.

Debate: Whether an endovascular-first strategy is the optimal approach for treating acute mesenteric ischemia

Acute mesenteric ischemia continues to be a life-threatening insult in often-elderly patients with many comorbidities. Recognition and correct diagnosis can be an issue leading to delays in therapy that result in loss of bowel or life, or both. The basic surgical principals in treating acute mesenteric ischemia have long been early recognition, resuscitation, urgent revascularization, resection of necrotic bowel, and reassessment with second-look laparotomies. Endovascular techniques now offer a less invasive alternative, but whether an endovascular-first or open surgery-first approach is preferred in most patients is unclear. Our discussants will attempt to clarify these issues.

Outcomes of Patients With Acute Type B (DeBakey III) Aortic Dissection: A 13-Year, Single-Center Experience

Background—

Aortic dissection remains the most common aortic catastrophe. In the endovascular era, the management of acute type B aortic dissection (ATBAD) is undergoing dramatic changes. The aim of this study is to evaluate the long-term outcomes of patients with ATBAD who were treated at our center over a 13-year period.

Methods and Results—

We reviewed patients with ATBAD between 2001 and 2014, analyzing variables based on status (complicated [c] versus uncomplicated [u]) and treatment modalities. We defined cATBAD as rupture, expansion of diameter on imaging during the admission, persistent pain, or clinical malperfusion leading to a deficit in cerebral, spinal, visceral, renal, or peripheral vascular territories at presentation or during initial hospitalization. Postoperative outcomes were defined as deficits not present before the intervention. Outcomes were compared between the groups by use of Kaplan-Meier and descriptive statistics. We treated 442 patients with ATBAD. Of those 442, 60.6% had uATBAD and were treated medically, and 39.4% had cATBAD, of whom 39.0% were treated medically to 30.0% with open repair, 21.3% with thoracic endovascular aortic repair, and 9.7% with other open peripheral procedures. Intervention-free survival at 1 and 5 years was 84.8% and 62.7% for uATBAD, 61.8% and 44.0% for cATBAD-medical, 69.2% and 47.2% for cATBAD-open, and 68.0% and 42.5% for cATBAD–thoracic endovascular aortic repair, respectively (P=0.001). Overall survival was significantly related primarily to complicated presentation.

Conclusions—

In our experience, early and late outcomes of ATBAD were dependent on the presence of complications, with cATBAD faring worse. Although uATBAD was associated with favorable early survival, late complications still occurred, mandating radiographic surveillance and open or endovascular interventions. Prospective trials are required to better determine the optimal therapy for uATBAD.

Biomechanical Changes After Thoracic Endovascular Aortic Repair in Type B Dissection

Thoracic endovascular aortic repair (TEVAR) has evolved into an established treatment option for type B aortic dissection (TBAD) since it was first introduced 2 decades ago. Morbidity and mortality have decreased due to the minimally invasive character of TEVAR, with adequate stabilization of the dissection, restoration of true lumen perfusion, and subsequent positive aortic remodeling. However, several studies have reported severe setbacks of this technique. Indeed, little is known about the biomechanical behavior of implanted thoracic stent-grafts and the impact on the vascular system. This study sought to systematically review the performance and behavior of implanted thoracic stent-grafts and related biomechanical aortic changes in TBAD patients in order to update current knowledge and future perspectives.