Proximal Edge Research Articles

Association between stent implantation results and target vessel failure after IVUS-Guided PCI: A FLAVOUR substudy

Abstract Background Despite substantial advancements in coronary stent systems and implantation techniques, target vessel failure (TVF) remains a clinical issue to be addressed. Purpose We used deep learning algorithms for automatic stent analysis of intravascular ultrasound (IVUS) data to identify stent implantation characteristics associated with TVF. Methods In patients from the IVUS-guided group of the FLAVOUR trial who had undergone successful stenting, validated deep learning algorithms were applied to IVUS images to delineate plaque and stent strut for the quantification of stent expansion, apposition, and residual plaque burden. Stent overexpansion was defined as stent area exceeding 120% of the hypothetical healthy lumen area. Murray law-based quantitative flow ratio (μQFR) was also assessed from angiographic images. The primary endpoint was TVF at 2 years, defined as a composite of cardiac death, target vessel-related myocardial infarction, and ischemia-driven target vessel revascularization. Results A total of 459 vessels in 441 patients were included, with TVF events occurred in 15 vessels (3.3%) during the 2-year follow-up. Stent analysis was performed in 687,379 stent struts from 70,369 IVUS image frames of the interrogated vessels with the assistance of specific deep learning algorithms. On vessel-level multivariate analysis adjusting for procedural covariates, stent overexpansion length >5 mm (hazard ratio, 4.57; 95% confidence interval [CI], 1.31 to 15.92; P=0.017), residual plaque burden at proximal stent edge >50% (hazard ratio, 3.34; 95% CI, 1.19 to 9.33; P=0.022), and post-PCI μQFR <0.90 (hazard ratio, 5.09; 95% CI, 1.62 to 15.97; P=0.005) were more likely to be present in vessels with TVF events than in those without. Conclusions Besides the established indexes of post-procedural residual plaque burden and low μQFR, deep learning-powered IVUS stent overexpansion was significantly associated with increased risk of TVF.Suboptimal stenting results and TVF

Coronary stent edge segments as determinant of clinical outcomes: An OCTOBER Trial Substudy

Abstract Background Small lumen dimensions and high plaque burden in stent edge segments are known risk factors for subsequent clinical events after percutaneous coronary intervention (PCI). The evidence using intravascular optical coherence tomography is scarce. Purpose This study aimed to characterize edge segments after PCI and the relation to clinical outcomes in the randomized OCTOBER trial on bifurcation PCI optimized using optical coherence tomography. Methods This is a predefined substudy of the OCTOBER Trial. Edge segments were analysed in detail for degree of stenosis and plaque composition using a dedicated software. Data was planned to be analysed using multi-level cox regression analysis, but descriptive statistics was applied due to very low event rates after OCT-guided PCI. Main endpoints were OCT-detected edge residual stenosis, lipid plaque, calcification, and dissections. Post PCI coronary angiography was analysed for diameter stenosis, edge segment length and minimal lumen diameter. Patients with cardiac events were diagnosed with angiography duringt the two-year follow-up period. Results A total of 597 patients were treated with OCT-guided PCI. Analysable final OCT scans with no additional treatment was available for 505 patients in the main vessel and for the side branch in 289 cases. At deadline for abstract submission 242 scans with 474 edges were analysed and included in preliminary results.Lesions with ≥30% diameter stenosis was found in 20% of proximal edges, 24% of distal edges and 37% of side branch (SB) edges. A plaque burdenOCT ≥180° was found in 74% of proximal edges, 48% of distal edges, and 52% of SB edges. A lipid plaque wafound in 35%, 11% and 14%, dissections in 15%, 6% and 12%, and ≥180° calcium was found in 7%, 4% and 4% of edges respectively. Six patients (1%) of the total OCT-guided population had an edge-related event during the median two-year follow-up. Only two of these 6 patients had post-procedural OCT-scans of the event-related edge, thus 4 of the cases were effectively angiographic guided. Conclusion Only a small fraction of edge segments in the OCTOBER Trial were left with residual edge disease exceeding protocol thresholds. This resulted in historically very low rate of edge related events. No evaluation of a stent edge by OCT in otherwise OCT guided patients appeared to be the main predictor of edge related events. Final results are presented at ESC 2024.

Intraoperative contrast-enhanced cone beam CT allows visualization of the ‘dark side’ of the clot and improves mechanical thrombectomy performance

BackgroundVisualization of the clot is key to the endovascular treatment of ischemic stroke, but identification of the distal part of the clot and distal arteries during mechanical thrombectomy (MT) remains...

Impact of Significant Sac Shrinkage on Endograft Tortuosity at 5 Years Post-EVAR: A Retrospective Analysis

Significant sac shrinkage after endovascular aortic aneurysm repair (EVAR) is generally considered a positive outcome indicative of durable clinical success. However, its impact on endograft configuration is rarely addressed. Sac remodeling and volume loss due to shrinkage can potentially cause deformation of endograft components, resulting in limb angulation and compression. We investigated the hypothesis that significant sac shrinkage could affect endograft tortuosity at 5 years post-EVAR. We retrospectively reviewed patients who underwent elective EVAR for infrarenal abdominal aortic aneurysm between June 2007 and December 2018. Patients with early postoperative and 5-year follow-up CT images were included. Patients treated with modular bifurcated endografts (Zenith, Endurant, Excluder, and Incraft) were analyzed. The "shrinkage" group comprised patients with >10mm diameter reduction, while the "stable" group had ±5mm diameter change at 5 years. Tortuosity index (TI) was calculated as the ratio of centerline distance to straight-line distance between proximal and distal endograft edges. The association between sac shrinkage and ≥5% increase of TI (≥5%ΔTI) was analyzed for both ipsilateral and contralateral sides. Of 136 patients enrolled, 80 were in the shrinkage group and 56 in the stable group. On the ipsilateral side, ≥5%ΔTI was observed in 24 cases (17.6%). Patients with ipsilateral ≥5%ΔTI had significantly shorter median neck lengths (22mm vs 30mm, p = 0.030). Sac shrinkage ≥15mm was negatively associated with ≥5%ΔTI compared to stable sac (p = 0.027). Logistic regression showed sac shrinkage ≥15mm had a significant negative correlation with ≥5%ΔTI (p = 0.025, HR [95% CI] 0.218 [0.057-0.824]). On the contralateral side, ≥5%ΔTI (19 cases, 14.0%) was associated with shorter neck length but not with sac shrinkage. In the shrinkage group, cross-leg positioning resulted in a significant increase in ipsilateral TI at 5 years compared to straight positioning (median ΔTI: 1.8% vs 0.0%, p = 0.013). No reinterventions for leg-related events were necessary during the 5-year follow-up period. Contrary to our initial hypothesis, significant sac shrinkage does not adversely affect endograft configuration and may help stabilize tortuosity on the ipsilateral side. However, in patients with crossed-leg configuration, continued vigilant observation may be warranted even after achieving sac shrinkage, as it could exacerbate tortuosity. Shorter neck length was associated with increased tortuosity on both sides. Further research is needed to confirm these findings and consider potential confounding factors, including the impact of different endograft designs.

A New Bailout Maneuver to Manage Type IIIa Endoleak Due to Displaced Renal Bridging Stent Graft in Narrow Aorta.

To present endovascular management of an intraoperative type IIIc endoleak (EL) in a patient with migration of the right renal artery (RRA) bridging stent graft (BSG) during branched aortic aneurysm repair. The technique is demonstrated in an 80-year-old woman who underwent branched endograft repair of a symptomatic 6-cm type II TAAA. The t-Branch thoracoabdominal stent graft was positioned without difficulty. A "partial graft deployment" was performed, with the distal portion of the device remaining inside the delivery system and the right renal and superior mesenteric arteries were stented. When the constraining wires were removed, the RRA BSG migration from the branch was displayed, due to endograft twisting resulting in a horizontal rotation of the t-Branch. The RRA BSG remained oriented upward with the proximal edge positioned above the distal edge of the directional branch, making cannulation very difficult. This bailout technique uses a balloon placed at the level of the RRA BSG through the celiac artery (CA) directional branch; keeping the balloon inflated and in thrust, the edge of the BSG has moved downward making it possible to engage it and relining through the RRA directional branch. This paper describes an endovascular bailout technique for relining a displaced bridging stent graft, oriented upwards with the proximal edge positioned above the distal edge of the directional branch. This sophisticated technique adds to the spectrum of bailout techniques that can be applied in cases of type IIIa EL with migration and complete separation of BSG.

Exploring the Link Between Calcaneal Apophysis Maturation and Heel Pain in Youth Baseball Players.

Calcaneal apophysitis is the most common cause of heel pain in children and adolescents. However, the relationship between skeletal maturity and heel pain in the specific youth cohort is unclear. To clarify the relationship between the maturity stages of the calcaneal apophysis and heel pain in youth baseball players. Cross-sectional study; Level of evidence, 3. A total of 336 youth male baseball players participated in this study. Ultrasound scanning of the calcaneal apophysis was performed along the longitudinal line connecting the middle of the Achilles tendon, the middle of the calcaneus, and the second toe, between the proximal calcaneal edge and the medial calcaneal tubercle. The authors classified the maturity of the calcaneal apophysis into 5 stages, from nonpresence of the apophysis (stage 1) to complete fusion (stage 5). The diagnosis of heel pain was based on subjective report of feeling pain on the squeeze test. The relationship between the maturity stages and physical characteristics was investigated using 1-way analysis of variance or the Kruskal-Wallis test, and the relationship between the maturity stages and heel pain was investigated using the chi-square test. Of the 336 players, 49 had heel pain, for a prevalence of 14.6%. Eighteen (5.4%) players had unilateral heel pain, and 31 (9.2%) players had bilateral heel pain. There were no significant differences in the maturity stages of the calcaneal apophysis between the players with no heel pain and those with heel pain. However, no players had heel pain during stage 5, when the calcaneus had completed its maturation. The prevalence of heel pain was 14.6% in Japanese youth male baseball players. There was no relationship between the maturity stages of the calcaneal apophysis and heel pain. Heel pain that could be associated with calcaneal apophysitis did not occur during stage 5, when maturation of the calcaneal apophysis was complete.

Optical frequency domain imaging-guided versus intravascular ultrasound-guided percutaneous coronary intervention for acute coronary syndromes: the OPINION ACS randomised trial.

The clinical benefits of optical frequency domain imaging (OFDI)-guided percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) remain unclear. We sought to compare intravascular ultrasound (IVUS)- and OFDI-guided PCI in patients with ACS. OPINION ACS is a multicentre, prospective, randomised, non-inferiority trial that compared OFDI-guided PCI with IVUS-guided PCI using current-generation drug-eluting stents in ACS patients (n=158). The primary endpoint was in-stent minimum lumen area (MLA), assessed using 8-month follow-up OFDI. Patients presented with ST-segment elevation myocardial infarction (55%), non-ST-segment elevation myocardial infarction (29%), or unstable angina pectoris (16%). PCI procedural success was achieved in all patients, with comparably low periprocedural complications rates in both groups. Immediately after PCI, the minimum stent area (p=0.096) tended to be smaller for OFDI versus IVUS guidance. Proximal stent edge dissection (p=0.012) and irregular protrusion (p=0.03) were significantly less frequent in OFDI-guided procedures than in IVUS-guided procedures. Post-PCI coronary flow, assessed using corrected Thrombolysis in Myocardial Infarction frame counts, was significantly better in the OFDI-guided group than in the IVUS-guided group (p<0.001). The least squares mean (95% confidence interval [CI]) in-stent MLA at 8 months was 4.91 (95% CI: 4.53-5.30) mm2 and 4.76 (95% CI: 4.35-5.17) mm2 in the OFDI- and IVUS-guided groups, respectively, demonstrating the non-inferiority of OFDI guidance (pnon-inferiority<0.001). The average neointima area tended to be smaller in the OFDI-guided group. The frequency of major adverse cardiac events was similar. Among ACS patients, OFDI-guided PCI and IVUS-guided PCI were equally safe and feasible, with comparable in-stent MLA at 8 months. OFDI guidance may be a potential option in ACS patients. This study was registered in the Japan Registry of Clinical Trials (jrct.niph.go.jp: jRCTs052190093).

Outcomes of a Novel Single Branched Aortic Stent Graft for Treatment of Type B Aortic Dissection

Intervention on Type B dissection frequently requires landing the proximal edge of the stent graft between the left common carotid artery and left subclavian artery (LSA). The Gore® TAG® Thoracic Branch Endoprosthesis (TBE) is a technology which allows LSA preservation with a single internal branch. This study was a prospective non-randomized single-arm clinical trial of patients with type B aortic dissection that were treated with the single branched device. Patients with operative indications for acute, chronic or residual Type B dissections that originated distal to the origin of a left subclavian artery suitable for branch graft placement were eligible for the study. Native aortic and surgical graft proximal landing zones were eligible. Among the 132 patients, there were 25 (18.9%) acute type B dissections, 79 (59.8%) of chronic type B dissections and 28 (21.1%) of residual dissections after previous open Type A repair. Percutaneous access was used in 105 (79.5%) patients. Overall, 30-day mortality occurred in 6 patients (4.5%). The overall 30 day stroke rate was 2/132(1.5%) and the one-year freedom from stroke was 96.8%. Device Technical Success and Procedural Success was achieved in 129/132(97.7%) and 110/132(83.3%) of subjects, respectively and there was one instance of loss of side branch patency. There was no persistent antegrade false lumen flow observed. In this study of a novel branched endograft device to preserve the LSA in patients with type B dissection undergoing TEVAR, we demonstrate acceptable safety and efficacy outcomes at one year.

The Foraminal Indices of the Rat Scapula.

The nutritive arteries of bones may be injured due to fracture or surgical procedures. Therefore, there are some studies focused on the location of the nutrient foramen (NF) of bones. Rats are the most preferred animals in experimental studies. The purpose of this study is to expose the locational variations of the NF on the rat (Sprague Dawley) scapula. A total of 60 adult rat scapulae (from 16 male and 14 female rats) were used. The diameters of NFs were measured. The length, width, and distances of the NF to the proximal and cranial edges were measured. Foraminal indices were also calculated. It was determined that the average number of NF per scapula was 1.8. The location of the NFs was 52% on the medial aspect and 48% on the lateral aspect. On the medial aspect of the scapula, NFs were frequently found ventrally, on the neck region of the scapula. Laterally, 40 NFs were found in the ventral region of the infraspinatus fossa and only 12 in the ventral region of the supraspinatus fossa. Longitudinal foraminal index 95% confidence intervals were 74.25-79.18 (lateral) and 71.70-75.97 (medial). Transversal foraminal index 95% confidence intervals were 40.98-45.02 (lateral) and 42.91-46.07 (medial). Diameter of the NF 95% confidence interval was 0.21-0.39 mm. The locational knowledge of the NF can be utilized in anatomical or experimental surgery studies. The cranial and proximal edges of the rat scapula may be palpable; surgeons may palpate these regions and easily evaluate the location of the NFs.

The effect of the distance between mesh and the urethra on sexual function in patients who underwent transobturator tape

To evaluate the effect of mesh-urethra distance on sexual function in continent patients who underwent transobturator tape (TOT) surgery due to isolated stress urinary incontinence (SUI). Continent patients who had undergone TOT surgery for SUI were eligible. Objective treatment for SUI was defined as the absence of urine leakage during a stress test. Translabial perineal ultrasound was performed six months after surgery. The successful surgical group was split into two subgroups based on the distance from the posterior of the urethra at the bladder neck to the nearest proximal edge of the tape: <5 mm and >5 mm. In addition to these, band percentile, the descent of bladder neck and urethra length measured by perineal ultrasound, pubo-urethral distance, urethral thickness, detrusor thickness, cystocele descent, rectal descent, and uterine descent were evaluated. Preoperative and postoperative results of the standardized and internationally valid incontinence questionnaires Incontinence Questionnaire Urinary Incontinence Short Form and Female Sexual Function Index (FSFI) were compared between groups. Eighty-two patients were included. The postoperative FSFI scores for the >5 mm group were significantly lower than those of the <5 mm group, including the postoperative FSFI average, all subscales except lubrication, and average change scores due to the operation (p<0.001). There was no statistically significant relationship between the percentile occupied and postoperative FSFI score (p=0.553), and the FSFI preoperative-postoperative difference was not significant (p=0.905). Sexual functions are more affected in patients with a mesh-urethra distance >5 mm as measured by perineal ultrasound.

Optical coherence tomography predictors of clinical outcomes after stent implantation: the ILUMIEN IV trial.

Observational registries have suggested that optical coherence tomography (OCT) imaging-derived parameters may predict adverse events after drug-eluting stent (DES) implantation. The present analysis sought to determine the OCT predictors of clinical outcomes from the large-scale ILUMIEN IV trial. ILUMIEN IV was a prospective, single-blind trial of 2487 patients with diabetes or high-risk lesions randomized to OCT-guided versus angiography-guided DES implantation. All patients underwent final OCT imaging (blinded in the angiography-guided arm). From more than 20 candidates, the independent OCT predictors of 2-year target lesion failure (TLF; the primary endpoint), cardiac death or target-vessel myocardial infarction (TV-MI), ischaemia-driven target lesion revascularization (ID-TLR), and stent thrombosis were analysed by multivariable Cox proportional hazard regression in single treated lesions. A total of 2128 patients had a single treated lesion with core laboratory-analysed final OCT. The 2-year Kaplan-Meier rates of TLF, cardiac death or TV-MI, ID-TLR, and stent thrombosis were 6.3% (n = 130), 3.3% (n = 68), 4.3% (n = 87), and 0.9% (n = 18), respectively. The independent predictors of 2-year TLF were a smaller minimal stent area (per 1 mm2 increase: hazard ratio 0.76, 95% confidence interval 0.68-0.89, P < .0001) and proximal edge dissection (hazard ratio 1.77, 95% confidence interval 1.20-2.62, P = .004). The independent predictors of cardiac death or TV-MI were smaller minimal stent area and longer stent length; of ID-TLR were smaller intra-stent flow area and proximal edge dissection; and of stent thrombosis was smaller minimal stent expansion. In the ILUMIEN IV trial, the most important OCT-derived post-DES predictors of both safety and effectiveness outcomes were parameters related to stent area, expansion and flow, proximal edge dissection, and stent length.

Functional Morphology and Ultrastructure of the Peripheral Antennal Sensillar System of Graphosoma italicum (Müller, 1766) (Insecta: Hemiptera: Pentatomidae).

The antennae of the shield bug Graphosoma italicum (Müller, 1766) were examined through scanning and transmission electron microscopy to reveal their general morphology, as well as the antennal sensilla's distribution, size, and ultrastructure of their dendrites and function. The antennae comprise five antennomeres (one scape, two pedicels, and two flagellomeres). Different lengths of chaetic mechanosensilla (Ch1-Ch4) exist on all antennomeres, and several highly sensitive campaniform sensilla are embedded in the exoskeleton and measure cuticular strain. One pair of peg sensilla, the typical proprioceptive, is only on the proximal edge of the first pedicel and directed to the distal edge of the scapus. The antennal flagellum possesses two subtypes of trichoid and basiconic sensilla, each with one type of coeloconic olfactory sensilla. The distinctive characteristics of G. italicum are also apparent in two subtypes of coeloconic sensilla embedded in different cavities on both antennomeres of the flagellum, probably with a thermo-hypersensitive function. All studied morphological types of the sensilla and their function were supported by ultrastructural elements. The long and thin trichoid sensilla type 2 (TrS2) with an olfactive function was the most abundant sensilla localized on both flagellomeres. The peripheral antennal sensilla system consists of six main types of sensilla divided into twelve subtypes.

Olecranon Osteotomy Exposure for Distal Humeral Fracture Treatment.

Olecranon osteotomy (OO) is commonly utilized to improve exposure when treating intra-articular distal humeral fractures. A chevron-shaped osteotomy facilitates reduction and increases surface area for healing1. Following distal humeral fracture reduction and fixation, the OO fragment is fixed with a precontoured plate. The OO technique yields comparable outcomes to alternative techniques1,2. The technique is performed as follows. (1) Imaging is reviewed and preoperative planning is performed. (2) The patient is positioned in the lateral decubitus position with the operative extremity placed over a bolster. (3) A longitudinal posterior skin incision is centered just medial or lateral to the tip of the olecranon. Full-thickness skin flaps are raised medially and laterally. (4) The ulnar nerve is identified and mobilized for later anterior subcutaneous transposition. (5) An OO is performed at the non-articular "bare area" of the trochlear notch with an oscillating saw and completed with an osteotome. (6) Open reduction and internal fixation of the distal humerus is performed. (7) The osteotomy fragment is reduced, and a precontoured plate is applied. (8) A small longitudinal slit in the distal triceps over the proximal edge of the plate decreases plate prominence and is repaired with suture. (9) The subcutaneous tissues and skin are closed in the usual manner. Alterative techniques include extra-articular OO, triceps splitting, triceps reflecting, and lateral para-olecranon combined with a medial approach. Multiple drill holes and a thin osteotome can help mitigate the kerf created by the oscillating saw. Alternative fixation methods include a predrilled 6.5-mm intramedullary screw, a tension band construct, suture fixation, or a one-third tubular plate. The OO technique provides improved exposure when compared with alternative techniques, enabling accurate reduction and fixation of distal humeral fractures1-3. Wilkinson and Stanley found that OO exposed the distal humeral articular surface to a greater degree than the triceps-splitting and triceps-reflecting approaches3. OO has not been associated with triceps weakness, unlike some of the alternative techniques2. The incidence of good-to-excellent outcomes is similar when comparing the techniques for exposure of intra-articular distal humeral fractures4. Osteotomies united in all patients in 2 reported series, totaling 84 cases1,2. Removal of symptomatic hardware used in OO fragment fixation can occur in a small subset of patients1,2. Provisionally size a precontoured plate and fix it on the olecranon to aid in later reduction and fracture fixation.The bare area is the desired position for the OO because of its natural lack of cartilage5,6. This non-articular bare area is located just distal to the deepest portion of the trochlear notch, approximately 2 to 2.5 cm distal to the olecranon tip5,6.An (apex-distal) chevron osteotomy angle of ∼130° will help to keep the osteotomy within the non-articular bare area6.Beginning on the dorsal surface of the ulna, directly posterior to the bare area, an oscillating saw is utilized to create a chevron osteotomy to subchondral bone, perpendicular to the long axis of the ulna5,6.The OO is completed by fracturing through the osteochondral surface, which leaves an irregular chondral cancellous surface that can accurately interdigitate. This facilitates later reduction and stability of the osteotomy.Anatomic articular reduction of the OO is not solely judged on the dorsal cortical bone because of the kerf removed by the saw blade. Instead, examination of the articular surface of the trochlear notch is the primary assessment of reduction.Placement of suture through the proximal portion of the plate aids in the repair of the longitudinal split of the distal triceps.Successful treatment of distal humeral fractures requires accurate reduction and rigid fixation aided by adequate exposure achieved through OO. ORIF = open reduction and internal fixationOT = occupational therapyHWR = hardware removalK-wire = Kirschner wireROM = range of motion.

Enhanced Wireless Communication Optimization with Neural Networks, Proximal Policy Optimization and Edge Computing for Latency and Energy Efficiency

This research proposes a novel approach for efficient resource allocation in wireless communication systems. It combines dynamic neural networks, Proximal Policy Optimization (PPO), and Edge Computing Orchestrator (ECO) for latency-aware and energy-efficient resource allocation. The proposed system integrates multiple components, including a dynamic neural network, PPO, ECO, and a Mobile Edge Computing (MEC) server. The experimental methodology involves utilizing the NS-3 simulation platform to assess latency and energy efficiency in resource allocation within a wireless communication network, incorporating an ECO, MEC server, and dynamic task scheduling algorithms. It demonstrates a holistic and adaptable approach to resource allocation in dynamic environments, showcasing a notable reduction in latency for devices and tasks. Latency values range from 5 to 20 milliseconds, with corresponding resource utilization percentages varying between 80% and 95%. Additionally, energy-efficient resource allocation demonstrates a commendable reduction in energy consumption, with measured values ranging from 10 to 30 watts, coupled with efficient resource usage percentages ranging from 70% to 85%. These outcomes validate the efficacy of achieving both latency-aware and energy-efficient resource allocation for enhanced wireless communication systems. The proposed system has broad applications in healthcare, smart cities, IoT, real-time analytics, autonomous vehicles, and augmented reality, offering a valuable solution to optimize energy consumption, reduce latency, and enhance system efficiency in these industries.

Lower extremity woven and nonwoven venous stent morphology and luminal changes

ObjectiveVenous stents are a common treatment modality for obstructive venous disease. Venous stents differentiate themselves by either a woven or braided structure, open or closed cell arrangement or based on material composition (elgiloy vs nitinol). Changes in the morphology of venous stents over time may contribute to restenosis or thrombosis. Woven elgiloy stents are prone to proximal and distal edge deformation compared with dedicated venous stents, which offer increased radial force at stent edges. The objective of this study is to describe luminal morphological changes among various venous stents and between woven to nonwoven venous stent configuration, over time. MethodsA retrospective review at a single institution between January 2014 and June 2021 identified patients treated with venous stents. Patients with iliac and/or femoral venous stents with intraoperative intravascular ultrasound and a postoperative computed tomography scan were included in the study. Cross-sectional diameters measurements were taken at proximal, middle, and distal portions of each stent from intravascular ultrasound examination at the time of initial stenting and compared with the cross-sectional diameter measurements taken from computed tomography imaging at follow-up. A paired t test was used to compare the luminal change with a D'Agostino-Pearson test used for normality. ResultsFifty-four stents distributed among 38 patients were identified. The mean time to follow-up was 17.5 months. Stents were placed in the common iliac vein (n = 37, 68.5%), external iliac vein (n = 14, 25.9%), and common femoral vein (n = 3, 5.6%). Implanted stents included the Boston Scientific Wallstent (n = 23, 42.6%), Bard Venovo (n = 3, 5.6%), Boston Scientific Vici (n = 23, 42.6%), and Medtronic Abre (n = 5, 9.3%). The mean luminal loss was measured at 2.12 mm proximally (95% confidence interval [CI], 1.64-2.60; P<.001), 1.29 mm at the mid-stent (95% CI, 0.83-1.74, P<.001), and 1.56 mm distally (95% CI, 0.99-2.12; P<.001). There was no significant difference in luminal changes between woven and nonwoven stents at proximal (P = .374), middle (P = .179), and distal (P = .609) stent measurements. ConclusionsThis study reports morphological changes within venous stents and between woven and nonwoven venous stents. Our findings demonstrate that the edge-stent luminal decrease traditionally attributed to woven configurations also occurs with the newer nonwoven stents. Additional factors such as anatomical location, pelvic curvature, and other external forces may be accountable for this change rather than geometrical configuration of the stent.

Can micro-guidewire advancement forces predict clot consistency and location to assist the first-line technique for mechanical thrombectomy?

The identification of specific clot characteristics before mechanical thrombectomy (MTB) might allow the selection of the most effective first-line technique, thus potentially improving the procedural outcome. We aimed to evaluate if the microwire push forces could extrapolate information on clot consistency and extension before MTB, based on clot mechanical properties. We measured in vitro the forces exerted on the proximal extremity of the guidewire during the advancement and retrieval of the guidewire through clot analogs of different compositions. In addition, we analyzed the forces exerted on the guidewire to extrapolate information about the location of the proximal and distal extremities of the clot analogs. The maximum forces recorded during the whole penetration phase were significantly different for hard and soft clots (median values, 55.6 mN vs 15.4 mN, respectively; P<0.0001). The maximum slope of the force curves recorded during the advancement of the guidewire for the first 3 s of penetration also significantly differentiated soft from hard clot analogs (7.6 mN/s vs 23.9 mN/s, respectively; P<0.0001). In addition, the qualitative analysis of the shape of the force curves obtained during the advancement and retrieval of the guidewire showed a good potential for the identification of the proximal and distal edges of the clot analogs. Our results demonstrated that it was possible to differentiate between soft and hard clot analogs. Furthermore, force measurements could give important information about the location of the clot extremities. Such an approach might support the selection of the first-line MTB technique, with the potential to improve the outcome.

Association Between Automated 3D Measurement of Coronary Luminal Narrowing and Risk of Future Myocardial Infarction

This study focuses on identifying anatomical markers with predictive capacity for long-term myocardial infarction (MI) in focal coronary artery disease (CAD). Eighty future culprit lesions (FCL) and 108 non-culprit lesions (NCL) from 80 patients underwent 3D quantitative coronary angiography. The minimum lumen area (MLA), minimum lumen ratio (MLR), and vessel fractional flow reserve (vFFR) were evaluated. MLR was defined as the ratio between MLA and the cross-sectional area at the proximal lesion edge, with lower values indicating more abrupt luminal narrowing. Significant differences were observed between FCL and NCL in MLR (0.41 vs. 0.53, p < 0.001). MLR correlated inversely with translesional vFFR (r = − 0.26, p = 0.0004) and was the strongest predictor of MI at 5 years (AUC = 0.75). Lesions with MLR < 0.40 had a fourfold increased MI incidence at 5 years. MLR is a robust predictor of future adverse coronary events.Graphical The minimum lumen ratio (MLR) is defined as the ratio between the minimum lumen area (MLA) and the cross-sectional area at the proximal edge of the lesion (PROXA). A lower MLR suggests a more pronounced luminal narrowing upstream of the MLA. This specific anatomical lesion characteristic correlates with higher translesional pressure gradients and has been found to be highly predictive of lesion destabilization over a 5-year period. Notably, lesions exhibiting MLR values below 0.399 were associated with a fourfold increase in the incidence of myocardial infarction (MI) within the same timeframe.

Stent-induced new entry and device migration associated with hemodynamic stress after thoracic endovascular aortic repair for type B chronic aortic dissection using computational fluid dynamics analysis: a case report

BackgroundStent graft-induced new entry (SINE) after thoracic endovascular aortic repair (TEVAR) is a serious adverse event which leads to stent graft migration and rupture. SINE is known to be more frequent in cases of chronic dissection and oversizing. However, few studies have evaluated the influence of hemodynamic stress on SINE in patients with chronic dissection. Here, we report a rare case of TEVAR for chronic dissection with a dissection stent, inducing SINE 6 years after the first surgery. In addition, we analyze the hemodynamic stress for the aortic event using computational fluid dynamics (CFD) analysis.Case presentationA 69-year-old male underwent TEVAR with left subclavian artery debranching for chronic type B aortic dissection, using a stent graft and dissection stent. The postoperative course was uneventful, but follow-up computed tomography (CT) showed that the stent graft and bare-metal stent had dislodged 4 years after surgery. The gap between the bare-metal stent and the stent graft increased over time, and the proximal edge of the bare-metal stent led to SINE at the descending aorta 6 years after surgery. We performed reintervention to cover the SINE. The patient recovered well and was discharged at 6 days postoperatively. He is currently in good condition 6 months after reintervention. CFD analysis of the patient’s CT image suggested that the local change in wall shear stress at the stent graft and dissection stent might be related to the aortic event.ConclusionHemodynamic stress is a factor affecting SINE and device migration. CFD may be useful for evaluating patient-specific risk of aortic events.

Impact of stent strut link location in proximal balloon edge dilation technique for bifurcation percutaneous coronary intervention.

The single-stent strategy has generally been accepted as the default approach to bifurcation percutaneous coronary intervention. We have proposed the proximal balloon edge dilation (PBED) technique to prevent stent deformation during side branch (SB) dilation. This bench study aimed to evaluate the impact of stent link location and stent design on stent deformation, obstruction by stent struts at a jailed SB ostium, and incomplete stent apposition in the proximal optimization technique (POT)-PBED procedure. A coronary bifurcation model was used. We intentionally set the absence or presence of stent link on the carina (link-free or link-connect) under videoscope observation and compared stent parameters between 3- and 2-link stents (n = 5 each, n = 20 total). In the link-free group, the SB jailing rate of 3-link stents was significantly higher than that of 2-link stents (15.5 ± 5.1% vs. 6.6 ± 1.2%, p = 0.009). In the link-connect group, the SB jailing rate of 3-link stents was significantly lower than that of 2-link stents (30.0 ± 4.5% vs. 39.0 ± 2.6%, p = 0.009). In the bifurcation segment, the rate of incomplete stent apposition was significantly lower for 3-link stents of the link-connect group than for 2-link stents of the link-connect group (3.3 ± 4.2% vs. 19.0 ± 7.8%, p = 0.009). For both stent designs, ellipticity ratio was higher for link-connect group than link-free group. Link location as well as stent cell design greatly impacted stent deformation during the POT-PBED procedure.

Fabrication of a 3D printed everolimus-eluting stent made of thermoplastic polyurethane and polylactide

Bronchial stenoses are one of the most common airways complications after lung transplantation. One of the main methods to restore airway patency is bronchial stenting. However, bronchial stenting is associated with a number of complications, such as stent migration, granulation tissue formation along the proximal and distal edges, and mucus obstruction of the lumen. This article demonstrates the possibility of manufacturing an everolimus-eluting stent from thermoplastic polyurethane and polylactide using 3D printing.