Surgery of the thoracic aorta

Serum fetuin-a and risk of thoracic aortic aneurysms: a two-sample mendelian randomization study

Background

Recent studies have revealed a significant decrease in serum fetuin-A levels in atherosclerotic aneurysms, indicating that fetuin-A may play a protective role in the progression of arterial calcification. However, the specific mechanism behind this phenomenon remains unclear. We aimed to examine the association between fetuin-A levels in thoracic aortic aneurysms (TAAs) and risk of TAAs and to evaluate whether this association was causal.

Methods

A total of 26 SNPs were selected as instrumental variables for fetuin-A in 9,055 participants of European ancestry from the CHARGE consortium, and their effects on thoracic aortic aneurysm and decreased descending thoracic aortic diameter were separately estimated in 353,049 and 39,688 individuals from FinnGen consortium. We used two-sample Mendelian randomization (MR) analysis to examine the causal association. At the same time, we employed various methods, including random-effects inverse variance weighting, weighted median, MR Egger regression, and MR PRESSO, to ensure the robustness of causal effects. We assessed heterogeneity using Cochran's Q value and examined horizontal pleiotropy through MR Egger regression and retention analysis.

Results

Fetuin-A level was associated with a significantly decreasing risk of thoracic aortic aneurysm (odds ratio (OR) 0.64, 95% CI 0.47 - 0.87, P = 0.0044). Genetically predicted fetuin-A was also correlated with the decreased descending thoracic aortic diameter (β = -0.086, standard error (SE) 0.036, P = 0.017).

Conclusions

Serum fetuin-A level was negatively associated with risk of TTAs and correlated with the decreased descending thoracic aortic diameter. Mendelian randomization provides support for the potential causal relationship between fetuin-A and thoracic aortic aneurysm.

Acute Aortic Syndromes from Diagnosis to Treatment-A Comprehensive Review

This work aims to provide a comprehensive description of the characteristics of a group of acute aortic diseases that are all potentially life-threatening and are collectively referred to as acute aortic syndromes (AASs). There have been recent developments in the care and diagnostic plan for AAS. A substantial clinical index of suspicion is required to identify AASs before irreversible fatal consequences arise because of their indefinite symptoms and physical indicators. A methodical approach to the diagnosis of AAS is addressed. Timely and suitable therapy should be started immediately after diagnosis. Improving clinical outcomes requires centralising patients with AAS in high-volume centres with high-volume surgeons. Consequently, the management of these patients benefits from the increased use of aortic centres, multidisciplinary teams and an "aorta code". Each acute aortic entity requires a different patient treatment strategy; these are outlined below. Finally, numerous preventive strategies for AAS are discussed. The keys to good results are early diagnosis, understanding the natural history of these disorders and, where necessary, prompt surgical intervention. It is important to keep in mind that chest pain does not necessarily correspond with coronary heart disease and to be alert to the possible existence of aortic diseases because once antiplatelet drugs are administered, a blocked coagulation system can complicate aortic surgery and affect prognosis. The management of AAS in "aortic centres" improves long-term outcomes and decreases mortality rates.

Traumatic Aortic Dissection as a Unique Clinical Entity: A Single-Center Retrospective Study

BACKGROUND

This study aimed to compare the clinical characteristics, treatment approaches, and outcomes of the Stanford Type B traumatic aortic dissection (TAD) with non-traumatic aortic dissection (NTAD), and assess better management for TAD.

METHODS

We retrospectively analyzed patients who underwent thoracic endovascular aortic repair for Stanford type B aortic dissection at The First Hospital of China Medical University between 2014 and 2022. The patients were divided into TAD and NTAD groups based on whether they had a history of acute trauma. This study ultimately included 65 patients with TAD and 288 with NTAD. We assessed and compared the baseline characteristics, laboratory indicators, imaging features, surgical procedures, and follow-up results between the groups.

RESULTS

The TAD group was younger compared to the NTAD group (50.00 [IQR40.00-59.00] vs. 55.00 [IQR 47.00-61.00] years, p = 0.020). A lower percentage of the TAD group had a history of hypertension (20% vs. 71.18%, p < 0.001). The length of aortic dissection was shorter in the TAD group compared to the NTAD group (30.00 [IQR 22.00-40.00] vs. 344.00 [IQR 237.25-400.00] mm, p < 0.001). All patients with TAD underwent TEVAR following the same strategy as NTAD. The mean preoperative duration was 7.00 (IQR 2.00-14.00) days in the TAD group and 11.00 (IQR 8.00-15.00) days in the NTAD group (p < 0.001). TAD showed fewer complications after TEVAR in mid-to-long-term follow-up.

CONCLUSIONS

TAD is distinct from NTAD. TAD typically presents with more localized lesions than NTAD, and the patients experience a shorter preoperative duration and a better mid-to-long-term outcome.

Midterm outcomes of open repair versus endovascular descending thoracic aortic aneurysm repair

Objective

The study objective was to evaluate the midterm outcome of thoracic endovascular aortic repair compared with open repair in patients with descending thoracic aortic aneurysm.

Methods

From August 1993 to February 2023, 499 patients with descending thoracic aortic aneurysms underwent open repair (n = 221) or thoracic endovascular aortic repair (n = 278). Of these, 120 matched pairs were identified using propensity score matching based on age, sex, chronic lung disease, stroke, coronary artery disease, diabetes, ejection fraction, dialysis, peripheral vascular disease, prior cardiac surgery, connective tissue disease, and chronic dissection. Primary outcomes were postoperative paralysis, operative mortality, reoperation, and midterm survival.

Results

After matching, the preoperative demographics and comorbidities were balanced in both groups. Intraoperatively, open repair had a lower temperature (18 °C vs 36 °C) and more patients required blood products (66% vs 8%), P < .001. Postoperatively, patients undergoing thoracic endovascular aortic repair had fewer strokes (2.5% vs 9.2%; P = .03), less dialysis (0% vs 3.3%; P = .04), and shorter length of stay (5 days vs 12 days, P < .001), but similar lower-extremity paralysis (2.5% vs 2.5%, P = 1.00) compared with open repair. Furthermore, thoracic endovascular aortic repair had higher 7-year incidence of first reoperation (16.1% vs 3.6%, P < .001) but similar operative mortality (0.8% vs 4.2%; P = .10) and 10-year survival outcome (56%; 95% CI, 43-72 vs 58%; 95% CI, 49-68; P = .55) compared with open aortic repair. The hazard ratio was 0.93 (P = .78) for thoracic endovascular aortic repair for midterm mortality and 6.87 (P < .001) for reoperation.

Conclusions

Open repair could be the first option for patients with descending thoracic aortic aneurysms who were surgical candidates.

Elective Thoracic Aortic Aneurysm Surgery: A Tertiary Center Experience

Background A thoracic aortic aneurysm (TAA) is a diseased expansion of the thoracic aorta. There is morbidity associated with a dilated aorta, as well as significant mortality. Open thoracic surgery is the fundamental management for proximal lesions, offering definitive treatment with excellent results. This study aimed to summarize preoperative data and operative outcomes of patients who underwent TAA repair at our institution. Methods Data were retrospectively collected from 234 patients that underwent elective open thoracic surgery at University Hospital Southampton for TAA disease, between 2015 and 2019. Demographics, clinical factors, surgical details, as well as outcome measures, were gathered. Results There were 166 males and 68 females, with an overall mean age of 66 years. The breakdown of operations comprised 105 aortic roots, 171 ascending aorta, 20 aortic arch, and 12 descending aorta cases. The mean follow-up was 370 days. 30-day mortality was 5.13%. Mortality was associated with female gender, aortic root surgery, and prosthetic valves. Mean aortic diameters at the time of surgery for the non-genetic aortopathy and genetic aortopathy groups were respectively 4.93cm and 4.63cm in the aortic root, 5.56cm and 4.88cm in the ascending aorta, 5.08cm and 3.87cm in the aortic arch, and 6.63cm and 5.50cm in the descending aorta. Conclusion Several factors are associated with complications and morbidity, which should be considered when discussing the risks of intervention with patients. There were no neuroprotective strategies that altered post-operative neurological function. Current practice in our unit fits in with current international guidance.

Relationship between phenotypic features in Loeys-Dietz syndrome and the presence of intracranial aneurysms

OBJECTIVE

Loeys-Dietz syndrome (LDS) is a rare autosomal dominant condition characterized by aneurysms of the aorta, aortic branches, and intracranial arteries; skeletal and cutaneous abnormalities; and craniofacial malformations. Previous authors have reported that higher craniofacial severity index (CFI) scores, which indicate more severe craniofacial abnormalities, correlate with the severity of aortic aneurysm pathology. However, the association between syndromic features and the formation of intracranial aneurysms in LDS patients has yet to be determined. In this study, the authors evaluate the incidence of phenotypic abnormalities, craniofacial features, and Chiari malformation type I (CM-I) in a large LDS cohort and explore possible risk factors for the development of intracranial aneurysms.

METHODS

This was a retrospective cohort study of all patients with LDS who had been seen at the Marfan Syndrome and Aortopathy Center at Washington University School of Medicine in St. Louis in 2010–2022. Medical records were reviewed to obtain demographic, clinical, and radiographic data. The prevalence of craniofacial, skeletal, and cutaneous pathologies was determined. Bivariate logistic regression was performed to identify possible risk factors for the formation of an intracranial aneurysm.

RESULTS

Eighty-one patients with complete medical records and intracranial vascular imaging were included in the analysis, and 18 patients (22.2%) had at least 1 intracranial aneurysm. Patients frequently demonstrated the thin or translucent skin, doughy skin texture, hypertelorism, uvular abnormalities, and joint hypermobility typical of LDS. CM-I was common, occurring in 7.4% of the patients. Importantly, the patients with intracranial aneurysms were more likely to have CM-I (22.2%) than those without intracranial aneurysms (3.2%). The mean CFI score in the cohort with available data was 1.81, with higher means in the patients with the TGFBR1 or TGFBR2 disease-causing variants (2.05 and 3.30, respectively) and lower in the patients with the SMAD3, TGFB2, or TGFB3 pathogenic variants (CFI < 1). No significant CFI difference was observed in patients with or without intracranial aneurysms (2.06 vs 1.74, p = 0.61).

CONCLUSIONS

CM-I, and not the CFI, is significantly associated with the presence of intracranial aneurysms in patients with LDS. Surveillance for intracranial aneurysms is essential in all patients with LDS and should not be limited to those with severe phenotypes. Long-term monitoring studies will be necessary to determine whether a correlation between craniofacial abnormalities and adverse outcomes from intracranial aneurysms (growth, intervention, or rupture) exists.

Is location a significant parameter in the layer dependent dissection properties of the aorta?

Proper characterisation of biological tissue is key to understanding the effect of the biomechanical environment in the physiology and pathology of the cardiovascular system. Aortic dissection in particular is a prevalent and sometimes fatal disease that still lacks a complete comprehension of its progression. Its development and outcome, however, depend on the location in the vessel. Dissection properties of arteries are frequently studied via delamination tests, such as the T-peel test and the mixed-mode peel test. So far, a study that performs both tests throughout different locations of the aorta, as well as dissecting several interfaces, is missing. This makes it difficult to extract conclusions in terms of vessel heterogeneity, as a standardised experimental procedure cannot be assured for different studies in literature. Therefore, both dissection tests have been here performed on healthy porcine aortas, dissecting three interfaces of the vessels, i.e., the intima-media, the media-adventitia and the media within itself, considering different locations of the aorta, the ascending thoracic aorta (ATA), the descending thoracic aorta and the infrarenal abdominal aorta (IAA). Significant differences were found for both, layers and location. In particular, dissection forces in the ATA were the highest and the separation of the intima-media interface required significantly the lowest force. Moreover, dissection in the longitudinal direction of the vessel generally required more force than in the circumferential one. These results emphasise the need to characterise aortic tissue considering the specific location and dissected layer of the vessel.

Endovascular repair of a ruptured, extremely tortuous, descending thoracic aorta aneurysm with aortic coarctation

We have presented a case of a ruptured descending aortic aneurysm that was accompanied by extreme tortuosity and a pseudocoarctation at the level of the ligamentum arteriosum. We performed successful endovascular repair, covering the left subclavian artery, using a transapical-to-femoral artery (through-and-through) guidewire technique to overcome the tortuosity, with the option to perform balloon angioplasty in the case of an increased gradient over the coarctation. In the present case report, we have underlined the role of close collaborations with aortic expertise centers.

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

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

Thoracic Aortic Aneurysm: A Clinical Review

Thoracic aortic aneurysms are common. Most thoracic aortic aneurysms are degenerative. However, some are associated with connective tissue disorders, bicuspid aortic valves, or familial/genetic predisposition. Most are asymptomatic, discovered incidentally on imaging. Aortic diameter is the best predictor of the natural history and risk of complications. Treating hypertension and smoking cessation can slow their growth. Surveillance imaging and referral for prophylactic aortic repair based on absolute aneurysm diameter is the primary means to decrease mortality from thoracic aortic aneurysm. We provide a practical evidence-based summary of the pathophysiology, risk factors, associated genetic syndromes, and clinical management of thoracic aortic aneurysms.

Review of Current Advances in the Mechanical Description and Quantification of Aortic Dissection Mechanisms

Aortic dissection is a life-threatening event associated with a very poor outcome. A number of complex phenomena are involved in the initiation and propagation of the disease. Advances in the comprehension of the mechanisms leading to dissection have been made these last decades, thanks to improvements in imaging and experimental techniques. However, the micro-mechanics involved in triggering such rupture events remains poorly described and understood. It constitutes the primary focus of the present review. Towards the goal of detailing the dissection phenomenon, different experimental and modeling methods were used to investigate aortic dissection, and to understand the underlying phenomena involved. In the last ten years, research has tended to focus on the influence of microstructure on initiation and propagation of the dissection, leading to a number of multiscale models being developed. This review brings together all these materials in an attempt to identify main advances and remaining questions.

High-Risk Chief Complaints I: Chest Pain-The Big Three (an Update)

Nontraumatic chest pain is a frequent concern of emergency department patients, with causes that range from benign to immediately life threatening. Identifying those patients who require immediate/urgent intervention remains challenging and is a high-risk area for emergency medicine physicians where incorrect or delayed diagnosis may lead to significant morbidity and mortality. This article focuses on the 3 most prevalent diagnoses associated with adverse outcomes in patients presenting with nontraumatic chest pain, acute coronary syndrome, thoracic aortic dissection, and pulmonary embolism. Important aspects of clinical evaluation, diagnostic testing, treatment, and disposition and other less common causes of lethal chest pain are also discussed.

Avalanches and power law behavior in aortic dissection propagation

Aortic dissection is a devastating cardiovascular disease known for its rapid propagation and high morbidity and mortality. The mechanisms underlying the propagation of aortic dissection are not well understood. Our study reports the discovery of avalanche-like failure of the aorta during dissection propagation that results from the local buildup of strain energy followed by a cascade failure of inhomogeneously distributed interlamellar collagen fibers. An innovative computational model was developed that successfully describes the failure mechanics of dissection propagation. Our study provides the first quantitative agreement between experiment and model prediction of the dissection propagation within the complex extracellular matrix (ECM). Our results may lead to the possibility of predicting such catastrophic events based on microscopic features of the ECM.

Detectability of the artery of Adamkiewicz on computed tomography angiography of the aorta by using ultra-high-resolution computed tomography

PURPOSE

To evaluate the detectability of AKA on aortic computed tomography angiography (CTA) using ultra-high-resolution computed tomography (UHRCT).

MATERIALS AND METHODS

Twenty-eight patients were enrolled. They underwent aortic CTA with UHRCT (UHRCTA) and had previously undergone aortic conventional CTA (CCTA). The injection protocol of UHRCTA was the same as that of CCTA. The bolus tracking technique was used. UHRCTA images were reconstructed with adaptive iterative dose reduction (strong) and with forward-projected model-based iterative reconstruction solution. The matrix size and slice thickness on UHRCT were 1024 and 0.25 mm, respectively, and those on conventional CT were 512 and 0.5 or 0.67 mm, respectively. The UHRCTA and CCTA images were visually compared by using four scales. A score of 4 or 3 indicated that the AKA was assessable. In this instance, the contrast-to-noise ratios of each UHRCTA were measured. The exposure dose and signal-to-noise ratios were also investigated.

RESULTS

The AKA visualization scores obtained with UHRCTA with forward-projected model-based iterative reconstruction solution were significantly higher than those with adaptive iterative dose reduction (p = 0.018) and CCTA (p = 0.0024).

CONCLUSION

UHRCT can contribute to the better visualization of the AKA on aortic CTA.

Endovascular Repair of Thoracic Aortic Disease: Early and Midterm Experience

Thoracic aorta disease remains a challenging problem, and despite improvements, open repair techniques are still associated with significant morbidity and mortality. This is a retrospective review of 53 consecutive patients with thoracic aortic pathology who were treated with endovascular repair between September 1998 and December 2004 at a tertiary-care hospital. Endovascular stent graft placement was performed on 23 elective and 30 emergent patients (34 male patients, mean age 66 years, 21 to 85 years). Completion angiography revealed no endoleak in 47 (89%) patients, a type I endoleak in 4 patients, and a type II endoleak in 2 patients. Operative 30-day mortality for elective aneurysms (n = 22), emergent aneurysms (n = 10), dissection (n = 3), penetrating aortic ulcers (n = 7), and trauma (n = 11) was 0%, 40%, 0%, 29%, and 9%, respectively. In total, 46 (87%) patients survived 30 days, and 36 (78.3%) of the survivors were discharged home free of complications. Two patients (4%) experienced paraplegia. Median follow-up was 22 months (1 to 72 months). Intermediate-term results revealed 41 (89%) patients free of endoleak, stent migration, or aneurysmal expansion. Two (4%) patients required reintervention with an additional stent graft. There were 2 (4%) patients with late aortic-related deaths and four (9%) patients with non—aorticrelated late deaths. Endovascular stent graft placement for thoracic aorta disease can be performed successfully and safely with good perioperative and intermediate-term outcomes. Stent graft complication and reintervention rates are low, whereas intermediate survival rates are good. Long-term efficacy still needs to be evaluated.

[Hybrid procedures for aortic arch disease]

Different surgical approaches for aortic arch disease were reviewed in the article. We have also compared various vascular prostheses for aortic replacement.

Outcomes of Thoracic Aortic Surgery in Patients With Coronary Artery Disease - Based on the Japan Adult Cardiovascular Surgery Database

BACKGROUND

Coronary artery disease (CAD) is associated with increased morbidity and mortality after open repair of thoracic aorta. Nevertheless, the efficacy of preoperative coronary angiography (CAG) and revascularization is controversial. The aim of this study was to clarify the effect of preoperative CAD on surgical outcome by reviewing the Japan Adult Cardiovascular Database. Methods and Results: This study involved 4,596 patients who underwent open surgery for true thoracic aortic aneurysm between 2004 and 2009. After excluding patients with concomitant cardiac operation, except coronary artery bypass grafting (CABG), the remaining 1,904 patients with coronary artery stenosis included 995 cases of simultaneous CABG. The prevalence of CAD was significantly higher in patients with diabetes, renal dysfunction, hyperlipidemia, cerebrovascular disorders, peripheral artery lesions, old myocardial infarction (MI), and coronary intervention. Patients with simultaneous CABG had severe CAD compared with those without, with no other major differences in patient background noted. Thirty-day postoperative and in-hospital mortalities were higher in CAD patients. Incidence of perioperative MI was higher in patients who underwent open aortic repair with simultaneous CABG, but simultaneous CABG did not affect operative mortality.

CONCLUSIONS

In patients with surgically treated true aortic aneurysm, CAD was frequently observed, suggesting that aggressive preoperative coronary evaluation is needed.

A combined experimental-numerical lamellar-scale approach of tensile rupture in arterial medial tissue using X-ray tomography

Aortic dissection represents a serious cardio-vascular disease and life-threatening event. Dissection is a sudden delamination event of the wall, possibly leading to rupture within a few hours. Current knowledge and practical criteria to understand and predict this phenomenon lack reliable models and experimental observations of rupture at the lamellar scale. In an attempt to quantify rupture-related parameters, the present study proposes an analytical model that reproduces a uniaxial test on medial arterial samples observed under X-ray tomography. This model is composed of several layers that represent the media of the aortic wall, each having proper elastic and damage properties. Finite element models were created to validate the analytical model using user-defined parameters. Once the model was validated, an inverse analysis was used to fit the model parameters to experimental curves of uniaxial tests from a published study. Because this analytical model did not consider delamination strength between layers, a finite element model that included this phenomenon was also developed to investigate the influence of the delamination on the stress-strain curve through a sensitivity analysis. It was shown that shear delamination strength between layers, i.e. mode II separation, is essential in the rupture process observed experimentally.

Revised Endografting for a Giant Descending Thoracic Aorta Aneurysm due to Synchronous Type III/Ib Endoleak, Causing Dysphagia

BACKGROUND

Although surgical resection and graft replacement therapy for thoracic aortic aneurysms has advanced greatly over the last 20 years, significant perioperative morbidity and mortality still occur, particularly in patients considered high risk due to significant coexisting medical illness or previous operations performed for the treatment of intrathoracic disease.

METHODS

The case described is that of a patient with a giant (13.8 cm) symptomatic descending thoracic aorta aneurysm (DTAA), previously treated endovascularly 15 years ago. The expanding aneurysm was due to undiagnosed synchronous type III/Ib endoleak resulting in chronic malnutrition and eventually dysphagia and dyspnea due to compressive symptoms of the esophagus. Besides the risk of rupture, dyspnea and dysphagia with progressive weight loss were significant indications necessitating repair. Regarding his major comorbidities, the patient was identified as high risk for open surgical repair, therefore an endovascular option was offered. Two valiant tube endografts were inserted and deployed successfully without complications.

RESULTS

Postoperatively, upper gastrointestinal endoscopy imaging that was performed to the patient revealed marked persistent stenosis of the esophagus despite aneurysm pressure relief. However, at the multidisciplinary team meeting, an esophageal stenting was ruled out due to the risk of stent fracture and esophageal perforation with its devastating complications. Therefore, a conservative management was deemed appropriate for the patient taking into consideration the risks of prolonged hospitalization and malnourishment coupled with an unpredictable clinical course regarding the remission of the symptoms. Despite the slight gradual clinical improvement in the immediate postoperative period, the patient passed away at the 40th postoperative day due to hospital acquired pneumonia.

CONCLUSIONS

Following endovascular repair of giant DTAA compressing the esophagus, significant symptomatic improvement should not be always expected due to the large residual thrombotic aneurysm sac. Although compression symptoms can be managed conservatively in patients deemed at high risk for esophageal perforation, postoperative course and management is of paramount importance and should be treated on an individual basis.

Managing Incidental Findings on Thoracic CT: Mediastinal and Cardiovascular Findings. A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee presents recommendations for managing incidentally detected mediastinal and cardiovascular findings found on CT. The Chest Subcommittee was composed of thoracic radiologists who developed the provided guidance. These recommendations represent a combination of current published evidence and expert opinion and were finalized by informal iterative consensus. The recommendations address the most commonly encountered mediastinal and cardiovascular incidental findings and are not intended to be a comprehensive review of all incidental findings associated with these compartments. Our goal is to improve the quality of care by providing guidance on how to manage incidentally detected thoracic findings.

Fever of unknown origin in aortic dissection

Aortic dissection is the most devastating sequela of thoracic aortic disorder. Patients with acute aortic dissection typically manifest as an acute onset of severe chest pain, but occasionally present with atypical symptoms including fever of unknown origin. A total of 50 patients from 41 articles based on a complete literature retrieval were included in this study. More patients had a fever prior to pain. The time to presentation was 40.7 ± 105.6 days, the time to diagnosis was 52.9 ± 110.1 days, and the time to surgery/intervention was 1.8 ± 5.6 days. The patients' temperature on admission was 38.2 ± 0.6 °C and the maximal temperature recorded was 38.8 ± 0.4 °C. Laboratory findings showed increased white blood cell counts, cardiac enzymes, and inflammatory biomarkers. More pronounced laboratory findings of the infectious type than the inflammatory type aortic dissection could be helpful in the differential diagnosis. Half of patients warrant aortic repair with or without valve replacement, less than half of patients were conservatively managed, and a few were interventionally treated or were being followed up. The mortality rate was 9.5 %. Physicians should always bear in mind aortic dissection when patients present with fever of unknown origin particularly in those without chest pain. Laboratory findings may offer inflammatory evidence for the diagnosis. An early diagnosis as well as subsequent treatment is indispensable for patients' outcomes.

Pregnancy and Marfan syndrome

Pregnancy in women with Marfan syndrome (MFS) presents challenges to the clinician and the patient due to the increased incidence of maternal complications and involvement of the fetus, and deserves special consideration. The leading cause of morbidity and mortality in MFS is aortic dissection. This article presents an extensive review of available clinical information and provides recommendations for the management of patients with MFS during pregnancy.

Endovascular Stent Grafting for Aortic Arch Aneurysm in Aortoiliac Occlusive Disease following Aortic Arch Debranching and Aortobifemoral Reconstruction

Treatment of thoracic aortic aneurysms constitutes high mortality and morbidity rates despite improvements in surgery, anesthesia, and technology. Endovascular stent grafting may be an alternative therapy with lower risks when compared with conventional techniques. However, sometimes the branches of the aortic arch may require transport to the proximal segments prior to successful thoracic aortic endovascular stent grafting. Atherosclerosis is accounted among the etiology of both aneurysms and occlusive diseases that can coexist in the same patient. In these situations stent grafting may even be more complicated. In this report, we present the treatment of a 92-year-old patient with aortic arch aneurysm and proximal descending aortic aneurysm. For successful thoracic endovascular stent grafting, the patient needed an alternative route other than the native femoral and iliac arteries for the deployment of the stent graft. In addition, debranching of left carotid and subclavian arteries from the aortic arch was also required for successful exclusion of the thoracic aneurysm.

Aortic shear stress in patients with bicuspid aortic valve with stenosis and insufficiency

OBJECTIVES

Bicuspid aortic valve, characterized by valve malformation and risk for aortopathy, displays profound alteration in systolic aortic outflow and wall shear stress distribution. The present study performed 4-dimensional flow magnetic resonance imaging in patients with bicuspid aortic valve with right-left cusp fusion, focusing on the impact of valve function on hemodynamic status within the ascending aorta.

METHODS

Four-dimensional flow magnetic resonance imaging was performed in 50 subjects with right-left bicuspid aortic valve and 15 age- and aortic size-matched controls with tricuspid aortic valve. Patients with bicuspid aortic valve were categorized into 3 groups according to their aortic valve function as follows: bicuspid aortic valve with no more than mild aortic valve dysfunction (bicuspid aortic valve control, n = 20), bicuspid aortic valve with severe aortic insufficiency (n = 15), and bicuspid aortic valve with severe aortic stenosis (n = 15).

RESULTS

All patients with right-left bicuspid aortic valve exhibited peak wall shear stress at the right-anterior position of the ascending aorta (bicuspid aortic valve vs trileaflet aortic valve at the right-anterior position: 0.91 ± 0.23 N/m² vs 0.43 ± 0.12 N/m², P < .001) with no distinct alteration between bicuspid aortic valve with severe aortic insufficiency and bicuspid aortic valve with severe aortic stenosis. The predominance of dilatation involving the tubular ascending aorta (82%, type 2 aortopathy) persisted, with or without valve dysfunction. Compared with bicuspid aortic valve control subjects, the bicuspid aortic valve with severe aortic insufficiency group displayed universally elevated wall shear stress (0.75 ± 0.12 N/m² vs 0.57 ± 0.09 N/m², P < .01) in the ascending aorta, which was associated with elevated cardiac stroke volume (P < .05). The bicuspid aortic valve with severe aortic stenosis group showed elevated flow eccentricity in the form of significantly increased standard deviation of circumferential wall shear stress, which correlated with markedly increased peak aortic valve velocity (P < .01).

CONCLUSIONS

The location of peak aortic wall shear stress and type of aortopathy remained homogeneous among patients with right-left bicuspid aortic valve irrespective of valve dysfunction. Severe aortic insufficiency or stenosis resulted in further elevated aortic wall shear stress and exaggerated flow eccentricity.

Serial CT Volume and Thrombus Length Measurements after Endovascular Repair of Stanford Type B Aortic Dissection

Purpose:

To evaluate the outcome of stent-graft placement in Stanford type B aortic dissection using contrast-enhanced spiral computed tomographic (CT) measurements of true and false lumen volumes and thrombus length.

Methods:

Among 18 consecutive patients (13 men; mean age 60 years, range 44–79) who underwent endovascular repair of Stanford type B dissection, 12 completed at least a 12-month follow-up, which included CT measurements of true and false lumen volumes and thrombus lengths prior to discharge and at 6 and 12 months postimplantation. Volumes were assessed in 3 different aortic segments (A1, A2, A3) extending from the proximal attachment site of the prosthesis to the aortic bifurcation. In addition, thrombus length was measured to evaluate the influence of clot formation on outcome of the false lumen volume.

Results:

Mean follow-up was 27 months (range 12–60). Within 12 months, mean true lumen volumes showed statistically significant increases in the A1 (p<0.001) and A2 (p=0.003) segments; false lumen volumes showed a significant decrease in the A1 segment (p=0.002) but an insignificant increase in the A2 segment. No substantial volume changes were observed in the A3 segment. Extension of clot formation in the false lumen varied among patients and over time. Length of stent-grafts, percentage of stented dissection length, or visceral arteries originating from the false lumen did not significantly influence thrombus development, nor did these parameters or thrombus formation distal to the prosthesis have a relationship to false lumen volumes.

Conclusions:

Volumetric analysis after endovascular repair of Stanford type B dissection shows optimal technical outcome in the stented segment, whereas the false lumen in the segment immediately adjacent to the stent-graft seems to be a vulnerable area. Extension of clot formation beyond the endograft seems to be no reliable predictor of outcome.

Techniques of Proximal Root Reconstruction and Outcomes Following Repair of Acute Type A Aortic Dissection

BACKGROUND

The goal of this study was to compare the early and late outcomes of different techniques of proximal root reconstruction during the repair of acute Type A aortic dissection, including aortic valve (AV) resuspension, aortic valve replacement (AVR), and a root replacement procedure.

METHODS

All patients who underwent acute Type A aortic dissection repair between January 2000 and October 2010 at four academic institutions were compiled from each institution's Society of Thoracic Surgeons Database. This included 189 patients who underwent a concomitant aortic valve (AV) procedure; 111, 21, and 57 patients underwent AV resuspension, AVR, and the Bentall procedure, respectively. The median age of patients undergoing a root replacement procedure was significantly younger than the other two groups. Early clinical outcomes and 10-year actuarial survival rates were compared. Trends in outcomes and surgical techniques throughout the duration of the study were also analyzed.

RESULTS

The operative mortality rates were 17%, 29%, and 18%, for AV resuspension, AVR, and root replacement, respectively. Operative mortality (p = 0.459) was comparable between groups. Hemorrhage related re-exploration did not differ significantly between groups (p = 0.182); however, root replacement procedures tended to have decreased rates of bleeding when compared to AVR (p = 0.067). The 10-year actuarial survival rates for the AV resuspension, Bentall, and AVR groups were 72%, 56%, and 36%, respectively (log-rank p = 0.035).

CONCLUSIONS

The 10-year actuarial survival was significantly lower in those receiving AVR compared to those receiving root replacement procedures or AV resuspension. Operative mortality was comparable between the three groups.

Bypass Techniques for Descending Thoracic Aortic Surgery

The conduct of partial left heart bypass or partial car diopulmonary bypass (CPB) during surgery involving the descending thoracic aorta or thoracoabdominal aorta is one of the most unappreciated and misunder stood extracorporeal circulation procedures in cardio vascular surgery. It is different from conventional CPB, and although some uninitiated practitioners consider it simpler, it is in fact more complicated than conven tional CPB and involves different concepts. It requires expertise and skill in regulating the flow, pressure, and oxygenation of blood going to both the proximal and distal parts of the body and management of the special bypass or shunt procedures used, specialized monitor ing, and knowledge about the protection and preserva tion of organs both proximal and distal to the aortic clamping. It demands exquisite communication and un derstanding of the unique problems faced by the sur geon, anesthesiologist, and perfusionist.

Complementary roles of open and hybrid approaches to thoracoabdominal aortic aneurysm repair

OBJECTIVE

Thoracoabdominal aortic aneurysm (TAAA) repair remains a significant challenge with considerable perioperative morbidity and mortality. A hybrid approach utilizing visceral debranching with endovascular aneurysm exclusion has been used to treat high-risk patients and therefore allow repair in more patients. Limited data exist regarding long-term outcomes with this procedure as well as comparison to conventional open repair. This study describes our institutional algorithmic approach to TAAA repair using both open and hybrid techniques.

METHODS

Hybrid and open TAAA repairs performed between July 2005 and August 2015 were identified from a prospectively maintained institutional aortic surgery database. Perioperative morbidity and mortality, freedom from reintervention, and long-term and aorta-specific survival were calculated and compared between the two groups.

RESULTS

During the study period, 165 consecutive TAAA repairs were performed, including 84 open repairs and 81 hybrid repairs. Patients in the hybrid repair group were significantly older, were more frequently female, and had a generally greater comorbid disease burden, including significantly more chronic kidney disease. Despite the older and sicker cohort, there was no difference in in-hospital mortality between the two groups (9.9% hybrid vs 7.1% open; P = .59). Major morbidity rates differed by procedure, with patients undergoing open repair having a significantly higher rate of postoperative stroke (9.5% open vs 0% hybrid; P = .017), whereas patients undergoing hybrid repair had a higher rate of new permanent dialysis (14.8% hybrid vs 3.6% open; P = .043). There was no difference between groups in the rate of postoperative permanent paraplegia/paresis (8.3% open vs 7.4% hybrid; P = .294). There was a significantly increased rate of reintervention in the hybrid repair group (12.3% hybrid vs 1.2% open, P = .004), with all hybrid reinterventions performed because of endoleak. One-year survival was similar between groups at 69% in hybrid repairs vs 77% in open repairs. Long-term survival was worse in the hybrid group (5-year survival, 32% hybrid vs 56% open), although late survival appeared to be influenced mainly by comorbid disease burden, given the similar long-term aorta-specific survival between groups.

CONCLUSIONS

Use of an algorithmic approach whereby higher risk patients with TAAA are treated by a hybrid approach and lower risk patients with conventional open repair yields satisfactory short- and long-term outcomes. The availability of multiple options for TAAA repair within a single center likely allows repair in more patients with consequent decrease in the risk of aorta-related death, at the expense of increased reinterventions for endoleak.

Stent Grafts for Thoracic Aortic Pathology: Single-Center Experience in Western Australia

The purpose of this article is to report a single-center experience in treating thoracic aortic pathology with stent grafts. This is a retrospective review of cases done within a period of 30 months.

Between January 2002 and May 2004, 12 patients were treated in our institution with thoracic stent grafts ( n = 12) for various clinical conditions. There were seven men and five women. Three patients required emergency treatment ( n = 3), two for aortic transection and one for iatrogenic injury during lung biopsy. Others were treated electively ( n = 9).

All patients were high risk for open surgery. There was one perioperative death, with a patient with multiple trauma succumbing to head injury 4 weeks after stent graft insertion. There was no incidence of paraplegia. Three patients underwent bypass surgery in the neck to achieve an adequate proximal seal zone prior to stent grafting. One patient with an aneurysm of the descending thoracic aorta required an extension limb below the original graft for an increase in sac size, possibly owing to endotension. Renal failure occurred in one patient and resolved without dialysis. One patient died 18 months after her procedure, possibly owing to aneurysm expansion.

Stent grafts are a viable alternative to open surgery for thoracic aortic pathology in high-risk individuals. Visceral and spinal cord ischemia is less prevalent with stent grafts compared with open surgery. The short-term results are promising. Long-term follow-up is awaited. Stent grafts might have greater impact in the thoracic aorta than the abdominal aorta for which they were initially developed.

Endovascular Repair For Thoracic Aortic Disease: Tertiary Single-center Experience In Northwestern Greece

The purpose of this article is to report the initial experience with endovascular repair of thoracic aortic disease in a single tertiary vascular unit in northwestern Greece.

Between 2003 and 2005, 16 patients were treated with endovascular techniques for various pathologies of the descending thoracic aorta. Twelve patients were treated electively and four emergently. Operative and follow-up data for a mean time of 18.4 months were retrospectively collected and analyzed.

Primary technical success was obtained in 14 (87.5%) cases. No early or late deaths occurred, and there was no major operation-related complication. No paraplegia was observed in our patients. Stent graft–related complications occurred in 18.75% (one type 2 and two type 3 endoleaks), but they all had a favorable outcome. No further problems have been reported in any of our patients.

Endovascular stent graft repair for diseases of the thoracic aorta seems to be a promising alternative to open surgery, especially for high-risk patients. Long-term results are needed to confirm the early benefit of this treatment option with regard to morbidity and mortality rates. The potential of this technique to be applicable even in relatively small, tertiary vascular centers might be of great benefit to patients.

Sex-Related Differences Between Patients With Symptomatic Acute Aortic Dissection

We designed a retrospective cohort study to assess sex-related differences in clinical manifestations, incidence, and outcomes of patients with symptomatic acute aortic dissection (AAD). We collected clinical data from 2010 to 2015 of 400 patients with AAD. Patients' clinical characteristics, treatment, and outcomes were analyzed as a function of sex. Among 400 patients with AAD, the ratio of men to women was 3.18:1; the incidence of atherosclerosis was higher in women (P = 0.02). Dysphoria (P = 0.01), focal neurological deficits (P = 0.04), and pulse deficits (P = 0.03) were more frequent in men. Imaging findings revealed that pleural effusion (P < 0.01), celiac trunk involvement (P < 0.01), and superior mesenteric artery involvement (P = 0.02) were more frequent in men. Dissection-related pneumonia (P = 0.02), pulmonary atelectasis (P = 0.01), aortic intramural hematoma (P < 0.01), ischemic electrocardiographic changes (P = 0.03), and in-hospital complications such as myocardial ischemia (P = 0.03), hypoxemia (P < 0.01), cardiac tamponade (P = 0.01) occurred more frequently in women. Women with type A dissection had higher in-hospital mortality than men (P < 0.01). The presentation of AAD varies with a patient's sex. Women with AAD had clinical features different from men as follows: higher age of onset, more frequent inpatient complications, and higher in-hospital mortality. These findings may lead to a better understanding of aortic dissection in women that will improve their outcomes.