Management of a Mycotic Aneurysm in a Patient with COVID-19: A Case Report.

The aim of this paper is to share our experience in managing a patient with Klebsiella pneumoniae mycotic abdominal aortic aneurysm who was also infected with COVID-19. A 69-year-old male was transferred to our hospital for the management of an infra-renal mycotic abdominal aortic aneurysm. During his hospital course, the patient contracted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). He was intubated due to respiratory distress. Over a short period, his mycotic aneurysm increased in size from 2.5 cm to 3.9 cm. An emergency repair of his expanding aneurysm was achieved using our previously described protocol of coating endovascular stents with rifampin. The patient was managed with a rifampin-coated endovascular stent graft without any major complications. Postoperatively, the patient did not demonstrate any neurological deficits nor any vascular compromise. He remained afebrile during his postoperative course and was extubated sometime thereafter. He was then transferred to the ward for additional monitoring prior to his discharge to a rehab hospital while being on long-term antibiotics. During his hospital stay, he was monitored with serial ultrasounds to ensure the absence of abscess formation, aortic aneurysm growth or graft endoleak. At 6 weeks after stent graft placement, he underwent a CT scan, which showed a patent stent graft, with a residual sac size of 2.5 cm without any evidence of abscess or endoleak. Over a follow-up period of 180 days, the patient remained asymptomatic while remaining on long-term antibiotics. Thus, in patients whose surgical risk is prohibitive, endovascular stent grafts can be used as a bridge to definitive surgical management.

Management of traumatic carotid artery dissection: initial experience of a single center.

Traumatic carotid artery dissection (tCAD) bears the risk of hypoperfusion inducing delayed cerebral ischemia. The lack of consensus on standard treatment of tCAD remains a great challenge. Here, we present our successes on a series of patients with delayed tCAD diagnosis and treatment using multimodality treatment strategies. We retrospectively reviewed 21 patients with tCAD treated with carotid artery stent placement or anticoagulation therapy. There were 14 dissection locations (66.67 %) which involved extracranial internal carotid artery (ICA) and seven locations (33.33 %) which involved both extracranial and intracranial ICA. Stenosis severity was 70-99 % in 16 cases (76.19 %) and <70 % in 5 cases (23.81 %). Endovascular stents were administrated to 17 patients with hypoperfusion as evaluated by radiological methods, while anticoagulation therapy was administrated to the other four patients. Carotid revascularization was performed with one (9/17 patients) or multiple (8/17 patients) stents. None of the patients experienced a procedure-related complication. At discharge, the mean modified Rankin Scale (mRS) score of patients was 1.08 ± 0.76. Neither additional neurological deficient nor restenosis happened during the follow-up period. More vigilance is required to assure timely diagnosis of patients with delayed tCAD. Assessment of cerebral perfusion is an effective approach in tCAD treatment in our experience.

The impact of endovascular stents types on perioperative outcomes of ruptured abdominal aortic aneurysms: a single-center experience.

Introduction: Ruptured abdominal aortic aneurysm (rAAA) represents a critically urgent vascular surgical condition, and endovascular aneurysm repair (EVAR) is a clinically effective treatment option. This study aims to investigate whether the type of intravascular graft used for ruptured abdominal aortic aneurysms has an impact on perioperative outcomes of EVAR. Methods: A retrospective analysis was conducted on patients who underwent EVAR for ruptured abdominal aortic aneurysm at a single medical center from 2019 to 2022. Patients who required simultaneous stent implantation in the renal arteries or visceral arteries, as well as those with ruptured aneurysms located in the para-renal, supra-renal, or thoracoabdominal regions, were excluded from the analysis. Additionally, patients who underwent open surgery during the initial procedure or converted to open repair were excluded. The primary endpoint was perioperative mortality rate. Other study outcomes included perioperative complications, reoperation rates, and length of hospital stay. Characteristics and corresponding outcomes of patients receiving different endovascular stent treatments were compared using SPSS software. Results: A total of 58 patients received treatment with two types of endovascular stents: Gore Excluder (n = 29) and Microport Hercules (n = 29). The number of other endografts was too small for statistical analysis. Compared to patients treated with Hercules, those treated with Excluder had a significantly increased likelihood of concomitant coronary atherosclerosis (P = 0.009) and potentially higher creatinine levels (P = 0.014). Additionally, Excluder was more commonly used in patients with shorter aneurysm necks (P < 0.001). There was a statistically significant difference in overall mortality between the two groups (Hercules 27.6%, Excluder 6.9%, P = 0.037). Furthermore, patients who received Excluder treatment had lower mortality rates in subgroups of non-alcohol users (P = 0.028), non-diabetic patients (P = 0.027), and patients with dispersed thrombosis at the proximal neck (P = 0.046). In the multivariate analysis, the type of stent used (OR 0.06, 95% CI 0.00-1.31) and the occurrence of intraoperative complications (OR 20.70, 95% CI 1.14-76.70) in patients with rAAA was identified as an independent risk factor for perioperative mortality. Conclusion: Our study suggests that the management of intraoperative complications may be a modifiable factor that can improve outcomes. Patients receiving Excluder treatment demonstrated better performance in EVAR for single-center rAAA patients compared to other endovascular stents, and this difference warrants further investigation.

Camouflaging endovascular stents with an endothelial coat using CD31 domain 1 and 2 mimetic peptides.

Objective: Implantation of an endovascular device disrupts the homeostatic CD31:CD31 interactions among quiescent endothelial cells (ECs), platelets, and circulating leukocytes. The aim of this study was to design an endothelial-mimetic coating of nitinol and cobalt-chromium (CoCr) surfaces and stents using synthetic CD31 peptides, to promote device endothelialization and pacific integration within the arterial wall. Methods: Peptides mimicking the domains 1 (D1) and 2 (D2) of CD31 were synthetized and immobilized onto experimental nitinol and CoCr surfaces using a three-step, dip-coating, mussel-inspired protocol using copper-free click chemistry. Human aortic EC phenotype and endothelialization assessment using parallel scratch tests were carried out using five synthetic CD31 peptides coated on 4.8-mm nitinol and CoCr flat disks and were compared with control disks. The CD31 peptide exhibiting the best results in vitro was then immobilized on clinical-grade 3 × 40-mm self-expanding nitinol and 2.5 × 20.0-mm balloon-expandable CoCr stents. Such devices were implanted in native arteries of White New Zealand rabbits, and compared with control uncoated bare metal stents (BMS) and drug-eluting stents 7 and 30 days after implantation using resin cross-sections and scanning electron microscopy (n = 2-3 per group at each time point). Results: Membrane-distal CD31 D1 and D2 peptides exhibited a distinct capability to foster a healthy endothelial phenotype and to promote endothelialization in vitro. By day 7 after implantation, CD31 nitinol and CoCr stents were evenly covered by wholesome ECs, devoid of thromboinflammatory signs, in contrast with both BMS and drug-eluting stents. Such results were consistent until day 30. Conclusions: Membrane-distal CD31 biomimetic peptides seem to camouflage the device surface effectively, preventing local reactions and promoting rapid and seamless endovascular integration.

Magnetic Particle Imaging: In vitro Signal Analysis and Lumen Quantification of 21 Endovascular Stents.

PURPOSE: Endovascular stents are medical devices, which are implanted in stenosed blood vessels to ensure sufficient blood flow. Due to a high rate of in-stent re-stenoses, there is the need of a noninvasive imaging method for the early detection of stent occlusion. The evaluation of the stent lumen with computed tomography (CT) and magnetic resonance imaging (MRI) is limited by material-induced artifacts. The purpose of this work is to investigate the potential of the tracer-based modality magnetic particle imaging (MPI) for stent lumen visualization and quantification. METHODS: In this in vitro study, 21 endovascular stents were investigated in a preclinical MPI scanner. Therefore, the stents were implanted in vessel phantoms. For the signal analysis, the phantoms were scanned without tracer material, and the signal-to-noise-ratio was analyzed. For the evaluation of potential artifacts and the lumen quantification, the phantoms were filled with diluted tracer agent. To calculate the stent lumen diameter a calibrated threshold value was applied. RESULTS: We can show that it is possible to visualize the lumen of a variety of endovascular stents without material induced artifacts, as the stents do not generate sufficient signals in MPI. The stent lumen quantification showed a direct correlation between the calculated and nominal diameter (r = 0.98). CONCLUSION: In contrast to MRI and CT, MPI is able to visualize and quantify stent lumina very accurately.

Biodegradable stents for coronary artery disease treatment: Recent advances and future perspectives.

Cardiovascular diseases are one of the major causes of human death in the world. Endovascular stents are the most important implantation devices in cardiovascular intervention, and their efficacy determines the success of cardiovascular disease treatment. In order to reduce the long-term side effects of permanent metallic stents, such as subacute thrombosis and in-stent restenosis, a new generation of endovascular stents so-called "biodegradable stents (BDSs)" is currently being vigorously developed and considered as the most promising candidate. BDS research in the last two decades has been mainly focused on biodegradable polymeric, iron-, magnesium- and zinc-based stent materials. In this review, we first summarized the properties of various BDSs, such as mechanical property, degradation performance, biocompatibility, etc. We then illustrated the working principle of BDSs and their desirable features, which require a compromise between radial support and degradation. We finally discussed the future research strategies in successful BDS development, including the oprimization of stent structures using finite element design, and the improvement in the mechanical properties/corrosion performance/biocompatibility, as well as the drug loading design on BDSs. We also addressed the limitation and deficiency of existing BDSs in order to overcome them in future BDS development and applications.

Reintervention Is Associated With Improved Survival in Pediatric Patients With Pulmonary Vein Stenosis.

OBJECTIVES: The aim of this study was to evaluate survival following catheter intervention in pediatric patients with pulmonary vein stenosis (PVS). BACKGROUND: Despite aggressive surgical and catheter intervention on PVS in children, recurrence and progression of stenosis can lead to right heart failure and death. Clinicians continue to seek effective treatment options for PVS. METHODS: A single-center, retrospective study was performed including all patients <18 years of age who underwent catheter intervention (balloon angioplasty and bare-metal stent and drug-eluting stent insertion) on PVS. Endpoints included death, vein loss, and rate of reintervention. RESULTS: Thirty patients underwent intervention (balloon angioplasty, n = 9; bare-metal stent, n = 5; drug-eluting stent, n = 16) at a median age of 6.4 months (4.3 to 9.9 months). Median follow-up duration was 30.6 months (77 days to 10.5 years). Fourteen patients (47%) died at a median of 2.0 months (0.4 to 3.2 months) following intervention. There was no association between DES placement and survival (p = 0.067). Reintervention (catheter or surgical) was associated with improved survival (p = 0.001), with a 1-year survival rate of 84% compared with 25% for no reintervention. Vein loss occurred in 34 of 58 (59%) veins at a median of 3.3 months (1.0 to 5.0 months). One-year vein survival was higher with DES implantation (p = 0.031) and with reintervention (p < 0.001). CONCLUSIONS: DES implantation at first catheter intervention appears to be associated with improved vein survival but may not result in improved patient survival. However, reintervention appears to be associated with improved patient survival and vein patency, suggesting that despite mode of treatment, frequent surveillance is important in the care of these patients.

Multidetector CT Evaluation in Arterial Stenting.

BACKGROUND: Multidetector CT (MDCT) represents breakthrough in CT technology, significantly improving CT Angiography applications. METHODS: Twenty one patients with aortoiliac & branch aneurysms or stenosis were evaluated by Digital Subtraction Angiography (DSA) and Multidetector CT (MDCT) before and after endovascular repair. RESULTS: There were eight cases of aortic & branch aneurysms and 13 with stenosis. Four cases had aortic aneurysms, while one case had left subclavian artery aneurysm, thoracic aneurysm, femoral and popliteal artery pseudoaneurysms. Of the 13 cases with stenotic lesions, iliac stenosis was seen in eight patients. The others included carotid, vertebral, aortic, renal and aortic bifurcation stenotic. MDCT offered accurate information on shape and size of aneurysm, shape and patency of graft, the presence or absence of perigraft thrombosis or endoleaks, while in stenotic lesions it provided useful information on shape of graft, its location, its patency and the presence and quantity of distal flow. CONCLUSION: MDCT was found to be a potentially useful modality during initial evaluation and follow up of patient undergoing endovascular repair.

An experimental assessment of catheter trackability forces with tortuosity parameters along patient-specific coronary phantoms.

Coronary artery disease is one of the leading causes of cardiovascular deaths worldwide. Approximately 70% of patients requiring coronary revascularisation receive endovascular stents. The endovascular procedure is the preferred option due to its minimally invasive nature when compared to open heart surgery. Stent delivery is paramount for the success of the endovascular procedure. Catheter delivery forces within tortuous blood vessels can produce vasoconstriction and injury, resulting in reactive intimal proliferation or distal embolisation associated with end-organ ischaemia and infarction. Trackability is evaluated by most medical device companies for further development of their delivery systems. Relevant device design attributes must be tested in settings which simulate aspects of the intended use conditions, such as vessel geometry and compliance. Various tortuosity parameters are used to facilitate endovascular intervention planning. This study assessed the significance and correlation between the trackability forces for a coronary stent system with various geometrical parameters based on patient-specific geometries. A motorised delivery system delivered a commercially available coronary stent system and monitored the trackability forces along three phantom patient-specific thin-walled, compliant coronary vessels supported by a cardiac phantom model. The maximum trackability forces, curvature and torsion values ranged from 0.31 to 0.87 N, 0.06 to 0.22 mm(-1) and -11.1 to 5.8 mm(-1), respectively. The trackability forces were significantly different between all vessels (p < 0.002), while the tortuosity parameters were not significantly different (p > 0.05). A new tortuosity parameter-coined tracking curvature which considers the lumen radius as well as the curvature along the centreline was statistically different (p < 0.002) for all vessels and correlated with the trackability forces. There was a strong correlation between the cumulative trackability force and the cumulative tracking curvature. Tracking curvature could be used as a predictive clinical tool to aid stent delivery to the vicinity of the lesion.

The Effects That Cardiac Motion has on Coronary Hemodynamics and Catheter Trackability Forces for the Treatment of Coronary Artery Disease: An In Vitro Assessment.

The coronary arterial tree experiences large displacements due to the contraction and expansion of the cardiac muscle and may influence coronary haemodynamics and stent placement. The accurate measurement of catheter trackability forces within physiological relevant test systems is required for optimum catheter design. The effects of cardiac motion on coronary flowrates, pressure drops, and stent delivery has not been previously experimentally assessed. A cardiac simulator was designed and manufactured which replicates physiological coronary flowrates and cardiac motion within a patient-specific geometry. A motorized delivery system delivered a commercially available coronary stent system and monitored the trackability forces along three phantom patient-specific thin walled compliant coronary vessels supported by a dynamic cardiac phantom model. Pressure drop variation is more sensitive to cardiac motion than outlet flowrates. Maximum pressure drops varied from 7 to 49 mmHg for a stenosis % area reduction of 56 to 90%. There was a strong positive linear correlation of cumulative trackability force with the cumulative curvature. The maximum trackability forces and curvature ranged from 0.24 to 0.87 N and 0.06 to 0.22 mm(-1) respectively for all three vessels. There were maximum and average percentage differences in trackability forces of (23-49%) and (1.9-5.2%) respectively when comparing a static pressure case with the inclusion of pulsatile flow and cardiac motion. Cardiac motion with pulsatile flow significantly altered (p value <0.001) the trackability forces along the delivery pathways with high local percentage variations and pressure drop measurements.

Endovascular Gene Delivery from a Stent Platform: Gene- Eluting Stents.

A synergistic impact of research in the fields of post-angioplasty restenosis, drug-eluting stents and vascular gene therapy over the past 15 years has shaped the concept of gene-eluting stents. Gene-eluting stents hold promise of overcoming some biological and technical problems inherent to drug-eluting stent technology. As the field of gene-eluting stents matures it becomes evident that all three main design modules of a gene-eluting stent: a therapeutic transgene, a vector and a delivery system are equally important for accomplishing sustained inhibition of neointimal formation in arteries treated with gene delivery stents. This review summarizes prior work on stent-based gene delivery and discusses the main optimization strategies required to move the field of gene-eluting stents to clinical translation.

Efficacy analysis of endovascular stenting for aortic arch artery stenosis after nasopharyngeal carcinoma radiotherapy / 中国脑血管病杂志

Objective To investigate the efficacy of endovascular stenting for aortic arch artery stenosis after nasopharyngeal carcinoma radiotherapy. Methods The clinical data of 8 patients with symptomatic severe aortic arch artery stenosis after nasopharyngeal carcinoma radiotherapy were analyzed retrospectively. The patients were all received endovascular stenting,and their improvement of cerebral ischemic symptoms was observed. They were followed up by cervical color Doppler ultrasound.Results The whole brain vascular DSA confirmed that there were 24 severe arterial stenoses on the aortic arch arteries of extracranial segments in 8 patients,including 11 in internal carotid artery,2 in common carotid artery,10 in vertebral artery and 1 in subclavian artery. The patients were treated with vascular angioplasty and stenting respectively. All the patients were followed up for 1 year;there were no recurrence of cerebral ischemic symptoms.Cervical color Doppler ultrasound did not reveal any obvious restenosis. Conclusion Endovascular stent angioplasty for the treatment of aortic arch artery stenosis after nasopharyngeal carcinoma radiotherapy is relatively safe and feasible.

Expression and Significance of Plasmic Inflammatory Factor during Perioperative and Follow-up Periods after Endovascular Stents in Patients with Cerebral Arterial Stenosis / 中国康复理论与实践

@#Objective To observe expression and significance of inflammatory factor during perioperative and follow-up periods after endovascular stents in patients with cerebral arterial stenosis.Methods 54 patients diagnosed as cerebral arterial stenosis by digital substraction angiography (DSA) were selected as the stent group and treated with endovascular stents; another 32 subjects had the same disease but not accepted stenting were considered as the control group. Interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) contents were measured at different time points during perioperative and follow-up periods in the two groups. Stage A represented as day one before angiography or catheterization; stage B as 6 hours postoperatively (stent group) or 6 hours after diagnostic angiography (control group); stages C～I as 12, 24, 48, 72 hours, 1 and 6 months after stent insertion (stent group) or the same time points after angiography (control group).Results Contents of IL-6 and hs-CRP of the stent group were similar as the control group in the stage A ( P>0.05), but significantly higher than that of the control group during stages B～I ( P<0.01～0.05). Among 54 patients of the stent group, 21 cases had restenosis 6 months postoperatively (38.89%). Contents of IL-6 and hs-CRP of the patients were similar as those without restenosis in stages A～F postoperatively ( P>0.05), but significantly higher than that of the cases without restenosis in stages G and I postoperatively ( P<0.01～0.05).Conclusion Endovascular stents can increase the contents of IL-6 and hs-CRP of patients with cerebral arterial stenosis; in addition, high expression of them is the risk factor of post-stent restenosis during follow-up period.