Insights From the International Registry of Acute Aortic Dissection: A 20-Year Experience of Collaborative Clinical Research

Current status in decision making to treat acute type A dissection: limited versus extended repair

Acute type A aortic dissection remains one of the most challenging conditions in aortic surgery. Despite the advancements in the field, the mortality rate still remains high. Though there is a general consensus that the ascending aorta should be replaced, the distal extension of the surgery still remains a controversy. Few surgeons argue for a conservative approach to reduce operative and postoperative morbidity while others considering the problems associated with "downstream problems" support an aggressive approach including a frozen elephant trunk. The cohort in the Indian subcontinent and APAC is far different from the western world. Many factors determine the decision for surgery apart from the pathology of the disease. Economy, availability of the suitable prosthesis, the experience of the surgeon, ease of access to the medical facility all contribute to the decision making to treat acute type A dissection.

Relationship of Platelet Counts and Inflammatory Markers to 30-Day Mortality Risk in Patients with Acute Type A Aortic Dissection

Markers of prothrombotic state and inflammation are associated with the prognosis of patients with acute type A aortic dissection (AAAD). However, it is unclear that the relationship between these biomarkers and their combined impact on risk stratification. The present study evaluated the prognostic value of platelet counts, lymphocyte to neutrophil ratio (LNR), and lymphocyte to monocyte ratio (LMR), alone and in combination. A retrospective analysis of clinical data of 744 AAAD patients was conducted to identify whether these biomarkers were related to the 30-day mortality risk. A Kaplan-Meier analysis and log-rank test were used to compare survival between groups. A Cox hazard regression multivariable analysis was performed for 30-day mortality. Individual biomarker (platelet count, LNR, or LMR) was unable to predict 30-day mortality. However, combinations of all three biomarkers provided additive predictive value over either marker alone, the receiver operating characteristic (ROC) model had a prediction probability of 0.739 when platelet counts, LNR, and LMR were included. Cox hazard regression multivariable analysis showed that combinations of all three biomarkers were the strongest predictor of 30-day mortality (p < 0.021). Combined with these three easily measurable biomarkers at admission, they could help identify AAAD patients with a high risk of 30-day mortality.

An analysis of patients with acute aortic dissection who were transported by physician-staffed helicopter

PURPOSE

The present study aimed to determine whether or not patients with acute aortic dissection (AAD) treated by the staff of a doctor helicopter (DH) service while being transported from the scene or for interhospital transportation obtained a favorable outcome.

METHODS

We retrospectively investigated all patients with AAD who were transported by DH between January 2015 and December 2019 using the registry data of the DH control room of our hospital.

RESULTS

One hundred five cases were enrolled in the present study. All patients were transported within 24 h from the onset. Male patients accounted for 55.2% of the study population, the average age was 71 years and the rate of Stanford A AAD was 51.4%. Regarding transportation, 61.6% of the patients underwent interhospital transportation, and 42.8% were transported to our hospital. All patients underwent drip infusion during transportation and 81.9% of the patients received drugs (e.g., depressors, pain killers and/or antiemetics). Two patients underwent tracheal intubation due to unconsciousness and profound shock with restless state, respectively. The systolic blood pressure after transportation to hospital was significantly higher in comparison to before transportation. No patients suffered cardiac arrest or showed a deterioration of vital signs. All patients were safely transported to the destination.

CONCLUSION

The present study suggests the safety of using a Dr. Heli to transport AAD patients from the scene and for interhospital transportation, even after the onset.

Marfan Syndrome Versus Bicuspid Aortic Valve Disease: Comparative Analysis of Obstetric Outcome and Pregnancy-Associated Immediate and Long-Term Aortic Complications

Pregnancy poses a threat to women with aortopathy. Conclusive data on the obstetric and aortic outcome in this risk collective, especially when it comes to aortic complications in the long term, are still missing. This study offers a comparative analysis of pregnancy-associated outcome in 113 consecutive women with Marfan syndrome or bicuspid aortic valve disease, including 46 ever-pregnant and 37 never-pregnant women with Marfan syndrome, and 23 ever-pregnant and 7 never-pregnant females with bicuspid aortic valve disease. The overall obstetric outcome was comparable between ever-pregnant women with Marfan syndrome and with bicuspid aortic valve disease (p = 0.112). Pregnancy-associated aortic dissection occurred in two women with Marfan syndrome (3%) during a total of 62 completed pregnancies, whereas no single case of aortic event occurred in women with bicuspid aortic valve disease during a total of 36 completed pregnancies (p = 0.530). In the long-term follow-up, aortic dissection occurred in 21% of ever-pregnant women with Marfan syndrome, but in none of the women with bicuspid aortic valve disease (p = 0.022). Proximal aortic surgery was performed with similar frequency in ever-pregnant women with Marfan syndrome and with bicuspid aortic valve disease in the long term (p = 0.252). However, ever-pregnant women with Marfan syndrome were younger when surgery was performed (44 ± 9 vs. 59 ± 7 years; p = 0.041). In Marfan syndrome, long-term growth of the aorta was comparable between ever-pregnant and never-pregnant women. Pregnancy thus exhibited an increased immediate aortic risk only in women with Marfan syndrome, but not in women with bicuspid aortic valve disease. Previous pregnancy did not relate to an increased long-term risk of adverse aortic events in women with Marfan syndrome or with bicuspid aortic valve disease.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Acute Type A Aortic Dissection Repair After Hours: Does It Influence Outcomes?

BACKGROUND

Time of day has been associated with adverse outcomes in certain surgical pathologies. Because acute type A aortic dissection typically mandates immediate repair, relatively little attention has been paid to the potential impact of the day-night timing of the operation itself. We sought to determine whether patients with acute dissection treated during typical working hours demonstrated a difference in outcomes compared with those who required surgery after hours.

METHODS

We undertook a comprehensive review of our prospectively collected database from July 2014 to October 2018. A total of 164 consecutive patients underwent primary repair of an acute type A dissection. Based on the procedure start time, patients were divided into 2 groups: working hours (7 am to 4 pm, Monday to Friday; n = 60), and after hours (all other times, including weekends and holidays; n = 104). We propensity-matched 58 pairs of patients and analyzed perioperative data and short-term clinical outcomes.

RESULTS

Thirty-day mortality for all 164 patients was 10.4% (17 deaths), which was not significantly different between the matched groups (working-hours: 8 deaths [13.8%] versus after hours: 4 deaths [6.9%]; P = .36). Perfusion, cross-clamp, and circulatory arrest times did not differ between groups, nor did the types of aortic repairs performed. Postoperative complications were also comparable, including stroke, reoperation for bleeding, and new-onset renal failure requiring dialysis.

CONCLUSIONS

Thirty-day mortality and major morbidity after acute type A dissection repair are independent of when the operation is performed. Expeditious surgical intervention is recommended for all primary acute type A dissection, irrespective of time of day.

Type A aortic dissection mimicking saddle pulmonary embolism on CT imaging

Type A aortic dissection is an uncommon cause of chest pain that carries a high morbidity and mortality rate. A previous history of hypertension and coronary artery bypass grating (CABG) are recognized risk factors for Type A aortic dissection. We present a case of an elderly man who presents with acute onset chest pain and was found to have an acute ruptured Type A aortic dissection that has a "saddle pulmonary embolism"-like appearance on computed tomography (CT) imaging. We also describe the clinical, laboratory, and radiological workup done leading up to the diagnosis of Type A aortic dissection in the emergency setting.

Effects of IL-22 on cardiovascular diseases

Interleukin-22 (IL-22), which belongs to the IL-10 family, is an alpha helix cytokine specifically produced by many lymphocytes, such as Th1, Th17, Th22, ILCs, CD4+ and CD8+ T cells. In recent years, more and more studies have demonstrated that IL-22 has an interesting relationship with various cardiovascular diseases, including myocarditis, myocardial infarction, atherosclerosis, and other cardiovascular diseases, and IL-22 signal may play a dual role in cardiovascular diseases. Here, we summarize the recent progress on the source, function, regulation of IL-22 and the effects of IL-22 signal in cardiovascular diseases. The study of IL-22 will suggest more specific strategies to maneuver these functions for the effective treatment of cardiovascular diseases and future clinical treatment.

Acute Aortic Dissection With ST Segment Myocardial Infarction Following Masturbation

BACKGROUND

Acute aortic dissection is the most common life-threatening disorder affecting the aorta, and can mimic other disease processes. We describe an unusual presentation of a critically ill patient with initial hematospermia diagnosed with a type A acute aortic dissection.

CASE REPORT

A 68 year old man presented to a community ED after masturbation and report of blood in his ejaculate, followed by rapid development of severe low back, chest and hip pain with shock. ECG showed evidence of ST segment elevation, but suspicion remained high for thoracic or abdominal aortic catastrophe. Bedside ultrasound demonstrated no pericardial effusion, a severely hypokinetic myocardium and a question of fluid in the left perinephric space. Attempts were made to resuscitate the patient, and an ED chest/abdomen/pelvis CT showed a type A acute thoracic aortic dissection. Unfortunately, the patient remained profoundly unstable, with multiple arrests. He was transferred to a tertiary care facility, but expired shortly after arrival. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: An emergency physician needs to be aware of the myriad of presentations of acute aortic dissection. Although hematospermia was felt ultimately to be an incidental symptom, sexual activity may bring about a significant transient increase in blood pressure, which could contribute to sheer force causing aortic injury. Awareness of this trigger and a careful sensitive history may aid the clinician in early diagnosis.

Atypical Hemolytic Uremic Syndrome following Acute Type A Aortic Dissection

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy (TMA)-related disease that manifests as a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury (AKI) and is caused by uncontrolled activation of the complement system. We report the case of a 61-year-old woman with acute type A aortic dissection that subsequently developed into aHUS. The hematologic disorders underlying aHUS improved after treatment with the complement inhibitor eculizumab. It is important to consider aHUS when a patient clinically develops a triad of microangiopathic hemolytic anemia, thrombocytopenia, and an increasing creatinine level following cardiovascular surgery.

A novel risk score on admission for predicting death or need for surgery in patients with acute type A intramural hematoma receiving medical therapy

There has been continuing discussion regarding the treatment strategy for acute type A intramural hematoma (IMH). Most patients are treated conservatively in Japan; hence, predicting fatal events and stratifying risks based on results normally obtained on hospital arrival are important. We aimed to examine the incidences and risk factors of death or need for surgery for acute type A IMH in patients receiving medical treatment and to identify high-risk patients using clinical findings on hospital arrival. From 2011 to 2016, 57 consecutive patients (mean age 72.5 years; male 36.8%) diagnosed with acute type A IMH who were receiving treatment at Shizuoka City Shizuoka Hospital were retrospectively included. Primary endpoint was a composite of cardiovascular death and operation within 1 year after onset. To evaluate sensitivity and specificity of the risk factors and risk score, we estimated the area under the receiver operating characteristic (ROC) curve. Mean follow-up duration was 621 days. Mean systolic blood pressure (SBP) was 129 mmHg. Computed tomography (CT) on arrival showed a mean ascending aorta diameter of 46 mm. Ulcer-like projection (ULP) in the ascending aorta and pericardial effusion (PE) were seen in 33% and 42% of cases, respectively. Twenty-eight patients (49.1%) reached the primary endpoint (cardiovascular death, 7 cases [12.3%]; operation, 21 cases [36.8%]). In univariate analysis of admission values, the primary endpoint group had significantly lower SBP (113.0 ± 28.5 vs 144.3 ± 33.5 mmHg), higher ascending aorta diameter (49.5 ± 8.1 vs 43.6 ± 5.9 mm), and higher frequency of ULP (53.8% vs 13.8%) and PE (58.6% vs 25.0%) than the event-free group. Multivariate analysis showed that ULP on admission CT was a significant predictor of the primary endpoint. The risk score was considered using these risk factors. On admission, the primary endpoint could be predicted with 89.7% sensitivity and 75% specificity (area under the ROC curve 0.823) if the patient had ULP and/or > 2 of the following factors: SBP < 120 mmHg, ascending aorta diameter > 45 mm, and PE. SBP and CT findings on arrival were significantly associated with cardiovascular death and the need for surgery in patients with acute type A IMH receiving initial medical therapy. The novel risk score was useful for predicting cardiovascular death and surgery.

Comparative Proteomic Investigation of Plasma Reveals Novel Potential Biomarker Groups for Acute Aortic Dissection

Acute aortic dissection (AAD) is a catastrophic cardiovascular disease with high disability and mortality due to multiple fatal complications. However, the molecular changes of the serum proteome after AAD are not very clear. Here, we performed isobaric tags for relative and absolute quantitation- (iTRAQ-) based comparative proteomic analysis to investigate the proteome profile changes after AAD by collecting plasma samples from 20 AAD patients and 20 controls. Out of the 345 identified proteins, 266 were considered as high-quality quantified proteins (95%confident peptides ≥ 2), of which 25 proteins were accumulated and 12 were reduced in AAD samples. Gene ontology enrichment analysis showed that the 25 AAD-accumulated proteins were enriched in high-density lipoprotein particles for the cellular component category and protein homodimerization acidity for the molecular function category. Protein-protein interaction network analysis showed that serum amyloid A proteins (SAAs), complement component proteins, and carboxypeptidase N catalytic chain proteins (CPNs) possessed the key nodes of the network. The expression levels of six selected AAD-accumulated proteins, B2-GP1, CPN1, F9, LBP, SAA1, and SAA2, were validated by ELISA. Moreover, ROC analysis showed that the AUCs of B2-GP1 and CPN1 were 0.808 and 0.702, respectively. Our data provide insights into molecular change profiles in proteome levels after AAD and indicate that B2-GP1 and CPN1 are potential biomarkers for AAD.

Rapid Response in Type A Aortic Dissection: Is There a Decisive Time Interval for Surgical Repair?

Background and Aim of the Study The objective was to evaluate whether there is a decisive time interval for patients to undergo surgery and to analyze if a rapid response in acute aortic dissection type A (AADA) affects patient selection.

Methods In 283 patients undergoing surgery for AADA, median time from onset of initial symptoms to skin incision was 6.9 hours (interquartile range [IQR], 5.0–11.7 hours). Patients were divided into three groups according to median time point of surgery (median ± 3 hours, i.e., 4–10; < 4; and >10 hours).

Results Almost 50% of patients presented in a critical preoperative state at hospital admission. Subanalysis identified patients being operated within 4 hours as an exclusive high-risk cohort (higher rates of preoperative neurologic dysfunction, tamponade, and cardiopulmonary resuscitation). Patients undergoing surgery between 4 and 10 hours showed a significantly better long-term survival (p = 0.021). Surgery within this time interval had a clear protective effect on 30-day mortality (odds ratio [OR]: 0.448. 95% confidence interval [CI]: 0.219–0.915). High age (OR: 1.037; 95% CI: 1.008–1.067), preoperative malperfusion syndrome (OR: 2.802; 95% CI: 1.351–5.811), and preoperative tamponade (OR: 2.621; 95% CI: 1.171–5.866) were factors predicting 30-day mortality.

Conclusion Rapid response in AADA interacts with the natural course of the disease resulting in an overrepresentation of critical patients. While the cohort below 4 hours represents the high-risk patients, time from symptom onset to initiation of surgery should not exceed 10 hours.

Master of the Masquerade: An Atypical Presentation of Acute Aortic Dissection

Acute aortic dissection (AAD) is associated with unacceptably high mortality rate. As such, early diagnosis and aggressive management are essential in order to avoid life-threatening complications. Herein, we report an atypical presentation of AAD and clinical sequelae.

Sex differences in factors associated with post-traumatic stress disorder in acute type A aortic dissection patients

BACKGROUND

Emergency surgery for acute type A aortic dissection (AAAD) is associated with a high risk for posttraumatic stress disorder (PTSD), and the risk factors for PTSD symptoms development in AAAD patients of different sexes remain unclear.

OBJECTIVE

To identify the risk factors for PTSD symptoms separately in the females and males following AAAD.

METHODS

A sample population of 214 patients who had AAAD surgery was recruited. Patients' sociodemographic and disease-specific data were collected during hospitalization.

RESULTS

In this study, PTSD symptoms was present in 22.1% of the male patients and 20.0% of the female patients (P = 0.739). For the male patients with AAAD, PTSD symptoms were significantly positively associated with HADS-D score (P = 0.029), while those with university education and above (P = 0.039), stronger subjective support (P = 0.010) and greater optimism (P = 0.001) had significantly lower possibility for the presence of PTSD symptoms. For the female patients with AAAD, support availability (P = 0.031) was significantly negatively associated with PTSD symptoms while HADS-D score (P = 0.033) was significantly positively associated with PTSD symptoms.

CONCLUSION

Risk factors for PTSD symptoms differ in male patients and female patients following AAAD.

Genetic Deletion of Socs3 in Smooth Muscle Cells Ameliorates Aortic Dissection in Mice

•

Stat3, a major signaling molecule for proinflammatory cytokines including IL-6, was activated both in inflammatory cells and in SMC in the aortic walls of human AD and mouse AD model.

•

SMC-specific deletion of Socs3 enhanced Stat3 activation in SMC, induced moderate proinflammatory response in the aortic walls, and ameliorated AD in mice.

•

SmSocs3-KO aortas showed increases in fibroblasts, adventitial collagen fibers, and tensile strength of the aortic walls.

•

IL-6-stimulated SMC in culture secreted humoral factor(s) that promoted proliferative response of fibroblasts.

Aortic dissection (AD) is the acute destruction of aortic wall and is reportedly induced by inflammatory response. Here we investigated the role of smooth muscle Socs3 (a negative regulator of Janus kinases/signal transducer and activator of transcription signaling) in AD pathogenesis using a mouse model generated via β-aminopropionitrile and angiotensin II infusion. Socs3 deletion specifically in smooth muscle cells yielded a chronic inflammatory response of the aortic wall, which was associated with increased fibroblasts, reinforced aortic tensile strength, and less-severe tissue destruction. Although an acute inflammatory response is detrimental in AD, smooth muscle-regulated inflammatory response seemed protective against AD.

Surgical outcomes of acute type A aortic dissection in patients undergoing cardiopulmonary resuscitation

OBJECTIVES

The surgical indications for acute type A aortic dissection (AAAD) in patients in cardiopulmonary arrest remain controversial. Outcomes of AAAD for patients who underwent cardiopulmonary resuscitation (CPR) were evaluated.

METHODS

Between 2004 and 2018, of the 519 patients who underwent AAAD repair, 34 (6.6%) required CPR before or on starting AAAD repair. The patients were divided into 2 groups, survivors (n = 13) and nonsurvivors (n = 21), to compare the early operative outcomes, including mortality and neurological events.

RESULTS

The major cause of cardiovascular collapse requiring CPR was aortic rupture/cardiac tamponade (n = 21 [61.8%]), followed by coronary malperfusion (n = 12 [35.3%]) and acute aortic valve regurgitation (n = 3 [8.8%]). There were 3 (23.1%) patients in the survivors group and 11 (52.4%) in the nonsurvivors group who required ongoing CPR at the beginning of AAAD repair (P = .039). Of these patients, 1 survivor and 6 nonsurvivors could not achieve return of spontaneous circulation after pericardiotomy (P = .045). Although the duration from onset or arrival to the operating room was similar (P = .35 and P = .49, respectively), overall duration of CPR was shorter in survivors (10 minutes [range, 7.5-16 minutes] vs 16.5 minutes [range, 15-20 minutes]; P = .044). All survivors without any neurological deficits showed return of spontaneous circulation after pericardiotomy. Multivariate regression modeling showed that CPR duration >15 minutes was a significant risk factor for in-hospital mortality (P = .0040).

CONCLUSIONS

CPR duration beyond 15 minutes may be a contraindication for AAAD repair. Moreover, we should reconsider surgery for patients who cannot achieve return of spontaneous circulation after pericardiotomy.

Is the Natural Anatomical Evolution of Type B Intramural Hematomas Reliable to Identify the Patients at Risk of Aneurysmal Progression?

BACKGROUND

The natural history of type B intramural hematomas is little-known. Aneurysmal progression or an aortic dissection occurs in 15 to 20% of the cases. The study of the natural anatomical evolution could help identify the patients at risk of unfavorable evolution.

METHODS

All the patients monitored for a type B intramural hematoma between 2009 and 2018 were included in this monocentric retrospective study. Computed tomography angiography centerline measurement of diameters was obtained in various points of aortic segmentation on day (D) 0 and at one month (M1). Aortic volumes (lumen, intramural hematoma, and total volume) were calculated. The circulating volume was calculated using the volume rendering method. The volume of the intramural hematoma was measured using a manual section-by-section segmentation tool, and the total volume was obtained by summing up the two preceding volumes. Two groups of patients were compared: group 1 (favorable anatomical evolution) and group 2 (unfavorable anatomical evolution).

RESULTS

Between January 2008 and August 2018, 25 patients were managed for a type B intramural hematoma in our center. After an average follow-up of 15.5 months (1-52), 13 patients (52%) presented a favorable evolution and 12 (48%) an unfavorable evolution. At M1, a significant increase of the luminal diameters (37 mm vs. 32 mm; P < 0.01) and a significant reduction in the longitudinal extension (19 mm vs. 26 mm; P < 0.01) were observed. The maximum aortic diameter evolved significantly between D0 and M1 in the unfavorable evolution group (49 mm vs. 44 mm, respectively; P = 0.038). Such a difference was not found in the favorable evolution group (37.4 vs. 37.1, respectively; P = 0.552). An overall significant reduction in the total aortic volume (166 cm³ vs. 219 cm³; P < 0.01), the circulating volume (124 cm³ vs. 145 cm³; P = 0,026), and the volume of the hematoma (42 cm³ vs. 39 cm³; P < 0.01) was observed. The circulating volume decreased significantly between D0 and M1 in the favorable evolution group (110 cm³ vs. 135 cm³; P = 0.05), whereas no difference was noted in the unfavorable group (142 cm³ vs, 157 cm³; P = 0.24).

CONCLUSIONS

The progression of the maximum aortic diameter and of the circulating volume after one month of follow-up could be predictive factors of the poor long-term evolution of type B intramural hematomas.

IL-5 overexpression attenuates aortic dissection by reducing inflammation and smooth muscle cell apoptosis

BACKGROUND

As an inflammation-related cytokine, interleukin (IL)-5 has been reported to be involved in the development of cardiovascular diseases, such as chronic heart failure and atherosclerosis. However, the role of IL-5 in acute aortic dissection (AAD) has barely been explored.

METHODS

Aortic tissue samples from normal donors and patients with AAD were collected, and the expression and localization of IL-5 in aortic tissue were analyzed. In addition, a mouse AAD model was established by administering angiotensin II (Ang II) to β-aminopropionitrile (BAPN)-treated mice. Morphological examinations and histopathologic analyses were performed to evaluate the effects of IL-5 overexpression on the occurrence of AAD.

RESULTS

IL-5 expression was significantly decreased in aorta samples from AAD patients compared to those from donors, and macrophages were the main source of IL-5. In addition, IL-5 expression was decreased in plasma and aortic tissue samples from AAD mice. IL-5 overexpression markedly attenuated the occurrence of AAD in mice and produced corresponding decreases in the inflammatory response and cell apoptosis. In cocultures of macrophages and smooth muscle cells (SMCs), IL-5 overexpression in the macrophages significantly reduced Ang II-induced SMC apoptosis.

CONCLUSION

IL-5 overexpression suppresses the development of AAD by reducing inflammation and SMC apoptosis. These results suggest that IL-5 is a potential therapeutic target in AAD.

The application of computational modeling for risk prediction in type B aortic dissection

OBJECTIVE

New tools are urgently needed to help with surgical decision-making in type B aortic dissection (TBAD) that is uncomplicated at the time of initial presentation. This narrative review aims to answer the clinical question, Can computational modeling be used to predict risk in acute and chronic Stanford TBAD?

METHODS

The review (PROSPERO 2018 CRD42018104472) focused on risk prediction in TBAD. A comprehensive search of the Ovid MEDLINE database, using terms related to computational modeling and aortic dissection, was conducted to find studies of any form published between 1998 and 2018. Cohort studies, case series, and case reports of adults (older than 18 years) with computed tomography or magnetic resonance imaging diagnosis of TBAD were included. Computational modeling was applied in all selected studies.

RESULTS

There were 37 studies about computational modeling of TBAD identified from the search, and the findings were synthesized into a narrative review. Computational modeling can produce numerically calculated values of stresses, pressures, and flow velocities that are difficult to measure in vivo. Hemodynamic parameters-high or low wall shear stress, high pressure gradient between lumens during the cardiac cycle, and high false lumen flow rate-have been linked to the pathogenesis of branch malperfusion and aneurysm formation by numerous studies. Considering the major outcomes of end-organ failure, aortic rupture, and stabilization and remodeling, hypotheses have been generated about inter-relationships of measurable parameters in computational models with observable anatomic and pathologic changes, resulting in specific clinical outcomes.

CONCLUSIONS

There is consistency in study findings about computational modeling in TBAD, although a limited number of patients have been analyzed using various techniques. The mechanistic patterns of association found in this narrative review should be investigated in larger cohort prospective studies to further refine our understanding. It highlights the importance of patient-specific computational hemodynamic parameters in clinical decision-making algorithms. The current challenge is to develop and to test a risk assessment method that can be used by clinicians for TBAD.

Survival and reinterventions after isolated proximal aortic repair in acute type A aortic dissection

OBJECTIVES

Conventional treatment for acute type A dissection is the replacement of the ascending aorta. This study demonstrates the results of a conventional approach with isolated proximal repair combined with concomitant endovascular procedures.

METHODS

Replacement of the ascending aorta with or without an open distal anastomosis was defined as isolated proximal repair and was performed in 562/588 patients between January 2004 and June 2017. A total of 68% were DeBakey type I and 32% were DeBakey type II aortic dissections. Concomitant procedures were thoracic endovascular aortic repair (3.6%); visceral, renal and iliac stents (2%); and peripheral bypasses (1.1%). Mean follow-up was 4.6 ± 3.5 years with a 98% follow-up rate. Early and long-term survival, reintervention rates and risk factors were analysed.

RESULTS

Overall, the in-hospital mortality rate was 10.7%, 5.6% in DeBakey type II and 13% in DeBakey type I aortic dissection (P = 0.008). Risk factors for in-hospital mortality were age [odds ratio (OR) 1.03], chronic obstructive lung disease (OR 3.98), coronary artery disease (OR 2.19), Penn class BC (OR 15.41) and cardiopulmonary bypass time (OR 1.01). The 5- and 10-year survival rates, including in-hospital mortality, were 71% and 54% for type I and 73% and 65% for type II aortic dissection, respectively (P = 0.14). Freedom from reintervention after 5 and 10 years was 96% and 94% for DeBakey type II aortic dissection and 86% and 78% for type I (P < 0.001).

CONCLUSIONS

Combined with concomitant endovascular procedures, good short- and long-term results can be achieved in DeBakey type I and II aortic dissection. The reintervention rate is higher in DeBakey type I but can be managed open and endovascularly with good results.

Aortic Dissection: An Easily Missed Diagnosis when Pain Doesn't Hold the Stage

Case series

Patients: Male, 73-year-old • Female, 70-year-old

Final Diagnosis: Aortic dissection

Symptoms: Paresis

Medication: —

Clinical Procedure: —

Specialty: Neurology

Particle-based computational modelling of arterial disease

Accumulated glycosaminoglycans (GAGs) can sequester water and induce swelling within the intra-lamellar spaces of the medial layer of an artery. It is increasingly believed that stress concentrations caused by focal swelling can trigger the damage and delamination that is often seen in thoracic aortic disease. Here, we present computational simulations using an extended smoothed particle hydrodynamics approach to examine potential roles of pooled GAGs in initiating and propagating intra-lamellar delaminations. Using baseline models of the murine descending thoracic aorta, we first calculate stress distributions in a healthy vessel. Next, we examine increases in mechanical stress in regions surrounding GAG pools. The simulations show that smooth muscle activation can partially protect the wall from swelling-associated damage, consistent with experimental observations, but the wall can yet delaminate particularly in cases of smooth muscle dysfunction or absence. Moreover, pools of GAGs located at different but nearby locations can extend and coalesce, thus propagating a delamination. These findings, combined with a sensitivity study on the input parameters of the model, suggest that localized swelling can alter aortic mechanics in ways that eventually can cause catastrophic damage within the wall. There is, therefore, an increased need to consider roles of GAGs in aortic pathology.

Natural history of descending thoracic and thoracoabdominal aortic aneurysms

OBJECTIVES

Elucidating critical aortic diameters at which natural complications (rupture, dissection, and death) occur is of paramount importance to guide timely surgical intervention. Natural history knowledge for descending thoracic and thoracoabdominal aortic aneurysms is sparse. Our small early studies recommended repairing descending thoracic and thoracoabdominal aortic aneurysms before a critical diameter of 7.0 cm. We focus exclusively on a large number of descending thoracic and thoracoabdominal aortic aneurysms followed over time, enabling a more detailed analysis with greater granularity across aortic sizes.

METHODS

Aortic diameters and long-term complications of 907 patients with descending thoracic and thoracoabdominal aortic aneurysms were reviewed. Growth rates (instrumental variables approach), yearly complication rates, 5-year event-free survival (Kaplan-Meier), and risk of complications as a function of aortic height index (aortic diameter [centimeters]/height [meters]) (competing-risks regression) were calculated.

RESULTS

Estimated mean growth rate of descending thoracic and thoracoabdominal aortic aneurysms was 0.19 cm/year, increasing with increasing aortic size. Median size at acute type B dissection was 4.1 cm. Some 80% of dissections occurred below 5 cm, whereas 93% of ruptures occurred above 5 cm. Descending thoracic and thoracoabdominal aortic aneurysm diameter 6 cm or greater was associated with a 19% yearly rate of rupture, dissection, or death. Five-year complication-free survival progressively decreased with increasing aortic height index. Hazard of complications showed a 6-fold increase at an aortic height index of 4.2 or greater compared with an aortic height index of 3.0 to 3.5 (P < .05). The probability of fatal complications (aortic rupture or death) increased sharply at 2 hinge points: 6.0 and 6.5 cm.

CONCLUSIONS

Acute type B dissections occur frequently at small aortic sizes; thus, prophylactic size-based surgery may not afford a means for dissection protection. However, fatal complications increase dramatically at 6.0 cm, suggesting that preemptive intervention before that criterion can save lives.

Modeling lamellar disruption within the aortic wall using a particle-based approach

Aortic dissections associate with medial degeneration, thus suggesting a need to understand better the biophysical interactions between the cells and matrix that constitute the middle layer of the aortic wall. Here, we use a recently extended "Smoothed Particle Hydrodynamics" formulation to examine potential mechanisms of aortic delamination arising from smooth muscle cell (SMC) dysfunction or apoptosis, degradation of or damage to elastic fibers, and pooling of glycosaminoglycans (GAGs), with associated losses of medial collagen in the region of the GAGs. First, we develop a baseline multi-layered model for the healthy aorta that delineates medial elastic lamellae and intra-lamellar constituents. Next, we examine stress fields resulting from the disruption of individual elastic lamellae, lost SMC contractility, and GAG production within an intra-lamellar space, focusing on the radial transferal of loading rather than on stresses at the tip of the delaminated tissue. Results suggest that local disruptions of elastic lamellae transfer excessive loads to nearby intra-lamellar constituents, which increases cellular vulnerability to dysfunction or death. Similarly, lost SMC function and accumulations of GAGs increase mechanical stress on nearby elastic lamellae, thereby increasing the chance of disruption. Overall these results suggest a positive feedback loop between lamellar disruption and cellular dropout with GAG production and lost medial collagen that is more pronounced at higher distending pressures. Independent of the initiating event, this feedback loop can catastrophically propagate intramural delamination.

Acute type A aortic dissection - a review

Acute type A aortic dissection (ATAAD) is still one of the most challenging diseases that cardiac surgeons encounter. This review is based on the current literature and includes the results from the Nordic Consortium for Acute Type-A Aortic Dissection (NORCAAD) database. It covers different aspects of ATAAD and concentrates on the outcome of surgical repair. The diagnosis is occasionally delayed, and ATAAD is usually lethal if prompt repair is not performed. The dynamic nature of the disease, the variation in presentation and clinical course, and the urgency of treatment require significant attentiveness. Many surgical techniques and perfusion strategies of varying complexity have been described, ranging from simple interposition graft to total arch replacement with frozen elephant trunk and valve-sparing root reconstruction. Although more complex techniques may provide long-term benefit in selected patients, they require significant surgical expertise and experience. Short-term survival is first priority so an expedited operation that fits in with the surgeon's level of expertise is in most cases appropriate.

Predicting in-hospital death in patients with type B acute aortic dissection

The outcome of patients with acute type B aortic dissection (BAAD) is largely dictated by whether or not the case is "complicated." The purpose of this study was to investigate the risk factors leading to in-hospital death among patients with BAAD and then to develop a predictive model to estimate individual risk of in-hospital death.A total of 188 patients with BAAD were enrolled. Risk factors for in-hospital death were investigated with univariate and multivariable logistic regression analysis. Significant risk factors were used to develop a predictive model.The in-hospital mortality rate was 9% (17 of 188 patients). Univariate analysis revealed 7 risk factors to be statistically significant predictors of in-hospital death (P < .1). In multivariable analysis, the following variables at admission were independently associated with increased in-hospital mortality: hypotension (odds ratio [OR], 4.85; 95% confidence interval [CI], 1.12-18.90; P = .04), ischemic complications (OR, 8.24; 95% CI, 1.25-33.85; P < .001), renal dysfunction (OR, 12.32; 95% CI, 10.63-76.66; P < .001), and neutrophil percentage ≥80% (OR, 5.76; 95% CI, 2.58-12.56; P = .03). Based on these multivariable results, a reliable and simple prediction model was developed, a total score of 4 offered the best point value.Independent risk factors associated with in-hospital death can be predicted in BAAD patients. The prediction model could be used to identify the prognosis for BAAD patients and assist physicians in their choice of management.

Aortic endovascular stenting in patients with systemic connective tissue disorders: does the prohibitive dogma still stand tall?

Endovascular repair of thoracic aortic diseases can provide satisfactory outcomes in elective and certain emergency cases involving the descending thoracic and aortic arch. However, open repair remains the gold standard method of aortic root pathologies and certain aortic arch pathologies, such as extended dissection. Nevertheless, the use of endovascular stenting in patients with connective tissue disorders has not been fully explored because the aortic tissues are fragile and the likelihood of keeping the stent in place is low because of its progressive dilatation and subsequent requirement for open repair at a later stage when the stent graft fails. Our brief review focuses on current evidence of the use of stents in patients with connective tissue disorders and whether such practice can be expanded further.

Development of a shear-thinning biomaterial as an endovascular embolic agent for the treatment of type B aortic dissection

False lumen embolisation is a promising treatment strategy in type B aortic dissection (TBAD) but it is limited by the lack of a disease-specific embolic agent. Our aim was to develop a biomaterial that could be delivered minimally-invasively into the TBAD false lumen and embolise the region. We created 24 shear-thinning biomaterials from blends of gelatin, silicate nanoparticles and silk fibroin, and evaluated their suitability as a false lumen embolic agent in TBAD. We determined the stability of mechanical properties by measuring the compressive modulus of samples stored in physiological conditions over a 21 day period. We quantified injectability by measuring the force required to inject each biomaterial through catheters of varying diameter. We also assessed in vitro degradation rates by measuring weight change over 30 days. Finally, we developed an in vitro experimental pulsatile flow setup with two different anatomically-correct TBAD geometries and performed 78 false lumen occlusion experiments under different operating conditions. We found that the compressive moduli changed rapidly on exposure to 37 °C before stabilising by Day 7. A high silicate nanoparticle to gelatin ratio resulted in greater compressive moduli, with a maximum of 117.6 ± 15.2 kPa. By reducing the total solid concentration, we could improve injectability and biomaterials with 8% (w/v) solids required <80 N force to be injected through a 4.0 mm catheter. Our in vitro degradation rates showed that the biomaterial only degraded by 1.5-8.4% over a 30 day period. We found that the biomaterial could occlude flow to the false lumen in 99% of experiments. In conclusion, blends with high silicate nanoparticle and low silk fibroin content warrant further investigation for their potential as false lumen embolic agents and could be a promising alternative to current TBAD repair methods.

Distal Extent of Surgery for Acute Type A Aortic Dissection

Acute type A aortic dissection (TAAD) is a complex disease associated with extremely high morbidity and mortality for which we advocate a coordinated, protocol-driven system of care delivery that begins at patient diagnosis and continues throughout and beyond aortic reconstruction. Essential components of TAAD repair include prompt restoration of true lumen blood flow with obliteration of the false lumen flow, resection of the primary tear sites, restoration of valvular competency, and elimination of any organ malperfusion. This article focuses specifically on extent of repair of the aortic arch and explains our protocols regarding cannulation location and technique, cerebral and distal organ protection strategy, management of the brachiocephalic vessels, and extent of distal aortic reconstruction. We describe an operative strategy for TAAD repair that includes (1) continuous neurocerebral monitoring in all cases, (2) uninterrupted antegrade and/or retrograde cerebral perfusion (depending upon extent of arch repair) during open arch reconstruction, (3) aortic arch replacement technique with or without brachiocephalic vessel replacement using a custom trifurcate graft, and (4) descending aortic stabilization with or without the use of an elephant or frozen elephant trunk (distal stent graft). Our protocol for extent of aortic arch and brachiocephalic reconstruction has been standardized and is predicated on distinct pathoanatomic findings and/or cerebral malperfusion that are outlined.

Intramural hematoma and penetrating ulcer in the descending aorta: differences and similarities

Acute aortic syndromes include a variety of overlapping clinical and anatomic diseases. Intramural hematoma (IMH), penetrating atherosclerotic ulcer (PAU), and aortic dissection can occur as isolated processes or can be found in association. All these entities are potentially life threatening, so prompt diagnosis and treatment is of paramount importance. IMH and PAU affect patients with atherosclerotic risk factors and are located in the descending aorta in 60-70% of cases. IMH diagnosis can be correctly made in most cases. Aortic ulcer is a morphologic entity which comprises several entities-the differential diagnosis includes PAU, focal intimal disruptions (FID) in the context of IMH evolution and ulcerated atherosclerotic plaque. The pathophysiologic mechanism, evolution and prognosis differ somewhat between these entities. However, most PAU are diagnosed incidentally outside the acute phase. Persistent pain despite medical treatment, hemodynamic instability, maximum aortic diameter (MAD) >55 mm, significant periaortic hemorrhage and FID in acute phase of IMH are predictors of acute-phase mortality. In these cases, TEVAR or open surgery should be considered. In non-complicated IMH or PAU, without significant aortic enlargement, strict control of cardiovascular risk factors and frequent follow-up imaging appears to be a safe management strategy.