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The aim was to investigate whether the "bovine" aortic arch (i.e. arch variant with a common origin of the innominate and left carotid artery (CILCA)) is associated with a consistent geometric configuration of proximal landing zones for thoracic endovascular aortic repair (TEVAR).Anonymised thoracic computed tomography (CT) scans of healthy aortas were reviewed to retrieve 100 cases of CILCA. Suitable cases were stratified according to type 1 and 2 CILCA, and also based on type of arch (I, II, and III). Further processing allowed calculation of angulation and tortuosity of the proximal landing zones. Centre lumen line lengths of each proximal landing zone were measured in a view perpendicular to the centre line. All geometric features were compared with those measured in healthy patients with a standard arch configuration (n = 60). Two senior authors independently evaluated the CT scans, and intra- and interobserver repeatability were assessed.The 100 selected patients (63% male) were 71.4 ± 7.7 years old. Type 1 CILCA (62/100) was more prevalent than type 2 CILCA (38/100), and the two groups were comparable in age (p = .11). Zone 3 presented a severe angulation (i.e. 60°), which was greater than in Zone 2 (p .001), and a consistently greater tortuosity than Zone 2 (p = .003). This pattern did not differ between type 1 and type 2 CILCA. A greater tortuosity was also observed in Zone 0, which was related to increased elongation of the ascending aorta (i.e. Zone 0), than the standard configuration. The CILCA had an overall greater elongation, and Zone 2 also was specifically longer. When stratifying by type of arch, reversely from Type III to Type I, the CILCA presented a gradual flattening of its transverse tract, which entailed a consistent progressive elongation (p = .03) and kinking of the ascending aorta, with a significant increase of Zone 0 angulation to even a severe degree (p = .001). Also, from Type III to Type I, Zone 2 presented a progressively shorter length (p = .004), which was associated with increased tortuosity (p .05). Mean intra- and interobserver differences for angulation measurements were 1.4° ± 6.8° (p = .17) and 2.0° ± 10.1° (p = .19), respectively.CILCA presents a consistent and peculiar geometric pattern compared with standard arch configuration, which provides relevant information for TEVAR planning, and may have prognostic implications.

Objective As elastin fibres in the aorta deteriorate with age, the descending thoracic aorta (DTA) becomes longer and more tortuous. In patients with DTA aneurysms, this increased tortuosity may result in a hostile haemodynamic environment for thoracic endovascular aortic repair (TEVAR). The objective of this study was to analyse how increased tortuosity affects haemodynamic displacement forces (DFs) in different segments of the DTA in patients with DTA aneurysms (DTAAs). Methods Thirty patients with DTAAs were selected to form three equal groups based on the maximum tortuosity of their DTA: low 60°. Computational fluid dynamics simulations were performed to calculate DFs in all patients. Image based segmentations were carried out to create patient specific models of the aortic geometry. When physiological simulation results were obtained, the haemodynamic DFs on the aortic wall were calculated in four segments of the DTA (zones 4A – D). To enable comparison of DFs in different segments, the DF was normalised by the aortic wall surface area, the equivalent surface traction (EST). Results The mean age was 73 years, with 67% male. In zone 4C, where most tortuosity occurs, the EST in patients with high tortuosity was more than three times higher, than those with low tortuosity (low, 743 N/m2; moderate, 956 N/m2; high, 2294 N/m2; p = .004). These differences could be attributed to the higher sideways components of the DF vectors, which were more than two times greater in patients with high tortuosity than in patients with low or moderate tortuosity (low, 5.01 N; moderate, 5.50 N; high, 13.21 N; p = .009). Conclusion High tortuosity results in increased displacement forces in the distal segments of the DTA. These forces should be taken into account when planning for TEVAR, as potentially they increase the risk of stent graft related complications, such as migration and endoleak.

BACKGROUND Currently, only patients with ascending aorta diameter exceeding 55mm will undergo prophylactic surgery. However, diameter alone is insufficient for precise risk stratification. An International Registry of Acute Aortic Dissections study showed that nearly 60% of patients with type A aortic dissection had a diameter

The maximal aortic diameter has been used as a key indication for whether to repair abdominal aortic aneurysms (AAAs). Aortic tortuosity has been proposed as another factor to consider. In the present study, we compared the degree of aortic tortuosity in ruptured AAAs with that of unruptured AAAs using computed tomography.We performed a retrospective review of a prospectively maintained database of patients who had undergone AAA repair from December 2014 to December 2019. Patients with a ruptured aneurysm (rAAA) were matched with patients with a nonruptured AAA (nrAAA) with the same maximal aneurysm diameter and age. The degree of aortic tortuosity, defined as the maximum lateral deviation from the aortic centerline, was measured on preoperative coronal computed tomography scans.During a 5-year period, 572 AAA cases were identified. The aortic tortuosity of the 25 rAAA cases was compared with that of a matched control group of 31 nrAAAs, selected by the same mean maximum diameter of 8.4 cm and similar patient age. In the rAAA group, the mean age was 74.8 years (84% men). In the nrAAA group, the mean age was 76.3 years (88% men). The mean aortic tortuosity for the rAAA and nrAAA groups was 9.3 ± 7.9 mm and 18.0 ± 11.2 mm, respectively (P .01).Greater aortic tortuosity was seen in the nrAAA cases compared with the rAAA cases at the same matched aneurysm size. Thus, aortic tortuosity might confer a reduced rupture risk. Further studies with larger cohorts are needed to verify this observation.

Objective Complications after thoracic endovascular aortic repair (TEVAR) are common. Even after a successful TEVAR, a late endoleak (>30 days) can occur. The objective of this study is to summarize the current evidence and, if lacking, the need of evidence regarding the incidence and predictive factors for type 1b endoleak in patients with aortic aneurysm treated with TEVAR. Method A systematic review of the literature was performed on endoleak type 1b, in patients with aortic aneurysm, after TEVAR. The PubMed and EMBASE databases were systematically searched for articles regarding endoleak type 1b up to January 2019. The main subjects discussed are the incidence, risk factors, treatment and prognosis. Results Seven hundred and twenty-two articles were screened and sixteen articles were included in this review. The reported incidence of endoleak is between 1.0 – 15.0%, with a mean follow-up duration of at least 1 year. Type 1b endoleak is associated with an increased aortic tortuosity index (> 0.15 cm-1). No significant difference is found in relation to age and gender. Treatment is required in most cases (22/27) and is usually performed with distal extension of the stent graft (21/27). There is no data regarding stent graft oversizing, length of distal landing zone and differences between devices or the prognosis for patients with type 1b endoleak. Conclusion Limited literature is available on the occurrence of type 1b endoleak following TEVAR. A tortuous aorta can be associated as a predictive factor for the occurrence of type 1b endoleak. Data clearly delineating the anatomical variables predicting type 1b endoleak should be examined and listed. Likewise, the impact of more recent, conformable devices, to prevent complications like type 1b endoleaks from occurring, should be elucidated.

INTRODUCTION: Arterial tortuosity has emerged as a predictor of adverse outcomes in congenital aortopathies using 3D reconstructed images. We validated a new method to estimate aortic arch tortuosity on 2D CT. We hypothesize that arch tortuosity may identify bicuspid aortic valve (BAV) patients at high risk to develop thoracic aortic aneurysms or aortic dissections (TAD). METHODS: BAV subjects with chest CT scans were retrospectively identified in our clinical records and matched to tricuspid aortic valve (TAV) controls by age, gender, and presentation with TAD. Subjects with prior ascending aortic intervention were excluded. Measurements included aortic arch tortuosity, length, angle, width and height. Total aortic tortuosity was estimated in subjects with available abdominal images. RESULTS: 120 BAV and 234 TAV subjects were included. Our 2D measurements were highly correlated with 3D midline arch measurements and had high inter- and intra-observer reliability. Compared to TAV, BAV subjects had increased arch tortuosity (median 1.76 [Q1-Q3: 1.62-1.95] vs. 1.63 [1.53-1.78], P < 0.01), length (149 [136-160] vs. 135 [122-152] mm, P < 0.01),height (46 [41-53]vs. 39[34-7]mm, P < 0.01),and vertex acuity (70[61-77]vs.75 [68-81] degree, P < 0.01). In a multivariable analysis, arch tortuosity remained independently associated with BAV after adjusting for aortic diameter and other clinical characteristics. CONCLUSIONS: We found that aortic arch tortuosity is significantly increased in BAV and may identify BAV patients who are at increased risk for TAD. Further studies to evaluate the association between tortuosity and clinical outcomes are in progress.

Background Although the incidence of aortic dissection is higher in patients with bicuspid aortic valve (BAV) compared to tricuspid aortic valve (TAV), risk stratification remains unclear. Guidelines focus on ascending aorta diameters, regardless of the location, and do not take into account the morphology of the aorta. Aortic tortuosity (AT) is emerging as a novel biomarker associated with more severe aortopathy in patients with Marfan syndrome. AT has not been accuretely assessed in BAV. Our aim is to describe the relationship between AT and ascending aortic phenotype in patients with BAV. Methods 83 patients (43±16 years, 19 women) diagnosed with BAV and without significant aortic valve disease nor prior aortic intervention were included. CT scans were retrospectively analysed with measurements of aortic diameters and aortic tortuosity. For 61 patients with abdominal images available, descending and total aortic length and tortuosity were measured. Results In our cohort, 62 (75%) patients presented a typical BAV. Pathological aorta (Root and/or tubular Z-score >2) was found in 80 patients (96%) and 67 (81%) presented a tubular dilatation. The aortic phenotype, the maximal aortic diameters and aortic tortuosity index were similar in typical and atypical BAV. Total aortic tortuosity index was correlated to Z-score tubular diameter (r=0.31; p=0,014) but not with Z-score Valsalva diameter (p=0,55). In patients with tubular dilatation (Z score >2), total aortic tortuosity index was higher than in patient without tubular dilatation (2.01 vs 1.85; p=0,015). Conclusion Total aortic tortuosity is associated with tubular dilatation but not with root dilatation in BAV patients suggesting that tubular phenotype may be at higher risk of complication in BAV. Further studies evaluating the association between aortic tortuosity and clinical outcomes in BAV are needed. Funding Acknowledgement Type of funding sources: None.

Objective Concern regarding the use of anatomic fixation endografts was raised as previous data suggested increased risk of late device uncoupling and type IIIa endoleak in this setting. Some risk factors have been identified as predictors of graft failure. We aim to determine if increase in aortic tortuosity index over the time is associated with increased risk of type IIIa endoleak. Methods We conducted a single center retrospective cohort study of patients treated with endovascular repair of infrarenal abdominal aortic aneurysms with the Endologix platform. Patients with at least two postoperative CT scans were included in the analysis. Aortic tortuosity index was determined in the first and last available CT scan to determine any change. Multivariate analysis was performed in order to detect risk predictors of type IIIa endoleak occurrence. Results A total of 173 patients were included in the analysis. 21 patients (12.1%) presented type IIIa endoleak. Cumulative freedom from type IIIa endoleak determined by Kaplan-Meier method was 99.4%, 92.5%, 86.1% and 83.3% at 1, 3, 5 and 8 years respectively. Time dependent optimal cutoff values of 0.03 for aortic tortuosity index increase and 15 mm for decrease in modules overlapping over time were obtained with Contal and O’Quigley method to predict type IIIa endoleak. After dichotomizing data around these critical values, a Cox proportional hazards model was obtained to predict type IIIa endoleak occurrence. Maximum preoperative AAA diameter (OR 1.09), smoking (OR 26.67), initial device components overlap (OR 0.91), aortic tortuosity index increase >0.03 (OR 4.56) and decrease in device components overlap > 15 mm (OR 6.13) were associated with type IIIa endoleak occurrence. Conclusions Aortic tortuosity index increase, device components overlap decrease, maximum preoperative aortic diameter, tobacco use and initial device components overlap were predictive of type IIIa endoleak occurrence. Close follow up with CT scan with aortic tortuosity index and device components overlap measure is warranted in these patients and prompt repair seems justified when any of these risk factors is present.

Introduction The risk ok type A aortic dissection (AAD) depends on the degree of aortic wall's alteration, which can result in dilatation or tortuosity. The estimate of this risk relies solely on the evaluation of the diameter of the ascending aorta. Purpose The purpose of this study is to evaluate the presence and importance of aortic tortuosity in patients with type A aortic dissection. Method Postoperative CT scans of patients with type A aortic dissection were compared with CT scans from controls matched for gender and age. After 3D reconstruction, total length (actual distance along aortic center line = Ltot) and geometric length (length of a straight line between start and end of the aortic segment = Lgeo) were measured to calculate the tortuosity index (TI = Ltot / Lgeo). Results Ltot, Lgeo and TI from different aortic segments of the AAD group were higher than in the control group. Ltot and TI of the whole aorta (from aortic valve to bifurcation) were greater in patients with type A aortic dissection (527.7±46.1 mm vs. 475.8±39.7, p1.3 identifies AAD patients with an accuracy of 74.8% (AUC = 0.792, p Conclusions Type A aortic dissection is associated with longer aorta and increased aortic tortuosity. This index may help recognize patients at risk for type A aortic dissection. Calculation of tortuosity indexes Funding Acknowledgement Type of funding source: None

Objectives Thoracic endovascular aortic repair technology focuses on accurately deploying the stent graft in the proximal landing zone in the proximal to distal direction. The aim of this in vitro study was to evaluate the accuracy of stent graft deployment in the distal landing zone. Methods It was hypothesised that a reverse implantation mechanism (in a distal to proximal deployment direction, when the operator starts to open the endoprosthesis from distal to proximal), might enhance landing accuracy in the distal LZ. The aim was to investigate this hypothesis by implanting stent grafts into the 3D printed aortas with the currently available deployment mechanism. Based on two human patients' computed tomography angiography scans, two aortas were 3D printed at 1:1 scale: “straight” and “crooked” aortas with distal aortic tortuosity of 1.006 and 1.078, respectively. They were used in order to test three endoprostheses (E-vita THORACIC 3G, Relay Plus, Valiant Captivia) 10 times by implanting them in three ways: proximal landing in the aneurysm, proximal landing in another stent graft, reverse implantation (via simulated antegrade access). The aim was to land just above the target vessel's upper edge. The distance to the target vessel and wedge apposition were assessed under a direct view using caliper. Results The distance to the target vessel was 3 mm (IQR 0; 8) if the stent graft landed proximally in aneurysm, 2 mm (IQR 0; 5) if it landed proximally in another stent graft, and 0 mm (IQR 0; 0) when reverse implantation was applied. The distance to the target vessel measuring 5 mm or occurred in 45%, 30%, and 0%, respectively. Overall the median wedge apposition after stent graft implantation was 0 mm (IQR 0; 0) in the “straight” versus 18 mm (IQR 15; 20) in the “crooked” aorta (p Conclusions Reverse stent graft deployment is associated with more accurate landing in the distal landing zone. Distal aortic tortuosity constitutes an important impediment to covering the distal LZ's entire circumference with a stent graft.

Purpose of review Retrograde type A aortic dissection (RTAD) is a fatal complication after endovascular therapy of type B aortic dissection and descending thoracic aneurysm disease. This review aims to elaborate this lethal complication, the potential risks of its incidence, and feasible approaches to lower the occurrence rate. Recent findings Many articles have shown lower incidence of RTAD in patients with thoracic aneurysm than those with aortic dissection. Also, acute aortic dissection seems to be more vulnerable when compared with chronic aortic dissection. Recent studies that focused on the risk of RTAD revealed that the mismatch of stent, the weakness of the aortic wall and intraoperative aortic injury played important roles in the development of RTAD. The mismatch of stent includes implanting the stent with the top bare spring, the location of landing zone, the oversizing of the stent on the proximal landing zone, and etc. Some centers presented some measures to lower the risks, such as increasing the oversizing of the stent, avoiding the aortic tortuosity, and locating in the healthy landing zone. Summary Ongoing research with improved technology and techniques continues to unravel new understanding and preventive measures of RTAD after endovascular treatment of aortic dissection and descending thoracic aneurysm disease. Cardiologists and vascular surgeons should be aware of current evidence and implement guidelines in relation to endovascular therapy of aortic diseases.

Purpose: To investigate the changes in the infrarenal aortic length and tortuosity in elderly patients. Materials and Methods : : We retrospectively reviewed the medical records and computed tomography (CT) scans of 857 patients who underwent surgery for colorectal cancer between August 2009 and July 2012. Among these patients, 48 patients who were aged ≥60 years, underwent follow-up CT at least 5 years after surgery, did not have aortic disease, and did not receive radiation therapy were enrolled. The aortic tortuosity index (ATI) was defined by dividing the distance along the central lumen line from the lowest renal artery to the aortic bifurcation (L1) by the straight-line distance from the lowest renal artery to the aortic bifurcation (L2). Aortic diameters were measured at the lowest renal artery level (D1) and 20 mm below (D2). A paired t-test and Wilcoxon signed-rank test were used to compare lengths and diameters between the initial and final CT scan. Spearman’s correlation analysis was performed to determine the correlations between time and the changes in L1 and ATI. Results : : The average follow-up period was 68 months. The mean changes in L1 and L2 were 0.69 mm and –0.59 mm, respectively, while the mean changes in D1 and D2 were 0.77 mm and 0.58 mm, respectively. The mean increase in ATI was 0.015. All findings were statistically significant. On Spearman’s correlation analysis, ΔL1 and ΔATI showed no correlation with follow-up duration. Conclusion : : The infrarenal aortic length and tortuosity of elderly patients increases at a slow rate over time.

Impact of arterial stiffness on aortic morphology has not been well evaluated. We sought to investigate the association of brachial-ankle pulse wave velocity (baPWV) with aortic calcification and tortuosity. A total of 181 patients (65.4 ± 10.4 years, males 59.7%) who underwent computed tomographic angiography and baPWV measurement within 1 month of study entry were retrospectively reviewed. Aortic calcification was quantified by the calcium scoring software system. Aortic tortuosity was defined as the length of the midline in the aorta divided by the length of linear line from the aortic root to the distal end of the thoraco-abdominal aorta. In simple correlation analyses, baPWV was correlated with aortic calcification (r = 0.36, P

Aortic tortuosity has been recognized as a significant predictor of aortic events and adverse consequences of endovascular procedure in many aortopathies. However, the traditional 3D tortuosity evaluation methods, based on the centerline length divided by the straight-line distance (L/D), have weakness in describing local details and spatial signatures of the aorta, resulting in the identical L/D measured on different aortas. In this paper, we firstly introduce the differential geometric scales in mathematics, 3D curvature and torsion, to characterize the tortuosity of the aorta from the local “bending” and “twisting”, and then arbitrarily choose seven clinical cases with diverse morphologies to test. The results demonstrate that, our technique clearly identifies the heterogeneous characteristics of the aortas, and quickly locks the positions on the aorta corresponding to the maxima of 3D curvature and torsion, whereas the traditional method cannot distinguish the tortuosity discrepancy well. Furthermore, a computational fluid dynamics simulation is performed to verify the utility of the novel parameters and to explore the correlations with hemodynamics. It is found that the areas with greater 3D curvature or torsion is highly consistent with the location where the higher-intensity vortices, resistive impedance, wall shear stress and the faster blood velocity occur, and the correlation with 3D curvature is higher than torsion by a series of linear regressions. Our study extends mathematical knowledge to the medicine field for evaluating aortic tortuosity, shedding new light on prospective anatomical research.

LTBP-4L and LTBP-4S are two isoforms of the extracellular matrix protein latent-transforming growth factor beta-binding protein 4 (LTBP-4). The mutational inactivation of both isoforms causes autosomal recessive cutis laxa type 1C (ARCL1C) in humans and an ARCL1C-like phenotype in Ltbp4−/− mice, both characterized by high postnatal mortality and severely affected elastogenesis. However, genetic data in mice suggest isoform-specific functions for Ltbp-4 because Ltbp4S−/− mice, solely expressing Ltbp-4L, survive to adulthood. This clearly suggests a requirement of Ltbp-4L for postnatal survival. A major difference between Ltbp4S−/− and Ltbp4−/− mice is the matrix incorporation of fibulin-4 (a key factor for elastogenesis; encoded by the Efemp2 gene), which is normal in Ltbp4S−/− mice, whereas it is defective in Ltbp4−/− mice, suggesting that the presence of Ltbp-4L might be required for this process. To investigate the existence of a functional interaction between Ltbp-4L and fibulin-4, we studied the consequences of fibulin-4 deficiency in mice only expressing Ltbp-4L. Resulting Ltbp4S−/−;Fibulin-4R/R mice showed a dramatically reduced lifespan compared to Ltbp4S−/− or Fibulin-4R/R mice, which survive to adulthood. This dramatic reduction in survival of Ltbp4S−/−;Fibulin-4R/R mice correlates with severely impaired elastogenesis resulting in defective alveolar septation and distal airspace enlargement in lung, and increased aortic wall thickness with severely fragmented elastic lamellae. Additionally, Ltbp4S−/−;Fibulin-4R/R mice suffer from aortic aneurysm formation combined with aortic tortuosity, in contrast to Ltbp4S−/− or Fibulin-4R/R mice. Together, in accordance with our previous biochemical findings of a physical interaction between Ltbp-4L and fibulin-4, these novel in vivo data clearly establish a functional link between Ltbp-4L and fibulin-4 as a crucial molecular requirement for survival and elastogenesis in mice., Summary: The interaction of the long form of latent-transforming growth factor beta-binding protein 4 and fibulin-4 is essential for survival as well as for the formation of elastic fibers.

The Valiant Navion stent graft system (Medtronic, Santa Rosa, Calif) is a new iteration of a thoracic endograft for the treatment of descending thoracic aortic aneurysms. Herein, the 30-day primary safety and efficacy outcomes and secondary end points are presented.The Valiant EVO global clinical trial is a prospective, nonrandomized, single-arm trial. Patient enrollment occurred from April 2016 to October 2017. The primary end point was defined as access and/or deployment failure and/or a major device effect (MDE), including device-related secondary procedures, device-related mortality, conversion to open surgery, or thoracic aortic aneurysm rupture within 30 days of the index procedure. Other measures of stent graft performance including procedural data, rates of secondary procedures, and frequency of endoleaks are also reported.Of the 87 consecutive patients undergoing thoracic endovascular aneurysm repair who were enrolled, 33 (37.9%) were female with 61 (70.9%) presenting with severe access artery tortuosity and 66 (85.7%) with high thoracic aortic tortuosity per core laboratory evaluation. The mean procedure duration was 88.7 ± 53.4 minutes and geographical differences existed such as percutaneous access (37/52 [71.2%]) in the United States and surgical cut down in the outside of the U.S. sites (28/35 [80.0%]). There were no access or deployment failures and only 2.3% of the patients (2/87; P .0001; performance goal of 16%) experienced a MDE within 30 days of the index procedure. Two secondary procedures (n = 1 retrograde type A dissection; n = 1 aortic arch rupture) were required, and in the first 30 days, two patients died leading to a freedom from all-cause mortality of 97.7%. Endoleaks at 1 month were reported in 2.5% of patients (n = 1 type Ia; n = 1 type II).Access/deployment failures, MDEs, and endoleaks were rare in the first 30 days of the Valiant Evo clinical trial. The Valiant Navion thoracic stent graft system has shown encouraging 30-day results in this challenging cohort and trial patients will continue to be followed through 5 years.

at the 2011ASME 6th Frontiers Biomedical Device Conference 23 they used three representative patient abdominal aneurysm models with varying aortic tortuosity and decreased proximal neck length. They are using a simplified stent graft model with a single cylindrical tube for the graft and with z-based stents on the inside of the graft. With the incorporation of fluid flow and representative pulsatile forces they coupled their mechanical based analysis, including friction, with the fluid dynamics. Their simulation approach induces a pre-stress in the artery to represent the in-vivo mean arterial pressure load. Though the research here is not focused on modeling methodology or clinical relevance it is the foundation for such work. And, though we cycled our devices though complete compression-decompression to get the dynamics of the graft, undoubtedly, one can resolve that in-vivo the graft would never collapse until complete occlusion unless a material failure occured. It may be that in equilibrium with the artery the device displays a non-concentric based deformed shape, possibly an elliptical one. Yet the ability to tie our experimental or modeled data of a pressure induced compression to the interface pressure of the stent graft is difficult. At best, one may only draw an estimated amount of interface pressure at the low end of the device compression from our data. This is because the oversizing selection of devices is based on circular cross-sections while our data is elliptical in nature and was mathematically mapped back to the equivalent circular diameter. Yet, the pursuit of this work was to formulate an experimental methodology that captured the radial compressive behavior of endovascular devices. We then set out to leverage our ability to attain that data and build a computational stent based model whose geometry was realistic and whose dynamics approximate the average compressive nature of the device. Our results suggest that the developed model is representative of our experiments and the model may be used to interrogate how a SG will perform during

Treatment of thoracic aortic dissection remains highly challenging and is rapidly evolving. Common classifications of thoracic aortic dissection include the Stanford classification (types A and B) and the DeBakey classification (types I to III), as well as a new supplementary classification geared toward endovascular decision making. By using various imaging techniques, the extent of the dissection, the location of the primary intimal tear, the shape of the aortic arch, and the zonal involvement of the aortic arch-factors that affect the treatment strategy-can easily be identified. Thoracic endovascular aortic repair (TEVAR) is generally performed in two groups of patients: (a) those with a surgically repaired type A dissection, and (b) those with a complicated type B dissection. Several imaging findings can help predict the course of remodeling of the dissected aorta after a repaired type A dissection and TEVAR. A spectrum of imaging findings exist with regard to favorable (positive) or failing (negative) remodeling. A schematic model with imaging support allows the classification of important causes of failing remodeling into proximal and distal groups, on the basis of the origin of the refilling of the false lumen and the underlying pathophysiology of pressurization. Refilling of the false lumen of the aorta after repair of a type A dissection is usually secondary to a persistent intimal tear at the aortic arch, a leak of the distal graft anastomosis, or refilling from the false lumen of a dissected aortic arch vessel. After TEVAR, false lumen refilling is most commonly due to an incomplete seal of the proximal landing related to the aortic tortuosity, an arch branch stump, a supra-arch chimney stent, or the TEVAR technique. Online supplemental material is available for this article. ©RSNA, 2018.

Background Surgical management of aortic arch pathologies is complex, and endovascular developments have now enabled total or hybrid endovascular aortic arch repair. We present our early experience with fenestrated aortic arch repairs in Ishimaru zones 1 and 2 pathologies. Methods In a single tertiary institution, all consecutive endovascular aortic arch repairs were reviewed. A preoperative computed tomography aortogram was performed to assess anatomic suitability, which we defined as having a proximal sealing zone with a maximum diameter of 38 mm and minimum length of 20 mm, absence of significant aortic tortuosity, and suitable sealing zones in target vessels. Results From September 2015 to February 2018, 5 cases of fenestrated aortic arch endovascular repairs were performed. There were 3 male patients. The patients were between 57 and 83 years old, all of whom were American Society of Anesthesiologists (ASA) class II or III. Indications for surgery included aortic arch aneurysms (n = 3), a symptomatic aortic dissection, and a left subclavian artery aneurysm. Three patients had a scallop to the innominate artery, and one patient had a scallop to the left common carotid artery. Fenestrations were made to 3 left common carotid arteries and 3 left subclavian arteries. In 2 patients, a left carotid–subclavian bypass was performed, and the left subclavian artery origin occluded with a vascular plug. Technical success was 100%. One patient developed a right occipital infarct and acute myocardial infarction. The mean duration of surgery was 164 min, and the mean length of stay was 4.2 days. The mean follow-up period was 14.4 months. Conclusions The use of fenestrated grafts in the aortic arch is a feasible treatment option. However, certain limitations still exist, and preoperative planning is important in ensuring clinical success. Although this procedure appears feasible in the short term, long-term results and durability remain to be seen.

Background: Patients with Marfan syndrome (MFS) have a highly variable occurrence of aortic complications. Aortic tortuosity is often present in MFS and may help to identify patients at risk for aortic complications.Methods: 3D-visualization of the total aorta by MR imaging was performed in 211 adult MFS patients (28% with prior aortic root replacement) and 20 controls. A method to assess aortic tortuosity (aortic tortuosity index: ATI) was developed and reproducibility was tested. The relation between ATI and age, and body size and aortic dimensions at baseline was investigated. Relations between ATI at baseline and the occurrence of a clinical endpoint (aortic dissection, and/or aortic surgery) and aortic dilatation rate during 3 years of follow-upwere investigated.Results: ATI intra-and interobserver agreements were excellent (ICC: 0.968 and 0.955, respectively). Mean ATI was higher in 28 age-matched MFS patients than in the controls (1.92 +/- 0.2 vs. 1.82 +/- 0.1, p = 0.048). In the total MFS cohort, mean ATI was 1.87 +/- 0.20, and correlated with age (r=0.281, p 1.95 had a 12.8 times higher probability of meeting the combined endpoint (log rank-test, p Conclusions: Increased ATI is associated with a more severe aortic phenotype in MFS patients. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

Aortic tortuosity is often found on chest radiograph, especially in aged patients. We tested the hypothesis that aortic tortuosity was associated with LV diastolic parameters derived from gated SPECT in patients with normal myocardial perfusion. One-hundred and twenty-two patients with preserved LV ejection fraction and normal myocardial perfusion were enrolled. Descending aortic deviation was defined as the horizontal distance from the left line of the aortic knob to the most prominent left line of the descending aorta. This parameter was measured for the quantitative assessment of aortic tortuosity. Peak filling rate (PFR) and one-third mean filling rate (1/3 MFR) were obtained from redistribution images as LV diastolic parameters. Descending aortic deviation ranged from 0 to 22 mm with a mean distance of 4.5 ± 6.3 mm. Descending aortic deviation was significantly correlated with age (r = 0.38, p

Introduction The risk of type A aortic dissection (AAD) depends on the degree of aortic wall's alteration, which can result in dilatation and tortuosity. The estimate of this risk currently relies solely on measuring the diameter of the ascending aorta. Objective The purpose of this study is to ascertain that patients with AAD don’t have higher aortic tortuosity, and more liver or renal cysts. Method We analyzed aortic scans of 109 patients with AAD after surgery and 109 control patients matched on gender and age. After 3D reconstruction, the total and geometrical lengths (Ltot and Lgeo) of the different aortic segments were measured to calculate the aortic index of tortuosity (IT = Ltot/Lgeo). Results The different aortic segments of the AAD group have higher Ltot, Lgeo and IT than the control group. For the whole aorta, the mean Ltot is 527.7 ± 46.1 mm for the AAD group versus 475.8 ± 39.7 mm for the control group, i.e. 9.4% longer (P Fig. 1 ). For the whole aorta with exclusion of the ascending part, ie non-operated aorta, the threshold value of the IT at 1.303 makes it possible to discriminate AAD patients in our population with a sensitivity of 69.7% and a specificity of 79.8%, i.e. an accuracy of 74.8% (AUC = 0.792, P Conclusion Patients with AAD have a longer and more tortuous aorta and also more liver or renal cysts. Aortic tortuosity is favored by presence of cysts, hypertension, age and warned by diabetes. A new study is needed to confirm that the higher the Ltot, IT and the number of cysts are, the higher the risk of AAD is; and also that our threshold value of IT2 at 1.303 could be associated with the measurement of the diameter aortic for discussion of prophylactic AAD surgery.

ObjectivesThis study sought to identify possible anatomic predictors of acute type B aortic dissection (AAD) in hypertensive patients using multidetector computed tomography angiography (CTA).BackgroundAlthough hypertension remains one of the most significant risk factors for AAD development, it is unlikely to be the only risk factor for AAD. Few studies have assessed anatomical predictors of AAD development.MethodsCTA of normotensive patients without AAD (group 1, n = 35), hypertensive patients without AAD (group 2, n = 37), and hypertensive patients with AAD (group 3, n = 37) were compared. The length, diameter, volume, and tortuosity of the aorta as well as arch vessel angulation were measured for each patient and normalized to group 1 averages. Stepwise logistic regression identified significant anatomical associations; the model was validated based on 1,000 bootstrapped samples.ResultsThe demographics of the groups were similar. The length of the proximal and entire aorta, the diameters in the proximal ascending aorta and aortic arch, and the aortic volumes were all greater (p < 0.0001, p = 0.0064 for ascending aortic diameter) in group 3 than in groups 1 and 2, as was entire aortic tortuosity (p < 0.0001). An AAD risk model was developed based on aortic arch diameter, length from the aortic root to the iliac bifurcation, and angulation of the brachiocephalic artery origin from the aorta. The bootstrap estimate of the area under the receiver operating curve was 0.974.ConclusionsEnlargement of the ascending aorta and aortic arch and increased aortic tortuosity reflect an aortopathy which enhances the probability of AAD. A model based on 3 anatomical variables demonstrates significant associations with AAD: it may allow identification by aortic imaging of the hypertensive patient most at risk, and permit implementation of aggressive medical management and consideration of pre-emptive surgery to prevent dissection.

Background Technical and clinical success of thoracic aortic endovascular procedures relies mainly on the choice of the proximal sealing zone (PSZ). The latter can be affected by multiple complications, all of them having a potential gravity and a direct link with the quality of the PSZ. The objective of this study was to analyze the risk factors of PSZ complications occurrence. Methods Between 2007 and 2015, all the patients treated by a thoracic stent graft in zones 2, 3, or 4 were retrospectively reviewed, with analysis of the preoperative and postoperative angio-computed tomography. Proximal sealing zone complications are type Ia endoleaks, bird beak ≥20 mm, malposition ≥11 mm, migration ≥10 mm, and retrograde dissection. Three types of potential risk factors were analyzed: (1) related to the patients (age, gender, pathology, urgency, hybrid surgery); (2) related to the stent graft (bare or covered proximal stent, degree of oversizing, number of stents, generation); (3) related to the morphology (radius of curvature, diameter, degree of conicity, calcifications and thrombus of the neck, depth of the arch, angulation of the proximal sealing zone, and tortuosity index of the arch and the thoracic aorta. Results Seventy-six patients (mean age: 54 years, 17–93 years) were treated for traumatic aortic rupture (n = 27, 35.5%), aortic dissection (n = 26, 34%), aneurysm (n = 15, 20%), and other diseases (floating thrombus, aortoesophageal fistula) (n = 8, 10.5%). A hybrid surgery was carried out in 18 patients (24%). Primary technical success was 93.5% (n = 71). With a mean follow-up of 29 months, 30 PSZ complications were observed in 21 patients (28%): type Ia endoleaks (n = 3, 4%), bird beak (n = 7, 9%), malposition (n = 3, 4%), migration (n = 1, 1.5%), retrograde dissection (n = 1, 1.5%), or several complications (n = 6, 7.8%). Among the morphological factors, 2 parameters were significantly associated with the occurrence of complications: tortuosity index (group without PSZ complications 1.62 ± 0.2 vs. group with PSZ complications 1.72 ± 0.2, P = 0.042), and the diameter of the proximal neck (group without PSZ complications 25.7 ± 5 vs. group with PSZ complications 31 ± 6.0, P = 0.001). Neither the demographic factors nor those related to the stent graft presented a statistically significant relation with the occurrence of complications. Conclusions This work clearly highlights the relation between PSZ complications, independently of their type, and the local and global aortic morphology. A wide proximal neck, > 34 mm, and an important aortic tortuosity, > 1.8, are situations at risk.

Background Endovascular aneurysm repair (EVAR) becomes the treatment of choice for patients with abdominal aortic aneurysm (AAA). Type I or III endoleak is related to high risk of rupture and reintervention, but little is known about the delayed presentation of these. We sought to evaluate the delayed type I or III endoleak after EVAR and assess the early morphological portending factors. Methods We retrospectively reviewed a database of 249 patients who underwent endovascular repair with a Zenith AAA stent graft (Cook Medical, Bloomington, IN) in a single institute from October 2005 to December 2013. Age, aneurysm size, angulation, tortuosity index (TI), and follow-up evaluations were recorded and analyzed. Patients having Results One hundred eighteen patients were included in this study. There was no delayed type Ia endoleak. Ten patients (9.3%) were found to have a delayed type Ib or III endoleak. The mean diagnosis time was 49.1 months (range, 22–91 months) after EVAR. All of them were treated with endovascular repair except one had combined open revision. Three of the patients (30%) with delayed endoleaks presented with a ruptured aneurysm, and two of them (20%) died after reintervention. Postoperative TI was found to be the most significant morphological factor associated with increased risk of type Ib or III endoleak. Conclusions Delayed type Ib or III endoleak was not rare in our study population and was found to have a high risk of rupture and mortality. Aneurysm tortuosity is associated with increased risk of endoleaks, and postoperative TI can be an indicator in the early period of follow-up.

Transcatheter aortic valve implantation is an alternative therapy for surgery in patients with aortic stenosis having high risk for surgery. Transcatheter aortic valve implantation may be performed through transfemoral, transaortic and transapical approaches. General anesthesia is generally required for transapical and transaortic approaches while epidural anesthesia is enough for the transfemoral approach. Although transfemoral access is suitable for most cases, patients having severe vascular tortuosity are candidates for the transapical approach. However, the approach for patients having vascular tortuosity along with poor respiratory capacity contraindicated for general anesthesia is controversial. Vascular complications that significantly increase patient morbidity and mortality are common in transfemoral transcatheter aortic valve implantation and generally associated with severe ilio-femoral tortuosities, severe calcification, porcelain aorta, and significant atheroma of the femoral and iliac vessels. But the effect of tortuosity alone was not evaluated well and complications were generally associated with vascular calcification. Stiff wires were commonly used in endovascular procedures. The vascular tortuosity can be straightened with stiff wires but the accordion effect, pseudo obstruction and vascular injury may also be observed. Herein we present a case of severe aortic stenosis successfully treated with transfemoral aortic valve implantation despite severe femoral, iliac and aortic tortuosity having severe chronic obstructive pulmonary disease.

The objective of our study was to assess whether there is an association between native thoracic aortic curvature and the development of endoleaks after thoracic endovascular aortic repair.Quantitative analysis of the native aortic lumen was performed on preprocedural CT angiograms of 40 patients with thoracic aortic aneurysm treated by thoracic endovascular aortic repair. The curvature of the median centerline was measured. Tortuosity indexes were calculated on the basis of the sum of the curvature values within the diseased segment and in the proximal and distal fixation zones. The association between the tortuosity index and endoleak was analyzed.Compared with patients without endoleaks, the tortuosity index of the proximal fixation zone was higher in patients with type Ia endoleak (9.5 vs 1.5 cm(-1), p0.01); the tortuosity index of the distal fixation zone was higher in type Ib endoleak patients (6.6 vs 0.5 cm(-1), p0.05); and the tortuosity indexes of the proximal fixation zone and of the diseased segment were higher in type III endoleak patients (11.0 vs 1.5 cm(-1), p0.01; and 15.8 vs 7.2 cm(-1), p0.01, respectively). Patients with a type III endoleak had longer diseased segments and larger mean diameters of the aneurysm than patients without endoleaks (148.6 vs 87.1 mm, p0.01; and 75.4 vs 63.2 mm, p0.05, respectively). Logistic regression analysis revealed that the risk of a type I or type III endoleak increased as the tortuosity index increased, with a 90% risk of endoleak at a tortuosity index of 10 cm(-1) in the proximal fixation zone.Quantification of aortic tortuosity using CT angiograms may help to predict whether an endoleak will develop after thoracic endovascular aortic repair, and this quantification method may become an important tool for risk stratification before thoracic endovascular aortic repair.

Bicuspid aortic valve (BAV) is associated with aortic aneurysms and dissections. Aortic tortuosity predicts dissection in other congenital aortopathies like Marfan syndrome. We hypothesize that increased aortic tortuosity can also predict adverse outcomes in BAV patients. BAV patients with chest CT

Thorough imaging of the aortic valve and related structures is highly important before and during percutaneous valve implantation. However, imaging modalities currently used in the catheterization room, namely, conventional aortography and transesophageal echocardiography are limited in guiding the precise valve placement during the implantation procedure. A novel real-time imaging modality capable of three-dimensional reconstruction of the ascending aorta has recently been introduced (CardioOpTHV, C-THV, Paieon Inc., Park Afek, Israel). We applied this system during a complex procedure of percutaneous aortic valve implantation in a patient with severe aortic tortuosity, large aortic-valve angulation, and asymmetric septal hypertrophy. We found the guidance system very helpful not only for accurate positioning of the valve but also for selecting the optimal projection for valve implantation, selecting the prosthetic valve size, and evaluating the results after deployment. V C 2010 Wiley-Liss, Inc.

Imaging description In patients with tortuous aortas due to aging or atherosclerotic disease, measurements of aneurysm on axial images can lead to falsely elevated aneurysm diameters. Figure 65.1 shows an axial CT image of the ascending thoracic aorta in a 64-year-old woman, which measured 3.9cm. However, when the aneurysm is evaluated on double oblique, sagittal, and coronal multiplanar reformatted images (MPRs), it becomes apparent that the actual size is 3.5cm. The thoracic aorta has a candycane configuration, which may necessitate measurements using MPRs to accurately determine the cross-sectional diameter. Similarly, Figure 65.2 shows a 64-year-old man with an abdominal aortic aneurysm, the course of which is not entirely perpendicular to the z-axis of the scan. Accordingly, to accurately determine the diameter, the measurements must be made on MPRs tailored to reflect the actual cross-sectional diameter perpendicular to the aortic centerline. Importance One of the primary roles of CT in the patient with aortic aneurysm is aneurysm measurement, as the risk of rupture directly correlates with aneurysm size. Surgical thresholds have been defined based on anatomic segment. For the ascending thoracic aorta it is 5.5cm, for descending thoracic aorta 6.5cm, and for abdominal aorta 5.5cm. Serial imaging is critical to evaluate for rate of growth, an additional risk factor that reflects an increased risk of rupture. Aneurysms that grow more than 5–7mm in 6 months or 1cm in one year are considered rapidly enlarging and may warrant repair. Accordingly, accurate methods of measurement are critical to patient management. As shown in this case, axial CT images should not be relied upon for thoracic aortic and abdominal aortic aneurysm measurements. Tortuosity of the aorta results in a course that is no longer directly perpendicular to the axial plane. In these cases, MPRs or 3D renderings are required to generate accurate bi-dimensional aneurysm measurements orthogonal to the aortic lumen centerline. Either manual double oblique MPRs or short-axis images generated from software-based automated centerline tracking are recommended for the most reliable aneurysm measurement.

Recent reports have documented poor long-term results following endovascular aneurysm repair (EVAR) of large abdominal aortic aneurysms (AAA). EVAR of small AAAs may result in improved long-term results compared to large AAAs. It is not known whether the frequency of anatomic suitability for EVAR is increased for small compared to large AAAs. This study compared the anatomic suitability of large and small AAAs for EVAR in an unselected patient population. Radiology reports for all computed tomography (CT) scans in a single hospital over a recent 3-year period were reviewed. AAAs diagnosed by contrasted CT scans with cuts >7 mm were excluded. Suitability for EVAR was determined by neck diameter, length, and angulation. In addition, iliac diameters and common iliac distal landing zone lengths were determined. Computerized 3-dimensional (3D) reconstruction was used to measure neck angulation and total aortic tortuosity. One hundred ninety-one patients were found to have AAAs with adequate CT scans for evaluation. Suitability for EVAR was highest in patients with AAA diameters of 3–4 cm and declined with increasing size of the AAA. Dividing AAAs into sizes greater than or less than 5.5 cm revealed that small AAAs had significantly longer necks, less neck angulation, longer common iliac landing zones, and less total aortic tortuosity. Multivariable analysis revealed that maximal aortic diameter was the only independent predictor of suitability for EVAR (p = 0.005, odds ratio 1.67, CI 95% = 1.17 to 2.38). The odds ratio predicts that with each 1 cm increase in size, the likelihood of suitability decreased by 5.3-fold. Small AAAs have less complex anatomy with longer aortic necks, less neck angulation, and less tortuosity. The poor outcomes following the treatment of large AAAs is thought to be due to complex anatomy. EVAR of less anatomically challenging small AAAs may improve longterm outcomes.

Although Bochdalek hernia is the most common congenital diaphragmatic hernia in adults, bilateral occurrence is rare. To the best of our knowledge, only case reports on Bochdalek hernia and its associated pathologies have been previously published. Herein, we present the case of a 27-year-old man with bilateral Bochdalek hernias, which were detected incidentally. The bilateral Bochdalek hernias were found to be associated with severe aortic tortuosity and aberrant right subclavian artery.

We described four offspring of a consanguineous couple with arterial tortuosity "syndrome" (ATS). The affected children had extensive arterial involvement although the clinical presentations were quite variable. Clinical manifestations included cutis laxa or soft/thin skin, joint laxity or contractures, and arachnodactyly. Aortic tortuosity and pulmonary artery aneurysms with or without peripheral stenoses were demonstrated in all four sibs. All three males had inguinal hernias. Inconsistent facial anomalies were downslanting palpebral tissues, beaked nose, micrognathia, and high-arched palate. Results of collagen type I and type III biosynthesis studies were normal on skin fibroblasts. Histologic findings on autopsy of one affected child showed arterial changes with disruption of elastic fibers of the media and fragmentation of the internal elastic membrane as well as mucosal and transmural necrosis of the stomach, small bowel, colon, and extensive necrosis of the liver. Coronary artery involvement was also seen in this child as well as biventricular hypertrophy. We conclude that ATS is an autosomal recessive connective tissue condition associated with diffuse arterial changes and involvement of the skin, joints, and other organs.

Superior mesenteric artery (SMA) syndrome is a rare cause of duodenal obstruction due to compression of the third part of duodenum between SMA and aorta. Clinical suspicion and radiological findings are playing important role in the diagnosis of SMA syndrome. We report here the clinicoradiologic findings in a case of 66-year-old Indian male. In our case, abdominal aortic tortuosity in an elderly patient was the cause for SMA syndrome.

OBJECTIVES: To investigate mid-term outcome in patients undergoing thoracic endovascular aortic repair (TEVAR) for non-dissected aortic pathology with favourable and unfavourable landing zone and aortic anatomy. METHODS: Between 2000 and 2011, TEVAR was performed in 208 patients with descending thoracic aortic disease. Of 105 patients with non-dissected thoracic aortic pathology, 69 presented with unfavourable anatomy as defined by short length ( 42 mm), angulation of >60° of the proximal or distal landing zone or extreme aortic tortuosity. The endpoints perioperative mortality, 1-year survival, endoleak occurrence and incidence of secondary intervention were compared with the remaining 36 patients with favourable anatomy. RESULTS: Median follow-up was 18 months. TEVAR was performed emergently in 24 of 69 (35%) patients with unfavourable anatomy and in 11 of 36 (31%) of those with favourable anatomy (P= 0.68). No patients underwent conversion to open surgery, no periinterventional rupture was observed. Perioperative mortality did not differ between cohorts (1/69 vs 1/36, P= 0.78). Postoperative permanent spinal cord ischaemia occurred in patients with unfavourable anatomy only (2/69 vs 0/36, P= 0.78). Early endoleak and secondary intervention were more frequent in patients with unfavourable anatomy (19/69 vs 7/36 and 13/69 vs 1/36), but not statistically significant (P= 0.5 and P= 0.13, respectively). One-year aorta-related survival rates were similar in both groups (66/69 vs 33/36, P= 0.45). CONCLUSIONS: Mid-term outcome after TEVAR does not differ between patients with favourable and unfavourable landing zone anatomy in terms of aorta-related survival. However, the more frequent need for secondary intervention warrants a more rigorous follow-up after TEVAR in patients with unfavourable anatomy.

Anatomical variation in the visceral aortic segment is considerable. The celiac trunk follows the classical configuration in only 50 % of cases. The SMA, typically arising approximately 1 cm distal to the celiac artery, may also originate as a celiac-mesenteric trunk, or together with the splenic artery. The renal arteries typically arise at approximately the same level as each other, and usually but not always, distal to the level of the SMA. Each kidney is supplied by a single hilar artery in as few as 55 % of cases, with accessory arteries, double hilar arteries and single arteries with precocious bifurcation being the most common variations. To take account of such individual disparity, often accentuated by aortic tortuosity and aneurysmal distortion, fenestrated stent grafts which allow for preservation of aortic side branches are by necessity custom-made on an individual patient basis.