Stent Expansion Research Articles

Rota-Tripsy or step-up-approach rotational atherectomy for severe coronary artery calcification treatment: a comparative effectiveness study

Step-up-approach rotational atherectomy has been widely recognized in the treatment of severe calcified plaques. As an alternative, the rota-tripsy procedure is a novel strategy for the modification of calcification lesions. This study aimed to evaluate and compare the efficacy and safety of rota-tripsy and step-up-approach rotational atherectomy, given the limited clinical data available. Clinical data of 3652 patients with coronary calcification were retrospectively collected from February 2021 to February 2024. The cases were divided into two groups based on the technical approach. The primary efficacy endpoint was procedural success (stent expansion rate > 70% and no hospital major adverse cardiac events [MACEs]). The primary safety endpoint was the absence of serious angiographic complications and 30 days MACEs. A total of 37 patients (38 calcified lesions) screened and included in the study, with 18 cases (19 lesions) in group A and 19 cases in group B. The results showed no significant differences in primary efficacy endpoint. However, group A recorded a lower incidence of angiographic complications (P = 0.02) and shorter dose area product and fluoroscopy/interval times compared with group B (P < 0.01). For management of severe coronary calcification, both rota-tripsy and step-up-approach rotational atherectomy had favorable short-term clinical results; however, rota-tripsy provided improved safety and efficiency.

Outcomes of coronary intravascular lithotripsy for the treatment of calcified nodules: a pooled analysis of the Disrupt CAD studies.

Coronary intravascular lithotripsy (IVL) safely facilitates stent implantation in severely calcified lesions. This analysis sought to determine the relative impact of IVL on acute and long-term outcomes specifically in calcified nodules (CNs). Individual patient-level data (N=155) were pooled from the Disrupt CAD optical coherence tomography (OCT) substudies. Severely calcified lesions with and without CNs were compared by OCT for acute procedural results and for target lesion failure (TLF) at 2 years - a composite of cardiac death, target vessel myocardial infarction, and ischaemia-driven target lesion revascularisation. A CN was identified in 18.7% (29/155) of lesions. When comparing lesions with and without CNs, there were no significant differences in preprocedure minimal lumen area or diameter stenosis; however, the mean calcium angle and calcium volume were greater in CN lesions. Despite a higher calcium burden, the final minimal stent area (CN: 5.7 mm2 [interquartile range [IQR] 4.4, 8.3] vs non-CN: 5.7 mm2 [IQR 4.7, 7.2]; p=0.80) and stent expansion (CN: 79.3% [IQR 64.3, 87.0] vs 80.2% [IQR 68.9, 92.4]; p=0.30) were comparable between the two groups. In the CN group, the final stent area and expansion at CN sites were 7.6 mm2 (IQR 5.5, 8.5) and 89.7% (IQR 79.8, 102.5), respectively. The cumulative incidence of TLF at 2 years was 13.9% and 8.0% in the CN and non-CN groups, respectively (p=0.32). Despite a greater calcium volume in CNs, IVL use was associated with comparable stent expansion and luminal gain in both CN and non-CN lesions. Further studies powered for clinical outcomes comparing different plaque modification techniques in this lesion subset are warranted.

Abstract 4118076: Right Innominate Artery Endovascular Intervention Via Single Radial Access and Use Of Embolic Protection

Introduction: The occurrence of innominate artery stenosis is less prevalent compared to subclavian artery disease. Small studies suggest up to 8% of individuals initially diagnosed with suspected subclavian steal syndrome may present with innominate artery lesions. Deployment of an embolic protection filter within the internal carotid artery during percutaneous intervention of the innominate artery presents a solution to mitigate embolism. Case: A 70-year-old female with a history of peripheral vascular disease presented with claudication in both arms, manifested as pain in both arms. Her left subclavian was stented months prior to presentation. An aortogram revealed severe stenosis of the innominate artery (Figure 1). Since multiple attempts to cross the lesion antegrade from the femoral access site were unsuccessful, we proceeded with the successful deployment of an embolic protection filter in the right internal carotid artery via our right radial artery access site (Figure 2). Using the right radial artery, we passed a long run-through guidewire into the distal abdominal aorta. Due to severe aortic tortuosity, we were unable to snare the wire from the aorta. Therefore, we upsized the radial sheath to 7 French over both wires (runthrough and bare). Using a support catheter, we exchanged the runthrough wire for a Glidewire Advantage. We advanced an 8 x 29mm balloon expandable stent to the area of innominate stenosis and deployed it (Figure 3). We postdilated the stent with a 14mm balloon. Angiography demonstrated adequate expansion. On follow up, the patient was without claudication and had triphasic flow in the innominate and left subclavian arteries. Discussion: Treating innominate artery stenosis via radial access employing a sole entry point for both embolic protection and treatment administration offers a substitute where additional access is infeasible. Modern embolic protection techniques are superior due to their flexibility and ease of use. In this case, placing the embolic protection device in the carotid artery was mandatory through the sole radial access to prevent trapping the filter behind the innominate artery stent. We were able to perform both the embolic device placement and the stenting with the same radial access. Conclusion: Endovascular intervention of innominate artery stenosis via radial access, utilizing a single radial access for both embolic protection and treatment delivery, presents an alternative when femoral access is not feasible.

Computed tomography for prediction of stent underexpansion after percutaneous recanalization of calcified coronary chronic total occlusions

Abstract Background Coronary calcifications are the leading cause of stent underexpansion after percutaneous coronary intervention (PCI) and are commonly encountered in chronic total occlusions (CTO). Coronary computed tomography angiography (CCTA) is uniquely suited for pre-procedural assessment of coronary calcifications. Recently quantitative CCTA, providing exact volumes of each plaque component, has shown additional value in future risk assessment compared with conventional qualitative CCTA. Purpose The aim of this study was to evaluate whether CCTA predicts intravascular ultrasound (IVUS)-defined suboptimal stent expansion following percutaneous recanalization of calcified CTO lesions. Methods We retrospectively identified consecutive patients with a CCTA performed within 6-months prior to successful PCI of a calcified CTO (defined as calcification within the target lesion on CCTA). All patients had final IVUS of implanted stents (Figure 1). Patients requiring atherectomy were excluded. The primary outcome was IVUS-derived stent expansion index (SEI), defined as stent area divided by vessel area (both measured at the site of maximum calcium). SEI&amp;lt;0.4 indicated suboptimal stent expansion. The site of maximum calcium was a cross-section with greatest calcium arc on pre-stent IVUS within the target lesion. CCTA calcium analysis was performed by a researcher blinded to the IVUS and angiography results. Measurements included total-, vessel-, and lesion-specific calcium score (CAC), total calcium length, maximum calcium thickness and maximum CT calcium attenuation at the target lesion defined as occlusion site and adjacent severely diseased segments. Calcium quantification was performed using a semi-automated software to obtain volumes and burdens of calcified and non-calcified plaque components within the target lesion. Results The cohort included 43 patients (age 64.9±10.0 years, 88% males) with 43 CTO lesions. Mean final stent area at maximum calcium by IVUS was 8.2±2.1mm². Mean SEI was 0.47±0.1, and suboptimal SEI of &amp;lt;0.4 was found in 10 (23.3%) lesions. Lesions with suboptimal stent expansion (SEI&amp;lt;0.4) were characterized by numerically higher total-, vessel- and lesion-specific CAC, higher maximum calcium attenuation, greater calcium length and remodeling index compared with patients with optimal stent expansion (Table 1). However, only calcified plaque volume (105 [IQR 27-271] vs. 29 [4-96]mm³, P=0.02) and calcified plaque burden (16 [7-24] vs. 6 [1-10]%, P=0.03) were significantly greater in lesions with suboptimal stent expansion compared with lesions with optimal stent expansion, respectively. Calcified plaque volume ≥51 mm³ within the target lesion predicted suboptimal stent expansion with 70% sensitivity and 62.5% specificity (AUC 0.74). Conclusion CCTA-derived calcium volume identifies CTO lesions at greater risk of stent underexpansion. Such lesions require more aggressive plaque modification prior to stent implantation.

A meta-analysis of randomised controlled trials comparing optical coherence tomography-guided against angiography-guided revascularisation

Abstract Optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) offers more in-depth assessment of plaque morphology, vessel sizing and post-PCI stent deployment characteristics than angiography guidance alone. Previous studies have demonstrated superiority of OCT-guided compared to angiography-guided PCI in stent implantation and expansion, with no difference in safety outcomes. Despite this, adoption of OCT-guided PCI remains low in clinical practice due to its increased procedural time, larger contrast volume, and added cost. Two large multicentre international randomised controlled trials (RCTs) were recently published. We therefore aimed to perform an up-to-date meta-analysis of RCTs comparing OCT-guided revascularisation against angiography-guided revascularisation on hard clinical outcomes. A comprehensive search of PubMed/MEDLINE and Ovid/Embase was performed, of which only RCTs were included. Two authors identified relevant articles and extracted the data independently. Any disagreements were resolved by a third author. Clinical outcome data was extracted from each study and then pooled to determine the overall risk ratio (RR) and confidence interval (CI) collectively. This was calculated with random-effects model using the Mantel-Haenszel method. All reported P values are two-sided, with significance set at P&amp;lt;0.05. A total of ten RCTs involving a total of 5062 patients were included. After an average follow-up of 20 months, there was no significant difference in the trial-defined composite endpoint between OCT-guided versus angiography guided revascularisation [6.8% versus 7.9%, RR 0.85, 95% CI (0.69 to 1.03), P=0.10, heterogeneity (I2)=0%]. There was also no significant difference in cardiac death [1.0% versus 1.6%, RR 0.61, 95% CI (0.36 to 1.02), P=0.06, heterogeneity (I2)=0%, Figure 1a], myocardial infarction [3.2% versus 3.7%, RR 0.86, 95% CI (0.65 to 1.15), P=0.31, I2=0%, Figure 1b] and target lesion or vessel repeat revascularisation [3.8% versus 4.1%, RR 0.95, 95% CI (0.72 to 1.25), P=0.70, I2=0%, Figure 1c] between the two arms. However, the OCT-guided revascularisation arm was associated with a significantly lower rate of stent thrombosis [0.8% versus 1.5%, RR 0.57, 95% CI (0.33 to 0.97), P=0.04, I2=0%, Figure 1d] than the angiography-guided revascularisation arm. The number-needed-to-treat (NNT) by OCT-guided revascularisation to reduce one additional stent thrombosis event was 143. In conclusion, our findings show the use of OCT-guided revascularisation led to a significant reduction in stent thrombosis compared to angiography-guided revascularisation, but there was no difference in cardiac death, myocardial infarction and repeat revascularisation. The NNT for stent thrombosis was 143 patients. Further research is needed to identity those subgroups most likely to benefit from OCT-guided revascularisation before it can be more widely adopted to significantly impact on clinical care.

Reverse cardiac remodeling induced by endovascular treatment of coarctation of the aorta

Abstract Background Previously, we have showed the 3-year clinical safety and efficacy of balloon expandable versus self-expandable stents in native coarctation of the aorta (CoA) in a randomized clinical trial (RCT). Very few prospective studies have addressed the changes of echocardiographic parameters in mid to long-term follow up of CoA patients treated endovascularly. Purpose We aimed to demonstrate the improvement of echocardiographic parameters among patients undergoing coarctoplasty with stent based on core laboratory-confirmed baseline and 3-year follow up transthoracic echocardiographic (TTE) images. Methods In the index RCT, adult patients with de novo native CoA were randomized into two groups based on stent types. All randomized patients received the 3-year structural follow-up including aortic CT angiography and TTE. The current prospective cohort substudy, included all patients with available baseline and three-year core laboratory TTEs. Results Of 92 patients initially randomized, 71 participated in the 3-year structural follow up. No baseline core lab images were available in 39 patients, and thus, 32 patients (a median age of 32 (24.8 – 37.5) years, (14 women [43.8%]) were included in this subgroup study. One out of the 32 patients presented with recoarctation which was successfully treated before the 3-year evaluation. Peak systolic gradient and end-systolic velocity of the coarctation stenting site were 17.38 ± 6.55 mmHg and 0.93 ± 0.24 m/s respectively in the 3-year follow-up. Septal E’ and lateral E’ velocities were improved significantly (8.6 ± 1.73 cm/s to 9.35 ± 2 cm/s, P = 0.02 and 12.74 ± 2.96 cm/s to 13.92 ± 2.44 cm/s, P = 0.03, respectively). In addition, septal E/E’ ratio (10.84 ± 2.83 to 9.21 ± 3.17, P = 0.02) and lateral E/E’ ratio (7.39 ± 2.24 to 6.29 ± 1.97, P = 0.02) showed significant improvement. Significant reduction in LV mass [160 (130–203) g to 142 (IQR= 121–172) g, P = 0.001], and septal and posterior LV thicknesses were also demonstrated (0.9 (0.8–1.0) cm to 0.81 (0.77–0.93) cm, P = 0.004) and 0.92 ± 0.14 cm to 0.85 ±0.09 cm, P = 0.01, respectively). Twelve (37.5%) patients had baseline LVH which was normalized in 9 (75%). Lastly, 12 (41.3%) of our population had diastolic dysfunction at baseline study which significantly decreased to 4 (13.7%) in the three-year follow-up evaluation. Conclusion In the present core laboratory-based study, coarctoplasty with stent has favorable effects on diastolic function and LV hypertrophy during midterm follow-up in adult population with de novo native aortic coarctation treated with stent.

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 &amp;gt;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 &amp;gt;50% (hazard ratio, 3.34; 95% CI, 1.19 to 9.33; P=0.022), and post-PCI μQFR &amp;lt;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

Mid-Term Outcomes of the Iliac Branch Endoprosthesis with Standardized Combinations of Bridging Stent-Grafts for Endovascular Treatment of Aortoiliac Disease with or Without Co-existing Hypogastric Aneurysms (The HYPROTECT Study).

To evaluate retrospectively the 2-year outcomes of the Gore Excluder Iliac Branch Endoprosthesis (IBE) in patients with and without coexisting hypogastric artery (HA) aneurysms in a large contemporary multicentric European experience using dedicated bridging devices. The study included all consecutive patients treated at participating institutions with the Gore Excluder IBE device who received a covered stent (i.e., stent-graft) from the same manufacturer. Technical success was defined as deployment of endografts with complete exclusion of the aneurysm(s), patency of target vessels, and absence of type 1 and 3 endoleak. Assessment of follow-up outcomes included freedom from HA branch instability defined as the composite cumulative endpoint of any HA branch-related complication. A total of 437 patients were included for analysis from 22 European vascular surgery centers. Patients were categorized into two subgroups: subgroup A (n = 269) if they did not have concomitant hypogastric aneurysms, otherwise they were categorized into subgroup B (n = 168). Finally, 78 (18%) had bilateral IBE with a total of 515 IBE included in the study. Balloon expandable stents were deployed in 19 (6.3%) subgroup A patients compared with 46 (21.7%,) in subgroup B, p < .001. The two-year estimate for freedom of HA branch instability was significantly higher for patients in group A as compared with patients in group B (94% vs. 90%, p = .045). At univariate regression, the number of stent-grafts used was associated with higher risk of iliac branch instability (p = .021), while in multivariate regression for the use of more than 2 bridging stent-grafts the risk of instability increased by 2.35 times. This large contemporary European multicentric experience with the use of the Gore Excluder IBE in patients with or without associated HA aneurysms shows satisfactory mid-term outcomes when the device is used in conjunction with both self-expandable and balloon-expanding stent-grafts from the same manufacturer. Although primary patency of the iliac branch was as high as 90%, caution and strict follow-up must be exercised when multiple bridging stent-grafts are used over longer distances.

Interaction of a self-expandable stent with the arterial wall in the presence of hypocellular and calcified plaques.

Self-expandable stents manufactured from nitinol alloys are commonly utilized alongside traditional balloon-expandable stents to provide scaffolding to stenosed arteries. However, a significant limitation hampering stent efficacy is restenosis, triggered by neointimal hyperplasia and resulting in the loss of gain in lumen size, post-intervention. In this study, a nonlinear finite element model was developed to simulate stent crimping and expansion and its interaction with the surrounding vessel in the presence of a plaque. The main aim was to determine contact pressures and forces induced at the interface between an artery wall with hypocellular and calcified plaques and an expanded stent. The results demonstrated the drawbacks of plaque calcification, which triggered a sharp contact pressure and radial force surge at the interface as well as a significant rise in von Mises stress within the vessel, potentially leading to rupture and restenosis. A regression line was then established to relate hypocellular and calcified plaques. The adjusted coefficient of determination indicated a good correlation between contact pressures for calcified and hypocellular plaque models. Regarding the directionality of wall properties, contact pressure and force observations were not significantly different between isotropic and anisotropic arteries. Moreover, variations in friction coefficients did not substantially affect the interfacial contact pressures.

Hybrid Stent Graft Technique in Bridging Hostile Renal Arteries in Thoraco-abdominal Branched Endografting

Patency of target arteries is crucial for fenestrated and branched endovascular aortic repair (F/B-EVAR) in thoracoabdominal aortic aneurysms (TAAAs). Occlusions more frequently occur in renal arteries (RAs) than in coeliac and superior mesenteric arteries, especially in patients with hostile anatomy treated by BEVAR. This study aimed to report RA outcomes using a hybrid bridging stent graft technique with distal self expandable (SE) combined with proximal balloon expandable (BE) stent graft during BEVAR with hostile RA anatomies. Clinical data from consecutive patients treated for TAAA by F/B-EVAR in three aortic centres (two in the USA, one in Europe) from 2016 to 2022 were prospectively collected. Renal artery orientation was defined as hostile in case of upward (type B) or downward + upward (type D) orientation. Hostile RAs accommodated by BEVAR and combination of SE + BE stent grafts were retrospectively evaluated. Intra-operative RA related complications, technical success, and branch occlusions were assessed as early outcomes. Primary and secondary RA patency, freedom from RA related re-interventions, and freedom from RA instability were assessed during follow up. Of 584 TAAAs managed by F/B-EVAR, 83 patients (14.2%) had 125 hostile RAs (type B, 45.6%; type D, 54.4%) managed by BEVAR with hybrid SE + BE stent grafts. Intra-operative complications occurred in three RAs (2.4%), including two dissections and one disconnection, all successfully managed with additional stent. Technical success was achieved in all cases, with no RA occlusions at 30 days. The median follow up was 21 (interquartile range 4, 38) months. Estimated three year RA primary patency was 97 ± 2%. Re-interventions were performed in five RAs (4.0%), including two RA branch embolisations for bleeding, two catheter thrombectomies with stent relining (bilateral occlusion in one patient), and one revision of type Ic endoleak. Freedom from RA related re-interventions and RA instability was 95 ± 2% and 91 ± 3% at three years, respectively. Renal artery secondary patency was 99 ± 1% at three years. In hostile RA anatomies, a combination of distal SE and proximal BE stent grafts as bridging stenting in BEVAR is safe and effective, with low rates of occlusion, re-interventions, and branch instability at midterm follow up.

Intravascular lithotripsy in carotid disease.

Transcarotid artery revascularization (TCAR) is a hybrid approach with neuroprotective flow reversal for treating carotid stenosis. Providers are increasingly choosing it for patients, especially those at high risk for carotid endarterectomy (CEA). However, TCAR's efficacy is limited by calcific atherosclerosis, which can hinder stent expansion and increase the risk of perioperative embolization. Intravascular lithotripsy (IVL) is introduced as a promising solution to this issue. Initially developed for coronary and peripheral vascular diseases, IVL uses acoustic pressure waves to fracture calcific plaque, enabling better stent deployment. This work details the procedural steps for IVL in conjunction with TCAR, emphasizing its potential benefits and the adjustments needed due to the off-label use of currently available lithotripsy balloons. While IVL shows promise in addressing calcific atherosclerosis in carotid interventions, further research and development of carotid-specific devices are necessary. There is also the need for additional data on the safety and efficacy of this approach before it can be widely adopted.

TCT-413 Predictors of Stent Expansion in Subintimal Stenting for Chronic Total Occlusion: A Scoring System Based on IVUS Findings

TCT-413 Predictors of Stent Expansion in Subintimal Stenting for Chronic Total Occlusion: A Scoring System Based on IVUS Findings

TCT-390 Characteristics Associated With Optimal Stent Expansion in Patients With Calcified Lesions Receiving Rotational Atherectomy With or Without Cutting Balloon: A Secondary Analysis From the ROTA-CUT Randomized Trial

TCT-390 Characteristics Associated With Optimal Stent Expansion in Patients With Calcified Lesions Receiving Rotational Atherectomy With or Without Cutting Balloon: A Secondary Analysis From the ROTA-CUT Randomized Trial

Optimization stages of transjugular intrahepatic portosystemic shunt technique as a treatment method for portal hypertension complications

Aim. To describe the milestones to optimize of the technique of transjugular intrahepatic portosystemic shunt.Materials and methods. The PubMed and Embase databases, the Web of Science platform, the Google Scholar retrieval system, the Cochrane Database of Systematic Reviews, the eLIBRARY.RU scientific electronic library, and the reference lists were used to search for articles. Articles corresponding to the aim of the review were selected for 1969-2023. The inclusion criteria were limited to technical solutions related to optimize of the technique of transjugular intrahepatic portosystemic shunt.Results. Innovative ideas, subsequent experimental studies and preliminary experience in liver cirrhosis patients contributed to the introduction of transjugular intrahepatic portosystemic shunt into clinical practice. At the moment, the main achievement to optimize of the technique of transjugular intrahepatic portosystemic shunt is progress in the qualitative characteristics of stents. The transition from bare metal stents to expandable polytetrafluoroethylene-covered stent graft made it possible to largely prevent shunt dysfunction. However, the issue of its optimal diameter, contributing to an effective reduction of portal pressure without the risk of developing hepatic encephalopathy, which is one of the most common complications of transjugular intrahepatic portosystemic shunt, remains relevant.Conclusion. Further to optimize of the technique of transjugular intrahepatic portosystemic shunt, as well as careful selection of patients based on cognitive indicators, nutritional status and assessment of liver function will reduce the incidence of hepatic encephalopathy and improve treatment results.

Deep-learning-driven optical coherence tomography analysis for cardiovascular outcome prediction in patients with acute coronary syndrome.

Optical coherence tomography (OCT) can identify high-risk plaques indicative of worsening prognosis in patients with acute coronary syndrome (ACS). However, manual OCT analysis has several limitations. In this study, we aim to construct a deep-learning model capable of automatically predicting ACS prognosis from patient OCT images following percutaneous coronary intervention (PCI). Post-PCI OCT images from 418 patients with ACS were input into a deep-learning model comprising a convolutional neural network (CNN) and transformer. The primary endpoint was target vessel failure (TVF). Model performances were evaluated using Harrell's C-index and compared against conventional models based on human observation of quantitative (minimum lumen area, minimum stent area, average reference lumen area, stent expansion ratio, and lesion length) and qualitative (irregular protrusion, stent thrombus, malapposition, major stent edge dissection, and thin-cap fibroatheroma) factors. GradCAM activation maps were created after extracting attention layers by using the transformer architecture. A total of 60 patients experienced TVF during follow-up (median 961 days). The C-index for predicting TVF was 0.796 in the deep-learning model, which was significantly higher than that of the conventional model comprising only quantitative factors (C-index: 0.640) and comparable to that of the conventional model, including both quantitative and qualitative factors (C-index: 0.789). GradCAM heat maps revealed high activation corresponding to well-known high-risk OCT features. The CNN and transformer-based deep-learning model enabled fully automatic prognostic prediction in patients with ACS, with a predictive ability comparable to a conventional survival model using manual human analysis. The study was registered in the University Hospital Medical Information Network Clinical Trial Registry (UMIN000049237).

The Role of Intravascular Ultrasound in the Evaluation and Treatment of Free-Floating Stent Struts Following Inadequate Ostial Circumflex Stenting: A Case Report

Introduction: Excessive stent strut protrusion in the distal left main (LM) from either the left anterior descending (LAD) or circumflex (Cx) artery following inadequate ostial stenting may complicate any later procedure involving the left coronary artery. In such case scenarios, intravascular ultrasound (IVUS) guidance provides accurate assessment of the ostial stent position and may facilitate subsequent management strategies and treatment. Case summary: We present a complex percutaneous coronary intervention (PCI) of LM bifurcation in a 49-year-old man following inadequate ostial Cx stenting that resulted in excessive stent protrusion in the distal LM segment, accompanied by a subsequent short 80–90% ostial LAD stenosis. Initially, IVUS was performed to confirm “floating struts” from a previous Cx ostial stenting and to ensure complete intraluminal placement of the wire within the stent leading to the Cx, precluding any side passage through the stent struts. Then, a second wire was inserted into the LAD through the most distal stent strut under live IVUS guidance. Further PCI was completed according to the principles of the double kissing mini-culotte technique. Final IVUS runs confirmed correct stent apposition and expansion in the LM, LAD and Cx segments. Conclusions: In cases involving the treatment of “free-floating” struts in the distal LM artery, intravascular imaging is essential to ensure optimal PCI outcomes.

Development of colonic stent simulator using three-dimensional printing technique: a simulator development study in Korea.

Colonic stenting plays a vital role in the management of acute malignant colonic obstruction. The increasing use of self-expandable metal stents (SEMS) and the diverse challenges posed by colonic obstruction at various locations underscore the importance of effective training for colonic stent placement. All the components of the simulator were manufactured using silicone molding techniques in conjunction with three-dimensional (3D) printing. 3D images sourced from computed tomography scans and colonoscopy images were converted into a stereolithography format. Acrylonitrile butadiene styrene copolymers have been used in fused deposition modeling to produce moldings. The simulator replicated the large intestine from the rectum to the cecum, mimicking the texture and shape of the human colon. It enables training for colonoscopy insertion, cecum intubation, loop reduction, and stenting within stenotic areas. Interchangeable stenotic modules for four sites (rectum, sigmoid colon, descending colon, and ascending colon) were easily assembled for training. These modules integrate tumor contours and blood vessel structures with a translucent center, allowing real-time visualization during stenting. Successful and repeatable demonstrations of stent insertion and expansion using the reusable SEMS were consistently achieved. This innovative simulator offers a secure colonic stenting practice across various locations, potentially enhancing clinical outcomes by improving operator proficiency during actual procedures.

Elucidating the hemodynamic impact of residual stenosis post-carotid artery stenting: A numerical study.

Residual stenosis (RS) and hemodynamics demonstrate a significant correlation with postoperative in-stent restenosis/thrombosis following carotid artery stenting (CAS). This study endeavors to elucidate the potential associations between RS and adverse postoperative hemodynamic factors. This study utilized 46 patient-specific carotid artery models post-stenting, which were categorized into two groups based on the presence of RS: the normal group (N, n=23) and the RS group (RS, n=23). A comparative analysis was conducted to evaluate the discrepancies in geometry and adverse hemodynamic parameters, alongside investigating the potential correlation between hemodynamic and geometric parameters. The results reveal that a higher reflux flow volume is discernible in the RS group during low-velocity phases of the cardiac cycle, concomitant with an augmented extent of areas exposed to oscillatory shear stress and extended particle residence time. Moreover, the adverse hemodynamic parameters exhibit a positive correlation with the degree of stent expansion, stent length in the common carotid artery (CCA), and the distal slope of the RS. The distal slope and tortuosity of RS significantly influence the development of adverse hemodynamic conditions post-stenting, exacerbating the hemodynamic environment near the stenosis. Interestingly, while an extended stent length in the internal carotid artery (ICA) region improves hemodynamics by reducing flow disturbance, a longer stent in the CCA significantly worsens these conditions. Hence, it is prudent to analyze the characteristics of the local lesion regions to optimize the strategy for stent implantation.

Pulmonary Artery Endograft Implantation Using a Parallel Stent Grafting Technique to Enable the Treatment of a Bronchial Anastomosis Complication After Lung Transplantation.

Bronchial stenosis associated with bronchial anastomosis dehiscence after lung transplantation is a catastrophic complication following lung transplantation with a paucity of therapeutic solutions. To describe an adaptation of the parallel stent grafting technique in the pulmonary arterial territory to treat this challenging situation. This is a case report of a 52-year-old patient who presented bronchus stenosis and bronchial anastomosis dehiscence after lung transplantion. Bronchial stenting and lung retransplantation were contraindicated. Therefore, an endovascular approach using pulmonary artery endograft placement to prevent bleeding during repeated right bronchial balloon dilation was propposed. The technique consists of the deployment of an aortic extender endoprosthesis in the right main pulmonary artery and a balloon expandable stent in the upper lobe pulmonary artery (using a parallel graft configuration) through the common femoral and right internal jugular veins, respectively. Intraoperative transesophageal echocardiogram and one-lung ventilatory ventilation are needed. The patient underwent a new bronchoscopy 16 days after the procedure, that showed epithelization at the previous eroded zone, enabling bronchocopic balloon dialtion to be safely performed. A post-operative contrast-enhanced CT scan revealed an adequate positioning of the stent grafts. Despite all eforts, the patient succumbed to ventilator associated pneumonia on postoperative day 108. The technique's advantages include its feasibility even in situations in which other techniques may be contraindicated and its potential use in emergencies. Its limitations include the need for experienced interventionists to perform it, and the potential risk of acute tricuspid regurgitation. This study illustrates the early feasibility of the parallel stent grafting technique applied to the pulmonary artery territory. However, it's safety profile regarding infectious risk was not demontrated.

Safety, efficacy, and optical coherence tomography insights into intravascular lithotripsy for the modification of non-eruptive calcified nodules: A prospective observational study.

Non-eruptive calcium nodules (CNs) are commonly seen in heavily calcified coronary artery disease. They are the most difficult subset for modification, and may result in stent damage, malapposition and under-expansion. There are only limited options available for non-eruptive CN modification. Intravascular lithotripsy (IVL) is being explored as a potentially safe and effective modality in these lesions. This study aimed to investigate the safety and efficacy of the use of IVL for the modification of non-eruptive CNs. The study also explored the OCT features of calcium nodule modification by IVL. This is a single-center, prospective, observational study in which patients with angiographic heavy calcification and non-eruptive CN on OCT and undergoing PCI were enrolled. The primary safety endpoint was freedom from perforation, no-reflow/slow flow, flow-limiting dissection after IVL therapy, and major adverse cardiac events (MACE) during hospitalization and at 30 days. MACE was defined as a composite of cardiac death, myocardial infarction (MI), and ischemia-driven target lesion revascularization (TLR). The primary efficacy endpoint was procedural success, defined as residual diameter stenosis of <30% on angiography and stent expansion of more than 80% as assessed by OCT. A total of 21 patients with 54 non-eruptive CNs undergoing PCI were prospectively enrolled in the study. Before IVL, OCT revealed a mean calcium score of 3.7 ± 0.5 and a mean MLA at CN of 3.9 ± 2.1 mm2. Following IVL, OCT revealed calcium fractures in 40 out of 54 (74.1%) CNs with an average of 1.05 ± 0.72 fractures per CN. Fractures were predominantly observed at the base of the CN (80%). Post IVL, the mean MLA at CN increased to 4.9 ± 2.3 mm2. After PCI, the mean MSA at the CN was 7.9 ± 2.5 mm2. Optimal stent expansion (stent expansion >80%) at the CN was achieved in 85.71% of patients. All patients remained free from MACE during hospitalization and at the 30-day follow-up. At 1-year follow-up, all-cause death had occurred in 3 (14.3%) patients. This single-arm study demonstrated the safety, efficacy, and utility of the IVL in a subset of patients with non-eruptive calcified nodules. In this study, minimal procedural complications, excellent lesion modifications, and favorable 30-day and 1-year outcomes were observed.