Hostile Hemodynamics in Distal Stent Graft-Induced New Entry Prior to Aortic Rupture: A Comparison of Transient versus Steady-State CFD Simulations.

BACKGROUND: Computational fluid dynamics (CFD) simulations model blood flow in aortic pathologies. The aim of our study was to understand the local hemodynamic environment at the site of rupture in distal stent graft-induced new entry (dSINE) after frozen elephant trunk with a clinically time efficient steady-flow simulation versus transient simulations. METHODS: Steady-state simulations were performed for dSINE, prior and after its development and prior to aortic rupture. To account for potential turbulences due geometric changes at the dSINE location, Reynolds-averaged Navier-Stokes equations with the realizable k-ε model for turbulences were applied. Transient simulations were performed for comparison. Hemodynamic parameters were assessed at various locations of the aorta. RESULTS: Post-dSINE, jet-like flow due to luminal narrowing was observed which increased prior to rupture and resulted in focal neighbored regions of high and low wall shear stress (WSS). Prior to rupture, aortic diameter at the rupture site increased lowering WSS at the entire aortic circumference. Concurrently, WSS and turbulence increased locally above the entry tear at the inner aortic curvature. Turbulent kinetic energy and WSS elevation in the downstream aorta demonstrated enhanced stress on the native aorta. Results of steady-state simulations were in good qualitative agreement with transient simulations. CONCLUSION: Steady-flow CFD simulations feasible at clinical time scales prior to aortic rupture reveal a hostile hemodynamic environment at the dSINE rupture site in agreement with lengthy transient simulations. Consequently, our developed approach may be of value in treatment planning where a fast assessment of the local hemodynamic environment is essential.

Early and midterm results of frozen elephant trunk operation with Evita open stent-graft in patients with Marfan syndrome: results of a multicentre study.

BACKGROUND: Endovascular treatment of patients with Marfan syndrome (MFS) is not recommended. Hybrid procedures such as frozen elephant trunk (FET), which combines stent-graft deployment with an integrated non-stented fabric graft for proximal grafting and suturing, have not been previously evaluated. The aim of this study was to assess the safety and feasibility of FET operation in patients with MFS. METHODS: Patients enrolled in the International E-vita Open Registry (IEOR) who underwent FET procedure between January 2001 and February 2020 meeting Ghent criteria for MFS were included in the study. Early and midterm results were retrospectively analyzed. Preoperative, postoperative and follow-up computed tomography angiography scans were analysed. RESULTS: We analyzed 37 patients [mean age 38 ± 11 years, 65% men]. Acute or chronic aortic dissection was present in 35 (95%) patients (14 and 21 patients respectively). Two (5%) patients had an aneurysm without dissection. Malperfusion syndrome was present in 4 patients. Twenty-nine (78%) patients had history of aortic surgical interventions. The 30-day and in-hospital mortality amounted to 8 and 14% respectively. False lumen exclusion was present in 73% in stented segment in last postoperative CT. The overall 5-year survival was 71% and freedom from reintervention downstream was 58% at 5 years. Of the nine patients who required reintervention for distal aortic disease, one patient died. CONCLUSIONS: FET operation for patients with MFS can be performed with acceptable mortality and morbidity. In long-term follow-up no reinterventions on the aortic arch were required. FET allows for easier second stage operations providing platform for surgical and endovascular reinterventions.

E-Vita OPEN NEO Hybrid Stent Graft: A New Frontier for Total Arch Replacement.

BACKGROUND: The ever-changing landscape of aortic arch surgery necessitates a constant update on the available devices and technologies for the contemporary management of complex aortic diseases. The E-Vita OPEN NEO hybrid stent graft system offers a unique approach for aortic arch replacement with the frozen elephant trunk technique. In contrast to its predecessors and other commercially available devices, it fits to each individual patient's needs by allowing for more proximal graft anastomosis. We sought to present our initial experience with the novel E-Vita OPEN NEO hybrid stent graft system focusing on its description, optimal graft selection, operative technique, and results in a clinical setting. METHODS: We prospectively collected data on all patients in whom the E-Vita OPEN NEO device was used between October 2020 and May 2021. The primary outcome was perioperative or with 30-day mortality. Secondary outcomes were the incidence of neurologic complications (stroke and spinal cord ischemia) and endoleak on a postoperative computed tomography angiography. RESULTS: During the study period, six patients received the novel hybrid stent device. The mean patient age was 59.3 ± 13.3 years and 83% were male. Two patients were operated on an emergent setting due to acute Stanford type A aortic dissection and there were two reoperations in patients with a history of previous repaired type A dissection. There was no perioperative or 30-day mortality and none of the patients exhibited adverse neurologic events. Two patients required completion thoracic endovascular repair due to type Ib endoleak. One patient died after a prolonged stay in the intensive care unit due to pneumonia and multiorgan failure. CONCLUSIONS: This novel device adapts to each patient's characteristics and offers a curative option for acute and chronic aortic arch and descending aortic conditions such as aneurysmal disease and aortic dissection. In addition, it offers an excellent landing station for potential endovascular therapies and allows for complete aortic remodeling.

Distal Stent Graft Induced New Entry: Risk Factors in Acute and Chronic Type B Aortic Dissections.

OBJECTIVES: Distal stent graft induced new entry (dSINE) is a rare complication associated with acute and chronic dissections after thoracic endovascular aortic repair (TEVAR) and is linked to a high re-intervention rate. The potential predicting risk factors for dSINE and long term outcome of patients after re-intervention were analysed. METHODS: This single centre, retrospective study included patients undergoing TEVAR. Multivariable analysis was used to test important interventional parameters such as distal oversizing (dOS), taper ratio (TR), angle between distal stent graft and aorta, acute dissection and stent graft length. Re-intervention characteristics were analysed and further long term follow up after re-intervention were evaluated. RESULTS: One hundred and eighty-five patients were analysed with acute (n = 77) and chronic (n = 108) dissections after TEVAR with an average follow up of 68.9 ± 32.5 months. During follow up, 12 (6.5%) patients developed dSINE after a median of 22.2 ± 20.7 months. Acute dissection was identified as a major predicting factor for dSINE development (15.8 fold increased odds), followed by increased dOS and TR. The re-intervention rate was higher in the dSINE group (83% vs. 20%, p = .001), but results indicated that no further re-intervention was needed and no new endoleak development occurred up to a mean follow up of 60.7 ± 54.8 months. No dSINE was seen in association with tapered stent grafts. CONCLUSIONS: Acute aortic dissection was found to be the major predicting factor for dSINE development, followed by increased dOS and TR. The use of tapered stent grafts might be beneficial for patients with high expected dOS and TR. In the rare case of dSINE occurrence, even when re-intervention is required, the long term prognosis is good.

Impact of Acute Intestinal Ischemia and Reperfusion Injury on Hemodynamics and Remote Organs in a Rat Model.

BACKGROUND: Acute mesenteric ischemia following cardiovascular surgery is a rare but fatal complication. We established a new rat model for hemodynamic monitoring during mesenteric ischemia/reperfusion (I/R) and evaluated the impact of mesenteric I/R on hemodynamics and remote organ injury. METHODS: Mesenteric I/R was induced in male Wistar rats by superior mesenteric artery occlusion for 90 minutes, followed by 120 minutes of reperfusion. Before I/R, ventilation and hemodynamic monitoring including mean arterial blood pressure (MAP) and cardiac output (CO) were established. During reperfusion Geloplasma (I/R + Geloplasma, N = 6) and Ringer's solution (I/R + Ringer, N = 6) were titrated according to CO and compared with I/R without volume resuscitation (I/R only, N = 6) and a sham group (sham, N = 6). Blood samples were regularly taken for serum marker measurements. After reperfusion organs were harvested for histology studies. RESULTS: After acute mesenteric I/R, MAP and CO decreased (p < 0.01) while systemic and pulmonary vascular resistance increased (p < 0.01) continuously in the I/R group. Volume substitution according to CO initially stabilized hemodynamic parameters, but CO declined independently in the late stage. Compared with the I/R + Ringer group, the I/R + Geloplasma group required less volume for resuscitation (p < 0.01), experienced less metabolic acidosis. I/R groups had more organ injuries, more neutrophils sequestration, and higher creatine phosphokinase-MB levels than sham group. CONCLUSION: A new model for CO monitoring after mesenteric I/R injury demonstrated severe hypovolemic shock during reperfusion followed by remote myocardial and lung injury. Far less colloid volume is needed for hemodynamic stabilization after I/R compared with crystalloid volume.

Role of regional aortic wall properties in the pathogenesis of thoracic aortic dissection.

OBJECTIVES: The mechanisms of the location and extension of acute aortic dissection (AD) are only poorly understood. The aim of this study was to compare the cohesion of the non-coronary aortic sinus (NAS) and the ascending aortic wall (AA) using the Dissectometer - a new device for analyses of the mechanical properties of the aorta. DESIGN: The properties of the aortic wall were analyzed with the "Dissectometer" (parameters P7, P8 and P9) in adult patients undergoing aortic root (AR) replacement in two different segments: NAS and AA. The aortic wall thickness (AWT) was measured with a micrometer. RESULTS: Thirty-three adult patients (mean age 65 ± 14 years, 80% male) were included in this study. The aortic wall of the NAS was significantly thinner than that of the AA (1.9 ± 0.4 vs. 2.3 ± 0.4, p < 0.01). In contrast, mechanical stability assessed by cohesion testing was diminished in AA samples compared to NAS samples (P7: 86.0 ± 55.0 vs. 152.3 ± 89.2, p < 0.01; P8: 2.5 ± 1.3 vs. 6.0 ± 3.1, p < 0.01; P9: 3.6 ± 1.4 vs. 7.8 ± 3.2, p < 0.01). CONCLUSIONS: This study shows that the wall of the AR is characterized by a thin but stable wall, whereas AA was found to be weaker despite its greater thickness. This difference might be involved in the development and spreading of aortic dissections.

Thoracic Endovascular Repair of Complicated Penetrating Aortic Ulcer: An 11-Year Single-Center Experience.

PURPOSE: To analyze an 11-year single-center experience of treating complicated penetrating aortic ulcer (PAU) using thoracic endovascular aortic repair (TEVAR). METHODS: This study included 63 consecutive patients (mean age 69.1±11.5 years; 40 men) with complicated PAU (42 symptomatic, 22 with rupture) who underwent TEVAR between 2002 and 2013. The PAUs were located in the aortic arch (n=11), the descending thoracic aorta (n=43), and the thoracoabdominal aorta (n=9). RESULTS: TEVAR was performed within 14 days of diagnosis in 33 (52.3%) cases (19 ruptures treated immediately); the other 30 (47.6%) patients had an average interval between diagnosis and intervention of 40±39 days. Technical success was 98.4% (62/63). One patient had a type I endoleak after stent-graft repair of a PAU in the aortic arch without great vessel transposition; another procedure was required for carotid-subclavian bypass and proximal stent-graft extension. No patient experienced spinal cord ischemia after TEVAR. Five (7.9%) patients died in-hospital; 3 had severe cardiac complications, 1 died from complications of aortic rupture, and the other succumbed to septic shock. Mean follow-up was 45.6±47.2 months, during which 12 (19.0%) patients needed a secondary intervention because of late endoleaks (n=4, 6.3%) or new complications due to disease progression. Multivariate analysis indicated that a PAU depth >15 mm was an independent predictor of mortality (hazard ratio 6.92, p=0.03). In the biomarker analysis, symptomatic patients had significantly higher D-dimer and troponin levels compared to asymptomatic patients [559.5±460.7 vs 283.2±85.2 µg/L (p=0.016) and 0.22±0.61 vs 0.02±0.03 ng/mL (p=0.04), respectively]. CONCLUSION: Patients with PAU suffer from underlying severe atherosclerotic disease and have a significant number of cardiovascular comorbidities that lead to relevant mortality and morbidity after TEVAR. As a PAU diameter >15 mm represented high risk for disease progression, these patients may be candidates for early intervention. D-dimer levels may help identify patients at risk and with progression of PAU.

Thoracic aortic aneurysm expansion due to late distal stent graft-induced new entry.

OBJECTIVES: This study analyzed the mechanism and risk factors of thoracic aortic aneurysm expansion due to late distal stent graft-induced new entry (dSINE). BACKGROUND: This late complication of thoracic endovascular aneurysm repair (TEVAR) for aortic dissection is under-recognized but potentially life-threatening. METHODS: In 142 patients who underwent TEVAR with endovascular entry sealing for acute and chronic aortic type B dissection, using commercially available straight (nontapered) stent-grafts, we examined the oversizing rate, the aortic taper ratio, and the need for reintervention. RESULTS: Nine of 142 patients developed thoracic aortic aneurysm expansion due to dSINE after TEVAR. The median follow-up was 47.5 ± 37.4 months. There was a significant difference in the distal stent-aorta angle between the patients with and without dSINE (149.08 ± 15.09° vs. 166.72 ± 12.47°, P < 0.005). Patients with dSINE showed a significantly higher taper ratio of the true lumen of the aorta (40.9 ± 14.13% vs. 25.36 ± 20.2%, P < 0.05). There was also a significant difference in the oversizing of the stent-graft in the distal landing zone (95.88 ± 49.3% vs. 55.94 ± 36.23%, P < 0.01). All patients with dSINE underwent a secondary endograft procedure without any complications or deaths. In 7 cases we used a custom-made, highly tapered stent-graft. CONCLUSIONS: Lifelong follow-up of patients is mandatory after TEVAR. A stent-graft with a tapered design should be used in aortic dissection to avoid oversizing and devastating late complications.

Left subclavian artery rerouting and selective perfusion management in frozen elephant trunk surgery.

INTRODUCTION: The frozen elephant trunk (FET) technique enables combined aortic arch and descending aortic repair. We report our experience with a modified arch replacement technique by rerouting of the left subclavian artery (LSA) and fixation of the FET in Zone 2 or proximally under selective perfusion of all three arch arteries and the downstream aorta. MATERIAL AND METHODS: From January 2005 to December 2014, 78 of 173 patients operated with the FET technique underwent rerouting of the LSA. Rerouting was performed as aortic-subclavian, aorto-axillary or carotid-subclavia bypass. Hypothermic selective antegrade cerebral perfusion was established for cerebral protection. A separate cardiopulmonary bypass circuit was added for selective LSA and downstream aorta perfusion during the arch repair. RESULTS: In-hospital mortality, stroke and paraplegia rates were 10%, 8% and 2.5%, respectively. LSA rerouting enabled total arch repair in <60 minutes of selective cerebral perfusion (mean 56 ± 15). No recurrent nerve palsy occurred. The selective perfusion of the downstream aorta led to the reduction of the distal hypothermic circulatory arrest time close to 30 minutes (p < 0.0001). DISCUSSION: LSA rerouting facilitates arch aortic repair by FET surgery. The selective perfusion of all arch arteries and the downstream aorta during open arch repair reduces the ischemic times and may improve organ protection.

Detection of aortic wall instability with the new dissectometer: Correlation with histological findings.

OBJECTIVES: Although risk stratification for aortic dissection or rupture based on aortic diameter is quite suboptimal, alternative methods for the assessment of the aortic wall stability are rare. We assessed the mechanical properties of the aortic wall by a new custom-made device mimicking transversal aortic wall shear stress during open heart surgery in comparison with histological examination. MATERIAL AND METHODS: One-hundred and five aortic walls were tested by the 'dissectometer' (seven different measured and two calculated values) as well as histological examination was performed. RESULTS: Histological examination classified the aortic wall as normal in 54 (51.4%) patients and pathologic in 51 (48.6%) patients. Six out of nine parameters assessed by the dissectometer showed a significant correlation to histological findings. Using ROC-analysis, the most reliable parameter (P9) showed a sensitivity of 93.3% and a specificity of 80.4% with an area under the curve of 0.89 when using a cut-off value of 3.4. In the logistic regression analysis, P9 was an independent predictor for aortic wall instability (OR 28.983, 95% CI 11.507-72.993, p < 0.0001). CONCLUSION: The dissectometer is suitable for discriminating between stable and unstable aortic walls with a good correlation to histological examination holding promise for direct and quick intraoperative identification of aortic walls at risk for dissection.

Validation of intravascular ultrasound for measurement of aortic diameters: Comparison with multi-detector computed tomography.

INTRODUCTION: Intravascular ultrasound (IVUS) provides real-time imaging of aortic pathology during aortic interventions. The objective of the present study was to validate IVUS measurements using computed tomography (CT) angiography in a sufficiently large cohort. MATERIAL AND METHODS: From October 2010 to February 2014, 57 consecutive patients with acute aortic syndrome underwent both IVUS and spiral CT for a total of 509 comparable thoracic aorta segments. Minimum, maximum, and mean diameters were determined at each measurement point. RESULTS: IVUS measurements of the thoracic aorta (aortic root, brachiocephalic trunk, left common carotid artery, left subclavian artery) ranged from 18-48.5 (mean 33.0) mm, versus 18-48.4 (mean 31.7) mm on CT, with a significant mean difference of 5.1% (p < 0.05). The correlation between methods was generally good, but IVUS tended toward larger diameters than CT in the aortic arch, especially the left subclavian artery. In 78% of measurement sites, total mean diameters were larger on IVUS measurements of the thoracic aorta than on CT measurements. CONCLUSION: IVUS is a reliable tool for measuring aortic diameter, especially in the descending part of the aorta. However, its pitfalls must be considered to prevent choosing an incorrectly sized stent graft in the acute setting of thoracic endovascular aortic repair.

Cardioprotective and prognostic effects of remote ischaemic preconditioning in patients undergoing coronary artery bypass surgery: a single-centre randomised, double-blind, controlled trial.

BACKGROUND: Remote ischaemic preconditioning has been associated with reduced risk of myocardial injury after coronary artery bypass graft (CABG) surgery. We investigated the safety and efficacy of this procedure. METHODS: Eligible patients were those scheduled to undergo elective isolated first-time CABG surgery under cold crystalloid cardioplegia and cardiopulmonary bypass at the West-German Heart Centre, Essen, Germany, between April, 2008, and October, 2012. Patients were prospectively randomised to receive remote ischaemic preconditioning (three cycles of 5 min ischaemia and 5 min reperfusion in the left upper arm after induction of anaesthesia) or no ischaemic preconditioning (control). The primary endpoint was myocardial injury, as reflected by the geometric mean area under the curve (AUC) for perioperative concentrations of cardiac troponin I (cTnI) in serum in the first 72 h after CABG. Mortality was the main safety endpoint. Analysis was done in intention-to-treat and per-protocol populations. This trial is registered with ClinicalTrials.gov, number NCT01406678. FINDINGS: 329 patients were enrolled. Baseline characteristics and perioperative data did not differ between groups. cTnI AUC was 266 ng/mL over 72 h (95% CI 237-298) in the remote ischaemic preconditioning group and 321 ng/mL (287-360) in the control group. In the intention-to-treat population, the ratio of remote ischaemic preconditioning to control for cTnI AUC was 0·83 (95% CI 0·70-0·97, p=0·022). cTnI release remained lower in the per-protocol analysis (0·79, 0·66-0·94, p=0·001). All-cause mortality was assessed over 1·54 (SD 1·22) years and was lower with remote ischaemic preconditioning than without (ratio 0·27, 95% CI 0·08-0·98, p=0·046). INTERPRETATION: Remote ischaemic preconditioning provided perioperative myocardial protection and improved the prognosis of patients undergoing elective CABG surgery. FUNDING: German Research Foundation.

Treatment of infected thoracic aortic prosthetic grafts with the in situ preservation strategy: a review of its history, surgical technique, and results.

For cardiothoracic surgeons prosthetic graft infection still represents a difficult diagnostic and treatment problem to manage. An aggressive surgical strategy involving removal and in situ replacement of all the prosthetic material combined with extensive removal of the surrounding mediastinal tissue remains technically challenging in any case. Mortality and morbidity rates following such a major and risky surgical procedure are high due to the nature of the aggressive surgical approach and multi-organ failure typically caused by sepsis. However, removal of the infected prosthetic graft in patients who had an operation to reconstruct the ascending aorta and/or the aortic arch is not always possible or necessary for selected patients according to current alternative treatment options. Rather than following the traditional surgical concept of aggressive graft replacement nowadays a more conservative surgical approach with in situ preservation and coverage of the prosthetic graft by vascular tissue flaps can result in a good outcome. In this article, we review the relevant literature on this specific topic, particularly in terms of graft-sparing surgery for infected ascending/arch prosthetic grafts with special emphasis on staged treatment and the use of omentum transposition.

E-vita OPEN NEO in the treatment of acute or chronic aortic pathologies: first interim results of the NEOS study.

OBJECTIVES: The aim of this multicentre study was to demonstrate the safety and clinical performance of E-vita OPEN NEO Stent Graft System (Artivion, Inc.) in the treatment of aneurysm or dissection, both acute and chronic, in the ascending aorta, aortic arch and descending thoracic aorta. METHODS: In this observational study of 12 centres performed in Europe and in Asia patients were enrolled between December 2020 and March 2022. All patients underwent frozen elephant trunk using E-vita OPEN NEO Stent Graft System. Primary end point was the rate of all-cause mortality at 30 days and secondary end points included further clinical and safety data are reported up to 3-6 months postoperatively. RESULTS: A total of 100 patients (66.7% male; mean age, 57.7 years) were enrolled at 12 sites. A total of 99 patients underwent surgery using the E-vita OPEN NEO for acute or subacute type A aortic dissection (n = 37), chronic type A aortic dissection (n = 33) or thoracic aortic aneurysm (n = 29), while 1 patient did not undergo surgery. Device technical success at 24 h was achieved in 97.0%. At discharge, new disabling stroke occurred in 4.4%, while new paraplegia and new paraparesis was reported in 2.2% and 2.2%, respectively. Renal failure requiring permanent (>90 days) dialysis or hemofiltration at discharge was observed in 3.3% of patients. Between discharge and the 3-6 months visit, no patients experienced new disabling stroke, new paraplegia or new paraparesis. The 30-day mortality was 5.1% and the estimated 6-month survival rate was 91.6% (standard deviation: 2.9). CONCLUSIONS: Total arch replacement with the E-vita OPEN NEO can be performed with excellent results in both the acute and chronic setting. This indicates that E-vita OPEN NEO can be used safely, including in the setting of acute type A aortic dissection.

Clinical cases referring to the 2023 EACTS/STS Guidelines for diagnosing and treating acute and chronic syndromes of the aortic organ.

Clinical cases referring to the EACTS/STS Guidelines for diagnosing and treating acute and chronic syndromes of the aortic organ aim to assist physicians in selecting the best management strategies for individual patients with a given condition. These expert opinions consider the impact on patient outcomes as well as the risk-benefit ratio of different diagnostic or therapeutic methods. These cases serve as a vital tool to aid physicians in making decisions in their daily practice. However, in essence, although these recommendations serve as a valuable resource to guide clinical practice, their application should be tailored to the needs of the individual patient. Each patient's case is unique, presenting its own set of variables and circumstances. This editorial is a tool designed to support, but not supersede, the decision-making process of physicians, based on their knowledge, expertise and understanding of their patients' individual situations. Furthermore, these clinical cases are based on the EACTS/STS Guidelines for diagnosing and treating acute and chronic syndromes of the aortic organ but should not be interpreted as legally binding documents. The legal responsibilities of healthcare professionals remain firmly grounded in applicable laws and regulations, and the guidelines and the clinical cases presented in this document do not alter these obligations.

The past, present and future of minimally invasive therapy in endovascular interventions: a review and speculative outlook.

Cardiovascular disease is a leading cause of death in all developed countries. In response to this need, endovascular management techniques have been developed across a large range of medical specialties. Minimally invasive percutaneous interventions were initially complex and challenging, but with the continued development of equipment and expertise their use has become routine in many fields. With routine use, it has become important to establish the safety and efficacy of endovascular treatments against the respective "gold standard" procedures, especially in light of their initial intended use for the management of patients at unacceptably high risk for standard therapy only. Such evaluation has to take into account the variety and diversity of devices and techniques, as well as the effects of operator dependability. Endovascular techniques are increasingly recognised as valid alternative management options for a variety of conditions, and it is anticipated that the current trend towards minimally invasive techniques will continue in the future, with moves towards increasingly complex endovascular techniques and hybrid interventions.

First insights into the role of wall shear stress in the development of a distal stent graft induced new entry through computational fluid dynamics simulations.

Background: Distal stent graft induced new entry (dSINE) is an emerging complication after frozen elephant trunk (FET) procedure. The aim of this computational fluid dynamics (CFD) study was to investigate the role of wall shear stress (WSS) after the development of dSINE based on hemodynamic changes. Methods: Aortic diameter and WSS of five patients who developed a dSINE after FET procedure were retrospectively analyzed before and after the occurrence of dSINE. Patient-specific 3-dimentional surface models of the aortic lumen were reconstructed from computed tomography angiographic datasets (pre dSINE: n=5, dSINE: n=5) to perform steady-state CFD simulations with laminar blood flow and zero pressure outlet conditions. WSS was calculated at the level of the stent graft (SG), the landing zone of the SG and at a location further distal to the SG, as well as on the outer and inner curvature of the aorta from SG center to its distal end. Results: Post dSINE occurrence, median WSS increased significantly from 0.87 [interquartile range (IQR): 0.83-1.03] to 1.55 (IQR: 1.09-2.70) Pa, (P=0.043) within the SG and from 1.22 (IQR: 0.81-1.44) to 1.76 (IQR: 1.55-3.60) Pa, (P=0.043) at the landing zone of the SG. A non-significant increase from 1.22 (IQR: 0.59-3.50) to 2.58 (IQR: 1.16-3.78) Pa, (P=0.686) further downstream was observed. WSS at the outer curvature of the SG was significantly higher compared to WSS at the inner curvature for dSINE. Conclusions: Adverse hemodynamic conditions in the form of elevated WSS consist inside and at the distal end of the SG as well as at the outer curvature of the aorta, which may contribute to weakening of the aortic wall. These new findings emphasize the relevance and potential of WSS in dSINE for additional adverse events, such as aortic rupture. Further prospective studies are warranted to explore if the combination of clinical parameters with WSS might be useful to decide which patients require an urgent reintervention in terms of a SG extension.

Treatment of right-sided aortic arch aneurysms with aberrant left subclavian artery with Kommerell's diverticulum using the frozen elephant trunk technique.

OBJECTIVES: The ideal treatment for aneuryms of aberrant left subclavian arteries with Kommerell's diverticulum arising from right aortic arches remains open. METHODS: Between January 2015 and December 2020, 5 patients with aneurysms from a right-sided aortic arch with aberrant left subclavian artery and Kommerell's diverticulum underwent repair by using the frozen elephant trunk technique in 3 aortic centres. Patients' characteristics were retrospectively reviewed and the surgical procedure and outcomes are presented. RESULTS: The median age of the 2 male and 3 female patients was 59 (range from 49 to 63) years. The median operative times were as follows: surgery 405 min (range from 335 to 534), cardiopulmonary bypass time 244 min (range from 208 to 280) and aortic clamp time 120 min (from 71 to 184). The mean core temperature was 25.94°C (from 24 to 28). The intensive care unit stay was 4 days (range from 1 to 8) and the in-hospital stay 21 days (from 16 to 34). All patients were discharged and we observed no stroke or spinal cord ischaemia postoperatively. During the median follow-up time of 1003 days (range from 450 to 2306), 3 patients required subsequent thoracic endovascular distal stent graft extension. CONCLUSIONS: The frozen elephant trunk technique is a good treatment option for patients with aneuryms of an aberrant left subclavian artery with Kommerell's diverticulum arising from right aortic arches. Secondary stent graft extension is a frequently needed component of the treatment concept.