Long-term outcomes of frozen elephant trunk for aortic dissection: a single-center experience.

BACKGROUND: To date a number of papers analysing outcomes of the frozen elephant trunk (FET) in acute aortic dissection has been published. However, there are limited comparative studies on long-term outcomes of FET in acute and chronic aortic dissection. The objective of the study was to analyze the long-term outcomes after FET procedure for aortic dissection (AD). METHODS: Between March 2012 and December 2022, a total of 123 FET had been performed for thoracic aortic disease. Patients with aortic dissection (n = 97) were divided into 2 groups: acute (n = 32, 33%) and chronic aortic dissection (n = 65, 67%). Pre-, intra- and postoperative data were retrospectively collected from electronic patient's records, including follow-up data of the analyzed patients. RESULTS: The incidence of stroke was 3.1%. The delirium rate was up to 9.3% in both groups with a prevalence in chronic aortic dissection (CAD) group without significant differences (P = 0.494). Paraplegia was diagnosed only in CAD patients (n = 2). Respiratory failure and the rate of renal replacement therapy were similar in the studied groups. Re-sternotomy was required in one (3.1%) patient with acute AD and 5 (7.7%) patients with chronic AD (P = 0.416). Overall 30-day mortality in the entire cohort, acute and chronic AD was 13 (13.4%), 7 (21.9%) and 6 (9.2%), respectively (P = 0.097). The overall survival rate at 60 months for the entire cohort, acute and chronic AD was 64.1 ± 5.9%, 62.3 ± 9.1%, 66.5 ± 7%, respectively (P = 0.265). Freedom from unintended distal aortic re-intervention at 60 months for the entire cohort of patients, acute and chronic AD was 74.2 ± 1.5%, 100%, 65.3 ± 2%, respectively (P = 0.355). CONCLUSIONS: Our experience showed acceptable long-term outcomes after the FET procedure including mortality and re-intervention rate in patients with aortic dissection regardless of acuity of the dissection. TRIAL REGISTRATION: The study has been registered in Australian and New Zealand Clinical Trial Registry (ACTRN 12618001329257) on August 7, 2018.

Analysis of antibiotic strategies to prevent vascular graft or endograft infection after surgical treatment for infective native aortic aneurysms: a systematic review.

INTRODUCTION: Some patients with an infective native aortic aneurysm (INAA) develop an aortic vascular graft or endograft infection (VGEI) even after successful open surgical repair or endovascular intervention. The aim of the systematic review and meta-analysis performed herein was to compare the clinical outcomes of different surgical and antibiotic treatment strategies. METHODS: We systematically searched PubMed, MEDLINE, EMBASE and Web of Science. The keywords used for the search were "mycotic aortic aneurysm", "infected aortic aneurysm", "infective native aortic aneurysm", "antibiotics", "surgery", and "endovascular". The search was limited to articles written in English and to studies involving humans. Articles published before 2000 were excluded. Case reports and review articles were excluded. RESULTS: Of the 524 studies retrieved from our search of the databases, 47 articles were included in this study. Among the 47 articles (1546 patients, 72.8% of whom were male) retrieved, five articles were excluded from the subgroup analysis because the data concerning open surgical repair and endovascular intervention could not be separated. The remaining 42 articles included a total of 1179 patients who underwent open surgical repair (622 patients) or endovascular intervention (557 patients) for INAA. There was a statistically significant difference (p = 0.001) in the pooled in-hospital mortality rate between the open surgical repair group (13.2%, 82/622) and the endovascular intervention group (7.2%, 40/557). However, there was a statistically significant difference (p < 0.001) in the aortic VGEI rate between the open surgical repair group (5.4%). 29/540) and endovascular intervention (13.3%, 69/517) group. For patients who underwent open surgical repair, a lower rate of aortic vascular graft infection was associated with long-term antibiotic use (p = 0.005). For patients who underwent endovascular intervention, there was a trend of association (p = 0.071) between the lower rate of aortic endograft infection and lifelong antibiotic use. CONCLUSION: Infective native aortic aneurysms are life-threatening. The pooled in-hospital mortality rate of the open surgical repair group was significantly higher than that of the endovascular intervention group, whereas the rate of the aortic VGEI in the open surgical repair group was significantly lower than that in the endovascular intervention group. Regardless of whether open surgical repair or endovascular intervention is performed, better long-term outcomes can be achieved with aggressive antibiotic treatment, which is especially important for patients who undergo endovascular intervention.

Tailoring silk-based covering material with matched mechanical properties for vascular tissue engineering.

Vascular covered stents play a significant therapeutic role in cardiovascular diseases. However, the poor compliance and biological inertness of commercial materials cause post-implantation complications. Silk fibroin (SF), as a biomaterial, possesses satisfactory hemocompatibility and tissue compatibility. In this study, we developed a silk film for use in covered stents by employing a layer-by-layer self-assembly strategy with regenerated SF on silk braiding fabric. We investigated the effects on the mechanical properties of the silk films in detail, which were closely correlated with fabric parameters and layer-by-layer self-assembly. The results showed that there was a significant relationship between these factors and both the compliance and mechanical strength. The 1 × 2/90°/100/SF6 film exhibited excellent mechanical properties. Notably, compliance reached 2.6%/100 mmHg, matching that of the human saphenous vein. Thus, this strategy shows promise in developing a novel covered stent, with biocompatible and comprehensive mechanical properties, and significant potential for clinical applications.

Segmental histomorphometry of the porcine ureter for use as a vascular xenograft.

PURPOSE: To histologically quantify the different tissues that make up the porcine ureter, (epithelial, connective, and muscular tissue) in the three segments labelled: cranial, middle and caudal, in order to identify the segment most compatible for use as a vascular graft. METHODS: Fifteen porcine ureters were collected, divided into the three segments, and the samples were stained with hematoxylin and eosin, picrosirius red and Weigert's resorcin-fuchsin. The immunohistochemistry technique was applied for alpha-smooth muscle actin. Collagen fibers, muscle, epithelium, and elastic fibers tissue were quantified, in the entire ureter, and divided into hemispheres, comparing the different segments. RESULTS: When comparing hemisphere segments, significant differences were observed (p < 0.01) for collagen and muscle tissue, with the cranial segment presenting the greatest amount of these components when compared to the middle and caudal. No significant difference was observed between the segments when comparing the entire ureters. CONCLUSIONS: After comparing the segments by hemisphere, the cranial segment presented a slight advantage for use as a vascular graft due to presenting greater collagen fiber content.

[3D bioprinting: classification, evaluation, and application in vascular tissue engineering].

Cardiovascular diseases are major diseases, and there is lack of artificial blood vessels with small diameters which can be applied in coronary artery bypass surgery. The conventional vascular scaffold preparation techniques in tissue engineering have shortcomings in regulating the diameter, geometric shape, and interconnectivity of the scaffold. 3D bioprinting can simulate the natural structure of the vascular tissue, accurately print live cells and biomaterials, and regulate the microstructure and porosity of scaffolds on the nanoscale, providing new ideas for vascular tissue engineering. This article systematically evaluates the classification of 3D bioprinting technologies and reviews the latest research progress of 3D bioprinting in vascular tissue engineering. It summarizes the advantages of 3D bioprinting and points out the problems that need to be solved, such as the immune rejection of blood vessel materials, providing reference for the further research.

Evaluation of properties for Carbothane™ 3575A-based electrospun vascular graftsin vitroandin vivo.

Bioengineered vascular grafts (VGs) have emerged as a promising alternative to the treatment of damaged or occlusive vessels. It is thought that polyurethane (PU)-based scaffolds possess suitable hemocompatibility and biomechanics comparable to those of normal blood vessels. In this study, we investigated the properties of electrospun scaffolds comprising various blends of biostable polycarbonate-based PU (Carbothane™ 3575A) and gelatin. Scaffolds were characterized by scanning electron microscopy, infra-red spectroscopy, small-angle x-ray scattering, stress-loading tests, and interactions with primary human cells and blood. Data fromin vitroexperiments demonstrated that a scaffold produced from a blend of 5% Carbothane™ 3575A and 10% gelatin has proven to be a suitable material for fabricating a small-diameter VG. A comparativein vivostudy of such VGs and expanded polytetrafluoroethylene (ePTFE) grafts implanted in the abdominal aorta of Wistar rats was performed. The data of intravital study and histological examination indicated that Carbothane-based electrospun grafts outclass ePTFE grafts and represent a promising device for preclinical studies to satisfy vascular surgery needs.

Digital twin and artificial intelligence technologies for predictive planning of endovascular procedures.

Current planning of aortic and peripheral endovascular procedures is based largely on manual measurements performed from the 3-dimensional reconstruction of preoperative computed tomography scans. Assessment of device behavior inside patient anatomy is often difficult, and available tools, such as 3-dimensional-printed models, have several limitations. Digital twin (DT) technology has been used successfully in automotive and aerospace industries and applied recently to endovascular aortic aneurysm repair. Artificial intelligence allows the treatment of large amounts of data, and its use in medicine is increasing rapidly. The aim of this review was to present the current status of DTs combined with artificial intelligence for planning endovascular procedures. Patient-specific DTs of the aorta are generated from preoperative computed tomography and integrate aorta mechanical properties using finite element analysis. The same methodology is used to generate 3-dimensional models of aortic stent-grafts and simulate their deployment. Post processing of DT models is then performed to generate multiple parameters related to stent-graft oversizing and apposition. Machine learning algorithms allow parameters to be computed into a synthetic index to predict Type 1A endoleak risk. Other planning and sizing applications include custom-made fenestrated and branched stent-grafts for complex aneurysms. DT technology is also being investigated for planning peripheral endovascular procedures, such as carotid artery stenting. DT provides detailed information on endovascular device behavior. Analysis of DT-derived parameters with machine learning algorithms may improve accuracy in predicting complications, such as Type 1A endoleaks.

3D-Printed Hydrogels with Engineered Nanocrystalline Domains as Functional Vascular Constructs.

Three-dimensionally printed (3DP) hydrogel-based vascular constructs have been investigated in response to the impaired function of blood vessels or organs by replicating exactly the 3D structural geometry to approach their function. However, they are still challenged by their intrinsic brittleness, which could not sustain the suture piercing and enable the long-term structural and functional stability during the direct contact with blood. Here, we reported the high-fidelity digital light processing (DLP) 3D printing of hydrogel-based vascular constructs from poly(vinyl alcohol)-based inks, followed by mechanical strengthening through engineering the nanocrystalline domains and subsequent surface modification. The as-prepared high-precision hydrogel vascular constructs were imparted with highly desirable mechanical robustness, suture tolerance, swelling resistance, antithrombosis, and long-term patency. Notably, the hydrogel-based bionic vein grafts, with precise valve structures, exhibited excellent control over the unidirectional flow and successfully fulfilled the biological functionalities and patency during a 4-week implantation within the deep veins of beagles, thus corroborating the promising potential for treating chronic venous insufficiency.

Surgical treatment of graft infection combined with aortoesophageal fistula after TEVAR: a retrospective single-center, single-arm study.

OBJECTIVE: Aortoesophageal fistula (AEF) secondary to thoracic aortic endovascular repair (TEVAR) is rare and fatal. The author reports the treatment methods and outcomes of 10 patients with a TEVAR graft infection and an aortoesophageal fistula. METHOD: A retrospective analysis was conducted on the clinical data of 10 patients who developed a secondary AEF and a graft infection after TEVAR from March 2018 to March 2024. RESULT: The perioperative mortality rate was 70%. Two patients had TEVAR only and all died of bleeding and infection. Eight patients underwent open surgery, five died within 30 days, four of them died due to massive bleeding, the one patient died of a serious infection after surgery. Three patients recovered well and were discharged. One patient died of severe pneumonia 3 months after discharge, and two patients survived for 6 years and 3 months, respectively. CONCLUSION: Extra-anatomical bypass reconstruction is feasible for treating graft infection combined with aortoesophageal fistula after TEVAR but related to bad outcomes in most of the patients. It is reserved for highly select patients and is performed at centers with experience with this procedure.

Fenestrated and Branched Endovascular Aortic Aneurysm Repair for Treating Juxtarenal Aneurysms: An Update.

Fenestrated and branched endovascular aortic aneurysm repair (f-EVAR, b-EVAR, respectively) are technically challenging procedures that have evolved over the last decade for complex aortic aneurysms. They are alternatives to surgical repair for suprarenal and juxtarenal aortic aneurysms. A Pubmed database was reviewed by searching keywords related to f-EVAR, b-EVAR, and juxta renal abdominal aortic aneurysm (AAA) from the last five years to see current indications, contemporary techniques, and results of these techniques for juxtarenal aneurysms. Over the years, f-EVAR and b-EVAR have improved, with high technical success (>95%) and mortality rates of 1-5% for pararenal and 5-10% for thoracoabdominal aortic aneurysms. Key Words: Fenestrated-branched endovascular repair, Fenestrated EVAR, Branched EVAR, Juxtarenal aortic aneurysm.

Single-branched stent-graft with on-table fenestration for the management of zone 2 landing TEVAR with an isolated left vertebral artery: a pilot study.

BACKGROUND: It is challenging to simultaneously conduct total endovascular repair and reconstruct the left subclavian artery (LSA) and isolated left vertebral artery (ILVA) in patients who had an ILVA and required zone 2 anchoring. This pilot study reported the initial application experience of thoracic endovascular aortic repair (TEVAR) with a proximal zone 2 landing for aortic arch reconstruction in patients with ILVA. METHODS: This study was a retrospective consecutive single-center case series analysis, which involved four patients with ILVA who required zone 2 anchoring and received TEVAR combined with a single-branched stent graft and concomitant on-table fenestration between March 2021 and December 2022. RESULTS: The postoperative follow-up period was 6-27 months, and no postoperative deaths or other primary complications occurred. There were no signs of a stroke or spinal cord ischemia, as well as no chest or back pain. The postoperative computed tomography angiography showed unobstructed ILVA and LSA, no stent stenosis and displacement, and no signs of endoleak. CONCLUSION: The outcome suggested that this technique might be a feasible, safe, and alternative treatment for such patients. Further studies with larger samples and longer follow-up periods are needed to confirm our findings.

Off-pump ascending aorta-abdominal aorta bypass in patient with endoleak.

Thoracic endovascular aortic repair is commonly used in the surgical treatment of patients with aortic coarctation, but complications such as endoleaks can occur. This video tutorial presents a case study involving the exclusion of a stent graft from the bloodstream through total transection of the aortic arch and abdominal aorta, with off-pump aortic grafting and debranching of the left carotid and subclavian arteries.

Total aortic arch replacement with frozen elephant trunk technique for intramural haematoma of the thoracic aorta.

Presenting this video tutorial, we want to demonstrate a step-by-step surgical approach to acute intramural haematoma of the thoracic aorta without a definite entry tear. Limited by the aortic valve proximally, the intramural haematoma involved the aortic root, ascending aorta, aortic arch, including adjacent parts of supra-aortic branches, and descending aorta extending to the diaphragmatic level. The operative strategy involved urgent total aortic arch replacement with the frozen elephant trunk technique and anatomical reimplantation of the three supra-aortic vessels. The direct open over-the-wire technique was used to cannulate the right axillary artery, and standard venous cannulation was performed while brain protection was achieved with bilateral selective antegrade cerebral perfusion.

3-Dimensional printing in vascular disease: From manufacturer to clinical use.

Three-dimensional (3D) printing has been used in medicine with applications in many different fields. 3D printing allows patient education, interventionalists training, preprocedural planning, and assists the interventionalist to improve treatment outcomes. 3D printing represents a potential advancement by allowing the printing of flexible vascular models. In this article, the authors report a clinical case using 3D printing to perform a physician-modified fenestrated endograft. An overview of 3D printing in vascular and endovascular surgery is provided, focusing on its potential applications for training, education, preprocedural planning, and current clinical applications.

Fabrication of small-diameter in situ tissue engineered vascular grafts with core/shell fibrous structure and a one-year evaluation via rat abdominal vessel replacement model.

A high vascular patency was realized in the bulk or surface heparinized small-diameter in situ tissue-engineered vascular grafts (TEVGs) via a rabbit carotid artery replacement model in our previous studies. Those surface heparinized TEVGs could reduce the occurrence of aneurysms, but with a low level of the remodeled elastin, whereas those bulk heparinized TEVGs displayed a faster degradation and an increasing occurrence of aneurysms, but with a high level of the regenerated elastin. To combine the advantages of the bulk and surface graft heparinization to boost the remodeling of elastin and defer the occurrence of aneurysms, a coaxial electro-spinning technique was used to fabricate a kind of small-diameter core/shell fibrous structural in situ TEVGs with a faster degradable poly(lactic-co-glycolic acid) (PLGA) as a core layer and a relatively lower degradable poly(ε-caprolactone) (PCL) as a shell layer followed by the surface heparinization. The in vitro mechanical performance and enzymatic degradation tests revealed the resulting PLGA@PCL-Hep in situ TEVGs possessing not only a faster degradation rate, but also the mechanical properties comparable to those of human saphenous veins. After implanted in the rat abdominal aorta for 12 months, the good endothelialization, low inflammation, and no calcification were evidenced. Furthermore, the neointima layer of regenerated new blood vessels was basically constructed with a well-organized arrangement of elastin and collagen proteins. The results showed the great potential of these in situ TEVGs to be used as a novel type of long-term small-diameter vascular grafts.

Non-circulatory arrest aortic arch replacement.

The definitive management of combined aortic arch and descending aortic pathologies such as aneurysms and dissections is either a single or staged operation associated with high morbidity and mortality. Stroke, kidney dysfunction, coagulopathy and high blood transfusion requirements are all affiliated with hypothermic circulatory arrest and prolonged cardiopulmonary bypass times. Considering the perilous nature of these operations, the authors describe a step-by-step zone 2 arch replacement as a staged frozen elephant trunk procedure, which provides an adequate landing zone for a later-placed endovascular stent yet maintains a short cardiopulmonary bypass time and no circulatory arrest.

Endograft Collapse after Standard Endovascular Aneurysm Repair Implantation: A Report of Two Cases.

Endovascular aneurysm repair (EVAR) has emerged as the preferred treatment for abdominal aortic aneurysm (AAA), offering advantages such as reduced mortality, faster recovery, and fewer complications compared to open repair (OR). However, concerns persist regarding long-term durability, and the need for reinterventions. Among all reported EVAR complications, endograft collapse poses a significant challenge, particularly when presenting with acute lower limb ischemia (ALI). The aim of this report is to describe two cases of non-dissection-related abdominal endograft collapse manifesting as ALI, requiring urgent intervention, emergent conversion to OR and complete endograft removal.

In Situ Needle Fenestration during Thoracic Endovascular Aneurysm Repair: Successful Fenestration of Two Overlapping Thoracic Stent Grafts.

Endovascular stent grafting is becoming more common in treating complex thoracic aortic aneurysms and dissections. When it becomes necessary to cover the supra-aortic vessels, maintaining blood supply through the supra-aortic branches can be achieved by performing in situ needle fenestration. We present a case of a 65-year-old man with a type B aortic dissection that extended from the origin of the left subclavian artery. A stent graft was inserted into the thoracic aorta distally of the origin of the left common carotid artery. Due to the stent graft moving distally and not adequately sealing the subclavian artery, a second stent graft was placed more proximally. Both stent grafts were successfully in situ fenestrated using a needle, and a stent graft was inserted into the subclavian artery. In conclusion, during thoracic endovascular aortic repair, in situ needle fenestration can be successfully carried out on two overlapping thoracic stent grafts.