Supra-aortic Branches Research Articles

Anatomical Variations in Aortic Arch Branching Pattern: A Computed Tomography Angiography Study.

Variations in the branching pattern of the aortic arch (AA) are common. Modification of intravascular stents should be considered taking into account these AA branching variations. Identification of supra-aortic branching types and frequencies is important for specialists planning surgery in this region.In endovascular interventions to the AA, aortic stent grafts should be modified according to the variations of the branching patterns of the AA.In any surgical intervention to the region where the supra-aortic branches are located, ignorance of the variations may cause unwanted injuries or complications. In this study, 699 computed tomography angiography (CTA) images were reviewed to investigate AA branching variations using the Horos software (an open-source image viewer). Four groups were constructed based on the number of branches emerging from the aortic arch, which were further divided into subtypes. A total of 699 CTA images from 320 males and 379 females were included in this study. The usual AA branching pattern (type 3b1) was found in 68.5% of the patients. The combined prevalence of other eight branching patterns, designated as variations, was 31.5%. Variation types 1b1, 3b2, and 4b5 were identified in one patient each. Overall, types 2b1 and 2b2 had a prevalence of 28.3%. The type 2b3 variation was observed in 1.6% of the patients. The least common variations were type 4b1 (0.7%) and type 3b2 (0.1%). The identification of variations in AA branching patterns by CTA prior to surgical or endovascular interventions involving the aortic arch is important. Thus, specialists planning interventions in this region need to be aware and have knowledge of atypical aortic branching patterns. Higher prevalence rates of AA branching patterns compared to previous studies were identified in the Turkish population in this study and therefore, a comprehensive, multicenter study is needed to determine the cause of this differential finding.

Komplex endovascularis rekonstrukciók az aortaíven.

Thoracic endovascular aneurysm repair (TEVAR) of the aortic arch has started to spread in recent years. We present our initial experience with TEVAR involving supra-aortic branches using parallel and branched grafts. Parallel grafts are typically used in emergency cases. In the case of Z0 proximal fixation, we can perform a combined hybrid surgery with Z1 debranching and securing of the innominate artery with chimney graft, which can also be used instead of Z0 debranching when the patient is unfit for sternotomy. In the case of TEVAR with planned Z2 position with inadvertent covering of the left common carotid artery, we can perform chimney conversion to rapidly recover the circulation of the left common carotid artery (LCCA). Instead of prior revascularization of the left subclavian artery, chimney graft can be used to recover the lumen, in the case of left upper limb ischemia after Z2 TEVAR. Exclusion of penetrating aortic ulcers located in the lesser curvature can be facilitated by use of a custom-made graft, where a scallop is placed around the origin of the supra-aortic vessel, thus increasing the length of the proximal neck. For elective interventions, custom-made branching grafts can be allowed to save all three branches with Z0 fixation. Technical success was obtained in all cases. Orv Hetil. 2023; 164(11): 426-431.

Endovascular repair of aortic pathologies involving the aortic arch using castor stent-graft combined with in-vitro fenestration technology

BackgroundAortic arch pathologies are concerning clinical conditions with poor prognoses. The use of thoracic endovascular aortic repair (TEVAR) has been investigated to treat aortic arch pathologies. Nonetheless, cerebral blood flow regulation during endovascular aortic arch repair therapy remains challenging. Castor, a unique single-branched stent graft, has been proven effective for retaining the left subclavian artery (LSA). This study aimed to determine whether endovascular therapy for pathologies involving the aortic arch using Castor in combination with the in-vitro fenestration technique is promising, effective, and safe.MethodsEligible patients were enrolled between June 2018 and December 2021. All patients underwent TEVAR with an evaluated proximal landing zone for “Castor” located in Ishimaru zones 0–1. Moreover, the supra-aortic branches (SABs) were reconstructed using the Castor in combination with the in-vitro fenestration technique.ResultsHerein, 57 patients with aortic arch lesions were treated with Castor in combination with the in-vitro fenestration technique. Innominate artery and the left carotid artery (LCA) were reconstructed in 5 patients, LCA and left subclavian artery (LSA) were reconstructed in 22 patients, and the total SABs were effectively reconstructed in 30 patients (including a hybrid arch repair case). Among them (excluding a hybrid arch repair case) were in-vitro fenestration methodologies for LCA in 32 of 34 cases (2 switched to in-situ fenestration) and LSA in 51 of 56 cases (3 switched to in-situ fenestration and 2 converted to spring coil caulking); furthermore, LCA and LSA in-vitro fenestration were simultaneously successfully performed in 27 of 34 cases. There were no surgical-related neurological complications, and early mortality was estimated at 5.26%. At a mean follow-up of 3.75 months, computed tomography (CTA) images confirmed that each branch stent remained patent. There were no signs of endoleaks, migrative manifestations, or the need for secondary endovascular intervention or conversion to open surgical procedures.ConclusionCastor, in combination with in-vitro fenestration, reflects a feasible, efficient procedure for re-developing SABs.

Endovascular aortic arch repair with chimney technique for pseudoaneurysm

BackgroundAortic pseudoaneurysm is a life-threatening clinical condition, and thoracic endovascular aortic repair (TEVAR) has been reported to have a relatively satisfactory effect in aortic pathologies. We summarized our single-centre experience using chimney TEVAR for aortic arch pseudoaneurysms with inadequate landing zones.MethodsA retrospective study was conducted from October 2015 to August 2020, 32 patients with aortic arch pseudoaneurysms underwent chimney TEVAR to exclude an aortic lesion and reconstruct the supra-aortic branches, including 3 innominate artery, 12 left common carotid arteries and 29 left subclavian arteries. Follow-up computed tomography was suggested before discharge; at 3, 6, 12 months and yearly thereafter.ResultsThe median age of 32 patients was 68.0 years (range, 28–81) with the mean max diameter of aneurysm of 47.9 ± 12.0 mm. Forty-four related supra-aortic branches were well preserved, and the technical success rate was 100%. The Type Ia endoleaks occurred in 3 (9%) patients. Two patients were lost to follow-up and 4 patients died during the follow-up period. The mean follow-up times was 46.5 ± 14.3 months. One patient died due to acute myocardial infarction just 10 days after chimney TEVAR and the other 3 patients passed away at 1.5 months, 20 months, and 31 months with non-aortic reasons. The 4.5-year survival estimate was 84.4%. The primary patency rate of the target supra-arch branch vessels was 97.7% (43/44), and no other aorta-related reinterventions and severe complications occurred.ConclusionFor aortic arch pseudoaneurysms with inadequate landing zones for TEVAR, the chimney technique seems to be feasible, with acceptable mid-term outcomes, and it could serve as an alternative minimally invasive approach to extend the landing zone. Slow flow type Ia endoleak could be treated conservatively after chimney TEVAR. Additional experience is needed, and the long-term durability of chimney TEVAR requires further follow-up.

Analysis of Postoperative Remodeling Characteristics after Modular Inner Branched Stent-Graft Treatment of Aortic Arch Pathologies Using Computational Fluid Dynamics

The modular inner branched stent-graft (MIBSG), a novel interventional therapy, has demonstrated good effects in the endovascular treatment of aortic arch pathologies, especially those involving the supra-aortic branches. Nevertheless, the long-term efficacy of the MIBSG and in-depth quantitative evaluation of postoperative outcomes remain to be examined. Moreover, the regularity of postoperative vascular remodeling induced by MIBSG implantation has yet to be explored. To address these questions, we constructed four models (normal, preoperative, 1 week postoperative, and 6 months postoperative) based on a single patient case to perform computational fluid dynamics simulations. The morphological and hemodynamic characteristics, including the velocity profile, flow rate distribution, and hemodynamic parameter distribution (wall shear stress and its derivative parameters), were investigated. After MIBSG implantation, the morphology of the supra-aortic branches changed significantly, and the branch point moved forward to the proximal ascending aorta. Moreover, the curvature radius of the aortic arch axis continued to change. These changes in morphology altered the characteristics of the flow field and wall shear stress distribution. As a result, the local forces exerted on the vessel wall by the blood led to vessel remodeling. This study provides insight into the vascular remodeling process after MIBSG implantation, which occurs as a result of the interplay between vascular morphological characteristics and blood flow characteristics.

Tips and tricks about surgeon-modified fenestrated stent grafting for celiac truncus.

Currently, thoracic endovascular aortic repair is usually the first-line treatment option for descending aortic pathologies. Supra-aortic or visceral branches sometimes involve assistive thoracic endovascular aortic repair techniques; hybrid procedures or intentional coverage may be performed during the procedure to achieve a sufficient proximal or distal landing zone. Most surgeons may agree on selective coverage of celiac truncus, but revascularization is preferred to reduce the risk of ischemic complications. Herein, we present the first successful surgeonmodified fenestrated stent graft procedure for celiac truncus in a patient with Crawford type V descending aortic aneurysm in Türkiye.

Irregular anatomical features can alter hemodynamics in Takayasu arteritis

ObjectiveTakayasu arteritis (TA) is a difficult disease to deal with because there are neither reliable clinical signs, laboratory biomarkers, nor a single noninvasive imaging technique that can be used for early diagnosis and disease activity monitoring. Knowledge of aortic hemodynamics in TA is lacking. This study aimed to fill this gap by assessing hemodynamics in patients with TA using image-based computational fluid dynamics (CFD) simulations. MethodsEleven patients with TA were included in the present study. Patient-specific geometries were reconstructed from either clinical aortic computed tomography angiography or magnetic resonance angiography studies and coupled with physiological boundary conditions for CFD simulations. Key anatomical and hemodynamic parameters were compared with a control group consisting of 18 age- and sex-matched adults without TA who had healthy aortas. ResultsCompared with controls, patients with TA had significantly higher aortic velocities (0.9 m/s [0.7, 1.1 m/s] vs 0.6 m/s [0.5, 0.7 m/s]; P = .002), maximum time-averaged wall shear stress (14.2 Pa [9.8, 20.9 Pa] vs 8.0 Pa [6.2, 10.3 Pa]; P = .004), and maximum pressure drops between the ascending and descending aorta (36.9 mm Hg [29.0, 49.3 mm Hg] vs 28.5 mm Hg [25.8, 31.5 mm Hg]; P = .004). These significant hemodynamic alterations in patients with TA might result from abnormal anatomical features including smaller arch diameter (20.0 mm [13.8, 23.3 mm] vs 25.2 mm [23.3, 26.8 mm]; P = .003), supra-aortic branch diameters (21.9 mm [18.5, 24.6 mm] vs 25.7 mm [24.3, 28.3 mm]; P = .003) and descending aorta diameter (14.7 mm [12.2, 16.8 mm] vs 22.5 mm [19.8, 24.0 mm]; P < .001). ConclusionsCFD analysis reveals hemodynamic changes in the aorta of patients with TA. The applicability of CFD technique coupled with standard imaging assessments in predicting disease progression of such patients will be explored in future studies. Future large cohort study with outcome correlation is also warranted. Clinical RelevanceBased on patient-specific computational fluid dynamics simulations, the present retrospective study revealed significant difference in aortic hemodynamics between the patients with and without Takayasu arteritis (TA). To the best of our knowledge, this study is the first to evaluate hemodynamic conditions within TA, demonstrating the potential of computational flow modeling in capturing abnormal hemodynamic forces, such as high wall shear stress, resulted from irregular morphological changes. In the future, assessing the hemodynamic parameters within patients with TA during the prestenotic period, together with longitudinal computational fluid dynamics studies may allow better monitoring and management of TA.

Technical details of thoracic endovascular aortic repair with fenestrations for thoracic aortic pathologies involving the aortic arch: A Chinese expert consensus.

Thoracic aortic pathologies involving the aortic arch are a great challenge for vascular surgeons. Maintaining the patency of supra-aortic branches while excluding the aortic lesion remains difficult. Thoracic EndoVascular Aortic Repair (TEVAR) with fenestrations provides a feasible and effective approach for this type of disease. The devices needed in the procedure are off-the-shelf, with promising results reported in many medical centers. Up until now, there have been no guidelines focusing exclusively on the details of the TEVAR technique with fenestrations. Experts from China have discussed the technical parts of both in situ fenestrations (needle and laser) and fenestrations in vitro (direction inversion strategy and guidewire-assisted strategy), providing a technical reference to standardize the procedure and improve its results.

Pathogenesis of giant cell arteritis with focus on cellular populations.

Giant cell arteritis (GCA), the most common non-infectious vasculitis, mainly affects elderly individuals. The disease usually affects the aorta and its main supra-aortic branches causing both general symptoms of inflammation and specific ischemic symptoms because of the limited blood flow due to arterial structural changes in the inflamed arteries. The pathogenesis of the GCA is complex and includes a dysregulated immune response that affects both the innate and the adaptive immunity. During the last two decades several studies have investigated interactions among antigen-presenting cells and lymphocytes, which contribute to the formation of the inflammatory infiltrate in the affected arteries. Toll-like receptor signaling and interactions through the VEGF-Notch-Jagged1 pathway are emerging as crucial events of the aberrant inflammatory response, facilitating among others the migration of inflammatory cells to the inflamed arteries and their interactions with the local stromal milieu. The increased use of checkpoint inhibitors in cancer immunotherapy and their immune-related adverse events has fed interest in the role of checkpoint dysfunction in GCA, and recent studies suggest a dysregulated check point system which is unable to suppress the inflammation in the previously immune-privileged arteries, leading to vasculitis. The role of B-cells is currently reevaluated because of new reports of considerable numbers of plasma cells in inflamed arteries as well as the formation of artery tertiary lymphoid organs. There is emerging evidence on previously less studied cell populations, such as the neutrophils, CD8+ T-cells, T regulatory cells and tissue residing memory cells as well as for stromal cells which were previously considered as innocent bystanders. The aim of this review is to summarize the evidence in the literature regarding the cell populations involved in the pathogenesis of GCA and especially in the context of an aged, immune system.

Endovascular Management of Aortic Arch Diseases: Current Status and Future Trends

Treatment of aortic arch (AA) diseases is challenging for surgeons. Conventional open surgery remains the “gold standard” but is associated with significant morbidity and mortality despite improvements in techniques. In the last 2 decades, thoracic endovascular aortic repair (TEVAR) has become the first-line treatment for diseases of the descending aorta, and its indications have expanded gradually. Various strategies have been proposed to preserve supra-aortic branches in TEVAR: hybrid technique, chimney technique, fenestration technique (including custom-made fenestrated or “scalloped” stent grafts, in situ fenestration, and physician-modified fenestration), and branched stent grafts. Though acceptable outcomes of endovascular aortic repair have been documented, the evidence regarding its long-term safety and efficacy is lacking, and concerns remain about the risk of cerebrovascular events, retrograde type-A dissection, endoleaks, and branch occlusion. This review discusses the current status and progress of endovascular repair of the AA, and looks toward future trends. We believe that multidisciplinary collaboration of a “HENDO” team (professionals in hybrid repair, endovascular repair, open surgery, cardiovascular anesthesia, and genetics) is essential for future repair of the AA to provide the optimal treatment.

Changes in the Relative Displacement between the Supra-Aortic Branches with Age

This study aimed to determine the normal ranges for the height and deflection angle of the aortic arch and the displacement distances between the supra-aortic branches in relation to age, sex, body mass index (BMI), and body surface area (BSA) in adults without aortic disease using non-contrast chest computed tomography (CT). The CT scans of 700 patients were analyzed. We measured the height and deflection angle of the aortic arch based on the lower level of the pulmonary artery bifurcation. The displacement distances between the supra-aortic branches in the coronal and sagittal planes were measured, and the deflection angles between these branches were calculated. Multiple linear regression analysis was used to investigate the associations of age, sex, BMI, and BSA with these aortic arch parameters. The height of the aortic arch was significantly higher (74±15mm vs. 65±12mm, P<0.001) and the left-posterior displacement distance of the left subclavian artery (LSA) to the innominate artery (IA) was greater in men than that in women. The height and deflection angle of the aortic arch increased with age. The distance by which the LSA was shifted to the left posterior of the left common carotid artery and to the left of the IA increased with age. The normal aging process is accompanied by morphological changes in the aortic arch and relative displacement between the supra-aortic branches. Identifying these parameters could lead to a comprehensive understanding of the anatomy and morphology of the aortic arch.

Endovascular surgery for thoracic aortic pathologies involving the aortic arch.

BackgroundAortic arch pathologies are serious clinical conditions associated with a very dismal prognosis. Traditional open surgery has a high mortality and is not suitable for critically ill patients. Recently years, endovascular treatment of thoracic aorta has made rapid progress and has been gradually applied to the treatment of aortic arch pathologies. However, maintaining cerebral blood flow during endovascular treatment of aortic arch lesions remains a challenge at this time. This study aims to evaluate the feasibility, efficacy, and safety of endovascular treatment of thoracic aortic pathologies involving the aortic arch, and to present initial experience with this technique.MethodsFrom October 2016 to December 2020, patients who met the inclusion criteria were enrolled. All patients underwent thoracic endovascular aortic repair with the proximal landing zone of the stent-graft in the aortic arch at Ishimaru zones 0–1, in which cerebral flow needs to be maintained during surgery, and the supra-aortic branches were reconstruction with either in situ fenestration or the chimney technique.ResultsA total of 62 cases with lesions involving the arch were treated with endovascular surgery. Total supra-aortic branches reconstruction was successfully performed in 51 cases, the left carotid artery (LCA) and the innominate artery reconstruction were performed in eight cases, the left subclavian artery (LSA) and the LCA were reconstructed in three patients. Among them, the in situ fenestration or chimney repair technique for the LSA was successful performed in 42 and 12 cases. However, in 20 patients, attempts to reconstruction the LSA using the fenestration technique were unsuccessful due to tortuous and angulated vessels. Early mortality was 6.45%. No neurological complications related to surgery occurred. Computer tomography images at post-operative follow-up (mean 3.51 months) confirmed patency of all branch stents without any signs of endoleaks, migration, conversion to retrograde dissection or receive open-heart surgery.ConclusionThe endovascular technique is an effective, feasible, safe and repeatable method to reconstruct the aortic arch, which allows for the reconstruction of the supra-aortic branches.

Scimitar Syndrome in a Newborn

Introduction: Scimitar syndrome is a rare congenital condition that is usually presented in two major types, the infantile type as a severe condition with a poor outcome (median age: 2 months) and the adult type with a better condition and good outcome. It also has a wide spectrum of clinical presentations, from being asymptomatic in the adult type to cardiac and respiratory failure and pulmonary hypertension in the infantile type. Case Presentation: In this case report, we present a 43-day-old female case referred to Taleghani Children Hospital, Gorgan, Iran, with respiratory symptoms. In a physical examination, the case had a grade II/VI murmur, dextrocardia, and respiratory distress. In evaluations, the patient had severe stenosis proximal to the left common carotid artery after its origin. The heart and mediastinum were displaced to the right side, and the thoracic aorta was normal in size and orientation. bovine type of supra-aortic arch branches in the left-sided aortic arch, hypoplasia of the right upper lobe with severe hypoplasia of the right lower lobe were seen as well. There was sequestration adjacent to the right lower lobe with a dual feeder artery directly from the abdominal aorta and celiac branch and dual draining veins. Partial anomalous pulmonary venous connection was detected in the neck, and mediastinal computed tomography (CT) angiography with reconstructed views.. Bronchoscopy revealed right main bronchus hypoplasia and right lower lobe hypoplasia. Then, with the help of angiography, scimitar syndrome diagnosis was confirmed for the patient. Conclusions: Although scimitar syndrome is an uncommon condition, it has serious complications and poor outcomes in some patients. It is necessary to be aware of this rare congenital condition and use helpful methods, such as CT angiography and angiography, to confirm the diagnosis.

A novel modular inner aortic arch stent-graft for localized Stanford type A aortic dissection aneurysm with short healthy proximal ascending aorta

Central MessageA novel modular inner aortic arch stent-graft system simplified our procedure and provided a novel therapeutic strategy for ascending and aortic arch lesions with short healthy ascending aorta. A novel modular inner aortic arch stent-graft system simplified our procedure and provided a novel therapeutic strategy for ascending and aortic arch lesions with short healthy ascending aorta. A 53-year-old man was admitted with chronic localized Stanford type A aortic dissection aneurysm (maximum diameter of 60.2 mm) with a 3-year history of hypertension and cerebral infarction. Preoperative computed tomography angiography showed the primary entry tear originated in the ascending aorta (Figure 1, A). The lengths of total ascending aorta and the proximal healthy ascending aorta were 92.1 mm and 24.0 mm, respectively. The diameter of proximal landing zone is 40.0 mm. The orifice diameters of the innominate artery (IA), left common carotid artery (LCCA), and left subclavian artery (LSA) were 14.0 mm, 7.7 mm, and 13.2 mm, respectively. Given the high risk of rupture and cerebral infarction, and the patient's refusal of transfusion for personal beliefs, we performed endovascular repair using a novel modular aortic arch stent-graft system (WeFlow-Arch; Hangzhou Endonom Medtech Co., Ltd.) (Figure 1, E and F). Since the diameter of LCCA was significantly smaller than LSA, IA and LSA were used for revascularization of supra-aortic arteries after LCCA-LSA bypass. Puncture access included: (1) left brachial artery for bridging LSA with one inner branch, (2) right common carotid artery for bridging innominate artery with another inner branch, (3) right femoral artery for implanting the main stent-grafts, and (4) left femoral vein for rapid pacing. A low transverse cervical incision was performed to expose common carotid arteries of both sides and LSA. A bypass between LCCA and LSA was performed and the proximal segment of the LCCA was planned to ligate. The endovascular procedural process is shown in Video 1. The first module, ascending aorta stent-graft (44 × 44 mm in diameter, 50 mm in length, 12 mm in diameter of inner branch), in the precurved delivery system, via femoral artery access was deployed into the ascending aorta under rapid pacing of a preset temporary pacemaker (Figure 1, C). The second modules, bridging covered stents, were deployed for bridging the supra-aortic branches and the 2 inner branches, including one 13-mm × 16-mm × 100-mm covered stent for bridging IA and two 13-mm × 13-mm × 80-mm covered stents for bridging LSA. The third module, aortic arch stent-graft (44 mm × 32 mm in diameter, 200 mm in length), was overlapped with the lumen of the first module via steerable delivery system to avoid iatrogenic migration of the first module (Figure 1, D). Segmental deployment simplified the procedures associated with complicated anatomic matching and avoided the long-time interruption of the supra-aortic blood supply. The patient was free from postprocedural symptomatic cerebral infarction. 12-month follow-up computed tomography angiography confirmed patency of the stent-graft branches, no endoleak or retrograde dissection, and complete thrombosis of false lumen with a maximum aneurysm diameter of 60.0 mm (Figure 1, B). This case indicated that this modular endograft simplified aortic arch repair procedure and provided a novel therapeutic strategy for ascending and aortic arch lesions with short healthy ascending aorta. This case was part of a clinical trial (NCT04764370), namely Guo's Aortic Arch Reconstruction: The First in Man Study of WeFlow-Arch Modular Embedded Branch Stent Graft System. This study was reviewed and approved by Chinese PLA General Hospital Medical Ethics Committee (approval number: S2018-230-01, approval date: February 28, 2019) and informed consent was taken from the patient. https://www.jtcvstechniques.org/cms/asset/59e4aa36-84b1-4a38-86a6-e0f080c88901/mmc1.mp4Loading ... Download .mp4 (27.07 MB) Help with .mp4 files Video 1Endovascular procedure. LCCA, Left common carotid artery; LSA, left subclavian artery; IA, innominate artery; RCCA, right common carotid artery; RAO, right anterior oblique; CAU, caudal oblique. Video available at: https://www.jtcvs.org/article/S2666-2507(22)00347-9/fulltext. Download .jpg (.09 MB) Help with files Video 1Endovascular procedure. LCCA, Left common carotid artery; LSA, left subclavian artery; IA, innominate artery; RCCA, right common carotid artery; RAO, right anterior oblique; CAU, caudal oblique. Video available at: https://www.jtcvs.org/article/S2666-2507(22)00347-9/fulltext.

A mathematical model for biomechanical behavior of the aortic arch.

The aortic arch plays a significant role in homeostatic mechanisms to retain blood pressure at stable balance in the cardiovascular system. Therefore, the objective is to estimate and identify cardiovascular illness imposed by the abnormal blood hemodynamic domain. In this regard, hemodynamic forces are monitored by the baroreflex of the artery wall. Therefore, these receptors quickly detect the abnormal stress magnitudes in the aortic arterial wall. The present study presents a 3D aortic arch model extracted by a Computerized tomography scan. Also, the numerical solution was carried out by ANSYS 2020 R1 in view of Fluid-Structure Interaction After that, we found wall shear stress (WSS), pressure, and velocity in the fluid domain. Also, the normal stress was analyzed to determine the aortic arch baroreflex location in the solid range. In this regard, higher WSS values are measured at the supra-aortic branches going out the aortic arch that reached 42.5 Pa. Also, higher normal stress happened at the aortic root and the supra-aortic branches and reached approximately 200 kPa at peak systole.

Theoretical Feasibility of Using Arch Branched Endograft Devices for Repair of Post Type A Aortic Dissection in Patients With Prior Ascending Aortic Replacement

Purpose: Ascending aortic replacement is a common emergency procedure for treating acute type A aortic dissection. Secondary open or endovascular interventions for residual arch pathologies is difficult because of adhesions, short prosthetic grafts, and distorted anatomies. Aortic arch branched stent grafts have emerged as a potential solution for these patients if they have suitable anatomical conditions. This study aimed to evaluate the theoretical anatomical and technical feasibility of 2 currently used aortic arch branch endografts in patients who had prior replacement of the ascending aorta. Materials and Methods: All patients who had a prosthetic ascending aortic or hemiarch replacement for acute type A dissection in a single institution between January 2013 and December 2018 were included. Contrast computed tomography images on the most recent follow-up were analyzed on a 3-dimensional workstation. Morphological parameters were measured individually for the ascending aorta, aortic arch, supra-aortic branches, and access iliac arteries. The computed tomography scan of each patient was individually evaluated for anatomical suitability for the arch branched and double-branch devices according to set selection criteria. Results: Computed tomography images of 56 patients (median age of 57 years, 45 males) were reviewed. Based on our evaluation, 26 patients (46.4%) were good candidates for an endovascular arch branched device. It would be feasible for 13 patients (23.2%), but prudent preoperative planning was required due to complicated anatomy. The other 17 patients (30.4%) were unsuitable because they met at least 1 exclusion criterion. Short prosthetic grafts, extreme graft angulations, and extensive dissections in the supra-aortic branches were the main reasons for exclusion. Conclusion: Endovascular repair using arch branched endografts is feasible in patients with prior ascending aortic arch or hemiarch replacement for acute type A aortic dissection. The most common anatomical conditions that may influence the feasibility of the arch branched endograft procedure include insufficient proximal seal length, severe angulation of the graft, and extensive aortic dissection within the supra-aortic vessels.

Minireview: Transaortic Transcatheter Aortic Valve Implantation: Is There Still an Indication?

Transaortic (TAo) transcatheter aortic valve implantation has become a valid alternative access route in patients with unsuitable femoral arteries. The current literature does not allow to clearly favor one of the alternative access routes. Every approach has its specific advantages. Transaortic (TAo) access is of particular importance in the case of calcifications of the supra-aortic branches and the aortic arch, as under these circumstances other alternative access routes, such as transaxillary or transcarotid, are not feasible. The purpose of this minireview is to give an overview and update on TAo transcatheter aortic valve implantation focusing on indication, technical aspects, and recent clinical data.

Haemodynamic Analysis of Branched Endografts for Complex Aortic Arch Repair.

This study aims to investigate the haemodynamic response induced by implantation of a double-branched endograft used in thoracic endovascular aortic repair (TEVAR) of the aortic arch. Anatomically realistic models were reconstructed from CT images obtained from patients who underwent TEVAR using the RelayPlus double-branched endograft implanted in the aortic arch. Two cases (Patient 1, Patient 2) were included here, both patients presented with type A aortic dissection before TEVAR. To examine the influence of inner tunnel branch diameters on localised flow patterns, three tunnel branch diameters were tested using the geometric model reconstructed for Patient 1. Pulsatile blood flow through the models was simulated by numerically solving the Navier–Stokes equations along with a transitional flow model. The physiological boundary conditions were imposed at the model inlet and outlets, while the wall was assumed to be rigid. Our simulation results showed that the double-branched endograft allowed for the sufficient perfusion of blood to the supra-aortic branches and restored flow patterns expected in normal aortas. The diameter of tunnel branches in the device plays a crucial role in the development of flow downstream of the branches and thus must be selected carefully based on the overall geometry of the vessel. Given the importance of wall shear stress in vascular remodelling and thrombus formation, longitudinal studies should be performed in the future in order to elucidate the role of tunnel branch diameters in long-term patency of the supra-aortic branches following TEVAR with the double-branched endograft.

Hemodynamic effects of stent-graft introducer sheath during thoracic endovascular aortic repair.

Thoracic endovascular aortic repair (TEVAR) has become the standard treatment of a variety of aortic pathologies. The objective of this study is to evaluate the hemodynamic effects of stent-graft introducer sheath during TEVAR. Three idealized representative diseased aortas were designed: aortic aneurysm, coarctation of the aorta, and aortic dissection. Computational fluid dynamics studies were performed in the above idealized aortic geometries. An introducer sheath routinely used in the clinic was virtually placed into diseased aortas. Comparative analysis was carried out to evaluate the hemodynamic effects of the introducer sheath. Results show that the blood flow to the supra-aortic branches would increase above 9% due to the obstruction of the introducer sheath. The region exposed to high endothelial cell activation potential (ECAP) expands in the scenarios of coarctation of the aorta and aortic dissection, which indicates that the probability of thrombus formation may increase during TEVAR. The pressure magnitude in peak systole shows an obvious rise, and a similar phenomenon is not observed in early diastole. The blood viscosity in the aortic arch and descending aorta is remarkably altered by the introducer sheath. The uneven viscosity distribution confirms the necessity of using non-Newtonian models, and high-viscosity region with high ECAP further promotes thrombosis. Our results highlight the hemodynamic effects of stent-graft introducer sheath during TEVAR, which may associate with perioperative complications.

Tumor mass in the lung with superior vena cava syndrome

Group of symptoms due to vena cava superior obstruction is named superior vena cava syndrome. A 65-year-old female, long-standing smoker was presented with a two-week history of dry cough and facial swelling. The patient noticed a palpable mass on the right side of the neck. Computer tomography scan with contrast showed extensive, irregular, non-homogenous consolidation in the right upper lobe, involving the right hilus, surrounding the aortic arch, supra aortic branches and pleural effusion at the right side of the body. Also, ultrasound examination of supra clavicular space showed enlarged pathologic hypoehogenic lymph node without an echogenic hilum. Ultrasound guided fine needle biopsy of lymph node was performed, and cytopathology findings showed metastatic lesion from primary microcellular lung cancer, IIIC stadium, cT4N3M0. Venous angioplasty was performed showing stenosis in the superior vena cava. After balloon dilatation, the stent was placed at the site of stenosis. The patient received chemio- and radiotherapy and survival time was seven months. Superior vena cava syndrome is an urgent clinical condition, and lung cancer is the leading cause of this syndrome. Computer tomography imaging findings and endovascular stent placement are important for detection and management of the superior vena cava thrombosis.