Native Artery Research Articles

Human acellular amniotic membrane/polycaprolactone vascular grafts prepared by electrospinning enable vascular remodeling in vivo

BackgroundVascular transplantation is an effective treatment for severe vascular lesions. The design of the bioactive and mechanical properties of small-caliber vascular grafts is critical for their application in tissue engineering. In this study, we sought to develope a small-caliber vascular graft by electrospinning a mixture of a human acellular amniotic membrane (HAAM) and polycaprolactone (PCL).ResultsMechanical tests showed that the vascular grafts were strong enough to endure stress from adjacent blood vessels and blood pressure. The biocompatibility of the HAAM/PCL vascular grafts was evaluated based on cell proliferation in vitro. The tubular formation test demonstrated that vascular grafts containing HAAM could improve human umbilical vein endothelial cell function, and in vivo implantation was performed by replacing the rat abdominal aorta. The HAAM/PCL vascular graft was found to promote attachment and endothelial cell retention. The regenerated smooth muscle layer was similar to native arteries' smooth muscle layer and the endothelium coverage was complete.ConclusionsThese results suggest that our constructs may be promising vascular graft candidates and can potentially be used to develop vascular grafts that can endothelialize rapidly in vivo.

3D Coaxial Printing of Small‐Diameter Artificial Arteries

As a treatment for the widely spread cardiovascular diseases (CVD), bypass vascular grafts have room for improvement in terms of mechanical property match with native arteries. A 3D‐printed nozzle is presented, featuring unique internal structures, to extrude artificial vascular grafts with a flower‐mimicking geometry. The multilayer‐structured graft wall allows the inner and outer layers to interfere sequentially during lateral expansion, replicating the nonlinear elasticity of native vessels. Both experiment and simulation results verify the necessity and benefit of the flower‐mimicking structure in obtaining the self‐toughening behavior. The gelation study of natural polymers and the utilization of sacrificial phase enables the smooth extrusion of the multiphase conduit, where computer‐assisted image analysis is employed to quantify manufacturing fidelity. The cell viability tests demonstrate the cytocompatibility of the gelatin methacryloyl (GelMA)/sodium alginate grafts, suggesting potential for further clinical research with further developments. This study presents a feasible approach for fabricating bypass vascular grafts and inspires future treatments for CVD.

Renal Artery Blood Flow and Surface Parenchymal Perfusion During Renal Artery Endoshunting in a Porcine Model

ObjectiveIschaemia and reperfusion can result in permanent tissue damage. During complex open abdominal aortic surgery, transient clamping of renovisceral arteries may be required to successfully complete the vascular repair. Endovascular shunting (endoshunting) presents an alternative technique for managing such temporary renovisceral ischaemia. This study aimed to investigate the performance of endoshunting to the renal circulation in a porcine model. MethodsThis study of five domestic pigs investigated arterial volume flow rates during endoshunting of a single renal artery and the associated impact on renal perfusion parameters (laser Doppler renal parenchymal perfusion, renal oxygen extraction, and selective urinary output). The study was performed in three steps: baseline registrations (30 minutes), endoshunting (120 minutes), and restitution (60 minutes). The right kidney was used as the experimental side and the left kidney as control. ResultsThe median arterial flow rate in the left control kidney remained constant throughout the experiment. On the right (endoshunted) side, the baseline median arterial flow rate was 267 (range, 160 – 404) mL/min. Following activation of the endoshunt, the median arterial volume flow dropped by 59% to 110 (range, 45 – 150) mL/min (p = .018). During endoshunting, the median kidney surface perfusion decreased to 42% of the baseline value. On the control side, a rise in the median parenchymal perfusion was observed after endoshunt activation, which was again normalised following restitution of native right renal artery flow. During endoshunting, the median regional urine production was 0.32 (range, 0.12 – 0.50) mL/hour but resumed after renal artery flow restitution. ConclusionOn average, the endoshunted kidneys showed a rapid restoration of blood flow, parenchymal perfusion, and urine production after 120 minutes of endoshunting. This suggests that endoshunting to the kidney using an endoshunt system might be a promising strategy to preserve renal function when a temporary interruption of native renal artery blood flow is needed during complex vascular surgical repairs involving the renal arteries.

A Computational Framework to Optimize the Mechanical Behavior of Synthetic Vascular Grafts.

The failure of synthetic small-diameter vascular grafts has been attributed to a mismatch in the compliance between the graft and native artery, driving mechanisms that promote thrombosis and neointimal hyperplasia. Additionally, the buckling of grafts results in large deformations that can lead to device failure. Although design features can be added to lessen the buckling potential, the addition is detrimental to decreasing compliance (e.g., reinforcing coil). Herein, we developed a novel finite element framework to inform vascular graft design by evaluating compliance and resistance to buckling. A batch-processing scheme iterated across the multi-dimensional design parameter space, which included three parameters: coil thickness, modulus, and spacing. Three types of finite element models were created in FEBio for each unique coil-reinforced graft parameter combination to simulate pressurization, axial buckling, and bent buckling, and results were analyzed to quantify compliance, buckling load, and kink radius, respectively, from each model. Importantly, model validation demonstrated that model predictions agree qualitatively and quantitatively with experimental observations. Subsequently, data for each design parameter combination were integrated into an optimization function for which a minimum value was sought. The optimization values identified various candidate graft designs with promising mechanical properties. Our investigation successfully demonstrated the model-directed framework identified vascular graft designs with optimal mechanical properties, which can potentially improve clinical outcomes by addressing device failure. In addition, the presented computational framework promotes model-directed device design for a broad range of biomaterial and regenerative medicine strategies.

Competitive flow of bilateral internal thoracic artery Y-graft: Insights from hemodynamics and transit time flow measurement parameters

Recent studies have demonstrated the superior efficacy of bilateral internal thoracic artery (BITA) grafts compared to other graft methods in treating coronary artery disease. Competitive flow (CF) is a primary factor contributing to graft failure in the long term. For the first time, the CF of the BITA-Y graft has undergone rigorous numerical analysis. Through the application of transit time flow measurement (TTFM) and hemodynamic parameters, this study provides a new perspective on graft performance. Simulation results indicate that average flow, TTFM, and hemodynamic parameters fall within the critical range for stenosis severities below 90%. Specifically, at 80% stenosis, the mean graft flow (MGF) and pulsatility index (PI) of the left internal thoracic artery (LITA) were 0.071 cc/s and 27, respectively, while those of the right internal thoracic artery (RITA) were 0.211 cc/s and 11. With increasing stenosis severity, TTFM parameters remained within the clinical permissible limit (MGF > 0.34 cc/s and PI < 5). At 95% stenosis severity, the MGF and PI for LITA were 0.526 cc/s and 1.2, respectively, while those for RITA were 0.790 cc/s and 0.9. The results indicate the presence of competitive flow within the BITA-Y graft for stenosis severities below 90% area reduction, suggesting a potential risk of graft failure in the long term. Additionally, the results indicated that when there are significant differences in stenosis severity between the two native arteries, the BITA-Y graft is not optimal due to CF, characterized by low MGF and high reverse flow.

Стентування відкритої протоки як перший етап хірургічного лікування тетради Фалло з незливними гілками легеневої артерії

The aim – to show the results of patent ductus arteriosus (PDA) stenting as the first stage of palliative treatment in patients with tetralogy of Fallot with non-confluent branches of the pulmonary artery.Materials and methods. This retrospective, single-center study included 10 consecutive patients who underwent PDA stenting since 2013 to 2023. The average age at the time of surgery was 96.00 ± 82.92 days (range 4 to 411 days), the average weight was 5.10 ± 1.78 kg (range 2.8 to 11 kg). The arterial oxygen saturation level (SaO2) before the intervention was 72.0 ± 6.7 % (range 60 to 87 %).Results. There were no intraoperative complications in all patients of this group. The length of the stay in the intensive care unit after surgery was 5.00 ± 1.36 days. SaO2 level increased to 89.00 ± 4.08 %. The duration of artificial lung ventilation after surgery was 36.5 ± 18.00 hours, and the duration of inotropic support was 81.1 ± 33.8 hours. In the long term, all patients showed significant growth of the native pulmonary artery branches. All patients of this group achieved total repair of this pathology after 192.00 ± 60.28 days, on average. At the moment of total repair, the size of the left branch of the pulmonary artery increased from 3.9 ± 0.8 mm to 7.8 ± 1.6 mm, and the right branch increased from 5.8 ± 1.2 mm to 7.70 ± 1.04 mm; the Nakata index increased from 133.0 ± 29.1 mm2/m2 to 241.2 ± 97.8 mm2/m2; end-diastolic index of the left ventricle increased from 31.4 ± 10.8 ml/m2 to 43.1 ± 11.4 ml/m2.Conclusion. PDA stenting in patients with tetralogy of Fallot combined with non-confluent branches of the pulmonary artery is an effective palliative procedure. This method allows to postpone the total repair to an older age, ensures sufficient and symmetric growth of the branches of pulmonary artery, and helps to avoid risks associated with repeat open heart surgeries.

Influence of different pressure regimes on the properties of an engineered small-diameter vascular scaffold tested in a custom-made bioreactor.

Vascular tissue engineering endeavors to design, fabricate, and validate biodegradable and bioabsorbable small-diameter vascular scaffolds engineered with bioactive molecules, capable of meeting the challenges imposed by commercial vascular prostheses. A comprehensive investigation of these engineered scaffolds in bioreactor is deemed essential as a prerequisite before any in vivo experimentation in order to get information regarding their behavior under physiological conditions and predict the biological activities they will possess. This study focuses on an innovative electrospun scaffold made of poly(caprolactone) and poly(glycerol sebacate), integrating quercetin, able to modulate inflammation, and gelatin, necessary to reduce permeability. A custom-made bioreactor was used to assess the performances of the scaffolds maintained under different pressure regimes, covering the human physiological pressure range. As results, the 3D microfibrous architecture was notably influenced by the release of bioactives, maintaining the adequate properties needed for the in vivo regeneration and scaffolds showed mechanical properties similar to human native artery. Release of gelatin was adequate to avoid blood leakage and useful to make the material porous during the testing period, whereas the amount of released quercetin was useful to counteract the post-surgery inflammation. This study showcases the successful validation of an engineered scaffold in a bioreactor, enabling to consider it as a promising candidate for vascular substitutes in in vivo applications. Our approach represents a significant leap forward in the field of vascular tissue engineering, offering a multifaceted solution to the complex challenges associated with small-diameter vascular prostheses.&#xD.

A retrospective study: Long term prognosis in adults with PA-VSD-MAPCAs

BackgroundPulmonary Atresia, Ventricular Deptal Defect, and Major Aortopulmonary Collateral Arteries (PA-VSD-MAPCAs) is a congenital cyanotic heart defect with poor prognosis. Due to its complex and highly variable anatomy, the best treatment plan is not clear. We aimed (1) to investigate the survival of PA-VSD-MAPCAs patients according to the underlying original anatomy and treatment strategy, and (2) to evaluate life expectancy between patients with or without severe hypoplastic native pulmonary arteries (NPAs) after surgical versus non-surgical treatment. MethodsA prospectively established database of 169 PA-VSD-MAPCAs patients treated and followed up at University Hospitals Leuven was accessed. Patients were divided into three groups according to the treatment strategy. Kaplan-Meier survival curves were plotted, and Log Rank tests were used for comparison. ResultsThe overall mean survival for patients with PA-VSD-MAPCAs was 38.5 years (95%-CI: 33.1–43.9). Patients with complete intracardiac repair had the longest mean survival of 43.8 years (95%-CI: 38.1–49.6) versus the other groups (p < 0.001). A longer mean event-free survival time was found in patients with normal, well-developed NPAs (p = 0.047). Finally, patients with poorly developed or absent NPAs had worse survival rates when a surgical approach was followed. Systemic-pulmonary shunt placement or unifocalisation had limited effect on prognosis in the absence of total repair (p = 0.167). ConclusionsPatients with PA-VSD-MAPCAs who underwent complete intracardiac repair and/or with well-developed native pulmonary arteries had the best prognosis. Our analyzed data suggest that incomplete surgical repair resulted in survival rates comparable to those seen with a non-surgical approach.

Abstract Mo032: Biofabrication of Small Vascular Graft using Human Amniotic Membrane

Vascular diseases encompass a spectrum of pathological conditions affecting blood vessels, including cerebrovascular disease, coronary heart disease, aneurysms, deep vein thrombosis, and peripheral arterial disease. In severe cases, surgical interventions such as bypass grafting or vascular replacement surgeries are necessary to restore blood flow by bypassing obstructed vessels with functional vascular substitutes. Autologous blood vessels harvested from patients are considered the gold standard for vascular surgeries. However, their availability is limited in patients with pre-existing chronic diseases or previous vessel harvest, and the associated morbidities of vessel harvesting and subsequent surgeries further restrict their therapeutic applicability. Synthetic grafts, including polytetrafluoroethylene (e-PTFE), polyethylene terephthalate (PET), and polyurethane (PU), have obtained FDA approval for clinical application and have shown satisfactory outcomes in large vessel surgeries (internal diameter &gt; 6mm). However, clinical trials targeting medium (6-10 mm) to small (&lt; 6mm) vessels often yield unsatisfactory results. This study aims to develop a small vascular graft using human amniotic membrane (HAM) that meets the structural, mechanical, and biological requirements for human vascular reconstructive surgeries. Fresh HAMs were decellularized with 1% Triton X-100 and 0.1% sodium dodecyl sulfate to prepare decellularized HAM (DAM). The DAM was trimmed into a rectangular shape and rolled around a catheter to prepare a tubular-shaped DAM vascular graft. After rolling, the DAM grafts were crosslinked with 1% genipin for 24 hours followed by thorough water washing. The final DAM vascular graft exhibited a multi-layered wall structure and comparable dimensions and mechanical properties to native arteries. The DAM vascular graft was further evaluated in vivo by replacing part of the rat abdominal aorta and part of the carotid artery in pigs. Both small and large animal studies demonstrated vascular patency with no neointimal hyperplasia (NIH), suggesting that the DAM graft holds significant promise as a small tissue-engineered vascular graft for future vascular reconstruction surgeries.

PATENT DUCTUS ARTERIOSUS STENTING IN NEWBORNS AND INFANTS WITH CYANOTIC CONGENITAL HEART DEFECTS: EXPERIENCE AND OUTCOMES

Background. Among all congenital heart defects (CHD), one-third are cyanotic defects with duct-dependent pulmonary blood flow. Palliative interventions are necessary for children with complex cyanotic CHD, premature infants, and children with complex comorbidities. Ensuring a reliable source of pulmonary blood flow adequate for arterial oxygenation and native pulmonary artery branches growth are the primary goals of staged interventions. The classic approach to providing adequate pulmonary blood flow before total repair is systemic-to-pulmonary artery shunting. Currently, there is a growing trend towards the use of an alternative method - transcatheter patent ductus arteriosus (PDA) stenting. Aim: Demonstrate the experience of PDA stenting, immediate and long-term outcomes in newborns and infants. Materials and Methods. From 2009 to April 2024, PDA stenting was performed in 66 patients at the UCC. Among the all cohort, 49 (74.2%) were newborns (Group I), and 17 (25.7%) were infants (Group II). The average age was: Group I - 7.4±5.9 days (range 1 to 28 days), and Group II - 105.2±54.78 days (range 42 to 280 days). The average weight was: Group I - 3.0±0.49 kg (range 1.9 to 4.4 kg), and Group II - 5.2±1.4 kg (range 2.7 to 9 kg). This study analyzed pre-, intra-, and postoperative parameters including age, weight, presence of concomitant/genetic pathology, saturation level, pulmonary artery branches diameter, Nakata index, PDAs size, origin and type, duration of staying in the intensive care unit, duration of artificial lung ventilation and inotropic support, early and late postoperative complications, 30-day and inter-stage mortality rates in the two patient groups. Results. All cases of transcatheter stent implantation were performed by transfemoral access. The average ICU stay duration for Group I was 13.8±9.52 days (range 2 to 119 days), and for Group II was 6.4±3.64 days (range 2 to 20 days). The duration of artificial lung ventilation in Group I was 185.8±165.28 hours (range 2 to 2066 hours), and in Group II was 67.5±46.15 hours (range 4 to 248 hours). Inotropic support - on average for Group I - 151.6±81.06 hours (range 0 to 720 hours), and for Group II - 82.4±47 hours (range 0 to 211 hours). Saturation increased from an average of 65.7±11.03% to 85.2±5.7% in Group I (p&lt;0.05), and from 66.8±10.9% to 87.4±4.24% in Group II (p&lt;0.05). Early postoperative complications were observed in 34.6% (17/49) of Group I patients and 23.5% (4/17) of Group II patients. The early 30-day mortality rate was 8.1% (4/49) for Group I. The next stage of surgical treatment wasperformed on average after 12.9±10.2 months by 51% (25/49) of Group I patients and by 88% (15/17) of Group II patients, on average after 14.98±12 months post-stenting. The interstage (late) mortality rate was 6.1% (3/49) for Group I and 5.8% (1/17) for Group II. Conclusion. Considering the outcomes after PDA stenting in our cohort of patients, this procedure appears to be an effective operation for providing a reliable source of pulmonary blood flow in various anatomical variants of cyanotic CHD in both newborns and infants.

Redefining vascular repair: revealing cellular responses on PEUU-gelatin electrospun vascular grafts for endothelialization and immune responses on in vitro models.

Tissue-engineered vascular grafts (TEVGs) poised for regenerative applications are central to effective vascular repair, with their efficacy being significantly influenced by scaffold architecture and the strategic distribution of bioactive molecules either embedded within the scaffold or elicited from responsive tissues. Despite substantial advancements over recent decades, a thorough understanding of the critical cellular dynamics for clinical success remains to be fully elucidated. Graft failure, often ascribed to thrombogenesis, intimal hyperplasia, or calcification, is predominantly linked to improperly modulated inflammatory reactions. The orchestrated behavior of repopulating cells is crucial for both initial endothelialization and the subsequent differentiation of vascular wall stem cells into functional phenotypes. This necessitates the TEVG to provide an optimal milieu wherein immune cells can promote early angiogenesis and cell recruitment, all while averting persistent inflammation. In this study, we present an innovative TEVG designed to enhance cellular responses by integrating a physicochemical gradient through a multilayered structure utilizing synthetic (poly (ester urethane urea), PEUU) and natural polymers (Gelatin B), thereby modulating inflammatory reactions. The luminal surface is functionalized with a four-arm polyethylene glycol (P4A) to mitigate thrombogenesis, while the incorporation of adhesive peptides (RGD/SV) fosters the adhesion and maturation of functional endothelial cells. The resultant multilayered TEVG, with a diameter of 3.0cm and a length of 11cm, exhibits differential porosity along its layers and mechanical properties commensurate with those of native porcine carotid arteries. Analyses indicate high biocompatibility and low thrombogenicity while enabling luminal endothelialization and functional phenotypic behavior, thus limiting inflammation in in-vitro models. The vascular wall demonstrated low immunogenicity with an initial acute inflammatory phase, transitioning towards a pro-regenerative M2 macrophage-predominant phase. These findings underscore the potential of the designed TEVG in inducing favorable immunomodulatory and pro-regenerative environments, thus holding promise for future clinical applications in vascular tissue engineering.

Mid-term Outcomes of Image-Guided Surgical Thromboembolectomy and Routine Intraoperative Angiography for Native Vessel Acute Lower-Limb-Threatening Ischemia.

Standard balloon-catheter thromboembolectomy (TE) is an established effective treatment for acute lower-limb ischemia (ALI) with recognized limitations when there is an underlying arterial lesion or thromboembolism of the infrapopliteal arteries. The aim of this study was to evaluate the efficacy and safety of image-guided surgical TE combined with routine intraoperative completion angiography in the treatment of ALI patients. Between September 2020 and August 2022, this prospective study included all consecutive adult patients presenting to a tertiary center with unilateral ALI of Rutherford class II due to thromboembolic occlusion of native arteries who underwent image-guided surgical TE and routine completion intraoperative angiography. Adjunctive endovascular techniques (hybrid revascularization) including plain balloon angioplasty (PTA)±stenting or on-table lysis were used if underlying arterial lesions or residual thrombosis were detected on the intraoperative angiography, respectively. The primary outcome measures included technical success and 30-day major amputation rate. Perioperative complications, 1-year primary and secondary patency, limb salvage, mortality, and amputation-free survival rates were endorsed as secondary outcome measures. Image-guided surgical thrombectomy was done for 109 ALI patients (109 limbs), provisionally diagnosed as embolic (57 patients, 52.3%) or thrombotic (52 patients, 47.7%) arterial occlusion. Thromboembolectomy without adjunctive endovascular treatment was done in 38 patients (34.86%), whereas 71 patients (65.14%) required adjunctive PTA±stenting of underlying arterial lesions (60, 55.05%) or on-table lysis±PTA of residual thrombosis (11, 10.09%). The overall technical success rate was 92.66%. At 30 days, amputation and mortality rates were 3.67% and 5.5%, respectively. None of the patients had thrombectomy-induced arterial injuries. One-year follow-up data were available for 81 patients (74.3%). The Kaplan-Meier estimate of the 12-month primary and secondary patency, limb salvage, and amputation-free survival rates was 76.5%±0.04, 91.5%±0.03, 90.6±0.03, and 91.4±0.03%, respectively. Image-guided TE combined with routine intraoperative angiography is a safe and effective technique for surgical TE in acute lower-limb ischemia patients with the advantage of immediate identification and treatment of underlying arterial lesions or residual thrombosis for optimal revascularization. The present study has confirmed the safety and effectiveness of image-guided thromboembolectomy combined with routine use of intraoperative angiography during surgical treatment of acute lower limb ischemia in terms of immediate identification and treatment of underlying arterial lesions or residual thrombosis for optimal revascularization. This technique also facilitates selective passage of Fogarty balloon catheter into infrapopliteal arteries from the femoral approach which is traditionally done by exploration of the popliteal trifurcation or tibial arteries under regional or general anesthesia. Using this technique can guide the operating surgeon for adequate balloon manipulation and inflation to avoid iatrogenic vessel injury.

Nonlinear Elasticity of Blood Vessels and Vascular Grafts.

The transplantation of vascular grafts has emerged as a prevailing approach to address vascular disorders. However, the development of small-diameter vascular grafts is still in progress, as they serve in a more complicated mechanical environment than their counterparts with larger diameters. The biocompatibility and functional characteristics of small-diameter vascular grafts have been well developed; however, mismatch in mechanical properties between the vascular grafts and native arteries has not been accomplished, which might facilitate the long-term patency of small-diameter vascular grafts. From a point of view in mechanics, mimicking the nonlinear elastic mechanical behavior exhibited by natural blood vessels might be the state-of-the-art in designing vascular grafts. This review centers on elucidating the nonlinear elastic behavior of natural blood vessels and vascular grafts. The biological functionality and limitations associated with as-reported vascular grafts are meticulously reviewed and the future trajectory for fabricating biomimetic small-diameter grafts is discussed. This review might provide a different insight from the traditional design and fabrication of artificial vascular grafts.

Atopic dermatitis is associated with an increased risk of cardiovascular diseases: a large-scale, propensity-score matched US-based retrospective study.

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease characterized by intense itch, and impacting heavily on patients' and caregivers' quality of life. Its clinical presentation is accompanied by a variety of comorbidities associated with type 2 inflammation, such as asthma, hay fever and food allergies. However, current data on cardiovascular comorbidities are inconsistent. To identify the risk of cardiovascular diseases (CVDs) in patients with AD. Data from electronic health records of 1 070 965 patients with AD and equally distributed propensity-score matched controls were retrieved from the US Collaborative Network, part of the federated TriNetX network. Hazard ratios (HRs) for the risk of onset of CVDs with a prevalence of ≥ 1% in both cohorts within 20 years after diagnosis were determined. In total, 55 CVDs belonging to 8 major cardiovascular groups were identified. Of those, 53 diagnoses displayed a significantly increased risk in patients with AD. Different diagnoses of heart failure and heart disease were found most often, followed by valve insufficiencies, arrhythmia, tachycardia, atrial fibrillation and flutter, but also major adverse cardiovascular events and venous thromboembolism. The highest HRs were displayed by the individual diagnoses of venous insufficiency, atherosclerosis of native arteries of the extremities, and unspecified diastolic (congestive) heart failure. AD is associated with an increased risk for multiple CVDs.

Transformation of metallo-elastomer grafts in a carotid artery interposition model over a year

Current vascular grafts, primarily Gore-Tex® and Dacron®, don't integrate with the host and have low patency in small-diameter vessels (<6 mm). Biomaterials that possess appropriate viscoelasticity, compliance, and high biocompatibility are essential for their application in small blood vessels. We have developed metal ion crosslinked poly(propanediol-co-(hydroxyphenyl methylene)amino-propanediol sebacate) (M-PAS), a biodegradable elastomer with a wide range of mechanical properties. We call these materials metallo-elastomers. An initial test on Zn-, Fe-, and Cu-PAS grafts reveals that Cu-PAS is the most suitable because of its excellent elastic recoil and well-balanced polymer degradation/tissue regeneration rate. Here we report host remodeling of Cu-PAS vascular grafts in rats over one year. 76 % of the grafts remain patent and >90 % of the synthetic polymer is degraded by 12 months. Extensive cell infiltration leads to a positive host remodeling. The remodeled grafts feature a fully endothelialized lumen. Circumferentially organized smooth muscle cells, elastin fibers, and widespread mature collagen give the neoarteries mechanical properties similar to native arteries. Proteomic analysis further reveals the presence of important vascular proteins in the neoarteries. Evidence suggests that Cu-PAS is a promising material for engineering small blood vessels.

Acute and Mid-Term Results of Atherectomy in Femoropopliteal Lesions.

The femoropopliteal arteries are commonly affected by atherosclerotic lesions. The use of atherectomy may increase the benefit of definitive therapy, such as drug-coated balloon (DCB) angioplasty. To analyze the 2-year safety and efficacy of atherectomy in general and stratified by directional atherectomy (DA) and front-cutting atherectomy (FA) for the treatment of atherosclerotic lesions of the femoropopliteal arteries. A retrospective analysis was performed including patients who underwent vessel preparation with atherectomy. The primary endpoint was the 2-year incidence of target lesion revascularization (TLR). Secondary endpoints included primary patency, changes in ankle-brachial index (ABI) and Rutherford-Becker class (RBC), and amputation rate up to 2 years. Nine hundred and fifty-five patients (37.8% female; mean age: 69.7±9.6 years) were included in this analysis. Eight hundred and twenty-one patients (86%) were claudicants, 134 patients (14%) had critical limb-threatening ischemia. Six hundred and forty-four lesions (67.4%) were in a native artery and 145 lesions (15.2%) were in-stent restenoses. In 166 patients (17.4%), atherectomy was performed in native and in-stent segments. Eight hundred and thirty-seven patients were treated with DA and 118 patients with FA. Five-hundred and seventy-four procedures (60.1%) were followed by DCB angioplasty, provisional stent rate was 20% overall. One hundred and fifty-four procedure-related adverse events (16.1%) were documented, four complications (0.4%) required surgical intervention. At 2 years, 279 patients (34.3%) required TLR. After DA, TLR rates were 9%, 19.5%, and 32.2% at 6, 12, and 24 months, respectively, and 14.2%, 29.4%, and 49%, at 6, 12, and 24 months after FA. After DA, primary patency rates were 75.9%, 57.4%, and 40.3% at 6, 12, and 24 months, respectively, and 64.9%, 44.8%, and 26%, at 6, 12, and 24 months, respectively, after FA. Mean ABI and mean RBC improved significantly during follow-up (p<0.001), 17 patients required amputation, 13 minor (1.6%) and four major (0.5%). Regression analysis shows that more calcified lesions are more likely to have a TLR. Compared with a vessel diameter of 4 mm or smaller, larger diameters are associated with fewer TLRs. In this retrospective analysis, atherectomy of femoropopliteal lesions shows satisfactory mid-term results. German Clinical Trials Register: DRKS00031245. The results of this analysis could influence the daily practice of the interventionalists. A combination of atherectomy as vessel preparation followed by drug coated balloon angioplasty appears to be promising, but would need to be investigated in randomised trials.

Totally percutaneous endovascular renal allograft salvage for common iliac artery pseudoaneurysm

Delayed presentation of recipient artery pseudoaneurysms following kidney transplantation is a rare, yet critical, complication. Although the precise etiology remains unclear, factors such as chronic steroid use, iatrogenic injuries (including vascular clamp damage during index surgery), or infections could contribute. Timely surgical intervention is imperative to prevent arterial rupture and life-threatening bleeding. Open repair, although commonly used, is associated with notable mortality rates and graft loss. Endovascular repair for delayed presentations of native iliac artery pseudoaneurysms has seen limited documentation in the literature. We present a case involving salvage of a kidney graft through innovative application of an endovascular technique using a modified stent graft with fenestration for the transplanted renal artery. The pseudoaneurysm, discovered 4 years after transplantation, was situated in proximity to the anastomosis site of the kidney graft’s renal artery to recipient common iliac artery. Traditional open repair posed significant risks of graft loss due to its location near the kidney allograft. Our approach successfully resolved the issue, preserving graft function and resulting in a short length of hospital stay. This case contributes to the limited body of knowledge on delayed presentation of pseudoaneurysms after kidney transplantation. Successful application of an endovascular approach underscores its potential as a safe and effective alternative to open repair, offering favorable outcomes in terms of patient morbidity, mortality, and graft salvage.

Safety, Efficacy and Outcome of Rotational Thrombectomy assisted Endovascular Revascularisation of the Superior Mesenteric Artery in Acute Thromboembolic Mesenteric Ischaemia.

To evaluate the efficacy and safety of percutaneous rotational thrombectomy-assisted endovascular revascularization of acute thromboembolic superior mesenteric artery occlusions in acute mesenteric ischemia. Fifteen cases of percutaneous rotational thrombectomy- assisted (Rotarex S, BD, USA) revascularization were retrospectively analyzed. The etiology was embolic in 40 % of cases and thrombotic in 60 %. A "Thrombectomy in Visceral Ischemia" (TIVI) 5-point score determined vessel patency at presentation, after percutaneous rotational thrombectomy, and after adjunctive technologies. TIVI 3 indicated nearly complete revascularization (minimal residual side branch thrombus). TIVI 4 indicated complete revascularization. Technical success was defined as successful device application and a final TIVI score of 3/4 after adjunctive technologies. Safety and outcome were also analyzed. Device application via femoral access was feasible in 100 % of cases and improved flow in 86.7 % of cases (1 × TIVI 0→1, 11 × TIVI 0→2, 1 × TIVI 1→2). There was no change in 13.3 % of cases (2 × TIVI 2→2). Additional devices resulted in further flow improvement in 93.3 % of cases (8 × TIVI 3, 6 × TIVI 4). One recanalization failed (TIVI 2→2→2). After adjunctive technologies (10 × manual aspiration, 11 × angioplasty, 9 × stenting), the technical success rate was 93.3 %. The mean procedure time was 40.5(± 14) minutes for embolism and 72.1(± 20) minutes for thrombosis. There was one device-related major complication (catheter tip fracture) resulting in a device-related safety rate of 93.3 %. The overall major complication rate was 20 %. Surgical exploration (13 ×), bowel resection (9 ×) and Fogarty embolectomy/bypass (3 ×) were also performed. The 30-day mortality rate was 40 %. Percutaneous rotational thrombectomy is an effective adjunct for rapid endovascular recanalization of acute thromboembolic superior mesenteric artery occlusions with an acceptable rate of major procedural complications. · Percutaneous rotational thrombectomy-assisted superior mesenteric artery revascularization in acute occlusive mesenteric ischemia is feasible and effective.. · Percutaneous rotational thrombectomy facilitates rapid flow restoration in native and stented superior mesenteric artery segments.. · Brachial access should be considered in the case of steep take-off angles of the superior mesenteric artery..

Morphologic features of prostate cancer-encased native vessels: An image analysis study

BackgroundVasculature plays a crucial role in the progression of prostate cancer (PC). Changes to the prostatic native vessels have not been studied since 2000 when Garcia et al. demonstrated marked media hypercellularity and increased artery thickness in prostatic native arteries within PC. We aim to further evaluate and characterize prostatic native vessels with a more accurate method with the use of virtual slides and digital analysis. DesignPathologist-annotated whole-mount digital slides from 96 entirely submitted prostatectomies were annotated for PC (color-coded by Gleason) using Omero platform. A subset of 44 cases met criteria for further analysis of media thickness, cellularity, and wall thickness to lumen ratio. Cases were included based on containing ≥5 native arteries (≥100 µm diameter) encased on at least 3 sides by PC, with vessels (≥100 µm diameter) designated as controls if they were ≥ 1000 µm away from PC. Annotated vessels were segmented and processed using Matlab 2023b. Mean media thickness (corrected for oblique sections), media: lumen ratio (based on numbers of pixels), and media cellularity (nuclei count) were studied by analysis with SPSS by linear mixed model with nested random effects for subject and slide to account for repeated measures. ResultsVessels encased by PC showed greater media thickness (p=0.02), cellularity (p=0.02) and wall thickness/lumen ratio (p= <0.001) compared to vessels away from PC. These values showed an increasing trend according to stage in cellularity (p=0.14), media thickness (p=0.12) and wall thickness/ lumen ratio (p= 0.33) with higher stage (pT3). A Gleason group comparison showed a borderline-significant gradewise trend when analyzing wall thickness/lumen ratio (p=0.06). Grade 5 emerged as significantly different (p=0.02) from grades 3 or 4 non-cribriform. ConclusionsSimilar to the 2000 study, increased media thickness and hypercellularity of vessels encased by PC were evident compared to controls. Borderline grade-dependent increased vessel cellularity changes were seen, suggesting a possible role in PC progression; the predictive value of these changes for outcome is uncertain. Whether the etiology of changes reflects locally increased intravascular pressure of vessels within tumor should be investigated.

Prognostic assessment of coronary artery bypass patients based on coronary CTA: vessel weight and native artery lesions aid in predicting cardiovascular events

Prognostic assessment of coronary artery bypass patients based on coronary CTA: vessel weight and native artery lesions aid in predicting cardiovascular events