Stent Failure Research Articles

A Systematic Review on Cardiovascular Stent and Stenting Failure: Coherent Taxonomy, Performance Measures, Motivations, Open Challenges and Recommendations

Cardiovascular stenting is a mature topic but it is still being developed in the research community because of its importance. To provide worthy information about cardiovascular stenting environments and to give support to the researchers, attention must be given to understand the obtainable choices and gaps in this research field. This work aims to examine and examine the literature of each work related to the placement of cardiovascular stents, the failure of the stents and the models of stent designs to provide a good understanding through the investigation of articles published in various contextual aspects, such as motivations, open-challenges and recommendations to improve the field of stent placement. A systematic review is carried-out to map and examine the articles related to cardiovascular stents, the failure of the stents and the models of stent designs through a coherent-taxonomy used in three well-known scientific databases: ScienceDirect, IEEE Explore, and Web of Science. These databases involve literature that highlight arterial stenting. Based-on our inclusion and exception, a total of 90 articles composed the final set that offer various classes and sub-classes. The first class includes the development studies with (42/90) of experimental, computational and combined experimental and computational studies related to stent models performance and stent failure, the second class discussed studies that have been performed on stent design with (32/90), the third class is focused on the framework studies with (10/90), and the fourth class includes problems of stenting long-term with (6/90). The performance of stent designs, which is a research area that requires periodic controls, tools and procedures that could provide a stent design with good mechanical performance, reduce restenosis in the stent and increase fatigue resistance and durability. There have been numerous studies on stent performance that could promise good results in this field. The fields of research in stent designs vary, but all fields are fundamental equally. The expectation of this work could help to emphasize present research chances and, therefore, expand and make further research fields.

Prevalence, predictors, and outcomes of in-stent restenosis with calcified nodules.

Calcified nodules (CN) have been reported as being associated with stent failure including in-stent restenosis (ISR). However, there is no systematic study of this condition. We aimed to clarify the prevalence, predictors, and midterm results of ISR lesions with CN. We examined the clinical characteristics of 651 ISR lesions in patients who underwent percutaneous coronary intervention (PCI) with optical coherence tomography (OCT) between October 2008 and July 2016, and their 6- to 8-month follow-up angiography results. CN was defined as a high backscattering mass with small nodular calcium depositions which protruded into the vessel lumen. Thirty-two ISR lesions (4.9%) had CN. Multivariable analysis showed that calcified lesion (odds ratio [OR] 12.441, p<0.001), incomplete stent apposition (OR 3.228, p=0.005), haemodialysis (OR 3.633, p=0.024), and female gender (OR 3.212, p=0.036) were independently associated with ISR lesions with CN. Midterm follow-up was performed on 612 ISR lesions. Both ISR and target lesion revascularisation (TLR) rates were significantly higher in lesions with CN compared with those without CN (43.8% vs 25.0%, p=0.023; 37.5% vs 18.8%, p=0.020, respectively). However, multivariate analysis did not show the presence of CN as an independent predictor of re-TLR (OR 1.690, p=0.286). The prevalence of ISR lesions with CN was 4.9%. Calcified lesions, incomplete stent apposition, haemodialysis, and female gender are probably associated with CN formation. ISR lesions with CN may have poor midterm outcomes compared with ISR lesions without CN.

Early Australian experience with intravascular lithotripsy treatment of severe calcific coronary stenosis: IVL in acute/chronic coronary syndromes.

Calcified coronary stenoses are a serious impediment to optimal stent expansion and can lead to stent failure and catastrophic adverse outcomes. We hereby present early Australian experience with intravascular lithotripsy for the treatment of calcific lesions in acute and chronic coronary syndromes. This was a single-centre retrospective study of all patients treated with intravascular lithotripsy (IVL) between October 2019 and June 2021. Patient demographics, procedural variables, and treatment safety/efficacy outcomes were evaluated. During this period, there were 40 patients and 41 coronary lesions with IVL-assisted percutaneous coronary intervention (PCI) (70% male; mean age 72.8±9.5 years). Indications for PCI were acute coronary syndromes in 25 patients (62.5%), and stable angina in 15 patients (37.5%). Upfront IVL usage occurred in 5% of cases with the rest being bailout procedures due to suboptimal initial balloon predilatation or stent underexpansion. Angiographic success (<20% residual stenosis) occurred in 37 cases (92.5%), with mean residual stenosis of 8.25%±8.5%. Two patients experienced procedural complications (5%). IVL appears to be a safe and effective modality in modifying coronary calcium to achieve optimal stent expansion in real-world practice. This device obviates the need for more complex lesion preparation strategies such as rotational or orbital atherectomy.

Transhepatic stent placement for malignant portal vein obstruction: Long term efficacy and factors associated with stent failure

PurposeTo evaluate the long-term efficacy of transhepatic stentplacement in patients with symptomatic malignant portal vein(PV) obstruction and to identify risk factors for stent failure. MethodsFrom April 2011 to March 2021, transhepatic stent placement was attempted in 36 patients with symptomatic malignant PV obstruction: naïve (n = 20) or recurrent tumor after surgery (n = 16). Technical success, clinical outcomes, and complications were retrospectively evaluated. Thirteen relevant variables were analyzed to determine risk factors for stent failure. ResultsStent was successfully placed in all but one patient (97.2%, 35/36). Thromboaspiration (n = 9) and jejunal variceal embolization (n = 4) were performed in same session. Symptoms related to portal hypertension were resolved in 30 of the 35 patients (85.7%). There was no procedure-related major complication. During the follow-up period (median 175 days),stentfailures occurred in 8 patients (22.9%): 7 stent thromboses within 90 days and one tumor ingrowth at 715 days after stent placement. The 1-, 6-, 12-month stent patency was 94.1%, 78.2%, and 62.6%, respectively. In multivariate analysis, the presence of PV thrombosisat the time of stent placement was associated with stent failure (HR 7.22; 95% CI 1.26–41.29, p = 0.03). ConclusionTranshepatic stentplacement is a safe and effective treatment for malignant PV obstruction. However, stent failure was common (22.9%) and mostly due to early stent thrombosis. The stent failure was associated with PV thrombosis at the time of stent placement.

Effect of Evolocumab in Patients With Prior Percutaneous Coronary Intervention.

Patients with prior percutaneous coronary intervention (PCI) are at high residual risk for multiple types of coronary events within and beyond the stented lesion. This risk might be mitigated by more intensive LDL-C (low-density lipoprotein cholesterol)-lowering beyond just with statin therapy. FOURIER (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk) randomized 27 564 patients with stable atherosclerotic disease on statin to the PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitor evolocumab or placebo with a median follow-up of 2.2 years. The end points of interest were major adverse cardiovascular events (MACE; a composite of cardiovascular death, myocardial infarction, stroke, unstable angina or coronary revascularization), and major coronary events (a composite of coronary heart death, myocardial infarction, or coronary revascularization). We compared the risk of MACE and the magnitude of relative and absolute risk reductions with evolocumab in patients with and without prior PCI. Seventeen thousand seventy-three patients had prior PCI. In the placebo arm, those with prior PCI had higher rates of MACE (13.2% versus 8.3%; hazard ratio [HR]adj 1.61 [95% CI, 1.42-1.84]; P<0.0001) and major coronary events (11.5% versus 6.0%; HRadj, 1.72 [95% CI, 1.49-1.99]; P<0.0001). Relative risk reductions with evolocumab were similar in patients with and without prior PCI (MACE: HR, 0.84 [0.77-0.91] versus HR, 0.88 [0.77-1.01]; Pinteraction 0.51; major coronary events: HR, 0.82 [0.75-0.90] versus HR, 0.88 [0.75-1.04]; Pinteraction 0.42). Absolute risk reductions for MACE were 2.0% versus 0.9% (Pinteraction 0.14) and for major coronary events 2.0% versus 0.7% (Pinteraction 0.045). In those with prior PCI, the effect of evolocumab on coronary revascularization (HR, 0.76 [0.69-0.85]) was directionally consistent across types of revascularization procedures: coronary artery bypass grafting (HR, 0.71 [0.54-0.94]); any PCI (HR, 0.77 [0.69-0.86]); PCI for de novo lesions (HR, 0.76 [0.66-0.88]); and PCI for stent failure or graft lesions (HR, 0.76 [0.63-0.91]). Evolocumab reduces the risk of MACE in patients with prior PCI including the risk of coronary revascularization, with directionally consistent effects across several types of revascularization procedures, including coronary artery bypass grafting and PCI for stent or graft failure. URL: https://www. gov; Unique identifier: NCT01764633.

Age-Related Utilization of Thrombus Aspiration in Patients With ST-Segment Elevation Myocardial Infarction: Findings From the Improving Care for Cardiovascular Disease in China Project

BackgroundThere are some controversies on the utilization and benefits of thrombus aspiration in patients with ST-segment elevation myocardial infarction (STEMI). However, a few studies investigated this issue and the age-associated effects among the large population in China. Hence, we aimed to figure out the age-associated utilization and in-hospital outcomes of thrombus aspiration to improve therapeutic decisions in clinical routine.MethodsWe retrospectively recruited 13,655 eligible STEMI patients from the database of the Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome project. These subjects were allocated into primary percutaneous coronary intervention (PPCI)-only group and thrombus aspiration group after being subdivided into three age groups (G21−50, G51−75, and G76−95). After 1:1 propensity score matching for PPCI-only and thrombus aspiration groups, a total of 8,815 matched patients were enrolled for the subsequent analysis. The primary outcome was in-hospital cardiovascular death, and the key safety outcome was in-hospital stroke.ResultsWe observed that the ratio of STEMI patients undergoing thrombus aspiration to PPCI-only reduced with aging. For patients ≤ 75 years, the culprit lesion suffered from thrombus aspiration was mainly located in the left anterior descending branch, and left-ventricular ejection fraction (LVEF) was lower (G21−50: 54.9 ± 8.9 vs. 56.0 ± 8.7%, P = 0.01; G51−75: 53.9 ± 9.6 vs. 54.8 ± 9.0%, P = 0.001) and the rate of regional wall motion abnormality was higher (G21−50: 75.7 vs. 66.5%, P < 0.001; G51−75: 75.4 vs. 69.1%, P < 0.001) in the thrombus aspiration group. By contrast, for patients > 75 years, the right coronary artery was the predominant culprit lesion undergoing thrombus aspiration, LVEF (63.1 ± 10.5 vs. 53.1 ± 9.5%, P = 0.985) and the regional wall motion abnormality (79.2 vs. 74.2%, P = 0.089) were comparable between the two treatment groups. Thrombus aspiration neither reduced the in-hospital risk of cardiovascular death, all-cause death, recurrent myocardial infarction, acute stent thrombosis, heart failure, cardiogenic shock, and sudden cardiac arrest nor increased stroke risk compared with the PPCI-only group. However, after adjustment for age, thrombus aspiration presented the tendency to reduce the incidence of sudden cardiac arrest (4.9 vs. 2.5%, P = 0.06) and in-hospital cardiovascular death at 3 days (hazard ratio 0.46; 95% CI, 0.20–1.06; log-rank P = 0.08) in G76−95 group and tended to increase the incidence of heart failure in G51−75 (5.7 vs. 6.9%, P = 0.07).ConclusionThe thrombus aspiration neither significantly reduced the in-hospital incidence of major adverse cardiac events nor increased stroke risk. However, it might play a protective role in reducing in-hospital sudden cardiac arrest and increasing survival from cardiovascular death at 3 days for the elderly.

Effect of proximal optimization technique on coronary bifurcation stent failure: Insights from the multicenter randomized PROPOT trial.

We investigated the effect of proximal optimization technique (POT) on coronary bifurcation stent failure (BSF) in cross-over stenting by comparing with the kissing balloon technique (KBT) in a multicenter randomized PROPOT trial. POT is recommended due to increased certainty for optimal stent expansion and side branch (SB) wiring. We randomized 120 patients treated with crossover stenting into the POT group, which was followed by SB dilation (SBD), and the KBT group. Finally, 52 and 57 patients were analyzed by optical coherence tomography before SBD and at the final procedure, respectively. Composite BSF was defined as a maximal malapposition distance of >400 μm, or malapposed and SB-jailed strut rates of >5.95% and >21.4%, respectively. Composite BSF before SBD in the POT and KBT groups was observed in 29% and 26% of patients, respectively. In the POT group, differences in stent volumetric index between the proximal and distal bifurcation (odds ratio [OR] 60.35, 95% confidential interval [CI] 0.13-0.93, p = 0.036) and between the proximal bifurcation and bifurcation core (OR: 3.68, 95% CI: 1.01-13.40, p = 0.048) were identified as independent risk factors. Composite BSF at final in 27% and 32%, and unplanned additional procedures in 38% and 25% were observed, respectively. Composite BSF before SBD was a risk factor for the former (OR: 6.33, 95% CI: 1.10-36.50, p = 0.039) and the latter (OR: 6.43, 95% CI: 1.25-33.10, p = 0.026) in the POT group. POT did not result in a favorable trend in BSF. Insufficient expansion of the bifurcation core after POT was associated with BSF.

Long-Term Outcome of Portal Vein Stenting After Pediatric Living Donor Liver Transplantation

Portal vein (PV) stenosis is sometimes seen in pediatric living donor liver transplantation (LDLT). PV stents have been attempted in adults with persistent stenosis. However, long-term usefulness of PV stenting is unknown because stents do not expand with growth. We investigated the effect and long-term outcome of PV stenting for stenosis after pediatric LDLT. We included patients aged <18 years who underwent LDLT from 1998 to 2020 and who underwent PV stenting for stenosis. We assessed age at procedure, stent complications, and long-term outcomes. Five patients underwent PV stent placement. The median age at LDLT was 10 years (range, 0.8-18.1 years). The median interval between LDLT and stent placement was 25 months. The median age at stent placement was 16 years (range, 3-20 years). The median body weight was 38 kg (range, 13-63 kg). The median stent diameter was 8 mm. The median observation period after stent placement was 8 years. On average, body weight increased 1.6 times. One complication associated with stent placement was PV thrombosis, which resulted in stent failure, but we observed no portal hypertension. In the other 4 patients, the stent has remained functioning, and there was no clinical evidence of portal hypertension. PV stents are effective for intractable PV stenosis in children. PV stents were successfully placed in children as young as 3 years old and weighing 13 kg. Our data suggests that a stent placed in young children does not cause portal hypertension as patients grow.

Twelve-month clinical outcomes of "nano-crush technique" for the treatment of bifurcation lesions using ultra-thin (60 µm) sirolimus-eluting coronary stents.

Provisional stenting is preferred for bifurcation lesion; however, certain anatomical substrate does require two stents as a part of dedicated stent technique. Here, the present study evaluated outcomes of ultra-thin (60 µm) Supra family sirolimus-eluting stent (SES) (Sahajanand Medical Technologies Limited, Surat, India) for dedicated bifurcation lesions using nano-crush technique at 12 months angiographic follow-up. This was prospective, single-center observational study which enrolled patients with de novo bifurcation lesion and underwent angioplasty with Supra family SES using nano-crush technique at a tertiary care center in India, between March-2017 and February-2019. Primary endpoint at 12 months was target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction (TV-MI), and clinically driven target lesion revascularization (CD-TLR). Secondary endpoints included patient-oriented composite endpoint (POCE), all-cause death, any revascularization, clinically driven target vessel revascularization, stent thrombosis, periprocedural and spontaneous MI, and device failure. The study enrolled total 63 patients with a mean age of 62.5±4.9 years and had male dominance (89%). Left main (LM) bifurcation and non-LM bifurcation were observed in 21 (33%) and 42 (67%) patients, respectively. Total 50 (80%) patients had Medina class- 1,1,1. At 12 months, TLF occurred in 4 (6%) patients which included one cardiac death (1.5%), two (3.0%) TV-MI, and one CD-TLR (1.5%). POCE was observed in 6 (9.6%) patients. Stent failure was seen in 2 (3.1%) patient and one patient (1.5%) developed late stent thrombosis. Twelve months angiographic follow-up indicated intact stent patency in all other patients. On multivariate analysis, LM bifurcation, renal dysfunction, LM bifurcation with renal dysfunction, ejection fraction (<35%) and calcified lesion were found as predictors of TLF. Dedicated stenting with ultra-thin Supra family SES for complex bifurcation lesion using nano-crush technique reported acceptable clinical outcomes among real-world patients and can be performed safely with ease without any procedural complications.

Balloon expandable coronary stent materials: a systematic review focused on clinical success

Balloon expandable coronary stenting has revolutionized the field of interventional cardiology as a potential, minimally invasive modality for treating coronary artery disease. Even though stenting is successful compared to angioplasty (that leaves no stent in place), still there are many associated clinical complications. Bare metal stents are associated with in-stent restenosis caused mostly by neointimal hyperplasia, whereas success of drug-eluting stents comes at the expense of late-stent thrombosis and neoatherosclerosis. Even though innovative and promising, clinical trials with bioabsorbable stents reported thrombosis and a rapid pace of degradation without performing scaffolding action in several instances. It should be noted that a vast majority of these stents are based on a metallic platform which still holds the potential to mitigate major cardiovascular events and reduced economic burden to patients, alongside continuous improvement in stent technology and antiplatelet regimes. Hence, a systematic review was conducted following PRISMA guidelines to assess the clinically relevant material properties for a metallic stent material. From a materials perspective, the major causes identified for clinical failure of stents are inferior mechanical properties and blood-material interaction–related complications at the stent surface. In addition to these, the stent material should possess increased radiopacity for improved visibility and lower magnetic susceptibility values for artefact reduction. Moreover, the review provides an overview of future scope of percutaneous coronary interventional strategy. Most importantly, this review highlights the need for an interdisciplinary approach by clinicians, biomaterial scientists, and interventional cardiologists to collaborate in mitigating the impediments associated with cardiovascular stents for alleviating sufferings of millions of people worldwide.

Management strategies and outcome of ureterovaginal fistulae: A systematic review and meta-analysis.

Genitourinary fistula is a distressful condition involving mental, social, marital, and financial repercussions. The objective of this study is to systematically evaluate etiology, clinical presentation, diagnosis, the timing of repair, and perform a meta-analysis evaluating the success rate of various treatment modalities with respect to time taken to seek treatment. We performed a critical review of PubMed/Medline, Embase, and the Cochrane Library in April 2020 according to the PRISMA statement. Seventeen studies were included in the final analysis and all were retrospective in design. Each article was rated by the evidence-based medicine levels of evidence scale and the Methodological Index for Nonrandomized Studies scale for assessment of bias amongnonrandomized studies. Of the 799 fistulae reported in 17 studies, endoscopic management was done in 35.6% (12 studies), whereas surgical management was preferred in 85.6% fistulae (15 studies). The pooled success of endoscopic stenting was 32% (95% confidence interval [CI]: 7-64) and 100% (95% CI: 98-100) in operated patients. Patients who underwent stenting within 2 weeks (20%), 2-6 weeks (21%), and >6 weeks (40%) had pooled success rates of 95% (95% CI: 87-100), 46% (95% CI: 0-100), and 20% (95% CI: 1-49), respectively. Patients who underwent surgical management <6 weeks (15.9%) and >6 weeks (22%) of diagnosis had pooled success rates of 100% (95% CI: 99-100) and 100% (95% CI: 99-100), respectively. Stent placement as early as <6 weeks (preferably < 2 weeks) had better outcomes as compared to >6 weeks. Proceeding to surgery regardless of timing in cases of stent failure seems to be a feasible option.

Factors Associated with Ureteral Stent Failure in Patients with Malignant Ureteral Obstruction.

Introduction: Management of malignant ureteral obstruction (MUO) with ureteral stents remains a clinical challenge, often involving frequent stent exchanges attributable to stent failure or other urological complications. We report our institutional experience with ureteral stents for management of MUO, including analysis of clinical factors associated with stent failure. Methods: We performed a retrospective review of patients treated with indwelling ureteral stents for MUO in nonurothelial malignancies at our tertiary-care institution between 2008 and 2019. Univariate Cox proportional hazards analysis was performed to identify clinical variables associated with stent failure and stent-related complications. Stent failure was defined as need for unplanned stent exchange, placement of percutaneous nephrostomy (PCN), or tandem stents. Results: In our cohort of 78 patients, the median (range) number of stent exchanges was 2 (0-17) during a total stent dwell time of 4.3 (0.1-40.3) months. Thirty-four patients (43.6%) developed a culture-proven urinary tract infection (UTI) during stent dwell time. Thirty-five patients (44.8%) had stent failure. Twenty-two patients (28.2%) underwent unplanned stent exchanges, 23 (29.5%) required PCN after initial stent placement, and 6 (7.7%) required tandem stents. Ten (28.6%) patients with stent failure were treated with upsized stents, which led to resolution in seven patients. Stent failure occurred with 20/44 (45.4%) Percuflex™, 15/27 (55.6%) polyurethane, and 2/3 (66.7%) metal stents. In patients with ≥2 exchanges (N = 45), median time between exchanges was 4.1 (2.0-14.8) months. Bilateral stenting and history of radiation predicted UTI development. Median overall patient survival after initial stent placement was 19.9 months (95% CI 16.5-37.9 months). Conclusions: Ureteral stent failure poses a significant medical burden to patients with MUO. Better methods to minimize stent-related issues and improve patient quality of life are needed. Using a shared decision-making approach, clinicians and patients should consider PCN or tandem stents early in the management of MUO.

Promising PTFE-coating technology of Optimus-CVS™ stents: The new player for congenital heart disease interventions

BackgroundThe use of covered stents (CVS) in congenital heart disease (CHD) interventions is increasing but intrinsic properties of commercially available material remain not optimal. The Optimus-CVS™ (AndraTec GmbH, Koblenz, Germany) is a new balloon-expandable, non-premounted, Cobalt–Chromium stent with patented hybrid-cell design, innovative end-free Nano-PTFE sandwich-covering, and competitive deliverability features. Methods and resultsThree patients with CHD received Optimus-CVS during December 2020 at our institution. Indications for CVS implantation were relief of complex aortic recoarctation (57 ​mm long Optimus-CVS-XL), treatment of intra-stent intimal proliferation in Fontan circulation (48 ​mm long Optimus-CVS-XXL), and as a bail-out for conduit rupture during pulmonary valve implantation (33 ​mm long Optimus-CVS-XXL). Procedures were successful and straightforward. Target diameter was achieved and stent shortening was minimal and as expected. No stent failure was recorded on short-term follow-up. ConclusionsOptimus-CVS appears to be a reliable high-performing CVS alternative in major CHD situations where CVS are needed. Optimus-CVS offers interesting construction characteristics, smart covering design, and the largest portfolio in terms of diameters and length optimizing lesion care and improving outcomes.

Prevalence, Morphology, and Predictors of Intra-Stent Plaque Rupture in Patients with Acute Coronary Syndrome: An Optical Coherence Tomography Study.

Previous studies have shown that plaque rupture (PR) is the most important cause of acute coronary syndrome (ACS). However, the potential impact of intra-stent PR on stent failure manifesting as ACS and the optical coherence tomography (OCT) features of these lesions was still less clear. Therefore, we aimed to investigate the characteristics of OCT-defined in-stent PR and identify the potential risk factors for PR in ACS patients. All 213 ACS patients were stratified into two groups according to the occurrence of in-stent PR. The baseline characteristics of all patients were investigated. A multivariable logistic regression was performed to identify factors associated with the formation of PR. OCT findings showed that 80 patients had in-stent PR, and 133 patients were without PR. Patients who suffered in-stent PR had higher blood lipid levels (P < .050) and longer duration of stent failure (P = .001). Moreover, thrombolysis in myocardial infarction (TIMI) 0/1 flow was more prone to the formation of PR (P = .010), and lesions in the PR group harbored more macrophages and cholesterol crystals (P < .001 and P = .024). On multivariate analysis, presentation of myocardial infarction (MI) and OCT findings of lipidic neointima length showed a 3.6-fold (P = .004) and 1.3-fold (P < .001) higher risk for occurrence of in-stent PR. ACS patients who suffered in-stent PR had a longer duration of stent failure and more ISR occurring in non-culprit vessels. Given the distinguishing features between ACS patients with in-stent PR and non-PR, potential targeted therapy was warranted to improve the prognosis of patients with in-stent PR.

Adverse events associated with AXIOS stents: Insights from the manufacturer and user facility device experience database.

ABSTRACTBackground and Objectives:The AXIOS stent is indicated for transgastric or transduodenal drainage of symptomatic pancreatic pseudocysts and symptomatic walled off necrosis. The AXIOS stent functions as a conduit which allows solid and liquid pancreatic fluid collections (PFC) contents to pass into the luminal GI tract and also allows the passage of standard and therapeutic endoscopes into the PFC to perform endoscopic debridement. We aim to investigate the number and type of complications associated with AXIOS stents.Materials and Methods:We analyzed postmarketing surveillance data from the Food and Drug Administration Manufacturer and User Facility Device Experience (MAUDE) database January 2016 to February 2021.Results:During the study period, approximately 588 reports with 579 device issues and 250 patient complications were identified. Most device complications were due to stent positioning problems or stent malpositioning (n = 206; 35.6%), followed by stent migration (n = 72; 12.4%), premature deployment (n = 61; 10.5%), material integrity (n = 56; 9.6%), deployment failure (n = 47; 8.1%), and difficulty removing the stent (n = 45; 7.7%). The most reported patient adverse events were hemorrhage/bleeding (n = 81; 32.4%), perforation (n = 26; 10.4%), pain (n = 22; 8.8%), unspecified infection (n = 20; 8.0%), and death (n = 17; 6.8%).Conclusions:Findings from the MAUDE database highlight patient and device complications which endoscopists should be aware of before AXIOS stent placement.

A viewpoint on material and design considerations for oesophageal stents with extended lifetime

Oesophageal stents are meshed tubular implants designed to maintain patency of the oesophageal lumen and attenuate the symptoms of oesophageal cancer. Oesophageal cancers account for one in twenty cancer diagnoses and can lead to dysphasia, malnutrition and the diminishment of patient quality of life (QOL). Self-expanding oesophageal stents are the most common approach to attenuate these symptoms. Recent advances in oncological therapy have enabled patient survival beyond the lifetime of current devices. This introduces new complications for palliation, driving the need for innovation in stent design. This review identifies the factors responsible for stent failure. It explores the challenges of enhancing the longevity of stent therapies and outlines solutions to improving clinical outcomes. Discussions focus on the role of stent materials, construction methods, and coatings upon device performance. We found three key stent enhancement strategies currently used; material surface treatments, anti-migratory modifications, and biodegradable skeletons. Furthermore, radioactive and drug eluting stent designs were identified as emerging novel treatments. In conclusion, the review offers an overview of remaining key challenges in oesophageal stent design and potential solutions. It is clear that further research is needed to improve the clinical outcome of stents and patient QOL.

Intracoronary optical coherence tomography—An introduction

AbstractOptical coherence tomography (OCT) utilizes near infrared light with a wavelength of 1.30 μm and is generated from a rotating fibre‐optic system. When compared to intravascular ultrasound (IVUS), the shorter wavelength of OCT (1.3 μm) confers excellent axial resolution but at the cost of lower depth penetration (1–2 mm vs. 5–6 mm). Red blood cells have a strong tendency to absorb and scatter light, which attenuates the image. Therefore, when assessing coronary arteries with OCT, it is important to clear blood from the field of examination and this is usually done with a contrast agent. This makes it prone to artefacts from residual blood, and limits its use in patients with advanced chronic kidney disease, ectatic vasculature and aorto‐ostial lesions where IVUS tends to be preferred. However, OCT outperforms IVUS in the assessment of calcific lesions, identification of high‐risk plaque features, and studying the mechanism of stent failure. In this article, we provide an up‐todate review of the technology behind OCT, its limitations, and how the two intracoronary imaging modalities compare in various clinical scenarios.

Tumor Stent for Chronic Ureteral Obstruction: Which Are Predictors of Stent Failure?

Purpose: To identify predictors of UROSOFT® tumor stent failure. According to the manufacturer, this reinforced ureteral stent has a maximal dwell time of 6 months. Nonetheless, stent failure may reduce this maximal dwell time. Methods: All patients undergoing first-time UROSOFT tumor stent insertion in our institution between 2010 and 2018 were considered for this retrospective analysis. Primary endpoint was stent failure and defined as premature stent exchange or percutaneous nephrostomy insertion. The local ethics committee approved the study protocol (study ID: BASEC 2020-00175). Results: In total, 182 patients were available for analysis. Median age was 68 years. Causes for tumor stent placement were extrinsic ureteral obstruction in 144 patients (79%) and intrinsic obstruction in 38 patients (21%). Tumor stent failure-free survival estimates at 1, 2, 3, 4, and 5 months were 89%, 83%, 76%, 65%, and 52%, respectively. Patients with stent failure had significantly higher grade of hydronephrosis, higher urinary culture bacterial growth, higher serum white blood cell count, higher C-reactive protein, and lower estimated glomerular filtration rate at the time of reintervention, compared with patients who underwent regular stent exchange. Of all baseline and perioperative parameters, we found bilateral insertion, intrinsic ureteral obstruction, and urinary tract infection (UTI) at time of tumor stent insertion to be significant and independent predictors of stent failure (all p < 0.05). Conclusion: Despite a theoretical maximal dwell time of 6 months, ∼50% of all cases are subject to premature stent failure. Predictors of stent failure are bilateral insertion, intrinsic ureteral obstruction, and UTI at the time of tumor stent insertion. Preoperative antibiotic therapy may impact on stent failure rate.

Optical coherence tomography and coronary artery ectasia: the critical role of intracoronary imaging for optimal results of percutaneous coronary intervention

Percutaneous coronary intervention (PCI) in coronary artery ectasia is technically challenging, particularly regarding appropriate stent sizing, and it is associated with a higher incidence of adverse events. In this case report, a 63-year-old male patient, heart transplant recipient, underwent elective follow-up coronary angiography in the absence of clinical symptoms. Five years previously the patient was treated with coronary angioplasty and drug-eluting stent implantation for critical lesions of the left anterior descending coronary artery. Angiographic images showed a focal in-stent haziness at the level of an ectatic segment. To elucidate this finding, optical coherence tomography (OCT) was performed. Intracoronary imaging showed severe malapposition of the proximal end of the stent, with an intraluminal signal-rich structure, suggestive of organized stent thrombosis. Stent dilation was performed to maximal recommended diameter, with significant reduction of the malapposed area, as shown by repeated OCT pullbacks. Intracoronary imaging is particularly valuable in PCI of ectatic vessels to guide appropriate stent sizing and avoid stent malapposition. OCT, thanks to its superior spatial resolution in comparison with other intravascular imaging techniques, provides advantages for stent optimization and evaluation of stent failure causes. However, its limited imaging area and possible incomplete blood clearance may limit its usefulness in severely ectatic vessels.

Design and Rationale for a Real-World Prospective, Multicenter Registry of Myocardial Revascularization Failure and Secondary Revascularization: The REVASEC Study

AimTo investigate key aspects of the problem of myocardial revascularization failure (MRF) and repeat or secondary myocardial revascularization (SR) in contemporary practice. MethodsThe registry of secondary revascularization (REVASEC) is an investigator-initiated, multicenter, prospective registry enhanced with data monitoring and independent event adjudication (ClinicalTrials.govNCT03349385). It includes patients with prior revascularization referred to coronary angiography for suspected MRF with broad inclusion criteria. The main objectives are to describe the characteristics of patients with prior revascularization referred for repeat angiography, to describe and the rate and mechanisms of MRF (stent or graft failure, coronary artery disease progression or residual coronary artery disease); to evaluate the management including medical treatment and SR of these patients; and to assess the prognosis according to the outlined causative mechanisms. The registry has one year follow up for the primary endpoint (Patient-oriented composite endpoint including all-cause death, any myocardial infarction or any new unplanned revascularization according to subsets of MRF), but extended follow-up will be carried out up to 5 years. ConclusionThe REVASEC Registry will provide updated data on the characteristics, patterns of treatment, and 1-year outcomes of patients with MRF and SR in contemporary clinical practice.