Bare Metal Stents Research Articles

Innovations in Vascular Repair from Mechanical Intervention to Regenerative Therapies.

Vascular diseases, including atherosclerosis and thrombosis, are leading causes of morbidity and mortality worldwide, often resulting in vessel stenosis that impairs blood flow and leads to severe clinical outcomes. Traditional mechanical interventions, such as balloon angioplasty and bare-metal stents, provided initial solutions but were limited by restenosis and thrombosis. The advent of drug-eluting stents improved short-term outcomes by inhibiting vascular smooth muscle cell proliferation, however, they faced challenges including delayed reendothelialization and late-stage thrombosis. This review highlights the progression from mechanical to biological interventions in treating vascular stenosis and underscores the need for integrated approaches that combine mechanical precision with regenerative therapies. To address long-term complications, bioresorbable stents were developed to provide temporary scaffolding that gradually dissolves, yet they still encounter challenges with mechanical integrity and optimal degradation rates. Consequently, emerging therapies now focus on biological approaches, such as gene therapy, extracellular vesicle treatments, and cell therapies, that aim to promote vascular repair at the cellular level. These strategies offer the potential for true vascular regeneration by enhancing endothelialization, modulating immune responses, and stimulating angiogenesis. Integrating mechanical precision with regenerative biological therapiesoffers a promising future for treating vascular stenosis. A comprehensive approach combining these modalities could achieve sustainable vascular health.

Effect of rapamycin-eluting stents on in-stent restenosis and early inflammatory response in coronary artery narrowing animal models

Objectiveit was to evaluate the efficacy and safety of rapamycin-eluting stents at different doses in the treatment of coronary artery narrowing in miniature pigs.Methodsa total of 20 miniature pigs were randomly assigned into four groups: S1 group (low-dose rapamycin-coated stent, 55 µg/mm2), S2 group (medium-dose rapamycin-coated stent, 120 µg/mm2), S3 group (high-dose rapamycin-coated stent, 415 µg/mm2), and D0 group (bare metal stent). The stent size was 3.0 mm × 18 mm, with an over-expansion ratio of 1.1. Each group consisted of five pigs. Stent implantation was followed by euthanasia and tissue collection after 1 month. Vascular measurements, inflammatory response scores, cardiovascular injury scores, endothelialization scores, liver and kidney function indices, and myocardial injury markers were compared among the groups.Resultsthe neointimal thickness in the S2 and S3 groups was significantly lower than that in the S1 and D0 groups (S1 group: 24.08 ± 3.95, S2 group: 1.86 ± 0.28, S3 group: 2.72 ± 0.74, D0 group: 22.85 ± 3.15, P < 0.05). The residual lumen area in the S2 and S3 groups was significantly larger than that in the S1 and D0 groups (S1 group: 2.73 ± 0.51, S2 group: 4.25 ± 0.78, S3 group: 3.91 ± 0.73, D0 group: 2.91 ± 0.44, P < 0.05). The neointimal area in the S2 and S3 groups was significantly smaller than that in the S1 and D0 groups (S1 group: 3.44 ± 0.84, S2 group: 1.78 ± 0.25, S3 group: 2.07 ± 0.41, D0 group: 3.43 ± 0.72, P < 0.05). The degree of lumen narrowing in the S2 and S3 groups was significantly lower than that in the S1 and D0 groups (S1 group: 44.25 ± 3.66%, S2 group: 14.19 ± 2.01%, S3 group: 15.29 ± 2.45%, D0 group: 21.79 ± 3.51%, P < 0.05). The inflammation scores of coronary artery walls in the S2 and S3 groups of miniature pigs were markedly lower than those in the S1 and D0 groups (P < 0.05). The cardiovascular injury scores (P = 0.072) and endothelialization scores (P = 0.085) differed slightly among the four groups (P > 0.05). Post-operative liver function indicators (alanine transaminase, aspartate transaminase), kidney function indicators (blood urea nitrogen, serum creatinine), and myocardial injury markers (creatine kinase, creatine kinase-MB) also showed neglectable differences among the four groups (P > 0.05).Conclusionmedium and high doses of rapamycin-eluting stents effectively inhibit neointimal hyperplasia and local vascular inflammatory response in miniature pigs without causing damage to liver and kidney functions or myocardial cells. These stents demonstrate high efficacy and safety. Rapamycin-coated coronary stents, as an effective treatment for coronary artery stenosis, may achieve further improvement in therapeutic efficacy through optimization of drug dosage and stent design.

Biodegradable Stents in the Treatment of Arterial Stenosis.

Arterial diseases (ADs) are a significant health problem, with high mortality and morbidity rates. Endovascular interventions, such as balloon angioplasty (BA), bare-metal stents (BMSs), drug-eluting stents (DESs) and drug-coated balloons (DCBs), have made significant progress in their treatments. However, the issue has not been fully resolved, with restenosis remaining a major concern. In this context, bioresorbable vascular stents (BVSs) have emerged as a promising area of investigation. This manuscript includes articles that assess the use of BVSs. Studies have identified ongoing challenges, such as negative vascular remodeling and elastic recoil post-angioplasty, stent-related injury, and in-stent restenosis following BMS placement. While DESs have mitigated these issues to a considerable extent, their durable structures are unable to prevent late stent thrombosis and delay arterial recovery. BVSs, with their lower support strength and tendency towards thicker scaffolds, increase the risk of scaffold thrombosis. Despite inconsistent study results, the superiority of BVSs over DESs has not been demonstrated in randomized trials, and DES devices continue to be the preferred choice for most cases of arterial disease. Esprit BTK (Abbott Vascular) received approval from the US FDA for below-knee lesions in 2024, offering hope for the use of BVSs in other vascular conditions. Enhancing the design and thickness of BVS scaffolds may open up new possibilities. Large-scale and longer-term comparative studies are still required. This article aims to provide an overview of the use of biodegradable stents in the endovascular treatment of vascular stenosis.

A Bleed From the Distal Anastomosis Site of a Bypass Graft From the Left Common Iliac Artery to the Celiac Trunk Treated With a Surgeon-Modified Fenestrated Endograft.

The use of surgeon-modified fenestrated endograft to treat a bleeding complication in the common iliac artery. An Endurant limb graft was modified on back table in theater after planning the fenestration using a semi-automated centerline. The Endurant stent was planned to land flush at the aortic bifurcation. The Endurant limb was partially deployed until the fenestration opened facing the anastomosis to enable rotation and axial movement of the stent graft, if needed. By obtaining access from the contralateral common femoral artery, the fenestration was cannulated using up-and-over technique and bypass graft cannulated. The Endurant stent graft was then fully deployed. Through a separate puncture in the ipsilateral sheath, the fenestration was re-cannulated using a hydrophilic wire, and a balloon-expandable covered stent was introduced through a 7F sheath and then flared in a kissing fashion along with the Endurant stent. The distal part of the Endurant limb was extended with a bare metal stent into the external iliac artery. Control angiography was satisfactory, and bleeding was controlled. Surgeon-modified stent graft in the iliac arteries can be used even in the context of non-aneurysmal disease to treat patients in high-risk emergency situations and could be part of the armamentarium of the vascular surgeon. Physician-modified endografts are increasingly being used by vascular surgeons and interventional radiologists to treat patients with complex aorto-iliac aneurysms in whom custom-made endograft provided by the manufacturer is too expensive to produce and/or patient requires urgent surgery. Data on the use of physician-modified endografts to treat non-aneurysmal disease is lacking. This technical note highlights the use of physician-modified endograft to treat a patient with bleeding complication from the distal anastomosis of an iliac artery to coeliac trunk bypass graft in whom open surgery posed unacceptable high morbidity and mortality risks. This technical note continues to add more information and knowledge to the vascular surgery / interventional radiology communities on the use of physician-modified endografts and also adds another tool in the armamentarium of teams involved.

The eff ect of standard lipid-lowering therapy and the type of stent on the course of the atherosclerotic process in the coronary arteries in patients with hereditary hypercholesterolemia and acute coronary syndrome

Objective. Тo study the impact of standard hypolipidemic therapy and stent type on the progression of atherosclerosis in coronary arteries in patients with familial hypercholesterolemia and acute coronary syndrome. Material and methods. Analyzed treatment results of 100 patients with familial hypercholesterolemia and acute coronary syndrome, divided into two equal groups. Group 1 received bare-metal stents, while Group 2 received drug-eluting stents. All patients were prescribed standard hypolipidemic therapy to reduce restenosis risk and normalize lipid profiles. Immediate postoperative outcomes included coronary flow restoration and adverse event rates, with long-term assessments focused on lipid profile dynamics and restenosis rates. Results. Coronary flow was restored in 98%, with adverse events occurring in 8% equally across both groups. Hypolipidemic therapy normalized lipid profiles in one-third of patients after 1 month, half after 3 months, and two-thirds after 6 months. Restenosis rates at 6 months were 45.2% in Group 1 and 21.2% in Group 2, escalating to 84.6% and 48% at 12 months. Repeat stent implantation occurred in 14% of Group 1 and 8% of Group 2. Conclusion. Standard hypolipidemic therapy is insufficient for rapid lipid normalization, while drug-eluting stents significantly reduce restenosis risk.

Endothelialization of coronary stents after intra-luminal adenoviral VEGF-A gene transfer in a preclinical porcine restenosis model - Studies with optical coherence tomography, angioscopy, multiphoton and scanning electron microscopy.

Coronary stenting operations have become the main option for the treatment of coronary heart disease. Vessel recovery after stenting has emerged as a critical factor in reducing possible complications. In this study, we evaluated the feasibility, safety and efficacy of locally administered intraluminal gene therapy delivered using a specialized infusion balloon catheter. Sixteen pigs received bare metal stents (BMS) in the left circumflex coronary artery and drug-eluting stents (DES) in the right coronary artery. Adenoviral (Ad) gene transfers (dose 1,5e10 pfu) of VEGF-A and LacZ were performed with a ClearWay™ RX infusion balloon catheter on both stents. In vivo imaging included angiography, OCT and angioscopy. Tissue samples were collected for analyses at day 14 and studied using scanning electron microscopy and multiphoton microscopy. AdVEGF-A accelerated re-endothelialization in the BMS compared to the other groups. The highest restenosis was in the BMS AdLacZ group. DES groups had statistically significant reduced maximum stenosis compared to BMS AdLacZ. No major in-stent thrombosis events were detected. Ex vivo imaging showed that intraarterial imaging is not very accurate in the detection of endothelial layer. Biodistribution of the Ad vector and measured safety parameters (off-target tissues and blood tests) did not show any major safety concerns. Adenoviral gene transfer using the ClearWay™ RX catheter was feasible and safe. AdVEGF-A accelerated re-endothelization in BMS. However, DES showed better outcomes in the short-term regarding restenosis and do not benefit from intraluminal AdVEGF-A gene transfer.

Covered Versus Bare Metal Stents in Chronic Mesenteric Ischaemia Treatment: A Systematic Review and Meta-analysis.

The main treatment for Chronic Mesenteric Ischemia (CMI) is revascularization, typically achieved through stent angioplasty of the superior mesenteric artery, and in certain cases, the celiac trunk. However, long-term outcomes using bare-metal stents have been less than satisfactory. Therefore, we aimed to compare the performance of covered stents (CS) versus bare-metal stents (BMS) in patients treated for CMI. Pubmed, Embase and Cochrane Central Register of Controlled Trials databases were systematically searched for studies of patients with CMI who underwent stenting procedures using BMS or CS. The main outcomes were primary patency and freedom from reintervention. Statistical analysis was performed using R version 3.6. One randomized clinical trial and five observational studies were included. In the pooled analysis, patients undergoing the covered stenting approach haOd a higher primary patency (HR 0.40; 95%CI 0.23-0.68; p<0.01). Additionally, CS also demonstrated significantly superior freedom from reintervention when compared to BMS patients (HR 0.30; 95% CI 0.13-0.71; p<0.01). In patients undergoing transluminal angioplasty with stent placement both in the celiac trunk and superior mesenteric artery, the use of CS indicated superior primary patency and a higher rate of freedom from reintervention compared to BMS. These findings indicate superior outcomes with CS and may suggest their use as the preferred stent option in patients with CMI. However, these findings should be interpreted cautiously due to the limited number of studies, the moderate to serious risk of bias in the included data, and the significant heterogeneity observed. Further high-quality clinical trials are necessary to validate these results and strengthen the evidence base for clinical practice.

Vascular Quality Initiative Assessment of Compliance with Society for Vascular Surgery Practice Guidelines for the Endovascular Management of Claudication.

In 2015, Society for Vascular Surgery guidelines on claudication management were released spanning optimal medical management, procedural, and post-procedure recommendations. Uptake of guidelines and changes to clinical practice over time remain unknown. This study hypothesized that guideline aligned practice increased after guideline release. The Vascular Quality Initiative Peripheral Vascular Intervention (VQI PVI) dataset was queried for years 2010-2021 for cases of claudication from occlusive disease. Only the initial procedure was considered, and subsequent interventions were excluded. The primary endpoint was care aligned with the 2015 SVS claudication treatment guidelines that were possible to evaluate in the VQI PVI dataset. Guideline aligned practice before 2016 was compared to after 2016. A hierarchical regression was used to control for hospital level variation introduced by changing VQI membership during the study timeframe. A majority of the 2015 SVS guideline GRADE 1-A recommendations can be assessed using the VQI PVI dataset. Overall, 93,654 cases were included, 30.9% before 2016 and 69.1% after guideline release. After controlling for hospital level variation, guideline aligned care improved for preoperative smoking cessation, aspirin, clopidogrel, and statin use, and post operative medical therapy with antiplatelet, dual antiplatelet and statin therapy. Guideline aligned care did not change over time for aorto-iliac stent use, covered stent use in calcified aortoiliac disease, or superficial femoral artery stenting for 5-15cm lesions. Guideline aligned care worsened for isolated infrapopliteal treatments and use of bare metal stents for 5-15 cm SFA occlusions. Secondary analysis identified an association between area deprivation index and increased odds of smoking and decreased odds of meeting post-discharge optimal medical therapy. While guideline aligned care improved after guideline release for medical management of claudication, procedural elements did not improve. Those with social deprivation were less likely to receive guideline aligned care for medical management representing a future area of study and improvement. High GRADE recommendations can be tracked using the VQI PVI dataset and should be monitored to help improve care.

Successful Percutaneous Coronary Stenting in End-Stage Liver Disease Patients Awaiting Liver Transplantation.

Coronary artery disease (CAD) is associated with poor outcomes after orthotopic liver transplantation (OLT). We report on six high-risk end-stage liver disease (ESLD) patients who underwent percutaneous coronary intervention (PCI) with bare metal stents during the preoperative evaluation process. There was no mortality or major adverse cardiac event (MACE) within 90 days of OLT. These patients had advanced models for end-stage liver disease sodium (MELD-Na) scores (mean 24.5), thrombocytopenia (mean 70,500 µL⁻¹), and elevated international normalized ratio (INR; mean 2.0), who tolerated stent implantation followed by modified antiplatelet regimens. Percutaneous coronary intervention may facilitate listing with good OLT outcomes.

Midterm Results of the STABILISE Technique in the Treatment of Aortic Dissection.

Background: Contemporary treatments of acute aortic dissection, including medical, surgical, and endovascular options, are remarkably effective at the management of malperfusion and rupture. Unfortunately, long-term studies indicate that 30%-50% of patients need secondary procedures to treat progressive aneurysmal enlargement of the untreated aorta. The Stent-assisted balloon-induced intimal disruption and relamination in aortic dissection repair (STABILISE) technique was introduced to improve long-term outcomes. Purpose: This study aims to investigate the results of the STABILISE technique in patients with aortic dissection. Methods: This is a single-center, retrospective review of all patients treated with the STABILISE technique. There were 12 de novo type B aortic dissection (TBAD) and 7 residual TBAD following type A aortic dissection (TAAD) repair. Results: There was disruption of the dissection membrane and relamination in all or part of the bare metal stent segment in 100% of cases. The average percent attainment of a uni-luminal aorta in comparison to the length with persistent false lumen was 91 ± 12%. Conclusion: Midterm results suggest that the STABILISE technique may improve aortic remodeling after endovascular treatment of acute dissection.

Prediction of in-stent restenosis based on systematic and retrospective analyses

Coronary restenosis is a pressing challenge in cardiovascular diseases with an annual incidence of 3 &amp;ndash; 4%. The aim of the study was to assess the influence of known risk factors in predicting coronary restenosis in a systematic analysis and an original retrospective survey. In the first stage, we performed a systematic review of restenosis risk factors using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. In the second stage, we searched for the restenosis risk factors in 15,000 patients who had undergone coronary angiography, considering risk factors identified during the first stage. From the second stage, we identified 516 patients with restenosis versus 282 patients without restenosis. Coronary risk factors included male sex (hazard ratio [HR] = 2.194; confidence interval [CI]: 1.5 &amp;ndash; 3.22) and history of myocardial infarction (HR = 1.098; CI: 1.05 &amp;ndash; 1.15). Moderate-diameter stenosis (2.75 &amp;ndash; 3.5 mm) exhibited a protective effect on restenosis (HR = 0.713; CI: 0.58 &amp;ndash; 0.87), whereas small-diameter stenosis did not. Drug-eluting stents reduced the risk of restenosis (HR = 0.554; CI: 0.41 &amp;ndash; 0.75). The risk factors for coronary restenosis included male sex, history of myocardial infarction, small-diameter stent, and the use of bare-metal stents.

Cobalt Chromium or Stainless Steel Balloon-Expandable Bare Metal Stents for Iliac Occlusive Disease?

To compare the performance of a new-generation cobalt-chromium balloon-expandable bare metal stent with a stainless steel platform for the treatment of iliac occlusive disease. Consecutive patients treated for symptomatic iliac occlusive disease between 2014 and 2021 with the cobalt-chromium Dynetic-35 or the stainless steel Dynamic platform were retrospectively evaluated. Outcome measures included technical success, device- or procedure-related death, clinically-driven target lesion revascularization (CD-TLR), primary patency, and major index limb amputation up to 12 months. In total, 222 Cobalt chromium (CC) stents were used in 159 patients (34.6% female; mean age 66.9 ± 9.5 years) for the treatment of 216 lesions, while 234 iliac lesions of 182 patients (34.6% female; mean age 66.3 ± 9.9 years) were treated with 252 stainless steel (SS) stents. The mean lesion length (30.2 ± 12.8 mm vs 28.7 ± 22.5 mm, p=0.36) and the mean calcification grade (2.0 vs 1.9, p=0.07) did not differ significantly between the 2 groups. Patients treated by the CC platform were more frequently on statins (p<0.001), whereas more active smokers and subjects with higher Rutherford class underwent a SS deployment (p<0.001). Technical success was significantly higher in the SS group (100% vs 97.3%; p=0.01). This was due to longitudinal deformation or stent dislocation after passing the Dynetic-35 with endovascular material. After 1 year, no difference was found following CC and SS stent deployment in terms of device- or procedure-related deaths (0.6% vs 1.1%, p=0.99), target limb amputations (1.9% vs 1.6%, p=0.99), primary patency (91.3% vs 93.5%), and CD-TLR (6.5% vs 2.8% p=0.07). Through 1 year, cobalt-chromium and stainless steel balloon-expandable stents are safe and effective in the treatment of iliac occlusive disease. Enhanced attention should be given passing the cobalt-chromium stent with endovascular devices to avoid procedural complications. Stents with a thin-strut structure improve the flexibility and deliverability. The lower profile also increases the applicability lowering the risk of vascular access complications. In this study newer-generation cobalt chromium balloon-expandable stent did not confer advantages over stainless steel bare metal stent. On contrary, the technical success was inferior to stainless steel stents as longitudinal deformation or dislocation of the Dynetic-35 occurred. Therefore, enhanced attention should be given passing a Cobalt chromium stent with wires, catheters or sheaths to avoid stent deformation.

Drug-eluting stents versus bare-metal stents for intracranial atherosclerotic stenosis: a systematic review and meta-analysis

BackgroundIn-stent restenosis (ISR) is the primary cause of stroke recurrence after intracranial stenting. Drug-eluting stents (DES) have recently shown great potential for reducing restenosis. This systematic review aimed to evaluate...

Bare metal stent application to prevent limb occlusion in iliac arteries with severe tortuosity during an endovascular aneurysm repair: a cohort study.

The risk of limb graft occlusion (LGO) after endovascular aneurysm repair (EVAR) is increased by severe tortuosity of the iliac artery. A bare metal stent (BMS) may protect LGO, according to the hypothesis of this single-center retrospective analysis. All patients undergoing elective EVAR with a bifurcated stent graft between January 2012 and June 2022 were included in this cohort study. Patients demonstrating significant tortuosity at the iliac angle were incorporated into this study and classified into two groups: group A comprised those who received a BMS. In contrast, group B consisted of those who did not receive a BMS. The primary outcomes were the incidence of limb occlusion and technical success during the follow-up period. However, secondary outcomes included perioperative mortality, external iliac angioplasty, and crossed-limb techniques. This study has been reported as being in line with the STROCSS criteria. A total of 157 patients (mean age = 71.6 ± 8 years) with infrarenal abdominal aortic aneurysms were enrolled. In total, 50 individuals were included in group A, while 107 were in group B. Overall technical success was 100%, and only one (2%) patient from group A and 17 (15%) from group B suffered from limb occlusion during follow-up (p < 0.05). At a mean follow-up imaging duration of 28.7 ± 23.6 months (range 1-124), the estimated primary limb patency at 2 years was 98% for the BMS group and 84% for the non-BMS group (p < 0.05). There were no changes in perioperative mortality or crossed-limb procedures between the BMS and non-BMS groups. Nonetheless, there were disparities in external iliac angioplasty between the two groups during the follow-up period (p < 0.05). Deploying a BMS inside the iliac artery to prevent or treat limb occlusion is a safe and effective strategy, with clear prolonged outcomes concerning patency and re-interventions.

Monocyte to high-density lipoprotein cholesterol ratio predicts restenosis of drug-eluting stents in patients with unstable angina pectoris

Several studies have shown that the monocyte count to high-density lipoprotein cholesterol ratio (MHR) serves as a predictive marker for in-stent restenosis (ISR) of bare-metal stents (BMSs). However, the ability of the MHR to predict ISR in patients with drug-eluting stents (DESs) remains uncertain. This study aimed to investigate the predictive value of the MHR for ISR in patients with unstable angina pectoris who have undergone primary DES implantation. A total of 474 consecutive patients with unstable angina pectoris who underwent successful DES-based percutaneous coronary intervention (PCI) from 01-12-2014 to 01-12-2022 were enrolled in the study. Patients were divided into the ISR group and the non-ISR group on the basis of the follow-up results of coronary angiography. The demographic and clinical characteristics of the patients were documented. The MHR was calculated via the following formula: . Multivariate logistic regression models were developed to evaluate the predictive value of the MHR for DES-ISR. The baseline MHR was notably greater in the ISR group than in the non-ISR group (P < 0.001). After adjusting for confounding factors, the MHR emerged as an independent predictor of ISR (OR = 1.244; 95%CI 1.171–1.321). Receiver operating characteristic (ROC) curve analysis revealed that MHR for predicting ISR had an AUC of 0.752 (95% CI 0.708–0.796). For a MHR > 7.32, the sensitivity was estimated to be 59.8% (95% CI 47.2-66.5%) and the specificity was 81.2% (95% CI 71.2-86.4%). Including the MHR in the predictive model for ISR improved the area under the curve (0.698 vs. 0.782, P < 0.001), categorical net reclassification improvement (0.703; 95%CI 0.536–0.871), and integrated discrimination improvement (0.121; 95%CI 0.092–0.151). The MHR can be used to predict DES-ISR in patients with unstable angina pectoris, indicating that the MHR may serve as a valuable marker for risk stratification and prognosis in individuals undergoing DES implantation.

Device-Related Patient Outcomes for Coronary Stents: A MAUDE Database Analysis

The growing prevalence of coronary artery diseases in the US corresponds to the high use of minimally invasive techniques that require coronary stents. Although extensive research is available on the long-term consequences of the 3 stent options – bare-metal stents (BMS), drug-eluting stents (DES), and bioresorbable drug-eluting stents (BVS), a knowledge gap exists in the longitudinal monitoring of patient outcomes due to device-related causes. Therefore, our study examines the device-related patient outcome and the relative performance for BMS, DES, and BVS. Data on 3 device outcomes (deaths, injuries, and malfunction) for each device was obtained from the January 2011 to February 2020 Manufacturer and User Facility Device Experience (MAUDE) database. Statistical visualizations and analysis were used to identify trends and significant differences between data groups. Of a total of 68,618 adverse event reports, DES, BMS, and BVS each accounted for 88.5%, 10.2%, and 1.25% of the cases, respectively. Device malfunctions were the most reported event (47.2%), followed by injuries (44.1%) and deaths (8.66%). Over time, BMS malfunction rates showed a steady decrease (R = -0.87), while DES malfunction rates increased significantly (R = 0.79). An inversely proportional relationship between DES injuries and malfunctions was observed, suggesting a possible shift in reporting categories. The increase in DES malfunctions was 4 times greater than the decrease in BMS malfunctions. Approximately 7% of reported adverse events were classified as misreported, with most involving DES. These results suggest 2 plausible interpretations: 1) reporting categorization for devices shifted from injuries to malfunction, and 2) stents choice is transitioning from BMS to DES. Our findings also highlight the need to improve reporting accuracy for MAUDE database data.

Evaluation of safety and efficacy of intracranial self-expanding drug-eluting stents for symptomatic intracranial atherosclerotic stenosis: a prospective, multicentre, randomised controlled, superiority clinical trial protocol

BackgroundIn-stent restenosis (ISR) is a crucial factor that affects the long-term efficacy of intracranial bare metal stent (BMS) implantation for intracranial atherosclerotic stenosis (ICAS). Patients with intracranial ISR are at...

Transjugular Intrahepatic Portosystemic Shunt (TIPS) Check and Revision in a Freestanding Outpatient Facility: Safety and Efficacy.

Aim This study aims to evaluate the safety and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) check and revision procedures performed in a freestanding interventional radiology (IR) outpatient facility. Methodology A total of 40 patients (male 31:female 9, median age 60 years old) underwent a TIPS check and/or revision at a freestanding IR outpatient facility between 2009 and 2017.Procedures were performed using a mobile C-arm unit under intravenous (IV) moderate sedation, with the patient discharged home on the same day. The decision to perform a TIPS check was based on abnormal surveillance ultrasound findings or the recurrence of portal hypertension symptoms. TIPS were revised if the patient was found to have angiographic stenosis, elevated portosystemic gradients, or recurrent symptoms. TIPS were revised with balloon angioplasty and/or bare metal stent placement. Results Revision was attempted in 34 cases, and 6 were found to not require a revision. The average time to revision was 19 months (range 0.6-99 months). Of the 40 patients, 24 (60%) underwent a TIPS check and/or revision due to findings from surveillance ultrasound, while 16 (40%) underwent a check or revision due to a recurrence of symptoms. Of the 34 TIPS revisions, 28 (83%) involved angioplasty alone, 5 (15%) were stent-assisted, and 1 failed due to unsuccessful cannulation. The overall technical success rate for performing the revisions was 94% (32/34). The one-year patency rate was approximately 57%. The mean fluoroscopy time was 16.1 minutes (range: 3.7-52.5 minutes). Post-procedural recovery time was minimal, averaging one to two hours. No major complications were observed (0%, 0/40). One patient (2.5%, 1/40) experienced a minor complication (access site hematoma), and two patients were hospitalized within 30 days for reasons unrelated to the procedure. Conclusions TIPS revision can be performed successfully and safely in an outpatient facility.

Abstract 4134630: Focal Delivery of Antiplatelet Therapy to Prevent Post-Stent Bleeding in High-Risk Patients

Background: Over 3 million percutaneous coronary interventions (PCI) are performed yearly to treat coronary artery stenosis. Stent thrombosis is a catastrophic complication associated with high morbidity and mortality, and its prevention requires the use of prolonged dual antiplatelet therapy (DAPT), which increases bleeding risk. Within the first 30 days after PCI, the mortality of DAPT-associated major bleeding is on par with recurrent myocardial infarction. Research question: No stent system that provides focal antiplatelet activity to prevent stent thrombosis exists, eliminating the need for systemic DAPT and subsequent bleeding risk. Aim: To address this unmet need, we have developed such a stent, termed “the ticagrelor coated stent” (TCS). Methods: Self-assembled monolayers (SAMs) of 12-aminododecylphosphonic acid (ADPA) were formed on cobalt-chromium stents. The amine tail group of ADPA was used to link the ticagrelor molecule through a Mitsunobu reaction and confirmed via infrared spectroscopy. Coating uniformity was validated via atomic force microscopy. In an ex-vivo porcine arterio-venous fistula model, the ticagrelor-coated stents (TCS) were placed in alternating series adjacent to uncoated bare metal stents (BMS). Similarly, TCS and everolimus-eluting stents were placed in the porcine left circumflex arteries for acute (7 days) and chronic (35 days) studies. Results: ( Figure 1 ): Grossly, no thrombus was seen on the TCS compared to the BMS. Platelet and micro-thrombi adherence were significantly reduced on TCS. Notably, inflammation, measured by neutrophil and monocyte adherence, was also reduced by approximately 10-fold on the TCS vs the BMS. Angiography, optical coherence tomography (OCT), and histopathology results show the TCS widely patent without systemic DAPT. Conclusion: These findings show that TCS prevents stent thrombosis through focal anti-platelet action and may reduce the bleeding risk associated with prolonged use of systemic DAPT. Long-term safety and efficacy studies are underway.

Abstract 4124070: Dual-action Nanomatrix Coated Stent for Improving Endothelialization while Suppressing Restenosis and Inflammation

Introduction: The most common cause of cardiovascular disease (CVD) is atherosclerosis. The progression of atherosclerosis is characterized by endothelial cell dysfunction, proliferation of smooth muscle cell proliferation, and plaques which lead to progressive arterial stenosis. Bare metal stents (BMS) were developed to hinder stenosis, but re-stenosis has been observed following deployment. Drug-eluting stents (DES) have been developed to mitigate this, by releasing anti-proliferative drugs to suppress smooth muscle cell proliferation. However, these drugs also suppress endothelial growth. To address this, we are developing and evaluating a dual action nanomatrix coated stent comprised of a nitric oxide (NO) releasing peptide amphiphile (PA) and everolimus-encapsulated liposomes to improve endothelial proliferation and suppressing smooth muscle cell proliferation and inflammation. Materials and Methods: The nanomatrix coating contains a PA generated via solid phase peptide synthesis consisting of a nitric oxide donor and a cell adhesive ligand. The everolimus-encapsulated liposomes were prepared with DPPC, DOTAP, DSPE-PEG, and cholesterol via thin film rehydration, followed by encapsulation with everolimus. TEM was performed on liposomes to assess their stability. The release kinetics were evaluated via UV-vis of samples containing released everolimus. To evaluate the dual effect of the nanomatrix coating on metabolism, NO and everolimus were used to treat endothelial and smooth muscle cells, and an MTT assay was done. Results and Discussion: TEM showed that liposomes maintained stability over time. It was found that 60% of everolimus was released by day 30. The MTT assay showed that NO with everolimus increased endothelial cell metabolic activity and maintained or lowered smooth muscle cell activity compared to everolimus alone. Conclusions: Everolimus-encapsulated liposomes have potential as an effective delivery method of everolimus. NO and everolimus have a synergistic effect of improving endothelial function and suppressing smooth muscle cells.