Status of branched endovascular aortic arch repair

Open, endovascular or hybrid repair of aortic arch disease: narrative review of diverse strategies with diverse options

OBJECTIVES

The management of aortic arch disease is complex. Open surgical management continues to evolve, and the introduction of endovascular repair is revolutionizing aortic arch surgery. Although these innovative techniques have generated the opportunity for better outcomes in select patients, they have also introduced confusion and uncertainty regarding best practices.

METHODS

In New York, we developed a collaborative group, the New York Aortic Consortium, as a means of cross-linking knowledge and working together to better understand and treat aortic disease. In our meeting in May 2023, regional aortic experts and invited international experts discussed the contemporary management of aortic arch disease, differences in interpretation of the available literature and the integration of endovascular technology into disease management. We summarized the current state of aortic arch surgery in this review article.

RESULTS

Approaches to aortic arch repair have evolved substantially, whether it be methods to reduce cerebral ischaemia, improve haemostasis, simplify future operations or expand options for high-risk patients with endovascular approaches. However, the transverse aortic arch remains challenging to repair. Among our collaborative group of cardiac/aortic surgeons, we discovered a wide disparity in our practice patterns and our management strategies of patients with aortic arch disease.

CONCLUSIONS

It is important to build unique institutional expertise in the context of complex and evolving management of aortic arch disease with open surgery, endovascular repair and hybrid approaches, tailored to the risk profiles and anatomical specifics of individual patients.

Total aortic arch repair with double-fenestrated physician-modified endografts, at least 3-year follow-up

OBJECTIVE

This study aims to report the efficacy and safety of double-fenestrated physician-modified endovascular grafts (PMEGs) for total aortic arch repair with at least 3 years of follow-up.

METHODS

All consecutive patients with a pathological aortic arch who underwent aortic arch repair combined with a homemade double-fenestrated stent graft from 2017 to 2020 were reviewed.

RESULTS

74 patients were treated for pathological arch conditions with a double-fenestrated PMEG. Of these, 81% were male, the mean age was 69.9 years, and 59% were classified as American Society of Anesthesiology 3 or 4. Thirty-five percent were treated for a postdissection aneurysm, 36% for a degenerative aneurysm, and 14% for acute type B dissection. Fifteen percent had supra-aortic trunk dissection. Fenestration on the subclavian artery was performed in 96%; if not, a carotid-subclavian bypass was carried out. Technical success was 100%. The proximal landing zone is consistently in zone 0. Early outcomes revealed a 3% occurrence of type 1 endoleak, which was successfully treated by prompt reintervention. One retrograde dissection occurred, and one patient died from hemorrhage on an iliac conduit. A 5% stroke rate was reported. During long-term follow-up (mean time 40.7 months), one type 1 endoleak appeared and was successfully treated; no type 2 or type 3 endoleak requiring intervention occurred. No stent fractures or migrations were reported. Four percent of patients required reintervention, but no surgical conversion to open surgical repair was needed on the aortic arch. No patient died from a cause related to the main procedure.

CONCLUSIONS

Total aortic arch repair with double-fenestrated PMEGs is associated with acceptable early and midterm major morbidity and mortality. It is suitable for the main aortic pathologies. Moreover, it is easily available for emergency situations.

Aortic arch endovascular branch and fenestrated repair: Initial Canadian experience with novel technology

Objective

The objective is to describe the initial Canadian experience using novel aortic arch branched endograft technologies.

Methods

We performed a retrospective consecutive case series of all patients undergoing aortic arch branched repair with newly available endograft technology since 2020 at our site. We describe the patient characteristics, treatment characteristics, and postoperative outcomes.

Results

Eleven patients received arch branched endografts, indicated for penetrating aortic ulcer in seven patients (64%), arch degeneration after prior aortic dissection repair in three (27%), and acute aortobronchial fistula in one patient (9%). Their average age was 72 ± 7 years. Complete arch repair from zone 0 to 4 was performed in six cases (55%); the remaining repairs landed proximally in zones 1 or 2. Seven repairs used a single retrograde facing inner branch (thoracic branch endoprosthesis; W.L. Gore & Associates), three used double antegrade inner branch (Bolton Relay; Terumo Interventional Systems), and one emergent case used double in situ fenestrations. Seven repairs (64%) used an adjunctive extra-anatomic bypass to complete great vessel perfusion, two of which were created during a prior aortic repair. Inferior vena cava balloon inflow occlusion during deployment was used in all cases. No mortalities, transient or permanent spinal cord paralysis, myocardial infarction, dialysis dependence, venous thromboembolism, or bleeding requiring reintervention occurred. No patient undergoing elective arch branch repair experienced a stroke. The one patient undergoing emergent repair did suffer a stroke. The median length of stay was 5 days (interquartile range, 2-8 days). Two endoleaks developed: a type Ia endoleak successfully treated with a Palmaz stent (Cordis) during the index admission, and a type II endoleak with ongoing sac regression on postoperative follow-up. Postoperatively, one patient suffered a suspected aortic graft infection that was treated with lifelong antibiotics. During a mean radiographic follow-up of 7.2 months, no cases of branch vessel instability (ie, no migration, reintervention, arterial rupture, intraluminal thrombus, occlusion, stenosis, or kinking of the branch grafts) developed. Three patients experienced sac regression of >5 mm, and no patient experienced continued postoperative dilation.

Conclusions

To the best of our knowledge, this is the largest reported Canadian volume of aortic arch repair using novel branched or fenestrated technology. The series demonstrates that a multidisciplinary program and properly selected patients can yield excellent results using endovascular repair for complex aortic arch pathology.

Chimney Technique and Single-Branched Stent Graft for the Left Subclavian Artery Preservation During Zone 2 Thoracic Endovascular Aortic Repair for Type B Acute Aortic Syndromes

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of zone 2 thoracic endovascular aortic repair assisted by the chimney technique or single-branched stent graft for the preservation of the left subclavian artery, and summarize our single-center experience with the techniques.

MATERIALS AND METHODS

From February 2017 to June 2020, 137 patients who underwent left subclavian artery revascularization during zone 2 thoracic endovascular aortic repair were enrolled. Patients had acute type B aortic dissection and penetrating aortic ulcer associated with intramural hematoma. The chimney technique was performed in 68 patients (group A), and single-branched stent graft was deployed in 69 patients (group B). All procedures were performed during the acute phase. Primary technical success, immediate postoperative endoleak, neurologic complications (stroke or spinal cord ischemia), 30-day mortality, 1-year technical success, all-cause mortality, patency of the left subclavian artery, and reintervention were analyzed. Comparing the occurrence of the Bird-Beak Configuration, defined as a gap between the aortic wall and the sent graft with stent protrusion into the aortic lumen more than 5 mm, was also performed.

RESULTS

Primary technique success was achieved in 66 and 67 patients in groups A and B, respectively. The incidence of immediate postoperative endoleak, neurologic complications (stroke or spinal cord ischemia), and 30-day mortality were 5.9%, 1.5%, and 4.4% in group A, and 2.9%, 2.9%, and 2.9% in group B, respectively. During follow-up, the 1-year technical success rate was similar in both groups. All-cause mortality was similar in both groups (3.1% in group A and 4.5% in group B). The patency of the left subclavian artery was not significantly different between the 2 groups with 2 and 3 occlusions in groups A and B, respectively. The rate of reintervention was higher in group B (3.1% vs 1.6%, p=0.536), with a non-significant difference. Bird-Beak Configuration was more prominent in group B with the incidence of 59.42%.

CONCLUSIONS

Acting as minimally invasive alternatives, both techniques are feasible for left subclavian artery preservation during zone 2 thoracic endovascular aortic repair for type B acute aortic syndromes with encouraging mid-term outcomes. Long-term follow-up is required to confirm these findings.

Structural numerical analysis of a branched modular stent-graft for aneurysms encompassing all zones of the aortic arch

The development of stent-grafts for the total repair of aneurysms in the aortic arch is still a technical challenge due mainly to the anatomical complexity of this region. Research performed here structurally evaluated a modular branched stent-graft for aneurysms encompassing all zones of the aortic arch by means of numerical simulations using fluid-structure interaction. The geometric domain obtained by means of computed tomography was subjected to physiological boundary conditions. The blood was modelled as non-Newtonian by the Carreau model, and the arterial wall was modelled as anisotropic hyperelastic by the Holzapfel model. The material adopted for the stents was Nitinol, and expanded polytetrafluoroethylene (ePTFE) was used for the graft. A comparison of the structural behaviour of the aneurysmal aortic arch before and after stent-graft implantation was performed. The numerical flow model was experimentally verified in vitro on a representative test bench of blood flow in the aortic arch. The stent-graft was shown to minimally modify arterial wall dynamics and was not susceptible to migration and endoleak. Peak stresses and strains were found in the stents and graft, respectively, while the stresses in the aneurysm sac were significantly reduced, of the order of 97.5%, due to the isolation of the arterial wall by the stent-graft.

Endovascular Repair of Zone 0 Ascending Aortic Pseudoaneurysm: A Case Report

Although open surgery is standard of care for ascending aortic pathology, endovascular approaches can be viable options. We report the case of a 77-year-old man with a 5.7-cm ascending aorta penetrating ulcer. Given his age and clinical profile, the patient underwent Zone 0 thoracic endovascular aortic repair.

Complete zone 0-10 aortic endovascular reconstruction

To the best of our knowledge, the present report is the first on the safety and efficacy of complete endovascular aortic reconstruction from zone 0 to 10 using a standardized approach and parallel stent graft configurations in high-risk patients considered unfit for surgery. During a 7-year period, five patients with complex thoracoabdominal aortic aneurysms and dissections involving zone 0-10 presented with rupture (n = 1; 20%), were symptomatic (n = 2; 40%), or had an aortic pseudoaneurysm (n = 2; 40%) and underwent complete endovascular zone 0-10 reconstruction using off-the-shelf stent grafts in parallel configurations that included chimneys, periscopes, and endovascular docking stations. The zone 0-5 complete arch chimney thoracic endovascular repair included chimneys that extended from the ascending thoracic aorta to the innominate, left common carotid, and left subclavian arteries and a thoracic stent graft extending from zone 0 to 5. The zone 5-10 aortic reconstructions were staged. Stage 1 included either thoracic stent graft and antegrade four visceral chimney placement or abdominal aortic stent graft and retrograde four visceral chimney placement. Stage II included completion of the remainder of the aortic reconstruction with cerebrospinal fluid drainage. A total of 15 aortic procedures included 34 chimneys (14 aortic arch and 20 visceral). Two patients (40%) underwent zone 0-5 aortic reconstruction first, and three patients (60%) underwent zone 5-10 aortic reconstruction first. The incidence of 30-day mortality, spinal cord ischemia, myocardial infarction, stroke, and visceral ischemia was 0%. At a mean follow-up of 4.5 ± 3.1 years, the aortic reconstruction-related mortality was 0%. All-cause mortality was 20%; one patient had died of pneumonia at 3 years postoperatively. Two endoleaks each occurred in zone 0-5 and zone 5-10 (40% for both groups). All endoleaks were treated with coil embolization. Complete endovascular zone 0-10 aortic reconstruction using parallel stent grafts with a docking station is a feasible and relatively safe technique that offers the ability to customize off-the-shelf devices for the treatment of high-risk patients with limited morbidity and mortality.

Homemade fenestration and chimney techniques for the left subclavian artery revascularization during zone 2 thoracic endovascular aortic repair

Background

To investigate the safety and efficacy of homemade fenestration and chimney techniques for the left subclavian artery (LSA) revascularization during zone 2 thoracic endovascular aortic repair (TEVAR).

Methods

From February 2017 to February 2021, 41 patients undergoing fenestration technique (group A) and 42 patients undergoing chimney technique (group B) to preserve the LSA during zone 2 TEVAR were enrolled in the present study. The procedure was indicated for dissections with unsuitable proximal landing zone with refractory pain and hypertension, rupture and malperfusion, and high-risk radiographic features. The baseline characteristics, peri-procedure, and follow-up clinical and radiographic data were recorded and analyzed. The primary endpoint was clinical success, and the secondary endpoints were rupture-free survival, LSA patency, and complications. Aortic remodeling, defined as patency, partial and complete thrombosis of the false lumen, was also analyzed.

Results

Technical success was achieved in 38 and 41 patients in groups A and B, respectively. Four intervention-related deaths were confirmed, two in each group. Immediate post-procedural endoleaks were detected in two and three patients in group A and B, respectively. No other major complications were found in either group, except for one retrograde type A dissection in group A. During follow-up, the initial clinical success rates were 90.24% and 92.86% in groups A and B, respectively. The primary and secondary mid-term clinical success rates were 87.5% and 90% in group A, and both of them were 92.68% in group B. Rupture-free survival and LSA patency were not significantly different between the two groups. The incidence of complete thrombosis in the aorta distal to the stent graft was 67.65% and 61.11% in groups A and B, respectively.

Conclusions

Apart from the lower clinical success rate of fenestration technique, both physician-modified techniques are available for LSA revascularization during zone 2 TEVAR and significantly promote favorable aortic remodeling.

Aortic haemodynamics and wall stress analysis following arch aneurysm repair using a single-branched endograft

Introduction

Thoracic endovascular aortic repair (TEVAR) of the arch is challenging given its complex geometry and the involvement of supra-aortic arteries. Different branched endografts have been designed for use in this region, but their haemodynamic performance and the risk for post-intervention complications are not yet clear. This study aims to examine aortic haemodynamics and biomechanical conditions following TVAR treatment of an aortic arch aneurysm with a two-component single-branched endograft.

Methods

Computational fluid dynamics and finite element analysis were applied to a patient-specific case at different stages: pre-intervention, post-intervention and follow-up. Physiologically accurate boundary conditions were used based on available clinical information.

Results

Computational results obtained from the post-intervention model confirmed technical success of the procedure in restoring normal flow to the arch. Simulations of the follow-up model, where boundary conditions were modified to reflect change in supra-aortic vessel perfusion observed on the follow-up scan, predicted normal flow patterns but high levels of wall stress (up to 1.3M MPa) and increased displacement forces in regions at risk of compromising device stability. This might have contributed to the suspected endoleaks or device migration identified at the final follow up.

Discussion

Our study demonstrated that detailed haemodynamic and biomechanical analysis can help identify possible causes for post-TEVAR complications in a patient-specific setting. Further refinement and validation of the computational workflow will allow personalised assessment to aid in surgical planning and clinical decision making.

A Systematic Review of Contemporary Outcomes from Aortic Arch In Situ Laser Fenestration During Thoracic Endovascular Aortic Repair

BACKGROUND

In situ laser fenestrated endovascular aortic repair (L-FEVAR) is a novel and creative solution for complex aortic pathologies in the urgent and emergency setting. Outcomes of this technique, however, are poorly reported. We sought to evaluate the efficacy, safety, and outcomes of L-FEVAR in aortic arch pathologies.

METHODS

A systematic literature review and analysis were conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses and Cochrane guidelines. A search was conducted using Google, PubMed, and Scopus to identify studies evaluating L-FEVAR. Two independent reviewers determined study inclusion. Case reports and series including < 10 patients were excluded. Reviewers also assessed the methodological quality and extracted data regarding outcomes. A meta-analysis of endoleak event rates was conducted using a fixed-effect model due to small sample size.

RESULTS

Eight studies met inclusion criteria between 2013 and 2021. Most studies were retrospective (87.5%) with median follow-up duration of 12.5 months (range 10-42). There were 440 patients included (range 15-148), mostly men (64%). Mean age was 61 years (range 53-68). Included patients were all symptomatic with L-FEVAR being technically successful in 93.3% of cases. The main indication for aortic arch intervention was aortic dissection. Single fenestrations occurred most frequently (68%), followed by triple (22%) then double fenestrations (9%). Meta-analysis of 8 studies (n = 440) demonstrated an endoleak event rate of 0.06 (95% confidence interval 0.04-0.09, P < 0.001) with no observed statistically significant heterogeneity of effects (Q = 7.91, P = 0.34). The median operative time was 162 min (range 53-252) with median length of stay of 10 days (range 7-17). Primary branch patency was 96.6%. Secondary patency rate was 97%. Pooled complication rates such as endoleak occurred in 4.8%, stroke in 2.0%, spinal cord ischemia in 0.2%, retrograde dissection in 0.9%, and 30-day death in 2.0%. Access complications occurred in 0.4%. Antiplatelet regimen was poorly reported in the study cohort.

CONCLUSIONS

In situ laser fenestration is a feasible, safe, and effective approach to treat aortic arch disease in patients who are unsuitable for open or custom-made endovascular means. High technical success and excellent short-term branch patency can be achieved. These single-institution series exhibit promising short-term outcomes. In a similar paradigm to investigational device exemptions studies for custom-made and physician modified endografts, these preliminary data make a persuasive argument for larger long-term multi-institutional prospective study of this promising technique.

NEXUS Arch: A Multicenter Study Evaluating the Initial Experience With a Novel Aortic Arch Stent Graft System

OBJECTIVE

To assess the initial clinical experience with a novel endograft system (NEXUS Aortic Arch Stent Graft System) designed to treat aortic arch pathologies and address the morphology and hemodynamic challenges of the aortic arch.

SUMMARY BACKGROUND DATA

The aortic arch remains the most challenging part of the aorta for both open and endovascular repair. Transcatheter aortic arch repair has the potential to significantly reduce surgical risks.

METHODS

Patients underwent transcatheter aortic arch repair with a single branch, 2 stent graft system, implanted over a through-and-through guidewire from the brachiocephalic trunk, to the descending aorta with an ascending aorta stent graft. The ascending aorta stent graft is deployed into a designated docking sleeve to connect the 2 stent grafts and isolate the aortic arch pathology. Proximal landing zone in all cases was in Zone 0. Anatomical inclusion criteria included adequate landing zone in the ascending aorta, brachiocephalic trunk, and descending thoracic aorta. Preparatory debranching procedure was performed in all patients with carotid-carotid crossover bypass and left carotid to left subclavian bypass, or parallel graft from descending aorta to left subclavian artery. Safety and performance were evaluated through 1 year. Survival analysis used the Kaplan-Meier method.

RESULTS

Twenty-eight patients, 79% males, with a mean age of 72.2 ± 6.2 years were treated with 100% procedural success. Isolated aortic arch aneurysm was the principle pathology in 17 (60.7%) of patients, while chronic aortic dissection was the principle pathology in 6 (21.4%) of patients. The remaining 5 (17.8%) had combined or other pathologies. At 1 month, the vascular pathology was excluded in 25 of 26 alive patients (96.1%). The 30 days mortality rate was 7.1%, stroke rate was 3.6% (all nondisabling), and combined mortality/stroke rate was 10.7%. One-year mortality was 10.7%, without device or aneurysm-related death. Two patients (7.1%) reported stroke or transient ischemic attack at 1 year that recovered completely. One year combined mortality/stroke rate was 17.8%. There were 3 patients (10.7%) that had device-related unplanned reinterventions through 1 year.

CONCLUSIONS

The NEXUS Aortic Arch Stent Graft System, a novel single branch, 2 stent graft system used for endovascular aortic arch repair that requires landing in the ascending aorta, demonstrates a high success rate with excellent 1 year safety and performance.

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.

Ascending Thoracic Aortic TEVAR with Chimney Stent Graft to Free Vein Coronary Bypass for Ruptured Type A Aortic Dissection

The standard treatment for ruptured type A aortic dissection is open surgical repair. We have described the case of a frail patient with home oxygen-dependent chronic obstructive pulmonary disease and prior free vein circumflex coronary artery bypass who had presented with a ruptured type A aortic dissection and was deemed too high risk for open surgery. On July 7, 2017, the patient underwent emergent endovascular ruptured ascending thoracic aortic aneurysm repair with a chimney stent graft to a free vein coronary bypass that originated from the ascending thoracic aorta. The procedure was uneventful, and the patient was discharged home on postoperative day 1.

Complete Endovascular Reconstruction of the Canine Ascending Aorta, Aortic Arch, and Supra-Aortic Vessels by Implanting a New Unibody Outer Double-Branched Stent-Graft

PURPOSE

We evaluated the feasibility and safety of using a new unibody outer double-branched stent-graft system to reconstruct the canine ascending aorta, aortic arch, and supra-aortic vessels.

MATERIALS AND METHODS

The outer-branched stent-graft was a unibody design. The branched stent-graft consisted of a main stent-graft and 2 branches. The introducer system included a tri-channel catheter, 2 detachable sleeves, a front fixing device, a constraining wire, and a curved outer sheath. The branched stent-graft was loaded into the introducer system. Ten adult mongrel dogs underwent general anesthesia, and the branched stent-grafts were deployed into the canine ascending aorta, aortic arch, and supra-aortic vessels by the introducer system. All animals were followed up for 3 months. At the end of the follow-up period, computed tomographic angiography (CTA) was performed to observe the patency of the branched stent-grafts.

RESULTS

The mean operation time was 142.7±13.7 minutes. The mean fluoroscopy time was 20.73±2.22 minutes. The mean dosage of contrast agent was 95.9±8.7 mL. During the operation, the tri-channel catheters successfully paralleled the wires in the aorta. All 10 branched stent-grafts were successfully implanted into the canine ascending aorta and aortic arch. There were no symptoms of cerebral embolization and no incision infection during the follow-up period. Computed tomographic angiography and specimens showed that the branched stent-grafts and native vessels were patent, the inner surfaces of the branched stent-grafts were covered by neointima, and there was no retrograde aortic dissection in the ascending aorta.

CONCLUSIONS

This animal research demonstrated that the unibody outer double-branched stent-graft system could be applied to reconstruct the canine ascending aorta, aortic arch, and supra-aortic vessels.

CLINICAL IMPACT

Thoracic endovascular aortic repair has been the main treatment method for aortic aneurysms or dissections involving the descending thoracic aorta. However, the aortic arch and ascending aorta remain the last segments of the aorta without a validated and routinely used endovascular option. In this research, we designed a new unibody outer branched stent-graft system to reconstruct the distal ascending aorta, aortic arch and supra-aortic vessels. The unibody outer branched stent-graft system could be applied to treat aortic pathologies which involve the middle and distal proximal ascending aorta, aortic arch and proximal descending aorta.

Favorable neurological outcomes in thoracic endovascular aortic repair with RELAY™ branched-An international perspective

BACKGROUND

While open surgical repair continues to be the mainstay option for aortic arch reconstruction, the associated mortality, morbidity, and high turn-down rates have led to a need for the development of minimally invasive options for aortic arch repair. Though RELAY™ Branched (Terumo Aortic, Inchinnan, UK) represents a promising option for complex endovascular aortic arch repair, neurological complications remain a pertinent risk. Herein we seek to present multicenter data from Europe documenting the neurological outcomes associated with RELAY™ Branched.

METHODS

Prospective data collected between January 2019 and January 2022 associated with patients treated with RELAY™ single-, double-, and triple-branched endoprostheses from centers across Europe was retrospectively analyzed with descriptive and distributive analysis. Follow-up data from 30 days and 6, 12, and 24 months postoperatively were included. Patient follow-up was evaluated for the onset of disabling stroke (DS) and non-disabling stroke (NDS).

RESULTS

Technical success was achieved in 147 (99.3%) cases. Over 24 months period, in total, six (4.1%) patients suffered DS, and eight (5.4%) patients suffered NDS after undergoing aortic arch repair with RELAY™. All patients that developed postoperative DS had been treated with the double-branched RELAY™ endoprosthesis.

DISCUSSION

The data presented herein demonstrates that RELAY™ Branched is associated with favorable neurological outcomes and excellent technical success rates. Key design features of the endoprosthesis and good perioperative management can contribute greatly to mitigating neurological complications following endovascular aortic arch repair.

A canine model of aortic arch aneurysm created with autologous pericardium

Background

To establish a canine model of aortic arch aneurysm that is suitable for research on new devices and techniques applied to the aortic arch.

Materials and methods

Fifteen mongrel dogs underwent surgery. The autologous pericardial patch was sewn on the aortotomy site in the anterior wall of the aortic arch. The animals were followed up for 3 months postoperatively. Computed tomography angiography was used to visualize and measure the aneurysm model. Hematoxylin and eosin staining was used to observe the histological characteristics of the aneurysm model. Changes in aneurysm diameter over time were analyzed using analysis of variance.

Results

One dog died of hemorrhage during surgery. Fourteen dogs survived the surgical procedure. Two of them died on the first postoperative day because of ruptures at the suturing margin. The diameter of the aneurysm model was twice as large as that of the aortic arch. There was no significant change in the maximum diameter of the aneurysm model during the follow-up period.

Conclusions

We established a controllable and stable aortic arch aneurysm model created with an autologous pericardium patch. The aneurysm model can be used to research endoleaks after thoracic endovascular aortic repair and new endovascular techniques can be applied to the aortic arch.

In Vivo Quantification of Cardiac-Pulsatility-Induced Motion Before and After Double-Branched Endovascular Aortic Arch Repair

The Relay^®Branch stent-graft (Terumo Aortic, Sunrise, FL, USA) offers a custom-made endovascular solution for complex aortic arch pathologies. In this technical note, a modified electrocardiography (ECG)-gated computed tomography (CT)-based algorithm was applied to quantify cardiac-pulsatility-induced changes of the aortic arch geometry and motion before and after double-branched endovascular repair (bTEVAR) of an aortic arch aneurysm. This software algorithm has the potential to provide novel and clinically relevant insights in the influence of bTEVAR on aortic anatomy, arterial compliance, and stent-graft dynamics.

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.

Surgical Debranching versus Branched Endografting in Zone 2 Thoracic Endovascular Aortic Repair

INTRODUCTION

Left subclavian artery (LSA) revascularization is recommended in patients undergoing elective thoracic endovascular aortic repair (TEVAR) with proximal zone 2 landing requiring coverage of the LSA. The gold-standard remains surgical LSA revascularization, but recently the feasibility of branched endografts has been demonstrated. We compared the perioperative and mid-term outcomes of these approaches.

METHODS

A retrospective review of consecutive patients undergoing TEVAR with proximal zone 2 landing at a single center from 2014-2020 was performed. Patients were divided into cohorts for comparison: those undergoing surgical revascularization (SR-TEVAR group) and those undergoing thoracic branched endografting with an investigational device (TBE group). Patients who did not receive LSA revascularization were excluded. Perioperative outcomes including procedural success, death, stroke, limb ischemia, and length of stay were compared. Kaplan-Meier survival curves were compared with the log-rank test. The cumulative incidences of device-related endoleak (type I and III) and device-related reintervention, accounting for death as a competing hazard, were compared with the Fine-Gray test.

RESULTS

A total of 55 patients were included: 31 (56%) SR-TEVAR and 24 (44%) TBE. Preoperative demographics and comorbidities were similar between the groups. Procedural success was 100% in both cohorts, and there were no periprocedural strokes or left upper extremity ischemic events. One operative/30-day mortality (TBE 4.2% vs SR-TEVAR 3.2%, p=0.99) occurred in each cohort. Total operative time (minutes, TBE 203 ± 79 vs SR-TEVAR 250 ± 79 p=0.03) and total length of stay (days, TBE 5.2 ± 3.6 vs SR-TEVAR 9.9 ± 7.2, p=0.004) were both significantly shorter in the TBE group. There was no difference in mid-term survival (log-rank p=0.50), nor the cumulative incidence of device-related endoleak (Fine-Gray p=0.51) or reintervention (Fine-Gray p=0.72). There have been no occlusions of the TBE graft nor surgical bypass/transpositions after a mean follow-up for 28 ± 16 and 34 ± 24 months, respectively.

CONCLUSIONS

Thoracic branched endografting can be performed with similar procedural success and comparable safety profile to TEVAR with surgical revascularization, while reducing total length of stay, in patients requiring proximal zone 2 coverage. Mid-term outcomes of each approach are also similar. Prospective, randomized comparisons of these techniques are warranted.

Comparison of the Outcomes of Total Endovascular Aortic Arch Repair Between Branched Endograft and Chimney Endograft Technique in Zone 0 Landing

PURPOSE

Zone 0 landing in thoracic endovascular aortic repair (TEVAR) has recently gained increasing attention for the treatment of high-risk patients. The aim of this study was to compare the outcomes of total endovascular aortic arch repair between branched TEVAR (bTEVAR) and chimney TEVAR (cTEVAR) in the landing zone (LZ) 0.

MATERIALS AND METHODS

This was a single-center, retrospective, and observational cohort study. From January 2010 to March 2020, 40 patients (bTEVAR, n=25; cTEVAR, n=15; median age: 79 years) were enrolled in this study, with a median follow-up period of 4.1 years. These patients were considered unsuitable for open surgical treatment.

RESULTS

All procedures were successful and no cases of conversion to open repair were noted during the 30-day postoperative period. The 30-day mortality was 2.5% (n=1; bTEVAR [0 of 25, 0%] vs cTEVAR [1 of 15, 6.7%]; p=0.375), the perioperative stroke rate was 10.0% (n=4; bTEVAR [4 of 25, 16.0%] vs cTEVAR [0 of 15, 0%], p=0.278), and type 1a endoleak rate was 15.0% (n=6; bTEVAR [0 of 25, 0%] vs cTEVAR [6 of 15, 40.0%], p=0.001). The risk factor for stroke was atheroma grade of ≥2 in the brachiocephalic artery (p<0.001). The risk factor for type 1a endoleak was cTEVAR (p=0.001). The 8-year survival rate was 49.9%. The aorta-related death-free rate and aortic event-free rate at 8 years were 94.4% (bTEVAR: 95.5% vs cTEVAR: 93.3%, p=0.504) and 60.7% (bTEVAR: 70.7% vs cTEVAR: 40.0%, p=0.048), respectively.

CONCLUSIONS

Total endovascular aortic arch repair using bTEVAR and cTEVAR is feasible for the treatment of aortic arch diseases in high-risk patients who are unsuitable for open surgery. However, as the rate of stroke is high, strict preoperative evaluation to prevent stroke is needed. No rupture of the aneurysm was observed in cTEVAR, but patients should be selected carefully because of the high incidence of type 1a endoleak.

Procedure-Associated Costs and Mid-Term Outcomes of Endovascular Zone 0 and Zone 1 Aortic Arch Repair

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) of proximal aortic arch pathology provides a less-invasive treatment option for high-risk patients ineligible for open arch reconstruction. However, the fiscal impact of these techniques remains unclear. Therefore, our objective was to characterize the mid-term outcomes after Zone 0 and Zone 1 TEVAR and describe the associated technical costs, revenues, and net margins at a single tertiary medical center.

METHODS

We examined all patients who underwent TEVAR between April 2011 and August 2019 via retrospective chart review. Patients were categorized by proximal endograft extent to identify Zone 0 or Zone 1 repairs. Procedural characteristics and outcomes were described. Technical costs, revenues, and margins were obtained from the hospital finance department.

RESULTS

We identified 10 patients (6 Zone 0, 4 Zone 1) who were denied open arch reconstruction. Patients were predominantly female (n = 8; 80%) and the mean age was 72.8 ± 5.5 years. TEVAR was performed in 5 asymptomatic patients, urgently in 3 symptomatic patients, and emergently in 2 ruptured patients. TEVAR plus extra-anatomic bypass was performed in 4 patients. Another 4 patients also received parallel stent-grafting while 1 patient received a branched thoracic endograft and yet another an in-situ laser fenestration followed by branch stent grafting. Within the 30-day postoperative period, 1 patient experienced stroke and 1 patient died. Bypass and branch vessel patency were 100% through the duration of follow-up (mean 19.3 months). Mean total technical cost associated with all procedures or repair stages was $105,164 ± $59,338 while mean net technical margin was -$25,055 ± $18,746. The net technical margin was negative for 9 patients.

CONCLUSIONS

Endovascular repair of the proximal aortic arch is associated with good mid-term outcomes in patients considered too high-risk for open repair. However, reimbursement does not adequately cover treatment cost, with net technical margins being negative in nearly all cases. To remain financially sustainable, efforts should be made to both optimize aortic arch TEVAR delivery as well as advocate for reimbursement commensurate with associated costs.

Update on Trials & Devices for Endovascular Management of the Ascending Aorta and Arch

Thoracic endovascular aortic repair (TEVAR) may treat a variety of acute and chronic aortic diseases as described in several articles in this issue of TVIR. A major challenge to endovascular treatment in the thoracic aorta is disease involving or in close proximity to the aortic valve, coronary arteries, or aortic arch branch vessels. Disease involving the ascending aorta in particular has significant limitations based on its distance from the aortic root. The left subclavian artery (LSA) can be covered in the emergent setting to ensure an adequate landing zone, but patients may require later surgical revascularization, and any coverage of the carotid arteries would require definite pre-endograft revascularization. Open surgical repair continues to have high morbidity and mortality rates in the acute setting, and endovascular therapy is preferred if feasible. Ad hoc modifications of current endografts to maintain arch vessel patency include placement of chimney/snorkel stents or custom fenestrations. However, there is a need for commercially available "off-the-shelf" ascending arch stent-grafts and branched stent-grafts that allow for complete endovascular repair of the aortic arch. This review will focus on devices under investigation for the treatment of pathologies involving the ascending aorta and aortic arch.

Experimental Analysis of In Situ Fenestration of Endovascular Stent-Grafts: Comparison between Needle and Laser Puncture

BACKGROUND

To evaluate the quality of in vitro fenestrations during in situ fenestration (ISF) and investigate the differences between needle and laser puncture in current stent-grafts.

METHODS

An in vitro study evaluated the damage created by needle ISF on stent-graft fabrics versus laser ISF. Fenestrations were made in 5 different commercially available stent-grafts, including polyester stent-grafts (Relay, Valiant and Hercules) and expanded polytetrafluoroethylene (ePTFE) stent-grafts (TAG and Ankura). Each stent-graft received fenestration by needle and laser separately, followed by gradual dilation (4 mm, 6 mm, 8 mm, and 10 mm sequentially) of noncompliant balloons. Quantitative and qualitative evaluations including fenestration diameter, area, shape and margins were conducted using light microscopy and scanning electron microscope.

RESULTS

The primary fenestrations created by needle were slit-like with visible cut-off fibers in polyester stent-grafts and were almost circular with clear margins in ePTFE stent-grafts; those created by laser were squared or elliptical with ragged edges and burned fibers in all the stent-grafts. Fabric debris and toxic particles due to burning of the material were generated during laser-assisted fenestration. The Primary holes in polyester stent-grafts (Relay, Valiant and Hercules) by needle showed smaller area (0.05 mm² vs. 0.22 mm2, 0.52 mm² vs. 0.70 mm² and 0.28 mm² vs. 0.46 mm²; P < 0.01) and worse shape (0.93 vs. 2.46, 1.17 vs. 2.33 and 0.93 vs. 2.47; P < 0.01) than those by laser, while larger area (0.67 vs.0.43, 0.59 vs.0.45; P < 0.05), better shape (3.93 vs. 2.53, 3.90 vs. 2.93; P < 0.05) and better margin (3.83 vs. 2.47, 3.83 vs. 2.53; P < 0.05) in ePTFE stent-grafts (TAG and Ankrura). After gradual balloon dilation, the final holes showed no evident difference in maximal length, fenestration area, scores of shape and margin between the 2 ways of fenestration (P > 0.05). Ankura stent-graft showed the largest holes with best quality than the others.

CONCLUSIONS

The primary fenestrations were different between needle and laser puncture, laser induced fabric debris and toxic particles release should be cautiously considered. The final fenestrations were similar after gradual balloon dilation.

Aortic arch stenting: current strategies, new technologies and future directions

Operating on the aortic arch is a formidable challenge. Open operations remain the gold standard, but despite improvement in technique and outcomes, they are still associated with significant morbidity and mortality. The last 20 years have seen a remarkable reduction in the operative morbidity associated with treatment of the descending thoracic aorta using thoracic endovascular aneurysm repair (TEVAR). To improve outcomes following arch repair, new TEVAR devices, including both single-branched and multibranched designs, have come to clinical trial. This review discusses the modern state of open and hybrid repairs while introducing the reader to technology for endovascular therapy of the aortic arch. We describe important anatomical and operative considerations for the devices. Given these nuances, we believe the future of the aortic arch to be patient-individualised hybrid repairs, involving both open and endovascular options with a multidisciplinary 'thoracic aorta team' at the helm.

Long-Term Outcomes of Thoracic Endovascular Repair for Aortic Arch Dissection Using Customized Single-Branched Fenestrated Stent-Graft

OBJECTIVES

To report outcomes of thoracic endovascular repair using customized single-branched fenestrated stent-grafts in treatment of aortic arch dissections.

MATERIALS AND METHODS

Between November 2009 and November 2011, 16 patients with aortic arch dissections underwent thoracic endovascular aortic repair utilizing customized unibody single-branched fenestrated stent-graft (UBFSG) in our institution.

RESULTS

All 16 patients were male with mean age of 54.50 ± 11.33. The technical success rate was 100%. 30-day mortality rate was 6.25% (n = 1). The median follow-up period was 98 months (range, 0-119). During follow-up, 4 nonaorta-related deaths were recorded. Two (2) cases of left subclavian artery occlusion were observed 12 and 14 months after the operation. Two (2) patients had another successful endovascular repair in time, including one case of type Ib endoleak occurred 100 months after the operation and one case of stent-graft induced new entry tear 38 months after the operation. No stroke and migration of stent-grafts were observed.

CONCLUSIONS

The branched fenestrated stent-graft may be an effective alternative treatment for aortic arch dissections unfit for open surgery.

Aortic arch aneurysm repair - Unsteady hemodynamics and perfusion at different heart rates

The aortic arch aneurysm is a complex disease that requires branching of one or more aortic arch vessels and can be fatal if left untreated. In this in vitro study, we examine the effect of the treatment approach on the unsteady hemodynamics and blood perfusion to the upper vessel's in models of an aortic arch aneurysm, and of the three common repair approaches: open-chest surgical repair, chimney, and hybrid approach. A particle image velocimetry method was used to quantify the unsteady hemodynamics in the four models simulated in a mock circulatory loop, to evaluate unsteady hemodynamic parameters and measure perfusion to the brain and the upper body. According to the findings, in terms of perfusion to the brain and upper body, the surgery model has the highest flow rate comparing to the other models in most heart-rate conditions. It also shows oscillatory parameters in the upper vessels which in normal arteries are correlated with a better arterial function. Between the two endovascular procedures, the hybrid model exhibits slightly better hemodynamic characteristics than the chimney model, with lower shear stresses and more oscillatory flow and WSS in the upper vessels. The hybrid model had lower perfusion flow rates to upper vessels during rest conditions (90BPM). However, unlike the other models, perfusion in the hybrid model increased with heart rate, thus at 135 BPM, it results in flow rate to upper vessels similar to that of the chimney model. The results of this study may shed light on future endograft' design and placement techniques.

Evaluation for the safety and effectiveness of the in situ fenestration system in TEVAR for aortic arch pathologies: protocol for a prospective, multicentre and single-arm study

INTRODUCTION

Thoracic endovascular aortic repair (TEVAR) has gradually become the mainstream therapy for aortic arch pathologies (AAP). Our centre developed the in situ fenestration (ISF) system according to years of clinical experience and technological innovation. This study aims to evaluate the safety and effectiveness of the innovative, self-developed ISF system in TEVAR for AAP.

METHODS AND ANALYSIS

The study is a prospective, multicentre and single-arm study. Patients diagnosed with AAPs in five centres on 1 January 2021 will be recruited and general TEVAR with ISF system will be performed. Clinical information and CT angiography images will be collected and recorded. Patients will be followed up for 5 years. Safety and efficacy endpoints are planned to be reported to evaluate this self-developed ISF system.

ETHICS AND DISSEMINATION

The study is a registry. We have registered the study on the Chinese Clinical Trial Registry website (http://www.chictr.org.cn/). This study has been approved by the Ethics Committee of Zhongshan Hospital Fudan University (B2020-371) and individual consents will be signed at the time of enrolment. We anticipate that this self-developed ISF system will result in favourable social and economic benefits. Findings will be disseminated in peer-reviewed journals to provide reference for future clinical practice.

TRIAL REGISTRATION NUMBER

ChiCTR1900026696.

Clinical trial outcomes and thoracic aortic morphometry after one year with the Valiant Navion stent graft system

AUTHORS' NOTE

On February 17, 2021, Medtronic Incorporated issued a global voluntary recall of the Valiant Navion Thoracic Stent Graft System (the device under study in the Valiant Evo Global Clinical Program that is the subject of this publication), and instructed physicians to immediately cease use of the Valiant Navion system and return any unused product. Medtronic initiated the recall in response to three clinical trial subjects recently observed with stent fractures, two of whom have confirmed type IIIb endoleaks. The data collection, analysis, and manuscript submission occurred before the notice of this recall, and, specifically, the 100 procedures reviewed for this series were free of events at 1 year related to the reason for this device recall. The authors of this article and the manufacturer were unaware of the recently detected adverse events at the time of the preparation of the manuscript, and the 1-year trial results, and imaging-based analyses described are unchanged. Management of thoracic aortic aneurysms continues to be a challenging problem and outcomes are dependent on patient anatomy. The present publication focuses on the importance of achieving proximal and distal seals and the consideration of the temporal changes of the aortic morphology as a part of the TEVAR planning process. The authors believe there is still scientific merit in disclosing this information, despite the current nonavailability of the Valiant Navion system.

OBJECTIVE

The Valiant Navion stent graft system (Medtronic Inc, Santa Rosa, Calif) is a third-generation device with improved conformability. We have reported the 1-year clinical trial outcomes, with a focus on an imaging-based analysis of the aortic morphology. We assessed the effects of graft implantation on the native anatomy and the effects of the 1-year changes in thoracic aorta morphology on the original seal zones of the stent graft.

METHODS

A total of 100 subjects were enrolled in a prospective single-arm clinical trial investigating the Valiant Navion stent graft system. An independent core laboratory (Syntactx, New York, NY) assessed the anatomic characteristics and performance outcomes.

RESULTS

Through 1 year of follow-up, the freedom from all-cause mortality, aneurysm-related mortality, and secondary procedures was 89.8%, 97.0%, and 94.8% respectively. Of the 100 patients, 5 had undergone a total of six secondary procedures, and 9 patients had developed an endoleak (type Ia and Ib in 1, type Ia in 1, type Ib in 3, and type II in 4 patients) within the first year. After 1 year, 2 of 76 patients (2.6%) had had an increase in their maximum aneurysm diameter of ≥5 mm, 62 (81.6%) had had stable sacs, and 12 (15.8%) had experienced sac shrinkage. Although no deployment failures had occurred, 36 of the 100 proximal (36%) and 31 of the 100 distal (31%) attachment zones were considered short according to our definitions. The stent graft had conformed to the native anatomy at implantation, because the preprocedural thoracic aorta tortuosity (1.45 ± 0.02) had not significantly changed at 1 month after implantation (1.46 ± 0.02). Despite a natural increase in thoracic tortuosity after 1 year (1.49 ± 0.02), wall apposition had been maintained over time, as evidenced by the low endoleak rates. Aortic elongation and dilation had occurred at the proximal end of the graft by an average of 1.2 mm and 1.6 mm, respectively. Aortic remodeling was more pronounced at the distal end, with an average increase of 4.2 mm in length and 2.8 mm in diameter.

CONCLUSIONS

The included patients had had positive 1-year outcomes with high freedom from mortality, endoleak development, and secondary procedures. Aortic elongation and dilation were more prevalent at the distal end, emphasizing the importance of distal attachment zone consideration as part of preoperative planning. Because aortic remodeling can be expected to continue over time, additional follow-up and imaging analysis in the trial will be necessary to assess the aortic morphology and its effects on stent graft performance.

Carotid-Axillary Bypass as an Alternative to Carotid-Subclavian Bypass Following Coverage of Left Subclavian Artery During TEVAR

INTRODUCTION

Thoracic Endovascular Aortic Repair (TEVAR) has become the procedure of choice for pathology involving the descending thoracic aorta since its approval by the FDA in 2005. Left subclavian artery (LSA) coverage is commonly required to facilitate an adequate proximal landing zone for the endograft. The traditional revascularization procedure of choice is carotid-subclavian bypass, however recent studies report complication rates as high as 29%-specifically phrenic nerve palsy in 25% of patients undergoing this procedure. Our aim is to present our experience using carotid-axillary bypass as a safe alternative to carotid-subclavian bypass.

METHODS

All patients undergoing carotid-axillary bypass for TEVAR with LSA coverage between June 2016 and September 2019 at a tertiary medical center were retrospectively identified. Short-term and long-term complications were identified and analyzed including: phrenic nerve, recurrent laryngeal nerve, and axillary nerve injuries, as well as local vascular complications requiring re-intervention. All perioperative chest radiographs were reviewed for new hemidiaphragm elevation to assess for phrenic nerve injuries.

RESULTS

35 patients underwent carotid-axillary bypass in conjunction with TEVAR during this time period. The majority of bypasses were performed concurrently with TEVAR (80.0%, 28/35) utilizing GORE PROPATEN 8 mm externally supported vascular graft (91.4%, 32/35). The complication rate specific to carotid-axillary bypass was 14.3% (5/35). We observed a significantly lower (0%, 0/35, P < 0.01) rate of phrenic nerve palsy for carotid-axillary bypass compared to the previously reported 25% (27/107) for carotid-subclavian bypass. For patients with available follow-up imaging (85.7%, 30/35), there was a 100% patency rate at time intervals ranging from 0-1066 days (IQR = 3-37.8).

CONCLUSION

Carotid-axillary bypass can be performed as a safe alternative to carotid-subclavian bypass for LSA coverage during TEVAR involving a more superficial anatomic course of dissection. Phrenic nerve palsy, a well-described complication of the traditional carotid-subclavian bypass, was not observed in this retrospective series.

Hybrid zone zero debranching thoracic endovascular aortic repair of ascending aortic injury after surgery and radiotherapy for breast cancer

Thoracic endovascular aortic repair of the ascending aorta remains challenging. We have reported the case of an 81-year-old woman with ascending aortic injury who underwent a life-saving hybrid repair. The patient had previously undergone extended radical mastectomy and postoperative radiotherapy for breast cancer, which had resulted in a right thoracic wall defect and bone exposure and osteonecrosis of the sternum. Therefore, the ascending aorta was directly compressed by the sternum at the level of the brachiocephalic artery bifurcation, causing persistent bleeding from the thoracic wall. Hybrid zone 0 debranching thoracic endovascular aortic repair with a left subclavian artery inflow was emergently performed and achieved hemostasis.

Ascending aortic rupture after zone 2 endovascular repair: a multiparametric computational analysis

A 74-year-old woman expired from ascending aortic rupture 3 months following branched zone 2 endovascular aortic repair. Multiparametric image-based computational evaluation of this case suggested that the stiffness mismatch between the endograft and the native aorta increased haemodynamic loads and likely led to the rupture of the ascending aorta. This under-recognized phenomenon should be considered in preoperative planning and presents suggestions for endograft development.

Cardiac remodelling following thoracic endovascular aortic repair for descending aortic aneurysms

OBJECTIVES

Current endografts for thoracic endovascular aortic repair (TEVAR) are much stiffer than the aorta and have been shown to induce acute stiffening. In this study, we aimed to estimate the impact of TEVAR on left ventricular (LV) stroke work (SW) and mass using a non-invasive image-based workflow.

METHODS

The University of Michigan database was searched for patients treated with TEVAR for descending aortic pathologies (2013-2016). Patients with available pre-TEVAR and post-TEVAR computed tomography angiography and echocardiography data were selected. LV SW was estimated via patient-specific fluid-structure interaction analyses. LV remodelling was quantified through morphological measurements using echocardiography and electrocardiographic-gated computed tomography angiography data.

RESULTS

Eight subjects were included in this study, the mean age of the patients was 68 (73, 25) years, and 6 patients were women. All patients were prescribed antihypertensive drugs following TEVAR. The fluid-structure interaction simulations computed a 26% increase in LV SW post-TEVAR [0.94 (0.89, 0.34) J to 1.18 (1.11, 0.65) J, P = 0.012]. Morphological measurements revealed an increase in the LV mass index post-TEVAR of +26% in echocardiography [72 (73, 17)  g/m2 to 91 (87, 26)  g/m2, P = 0.017] and +15% in computed tomography angiography [52 (46, 29)  g/m2 to 60 (57, 22)  g/m2, P = 0.043]. The post- to pre-TEVAR LV mass index ratio was positively correlated with the post- to pre-TEVAR ratios of SW and the mean blood pressure (ρ = 0.690, P = 0.058 and ρ = 0.786, P = 0.021, respectively).

CONCLUSIONS

TEVAR was associated with increased LV SW and mass during follow-up. Medical device manufacturers should develop more compliant devices to reduce the stiffness mismatch with the aorta. Additionally, intensive antihypertensive management is needed to control blood pressure post-TEVAR.

Early and midterm results of thoracic endovascular aortic repair using a branched endograft for aortic arch pathologies: A retrospective single-center study

Background

Zone 0 landing hybrid thoracic endovascular aortic repair (TEVAR) includes a few moderately invasive surgical procedures. To reduce invasiveness, TEVAR with a branched aortic arch stent-graft can be considered. This study aimed to elucidate the effectiveness of performing TEVAR using a Bolton (Bolton Medical, Inc, Sunrise, Fla) branched endograft by analyzing early and midterm results.

Methods

We enrolled 28 patients (mean age, 78.4 years) who underwent TEVAR with the Bolton branched endograft in Osaka University Hospital between October 2012 and June 2018 with a mean follow-up period of 4.0 years. Double-side and single-side branched devices were used in 24 (85.7%) and 4 (14.3%) patients, respectively.

Results

All procedures were successful; no cases of endoleak or conversion to open repair were noted during the 30-day postoperative period. The perioperative stroke rate was 14.3% (4 out of 28); midterm stroke was not detected. All patients with perioperative stroke had atheroma grade ≥2 in the brachiocephalic artery. No type 1a endoleak was reported during the early or midterm results. The cumulative survival rate, aorta-related death-free rate, and aortic event-free survival rate at 5 years were 80.8%, 95.8%, and 81.6%, respectively.

Conclusions

We achieved satisfactory early and midterm results by using a Bolton branched endograft for high-risk patients with arch pathologies except for high postoperative stroke. Although this treatment method is associated with postoperative stroke, performing strict evaluation of atheroma may prevent such complication. By preventing intraoperative stroke, TEVAR with this custom-made Bolton branched endograft may be considered a less-invasive treatment.

Trends and outcomes of thoracic endovascular aortic repair with open concomitant cervical debranching

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) has become the most common surgical procedure for treatment of descending thoracic aortic pathology. Cervical debranching in the form of carotid-subclavian bypass or transposition (CSBT) and carotid-carotid bypass (CCB) has enabled the use of TEVAR for the treatment of more complex anatomy involving the arch. The present study examined the effects of concomitant cervical bypass on the perioperative outcomes of TEVAR.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program files (2005-2017) were reviewed. Using the Current Procedural Terminology codes, all patients who had undergone TEVAR were identified and were divided into three groups: TEVAR, TEVAR with one bypass (CSBT or CCB), and TEVAR with two bypasses (CSBT and CCB). The patient characteristics and perioperative outcomes of the three groups were compared. Multivariable analysis was performed to determine the factors associated with mortality.

RESULTS

A total of 3281 patients had undergone TEVAR and 10% had also undergone one or more debranching procedure (one bypass, 9%; two bypasses, 1%). The frequency of debranching had increased from 3.4% to 10.9% (P = .01) during the study period. Significant differences were found among the three groups in age, sex, smoking history, urgency of surgery, and anesthesia technique. The patients who had undergone TEVAR with cervical debranching had had significantly greater morbidity, longer operating times, and longer hospital stays compared with those who had undergone TEVAR alone. The mortality of TEVAR with two bypasses (22.6%) was significantly greater than that of TEVAR alone (7.5%) and TEVAR with one bypass (6.8%; P < .01). The total morbidity (30.9% vs 35.1% vs 67.7%; P < .001) and stroke rate (3% vs 7.5% vs 12.9%; P < .0001) increased with the increasing number of bypasses. A subgroup analysis of patients who had undergone TEVAR with one bypass showed no significant differences in mortality between TEVAR plus CSBT (6.6%) vs TEVAR plus CCB (8.8%; P = .63). Multivariable analysis showed that TEVAR with two bypasses was associated with significantly increased mortality compared with TEVAR alone (odds ratio [OR], 4.33; 95% confidence interval [CI], 1.75-10.73) and TEVAR with one bypass (OR, 3.44; 95% CI, 1.24-9.51). Older age (OR, 1.74; 95% CI, 1.42-2.13), dependent functional status (OR, 1.48; 1.00-2.19), dialysis (OR, 2.61; 95% CI, 1.57-4.33), and emergent status (OR, 3.66; 95% CI, 2.73-4.90) were also associated with mortality.

CONCLUSIONS

TEVAR with concomitant cervical debranching has been increasingly used to treat complex aortic pathology but is associated with significantly worse outcomes than TEVAR alone. As advanced endovascular technology to treat the aortic arch emerges, the outcomes of open surgical debranching in the present study constitute an important benchmark for comparison.

Experimental Analysis of the Quality of Needle-Assisted Fenestration in Aortic Stent-Grafts and the Differences Between Gradual and Rapid Balloon Dilation

Purpose: To report the findings of an in vitro experiment to evaluate the quality of needle fenestrations dilated by different size balloons in various stent-grafts and to investigate the differences between gradual and rapid dilation. Materials and Methods: Fenestrations were made using an 18-G needle in 5 different polyester or expanded polytetrafluoroethylene (ePTFE) stent-grafts: Relay, Valiant, Hercules, TAG, and Ankura. Each stent-graft received 2 groups of fenestrations: one was followed by gradual sequential dilation (4-, 6-, 8-, and 10-mm balloons) and the other by rapid dilation (4- and 10-mm balloons). The pressure was increased to 10 atmospheres or until the balloon was fully inflated with no waist. Quantitative and qualitative evaluations, including fenestration diameter, area, shape, and margins were conducted using light microscopy and scanning electron microscopy. Results: Relay had the strongest resistance to dilation and Ankura the slightest. The maximum length and area of holes expanded as the balloon diameter increased. The fenestrations in polyester devices were mostly elliptical or slit-like, with limited tears but extensive fibers visible in the margin, while ePTFE stent-grafts showed larger fenestration areas with clearer margins. Ankura showed the best quality of fenestrations, which were always circular or square without fabric tears, while the holes in the TAG were square or elliptical but sometimes had a slit after large balloon dilation (≥6 mm). The Relay, Valiant, Hercules, and Ankura devices showed no difference in maximum diameter, fenestration area, or scores of shape and margin (p>0.05). Rapid dilation in the TAG increased the rate of uncontrolled fabric tear, resulting in a larger final diameter (12.90 vs 10.82 mm, p=0.047), smaller area (30.46 vs 41.09 mm2, p=0.028), worse shape (0.75 vs 1.20, p=0.268), and worse margin (0.40 vs 1.00, p=0.174). Though the decreased fenestration shape and margin scores did not reach statistical significance, the trend for decline was more obvious than with the other devices. Conclusion: Materials and structures of the stent-grafts determine the quality of fenestrations dilated by different size balloons. The use of sequential vs rapid balloon dilation is also crucial for fashioning high-quality fenestrations and should be selected judiciously.

Art of operative techniques: treatment options in arch penetrating aortic ulcer

Penetrating aortic ulcer (PAU) of the arch has a focal extent which often represents an adequate anatomic target for thoracic endovascular aortic repair (TEVAR). However, the anatomic constraints represented by the supra-aortic vessels pose either clinical or technical challenges that increase when the PAU develops proximally in the arch. Currently, different types of endografts are commercially available and have been used to treat aortic arch lesions. These include branched/fenestrated endografts for a total endovascular approach, and standard devices that can be used in combination with open/hybrid surgical operations, with the aim to exploit the minimally invasive nature of TEVAR by extending the proximal landing zone when necessary. We describe several current techniques adopted in such settings.

Closing the gap between type A and type B aortic dissections

PURPOSE OF REVIEW

Given its rarity little is known about natural history, surgical indications, and results of acute non-A non-B dissections. With this review, we aim to review the current knowledge of this subject.

RECENT FINDINGS

non-A non-B aortic dissections should be differentiated from type B aortic dissections. A strikingly high proportion of these patients have a complicate course requiring treatment and the mortality of patients treated with medical therapy is substantially higher compared to type B dissections. Surgical and endovascular treatment can be accomplished safety, with very good results in terms of mortality and morbidity also in the acute setting. Several treatments options are available including endovascular repair with thoracic endovascular aortic repair (TEVAR) associated with Chimney grafts or carotid to subclavian by pass, open arch replacement mainly by means of the frozen elephant trunk technique and hybrid arch repair with debranching of the supra-aortic vessel and zone 0 TEVAR.

SUMMARY

considering the high rate of complication, the high mortality of patients managed medically and the safety of surgical and endovascular repair, early invasive treatment of non-A non-B dissections may be further considered. The treatment should be tailored to the morphology of the dissected aorta with TEVAR reserved to more distal lesions and open arch replacement with the FET technique for more proximal lesions.

Volume-Outcome Relationships in Surgical and Endovascular Repair of Aortic Dissection

BACKGROUND

As surgical mortality decreases and endovascular utilization increases, it is unknown whether volume-outcome relationships exist in thoracic aortic dissection repair. We characterized volume-outcome relationships for surgical and endovascular management of thoracic aortic dissection.

METHODS

Patients aged more than 18 years undergoing repair of thoracic aortic dissection in the United States between 2010 and 2014 were identified in seven all-payer state inpatient administrative databases. Patients were divided into groups based on type of repair: surgical repair of type A dissection (TAAD), surgical repair of type B dissection (TBAD), and endovascular repair (TEVAR). Hierarchical logistic regression models evaluated the association between hospital volume and in-hospital mortality.

RESULTS

Overall in-hospital mortality rate was 13.4% (890 of 6650), highest after TAAD (463 of 2918, 15.9%), followed by TBAD (270 of 1934, 14.0%) and TEVAR (157 of 1798, 8.7%). Volume-outcome relationships for adjusted in-hospital mortality were demonstrated for TAAD and TBAD (P-trend < .001), but not TEVAR (P-trend = .11). Adjusted in-hospital mortality differed most for TAAD (fewer than 3 cases per year: 21%, 95% confidence interval, 18% to 24%; vs 11 or more cases per year: 12%, 95% confidence interval, 8% to 16%; P < .001) and TBAD (fewer than 2 cases per year: 18%, 95% confidence interval, 15% to 22%; vs 11 or more cases per year: 9%, 95% confidence interval, 5% to 12%; P < .001), whereas TEVAR did not differ between quartiles. Adjusted mortality was lower at centers with 26 or more overall annual thoracic dissection repairs, compared with any of the three lower-volume quartiles (P < .001).

CONCLUSIONS

This study demonstrated lower mortality at high-volume hospitals for overall repair of aortic dissection, persisting separately for surgical repair of TAAD and TBAD, but not TEVAR. As endovascular technology advances and practice patterns consequently change, analyses should focus on understanding the balance between procedural volume, mortality, and access to care for thoracic aortic dissection.