Aortic Arch Research Articles

Direct visualization of postoperative aortobronchial fistula on computed tomography.

Postoperative aortobronchial fistula (ABF) is a rare complication that can occur in 0.3%-5.0% of patients over an extended period of time after thoracic aortic surgery. Direct visualization of the fistula via imaging is rare. To investigate the relationship between computed tomography (CT) findings and the clinical signs/symptoms of ABF after thoracic aortic surgery. Six patients (mean age 71 years, including 4 men and 2 women) with suspected ABF on CT (air around the graft) at our hospital were included in this retrospective study between January 2004 and September 2022. Chest CT findings included direct confirmation of ABF, peri-graft fluid, ring enhancement, dirty fat sign, atelectasis, pulmonary hemorrhage, and bronchodilation, and the clinical course were retrospectively reviewed. The proportion of each type of CT finding was calculated. ABF detection after surgery was found to have a mean and median of 14 and 13 years, respectively. Initial signs and symptoms were asymptomatic in 4 patients, bloody sputum was found in 1 patient, and fever was present in 1 patient. The complications of ABF included graft infection in 2 patients and graft infection with hemoptysis in 2 patients. Of the 6 patients, 3 survived, 2 died, and 1 was lost to follow-up. The locations of the ABFs were as follows: 1 in the ascending aorta; 1 in the aortic arch; 2 in the aortic arch leading to the descending aorta; and 2 in the descending aorta. ABFs were directly confirmed by CT in 4/6 (67%) patients. Peri-graft dirty fat (4/6, 67%) and peri-graft ring enhancement (3/6, 50%) were associated with graft infection, endoleaks and pseudoaneurysms were associated with hemoptysis (2/6, 33%). Asymptomatic ABF after thoracic aortic surgery can be confirmed on chest CT. CT is useful for the diagnosis of ABF and its complications.

Aortic versus axillary artery cannulation for hemiarch replacement: single-centre real-world experience

BackgroundAortic arch disease is a major cause of acute dissections. Surgical replacement is the current curative treatment for aortic arch disease. While traditional aortic cannulation ensures lower body perfusion, axillary cannulation offers optimum cerebral perfusion.AimTo evaluate the outcomes of aortic and axillary cannulation methods in hemiarch replacements, focusing on postoperative perfusion and survival.Materials and methodsA retrospective analysis was conducted on 91 patients who underwent hemiarch replacement surgery between February 2007 and October 2016. Patients were divided into two groups based on the cannulation method: aortic cannulation (54 patients) and axillary cannulation (37 patients). Data regarding preoperative, intraoperative, and postoperative parameters were analyzed, including demographics, surgical outcomes, and complications.ResultsDemographic analysis showed comparable characteristics between the two groups, with notable differences in aortic disease severity and classification. Patients in the axillary group had a larger ascending aorta diameter (57.7 ± 10.8 mm vs. 51.8 ± 5.7 mm, p = 0.002) and a higher prevalence of acute dissections (27.0% (n = 10) vs. 3.7% (n = 2), p = 0.001). Cerebral protection methods varied significantly between the two groups (p < 0.001). Antegrade cerebral perfusion was used in 37.8% (n = 14) of the axillary group compared to 3.7% (n = 2) of the central group. The central cannulation group had a higher proportion of patients with temperatures under 20 °C (98.1% (n = 53) vs. 21.6% (n = 8), p < 0.001), whereas the axillary group maintained higher temperatures (24 –28 °C) in 68.6% (n = 23) of cases. AV repair/replacement was more frequent in the aortic cannulation group (48.2% (n = 26) vs. 18.9% (n = 7), p = 0.013). No significant disparities were observed in operative mortality or intraoperative complications. Statistical analysis showed no significant differences between the two groups in the in-hospital outcomes, but renal complications were more prevalent in the axillary cannulation group with 21.6% (n = 8) experiencing acute kidney injury compared to 9.3% (n = 5) in the central group (p = 0.098). The overall survival rate was slightly higher in the aortic cannulation group at various follow-up periods, yet no statistically significant difference was found between the two groups.ConclusionWe found no significant differences in safety and efficacy between axillary cannulation and aortic cannulation in hemiarch replacement procedures.

Accurate prenatal diagnosis of coarctation of the aorta by 3-step echocardiographic diagnostic protocol

BackgroundCoarctation of the aorta (CoA) is the most common undiagnosed congenital heart defect during prenatal screening. High false positive and false negative rates seriously affect prenatal consultation and postnatal management. The objective of the study was to assess the utility of various measurements to predict prenatal CoA and to derive a diagnostic algorithm.MethodsOne hundred and fifty-four fetuses with suspected CoA who presented at Fuwai Hospital between December 2017 and August 2021 were enrolled and divided into confirmed CoA cases (n = 47) and false positive cases (n = 107), according to their postnatal outcomes. The transverse aortic arch, isthmus, and descending aorta were measured in the long-axis view of the aortic arch. The angle between the transverse aortic arch (TAO) and the descending aortic arch (DAO) was defined as the TAO-DAO angle and measured in the long axis or sagittal view. Based on the database in GE Voluson E10 and the formula (Z = \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{\ ext{x}-{\\mu }}{\\alpha }$$\\end{document}), the standard score (Z-score) of the dimensions of the aorta were calculated in relation to the gestational age. The main echocardiographic indices were combined to design a 3-step diagnostic protocol. The TAO-DAO angle was used as the first step in the diagnostic model. The diameter of the transverse arch and the Z-score of the isthmus were the second step. The third-step indices included a Z-score of the transverse arch, diameter of the isthmus, distance from the left subclavian artery (LSA) to left common carotid artery (LCCA), the ratio of isthmus diameter and LSA diameter and ratio of the distances (the distance between the LSA and LCCA to the distance between the right innominate artery and LCCA). The receiver operating characteristic (ROC) curve determined the predictive capability of each diagnostic parameter, and the kappa test determined the diagnostic accuracy of the proposed model.ResultsThe cases with confirmed CoA had thinner transverse arches (1.92 ± 0.32 mm vs. 3.06 ± 0.67 mm, P = 0.0001), lower Z-scores of the isthmus (-8.97 ± 1.45 vs. -5.65 ± 1.60, P = 0.0001), smaller TAO-DAO angles (105.54 ± 11.51° vs. 125.29 ± 8.97°, P = 0.0001) and larger distance between the LSA and LCCA (4.45 ± 1.75 mm vs. 2.74 ± 1.07 mm, P = 0.0001) than the false positive cases. The area under the curve (AUC) was 0.947 (95% CI 0.91–0.98) for the TAO-DAO angle ≤ 115.75°, 0.942 (95% CI 0.91–0.98) for the transverse arch diameter ≤ 2.31 mm, 0.937 (95% CI 0.90–0.98) for the Z-score of the isthmus ≤ -7.5, and 0.975 (95% CI 0.95–1.00) for the 3-step diagnostic protocol with 97.8% sensitivity and 97.2% specificity. The kappa test showed that the model’s diagnostic accuracy was consistent with postnatal outcomes (kappa value 0.936, P = 0.0001).ConclusionsThe 3-step diagnostic protocol included the three most useful measurements and the additional indices with appropriate cut-off values. The algorithm is useful for the detection of aortic coarctation in fetuses with a high degree of accuracy.Trial registrationRetrospectively registered.

Bovine Arch and Laterality of Cardioembolic Stroke

Aims and Objectives: We aimed to find the correlation between cardioembolic and non-cardioembolic stroke incidence with bovine arch anatomical variation. Materials and Methods: Retrospectively, we identified about 1,500 brain MRI/MRA and neck MRA studies, from which 605 patients were found to have had an acute stroke, with a mean age of 62. Images were reviewed to identify anatomical variations of the aortic arch, particularly bovine configuration, and characterization of anterior and posterior circulation stroke. Results: Some 60% of patients had had a left-sided stroke. About 17% of patients had had an anterior embolic ischemic stroke, and another 7% had had a posterior embolic stroke. Within the non-embolic stroke, 56% were in the anterior circulation, while 27% were posterior non-embolic ischemic strokes. Some 30% of the patients were found to have bovine arch; from patients with ischemic stroke and bovine arch, about 17% were in the anterior circulation and 5% in the posterior. Conclusion: The bovine aortic arch is a risk factor for young-onset anterior circulation stroke. Bilateral and left-sided infarcts were more common.

Association of computed tomography-derived pectoralis muscle area and density with disease severity and respiratory symptoms in patients with chronic obstructive pulmonary disease: A case-control study

Rationale and objectivesComputed tomography (CT) is commonly used and offers an additional viewpoint for evaluating extrapulmonary symptoms, disease severity, and muscle atrophy. This study assessed whether the pectoralis muscle area (PMA) and pectoralis muscle density (PMD) are lower in patients with chronic obstructive pulmonary disease (COPD) than in healthy controls and elucidated their relationships with these variables. Materials and methodsThe participants were enrolled in the hospital outpatient clinic between October 2023 and May 2024. Information was obtained from questionnaires, lung function, and CT imaging findings. On full-inspiratory CT, the PMA and PMD were measured at the aortic arch level using predetermined attenuation ranges of −29 and 150 Hounsfield units. We observed lower PMA and PMD and evaluated their associations with lung function, respiratory symptoms, and CT imaging findings in patients with COPD. ResultsOverall, 120 participants were enrolled at baseline (60 healthy controls and 60 patients with COPD). PMA and PMD were lower with progressive airflow limitation severity in those with COPD. The degree of emphysema and air trapping, as well as lung function, were correlated with PMA and PMD (P < 0.05), although not with the COPD Assessment Test or modified Medical Research Council scores (P > 0.05). ConclusionParticipants with COPD had smaller PMA and PMD. These measurements were correlated with the severity of airflow limitation, lung function, emphysema, and air trapping, suggesting that these features of the pectoralis muscle obtained from CT are helpful in assessments of patients with COPD.

CT Angiography for Aortic Arch Anomalies: Prevalence, Diagnostic Efficacy, and Illustrative Findings.

Aortic arch anomalies encompass a diverse spectrum of conditions. Elucidating the prevalence of these anomalies, their impact on patient wellbeing, and the most effective diagnostic tools are crucial steps in ensuring optimal patient care. This paper aims to explore the various presentations of aortic arch anomalies, emphasizing the remarkable utility of computed tomography (CT) angiography in their definitive diagnosis and characterization. We conducted a retrospective study on patients who were submitted to the CT angiography of the thoracic aorta or supra-aortic trunks, or the contrast-enhanced CT scans of the thorax and/or cervical region between January 2021 and February 2024 in our Hospital. Out of the total of 2350 patients, 18 were diagnosed with aortic arch anomalies, with an average age of approximately 55 years. The aortic arch anomalies identified in the study were as follows: left aortic arch with the aberrant origin of the right subclavian artery, right aortic arch (types I and II), double aortic arch, aortic coarctation, aortic pseudocoarctation, and ductus diverticulum. Although often asymptomatic, aortic arch anomalies require recognition and CT using advanced post-processing techniques is the optimal diagnostic method with the ability to also identify other associated cardiac or vascular malformations.

Geometric changes and clinical risk factors from aortic arch to proximal internal carotid artery between normal subjects and moderate right carotid plaques

The anatomical features spanning from the aortic arch to the proximal carotid artery and the associated cardiovascular risks might significantly influence the development of right carotid plaque. Our research aimed to compare these anatomical and risk factors between individuals with no carotid plaque and those with moderate right-side carotid plaque within a Korean cohort. We conducted a retrospective, cross-sectional analysis involving 413 participants, categorized into a normal group (n = 339) and a right moderate carotid plaque group (defined as > 50% stenosis based on NASCET criteria) (n = 74). We collected data on cardiovascular risk factors and conducted laboratory tests. A 3D model of the carotid artery was constructed using cranio-cervical computed tomography angiography (CTA) data through semi-automated software. Measurements taken on this 3D model included the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), and carotid artery bifurcation (CAB) in terms of maximal vascular diameter, sectional area, angles of carotid bifurcation and ICA, and carotid tortuosity. When compared with the normal group, individuals in the right moderate carotid plaque group exhibited smaller angles at the carotid bifurcation, larger CCA diameter and sectional area (p < 0.01), advanced age, and a higher incidence of hypertension, diabetes, and stroke history (p < 0.05), along with reduced glomerular filtration rate (GFR) (p < 0.001). Multivariate analysis revealed that the sectional area of the bifurcation, calcification of the aortic bulb, and GFR were independently associated with the presence of right moderate carotid plaque (p < 0.01). Statistical analyses disclosed significant differences in both clinical risk factors and geometric changes in the region extending from the aortic arch to the proximal carotid artery among subjects with right moderate carotid plaque when compared to those without.

Evaluation of end-organ protection in newborns and infants after surgery of aortic arch hypoplasia: A prospective randomized study.

Surgical repair of aortic arch hypoplasia in children requires a "dry" surgical field with reliable end-organ protection. Perfusion strategies commonly involve deep hypothermic circulatory arrest (DHCA) and variations of the continuous perfusion techniques, such as selective antegrade cerebral perfusion (SACP) and full-flow perfusion with double aortic cannulation (DAC). We aimed to evaluate the end-organ protection in the surgery of aortic arch hypoplasia in newborns and infants using DHCA and DAC. 66 newborns and infants with aortic arch hypoplasia and biventricular anatomy were enrolled in this prospective study. Patients were randomly assigned into two groups according to the perfusion strategy - DHCA (n = 33); and DAC (n = 33). Primary endpoint: acute kidney injury (AKI), graded according to the KDIGO score. Secondary endpoints: neurological sequelae (pre- and postoperative MRI), in-hospital mortality. The lowest temperature was 32 (28; 34)°С in the DAC group and 23 (20; 25)°С in the DHCA group. The patients with DAC had lower incidence of AKI (6 patients (18.2%) versus 19 patients (57.6%); p = .017). In the multivariate analysis, the inotropic index at 48h was identified as a risk factor, increasing the risk of AKI by 4%. The DHCA group was associated with a 3.8-fold increase in the risk of AKI. There was no difference in hospital mortality between the DAC and DHCA groups (1 patient (3%) versus 3 patients (9.1%); p = .61). Neurological sequelae by MRI scan were observed in 18 patients (54.5%) in the DHCA group compared to 5 patients (15.15%) in the DAC group (p = .026). The only risk factor identified in the multivariate analysis for neurological lesions on MRI scan was the DHCA group, which increased the risk by 8.8 times. Surgical reconstruction of the aortic arch hypoplasia using the method of full-body perfusion reduces the incidence of neurological lesions and renal complications requiring renal replacement therapy compared with the deep hypothermic circulatory arrest in neonates and infants.

Enhancing Neuroprotection in Cardiac and Aortic Surgeries: A Narrative Review

Background: Neurological injury poses a significant challenge in aortic surgery, encompassing spinal cord injury from thoraco-abdominal aorta intervention or stroke post-surgery on the arch and ascending aorta. Despite ample literature and proposals, a fully effective strategy for preventing or treating neurological injury remains elusive. This narrative review aims to analyze the most common neuroprotective strategies implemented for aortic arch surgery and aortic surgery. Results: Results from the reviewed studies showed that several strategies, including deep hypothermia cardiac induction (DHCA) and cerebral perfusion techniques (retrograde cerebral perfusion, RCP, and selective anterograde cerebral perfusion, SACP) aim to mitigate these risks. Monitoring methods such as electroencephalogram (EEG), somatosensory evoked potential (SEPs), and near-infrared spectroscopy (NIRS) offer valuable insights into cerebral function during surgery, aiding in the management of hypothermia and perfusion. Pharmacological agents and blood gas management (pH stat vs. alpha stat, hematocrit level, glycemic control) are crucial in preventing post-operative complications. Additionally meticulous management of atheromatous debris is essential to minimize embolic risks during surgery. Methods: For this narrative review, PubMed, Scopus, and Medline have been used to search articles about neuroprotection strategies in aortic and aortic arch surgeries. The search was narrowed to articles between 1975 and 2024. A total of 3418 articles were initially identified to be potentially relevant for this review. A total of 66 articles were included and were found to match the inclusion criteria. Conclusions: While an overabundance of neuroprotection strategies exists for cardiac surgery, particularly in procedures involving the aorta and the arch, their efficacy varies, with some well-documented and others still under scrutiny. Further research is imperative to advance our comprehension and refine prevention techniques for cardiac-surgery-related brain injury. This is crucial given its substantial contribution to both mortality and, notably, post-operative morbidity.

Patient-Tailored Therapy for Complex Aortic Arch Anatomy: An Evolving Research Field with Custom-Made Solutions.

The treatment of complex aortic pathologies requires specialized techniques and tailored approaches due to each patient's unique anatomical and clinical challenges. The European Association for Cardiothoracic Surgery (EACTS) and the Society of Thoracic Surgeons (STS) new guidelines identify the aorta as the body's 24th organ and reiterate that multidisciplinary aortic teams are recommended for shared decision-making to determine optimal treatment strategies. Patients treated for conditions such as aneurysms, dissections, intramural hematomas, or penetrating aortic ulcers may develop complex forms over time, necessitating careful follow-up and timely corrective actions. Endovascular solutions can be favorable for older patients with complex anatomies and multiple comorbidities. However, when endovascular treatment is not feasible, hybrid treatments or open surgery must be considered if the patient's condition allows it. The risk-benefit ratio of each procedure must be carefully evaluated; choosing the best intervention or deciding not to intervene becomes a critical and challenging decision. At our Cardiac Surgery Center in Verona, a multidisciplinary team with over 20 years of experience in treating complex aortic arch pathologies extensively discussed different cases of complex aortic pathologies treated with endovascular, hybrid, or surgical approaches, emphasizing the importance of considering both anatomical and patient-specific characteristics. The decisions and treatments were often challenging, and unanimity was not always achieved, reflecting the complexity of finding the best solutions.

Distal Repair After Total Aortic Arch Replacement With Frozen Elephant Trunk in Patients With Chronic Multilevel Thoracic Aortic Disease

Distal Repair After Total Aortic Arch Replacement With Frozen Elephant Trunk in Patients With Chronic Multilevel Thoracic Aortic Disease

Hemodynamics in the treatment of pseudoaneurysm caused by extreme constriction of aortic arch with coated stent.

To evaluate the changes in distal vascular morphology and hemodynamics in patients with extremely severe aortic coarctation (CoA) after covered palliative (CP) stent dilation with different surgical strategies. Perioperative computed tomography angiography and digital subtraction angiography were utilized to construct three aortic models with varying stenosis rates and one follow-up model in a patient with extremely severe CoA. The models included: an idealized non-stenosed model (A: 0%), a model post initial stent deployment (B: 28%), a model post balloon expansion (C: 39%), and a model 18 months after post-balloon expansion (D: 39%). Consistent boundary conditions were applied to all models, and hemodynamic simulation was conducted using the pure fluid method. The narrowest and distal diameter of the stent increased by 34.71% and 59.29%, respectively, from model B to C. Additionally, the distal diameter of the stent increased by -13.80% and +43.68% compared to the descending aorta diameter, respectively. Furthermore, the ellipticity of the maximum cross-section of the aneurysm region in model A to D continued to increase. The oscillatory shear index at the stenosis to the region of the aneurysm were found to be higher in Models A and B, and lower in Models C and D. At the moment of maximum flow velocity, the blood flow distribution in models A and B was more uniform in the widest section of the blood vessels at the distal end of the stenosis, whereas models C and D exhibited disturbed blood flow with more than 2 eddy currents. The time-averaged wall shear stress (TAWSS) decreased in the distal and basal aneurysms, while it significantly increased at the step position. The aneurysmal region exhibited an endothelial cell activation potential value lower than 0.4 Pa-1. In patients with extremely severe CoA, it is crucial to ensure that the expanded diameter at both ends of the CP stent does not exceed the native vascular diameter during deployment. Our simulation results demonstrate that overdilation leads to a decrease in the TAWSS above the injured vessel, creating an abnormal hemodynamic environment that may contribute to the development and enlargement of false aneurysms in the early postoperative period. ClinicalTrials.gov, (NCT02917980).

Fetal heart quantification technique improves the prenatal prediction of coarctation of the aorta: A retrospective analysis.

Coarctation of the aorta (CoA) ranks among the most prevalent congenital heart defects and poses a life-threatening risk if left undiagnosed. Herein, we utilized fetal heart quantification (HQ) technology to improve the prenatal prediction of CoA. A retrospective analysis was conducted on 64 fetal cases with suspected aortic arch constriction, identified through prenatal ultrasound findings between November 2020 and March 2022 at the Department of Ultrasound, Sir Run Run Shaw Hospital, Zhejiang University. According to the follow-up results, these cases were divided into two groups: 35 cases confirmed as CoA by postpartum surgery or induction, and 29 cases initially suspected of CoA prenatally but subsequently ruled out postnatally. Additionally, 88 cases of normal fetuses were randomly selected as the control group. Both conventional M-mode ultrasound techniques and Fetal HQ software were utilized for fetal analysis across all groups. Parameters related to the heart were measured, including fetal 4-CV length, width, Global Spherical Index (GSI), Mitral Annular Plane Systolic Excursion (MAPSE), areas and ratios of the left and right ventricles, as well as lengths and ratios of the left and right ventricles. Functional measurements of the left and right ventricles included ejection fraction (EF), fractional area change (FAC), global longitudinal strain (GLS), fractional shortening (FS), end-diastolic diameter (ED), and sphericity index (SI). Left ventricular (LV)-GLS, LV-FAC, LV-EF, and LV-EF Z-score could potentially differentiate between true CoA and false CoA or normal groups and serve as potential indicators for the clinical diagnosis of CoA. The receiver operating characteristic (ROC) curves indicated that LV-GLS and LV-EF Z-score have the greatest predictive power for CoA diagnosis. The segments 6-12 of FS in the confirmed CoA group were significantly lower than those in the false CoA and normal groups. Fetal HQ technology, by assessing changes in the size and shape of the heart, can provide relatively reliable parameter support for the prenatal diagnosis of fetal aortic coarctation.

A Scoping Review of Definitions of Success in Endovascular Aortic Arch Repair.

The present standard of care to treat aortic arch pathologies is open surgical repair with cardiopulmonary bypass and deep hypothermic arrest. With approaches for total endovascular and extra-anatomic cervical debranching hybrid arch repair becoming more diverse, understanding what is considered a successful operation is prerequisite for a rigorous comparison of techniques. This review describes the specific outcomes reported, the rates of success, and the definitions of technical and clinical success in total endovascular and extra-anatomic cervical debranching hybrid aortic arch repair. A comprehensive search of MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials was performed. Studies with patients undergoing total endovascular or hybrid extra-anatomic cervical debranching repair of the aortic arch were included. Any publications including only patients with Ishimaru zone 2 or distal repairs were excluded from this review. Studies with less than 5 patients were excluded. Data extraction was performed by one author. Data items included were study design, procedure type, procedural details, underlying pathology, type of cervical debranching, type of endograft repair, surgical outcomes, definition of cerebrovascular events, technical success, and the definition of technical success. Of 1754 studies screened for review, 85 studies with 5521 patients were included. By frequency, the included studies examined the following interventions: fenestrated devices, branched devices, parallel grafting. Most studies were retrospective single-institution studies. There were no randomized controlled trials. Short-term mortality and cerebrovascular events were nearly universally reported, present in 99% and 95% of studies reviewed, respectively. Only 27% of studies provided an explicit definition for cerebrovascular events. While 75% of studies reported a technical success rate, only 45% of those studies provided explicit criteria. Clinical success rates were infrequently reported, present in only 5.9% of studies reviewed. The definitions of technical success that were provided fell short of analogous defined reporting standards in nearly all studies, inflating technical success rates. Definitions of cerebrovascular events and technical success require stringent criteria to uniformly compare various methods of endovascular aortic arch repair. A societal consensus document for reporting standards of endovascular aortic arch repair would allow for higher-quality outcomes research. Total endovascular and extra-anatomic cervical debranching hybrid operations are being increasingly utilized for complex aortic arch repair. These techniques, however, can be associated with serious complications. Currently, there is no accepted metric to define technical or report clinical outcomes. Due to the paucity of high-quality data, use of these approaches may be limited in clinical practice. This study emphasizes the need for the development of standards for reporting outcomes in endovascular aortic arch repair. Future studies can then utilize these benchmarks, whcih will allow for improved efficacy and safety in these techniques.

Democratizing biomedical simulation through automated model discovery and a universal material subroutine

AbstractPersonalized computational simulations have emerged as a vital tool to understand the biomechanical factors of a disease, predict disease progression, and design personalized intervention. Material modeling is critical for realistic biomedical simulations, and poor model selection can have life-threatening consequences for the patient. However, selecting the best model requires a profound domain knowledge and is limited to a few highly specialized experts in the field. Here we explore the feasibility of eliminating user involvement and automate the process of material modeling in finite element analyses. We leverage recent developments in constitutive neural networks, machine learning, and artificial intelligence to discover the best constitutive model from thousands of possible combinations of a few functional building blocks. We integrate all discoverable models into the finite element workflow by creating a universal material subroutine that contains more than 60,000 models, made up of 16 individual terms. We prototype this workflow using biaxial extension tests from healthy human arteries as input and stress and stretch profiles across the human aortic arch as output. Our results suggest that constitutive neural networks can robustly discover various flavors of arterial models from data, feed these models directly into a finite element simulation, and predict stress and strain profiles that compare favorably to the classical Holzapfel model. Replacing dozens of individual material subroutines by a single universal material subroutine—populated directly via automated model discovery—will make finite element simulations more user-friendly, more robust, and less vulnerable to human error. Democratizing finite element simulation by automating model selection could induce a paradigm shift in physics-based modeling, broaden access to simulation technologies, and empower individuals with varying levels of expertise and diverse backgrounds to actively participate in scientific discovery and push the boundaries of biomedical simulation.

Relationship Between Quantitative Tracheal Geometry and Clinical Course in Various Types of Vascular Ring.

To investigate the relationship between quantitative tracheal geometry and clinical course among various types of vascular ring and to identify factors correlating with symptom presentation. Patients with vascular ring diagnosed between April 2010 and December 2022 were included. All the patients were classified as type 1 (complete double aortic arch); type 2 (incomplete double aortic arch); type 3 (circumflex aorta); type 4 (right aortic arch and aberrant left subclavian artery with a left retroesophageal diverticulum of Kommerell); or type 5 (mirror-imaged right aortic arch with retroesophageal aortic diverticulum). Their clinical characteristics and quantitative variables on computed tomography (CT) were compared. Of the 50 patients enrolled, those with type 1 tended to have a smaller luminal tracheal diameter at the level of the ring. The median symptom-free survival time was shortest in this group (16.0days [95% confidence interval (CI): 9.4-51.0]), followed by type 3 (138.0days [95% CI: 0.0-851.4]). Type 1 (hazard ratio [HR]: 9.0; 95% CI: 2.3-35.0; P = 0.001), type 3 (HR: 4.2; 95% CI: 1.4-13.2; P = 0.013), and the percentage of tracheal narrowing in the anteroposterior projection (HR: 0.87; 95% CI: 0.78-0.96; P = 0.008) were significantly associated with symptom presentation in the time-dependent course. The aortic arch encircling the entire circumference in type 1 and high-pressure vasculature in front of the vertebral body in types 1 and 3 may contribute to raising the risk of symptom presentation.

Systematic Review and Meta-Analysis With Reconstructed Time-To-Event Data of Frozen Elephant Trunk and Conventional Aortic Repair.

Frozen elephant trunk (FET) has gained popularity since its inception. Nevertheless, the optimal approach for managing aortic arch pathologies remains subject of debate. This meta-analysis compared outcomes between patients undergoing FET and those undergoing conventional aortic repair. Systematic searches were conducted up to February 2024. Pooled results of short and long-term outcomes were computed. A systematic review identified 21 non-randomized studies encompassing 3240 patients. Short-term mortality was lower in FET recipients than in those undergoing conventional repair (OR [95% CI] = 0.58 [0.44-0.78], P < .01). Postoperative paraplegia incidence was higher in the FET cohort (OR = 1.85 [1.02-3.34], P = .04), while subgroup analysis showed no difference between the two groups in patients with acute aortic dissection. Long-term all-cause mortality was lower among FET recipients. Subgroup analysis showed FET was associated with reduced all-cause mortality (HR = 0.55 [0.39-0.79], P < .01) and aortic re-intervention (HR = 0.62 [0.39-0.99], P = .05) in acute aortic dissection patients. This meta-analysis underscores the favorable association between the utilization of FET and improved short and long-term outcomes compared with conventional repair, while paraplegia incidence was higher in the FET group. FET appears to offer superior benefits, particularly evident in patients with acute aortic dissection.

Efficacy of cardiopulmonary bypass method with blood delivery via femoral artery cannulation for paediatric aortic arch repair

IntroductionThe efficacy of cardiopulmonary bypass (CPB) management with blood delivery via femoral artery cannulation for paediatric aortic arch repair has yet to be reported. This study aimed to verify the hypothesis that this CPB method would reduce lactate elevation compared to CPB management using circulatory arrest of the lower body under deep hypothermia.MethodsThis study included patients who underwent paediatric aortic arch repairs between March 2012 and March 2018 at the German Paediatric Heart Centre, Sankt Augustin. Patients who were repumped intraoperatively were excluded. Group A (lower body circulatory arrest), Group F (retrograde aortic perfusion via femoral artery cannulation), and Group D (antegrade descending aortic perfusion) included 41, 18, and 15 patients, respectively. The CPB records were retrospectively reviewed for the minimum body temperature during CPB (℃), lactate levels before CPB (mmol/L), CPB duration (min), aortic clamp time duration (min), total urine output (mL) and changes in lactate levels during CPB (mmol/L).ResultsThe minimum body temperatures during CPB were 16.79 ± 1.48℃, 23.73 ± 4.67℃, and 30.59 ± 2.35 ℃ in Groups A, F, and D, respectively. The increases in lactate levels during CPB in Group F (1.06 ± 0.94) were significantly lower than in Group A (1.66 ± 0.90, p = 0.033); however, no different from Group D (0.92 ± 1.13, p = 0.807).ConclusionThis CPB method is a promising alternative to the CPB method using antegrade descending aortic perfusion for paediatric aortic arch repair.Trial registrationUMIN000052933.

Vascular Ring Surgical Repair: Re-Implantation of the Left Subclavian Artery into the Left Carotid Artery in a Pediatric Patient.

Vascular rings are a rare congenital anomaly of the aortic arch, in which a ring-shaped structure forms, surrounding the trachea and/or esophagus, potentially causing compression. We describe the case of a 14-month-old female patient with failure to thrive secondary to dysphagia, and a vascular ring formed by a right aortic arch, an aberrant left subclavian artery, and a left ligamentum arteriosum. Surgical repair involved ligamentum arteriosum division, Kommerell's diverticulum obliteration, and left subclavian artery re-implantation into the left carotid artery. Endoscopy and EndoFLIPTM evaluated the intraoperative improvement in esophageal narrowing and impedance, respectively. The postoperative period was uneventful, and follow-up visits demonstrated dysphagia resolution and a patent re-implanted left subclavian artery.

Aortic Outcome after Implementation of a Treatment Strategy for Type B Aortic Dissection Involving the Aortic Arch

ObjectiveTo evaluate outcomes achieved after implementing a treatment strategy for non-A non-B (NANB) (B 1-2 D according to the latest consensus document of the Society of Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) acute aortic dissection (AAD). MethodsThis retrospective observational study adhered to the STROBE checklist. All cases of NANB AAD (B 1-2 D) treated at our Institution between January 2016 and December 2022 were reviewed. Morbidity, mortality, aortic-related reintervention, and remodelling were analysed. ResultsAmong 519 cases of acute aortic syndrome, n=22 (4.2%) patients presented with NANB AAD (B 1-2 D) (n=16,72.7% men, mean age 61.5 years+/14.7). Eleven cases were managed with best medical treatment (BMT) alone. Among them, one patient (9.1%) died suddenly two days after diagnosis for aortic rupture. Frozen elephant trunk procedure (FET) was required in the remaining 11 patients: 7(31.8%) needed emergent operation for risks of impending aortic rupture/retrograde AD extension and 4(26.7%) underwent delayed surgery within a month from initial presentation. Overall, in-hospital mortality was 9.1% with both FET and BMT. At a median follow-up of 40 months (range 2 days-200 months) no other deaths occurred. A statistically significant differences in the rate of FL thrombosis (100% vs 55.5%, p=.033) and a significant positive aortic remodelling in zone 3 (p<.001) and 4 (p=0.038) were reported in operated versus medically managed patients. ConclusionThe best treatment for NANB is not established. We advocate for medical stabilisation with an operative approach that favours open surgery in the acute post dissection period, promotes aortic remodelling and carries acceptable risk in centres where FET is performed routinely.