Unusual Aneurysm of a Cervical Aortic Arch: Surgical Repair Improves Fluid Dynamics.

The cervical aortic arch is a rare congenital vascular abnormality related to the anomalous development of the aortic arch. We present the case of a 6-year-old patient with a large aneurysmal cervical aortic arch who underwent surgical correction and arch reconstruction. Surgical repair was indicated based on the risk of progressive dilation and rupture, aiming to restore correct geometry and hemodynamics. We evaluated preoperative and postoperative hemodynamics using computational fluid dynamics simulations, and we also identified, within the repaired region, an area that remains affected by greater turbulent flow, requiring follow-up surveillance.

Titanium Biohybrid Middle Ear Prostheses: A Preliminary In Vitro Study.

Ossiculoplasty is a surgical operation performed to restore auditory transmission through the reconstruction of the ossicular chain using prosthetics. Tissue bioengineering has assumed a pivotal role in implementing alternatives to conventional ossicular middle ear replacement prostheses, to overcome extrusion while preserving acoustic properties. This in vitro study aims to explore, for the first time in current literature, the feasibility of a biohybrid middle ear prosthesis, composed of titanium surrounded by a bone extracellular matrix as bio-coating. We have hereby studied the adhesion and proliferation of human adipose-derived mesenchymal stem cells (hASC) on titanium scaffolds in vitro. Moreover, we identified the osteogenic differentiation of hASC using an immunofluorescence assay to analyze osteoblasts' gene expression profiles (Alp, Runx2, Col1a1, Osx, and Bglap), and we counted the presence of collagen as a marker of hASC's ability to secrete an extracellular matrix. We utilized scanning electron microscopy to evaluate the presence of an extracellular matrix on the scaffolds. Our preliminary data demonstrated the titanium's ability to support human adipose-derived mesenchymal stem cell colonization, proliferation, and osteoblastic differentiation, in order to obtain a biohybrid device. Our experience seems encouraging; thus, we advocate for further in vivo research to corroborate our results regarding bone transplantation.

3D bioprinted osteosarcoma model for experimental boron neutron capture therapy (BNCT) applications: Preliminary assessment.

Osteosarcoma is the most frequently primary malignant bone tumor characterized by infiltrative growth responsible for relapses and metastases. Treatment options are limited, and a new therapeutic option is required. Boron neutron capture therapy (BNCT) is an experimental alternative radiotherapy able to kill infiltrative tumor cells spearing surrounding healthy tissues. BNCT studies are performed on 2D in vitro models that are not able to reproduce pathological tumor tissue organization or on in vivo animal models that are expensive, time-consuming and must follow the 3R's principles. A 3D in vitro model is a solution to better recapitulate the complexity of solid tumors meanwhile limiting the animal's use. Objective of this study is to optimize the technical assessment for developing a 3D in vitro osteosarcoma model as a platform for BNCT studies: printing protocol, biomaterial selection, cell density, and crosslinking process. The best parameters that allow a fully colonized 3D bioprinted construct by rat osteosarcoma cell line UMR-106 are 6 × 106 cells/ml of hydrogel and 1% CaCl2 as a crosslinking agent. The proposed model could be an alternative or a parallel approach to 2D in vitro culture and in vivo animal models for BNCT experimental study.

Characterization of a Bioink Combining Extracellular Matrix-like Hydrogel with Osteosarcoma Cells: Preliminary Results.

Three-dimensional (3D) bioprinting allows the production of artificial 3D cellular microenvironments thanks to the controlled spatial deposition of bioinks. Proper bioink characterization is required to achieve the essential characteristics of printability and biocompatibility for 3D bioprinting. In this work, a protocol to standardize the experimental characterization of a new bioink is proposed. A functionalized hydrogel based on gelatin and chitosan was used. The protocol was divided into three steps: pre-printing, 3D bioprinting, and post-printing. For the pre-printing step, the hydrogel formulation and its repeatability were evaluated. For the 3D-bioprinting step, the hydrogel-printability performance was assessed through qualitative and quantitative tests. Finally, for the post-printing step, the hydrogel biocompatibility was investigated using UMR-106 cells. The hydrogel was suitable for printing grids with good resolution from 4 h after the cross-linker addition. To guarantee a constant printing pressure, it was necessary to set the extruder to 37 °C. Furthermore, the hydrogel was shown to be a valid biomaterial for the UMR-106 cells' growth. However, fragmentation of the constructs appeared after 14 days, probably due to the negative osteosarcoma-cell interference. The protocol that we describe here denotes a strong approach to bioink characterization to improve standardization for future biomaterial screening and development.

Role of Preoperative Ultrasound Shear-Wave Elastography and Radiofrequency-Based Arterial Wall Tracking in Assessing the Vulnerability of Carotid Plaques: Preliminary Results.

We aimed at evaluating the ability of point shear-wave elastography (pSWE) and of a radiofrequency (RF) echo-tracking-based method in preoperatively assessing the vulnerability of the carotid plaque in patients undergoing carotid endarterectomy (CEA) for significant asymptomatic stenosis. All patients who underwent CEA from 03/2021 to 03/2022 performed a preoperative pSWE and an RF echo-based wall evaluation of arterial stiffness using an Esaote MyLab ultrasound system (EsaoteTM, Genova, Italy) with dedicated software. The data derived from these evaluations (Young's modulus (YM), augmentation index (AIx), pulse-wave velocity (PWV)) were correlated with the outcome of the analysis of the plaque removed during the surgery. Data were analyzed on 63 patients (33 vulnerable and 30 stable plaques). In stable plaques, YM was significantly higher than in vulnerable plaques (49.6 + 8.1 kPa vs. 24.6 + 4.3 kPa, p = 0.009). AIx also tended to be slightly higher in stable plaques, even if it was not statistically significant (10.4 + 0.9% vs. 7.7 + 0.9%, p = 0.16). The PWV was similar (12.2 + 0.9 m/s for stable plaques vs. 10.6 + 0.5 m/s for vulnerable plaques, p = 0.16). For YM, values >34 kPa had a sensitivity of 50% and a specificity of 73.3% in predicting plaque nonvulnerability (area under the curve = 0.66). Preoperative measurement of YM by means of pSWE could be a noninvasive and easily applicable tool for assessing the preoperative risk of plaque vulnerability in asymptomatic patients who are candidates for CEA.

Modifications in Aortic Stiffness After Endovascular or Open Aortic Repair: A Systematic Review and Meta-Analysis.

OBJECTIVE: Increased aortic stiffness (AoS) has been recognised as a risk factor in the development of cardiovascular disease. The aim of this systematic review and meta-analysis was to assess the impact of aortic repair on AoS. DATA SOURCES: PubMed, Scopus, and Web of Science were searched systematically for relevant studies evaluating the consequences of endovascular and open aortic repair on AoS. REVIEW METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) statement was followed to perform the research process. Papers containing data on AoS before and after both thoracic (TEVAR) and abdominal (EVAR) endovascular repair, as well as open surgical repair (OSR), were included for detailed evaluation. A fixed effects model was used to perform analysis. The Newcastle-Ottawa Scale was calculated for each included study. RESULTS: The first article cluster comprised 367 papers. After removal of duplicates and the adoption of inclusion/exclusion criteria, 14 articles remained, 13 of which were selected for meta-analysis. Ten studies analysed EVAR and three analysed TEVAR. Five of the selected papers were case control studies, with OSR adopted in four of these as the EVAR comparator. Several graft types were used in the endovascular group. AoS increased after TEVAR and EVAR, in terms of pulse wave velocity (PWV), even though several spatial levels and measurement modalities were adopted. No differences were described after OSR, although no pooled data could be analysed. CONCLUSION: EVAR and TEVAR both demonstrated a significant increase in AoS measurement (PWV). Although the heterogeneity and the low number of available studies limit the strength of the results, this review highlights the potential deleterious endograft role in the cardiovascular system although further studies are needed to achieve robust evidence. Further studies are needed to improve the mutual interaction between aorta and endograft, minimising their impact on the native aortic wall properties.

Drag Forces after Thoracic Endovascular Aortic Repair. General Review of the Literature.

BACKGROUND: Despite the great evolution of endograft devices for thoracic endovascular aortic repair (TEVAR), threatening related complication such as graft migration and endoleaks still occur during follow up. The Drag Forces (DF), that is the displacement forces that play a role in graft migration and endoleaks caused by the blood flow against the thoracic graft, can be studied by means of Computational Fluid Dynamics (CFD). METHOD: A general review of papers found in current literature was performed. CFD studies available on the topic of thoracic aortic diseases and DF were analyzed. All anatomic, hemodynamics or graft related factors which could have an impact on DF were reported. RESULTS: Different factors deeply influence DF magnitude in the different site of the Ishimaru's zones classification: angulation, tortuosity and length of the landing zone, graft diameter, length and deployment position, blood pressure, pulse waveform, blood viscosity and patient heart rate have been related to the magnitude of DF. Moreover, also the three-dimensional orientation of DF is emerging as a fundamental issue from CFD studies. DF can be divided in sideways and upward components. The former, even of higher magnitude in zone 0, maintain always an orthogonal orientation and does not change in any type of aortic arch; the latter result strictly related to the anatomic complexity of the aortic arch with values up to four times higher in zone 3. CONCLUSION: Different DF magnitude and orientation could explain how TEVAR have higher rate of migration and endoleaks when we face with more complex aortic anatomies. All these aspects should be foreseen during the planning of TEVAR procedure. In this field, collaboration between physicians and engineers is crucial, as both parts have a primary role in understanding and describing hidden aspects involved in TEVAR procedures.

Prediction model of isolated iliac and abdominal aneurysms.

OBJECTIVES: We analyse the cardiovascular risk factors in patients undergoing screening for Isolated Iliac Aneurysm (IIA) and Abdominal Aortic Aneurysm (AAA) and propose a logistic regression model to indicate patients at risk of IIA and/or AAA. METHODS: A screening programme was carried out to identify the presence of aneurysm based on Duplex scan examination. Cardiovascular risk factors information was collected from each subject. A descriptive analysis for the incidence of IIA and AAA stratified by age and sex was carried out to evaluate factors incidence. A logistic regression model was developed to predict the probability of developing an aneurysm based on the observed risk factor levels. A threshold probability of aneurysm risk for a datum patient was also identified to effectively direct screening protocols to patients most at risk. RESULTS: A cohort of 10 842 patients was evaluated: 1.52% affected by IIA, 2.69% by AAA and 3.90% by at least one. Risk factors analysis showed that: IIA was correlated with cardiological status, diabetes, cardiovascular disease family history, and dyslipidaemia; AAA was correlated with cardiological status, body mass index, hypertension, and dyslipidaemia; diabetes and dyslipidaemia were the most relevant factors with at least one aneurysm. The prediction tool based on the logistic regression and the threshold probability predict the presence of IIA and AAA in 69.7% and 83.8% of cases, under k-fold cross-validation. CONCLUSIONS: The proposed regression model can represent a valid aid to predict IIA and AAA presence and to select patients to be screened.

Patient-specific computational fluid dynamics analysis of transcatheter aortic root replacement with chimney coronary grafts.

OBJECTIVES: Transcatheter aortic root repair (TARR) consists of the simultaneous endovascular replacement of the aortic valve, the root and the proximal ascending aorta. The aim of the study is to set-up a computational model of TARR to explore the impact of the endovascular procedure on the coronary circulation supported by chimney grafts. METHODS: Computed tomography of a patient with dilated ascending aorta was segmented to obtain a 3-dimensional representation of the proximal thoracic aorta, including aortic root and supra-aortic branches. Computed assisted design tools were used to modify the geometry to create the post-procedural TARR configuration featuring the main aortic endograft integrated with 2 chimney grafts for coronary circulation. Computational Fluid Dynamics simulations were run in both pre- and post-procedural configurations using a pulsatile inflow and lumped parameter models at the outflows to simulate peripheral aortic and coronary circulation. Differences in coronary flow and pressure along the cardiac cycle were evaluated. RESULTS: After the virtual implant of the TARR device with coronary grafts, the flow became more organized and less recirculation was seen in the ascending aorta. Coronary perfusion was guaranteed with negligible flow differences between pre- and post-procedural configurations. However, despite being well perfused by chimney grafts, the procedure induces an increase of the pressure drop between the coronary ostia and the ascending aorta of 8 mmHg. CONCLUSIONS: The proposed numerical simulations, in the specific case under investigation, suggest that the TARR technique maintains coronary perfusion through the chimney grafts. This study calls for experimental validation and further analyses of the impact of TARR on cardiac afterload, decrease of aortic compliance and local pressure drop induced by the coronary chimney grafts.

Anomalous aortic origin of coronary artery biomechanical modeling: Toward clinical application.

OBJECTIVES: Anomalous aortic origin of the coronary artery can be associated with sudden cardiac death and ischemic events. Anatomic static characteristics mainly dictated surgical indications, although adverse events are usually related to dynamic physical effort. We developed a computational model able to simulate anomalous coronary behavior, and we aimed to assess its clinical applicability and to investigate coronary characteristics at increasing loading stress conditions. METHODS: We selected 5 patients with anomalous aortic origin of the coronary artery and 5 control subjects. For each of them, we construct a 3-dimensional model resembling the aortic root and coronary arteries based on 25 parameters obtained from computed tomography. Structural finite element analysis simulations were run to simulate pressure increasing in the aortic root during exercise (+40 mm Hg, +100 mm Hg with respect baseline condition, assumed at 80 mm Hg) and investigate coronary lumen characteristics. RESULTS: The 25 parameters were obtainable in all subjects with a consistent interobserver agreement. In control subjects, the right coronary artery had a more significant lumen expansion at loading conditions compared with anomalous aortic origin of coronary artery (6%-19.2% vs 1.8%-8.1%, P = .008), which also showed an inability to expand within the intramural segment. CONCLUSIONS: The proposed anomalous aortic origin of coronary artery model is able to represent the pathogenic disease mechanism after being populated with patient-specific data. It can assess the impaired expansion of anomalous right coronary at loading conditions, a process that cannot be quantified in any clinical set-up. This first clinical application showed promising results on quantifying pathological behavior, potentially helping in patient-specific risk stratification.

3D Automatic Segmentation of Aortic Computed Tomography Angiography Combining Multi-View 2D Convolutional Neural Networks.

PURPOSE: The quantitative analysis of contrast-enhanced Computed Tomography Angiography (CTA) is essential to assess aortic anatomy, identify pathologies, and perform preoperative planning in vascular surgery. To overcome the limitations given by manual and semi-automatic segmentation tools, we apply a deep learning-based pipeline to automatically segment the CTA scans of the aortic lumen, from the ascending aorta to the iliac arteries, accounting for 3D spatial coherence. METHODS: A first convolutional neural network (CNN) is used to coarsely segment and locate the aorta in the whole sub-sampled CTA volume, then three single-view CNNs are used to effectively segment the aortic lumen from axial, sagittal, and coronal planes under higher resolution. Finally, the predictions of the three orthogonal networks are integrated to obtain a segmentation with spatial coherence. RESULTS: The coarse segmentation performed to identify the aortic lumen achieved a Dice coefficient (DSC) of 0.92 ± 0.01. Single-view axial, sagittal, and coronal CNNs provided a DSC of 0.92 ± 0.02, 0.92 ± 0.04, and 0.91 ± 0.02, respectively. Multi-view integration provided a DSC of 0.93 ± 0.02 and an average surface distance of 0.80 ± 0.26 mm on a test set of 10 CTA scans. The generation of the ground truth dataset took about 150 h and the overall training process took 18 h. In prediction phase, the adopted pipeline takes around 25 ± 1 s to get the final segmentation. CONCLUSION: The achieved results show that the proposed pipeline can effectively localize and segment the aortic lumen in subjects with aneurysm.

Geometrical Evaluation of Aortic Sac Remodeling During Two-Step Thoracoabdominal Aortic Aneurysm Endovascular Repair.

BACKGROUND: The present study evaluates aneurysmal sac remodeling and the loss of the intercostal arteries after the first step of staged treatment of thoracoabdominal aortic aneurysms (TAAAs). The purpose of this approach is to keep the aneurysmal sac temporarily perfused to induce progressive thrombosis of the aneurysm while simultaneously allowing the spinal cord to establish adequate perfusion thereby promoting the development of collateral circulation. METHODS: All patients with type II or type III TAAAs, having undergone 2-step endovascular treatment with at least a 2-branch endoprosthesis at our institution between April 2017 and May 2019, were retrospectively evaluated. Thirty-day mortality and spinal cord ischemia was assessed. The mean number of the intercostal and lumbar arteries, coverage length between the left subclavian artery and the stent graft proximal landing zone, total volume of the aneurysmal sac, lumen volume, and thrombosis volume were measured by preoperative and first-step postoperative computed tomography angiography. Patients were also grouped based on the chosen endoprosthesis (group A: double-branch aneurysmal sac reperfusion; group B: single-branch aneurysmal sac reperfusion). RESULTS: Eleven patients (mean age: 76.5 years; range: 61-86) were considered. No 30-day mortality was observed after the first-step procedure, and 1 patient died after second-step treatment. No permanent paraplegia was observed after either the first or second endovascular steps. The lumen volume significantly decreased (27%; P < 0.001) after first-step endovascular treatment although there was a significant increase in aneurysm thrombosis (34% to 54%). The mean number of the intercostal arteries decreased from 19.7 to 9.3 (P < 0.001) after first-step endovascular treatment. Volume variations and percentage of intercostal loss did not significantly differ between the 2 groups. CONCLUSIONS: Although aneurysm volume continued to increase after first-step treatment, two-step endovascular treatment is a feasible alternative to reduce the risk of severe ischemia in patients with extended TAAAs.

Endovascular Treatment of an Internal Iliac Artery Aneurysm in a Patient with Previous Aortic Surgery Using a Novel Covered Stent Graft.

BACKGROUND: We report endovascular treatment of a patient with an isolated Internal Iliac Artery (IIA) aneurysm who was treated by positioning a novel covered stent that could adapt to different proximal and distal diameters. CASE REPORT: A 68-year-old man who had already had several previous aortic surgeries underwent endovascular treatment for a 41 mm isolated right IIA aneurysm. Two Viabahn VBX (W. L. Gore & Associates, Flagstaff, AZ) covered stents (7 × 79 mm and 8Lx59 mm) were placed from a 6 mm gluteal artery to an 11 mm Dacron hypogastric artery via contralateral femoral surgical access. No complications occurred. One-month follow-up computed tomography angiography (CTA) scan showed the complete exclusion of the aneurysmal sac with spontaneous endoleak resolution and patency of the covered stents. Geometric analysis of the postoperative CTA highlighted VBX conformability to the native vessel. Maximum stented vessel diameter ranged between 9 and 13 mm, and circularity was maintained along the whole stent length, even in zones of higher centerline curvature. CONCLUSIONS: The Viabahn VBX covered stent could be used to treat aneurysms of the IIA.

Bioink Composition and Printing Parameters for 3D Modeling Neural Tissue.

Neurodegenerative diseases (NDs) are a broad class of pathologies characterized by the progressive loss of neurons in the central nervous system. The main problem in the study of NDs is the lack of an adequate realistic experimental model to study the pathogenic mechanisms. Induced pluripotent stem cells (iPSCs) partially overcome the problem, with their capability to differentiate into almost every cell types; even so, these cells alone are not sufficient to unveil the mechanisms underlying NDs. 3D bioprinting allows to control the distribution of cells such as neurons, leading to the creation of a realistic in vitro model. In this work, we analyzed two biomaterials: sodium alginate and gelatin, and three different cell types: a neuroblastoma cell line (SH-SY5Y), iPSCs, and neural stem cells. All cells were encapsulated inside the bioink, printed and cultivated for at least seven days; they all presented good viability. We also evaluated the maintenance of the printed shape, opening the possibility to obtain a reliable in vitro neural tissue combining 3D bioprinting and iPSCs technology, optimizing the study of the degenerative processes that are still widely unknown.

3D printing of aortic models as a teaching tool for improving understanding of aortic disease.

BACKGROUND: A geometrical understanding of the individual patient's disease morphology is crucial in aortic surgery. The aim of our study was to validate a questionnaire addressing understanding of aortic disease and use this questionnaire to investigate the value of 3D printing as a teaching tool for surgical trainees. METHODS: Anonymized CT-angiography images of six different patients were selected as didactic cases of aortic disease and made into 3D models of transparent rigid resin with the Vat-photopolymerization technique. The 3D aortic models, which could be disassembled and reassembled, were displayed to 37 surgical trainees, immediately after a seminar on aortic disease. A questionnaire was developed to compare the trainees' understanding before (T0) and after (T1) demonstration of the 3D printed models. RESULTS: A panel of 15 experts participated in evaluating face and content validity of the questionnaire. The questionnaire validity was established and therefore the information investigated by the questionnaire could be synthetized using the mean of the items to indicate the understanding. The participants (mean age 28 years, range 26-34, male 59%) showed a significant improvement in understanding from T0 (median=7.25; IQR=1.50) to T1 (median=8.00; IQR=1.50; P=0.002). CONCLUSIONS: Preliminary data suggest that the use of 3D-printed aortic models as a teaching tool was feasible and improved the understanding of aortic disease among surgical trainees.

Assessment of geometrical remodelling of the aortic arch after hybrid treatment.

OBJECTIVES: The aim of this study was to measure the morphological remodelling of the ascending aorta, aortic arch and thoracic aorta after aortic arch hybrid treatment including debranching and stent graft implantation. METHODS: Preoperative, 1-month and 1-year follow-up of computed tomography angiography scans of 22 patients were analysed to compute the lumen centreline from the aortic root to the coeliac trunk, and the following measurements were derived: the total centreline length, distance from the aortic root to the left subclavian artery, distance from the left subclavian artery to the distal landing zone. For both pre- and postoperative centrelines, the pointwise curvature was measured at the proximal and the distal landing zones. The mean curvature values of the whole aortic segment and the endografting region of the ascending and the descending aorta were measured. Surface outerline was computed as well, and curvature values at the endograft landing points were extracted. RESULTS: At the 1-month follow-up, centreline length were already significantly increased (382.66 ± 48.69 to 388.1 ± 50.75 mm; P = 0.01). Centreline pointwise curvature increased in the proximal (+29%, P = 0.011) and the distal zones (+63%, P = 0.004). Similarly, pointwise curvature of the outerline significantly increased in the proximal (+77%, P = 0.01) and the distal landing zones (+100%, P = 0.04). The centreline mean curvature increased in the ascending aorta (+7%, P = 0.02) and decreased in the endografting region (-3.3%, P = 0.004). No evidence of a relationship of such a remodelling with the type of endograft and the type of pathology was observed. This remodelling trend was confirmed by the analysis of 1-year computed tomography angiographies. CONCLUSIONS: Hybrid arch repair was associated with a significant elongation of the vessel and a significant increase in the curvature on the ascending aorta and the descending aorta and on the endograft proximal and the distal landing zones.

Twelve-year Follow-up Post-Thoracic Endovascular Repair in Type B Aortic Dissection Shown by Three-dimensional Printing.

BACKGROUND: Thoracic endovascular repair (TEVAR) is currently considered the therapy of choice for complicated type B acute aortic dissection (TBAAD). Although several papers have reported good outcomes at short- and medium-term follow-up, some questions still remain regarding the long-term durability and re-intervention rate during follow-up. METHODS: We describe a case of a patient originally treated with TEVAR for TBAAD complicated by impending aortic rupture. RESULTS: Endovascular repair successfully excluded the flow through the primary entry tear but during the 12-year follow-up period the patient experienced several complications and re-interventions. Various full-size three-dimensional (3D) models of the patient-specific vasculature were printed to better explain the different interventional interventions over the 12 years of follow-up and as a hands-on tool for medical education. CONCLUSIONS: The present case report, involving long-term follow-up, provides an example of the effectiveness and the safety of TEVAR for the treatment of complicated TBAAD shown at short and medium-term follow-up. However, the long-term complications that were observed in this patient during follow-up support the importance of lifelong CTA surveillance. Furthermore, this study confirms the capability of 3D printing technology as a powerful tool to support communication with patients and residents' education through the physical analysis of the real cases.

The Modified Arch Landing Areas Nomenclature identifies hostile zones for endograft deployment: a confirmatory biomechanical study in patients treated by thoracic endovascular aortic repair†.

OBJECTIVES: Our goal was to confirm whether the Modified Arch Landing Areas Nomenclature (MALAN) for thoracic endovascular aortic repair, in which each landing area is described by indicating both the proximal landing zone (PLZ) and the type of arch (e.g. 0/I), identifies unfavourable landing zones for endograft deployment in diseased aortas. METHODS: Preoperative computed tomography angiography scans of 10 patients scheduled for thoracic endovascular aortic repair for aneurysm or penetrating ulcer of the arch and with a potential hostile PLZ were reviewed. Five had proximal deployment planned in MALAN area 3/III and 5, in MALAN area 2/III. The angulation of each PLZ was calculated. Computational fluid dynamics modelling was used to compute magnitude and orientation of pulsatile displacement forces in each PLZ. Normalized values based on PLZ areas (i.e. equivalent surface traction) were calculated. Results were compared to those obtained in healthy controls stratified by the MALAN. RESULTS: Angulation was severe (>60°) in MALAN areas 3/III and 2/III, which was consistent with the findings obtained in healthy controls. Increased magnitude (P = 0.021) and unfavourable orientation (i.e. orthogonal to the longitudinal aortic axis) of equivalent surface traction (P = 0.011) was also found in these areas compared to the adjacent ones, following the same pattern seen in the controls. Adverse events related to proximal endograft performance were reported in 3/10 cases. CONCLUSIONS: This study confirms in diseased aortas initial proof-of-concept findings on the predictive value of the MALAN to identify landing areas with a geometric and haemodynamic environment hostile for thoracic endovascular aortic repair. These adverse biomechanical features may entail an increased risk of dismal endograft performance.