Thoracic Endovascular Aortic Repair Procedure Research Articles

Endovascular management of aortic aneurysm with severe neck angulation and/or iliac artery tortuosity using multiple stiff wire technique: a case series.

Suitable aortic neck is one of the essential components for thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR). Advanced techniques were developed to adjust and compromise the aneurysm neck angulation but with adding additional devices and complexity to the procedure. We proposed a simple technique to modify severe neck angulation and/or iliac artery tortuosity by using the multiple stiff wire (MSW) technique. Two femoral accesses were required for the MSW technique. A guidewire with a support catheter was inserted through the right and left femoral arteries and positioned in the abdominal or thoracic aorta. Wire exchanges were done with extra stiff wire in both femoral accesses. It can be considered to add multiple stiff wires to align the torturous neck / iliac artery. Delivery of the stent graft main body can be done via one of the accesses. Six patients with different aortic pathology were admitted to our hospital. Four patients undergo EVAR procedure and two patients undergo TEVAR procedure. All patients had aortic neck angulation problems with one patient having iliac artery tortuosity. MSW technique was performed on the patients with good results. Follow-up CTA after 3 months revealed a good stent position without stent migration and no endoleak was found in all but one patient. MSW technique is a simple and effective technique to modify aortic neck/iliac artery angulation in TEVAR or EVAR procedure.

Endovascular management of aortic aneurysm with severe neck angulation and/or iliac artery tortuosity using multiple stiff wire technique: a case series

Background: Suitable aortic neck is one of the essential components for thoracic endovascular aortic repair (TEVAR) and endovascular aortic repair (EVAR). Advanced techniques were developed to adjust and compromise the aneurysm neck angulation but with adding additional devices and complexity to the procedure. We proposed a simple technique to modify severe neck angulation and/or iliac artery tortuosity by using the multiple stiff wire (MSW) technique. Method: Two femoral accesses were required for the MSW technique. A guidewire with a support catheter was inserted through the right and left femoral arteries and positioned in the abdominal or thoracic aorta. Wire exchanges were done with extra stiff wire in both femoral accesses. It can be considered to add multiple stiff wires to align the torturous neck / iliac artery. Delivery of the stent graft main body can be done via one of the accesses. Result: Six patients with different aortic pathology were admitted to our hospital. Four patients undergo EVAR procedure and two patients undergo TEVAR procedure. All patients had aortic neck angulation problems with one patient having iliac artery tortuosity. MSW technique was performed on the patients with good results. Follow-up CTA after 3 months revealed a good stent position without stent migration and no endoleak was found in all but one patient. Conclusion: MSW technique is a simple and effective technique to modify aortic neck/artery angulation in TEVAR or EVAR procedure.

Avant-Garde Endovascular Stent Graft Insertion in Dissected Ascending Thoracic Aortic Aneurysm.

Current guidelines and regulatory parameters for cardiothoracic surgery in the United States establish that open surgery is the first front line for treating ascending thoracic aortic aneurysms (ATAA). Despite advances in performing endovascular procedures in thoracic aortic aneurysms, there are no approved state-of-the-art techniques that allow endovascular procedures to be performed in ATAA. Thus, thoracic endovascular aortic repair (TEVAR) of the ascending aorta, as we will demonstrate, is a useful and effective technical opportunity for treating high-risk patients with type A dissections, intramural hematomas, and pseudoaneurysms. In this case, an 88-year-old female patient was consulted due to a preliminary diagnosed descending thoracic aortic aneurysm. As a result of uncertainty regarding the initial diagnosis, abdominal-pelvic and chest computed tomography scan tests contradicted the original conclusion and surprisingly yielded a different scenario; in fact, the patient had a dissected ATAA. Using the TEVAR procedure, the patient's ATAA was treated with a thoracic GORE TAG endograft stent (W. L. Gore & Associates, Inc., Newark, DE, USA). Four weeks later, the aneurysm was completely thrombosed, and the stent-graft was properly in place.

Outcomes of Secondary Endovascular Aortic Repair After Frozen Elephant Trunk.

The aim of this study was to evaluate the midterm outcomes of secondary extension of frozen elephant trunk (FET) by means of thoracic endovascular aortic repair (TEVAR). This single-center prospective study was conducted in a tertiary aortic center on consecutive patients having undergone TEVAR with an endograft covering most of the 10 cm FET module with 2 to 4 mm oversizing. All patients were monitored by computerized tomography angiography (CTA) at sixth month and yearly thereafter. From January 2015 to July 2022, among 159 patients who received FET, 30 patients (18.8%) underwent a TEVAR procedure (13 for a thoracoabdominal aneurysm, 11 for a chronic aortic dissection and 6 for an emergency procedure). All connections were successfully achieved with 2 postoperative deaths (6.6%) and 1 paraplegia (3.3%). At a median follow-up of 21 months (interquartile range [IQR], 4.2-34.7), 5 patients (25%) required a fenestrated-branched endovascular aortic repair (F-BEVAR) extension followed by 4 patients with 5 reinterventions, 3 for a Type 3 endoleak due to disconnection between FET and TEVAR endograft, and 2 unrelated to the FET for a secondary Type 1C endoleak. All reinterventions were successful, without mortality or morbidity. In this series, FET connection with a TEVAR endograft was effective with low postoperative morbidity but with a risk of aortic reintervention related to disconnection between the FET and TEVAR endograft. These results suggest the need for annual CTA monitoring with no time limit in patients following connection of the FET with a TEVAR endograft. In this series of 30 patients, midterm outcomes of secondary extension of frozen elephant trunk (FET) by thoracic endovascular repair (TEVAR) showed 3 disconnections (10%) with a Type 3 endoleak between FET and TEVAR. These findings suggest the need for annual CTA monitoring with no time limit. But so far, only a few studies provide some information after one year while the risk of disconnection increases over time and becomes a concern after 3 years. This is the new message brought by our study.

Comparative Analysis of Endovascular Repair of Single-Branched Stent-Graft and Hybrid Procedure for Patients With Type B Acute Aortic Dissection Involving the Left Subclavian Artery.

Thoracic endovascular aortic repair (TEVAR) with left subclavian artery (LSA) revascularization has been used in patients with type B aortic dissection (TBAD), with inadequate proximal landing zone (PLZ). The outcomes of comparisons between TEVAR and hybrid procedure on patients with TBAD, with inadequate PLZ, are rarely reported. This study sought to compare and clarify the early and midterm outcomes between TEVAR and hybrid procedure in patients with TBAD, with inadequate PLZ. Between January 2019 and December 2021, 93 patients with TBAD, with inadequate PLZ, who underwent TEVAR or hybrid procedure, were retrospectively evaluated in Beijing Anzhen hospital. Demographics, comorbidities, preoperative imaging features, periprocedural details, and follow-up outcomes were analyzed. Survival was analyzed according to Kaplan-Meier method. TEVAR procedures were performed on 41 patients (TEVAR group) and hybrid procedures on 52 patients (hybrid group). Early events, 30 day mortality, and all-cause mortality, were not significantly different between the 2 groups. However, patients receiving TEVAR had significantly shorter procedure time (p<0.001), hospital stay (p<0.001), and intensive care unit (ICU) stay (p=0.001) compared with those in the hybrid group. Patients receiving TEVAR had significantly lower midterm events (p=0.014) and re-intervention (p=0.015) compared with those in the hybrid group. The study indicated that TEVAR with LSA revascularization for TBAD with inadequate PLZ is associated with a trend toward lower rates of midterm events, while the early and midterm mortalities were comparable with those in hybrid procedure. This study is novel as it compared the outcomes between thoracic endovascular aortic repair (TEVAR) and hybrid procedure in patients with type B aortic dissection (TBAD), with inadequate proximal landing zone, which has been rarely reported previously. We believe that our study makes a significant contribution to the literature because it is clinically relevant as it demonstrated that TEVAR with left subclavian artery (LSA) revascularization for TBAD with inadequate proximal landing zone is associated with a trend toward lower rates of mid-term events, while the early and mid-term mortalities were comparable with those in the hybrid procedure.

Reintervention after Thoracic Endovascular Aortic Repair of Uncomplicated Type B Aortic Dissection

Data are scarce regarding the incidence, reasons, potential risk factors, and long-term outcomes of reintervention after thoracic endovascular aortic repair (TEVAR) in patients with uncomplicated type B aortic dissection (TBAD). Between January 2010 and December 2020, 238 patients with uncomplicated TBAD who received TEVAR were analyzed retrospectively. The clinical baseline data, aorta anatomy, dissection characteristics, and details of the TEVAR procedure were evaluated and compared. A competing-risk regression model was used to estimate the cumulative incidences of reintervention. The multivariate Cox model was used to identify the independent risk factors. The mean follow-up time was 68.6 months. A total of 27 (11.3%) cases of reintervention were observed. The competing-risk analyses showed that the 1-, 3-, and 5-year cumulative incidences of reintervention were 5.07%, 7.08%, and 14.0%, respectively. Reasons for reintervention included endoleak (25.9%), aneurysmal dilation (22.2%), retrograde type A aortic dissection (18.5%), distal stent-graft-induced new entry and false lumen expansion (18.5%), and dissection progression and/or malperfusion (14.8%). Multivariable Cox analysis demonstrated that a larger initial maximal aortic diameter (Hazard ratio [HR], 1.75; 95% Confidence interval [CI], 1.13-2.69, p = 0.011) and increased proximal landing zone oversizing (HR, 1.07; 95% CI, 1.01-1.47, p = 0.033) were the significant risk factors for reintervention. Long-term survival rates were comparable between patients with or without reintervention (p = 0.915). Reintervention after TEVAR in patients with uncomplicated TBAD is not uncommon. A larger initial maximal aortic diameter and excessive proximal landing zone oversizing are associated with the second intervention. Reintervention does not significantly affect long-term survival.

Early and midterm outcomes of thoracic endovascular aortic repair with Lifetech Ankura™ thoracic endograft: A single tertiary center experience

Aim: Thoracic aortic pathologies describe a wide spectrum of potentially life-threatening diseases almost always in a comorbid aged patient cohort. Thoracic endovascular aortic repair (TEVAR) is a less invasive treatment choice, offering reduced mortality and morbidity compared to open surgery. We decided to reveal our experience over safety and efficacy data with Lifetech Ankura™ Thoracic endografts with early and midterm outcomes, retrospectivelytiology. Material and Methods: Between January 2018 and January 2023, for a 5-year period, 203 patients who experienced TEVAR procedure with Lifetech Ankura™ Thoracic endograft were retrospectively evaluated. For the patients who required revascularization of the vessel branches originating from the aortic segments, all types of assistive techniques were performed. Intentional coverage of Left subclavian artery was also performed mostly in urgent patients. Results: 251 endografts were implanted in 203 patients. The most frequent aortic pathologies were the thoracic aortic fusiform aneurysm (56.6%) and type B aortic dissection (25.6%), respectively. Early (30-day/in-hospital) mortality occurred in 9 patients in total (4.4%). Technical success rate was 100%, and there was no conversion to open surgery. No other major adverse event, including cerebral, cardiac, or renal complication requiring dialysis, was observed. The average intensive care unit time was 16.9±11 hours (2-160), length of stay was 5.1±3.2 days. CSF drainage was performed in 51 patients inserted before the procedure prophylactically (25.1%). All patients who survived the operation were followed for 18.6±9.3 months. In the follow up period, four patients needed extension for endoleaks and two additive petticoat procedures were performed. One patient who had TEVAR due to a malperfused type B aortic dissection in the acute phase experienced RTAD 2 weeks after the initial procedure. Conclusion: TEVAR with LifeTech Ankura™ Thoracic Stent Graft system provides a safe, effective, and durable treatment with successful early outcomes and technical success. Wide spectrum in length and non-identical radiopaque proximal markers seem to facilitate some advanced endovascular skills. Long-term durability of the endograft should be tested.

Applicability assessment for in-silico patient-specific TEVAR procedures

Thoracic Endovascular Aortic Repair (TEVAR) is a minimally invasive technique to treat thoracic aorta pathologies and consists of placing a self-expandable stent-graft into the pathological region to restore the vessel lumen and recreate a more physiological condition. Exhaustive computational models, namely the finite element analysis, can be implemented to reproduce the clinical procedure. In this context, numerical models, if used for clinical applications, must be reliable and the simulation credibility should be proved to predict clinical procedure outcomes or to build in-silico clinical trials. This work aims first at applying a previously validated TEVAR methodology to a patient-specific case. Then, defining the TEVAR procedure performed on a patient population as the context of use, the overall applicability of the TEVAR modeling is assessed to demonstrate the reliability of the model itself following a step-by-step method based on the ASME V&V40 protocol. Validation evidence sources are identified for the specific context of use and adopted to demonstrate the applicability of the numerical procedure, thereby answering a question of interest that evaluates the deployed stent-graft configuration in the vessel.

Delayed aortic regurgitation after TEVAR procedure: a case report

BackgroundAcute aortic regurgitation (AR) is uncommon condition and usually results in an emergent situation because the left ventricle does not adapt quickly due to a sudden increase in end-diastolic volume caused by the regurgitant flow. Thoracic endovascular aortic repair (TEVAR) is a procedure that places a stent-graft on the lesion of thoracic aorta through a minimally invasive approach.Case presentationHere we report that a catheter-induced aortic valve injury associated with TEVAR can cause delayed AR, exemplified by the case of a patient who developed acute AR 42 months after TEVAR. For this, aortic valve replacement was performed and the patient was discharged without complications.ConclusionOur results demonstrate that when a catheter-related procedure is performed around the aortic valve, slight injury of the valve can cause aortic insufficiency even 3 years after surgery. Consequently, when performing a catheter-related procedure around the aortic valve, special attention is always required.

Aortoesophageal Fistula Induced by an Indwelling Nasogastric Tube: A Case Report

A 91-year-old woman who presented with melena and hypovolemic shock visited the emergency room. She received enteral nutrition by nasogastric tube in a bedridden state due to hip surgery. Gastroscopy initially suggested a simple ulcer that occurred after a nasogastric tube was placed for a long time, but the ulcer was deep, and the amount of instantaneous bleeding was considerable. Therefore, an aortoesophageal fistula was suspected. Angiography was performed instead of endoscopic hemostasis, followed by thoracic endovascular aortic repair (TEVAR). After the TEVAR procedure, the patient recovered without further gastrointestinal bleeding. Prompt judgment and communication between the endoscopist and the interventional physician are important for successful hemostasis in an aortoenteric fistula patient.

5-Year Follow-Up of Endovascular Management in a Patient with Chronic Concomitant DeBakey Type II and IIIa Aortic Dissection.

The incidence of chronic concomitant DeBakey Type II and IIIa aortic dissection is uncommon and complex. Since the mortality rate is very high, it requires a precise and holistic treatment plan. In some cases, when the patients refuse to undergo open surgery or the patients' condition is not suitable for open surgery, thoracic endovascular aortic repair (TEVAR) is the recommended therapeutic approach. In this case, a patient refused to undergo open surgery and chose TEVAR instead. The patient survived the procedure and lived for years. We present the case of a successful TEVAR procedure in a patient with chronic concomitant DeBakey Type II and IIIa aortic dissection in a 51-year-old man and the 5-year postoperative follow-up of the patient's condition.

Surgical Treatment of Retrograde Type A Aortic Dissection After Thoracic Endovascular Aortic Repair.

Data are scarce regarding retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR). This study aimed to investigate the clinical characteristics and surgical treatment outcomes of patients who developed RTAD after TEVAR.From January 2015 to January 2020, 25 consecutive patients (aged 52 ± 11.69 years) of RTAD after TEVAR received open surgery. All patients received total arch replacement (TAR) with the frozen elephant trunk (FET). The proximal part of the TEVAR stent was removed using a wire scissor. The distal part of the TEVAR stent in the descending aorta was preserved. Data of 50 random patients of type A aortic dissection without prior TEVAR were collected during the same period. We compared the perioperative and midterm follow-up outcomes between patients with prior TEVAR and patients without prior TEVAR.The mean cardiopulmonary bypass time, aortic cross-clamp time, and deep hypothermic circulatory arrest time were 173.7 ± 44.1, 109.5 ± 31.4, and 21.6 ± 6.8 minutes in the RTAD group, respectively. These times are similar to those of the no-RTAD group. The median interval between the initial TEVAR procedure and RTAD was 8.5 months (range, 0-72 months). New entry tears that were induced by the proximal end of the TEVAR stent were found in 23 (92%) patients of the RTAD group. There were no significant differences in major adverse events and overall survival between the two groups.TAR with the FET technique was feasible for the treatment of RTAD after TEVAR, with acceptable early and midterm results.

A Case Report of Endografting Using a Long Sheath under the Assistance of a Through-and-Thorough Wire Technique for an Extremely Tortuous Aortic Anatomy

Introduction: Despite its rapid technological development and widespread uptake for thoracic aortic disease, an extremely tortuous aortic anatomy is considered a contraindication for thoracic endovascular aortic repair procedure. We report a case of a successful thoracic endovascular aortic repair using techniques to straighten an extremely tortuous aorta friendly. Methods: A 78-year-old man with frequent surgical history of aortic repair was admitted to our outpatient clinic because of dyspnea and back pain. Enhanced computed tomography scan revealed type Ib endoleak, acute enlargement of the remnant native aorta and an extremely tortuous aorta. We successfully performed a thoracic endovascular aortic repair using a Gore DrySeal 65 cm sheath, combined with a Gore C-Tag device under the assistance of a through-and-thorough wire technique in the distal descending aorta. Conclusions: Using all the available techniques, thoracic endovascular aortic repair can be performed even in the most

Short-term results of chimney stent revascularization of left subclavian artery and Zone 2 thoracic endovascular aortic repair for patients with aortic dissection or transection

Background In this study, we present the short-term results of revascularization of left subclavian artery with the chimney technique in patients with aortic dissection or transection who underwent Zone 2 thoracic endovascular aortic repair. Methods A total of 11 patients (6 males, 5 females; mean age: 56.4±11.5 years; range, 38 to 76 years) who underwent Zone 2 thoracic endovascular aortic repair procedure and left subclavian artery revascularization with the chimney technique between April 2017 and January 2020 in our clinic were retrospectively analyzed. All patients were followed at one, three, six months and one year with computed tomography angiography. Results The mean follow-up was 19.7±14.5 (range, 6.3 to 45.8) months. Endoleak occurred in one (9%) patient and gutter leak occurred in three (27%) patients. The mean endoleak-free (including gutter leak) time was 19.9±5.4 (95% confidence interval: 9.36-30.34) months. No mortality occurred in any of the patients. No occlusion occurred in the chimney grafts. Conclusion The chimney revascularization technique is an alternative to other revascularization techniques of the left subclavian artery during thoracic endovascular aortic repair.

Radiation-Free Thoracic Endovascular Aneurysm Repair with Fiberoptic and Electromagnetic Guidance: A Phantom Study

PurposeTo evaluate the feasibility and accuracy of a radiation-free implantation of a thoracic aortic stent graft employing fiberoptic and electromagnetic tracking in an anthropomorphic phantom. Materials and MethodsAn anthropomorphic phantom was manufactured based on computed tomography (CT) angiography data from a patient. An aortic stent graft application system was equipped with a fiber Bragg gratings and 3 electromagnetic sensors. The stent graft was navigated in the phantom by 3 interventionalists using the tracking data generated by both technologies. One implantation procedure was performed. The technical success of the procedure was evaluated using digital subtraction angiography and CT angiography (before and after the intervention). Tracking accuracy was determined at various anatomical landmarks based on separately acquired fluoroscopic images. The mean/maximum errors were measured for the stent graft application system and the tip/end of the stent graft. ResultsThe procedure resulted in technical success with a mean error below 3 mm for the entire application system and <2 mm for the position of the tip of the stent graft. Navigation/implantation and handling of the device were rated sufficiently accurate and on par with comparable, routinely used stent graft application systems. ConclusionsThe study demonstrates successful stent graft implantation during a thoracic endovascular aortic repair procedure employing advanced guidance techniques and avoiding fluoroscopic imaging. This is an essential step in facilitating the implantation of stent grafts and reducing the health risks associated with ionizing radiation during endovascular procedures.

Early Result of TEVAR for Thoracic Aortic Aneurysm: An Experience in Ramathibodi Hospital

Background: Traditional treatment of patients with thoracic aortic aneurysms is open surgical graft replacement. At present, thoracic endovascular aortic repair (TEVAR) is an alternative option for treat patients who have high surgical risk. The authors retrospectively reviewed result of TEVAR in patients diagnosed with thoracic aortic aneurysm in Ramathibodi Hospital in 5 years, especially mortality, postoperative morbidity. Objective: To evaluate a results of TEVAR for thoracic aortic aneurysm and to identify post-operative complication. Material and Methods: The authors reviewed data from patients who were diagnosed with thoracic aortic aneurysm and underwent TEVAR procedure at Ramathibodi Hospital from 1 January 2014 to 31 December 2018. Baseline characteristics and post procedural imaging were collected and analyzed. Univariate analysis was used to identify risks associated with endoleak. Survival and reintervention rate were estimated using Kaplan-Meier methodology and between groups comparison was analyzed using the log rank test. Results: Total 33 patients were included in the analysis, with a mean age of 68.57 years. There were 7 patients with endo leak (21.21%). Endo leak was more common in male (6 out of 7, 85.70%). Renal failure occurred in only 1 patient from all (3.00%). Stroke and/or paraplegia was found in 1 patient (3%) and respiratory complication in 5 patients (15.10%). Two patients in non endoleak group died (6.1% of all). No incidence of graft migration and distal sine (stent induced new entry tear). Operative time was found to be associated with risk for developing endo leak (p-value=0.015, 95% CI 1.00 to 1.03). Conclusion: TEVAR procedure for thoracic aortic aneurysm in Ramathibodi Hospital has low in mortality and postoperative complications. However, longer operative time is associated with an increased risk in endoleak in TEVAR procedure. Keywords: Thoracic aneurysm; Thoracic endovascular aortic repair; TEVAR

Abstract 10478: Comprehensive Mechanical Modelling of Thoracic Endovascular Aortic Repair in Type A Aortic Dissection

Background: Thoracic endovascular aortic repair (TEVAR) in selected proximal (Stanford type A) aortic dissection (TAAD) cases has been reported, however, the limitation and criteria for TEVAR applied in TAAD remain controversial. Virtual stent-graft (SG) deployment simulation based on the finite element method is an emerging tool that allows TEVAR to be reproduced for detailed analysis of biomechanical interaction between native vessel wall and SG device. Methods: A TAAD patient underwent an unsuccessful TEVAR followed by salvage open surgical repair. Pre-TEVAR CT angiogram was used to establish the 3D geometry of the dissected aorta for later analysis. Perioperative DSA was used to measure the aortic root motion and determine SG position in the simulation model. Specimen of the harvested aortic tissue was used for histological analysis and tensile test to define isotropic hyperelastic properties of the aortic wall. Results: Aortic root motion was decomposed into a component normal to the sinotubular junction (STJ) and a component parallel to the STJ. The largest motion was 4.14 mm in normal direction and 3.5 mm in parallel direction. The continuous motion was used to define the displacement boundary condition at the aortic root in a finite element model. The histology revealed preserved both elastic fibres and collagen at the proximal landing zone. A small area of inflammatory infiltration was noted at the tunica externa which may related to the dissected lamella. Tensile testing showed that the aortic wall ruptured at the stress of 250-1250 kPa while the lamella ruptured at 80-160 kPa. Simulation precisely reproduced the SG configuration after TEVAR procedure. Maximum principal stress at 301 kPa was found on the lamella during simulation, which is significantly higher than stress tolerance of the lamella. Conclusion: Microstructure of the lamella and aortic wall components determine the capacity in resisting SG induced focal stress. During the deployment, the proximal end of SG landed directly onto the lamella where the maximum stress exceeded the tolerance of the lamella thus causing rupture and allowing the SG to penetrate into the false lumen.

Therapeutic window for obtaining favorable remodeling after thoracic endovascular aortic repair of type B aortic dissection

ObjectiveThe purpose of the present study was to determine the most appropriate timing for thoracic endovascular aortic repair (TEVAR) of type B aortic dissection (TBAD) in terms of remodeling of the aorta. MethodsA total of 41 patients who had undergone TEVAR for the treatment of aortic dissection were included in the present study. The patients were divided into two groups: those who had undergone TEVAR in the acute or subacute phase (group A) and those who had undergone TEVAR in the chronic phase (group B). The indications for TEVAR as the treatment of TBAD were the presence of aortic rupture or malperfusion of the aortic branches, a maximum aortic diameter of ≥40 mm on the initial diagnostic computed tomography scan, and/or expansion of the aorta of ≥5 mm within 3 months for acute and subacute TBAD. The indication was a maximum aortic diameter of ≥50 mm or expansion of the aorta of ≥5 mm within 1 year for chronic TBAD. The diameters of the aorta, true lumen, and false lumen were measured at the level of the most dilated part of the descending aorta (level M) and at the diaphragm (level D) on the computed tomography scan obtained before TEVAR and at the 2-year follow-up examination. ResultsThe median interval between TEVAR and the onset of TBAD was 0.2 month (interquartile range, 0.03-0.7 month) in group A (n = 21) and 32 months (interquartile range, 4.7-35.2 months) in group B (n = 20). Except for the aortic diameter at level D in group B, favorable remodeling was obtained at both levels in both groups. The diameter change ratio of the aorta at level D was significantly greater in group A than in group B (P = .02). Receiver operating characteristic curve analysis of the interval for a significant decrease in the aortic diameter at level D yielded 4.2 months as the optimal threshold for performing TEVAR (area under the curve, 0.859; 95% confidence interval, 0.7-1.0). ConclusionsTEVAR for TBAD will result in favorable outcomes, irrespective of the timing of the procedure. However, it might be more effective to perform TEVAR within 4.2 months of the onset of TBAD, provided that the TEVAR procedure can be performed safely.

Patient-specific simulation of stent-graft deployment in type B aortic dissection: model development and validation

Thoracic endovascular aortic repair (TEVAR) has been accepted as the mainstream treatment for type B aortic dissection, but post-TEVAR biomechanical-related complications are still a major drawback. Unfortunately, the stent-graft (SG) configuration after implantation and biomechanical interactions between the SG and local aorta are usually unknown prior to a TEVAR procedure. The ability to obtain such information via personalised computational simulation would greatly assist clinicians in pre-surgical planning. In this study, a virtual SG deployment simulation framework was developed for the treatment for a complicated aortic dissection case. It incorporates patient-specific anatomical information based on pre-TEVAR CT angiographic images, details of the SG design and the mechanical properties of the stent wire, graft and dissected aorta. Hyperelastic material parameters for the aortic wall were determined based on uniaxial tensile testing performed on aortic tissue samples taken from type B aortic dissection patients. Pre-stress conditions of the aortic wall and the action of blood pressure were also accounted for. The simulated post-TEVAR configuration was compared with follow-up CT scans, demonstrating good agreement with mean deviations of 5.8% in local open area and 4.6 mm in stent strut position. Deployment of the SG increased the maximum principal stress by 24.30 kPa in the narrowed true lumen but reduced the stress by 31.38 kPa in the entry tear region where there was an aneurysmal expansion. Comparisons of simulation results with different levels of model complexity suggested that pre-stress of the aortic wall and blood pressure inside the SG should be included in order to accurately predict the deformation of the deployed SG.

Penetrating aortic ulcer post migration of thoracic aortic endoprosthesis: Case report

IntroductionThoracic endovascular aortic repair (TEVAR) is the first treatment option for many thoracic aortic pathologies. Especially after aortic dissections, it is possible to have progression during follow-up with appearance of new lesions on arterial wall. Herein, we report a case of Penetrating Aortic Ulcer (PAU) post release of Thoracic endoprosthesis.Presentation of caseA 67-years-old male with hypertension and diabetes mellitus was followed at our hospital after an emergency procedure for Type B aortic dissection (TBAD) complicated by symptomatic large infrarenal AAA and treated with a proximal TEVAR plus chimney for left subclavian artery and PETTICOAT with EVAR for abdominal aortic disease. Follow up at 15 months showed a deep PAU with partial crush of stent in Left Subclavian Artery. Thus, we performed a left carotid-subclavian bypass and subsequently a TEVAR procedure with release of Bolton Relay endoprosthesis (Terumo Aortic, Sunrise, Florida, United States).DiscussionIn literature there are few studeis that focus on migration after TEVAR during follow-up. Elongation, changes of tortuosity on thoracic aorta after TEVAR, can help to determine a migration of prosthesis. In this case Bolton Relay endoprosthesis (Terumo Aortic, Sunrise, Florida, United States) has permitted to improve precision and quality of procedure.ConclusionIn literature there are few studies reporting complications of TEVAR post prosthesis migration. In this case, Bolton Relay endoprosthesis was useful and safe.