Neointimal Coverage Research Articles

3-month analysis of neointimal coverage with different profiles stents in stable ischemic heart disease

3-month analysis of neointimal coverage with different profiles stents in stable ischemic heart disease

Optimal Dual Antiplatelet Therapy Duration For Carotid Artery Stenting On the Basis of Angioscopic Findings

Background Dual antiplatelet therapy plays a crucial role in preventing thrombosis in the perioperative period of carotid artery stenting (CAS); however, it has been associated with a risk of hemorrhagic complications. A standard regimen for the duration and combination of antiplatelet therapy is yet to be established. Angioscopy enables direct visualization of neointimal coverage and might help determine the optimal duration of dual antiplatelet therapy through the assessment of post‐CAS neointimal coverage. Methods This prospective study enrolled 20 patients who were scheduled to undergo CAS at the Osaka Police Hospital. A 2‐month post‐CAS period was chosen for angioscopic neointima evaluation on the basis of previous evidence of reliable neointimal coverage 2 months following coronary artety stenting. Furthermore, antiplatelet therapy was initiated 1 week before CAS and continued until angioscopic examination. Angioscopic evaluation categorized the degree of neointimal coverage and was supplemented with carotid ultrasonography and biplane angiography. Results Coincidentally, a dual‐layer stent was used in all cases. The stent lumen was observed in 19 of the 20 cases. One case was difficult to evaluate owing to poor visibility. Angioscopy showed complete neointimal coverage in 18 of 19 cases and partial coverage in 1 case. Ultrasonography could detect neointima in 9 of 20 cases, and angiography showed a radiolucent gap suggestive of neointima in all cases in which neointima was confirmed via angioscopy. No post‐CAS or procedural complications occurred. Conclusion Angioscopy performed 2 months following CAS revealed large neointimal coverage, suggesting that a 2‐month duration of dual antiplatelet therapy is generally sufficient. However, as a limitation, this study was performed using the same dual‐layer stent; thus, additional studies with other stents are required.

A novel intrasaccular aneurysm device with high complete occlusion rate: initial results in a rabbit model

BackgroundIntrasaccular flow-disrupting devices are a safe and effective treatment strategy for intracranial aneurysms. We utilized high-frequency optical coherence tomography (HF-OCT) and digital subtraction angiography (DSA) to evaluate SEAL Arc, a...

Assessment of Effectiveness of the Algorithm for Automated Quantitative Analysis of Metallic Strut Tissue Short-Term Coverage with Intravascular Optical Coherence Tomography.

Background: Due to its high resolution, optical coherence tomography (OCT) is the most suitable modality for neointimal coverage assessments. Evaluation of stent healing seems crucial to accurately define their safety profile since delayed healing is connected with stent thrombosis. This study aimed to present an algorithm for automated quantitative analysis of stent strut coverage at the early stages of vessel healing in intravascular OCT. Methods: A set of 592 OCT frames from 24 patients one month following drug-eluting stent implantation was used to assess the algorithm's effectiveness. Struts not covered on any side or covered but only on one side were categorized as uncovered. The algorithm consists of several key steps: preprocessing, vessel lumen segmentation, automatic strut detection, and measurement of neointimal thickness. Results: The proposed algorithm proved its efficiency in lumen and stent area estimation versus manual reference. It showed a high positive predictive value (PPV) (89.7%) and true positive rate (TPR) (91.4%) in detecting struts. A qualitative assessment for covered and uncovered struts was characterized by high TPR (99.1% and 80%, respectively, for uncovered and covered struts) and PPV (77.3% and 87%). Conclusions: The proposed algorithm demonstrated good agreement with manual measurements. Automating the stent coverage assessment might facilitate imaging analysis, which might be beneficial in experimental and clinical settings.

Impact of baseline yellow plaque assessed by coronary angioscopy on vascular response after stent implantation

BackgroundThe relationship between baseline yellow plaque (YP) and vascular response after stent implantation has not been fully investigated. MethodsThis was a sub-analysis of the Collaboration-1 study (multicenter, retrospective, observational study). A total of 88 lesions from 80 patients with chronic coronary syndrome who underwent percutaneous coronary intervention were analyzed. Optical coherence tomography (OCT) and coronary angioscopy (CAS) were serially performed immediately and 11 months after stent implantation. YP was defined as the stented segment with yellow or intensive yellow color assessed by CAS. Neoatherosclerosis was defined as a lipid or calcified neointima assessed by OCT. OCT and CAS findings at 11 months were compared between lesions with baseline YP (YP group) and lesions without baseline YP (Non-YP group). ResultsBaseline YP was detected in 37 lesions (42 %). OCT findings at 11 months showed that the incidence of neoatherosclerosis was significantly higher in the YP group (11 % versus 0 %, p = 0.028) and mean neointimal thickness tended to be lower (104 ± 43 μm versus 120 ± 48 μm, p = 0.098). CAS findings at 11 months demonstrated that the dominant and minimum neointimal coverage grades were significantly lower (p = 0.049 and P = 0.026) and maximum yellow color grade was significantly higher (p < 0.001) in the YP group. ConclusionsBaseline YP affected the incidence of neoatherosclerosis as well as poor neointimal coverage at 11 months after stent implantation.

Importance of Short-Term Neointimal Coverage of Drug-Eluting Stents in the Duration of Dual Antiplatelet Therapy.

Dual antiplatelet therapy (DAPT) is mandatory after percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation, but optimal DAPT duration remains a topic of intense discussion. The shorter regimen of DAPT might be especially beneficial for high-bleeding-risk (HBR) patients. Novel stent platforms have been designed with innovations that should facilitate vessel healing following stent implantation and enable short DAPT. This review aimed to summarize evidence of the neointimal coverage of short-term stents and their implications for DAPT duration. Results from histological and optical coherence tomography (OCT) studies confirm the significant role of uncovered struts after the implantation of a stent in patients presenting with late stent thrombosis. Several studies have shown favorable vessel healing at one month (with 83.2% of covered struts, on average) and three months following stent implantation (with 93.3% of covered struts, on average). Solely HBR patient trials have proven that one month of DAPT can be applicable and safe in this population. Three-month DAPT was tested in a more diverse population and remains effective and safe in comparison to a longer DAPT regimen. That evidence proves that short-term DAPT might be applicable, especially for HBR patients.

Evaluation of the EMBOPIPE flow diverter device: in vivo and in vitro experiments

BackgroundAlthough flow diverter device (FDD) has brought revolutionized advances in endovascular treatment of intracranial aneurysms, it also presents considerable drawbacks as well, as the innovation for novel device has never stopped. This preclinical research aims to evaluate the safety and efficacy of a newly developed FDD, the EMBOPIPE, through in vivo and in vitro experiments.MethodsAneurysms were induced in 20 New Zealand white rabbits which were randomized to three follow-up groups according to the time elapsed after EMBOPIPE implantation (28, 90, and 180 days). Additional EMBOPIPEs were implanted in the abdominal aorta to cover the renal artery in nine rabbits. Angiography was performed immediately after device placement in all groups. Aneurysm occlusion, patency of renal arteries, and pathological outcomes were assessed. For the in vitro experiments, we measured the thrombogenic potential of EMBOPIPEs (n = 5) compared with bare stents (n = 5) using the Chandler loop model. Evaluation indicators were the platelet counts, macroscopic observations and scanning electron microscopy.ResultsEMBOPIPEs were successfully deployed in 19 of 20 rabbit aneurysms (95.0%). The rates of complete or near-complete aneurysm occlusion were 73.3%, 83.3%, and 100% in the 28-, 90-, and 180-day groups, respectively. All renal arteries covered by EMBOPIPEs remained patent, and the mean difference in renal artery diameter before and after the device placement in the three groups was 0.07 mm, 0.10 mm, and 0.10 mm, respectively (p = 0.77). Renal pathology was normal in all cases. The pathological findings of the aneurysms were as follows: thickened and adequate neointimal coverage at the aneurysm neck, minimal inflammatory response, near-complete smooth muscle cell layer, and endothelialization along the device. In vitro experiments showed that the platelet counts were significantly higher in EMBOPIPE blood samples than in bare stent samples and that platelet adhesion to the device was lower in the EMBOPIPE stent struts compared with bare stent struts through macroscopic observations and scanning electron microscopy.ConclusionsThe EMBOPIPE can achieve high rates of aneurysm occlusion while maintaining excellent branch artery patency. It exhibited wonderful pathological results. This novel device with phosphorylcholine surface modification could reduce platelet thrombus attached to the stent struts.

Long-term bio-functional performance of a novel, self-positioning balloon expandable transcatheter biological aortic valve system in the ovine aortic banding model.

The aim of the study was to evaluate bio-functionality of a novel, proprietary balloon-expandable biological transcatheter aortic valve implantation (TAVI) system (InFlow, CardValve Consortium, Poland) in an ovine model of aortic banding. Surgical ascending aorta banding was created in 21 sheep. Two weeks later, 18 biological valves were implanted within the model using 15-16 F InFlow TAVI systems and carotid cut-down approach. Follow-up transthoracic echocardiography was performed at 30, 90, and 180-day. At designated time, animals were euthanized and valves harvested for analysis. All sheep survived the banding procedure. There were 4 (22%) procedure related deaths within a 7-day period. During the observation an additional 2 sheep died. In one, the valve dislocated after the procedure - the animal was excluded. Two animals completed 30-day follow up, five 90-day follow-up and four terminal follow-up of 180 days. Valves examined via transesophageal echocardiography showed proper hemodynamic parameters without evidence of structural valve deterioration. The maximum and average flow gradients at 180 days were 31.4 (23.3-37.7) and 17.5 (13.1-20.2) mmHg, respectively. There was one case of moderate insufficiency and no case of perivalvular leaks. By histopathology, there were no inflammation, thrombosis, nor calcifications in any tested valves at long-term follow-up. Neointimal coverage of stent struts increased with time from basal part in "early" groups to nearly 3/4 of stent length in the 180-day group. The pannus tissue showed maturation that increased with time with no stenotic "collar" visible in orthotopically implanted valves. The study showed good hemodynamic performance, durability and biocompatibility of the novel biological THV.

Comparison of the “Late Catch-Up” Phenomenon Between BuMA Supreme and XIENCE Stents Through Serial Optical Coherence Tomography at 1–2 Month and 2 Year Follow-Ups: A Multicenter Study

Objectives: This study was aimed at comparing the “late catch-up” phenomenon between the BuMA Supreme bioresorbable polymer sirolimus-eluting stent and the XIENCE stent through serial optical coherence tomography (OCT) at within 2 months and 2 year follow-ups. Methods: A total of 49 of 75 patients from the PIONEER-II study were enrolled in a 2 year OCT follow-up study; 44 patients with 50 lesions were included in the statistical analysis. The primary endpoints were neointimal thickness and late luminal loss (LLL) after stent implantation. Results: The stenosis diameter, and minimum in-stent or in-segment diameter, did not significantly differ between the BuMA Supreme and XIENCE arms at within 2 months and 2 year follow-ups. The strut neointimal coverage and thickness were greater in the BuMA group than the XIENCE group at the 1 and 2 month follow-ups (P = 0.044 and P = 0.010, respectively) but not at the 2 year OCT follow-up. Neither early luminal loss at the within 2 months follow-up (P = 0.849) nor LLL at the 2 year OCT follow-up (P = 0.613) showed differences between device arms. No significant differences in imaging and clinical endpoints were observed between device arms at follow-up. Conclusions: The BuMA Supreme stent’s faster re-endothelization with no “late catch-up” phenomenon has potential advantages over the XIECE stent for patients with coronary artery disease and high bleeding risk because it decreases the duration of dual antiplatelet therapy.

Effects on re-endothelialisation with Bydureon treatment add on to insulin versus insulin alone, both in combination with metformin in type 2 diabetic subjects: Rebuild study

Abstract Background Patients with type 2 diabetes (T2D) have a higher risk of in-stent restenosis and stent thrombosis following a percutaneous coronary intervention1. The key mechanism for preventing these events after stenting is a restored and well-functioning neo-endothelium2. Several large, randomized trials have shown cardioprotective effect of Glucagon Like Pepetide-1 receptor (GLP-1R) agonists therapy lowering the risk of major adverse cardiovascular events. In addition, activation of GLP-1R has been suggested to induce several effects on the vasculature3 that may reduce not only the risk of atherosclerosis progression, but even the risk of stent failure following an angioplasty. Purpose To evaluate the potential beneficial effect of the GLP-1R agonist Bydureon in the endothelialisation of modern drug-eluting stents (DES) in patients with T2D. Methods 38 subjects with T2D and coronary artery disease who were eligible for revascularisation with implantation of DES were included and randomized to either treatment with Bydureon (once weekly) over the standard treatment, or to standard treatment alone. After 12 weeks, a new coronary angiography was performed to evaluate the coverage of the DES and the presence of neo-atherosclerosis by optical coherence tomography. The main outcome was the percentage of stent coverage at 12 weeks. Descriptive data is shown as median (percentile 25th- 75th). Results The two groups were well balanced regarding baseline clinical characteristics (Table). Neo-intimal coverage could be assessed in all 33 subjects that completed follow-up. DES coverage was 95% (88.7-98.5%) in the Bydureon group and 91.4% (88.8-98.5%) in the Control group (p=0.692). There were no significant differences between groups neither in the thickness of neo-intima (0.2 mm in both groups, p=0.471), nor the maximal in-stent obstruction by neo-intima (15.5% in Bydureon group vs 14.7% in Control group, p= 0.801). Weight decrease was greater in Bydureon group compared to Control group (-7.8 kg vs +0.14 kg, p=0.014), and so was also HbA1c reduction (-11.4 mmol/mol vs -4.7 mmol/mol, p=0.001). No significant differences were detected on the rate of target lesion revascularisation between groups (p=0.224). Conclusion Twelve weeks treatment with Bydureon did not lead to a significantly better stent coverage in patients with T2D. No significant differences in the occurrence of neo-atherosclerosis were detected between groups.Table:Baseline clinical characteristicsImage:Diagram of Methods and Results

Vascular healing of Combo plus stents in patients with acute coronary syndrome

Abstract Background The Combo stent has an abluminal sirolimus-eluting coating composed of a biodegradable polymer to form a drug-eluting stent platform. Sirolimus release is completed in 30 days, and the biodegradable polymer disappears within 90 days. This dual therapy approach aims for neointimal suppression while retaining the endothelial progenitor cell–capturing prohealing benefits enabling rapid endothelialization. However, in patients with acute coronary syndrome (ACS), early vascular healing after COMBO stent implantation remains unknown. Purpose The aim of this study is to elucidate the early phase vascular responses in patients with ACS after COMBO stent implantation at 1 month and 6 months follow-up by using optical coherence tomography (OCT). Methods Twenty-eight patients who underwent primary percutaneous coronary intervention (PCI) for AMI with COMBO stent between March 2020 and July 2020 were examined. All patients received follow-up OCT at 1 and 6 months after primary PCI. For assessment of each strut, OCT images were analyzed at 1.0-mm intervals throughout the stented segment. The degree of strut coverage by OCT were measured both 1 month and 6 months. Results The neointimal thickness were 0.110 ± 0.036 mm at 1 months and 0.217 ±0.083 mm at 6 months (P&amp;lt; 0.001). The median rate of any covered struts was 40.2% at 1 month and 89.5% at 6 months (P&amp;lt; 0.001). The median rate of definite uncovered struts was 14.4% at 1 month and 0.7% at 6 months (P&amp;lt; 0.001). Major adverse cardiac events (MACE) were limited to two target vessel failure without target lesion revascularization. No definite or probable stent thrombosis was noted. Conclusions In patients with MI, the COMBO stent is associated with a high degree of neointimal strut coverage at 1 monthfs. Furthermore, almost complete vascular healing at 6 months is observed. These findings may have impact on the duration of dual anti-platelet therapy in patients with MI who underwent PCI using COMBO stent.

Abstract 17285: Impact of Baseline Yellow Plaque Assessed by Coronary Angioscopy on 11-month Vascular Response After Stent Implantation

Background: In-stent yellow plaque (YP) evaluated by coronary angioscopy (CAS) 1 year after stent implantation is associated with the future adverse cardiac event. However, the impact of baseline YP on vascular response has not been fully investigated. Methods: This was a sub-analysis of the Collaboraiton-1 study (multicenter, retrospective, observational study). A total of 88 lesions from 80 patients with chronic coronary syndrome who underwent percutaneous coronary intervention with polymer-free biolimus A9-coated stent or durable-polymer everolimus-eluting stent implantation were analyzed. Optical coherence tomography (OCT) and CAS were serially performed immediately and 11 months after stent implantation. YP was defined as the stented segment with yellow or intensive yellow color assessed by CAS. Neoatherosclerosis was defined as a lipid or calcified neointima assessed by OCT. Neointimal coverage (NIC) over the stent was classified into 4 grades by CAS: grade 0, stent struts fully visible; grade 1, stent struts bulging into the lumen, although covered; grade 2, stent struts embedded in the neointima, but translucently visible; and grade 3, stent struts fully embedded and invisible. OCT and CAS findings at 11 months were compared between the lesions with baseline YP (YP group) and those without YP (Non-YP group). Results: Baseline YP was detected in 37 lesions (42%). OCT findings at 11 months showed that the incidence of neoatherosclerosis was significantly higher in YP than Non-YP groups (11% versus 0%, P=0.028) and mean neointimal thickness tended to be lower (104±43 μm versus 120±48 μm, P=0.098). CAS finding at 11 months demonstrated that dominant and minimum NIC grades were significantly lower (Figure) and maximum yellow color grade was significantly higher in YP than Non-YP groups. Conclusions: Baseline YP affected the incidence of neoatherosclerosis as well as poor neointimal coverage at 11 months after stent implantation.

Tissue responses to everolimus-eluting stents implanted in severely calcified lesions following atherectomy

Histopathological examination has revealed that stents on severely calcified plaques were associated with delayed vascular healing. Although atherectomy devices can increase the number of malapposed struts, tissue responses to implanted drug eluting stents in atherectomy patients remain largely unknown. This retrospective observational study included 30 patients who underwent atherectomy and everolimus-eluting stent (EES) deployment for severely calcified coronary lesions (biodegradable polymer EES (BP-EES), n = 15; durable polymer EES (DP-EES), n = 15). Optical coherence tomography was carried out at baseline and follow-up, and struts with acute stent malapposition (ASM) were categorized as struts on modified calcium (mod-Ca), non-modified calcium (non-mod-Ca), or non-calcium (non-Ca). Adequate vascular healing, defined as ASM resolution with neointimal coverage, was compared between the BP-EES and DP-EES groups. Multivariate linear regression analysis using a generalized estimated equation revealed that BP-EES use was associated with significantly better adequate vascular healing compared with DP-EES (odds ratio [OR]: 3.691, 95% confidence interval [CI] 1.175–11.592, P = 0.025). adequate vascular healing was associated with the underlying plaque morphology (mod-Ca vs non-mod-Ca: OR 2.833, 95% CI 1.491–5.384, P = 0.001; non-Ca vs non-mod-Ca: OR 1.248, 95% CI 0.440–3.543, P = 0.677). This study demonstrates that drug-eluting stent selection and calcium modification are possible factors affecting vascular healing of malapposed struts in severely calcified lesions.Graphical

Large, Wide-Neck, Side-Wall Aneurysm Treatment in Canines Using NeuroCURE: A Novel Liquid Embolic.

Untreated intracranial aneurysms can rupture and result in high rates of morbidity and mortality. Although there are numerous approved endovascular aneurysm treatment devices, most require dual anti-platelet therapy, are minimally biocompatible, or are prone to recanalization. Neurovascular Controlled Uniform Rapid Embolic (NeuroCURE) is an innovative polymer gel material with long-term stability, biocompatibility, and hemocompatibility developed for the treatment of large, wide-neck aneurysms. Sidewall aneurysms were surgically created in 10 canines and NeuroCURE was injected through a 0.025 microcatheter under a single balloon inflation period. Aneurysm treatment was angiographically assessed post-embolization and pre-term with Raymond-Roy occlusion classification and a qualitative flow grade scale. Aneurysm neck stability and biocompatibility was histologically assessed to grade platelet/fibrin thrombus, percent endothelialization, and neointimal formation. Aneurysm sac stability was assessed by NeuroCURE sac content, inflammation, and neo-angiogenesis scales. Explanted aneurysms exhibited a smooth surface at the aneurysm neck with nearly complete neointimal coverage at 3-months. By 6-months, neck endothelialization was 100% in all animals (average Raymond-Roy occlusion classification of 1.2), with no instances of aneurysm recanalization or parent vessel flow compromise. Biocompatibility assessments verified a lack of inflammatory response, neo-angiogenesis, and platelet/fibrin thrombus formation. The NeuroCURE material promotes progressive occlusion of wide-necked side wall aneurysms over time without the need for dual antiplatelet agents. NeuroCURE also promotes neointimal tissue infill without dependence on thrombus formation and thus resists aneurysm recanalization. NeuroCURE remains a compelling investigational device for the treatment of intracranial aneurysms.

Angioscopic Evaluation of Vascular Response After Fluoropolymer-Based Drug-Eluting Stent Implantation for Femoropopliteal Artery Lesions.

Although favorable clinical outcomes have been demonstrated for fluoropolymer-based paclitaxel-eluting stents (FP-DES) in the treatment of femoropopliteal lesions, the vascular response after implantation has not been systematically studied through intravascular imaging.Methods and Results: We angioscopically compared FP-DES: 24 in the early phase (mean [±SD] 3±1 months), 26 in the middle phase (12±3 months), and 20 in the late phase (≥18 months) after implantation. The dominant neointimal coverage grade, heterogeneity of neointimal coverage grade, and thrombus adhesion in the stent segment were evaluated. Neointimal coverage was graded as follows: Grade 0, stent struts exposed; Grade 1, struts bulging into the lumen, although covered; Grade 2, struts embedded in the neointima, but visible; Grade 3, struts fully embedded and invisible. Dominant neointimal coverage and heterogeneity grades were significantly higher in the middle and late phases than in the early phase (all P<0.05), but did not differ significantly between the middle and late phases. The incidence of thrombus adhesion was recorded for all stents in each of the 3 different phases. The middle and late phases after FP-DES implantation were associated with significantly higher dominant neointimal coverage and heterogeneity grades than the early phase. However, thrombus adhesion was observed in all phases after FP-DES implantation. Arterial healing may not be completed even in the late phase after FP-DES implantation.

Evaluation of Neointimal Coverage After Placement of a Flow Diverter Using Angioscopy.

HomeStrokeVol. 54, No. 2Evaluation of Neointimal Coverage After Placement of a Flow Diverter Using Angioscopy No AccessCase ReportRequest AccessFull TextAboutView Full TextView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissionsDownload Articles + Supplements ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toSupplemental MaterialNo AccessCase ReportRequest AccessFull TextEvaluation of Neointimal Coverage After Placement of a Flow Diverter Using Angioscopy Kenji Fukutome, MD, PhD, Mikio Shiba, MD, PhD, Ryuta Matsuoka, MD, PhD, Shuta Aketa, MD, PhD and Yasushi Motoyama, MD, PhD Kenji FukutomeKenji Fukutome Correspondence to: Kenji Fukutome, MD, PhD, Department of Neurosurgery, Osaka Police Hospital, 10-31 Kitayama-cho, Tennoji-ku, Osaka 543-0035, Japan. Email E-mail Address: [email protected] https://orcid.org/0000-0001-9533-9709 Department of Neurosurgery (K.F., R.M., S.A., Y.M.), Osaka Police Hospital, Japan. Search for more papers by this author , Mikio ShibaMikio Shiba https://orcid.org/0000-0003-4418-7834 Cardiovascular Division (M.S.), Osaka Police Hospital, Japan. Search for more papers by this author , Ryuta MatsuokaRyuta Matsuoka Department of Neurosurgery (K.F., R.M., S.A., Y.M.), Osaka Police Hospital, Japan. Search for more papers by this author , Shuta AketaShuta Aketa Department of Neurosurgery (K.F., R.M., S.A., Y.M.), Osaka Police Hospital, Japan. Search for more papers by this author and Yasushi MotoyamaYasushi Motoyama https://orcid.org/0000-0003-1957-2124 Department of Neurosurgery (K.F., R.M., S.A., Y.M.), Osaka Police Hospital, Japan. Search for more papers by this author Originally published9 Jan 2023https://doi.org/10.1161/STROKEAHA.122.041912Stroke. 2023;54:e40–e41"Evaluation of Neointimal Coverage After Placement of a Flow Diverter Using Angioscopy." Stroke, 54(2), pp. e40–e41FootnotesFor Sources of Funding and Disclosures, see page e41.Supplemental Material is available at https://www.ahajournals.org/doi/suppl/10.1161/STROKEAHA.122.041912.Correspondence to: Kenji Fukutome, MD, PhD, Department of Neurosurgery, Osaka Police Hospital, 10-31 Kitayama-cho, Tennoji-ku, Osaka 543-0035, Japan. Email [email protected]com Previous Back to top Next FiguresReferencesRelatedDetails February 2023Vol 54, Issue 2 Advertisement Article InformationMetrics © 2023 American Heart Association, Inc.https://doi.org/10.1161/STROKEAHA.122.041912PMID: 36621822 Originally publishedJanuary 9, 2023 Keywordsangioscopeaneurysmcone-beam computed tomographyinternal carotid arteryPDF download Advertisement SubjectsCerebral AneurysmClinical StudiesImagingStentVascular Biology

Evaluation of safety and performance of a new prototype self-expandable nitinol venous stent in an ovine model

ObjectiveOur study was a prospective in vivo study performed on an animal model to evaluate the safety and performance of a novel venous stent designed specifically for venous applications. MethodsThe novel stents were implanted in the inferior vena cava of nine sheep. The stents were deployed with different distances between the closed cell rings to test for if the segments might migrate after being deployed at maximal distance. Three different total lengths were 9, 11, and 13 cm. After 1, 3, and 6 months, vascular injury, thrombus, neointima coverage, and stent migration were evaluated through computed tomography venography and histopathology. Imaging, histology, and integration data were analyzed for each group. ResultsAll stents were deployed successfully, and all sheep survived until the time of harvesting. In all cases, the native blood vessel sections were intact. The segmented stent parts showed a differently pronounced tissue coverage, depending on the duration of the implantation. ConclusionsThe new nitinol stent is safe and feasible to implant in the venous system with a rapid surface coverage. Alteration of stent length did not affect the development of neointimal formation and did not cause migration.

Abstract 9613: Short- and Long-Term Vascular Responses of Stent With Biodegradable Graft for Artery Dissection in Rabbit Iliac Model

Introduction: Arterial dissection or rupture during percutaneous angioplasty is rare but can be lethal. We invented a balloon-expandable stent with a very thin membrane typed biodegradable graft for the treatment of arterial dissection (BioGard). Hypothesis: The efficacy and safety of BioGard were evaluated in the rabbit iliac artery rupture model. The devices would be helpful to seal the emergent blood extravasation due to arterial perforation and reduce unfavorable vascular events in long-term follow-up. Method: Twenty iliac arterial dissections by balloon over-inflation were induced under the guidance of angiography. Twelve rabbits with huge contrast extravasation to retroperitoneal space (Ellis type 3) were treated using BioGards. Serial histologic examinations and micro-computed tomography (CT) were performed at 1, 2, and 8 weeks and 3, 6, 9, and 12 months. Final angiography at 1 year was performed to evaluate any vascular complication. Results: There are no significant adverse cardiovascular events after one year of BioGard implantation. Micro-CT and follow-up angiography at one year revealed no case of significant in-stent restenosis and thrombotic occlusion in vivo. Early-stage histologic examination demonstrated that disrupted vessels were completely sealed up by BioGard with mural hematoma, inflammatory cell infiltration, and red thrombi. Mid- and long-term histologic examination revealed patent stents and neointimal coverage over the stents with biodegraded graft material and mild peri-strut area inflammatory response. Conclusions: Twelve months post-BioGard implantation in rabbit iliac artery dissections demonstrated good efficacy and safety. BioGard at a severely dissected artery would be an option for preventing lethal vascular events. Further clinical evaluation of this novel technology would be warranted.

Serial observation of PK Papyrus covered stent implantation for coronary artery perforation by optical coherence tomography and coronary angioscopy: a case report

Abstract Background Coronary artery perforation is a rare but life-threatening complication of percutaneous coronary intervention. We present a case of coronary artery perforation treated with a PK Papyrus covered stent. Neointimal coverage evaluation was performed using optical coherence tomography (OCT) and coronary angioscopy (CAS) at 3 and 9 months after stent implantation. Case summary A 63-year-old man was admitted to our hospital with worsening effort angina over 3 months. Coronary angiography revealed severe stenosis in the proximal segment of the left anterior descending artery. After stent implantation, coronary artery perforation occurred. We immediately sealed the perforation site using a PK Papyrus covered stent. The patient was discharged on postoperative day 4. OCT and CAS revealed incomplete neointimal coverage at the PK Papyrus covered stent strut 3 months after stent implantation. At 9 postoperative months, complete neointimal coverage was observed. We continued clopidogrel and edoxaban, but no clinical adverse events were encountered during the follow-up. Discussion To the best of our knowledge, this is the first report of a serial observation of PK Papyrus covered stent implantation for coronary artery perforation using OCT and CAS. In this case, OCT and CAS revealed complete neointimal coverage, without obvious thrombus, 9 months after PK Papyrus implantation. Based on the OCT and CAS findings, our report presents an appropriate follow-up strategy for the prevention of stent thrombosis when using a PK Papyrus covered stent, which will contribute to future research on the appropriate duration of dual antiplatelet therapy and evaluation of neointimal coverage.

Determinants of neointimal strut coverage in bio-degradable polymer coated ultrathin strut stent

Abstract Introduction Incomplete strut coverage (ISC) is the most important morphometric determinant of stent thrombosis. Determinants of ISC have been studied in thick and thin strut stents. Purpose To identify morphometric factors causing ISC in the biodegradable polymer-coated ultra-thin strut drug eluting stent (BP-UTS-DES) that are designed to encourage better strut coverage. Methods Patients undergoing implantation of a 65μm BP-UTS-DES had opportunistic OCT during staged PCI to assess strut coverage at 90 days. Images were analysed offline by experienced operators blinded to patient and procedural data. Neointimal thickness (NIT, μm) was measured as the minimum endoluminal distant between the strut and lumen border. All malapposed struts were considered uncovered. ISC was defined as &amp;lt;100% covered struts in a frame. Stepwise logistic regression using multiple morphometric variables was used to identify independent determinants of ISC including markers of circumferential distribution of neointimal growth (CVS,NUS,RUS), symmetry of stent expansion (SEI, AVS, MAS) in each cross section and the geographical location of the frame along the axis of the stent. Results We analysed 11652 frames of 65 stents (1976 mm) in 46 arteries of 40 patients. All stents were post dilated. 95.6% arteries had &amp;gt;20mm stents, 39.1% were overlapped and 15.2% were chronic total occlusions. Malapposition was seen in 2.6% of all struts and 39.2% of uncovered struts. The proportion of covered struts decreased as indices of circumferential uniformity of distribution of neointimal hyperplasia increased (CVS: r=0.37, p&amp;lt;0.001; RUS: r=0.36, p&amp;lt;0.001; NUS: r=0.52, p&amp;lt;0.001). As uniformity of stent expansion improved (SEI increased) strut coverage and circumferential uniformity of neointimal hyperplasia increased (CVS, NUS and RUS decreased) suggesting that distribution of neointimal growth becomes homogeneous as uniformity of stent expansion improves (Fig. 1). Determinants ISC is shown in Table 1. Conclusion SEI but not AVS or MAS determines ISC. Compared to the distal third of the stent frames in the middle third had lower and the proximal third had high risk of ISC. Funding Acknowledgement Type of funding sources: None.