Stent Type Research Articles

Aspirin exposure and its association with metal stent patency in malignant distal biliary obstruction: a large international multicenter propensity score–matched study

Background and AimsStent dysfunction is common following endoscopic retrograde cholangiopancreatography (ERCP) with self-expanding metal stent (SEMS) insertion in malignant distal biliary obstruction (MDBO). Chronic aspirin exposure (ASA-E) has been previously shown to potentially decrease this risk. We aim to further ascertain the protective effect of ASA and to identify other predictors of stent dysfunction. MethodMulticenter retrospective cohort study (9 Canada and 1 US). MDBO who underwent ERCP-SEMS between 01/2014-12/2019 were included and divided into two cohorts: ASA-E and ASA unexposed (ASA-U). Propensity score-matching (PSM) was performed to limit selection bias. Matched variables included: age, sex, tumor stage, and type of metal stent. The primary outcome was the hazard rate of stent dysfunction. A multivariable Cox proportional hazards model was used to identify independent predictors of stent dysfunction. Results1,396 patients were assessed. Following PSM a total of 496 patients were analyzed (248 ASA-E, 248 ASA-U). ERCP-SEMS was associated with high clinical success of 82.2% in ASA-E and 81.2% in ASA-U, p=0.80. A total of 184 patients had stent dysfunction wth a mean stent patency time of 229.9 ± 306.2 days and 245.4 ± 241.4 days in ASA-E and ASA-U, resepectively (p=0.52). On multivariable analysis, ASA-E did not protect against stent dysfunction with a hazard ratio of 1.25 (95% confidence interval, CI: 0.96; 1.63). Pancreatic cancer etiology (HR 1.36, 95% CI:1.15-1.61) predicted stent dysfunction while cancer therapy was protective (HR 0.73, 95% CI: 0.55; 0.96). The use of chronic ASA was not associated with an increased risk for adverse events including bleeding, post-ERCP pancreatitis, and perforation. ConclusionIn this large, multicenter study utilizing propensity score-matching, chronic exposure to ASA did not protect against stent dysfunction in MDBO. Instead, the analysis revealed that the etiology of pancreatic cancer was an independent predictor of stent dysfunction while cancer therapy was protective.

Balloon-expandable cheatham-platinum stents versus self-expandable nitinol stents in coarctation of aorta: 3-year outcome of a randomized clinical trial

Abstract Introduction Although stenting showed early promising results in the treatment of patients with coarctation of aorta (CoA), its long-term benefit it is scarcely studied. Previously, we have shown, balloon-expandable stents (BES) and self-expandable (SES) stents were both effective and safe during 12-month follow up in the treatment of native CoA. Purpose To report the 3-year outcomes of BES versus SES stents in patients with native CoA. Methods Adult patients with de novo native CoA were randomized into Cheatham-platinum BES and uncovered nitinol SES groups in this parallel-group, open-label, blinded endpoint randomized clinical trial. All randomized patients were assigned to the 3-year structural follow up, consisted of clinical examination (including blood pressure measurement), exercise test for detecting masked hypertension, aortic CT angiography and transthoracic echocardiography. The 3-year incidence of recoarctation of aorta, thoracic aortic aneurysm formation, and residual hypertension were reported as the main long-term outcomes. Results Of the 92 patients initially randomized, 71 patients were participated in 3-year structural follow-up (Figure 1). Residual hypertension, defined as a persistent need for antihypertensive drugs at 3-year were significantly higher in BES (25 (71.4%) versus 17 (47.2%) patients (risk ratio (RR), 1.51, 95% confidence interval (CI), [1.00 to 2.26], p= 0.03) (Figure 2). Apart from five patients diagnosed with recoarctation during the first year of follow-up, no new cases of recoarctation were detected between 1 to 3-year follow up. Of note 2 of 3 patients with recorctation in the BES group, needed a second reintervention during the long-term follow up. Thoracic aortic aneurysm formation was not different in both stent types (4 (11.4%) versus 2 (5.6%) patients (RR, 2.06, 95% CI, [0.40 to 10.52], p= 0.37). Three-year median differences of ascending aorta and aortic arch were not different between the two groups. Conclusion Overall, both BES and SES were safe and effective in the long-term follow up. The rate of recoarctation was low even in the long-term follow up, which were safely reintervene. A hypothesis-generating difference were detected between two types of stents on residual hypertension which needs to be verified in larger studies.Baseline Characteristics and Study Flow3-year Outcomes

Association of inflammatory activation with acute stent thrombosis

Abstract Background Acute stent thrombosis (ST) is a rare but deleterious event. Acute infection and inflammation may lead to activation of the coagulation system and of platelets. Coronary angiography with stent implantation is often deferred because of increased inflammatory markers. Purpose The aim of this study was to investigate whether an acute inflammatory state is associated with increased risk of early stent thrombosis. Methods Within a prospective single-center registry, the association between pre-procedural acute inflammatory activation, defined as C-reactive protein (CRP) plasma levels >5mg/dL or leukocytes >12 G/L, and occurrence of early stent thrombosis within 30 days after PCI was evaluated. Results We included 11327 patients that underwent coronary stenting. 3964 (35%) were treated for acute coronary syndrome (ACS) and 7363 (65%) had chronic coronary artery disease. The number of definite early ST within 30 days was 91 (0.8 %). Leukocyte count and plasma levels of C-reactive protein (CRP) were available in 6880 patients (87 patients with ST). 1715 patients showed signs of an acute inflammatory state as defined by a leukocyte count > 12 G/L or plasma levels of CRP > 5mg/dL. Stent implantation in patients with acute inflammation was associated with significant increased risk for ST (HR 3.01; p<0.0000001) independent of age, gender, kidney function, number and type of stents, presence of multivessel disease, choice of P2Y12 inhibitor and clinical presentation. This was the case in patients with (HR 2.48; p<0.001) and without acute coronary syndromes (HR 3.59; p<0.001). The incidence of ST in patients with ACS with and without signs of inflammation was 2.7% vs. 1.1% (p<0.001) and in patients with chronic coronary artery disease with and without inflammation was 2.3% vs 0.7% (p<0.001) Conclusions An acute inflammatory state as defined by a leukocyte count > 12 G/L or plasma levels of CRP > 5mg/dL at time of stent implantation was associated with a significant increased risk of acute ST. In particular in patients with chronic coronary artery disease acute inflammatory activation should lead to a deferral of elective interventions. In patients with ACS and increased inflammatory parameters, in which acute PCI is mandatory, future studies are needed, whether more intensive therapy could reduce risk of early ST in this particular high-risk cohort.

C-reactive protein levels and coronary in-stent restenosis: A systematic review and meta-analysis

Abstract Background C-reactive protein (CRP) is an inflammatory biomarker and has been implicated in the pathogenesis of atherosclerotic lesion formation, plaque rupture, and coronary thrombosis. Its relationship to adverse angiographic outcomes after coronary stenting however remains uncertain. Purpose We aimed to test the association of baseline CRP levels with the incidence of coronary in-stent restenosis (ISR) using a systematic review and meta-analysis. Methods Relevant published studies were identified following a US National Institutes of Health (PubMed), EMBASE, MEDLINE, Scopus and Web of Knowledge databases search, until 31st October 2022. Selected studies had to be/have (i) original research with an angiographically determined ISR and an angiographically or clinically determined no-ISR group, and (ii) CRP levels measured before index stenting for both groups. Mean difference in CRP levels with its 95%CI between ISR and no-ISR was ascertained for each included study. Pooled standard mean difference (SMD) and its 95%CI was derived after pooling study level results using random effects employing a Z test. Begg’s funnel plots and Egger’s test were used for publication bias assessment. Results Amongst total of 1,009 unique results, 497 full-text articles were assessed for eligibility, 461 were excluded for a variety of reasons, which left 36 articles with 37 different studies (Nst= 37), with a total sample of 10,577 (2,122 ISR cases / 8,455 controls), to be included for quantitative synthesis. Complete study flow is depicted in Figure 1. ISR group had higher pooled CRP levels (Nst= 37, SMD= 0.50, 95% CI= 0.33, 0.67 mg/L, p< 0.00001) as compared to no-ISR group. Sensitivity analysis found no instance of significant alteration from the original results. No evidence of publication bias was detected either visually by the Begg’s funnel plots or the Egger’s test (p= 0.07). Analysis was repeated after subgroup stratification of the included studies according to study design, stent type, assay type, ancestry, presentation diagnosis, and data type. Important findings identified by the subgroup analysis were the significant differences in CRP levels between ISR and no-ISR, amongst Middle Easterners (Nst= 10, SMD 0.63, 95%CI 0.33, 0.93 mg/L, p< 0.0001) and Asians (Nst= 18, SMD 0.71, 95%CI 0.46, 0.96 mg/L, p= 0.00001), however not amongst Europeans (Nst= 9, SMD -0.11, 95%CI -0.43, 0.21 mg/L, p= 0.50). Results obtained for other subgroups however remained consistent and showed significant positive associations. (Figure 2.) Conclusions The present systematic review and meta-analysis indicates a positive association of higher baseline CRP values with the incidence of angiographically confirmed ISR. In subgroup analysis there was no evidence of association amongst Europeans, in contrast to significant associations seen amongst rest of the ancestries. These results warrant further validation in dedicated large cohorts, ideally in a prospective setting.Figure 1.Figure 2.

Intracoronary imaging guided percutaneous coronary intervention of stent restenosis: does it make a difference?

Abstract Background In-stent restenosis (ISR) remains the most common cause of stent failure after percutaneous coronary intervention (PCI). Compared to coronary angiography (CA), intracoronary imaging (ICI) provides a more accurate and detailed characterization of the degree of ISR and may help identify the underlying pathophysiological mechanism. Although recommended in the European guidelines, the impact of ICI in clinical outcomes in ISR is still under discussion. Purpose Our study aimed to analyze and compare clinical outcomes between CA PCI (group 1 - G1) and ICI-guided PCI (Intravascular ultrasound (IVUS) or optical coherence tomography (OCT)) (group 2 - G2). Methods We performed a retrospective single-center review of all consecutive patients with ISR treated in our center from September 2014 to January 2022. Patients with acute stent thrombosis were excluded. Primary endpoint was defined as death by all causes and secondary endpoint as a composite of cardiovascular (CV) mortality, culprit ISR PCI and ischemic stroke. Results 130 patients were included (mean age 66.23 ± 11.832 years, 77.7% male and mean follow-up period (FUP) 48.70 ± 27.356 months). Mean left ventricular ejection fraction was 50.19 ± 10.509%, 66.2% had dyslipidemia, 45.3% hypertension, 38.5% diabetes, 36.2% heart failure and 29.2% previous multivessel PCI. A total of 142 ISR lesions from 136 arteries were treated and ICI was used in 37 (28.5%) patients (IVUS in 16 (12.3%) and OCT in 21 (16.2%)). The ISR coronary segment and pattern is described in Table 1. The mechanism for ISR was identified in 23 lesions. The most common indication for coronary angiography was stable angina in 34.6% and NSTEMI in 31.5% and ISR was the culprit in 128 (98.5%) of the cases. The groups were well matched regarding baseline characteristics and comorbidities. PCI strategy was more often drug-eluting stenting (DES) vs drug-coated balloon (DCB) in group 2 (DES 18.3% vs 51.4% and DCB 81.7% vs 43.2% in G1 and G2 respectively). And, as expected, treatment of bifurcation lesions was more frequent in group 2 (9.7% G1 vs 30.6% G2). During the FUP there were 10 (7.7%) CV deaths and 19 (14.6%) non-CV deaths (19 in G1 and 0 in G2). The composite outcome of CV mortality, ischemic stroke and culprit ISR PCI occurred in 19 (20.2%) patients in G1 and 1 (2.7%) patient in G2. The use of ICI was associated with reduced all-cause mortality (HR=0.667 [95% CI 0.584-0.760], p=0.011) and reduced composite outcome (B (95%CI): -0.251 (-0.455 - -0.046), p=0.017). No difference between IVUS or OCT was found. The PCI strategy (DES vs DCB), stent type, length or diameter were not predictors of outcomes. Conclusion In IRS PCI, the use of ICI compared to standard of care CA was associated with a reduction in all-cause mortality and composite outcome of CV mortality, culprit ISR PCI and ischemic stroke. The strategy of PCI differed with DES being used more frequently than DCB. No difference between IVUS or OCT was found.

Abstract 15381: Clinical Outcomes of Post-Drug-Coated Balloon Angioplasty Dissection in Large De-Novo Coronary Artery Disease

Introduction: Drug-coated balloon (DCB) may be an alternative to stents in the treatment of large native coronary artery disease. However, the complications of acute elastic recoil and coronary dissections confine the practical application of DCB. Little is known about the clinical outcomes of different types of dissection after DCB angioplasty with or without stenting. Aims: This study sought to investigate the clinical outcomes of post-DCB dissection in large de novo coronary artery disease. Methods: This was a retrospective observational study. A consecutive series of patients with large native coronary artery disease (reference diameter ≥ 3.0 mm) who occurred coronary dissections after the treatment of DCB angioplasty were included. These patients were divided into stented groups and non-stented groups depending on whether bail-out stents were employed. Post-angioplasty coronary artery dissections were classified into type A-F. The cumulative incidence of major adverse cardiac events (MACE) was compared between the two groups. Results: Between March 2017 and October 2022, 676 patients with large de novo coronary artery disease developed post-DCB angioplasty dissection, 554 of which treated with DCB only, 122 of which underwent bail-out stent implantation. These dissections were type A (60.5%), B (30.9%), C (6.5%), D (1.9%) and F (0.1%), respectively. During a mean follow-up of 1 year, MACE occurred in 60 patients (9 in the stented group and 51 in the non-stented group; 7.4% vs. 9.2%; p=0.522). For type B dissection, the rate of MACE was similar in the stented group than that in the non-stented group (11.1% vs. 8.2%; p=0.502). For type C dissection, the rate of MACE was numerically higher in the non-stented group than that in the stented group (9.5% vs. 0%; p=0.222). Conclusions: For post-DCB angioplasty dissection in large de-novo coronary artery disease, type B dissection requires no bail-out stent implantation and type C dissection deserves further investigation.

Five-Year Efficacy and Safety of TiNO-Coated Stents Versus Drug-Eluting Stents in Acute Coronary Syndrome: A Meta-Analysis.

(1) Background: Percutaneous coronary interventions (PCI) in patients with acute coronary syndrome (ACS) are performed with titanium-nitride-oxide-coated stents (TiNOSs) or drug-eluting stents (DESs). The initial completion of this prospective systematic literature review (SLR) of prospective randomized controlled trials (RCTs) showed that TiNOSs are non-inferior to DESs in major adverse cardiac event (MACE) rates and present a lower risk of recurrent myocardial infarction (MI) at 1-year follow-up. This iteration of the SLR protocol performs the critical assessment of 5-year follow-up outcomes with clinical validity and generalizability assessments. (2) Methods: The previously described SLR and meta-analysis protocol, per PRISMA, Cochrane methods, and GRADE, was applied to 5-year follow-up outcomes. (3) Results: Three RCTs were eligible, comprising 1620 patients with TiNOS vs. 1123 with DES. The pooled risk ratios (RRs) and 95% confidence intervals were MACE 0.82 [0.68, 0.99], MI 0.58 [0.44, 0.78], cardiac death (CD) 0.46 [0.28, 0.76], ischemia-driven target lesion revascularization (TLR) 1.03 [0.79, 1.33], probable or definite stent thrombosis (ST) 0.32 [0.21, 0.59], and all-cause mortality (TD) 0.84 [0.63, 1.12]. The evidence certainty was high in MACE, CD, MI, and ST, and moderate in TLR and TD. (4) Conclusions: TiNOSs in ACS at 5-year follow-up appear safer than DESs and equally efficacious. The pooled RRs stratified by clinical presentation and stent type will be required to test this meta-analysis's clinical validity and generalize its results to patient populations with varying proportions of clinical presentations and DES options.

Abstract 043: Intra‐cranial Rescue stenting in patients with incomplete perfusion following mechanical thrombectomy;a systemic review and meta‐analysis.

Introduction Incomplete reperfusion following Mechanical Thrombectomy (MT) ranges from 12–34% and patients with Intracranial atherosclerotic (ICAS) occlusions are disproportionally affected.(1, 2)These patients are also more likely to experience poor functional outcomes. (3) Rescue stenting (RS) in these patients has shown promising rates of recanalization and better outcomes in preliminary studies. In our systemic review and meta‐analysis, we included Sixteen dual arm and seven single arm studies in order to study recanalization rate and compare outcomes following rescue stenting in patients with incomplete reperfusion compared to those managed conservatively (no‐RS).(4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)(20, 21, 22, 23, 24, 25, 26) Methods Our study was performed according to the preferred reporting items for systematic review and meta‐analysis (PRISMA) guidelines.(27) We incorporated studies that included participants, aged 18 years or older, and met the following criteria: (1) participants with ischemic stroke with Intracranial Atherosclerotic Stenosis (ICAS) who underwent at least one attempt of MT and had incomplete perfusion after the procedure (2) participants who received rescue stenting after MT with incomplete reperfusion, with no restrictions on the type of stents or stenting procedure used; (3) both observational studies (case series, cohort studies) and experimental designs (randomized controlled trials) were considered; (4) the control group consisted of patients incomplete reperfusion following MT but did not received no rescue stenting and were conservatively managed. We reported the recanalization rate in patients undergoing MT and compared the outcomes between the RS and no‐RS groups; MRS ≤ 2 at 90 days, Mortality at 90 days, Symptomatic Intra cranial Hemorrhage (sICH), Any Intracranial Hemorrhage (ICH), vessel dissection and vessel perforation Results Patients who underwent stenting experienced recanalization rate of 84% (95% CI: 79.0 – 88.1). They also had significantly higher odds of a better functional outcome (MRS ≤ 2 at 90 days) at 3 months compared to the no‐RS group (OR 2.70 [95% CI: 1.89 ‐ 3.86]). Odds of sICH (OR 0.92 [95% CI: 0.62 ‐ 1.36]) and any ICH (OR: 0.64 [95% CI 0.40 ‐ 1.03]) were lower but insignificant in the RS group. Odds of mortality at 90 days were significantly lower in the RS group(OR 0.59 [95% CI: 0.42 ‐ 0.83]). No significant difference in Odds of Vessel dissection (OR 1.22 [95% CI: 0.19 ‐ 8.07]) or vessel perforation (OR 0.40 [ 95% CI: 0.10 ‐ 1.61]) between the two groups was noted. Conclusion Out meta‐analysis which included the most recent studies indicates that rescue setting after mechanical thrombectomy for large artery intracranial atherosclerosis with incomplete perfusion or with residual stenosis (>50 percent) is associated with better clinical outcomes and indicates lower mortality rate and associated complications. Therefore, rescue stenting can be considered as a safe and viable option in these patients.

3D printed auxetic stents with re-entrant and chiral topologies

The mechanical performance of the medical stent is crucial and of key significance to the dependability and reliability of the stent-plaque-artery system. In this study, an auxetic stent, namely, re-entrant chiral auxetic (RCA) is proposed. Two types of stent (RCA-X and RCA-Y) are proposed. The RCA stents are designed through a periodic distribution of two dimensional (2D) RCA cells along both the circumferential and axial directions. A set of polyimide specimens were 3d printed using Multi-Jet Fusion process. The compressive properties of the 3d printed stents were experimentally examined, while the tensile properties were numerically investigated. Results showed that the RCA-X stent revealed a remarkable radial expansion (i.e. auxetic features) of approximately 50% while the RCA-Y stent showed radial expansion of 16.7%. Despite the auxetic features of the compressed stents, asymmetric deformation patterns were resulted in the case of the RCA-X while uniform patterns were resulted in the case of the RCA-Y. The FE models were further employed to examined the effects of number of unit cells along the circumferential direction on the auxetic features. The auxetic features of the developed stents could be controlled by adjusting the geometric parameters of the RCA’s cell and number of cells along the circumferential direction. The promising properties of the RCA stents might sheds the light on the design auxetic stents for practical clinical applications.

A novel noble metal stent coating reduces in vitro platelet activation and acute in vivo thrombosis formation: a blinded study

Inherent to any stenting procedure is the prescription of dual antiplatelet therapy (DAPT) to reduce the platelet response. Clinical guidelines recommend 6–12 months of DAPT, depending on stent type, clinical picture and patient factors. Our hypothesis is that a nanostructured noble metal coating has the potential to reduce protein deposition and platelet activation. These effects would reduce subsequent thrombo-inflammatory reactions, potentially mitigating the need for an extensive DAPT in the acute phase. Here, a noble metal nanostructure coating on stents is investigated. Twelve pigs underwent endovascular implantation of coated and non-coated stents for paired comparisons in a blinded study design. The non-coated control stent was placed at the contralateral corresponding artery. Volumetric analysis of angiographic data, performed by a treatment blinded assessor, demonstrated a significant thrombus reduction for one of the coatings compared to control. This effect was already seen one hour after implantation. This finding was supported by in vitro data showing a significant reduction of coagulation activation in the coated group. This novel coating shows promise as an implant material addition and could potentially decrease the need for DAPT in the early phases of stent implementation.

Outcomes of covered vs bare metal stents for the treatment of aortoiliac occlusive disease

ObjectiveWe retrospectively compared the clinical outcomes of self-expanding covered stents (CSs) and bare metal stents (BMSs) in the treatment of aortoiliac occlusive disease (AIOD) at a single center between 2016 and 2022. MethodsAll patients with AIOD receiving endovascular therapy at a single center from January 2016 to October 2022 were continuously analyzed, including patients with lesions of all classes according to the Trans-Atlantic Inter-Society Consensus II (TASC-II). Relevant clinical and baseline data were collected, and propensity score matching was performed to compare CSs and BMSs in terms of baseline characteristics, surgical factors, 30-day outcomes, 5-year primary patency, and limb salvage. The follow-up results were analyzed by Kaplan-Meier curves. Cox proportional hazard models were used to identify predictors of primary patency. ResultsA total of 209 patients with AIOD were enrolled in the study, including 135 patients (64.6%) in the CS group and 74 patients (35.4%) in the BMS group. Surgical success rates (100% vs 100%; P = 1.00), early (<30-day) mortality rates (0% vs 0%; P = 1.00), cumulative surgical complication rate (12.0% vs 8.0%; P = .891), 5-year primary patency rate (83.4% vs 86.9%; P = .330), secondary patency rate (96% vs 100%; P = .570), and limb salvage rate (100% vs 100%; P = 1.00) did not exhibit significant differences between the two groups. Patients in the CS group had a lower preoperative ankle-brachial index (0.48 ± 0.26 vs 0.52 ± 0.19; P = .032), more cases of complex AIOD (especially TASC D) (47.4% vs 9.5%; P < .001), more chronic total occlusive lesions (77.0% vs 31.1%; P < .001), and more severe calcification (20.7% vs 14.9%; P < .036). After propensity score matching, 50 patients (25 with CS and 25 with BMS) were selected. The results showed that only severe calcification (32.0% vs 8.0%; P = .034) and ankle-brachial index increase (0.45 ± 0.15 vs 0.41 ± 0.22; P = .038) were significantly different between the groups. In terms of surgical factors, patients in the CS group had more use of bilateral femoral or combined brachial artery percutaneous access (60.0% vs 12.0%; P < .001), more number of stents used (2.3 ± 1.2 vs 1.3 ± 0.7; P < .001), longer mean stent length (9.3 ± 3.3 vs 5.8 ± 2.6 cm; P < .001), and more catheter-directed thrombolysis treatment (32.0% vs 4.0%; P = .009). Multivariate Cox survival analysis showed that severe calcification (hazard ratio, 1.32; 95% confidence interval, 1.04-1.85; P = .048) was the only independent predictor of the primary patency rate. ConclusionsAll patients with AIOD who underwent endovascular therapy were included and achieved good outcomes with both CSs and BMSs. The influence of confounding factors in the two groups was minimized by propensity score matching, and the 5-year patency rates were generally similar in the unmatched and matched cohorts. Postoperative hemodynamic improvement was more obvious in patients in the CS group. For more complex lesions, CS is recommended to be preferred. Especially for severe calcification lesions, which is the only independent predictor of primary patency, CS showed obvious advantages. Further studies with more samples are needed to investigate the role of stent types in AIOD treatment.

Biological response of degradation products of PEO-modified magnesium on vascular tissue cells, hemocompatibility and its influence on the inflammatory response

Cardiovascular stenting is the most widely used therapy to treat coronary artery disease caused by partial or total obstruction of the artery due to atherosclerotic plaque formation, with potentially fatal effects. There are different types of stents: bare metal stents, drug-eluting stents, bioabsorbable stents and dual therapy stents. However, they can lead to long-term complications, such as in-stent restenosis and late thrombosis. To reduce these adverse effects, research has focused on biodegradable metallic stents, since they retain the mechanical properties necessary to contain the injured artery while it is being repaired and, once their function has been fulfilled, the stent degrades without altering the system or compromising the patient's health. In this work we have evaluated the biological response of the degradation products of a bare Mg based biomaterial surface-modified by the plasma electrolytic oxidation (PEO) method on vascular tissue cells, hemocompatibility and inflammatory response. The results obtained are compatible with a biosafe material for future use as a cardiovascular implant, but it is necessary to continue with in vivo and mechanical properties tests to ensure and guarantee its use. Significance statementThe development of fully bioresorbable stents is a promising alternative for the management of coronary artery disease without causing long-term problems at the implantation site. In this work, the hematological and immunological biocompatibility of bare Mg modified superficially by plasma electrolytic oxidation (PEO-Mg) was evaluated by in vitro and ex vivo assays. PEO-Mg was found to be compatible with blood and immune components surrounding the implantation site with no signs of toxicity to endothelial cells, macrophages, and arterial tissue. In addition, degradation products of PEO-Mg are eliminated by phagocytosis. However, an in-depth study of the physical and mechanical properties and in vivo biocompatibility must be carried out for its future use as a biomedical implant.

Risk stratification of acute kidney injury (AKI) following ureteral stent insertion for colorectal surgery.

Ureteral stents have long been utilized during colorectal resections to assist in the identification of ureters intraoperatively and mitigate risk of ureteral injury. As these procedures have shifted toward robot-assisted laparoscopic methods, lighted stents have increasingly been used. The incidence of acute kidney injury (AKI) following bilateral ureteral stent placement has been reported to be as high as 41.9%. We sought to identify our single-institution risk and determine the extent to which age, sex, and stent type affected incidence of AKI. A retrospective analysis was performed at a single community hospital of all open and robotic-assisted laparoscopic colorectal surgeries from October 2012 to April 2022. If requested, ureteral stents were placed bilaterally by a urologist and later removed by the surgeon. Non-lighted stents used were 5 Fr whistle-tip (BARD); lighted stents were 6 Fr with a fiberoptic core (STRYKER). Kidney failure was described as a rise of creatinine to ≥ 1.5 times the preoperative value, per KDIGO guidelines. 633 consecutive colorectal surgeries were evaluated, with no stents placed in 237 cases, non-lighted stents placed in 137 cases, and lighted stents placed in 259 cases. No ureteral injuries were observed. Overall incidence of AKI for non-stented surgeries was 0.8% vs 5.8% for non-lighted stents and 5.8% for lighted stents. Patient age was the most significant factor in AKI incidence: for patients under 60, there was no statistical difference in AKI incidence for stented vs non-stented procedures (2.2% vs 1.1%). For patients over 60, the risk of AKI was 10.5% for stented vs 0.7% for non-stented. Female patients had statistically significant risk differences, with AKI incidence of 7.1% stented vs 0.0% non-stented. AKI completely resolved in all cases, regardless of cohort. In patients under age 60, the use of stents was not associated with an increased risk of AKI. For women and those over 60, stents pose a higher risk of transient AKI. Overall incidence of AKI in our larger and single-institution community hospital population was significantly lower than reported in other studies. No statistical difference was observed, overall, in AKI incidence between lighted and non-lighted stents.

Meta-analysis of outcomes from drug-eluting stent implantation in femoropopliteal arteries.

In recent years, studies of drug-eluting stent (DES) for femoropopliteal artery diseases (FPADs) have been gradually published. To explore whether this type of stent is superior to the traditional bare metal stent (BMS), we performed this study. A systematic search for randomized controlled trials (RCTs) in Excerpta Medica Database (Embase), PubMed, Web of Science (WOS), and Cochrane Library was performed on November 29, 2022. We innovatively adopted the hazard ratio (HR), the most appropriate indicator, as a measure of the outcomes that fall under the category of time-to-event data. The HRs was extracted directly or indirectly. Then, the meta-analyses using random effects model were performed. The bias risks of included papers were assessed by the Cochrane Risk of Bias 2.0 tool. This study was registered on the PROSPER platform (CRD42023391944) and not funded. Seven RCTs involving 1,889 participants were found. After pooled analyses, we obtained results without propensity on each of the following 3 outcomes of interest: in-stent restenosis (ISR) -free survival, primary patency (PP) survival, and target lesion revascularization (TLR) -free survival (P >0.05, respectively). Because the results of pooled analyses of the other two outcomes of interest (all-cause death free survival and clinical benefit survival) had high heterogeneity both, they were not accepted by us. For FPADs, the DES has not yet demonstrated superiority or inferiority to BMS, in the ability to maintain PP, avoid ISR and TLR.

Computational modeling of low-density lipoprotein accumulation at the carotid artery bifurcation after stenting.

Restenosis typically occurs in regions of low and oscillating wall shear stress, which also favor the accumulation of atherogenic macromolecules such as low-density lipoprotein (LDL). This study aims to evaluate LDL transport and accumulation at the carotid artery bifurcation following carotid artery stenting (CAS) by means of computational simulation. The computational model consists of coupled blood flow and LDL transport, with the latter being modeled as a dilute substance dissolved in the blood and transported by the flow through a convection-diffusion transport equation. The endothelial layer was assumed to be permeable to LDL, and the hydraulic conductivity of LDL was shear-dependent. Anatomically realistic geometric models of the carotid bifurcation were built based on pre- and post-stent computed tomography (CT) scans. The influence of stent design was investigated by virtually deploying two different types of stents (open- and closed-cell stents) into the same carotid bifurcation model. Predicted LDL concentrations were compared between the post-stent carotid models and the relatively normal contralateral model reconstructed from patient-specific CT images. Our results show elevated LDL concentration in the distal section of the stent in all post-stent models, where LDL concentration is 20 times higher than that in the contralateral carotid. Compared with the open-cell stents, the closed-cell stents have larger areas exposed to high LDL concentration, suggesting an increased risk of stent restenosis. This computational approach is readily applicable to multiple patient studies and, once fully validated against follow-up data, it can help elucidate the role of stent strut design in the development of in-stent restenosis after CAS.

Comparison of trans-gastric vs trans-enteric (trans-duodenal or trans-jejunal) endoscopic ultrasound guided gallbladder drainage using lumen apposing metal stents.

Endoscopic ultrasound guided gallbladder drainage (EUS-GBD) is being increasingly used in practice (either as a bridge to cholecystectomy in high-risk patients or as destination therapy in non-surgical patients). Stents are used to create a conduit between the lumen of the gallbladder (GB) and the intestinal lumen through the gastric or enteric routes. Among the various types of stents used, cautery-enhanced lumen apposing metallic stents (LAMS) may be associated with fewer adverse events (AEs). To compare the clinical success, technical success, and rate of AEs between transgastric (TG) and trans-enteric [transduodenal (TD)/transjejunal (TJ)] approach to GB drainage. Further, we analyzed whether using cautery enhanced stents during EUS-GBD impacts the above parameters. Study was registered in PROSPERO (CRD42022319019) and comprehensive literature review was conducted. Manuscripts were reviewed for the data collection: Rate of AEs, clinical success, and technical success. Random effects model was utilized for the analysis. No statistically significant difference in clinical and technical success between the TD/TJ and TG approaches (P > 0.05) were noted. There was no statistically significant difference in the rate of AEs when comparing two-arm studies only. However, when all studies were included in the analysis difference was almost significant favoring the TD/TJ approach. When comparing cautery-enhanced LAMS with non-cautery enhanced LAMS, a statistically significant difference in the rate of AEs was observed when all the studies were included, with the rate being higher in non-cautery enhanced stents (14.0% vs 37.8%; P < 0.01). As per our study results, TD/TJ approach appears to be associated with lower rate of adverse events and comparable efficacy when compared to the TG approach for the EUS-GBD. Additionally, use of cautery-enhanced LAMS for EUS-GBD is associated with a more favorable adverse event profile compared to cold LAMS. Though the approach chosen depends on several patient and physician factors, the above findings could help in deciding the ideal drainage route when both TG and TD/TJ approaches are feasible.

Identifying the Incidence, Predictors, Outcomes, and Prevention of Stent Thrombosis (ST) in Post-percutaneous Coronary Revascularization Patients With Drug-Eluting Stents (DES): A Systematic Review.

Stent thrombosis (ST) is a rare but catastrophic event to happen to a stented coronary artery. The incidence of ST has greatly been reduced after the advent of modern drug-eluting stent (DES) implants, which have become the most preferred treatment option in the stenting category for coronary artery disease (CAD). Although the risk reduction by newer category implant provides substantial benefits, the possibility of thrombosis still exists mostly during the early stage of DES implantation. The development of ST after percutaneous coronary intervention (PCI) can be predicted by multiple factors, but advancements in early diagnostic techniques and modified stent types have greatly reduced the occurrence of this complication. Mortality, which is one of the complications of ST, is primarily influenced by patient-related factors such as incomplete treatment duration of dual antiplatelet therapy (DAPT). The duration of DAPT after DES implantation in patients with acute coronary syndrome (ACS) is determined based on individual characteristics, mainly considered in view of bleeding or ischemia risk. Risk evaluation systems like DAPT/precise-DAPT scores help tailor and personalize the duration of DAPT for each individual patient. This systematic review contains pertinent articles extracted from the PubMed database. We retrieved articles from various study categories, encompassing publications from the period spanning 2014 to 2022. Our analysis highlighted results from studies investigating different aspects contributing to ST development. The most favorable prevention option was the use of customized DAPT intervention based on patient-specific predictable factors. Several complications associated with ST were identified, including recurrent ST, major adverse cardiovascular events (MACE) encompassing all-cause mortality (including cardiac and non-cardiac mortality), cerebrovascular accidents (CVA) or transient ischemic attacks (TIA), hospitalization due to heart failure, and myocardial infarction requiring revascularization. Mortality was also observed as a significant outcome. The umbrella term of ST includes multiple causative factors. Although DES has improved patient survival rates vastly with its usage, careful risk factor assessment and required follow-up, in each individual being stented, further guarantee a more promising reduction in late adverse outcomes.

Similar success rate in proximal and distal colonic stent placement: a retrospective multi-center study

Objectives Stenting of malignant colon obstruction is used as a bridge to surgery or as an alternative to surgical colostomy in a palliative setting. Current guidelines recommend stent placement as the first line of treatment in colonic obstruction in both curative and palliative settings. However, it is unclear whether the location of the malignant obstruction influences the outcome of the stenting procedure. The goal of this study was to compare the outcomes of colonic stents between proximal and distal colonic strictures with regard to technical and clinical success and the risk of adverse events. Methods A multi-center retrospective cohort was composed of patients who underwent a colonic stent placement at two tertiary hospitals between 2013 and 2021. The technical and clinical outcome, stent type used, duration of post-procedural hospital stay and complications were noted. Results A total of 148 patients who underwent colonic stenting were identified. 41 patients underwent stent placement in the proximal colon and 107 patients underwent a distal stent placement. There was no difference in technical success (100% vs 96.3%, p = 0.209), clinical success (97.0% vs 89.6%, p = 0.199) or complications (24.4% vs 37.4%, p = 0,135) Conclusion Technical success and clinical success rates are high and do not differ between stent locations. There is no significant difference in complication rates between proximal and distal colonic stents.

Research on the Current Application Status of Magnesium Metal Stents in Human Luminal Cavities.

The human body comprises various tubular structures that have essential functions in different bodily systems. These structures are responsible for transporting food, liquids, waste, and other substances throughout the body. However, factors such as inflammation, tumors, stones, infections, or the accumulation of substances can lead to the narrowing or blockage of these tubular structures, which can impair the normal function of the corresponding organs or tissues. To address luminal obstructions, stenting is a commonly used treatment. However, to minimize complications associated with the long-term implantation of permanent stents, there is an increasing demand for biodegradable stents (BDS). Magnesium (Mg) metal is an exceptional choice for creating BDS due to its degradability, good mechanical properties, and biocompatibility. Currently, the Magmaris® coronary stents and UNITY-BTM biliary stent have obtained Conformité Européene (CE) certification. Moreover, there are several other types of stents undergoing research and development as well as clinical trials. In this review, we discuss the required degradation cycle and the specific properties (anti-inflammatory effect, antibacterial effect, etc.) of BDS in different lumen areas based on the biocompatibility and degradability of currently available magnesium-based scaffolds. We also offer potential insights into the future development of BDS.

Prognosis of coronary heart disease after percutaneous coronary intervention: a bibliometric analysis over the period 2004–2022

BackgroundAs the complexity and diversity of the percutaneous coronary intervention (PCI) are being explored and reported, burgeoning research has progressed in this field. However, there is no comprehensive analysis available on PCI-related studies published in the literature. This study aimed to analyze and visualize the changes of scientific output regarding prognosis of coronary heart disease (CHD) after PCI over the past 20 years and to reveal the knowledge domain and development trends in this field by using CiteSpace software.MethodsRelevant articles published over the period 2004–2022 were retrieved from the Web of Science Core Collection database. After manual selection, qualified documents were included and recorded with the information of their title, abstract, keyword, author, descriptor, citation, identifier, publishing year and publishing organization. We transferred the data to CiteSpace V5.8.R2 (Version 5.8.R2) to draw knowledge maps and to conduct co-occurrence analysis, cluster analysis, timeline analysis, burst term detection and citation analysis.ResultsA total of 14,699 literature records were found relating prognosis of CHD after PCI in the past 20 years (2004–2022), including 14,212 original articles and reviews, and they were published in 153 different journals. Publication production has increased annually and a total of 1182 authors, 796 institutes and 147 countries have contributed to these publications. Moreover, the most representative author was Gregg W Stone from the CardioVascular Research Foundation (CVRF) with 368 publications, whose team mainly focused on exploring the efficacy and safety of revascularization and the characteristics of susceptible population. The global productivity ranking was led by the USA with 3326 published papers, followed by Italy (n = 1355), Japan (n = 1080), China (n = 1075) and Germany (n = 937). And the keywords of these publications were “percutaneous coronary intervention” (n = 2271), “outcome” (n = 1756), “mortality” (n = 1730) and “impact” (n = 1334). Other commonly-used words were “predictor” (n = 1324), “intervention” (n = 1310), “angioplasty” (n = 1299), “risk” (n = 1144), “acute myocardial infarction” (n = 1136) and “artery disease” (n = 1098). Cluster analysis showed that 15 high connected clusters were generated with a modularity Q of 0.831 and a weighted mean silhouette of 0.9388 by applying the log-likelihood ratio algorithm, and the top 5 clusters were #0 optical coherence tomography, #1 dual antiplatelet therapy, #2 bleeding, #3 clopidogrel and #4 thrombus aspiration. Furthermore, the frontiers in the field of prognosis of CHD after PCI mainly involved “decision making”, “reperfusion”, “angioplasty”, “balloon”, “unstable angina”, “dual antiplatelet therapy”, “cardiac surgical score”, “restenosis”, “reperfusion”, “thrombolytic therapy”, etc.ConclusionsTo sum up, efficacy and safety of different types of stents, the risk factors of restenosis and thrombotic events after PCI, early risk assessment, and secondary prevention and complications of patients with CHD after PCI were research hotspots and frontier topics in the area by bibliometric analysis. The results could provide a comprehensive overview of the research hotspots and frontier topics relating prognosis of CHD after PCI, promoting a better understanding of the knowledge domain and development trends in this field during the past 20 years.