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Significant progress has been made in both valves and delivery systems (DSs) for transcatheter aortic valve replacement (TAVR) procedures. We aimed to present one-year real-life data regarding TAVR procedures using Portico transcatheter heart valves (THVs) with new-generation, low-profile FlexNav DSs. This retrospective, single-center study enrolled 169 consecutive patients (mean age: 75.8 years, 68% females) with severe aortic stenosis undergoing TAVR with Portico THVs and FlexNav DSs between 2020 and 2021. We evaluated safety and efficacy outcomes, following the VARC-3 consensus, periprocedurally and at 30 days and 1 year. Procedural success was observed in 95.9% of cases, and no procedural mortality occurred. At 30 days, the rates of all-cause mortality, cardiovascular mortality, and neurological events were 4.7%, 3.6%, and 3.0%, respectively. Additionally, major vascular complications, acute kidney injury, and bleeding were recorded at rates of 11.2%, 14.8%, and 7.7%, respectively. The 1-year data showed all-cause mortality, cardiovascular mortality, and neurological event rates of 10.7%, 8.3%, and 7.7%, respectively. The moderate paravalvular leak and permanent pacemaker rates at 1 year were 2.6% and 12.2%, respectively. This real-life data provided evidence of positive outcomes and high technical success with Portico THVs and FlexNav DSs. Furthermore, we found low rates of mortality and neurological events, with satisfactory hemodynamic and functional results. [ABSTRACT FROM AUTHOR]

The shape memory properties (SMP) of long‐chain branched poly(lactic acid) (b‐PLA) vascular stent prepared through 3D‐printed technologies are studied by comparison with PLA. SMP is expected to endow vascular stent smart properties of self‐expanding stent, which could self‐expand and support the stenosis after reaching the lesion. The shape recovery rate of the b‐PLA samples at 60°C reaches to 93%, which is much higher than that of the PLA samples with 26%. The two‐cycle deformation‐recovery test of dynamic mechanical analysis (DMA) shows that the shape recovery rate of b‐PLA samples at 60°C reaches 98% in the first and second cycle, suggesting the good SMP. Meanwhile, the 3D‐printed b‐PLA vascular stent could recover to initial shape within 22 s, while the PLA vascular stent could not recover to initial shape after shape deformation at 60°C. Furthermore, Two‐dimensional wide‐angle X‐ray diffraction analysis (2D‐WXRD) diffraction results confirm that both PLA and b‐PLA samples exhibit two bright diffraction spots of (200)/(100) plane, and 2D‐SAXS scattering patterns changed from uniform scattering rings to the spindle‐shaped pattern after shape deformation. After shape recovery at 60°C, the 2D‐WXRD diffraction and two‐dimensional small‐angle X‐ray scattering analysis (2D‐SAXS) scattering patterns of the PLA samples remain no change, while b‐PLA samples recover to initial patterns and exhibit diffuse diffraction rings and uniform scattering rings, respectively, long period (Lac) decrease and lamellae thickness (Lc) maintain constant. The above results verify the excellent SMP of b‐PLA vascular stent as well as self‐expandable properties, which mainly ascribing to the combined action of branched entanglement points and lamellae as stationary phase. Besides, cell counting kit‐8 (CCK‐8) assays, cell live/dead staining and cell nuclei/cytoskeleton staining prove the good cell compatibility of b‐PLA stent before and after SMP. [ABSTRACT FROM AUTHOR]

Objective: Our 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. Methods: The 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. Results: All 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. Conclusions: The 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. : Clinical Relevance: The clinical relevance of our study titled ''Evaluation of Safety and Performance of a New Prototype Self-Expandable Nitinol Stent in an Ovine Model'' lies in its potential to advance the field of venous intervention. Stent implantation is a common procedure used to treat deep venous obstruction, and the use of self-expandable nitinol stents has been shown to be effective in improving the patency rates. However, the safety and efficacy of new stent prototypes must be evaluated thoroughly before they can be used in clinical practice. Our study contributes to the evaluation of a new prototype self-expandable nitinol stent by demonstrating its excellent mechanical properties, biocompatibility, and histopathological response in an ovine model. The results of our study may provide valuable insight for researchers and clinicians in developing and implementing new stent technologies, ultimately improving patient outcomes in the treatment of chronic venous obstruction.

Transcatheter aortic valve replacement (TAVR) is a safe and effective treatment option for patients with severe aortic stenosis at intermediate or high surgical risk. Results after TAVR in low-risk patients are very encouraging at midterm follow-up, whereas limited long-term (≥3 year) data are available in this subset of patients. This meta-analysis aims to compare the long-term follow-up after TAVR versus surgical aortic valve replacement (SAVR) in low-risk patients. We searched databases up to July 7, 2024 for randomized clinical trials comparing TAVR versus SAVR in low-risk patients (defined as Society of Thoracic Surgeons Predicted Risk of Mortality score <4%) (PROSPERO ID: CRD42023480495). Primary outcome analyzed was all-cause death at a minimum of 3 years of follow-up. The secondary outcomes were cardiovascular death, disabling stroke, myocardial infarction, aortic valve reintervention, endocarditis, new-onset atrial fibrillation, permanent pacemaker implantation, and bioprosthetic valve failure. A total of 3 randomized clinical trials with 2,644 patients (TAVR n = 1,371 patients; SAVR n = 1,273 patients) were included. The follow-up time was 6 ± 2.9 years. TAVR resulted noninferior to SAVR for all-cause death (risk ratio [RR] 0.99, 95% confidence interval [CI] 0.84 to 1.17, p = 0.89, I 2 = 28%), cardiovascular death (RR 0.94, 95% CI 0.76 to 1.15, p = 0.54, I 2 = 0%), myocardial infarction (RR 1.06, 95% CI 0.71 to 1.57, p = 0.79, I 2 = 61%), aortic valve reintervention, endocarditis, and bioprosthetic valve failure. New-onset atrial fibrillation was more common in the SAVR group, whereas permanent pacemaker implantation was more common in the TAVR group. In conclusion, our meta-analysis showed that TAVR is associated with similar long-term outcomes compared with SAVR in selected low-risk patients., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Treatment of severely calcified aortic valve stenosis is associated with a higher rate of paravalvular leakage (PVL) and permanent pacemaker implantation (PPI). We hypothesized that the self-expanding transcatheter heart valve (THV) prostheses Evolut Pro (EPro) is comparable to the balloon-expandable Sapien 3 (S3) regarding hemodynamics, PPI, and clinical outcome in these patients. Methods: From 2014 to 2019, all patients with very severe calcification of the aortic valve who received an EPro or an S3 THV were included. Propensity score matching was utilized to create two groups of 170 patients. Results: At discharge, there was significant difference in transvalvular gradients (EPro vs. S3) (dPmean 8.1 vs. 11.1 mmHg, p ≤ 0.001) and indexed effective orifice area (EOAi) (1.1 vs. 0.9, p ≤ 0.001), as well as predicted EOAi (1 vs. 0.9, p ≤ 0.001). Moderate patient prosthesis mismatch (PPM) was significantly lower in the EPro group (17.7% vs. 38%, p ≤ 0.001), as well as severe PPM (2.9% vs. 8.8%, p = 0.03). PPI and the PVL rate as well as stroke, bleeding, vascular complication, and 30-day mortality were comparable. Conclusions: In patients with severely calcified aortic valves, both THVs performed similarly in terms of 30-day mortality, PPI rate, and PVL occurrence. However, patient prothesis mismatch was observed more often in the S3 group, which might be due to the intra-annular design. [ABSTRACT FROM AUTHOR]

Infected walled-off pancreatic necrosis (WOPN) is a severe complication of acute pancreatitis. Surgery in these critically ill patients can be associated with increased morbidity and mortality. Hence, minimally invasive therapies have emerged as an alternative to surgery. Herein, we report a case of severe acute pancreatitis with WOPN which was treated percutaneously with a flexible endoscope through an esophageal self-expanding metal stent using a total retroperitoneal approach. Percutaneous direct endoscopic necrosectomy (p-DEN) using the retroperitoneal route improved the patient’s parameters dramatically with resolution of sepsis without the need for surgery. p-DEN using a flexible endoscope passed through a large bore metal stent shows promise in selected patients with WOPN and can be used in patients who are not ideal candidates for transmural or surgical drainage.

Objectives: Valve oversizing has been associated with reduced paravalvular leaks (PVL) and valve migration risk. However, no optimal cut-off oversizing value has been defined for the Evolut system (Medtronic). The aim of this study was to assess the relationship between the degree of oversizing and moderate-to-severe PVL and determine the optimal oversizing cut-off value., Methods: We conducted a multicenter study that included 740 consecutive patients with multidetector computed tomography (CT) data. Valve size was selected according to manufacturer recommendations, with oversizing ranging from 10% to 30%. The primary endpoint was moderate-to-severe PVL., Results: The median age was 84 years (79-87 years), with 58.4% women, and a median EuroSCORE II of 4.1% (2.4-7.3%). Moderate-to-severe PVL was observed in 7.0% of the patients. An inverse relationship was found between oversizing and both PVL (11.3%, 8.6%, 5.4%, and 2.7% for quartiles Q1 to Q4; P = .007) and the need for post-dilation (P = .016). The multivariable analysis showed an association between oversizing and PVL (OR: 0.915 for each 1%-increase, P = .002). The optimal oversizing cut-off value to predict PVL was 20%, and PVL was significantly higher in patients with oversizing less than 20% (10.5% vs.4.2%, P less than .001). There were no differences in major clinical events according to the degree of oversizing, and a higher oversizing did not translate into an increased risk of permanent pacemaker (18.4% vs18.3%, P = .976)., Conclusions: In TAVR with the Evolut valve, a higher oversizing was associated with lower rates of moderate-to-severe PVL and a lower need for post-dilation, with no negative impact on procedural and early clinical outcomes. A 20% oversizing threshold could be suggested to reduce PVLs. Further prospective studies are warranted to validate optimal oversizing for this valve system.

Background: The consequence of valve malposition (VM) during transcatheter aortic valve replacement (TAVR) can be severe, but the determinants of VM with self-expandable TAVR have not been thoroughly evaluated. We aimed to investigate the anatomical predictors of VM during self-expandable TAVR.Methods: In this multicenter retrospective study, TAVR was performed using the Venus A-Valve. The baseline, computed tomography, and procedural characteristics along with clinical outcomes were collected. Multivariate logistic regression model and receiver operating characteristic (ROC) curve analyses were performed.Results: A total of 84 consecutive patients (23 with VM) were included. Stepwise regression showed that annulus perimeter/left ventricular outflow tract perimeter (AL ratio) and sinotubular junction (STJ) height were predictors of VM. The ROC curve indicated a moderate strength of AL ratio [area under the curve (AUC) 0.71, cutoff 0.96] and a weak strength of STJ height (AUC 0.69, cutoff 23.8 mm) to predict VM. The combination of both predictors revealed a higher predictive value of VM (AUC 0.77). In multivariate analysis, AL ratio

This study aimed to compare incidence of IE between BE and SE valves by performing a systematic review and meta-analysis of the literature. We comprehensively searched the databases of MEDLINE and EMBASE from inception to November 2019. Included studies were published observational studies that compared the risk of IE among patients undergoing TAVR employing BE versus SE valves, using the random-effects to calculate risk ratios and 95% confidence intervals (CIs).Ten cohort studies from April 2013 to November 2019 were included in this meta-analysis involving 13,478 subjects (6289 SE and 7189 BE types). Our study showed no statistical difference in IE rates between each type of valves (pooled OR 0.96, 95% CI: 0.68–1.35, p = 0.801 with I2 = 14.7%). There was no difference in IE rate between BE and SE valves following TAVR. Further studies are warranted to confirm our findings. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide Open in new tab Download slide OBJECTIVES Transcatheter pulmonary valve replacement has become a valid treatment option for right ventricular outflow tract diseases. However, some limitations occur in patients with wide, compliant right ventricular outflow tracts that might be amenable to treatment with self-expanding valved protheses. An experimental ovine study was designed to evaluate a novel dip-coated, low-profile trileaflet polycarbonate urethane (PCU) heart valve mounted into a self-expandable nitinol stent. METHODS The PCU valves were produced by a dip-coating technique, mounted in a conical-shaped nitinol stent and provided with a leaflet thickness of 100–150 µm. The valved stents were implanted percutaneously via transfemoral access in 6 consecutive sheep divided into 2 groups. Three animals were followed up for 1 month and the remainder, for 6 months. Angiographic measurements and transthoracic echocardiography were performed before and after implantation and at the end of the 1- or 6-month observation period, respectively. RESULTS Orthotopic positioning of the valve was achieved in all animals. All except 1 had competent valves during the follow-up period. The peak-to-peak gradient across the PCU valved stents was 4.6 ± 1.0 mmHg after 1 month and 4.4 ± 2.3 mmHg after 6 months of follow-up. Macroscopic and microscopic post-mortem evaluation indicated good morphological and structural results. There were no stent fractures, leaflet calcification or thrombus formation. CONCLUSIONS This study demonstrates successful transcatheter pulmonary valve replacement with a novel dip-coated valved nitinol stent. The trileaflet PCU prostheses indicated good functional and biocompatible properties after a 6-month observation period. [ABSTRACT FROM AUTHOR]

Background: Transcatheter aortic valve replacement (TAVR) is now indicated in patients with symptomatic aortic stenosis and low, moderate, and high surgical risk. There are multiple types of valves available in TAVR. SAPIEN 3, and Evolut R are two of the most commonly used valves.Methods: We conducted a systematic review and meta-analysis of all studies that compared SAPIEN 3 vs Evolut R in patients undergoing TAVR. The primary endpoint of this meta-analysis was 30-day mortality. Secondary outcomes included major of life-threatening bleeding, risk of stroke, need of permanent pacemaker implantation, and risk of moderate to severe paravalvular regurgitation (PVR).Results: We included a total of 9 studies. One study was a randomized clinical trial, five were prospective observational studies and three were retrospective. 30-day mortality rate was similar between SAPIEN 3 and Evolut R (odds ratio (OR) 1.19; 95% confidence interval (CI) 0.72 to 1.93; p = 0.47). The risk of major or life-threatening bleeding (OR of 0.83, 95% CI 0.50 to 1.39; p = 0.48), and the risk of stroke (OR of 0.82, 95% CI 0.38 to 1.78; p = 0.62) were also similar between the two types of valves. Compared to SAPIEN 3, Evolut R was associated with statistically significant risk of permanent pacemaker implantation (OR of 1.40, 95% CI 1.15 to 1.70; p = 0.0007), and moderate to severe PVR (OR of 2.56, 95% CI 1.14 to 5.74; p = 0.02).Conclusions: At 30 day follow up, both Evolut R and SAPIEN 3 shared similar risks of 30-day mortality, major or life-threatening bleeding, and stroke; however greater odds of pacemaker placement implantation and moderate to severe PVR were associated with Evolut R. [ABSTRACT FROM AUTHOR]

The objectives of the study were to evaluate the impact of aortic angulation (AA) on success of transcatheter aortic valve replacement (TAVR) with a new generation self-expandable prosthesis (Medtronic Evolut R®). Specific anatomical conditions, such as for example the presence of a horizontal aorta with elevated AA, have seemed to pose a significant challenge for the correct positioning and consequent functioning of self-expandable TAVR prostheses. We assessed 146 patients treated with Evolut R. AA was measured at computed tomography and two groups were identified using as cutoff the mean AA value. Acute outcomes were collected and compared. AA mean value was 49.6 ± 9.4° (AA ≥ 50°: 76 and AA < 50°: 70 patients). Risk profile (Logistic euroSCORE: AA ≥ 50°: 15.7; 75% IQR: 11.1–22.1 vs. AA < 50°: 14.7; 75% IQR: 10.7–24.0; p = 0.8) was equivalent. Perioperative results were similar: valve resheathing (AA ≥ 50°: 21.0% vs. AA < 50°: 24.2%; p = 0.6), recapturing (AA ≥ 50°: 19.7% vs. AA < 50°: 25.7%; p = 0.3), fluoroscopy time (AA ≥ 50°: 11.1 IQR: 8.6–17.0 min. vs. AA < 50°: 11.0 IQR: 8.0–15.7 min.; p = 0.9), and contrast agent use (AA ≥ 50°: 99.0 ± 41.8 ml. vs. AA < 50°: 104.2 ± 38.5 ml.; p = 0.4). At discharge, moderate paravalvular leak was present in 8/76 (10.5%) of the AA ≥ 50° and 6/70 (8.6%) of the AA < 50° (p = 0.7) patients. Severe paravalvular leak, implantation of a second valve, and/or conversion to surgery did not occur. Early safety (AA ≥ 50°: 7.8% vs. AA < 50°: 5.7%; p = 0.6) was similar in the two groups. AA did not affect procedural outcomes and valve performance of the Evolut R prosthesis. [ABSTRACT FROM AUTHOR]

Atherosclerosis is one of the major types of cardiovascular diseases. Stent deployment into the stenosed artery is the most common treatment for atherosclerosis. Two common stent models based on two different expansion principles are balloon-expandable and self-expandable stents. Depending on the modality of the expansion, the material used for these two stents varies. Despite the extensive progress made in the field of stent construction, plaque fragmentation and in-stent restenosis are two of the problems that still cause complications in stenting. Computational modeling and finite element method help us predict the damage effects to the artery and plaque in the stenting process. In this article, we simulate the insertion of two stents (the stainless steel stent and the shape memory alloy stent) in a diseased artery with real geometry. Results are compared to account for the effects of these stents on the artery, especially, the maximum stress in the plaque and arterial layers and surgically induced damage as the main cause of plaque fracture during the stent deployment and in-stent restenosis. It is found that arising from superelasticity, the shape memory alloy stent induces less damage to the artery. In addition, the stress created in the artery by the shape memory alloy stent is smaller. Therefore, the risk of plaque fragmentation and in-stent restenosis is reduced in shape memory alloy stents. [ABSTRACT FROM AUTHOR]

The JR guide catheter is preferred for operability; however, we should pay more attention to the guide catheter in the case of radial artery approach with severe vessel tortuosity especially in patients with hypertension or in older female patients. [ABSTRACT FROM AUTHOR]

Introduction: This article aims to evaluate the short-term and mid-term performance of a self-expanding covered stent (COVERA Plus, Bard Tempe, Arizona) during the treatment of Trans-Atlantic Inter-Society Consensus (TASC) C/D aortoiliac obstructive lesions involving the aortic bifurcation., Methods: A single-center retrospective review of all patients who underwent endovascular reconstruction of the aortoiliac bifurcation for obstructive disease, with the use of Covera, from January 2018 to March 2023. All patients received a postoperative CTA (computed tomography angiography) scan within 1 month from the intervention. Precision of deployment, stent conformation, and stent symmetry were evaluated at the arterial phase of the CTA. Early outcomes were technical success and freedom from open aortic reintervention and/or mortality. Late outcomes were primary and assisted primary patency rates and freedom from reintervention., Results: During the study period, 35 patients underwent primary endovascular treatment of obstructive lesions involving the aortic bifurcation with parallel COVERA stents. Aortoiliac lesions were classified as TASC-IIC in 23 (65.7%) patients and TASC D in 12 (34.2%). Median follow-up was 49 months (interquartile [IQR]: 18-60). Overall survival was 97.1% (95% confidence interval [CI]=91-100) at 60 months. During follow-up, there were one early stent stenosis, treated with an angioplasty and stent relining with an estimated primary patency at 60 months of 97.1% (95% CI=94-100) and a primary-assisted patency of 100%. Estimated freedom from all types of reinterventions at 60 months was 94.3% (95% CI=89-99.3)., Conclusions: The new self-expanding covered Bard COVERA Plus stent used for endovascular treatment of TASC C/D aorto iliac disease proved to be safe and feasible with high technical procedural success rates. Comparison with other types of stents is necessary to further assess the role of the COVERA Plus stent in aortic bifurcation repair., Clinical Impact: This study investigates the safety and feasibility of the new self-expanding covered Bard Covera Plus stent used for endovascular treatment of TASC C/D aorto iliac disease. The retrospective analysis of 35 patients highlights high technical success and primary patency rate at 60 months. The geometric analysis also helped to underline how this stent can be used precisely in particular conditions. These findings suggest the need for further research to compare COVERA with other types of stents in aortic bifurcation repair., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Interventional therapy of failing surgical mitral valve replacement and repair is an appealing option in patients who are not eligible for redo surgery. We herein report on the first-in-human use of a repositionable, self-expandable transcatheter heart valve with motorized delivery for a transapical mitral valve-in-ring procedure. After implantation, fluoroscopy showed no residual regurgitation and pressure measurements did not reveal any signs of left ventricular outflow tract obstruction. [ABSTRACT FROM AUTHOR]

Transcatheter aortic valve replacement (TAVR) becomes the leading therapeutic choice for severe aortic stenosis. There is a growing body of knowledge on long-term survival outcomes, but available data from real-world observational studies are scarce. An observational cohort study was conducted on 705 consecutive patients who underwent TAVR at Strasbourg University Hospital between February 2010 and June 2017. We observed the living status (dead or alive) for each study participants by March 2023. The primary end point was to evaluate the all-cause mortality rate beyond 5 years after TAVR, compare the survival outcomes according to valve type, and identify predictors of mortality. Of the 705 study participants, 91.8% of the TAVR procedures were performed through the common femoral artery and 60.6% were treated with a balloon-expandable valve. Over a mean study period of 5.4 ± 3 years, the all-cause mortality rate was 45.8%. No difference in survival outcomes according to valve type was observed (p = 0.449). All-cause mortality rate was associated with age ≥90 years (hazard ratio [HR] 1.625, 1.109 to 2.380, p = 0.013), female gender (HR 0.228, 0.176 to 0.294, p <0.001), diabetes mellitus (HR 1.356, 1.070 to 1.719, p = 0.012), post-TAVR stroke (HR = 2.867, 1.690 to 4.865, p <0.001), and post-TAVR acute kidney injury (HR 1.977, 1.445 to 2.703, p <0.001). In conclusion, the present real-world large tertiary center experience showed that more than half of patients who underwent TAVR are alive beyond 5 years from procedure's date. All-cause mortality is mainly determined by advanced age and co-morbid conditions, and valve type has no advantage on the survival outcomes., Competing Interests: Declaration of Competing Interest The authors have no competing interests to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction and Objectives: Ureteral stricture is a chronic condition that can result in the obstruction of urinary drainage from the affected renal unit, leading to loss of renal function. Treatment methods can be categorized into two main headings: endourological and reconstructive procedures. We aimed to investigate the efficacy and safety of the self-expandable Allium® ureteral stent, which has been used in the minimally invasive treatment of ureteral stenosis in recent years., Materials and Methods: Twenty patients who were applied Allium® ureteral stent between 2017 and 2021 included in the study. The demographic and clinical characteristics of the patients, the details of the treatments applied to the patients, the perioperative and postoperative complications, the treatments applied for the complications and the findings in the follow-up were recorded and evaluated prospectively., Results: Etiology included urolithiasis in 16 patients (80%), malignancy in 3 patients (15%), and a previous gynecological operation in 1 patient (5%). Stent obstruction was found to be the most common complication in 3 patients (15%). Stent migration was the second most common complication in 2 patients (10%). Our follow-up continues with 15 patients without stent-related complications and stent obstruction. The mean follow-up period was 28 ± 15.7 months., Conclusions: Allium ureteral stent is an effective and reliable method in the minimally invasive treatment of ureteral stricture with complications seen at acceptable rates and ease of treatment in the management of complications., (Copyright © 2023 AEU. Published by Elsevier España, S.L.U. All rights reserved.)

Objectives: We herein report a single-center experience with the Portico TAVI system. Main focus was set on outcomes in patients with impaired left ventricular (LV) function and predictors for permanent pacemaker (PPM) implantation.Methods: Between 05/2014 and 10/2017, 106 consecutive patients received TAVI using the Portico device. For comparison of patients with/without impaired LV function, and determination of multi-slice computed tomography and electrocardiogram correlates for PPM implantation subgroups were built (Subgroup I: LVEF ≥ 50%, n = 69, Subgroup II: LVEF < 50%, n = 37; Subgroup A: no PPM implantation, n = 89; Subgroup B: PPM implantation, n = 17). Data were retrospectively analyzed.Results: Device success was 95.3% (101/106) with resulting transvalvular peak/mean pressure gradients of 10.6 ± 5.6/5.4 ± 3.1 and PVL ≥ moderate in 5/106 patients (4.7%). 30-day mortality was 4.7% (5/106; subgroup I 3/69, 4.3%; subgroup II 2/37, 5.4%; p = 1.0). Regarding VARC-2 adjudicated clinical endpoints stroke (3/106, 2.8%; subgroups I/II: 2/69 vs. 1/37, p = 1.0) and acute kidney injury (9/106, 8.5%; subgroups I/II: 6/69 vs. 3/37, p = 1.0), no significant differences were found. Postprocedural PPM implantation occurred in 17.9% (19/106) of the patients. Logistic regression for PPM implantation demonstrated predictive character of left coronary cusp (LCC) calcium load in zone 1 (annular plane to coronary ostia) (p = 0.05, threshold 193 mm3) and total calcium load of zone 1 (p = 0.05, threshold 751.2 mm3).Conclusions: The Portico valve demonstrates a satisfying safety outcome, especially for patients with impaired LV function. Results of the CE-mark trial were confirmed, except for higher PPM rates. PPM rates are in accordance with other reports on this TAVI platform. [ABSTRACT FROM AUTHOR]

Objectives The aim of this study was to perform a comprehensive analysis of factors that affect procedural outcomes of transcatheter aortic valve replacement using the ACURATE neo prosthesis (Symetis/Boston, Ecublens, Switzerland). Background Predictors of procedural outcomes using the ACURATE neo prosthesis are poorly understood. Methods A total of 500 patients underwent transfemoral aortic valve replacement with the ACURATE neo prosthesis. Device landing zone calcification was stratified as severe, moderate, or mild. Anatomic and procedural predictors of second-degree or greater paravalvular leakage and permanent pacemaker implantation were assessed. Results Post-procedural second-degree or greater paravalvular leakage was more frequent with increasing device landing zone calcification (mild 0.8% vs. moderate 5.0% vs. severe 13.0%; p < 0.001), whereas permanent pacemaker implantation was independent of device landing zone calcification. More severe periannular calcification (odds ratio [OR]: 1.007; 95% confidence interval [CI]: 1.003 to 1.010; p < 0.001), less oversizing (OR: 0.867; 95% CI: 0.773 to 0.971; p = 0.014), the presence of annular plaque protrusions (OR: 2.756; 95% CI: 1.138 to 6.670; p = 0.025), and aortic movement of the delivery system after full deployment (OR: 5.593; 95% CI: 1.299 to 24.076; p = 0.02), and sinotubular junction height (OR: 1.156; 95% CI: 1.007 to 1.328; p = 0.04) independently predicted second-degree or greater paravalvular leakage. Predictors of permanent pacemaker implantation were pre-existing right bundle branch block (OR: 3.122; 95% CI: 1.261 to 7.731; p = 0.01) and more oversizing (OR: 1.111; 95% CI: 1.009 to 1.222; p = 0.03). Conclusions Successful transcatheter aortic valve replacement using the ACURATE neo device predominantly depends on careful patient selection with appropriate oversizing and taking into account the individual anatomy and calcium distribution of the aortic root. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The main goal of this study was to compare the occurrence of post-deployment leaflet injury between prostheses made of porcine and bovine pericardium. METHODS: Two types of prostheses, self-expandable prostheses with porcine pericardial leaflet on one side and balloon-expandable prostheses with bovine pericardial leaflet on the other side, were used. In each group, crimped prostheses were compared with control non-crimped prostheses. Following a 15-min period of crimping, prostheses were deployed, and their leaflets were removed and subjected to analyses. The analyses included determination of global and local hydraulic conductance of the leaflets, leaflet plasma insudation and microscopic analysis. The results were expressed as percentage (standard error of the mean) or median (interquartile range). RESULTS: A significant increase in the global hydraulic conductance was only observed in the crimped balloon-expandable prostheses: 20.1 (15.5–41.2) ml/h/m2/mmHg vs 12.3 (9.0–15.6) ml/h/m2/mmHg (P=0.021). Similarly, areas of marked staining (a marker of local hydraulic conductance) were only seen in the bovine pericardium balloon-expandable prostheses. The incidence of leaflet plasmatic insudation was increased in the crimped prostheses compared with the control prostheses. The microscopic study revealed a higher occurrence of traumatic lesions in the crimped prostheses in comparison with the control prostheses: 33.3 ± 21.1% vs 5.5 ± 5.5% (P = 0.039) and 44.4 ± 20.5% vs 5.5 ± 5.5% (P = 0.017) in the bovine and the porcine leaflets, respectively. CONCLUSIONS: Post-deployment leaflet injury occurred in both types of prostheses. However, alteration of the global and local hydraulic conductance was important in the bovine pericardium balloon-expandable prostheses. [ABSTRACT FROM AUTHOR]

Present investigation deals with, tacrolimus eluting, self-expandable, biodegradable stent fabricated by solvent casting method. The design was based on shape memory polymers, which possess the ability to memorize temporary shape that can substantially differ from their initial permanent shape. A set of biodegradable polymers blend was used such as poly-lactic acid (PLA) and poly-l-glycolic acid (PLGA) to study the shape memory effect of polymer. The prepared stent was assessed for various parameters like Scanning Electron Microscopy (SEM),In-vitroandEx vivoexpansion, Drug content,In-vitrodrug release, Haemocompatibility, Differential Scanning Calorimetry (DSC), Fourier Transform Infrared spectroscopy (FTIR), and Textural Characterization. [ABSTRACT FROM PUBLISHER]

To investigate the technical periprocedural and midterm outcomes of endovascular repairs with multibranched endovascular repair or iliac branch devices combined with a new self-expanding covered stent. The COvera in BRAnch registry is a physician-initiated, multicenter, ambispective, observational registry (ClinicalTrials.gov Identifier: NCT04598802) enrolling patients receiving a multibranched endovascular repair or iliac branch devices procedure mated with Bard Covera Plus (Tempe, AZ) covered stent, designed to evaluate the outcomes of the covered stent mated with patient-specific and off-the-shelf branched stent graft. Primary end points were technical success, branch instability, and freedom from aortic and branch-related reintervention within 30 days and at follow-up. Preoperative characteristics, comorbidities, and outcomes definitions were graded according to the Society for Vascular Surgery reporting standards. Two hundred eighty-four patients (76 years; range, 70-80 years; 79% males) in 24 centers were enrolled for a total of 708 target vessels treated. The covered stents were mated with an off-the-shelf graft in 556 vessels (79%) and a custom-made graft in 152 (21%). Three hundred seven adjunctive relining stents in 277 vessels (39%) were deployed, of which 116 (38%) were proximal, 66 (21%) intrastent, and 125 (41%) distal. Adjunctive relining stent placement was more frequent when landing in a vessel branch instead of the main trunk (59% vs 39%; P =.031), performing a percutaneous access (49% vs 35%; P <.001), using a stent with a diameter of 8 mm or greater (44% vs 36%; P =.032) and a length of 80 mm or greater (65% vs 55%; P =.005), when a post-dilatation was not performed (45% vs 29%; P <.001) and when an inner branch configuration was used (55% vs 35%; P <.001). Perioperative technical bridging success was 98%. Eight patients (3%) died in the perioperative period. Two deaths (1%) were associated with renal branch occlusion followed by acute kidney injury and paraplegia. Follow-up data were available for 638 vessels (90%) at a median of 32 months (Q1, Q3, 21, 46). Branch instability was reported in 1% of branches. Forty-six patients (17%) died during follow-up, nine (3%) of them owing to aortic-related causes. Primary patency rates at 1, 2, and 3 years were 99% (581/587), 99% (404/411), and 97% (272/279), respectively. Branch instability was associated with patient-specific devices (9% vs 4%; P =.014) and intrastent adjunctive stent placement (12% vs 2%; P =.003), especially when a bare metal balloon-expandable stent was used (25% vs 3%; P <.001). The use of this new self-expanding covered stent mated with branched endografts proved to be safe and feasible with high technical procedural success rates. Low rates of branch instability were observed at midterm follow-up. Comparative studies with other commercially available covered stents are warranted. [ABSTRACT FROM AUTHOR]

BackgroundAortic valve predilation with balloon aortic valvuloplasty (BAV) is recommended before transcatheter aortic valve implantation (TAVI), despite limited data around the requirement of this preprocedural step and the potential risks of embolization. This study aimed to investigate the trends in practice and associations of BAV on short‐term outcomes in the UK TAVI registry. Methods and ResultsEleven clinical endpoints were investigated, including 30‐day mortality, myocardial infarction, aortic regurgitation, valve dysfunction, and composite early safety. All endpoints were defined as per the VARC‐2 definitions. Odd ratios of each endpoint were estimated using logistic regression, with data analyzed in balloon‐ and self‐expandable valve subgroups. Propensity scores were calculated using patient demographics and procedural variables, which were included in the models of each endpoint to adjust for measured confounding. Between 2007 and 2014, 5887 patients met the study inclusion criteria, 1421 (24.1%) of whom had no BAV before TAVI valve deployment. We observed heterogeneity in the use of BAV nationally, both temporally and by center experience; rates of BAV in pre‐TAVI workup varied between 30% and 97% across TAVI centers. All endpoints were similar between treatment groups in SAPIEN (Edwards Lifesciences Inc., Irvine, CA) valve patients. After correction for multiple testing, none of the endpoints in CoreValve (Medtronic, Minneapolis, MN) patients were significantly different between patients with or without predilation. ConclusionsPerforming TAVI without predilation was not associated with adverse short‐term outcomes post procedure, especially when using a balloon‐expandable prosthesis. Randomized trials including different valve types are required to provide conclusive evidence regarding the utility of predilation before‐TAVI.

A 47-year-old woman with stage IV chronic kidney disease developed a fistula between common carotid artery (CCA) and internal jugular vein (IJV) during central catheterization of the right IJV. The patient was treated with a self-expandable graft stent, which achieved successful closure of the carotid-jugular fistula. As demonstrated in our case, self-expandable graft stents could be a feasible treatment option for CCA-IJV fistulas without additional interventional procedures such as balloon angioplasty. [ABSTRACT FROM AUTHOR]

A proper interpretation of the forces developed during stent crimping and deployment is of paramount importance for a better understanding of the requirements for successful heart valve replacement. The present study combines experimental and computational methods to assess the performance of a nitinol stent for tissue-engineered heart valve implantation. To validate the stent model, the mechanical response to parallel plate compression and radial crimping was evaluated experimentally. Finite element simulations showed good agreement with the experimental findings. The computational models were further used to determine the hoop force on the stent and radial force on a rigid tool during crimping and self-expansion. In addition, stent deployment against ovine and human pulmonary arteries was simulated to determine the hoop force on the stent-artery system and the equilibrium diameter for different degrees of oversizing. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to evaluate performance and tissue response to a self-expandable bioabsorbable vein stent-base cut from a tube with enhanced stiffness and strength in vitro and in vivo.Methods: A diamond-shaped stent-base was cut from a sequential biaxially strained poly(L-lactide) (PLLA) tube for optimized performance. The performance of the stent-base was evaluated in a finite element analysis model, and validation was attempted in vitro through a cyclic flat-plate compression and radial force measurement. The performance of the stent-base was tested in vivo using 3 sheep with 2 implants each for 2 and 3½ weeks, respectively.Results: In vitro the stent-base showed an elliptical deformation but no fractures. In vivo the stent-base showed adequate radial force and no migration. All implanted stent-bases showed multiple fractures not only at the predicted stress zones but at all connecting points. Fragments of the caudal stent-base stayed in the vein wall indicating sufficient tissue coverage to avoid embolization of the fractured stent pieces, whereas fragments from the cranial device remaining were few. Neointima formation was confirmed histologically at 2 and 3½ weeks.Conclusion: A bioabsorbable self-expandable stent-base made from PLLA for large veins seems feasible, but over time, the PLLA used in this study appears too stiff and lacks the sufficient flexibility to move with the vena cava, causing multiple fractures. [ABSTRACT FROM AUTHOR]

Objectives: This study analyzes neocommissural alignment and the clinical and hemodynamic outcomes after transaxillary and transcarotid implantation of the Acurate neo2 transcatheter heart valve., Methods: We performed a retrospective, single-center analysis of early outcomes after transaxillary and transcarotid implantation of the Acurate neo2 transcatheter heart valve. Primary outcomes were neocommisural alignment, in-hospital mortality, and valve hemodynamic performance. Commissural alignment between native and transcatheter heart valves was assessed by transesophageal echocardiogram before and after the procedure., Results: Between October 2021 and November 2022, 40 consecutive patients were treated with the Acurate neo2 through a transaxillary or transcarotid approach. Access was achieved via the left subclavian artery in 30 cases and the left common carotid artery in 10 cases, with a mean vessel diameter of 6.7 mm. Implants most commonly used were size M (37.5%), L (35%), and S (27.5%). On the basis of transesophageal echocardiogram analysis, there was no significant difference in mean commissural orientation between native (mean, 65.1°; SD, 41.3°) and neocommissures (mean, 64°; SD, 44.1°) ( P  = .661). Mean commissural orientation did not significantly differ between native and neocommissures ( P  = .661). Optimal alignment or mild commissural misalignment was achieved in 99.5% of cases. There were no cases of severe commissural misalignment. Postprocedural mean values for peak and mean gradients were 12.7 mm Hg and 5.2 mm Hg, respectively. There were 2 cases of moderate paravalvular leak and 4 cases of mild paravalvular leak., Conclusions: This patient-specific technique for transaxillary and transcarotid insertion of the Acurate neo2 delivery system prevents implantations with more than mild commissural misalignment and with a high device success rate., (© 2023 The Author(s).)

Objective: Our 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., Methods: The 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., Results: All 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., Conclusions: The 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., (© 2023 by the Society for Vascular Surgery. Published by Elsevier Inc.)

Background The use of a balloon-expandable transcatheter heart valve previously resulted in a greater rate of device success compared with a self-expandable transcatheter heart valve. Objectives The aim of this study was to evaluate clinical and echocardiographic outcome data at longer term follow-up. Methods The investigator-initiated trial randomized 241 high-risk patients with symptomatic severe aortic stenosis and anatomy suitable for treatment with both balloon- and self-expandable transcatheter heart valves to transfemoral transcatheter aortic valve replacement with either device. Patients were followed-up for 1 year, with assessment of clinical outcomes and echocardiographic evaluation of valve function. Results At 1 year, the rates of death of any cause (17.4% vs. 12.8%; relative risk [RR]: 1.35; 95% confidence interval [CI]: 0.73 to 2.50; p = 0.37) and of cardiovascular causes (12.4% vs. 9.4%; RR: 1.32; 95% CI: 0.63 to 2.75; p = 0.54) were not statistically significantly different in the balloon- and self-expandable groups, respectively. The frequencies of all strokes (9.1% vs. 3.4%; RR: 2.66; 95% CI: 0.87 to 8.12; p = 0.11) and repeat hospitalization for heart failure (7.4% vs. 12.8%; RR: 0.58; 95% CI: 0.26 to 1.27; p = 0.19) did not statistically significantly differ between the 2 groups. Elevated transvalvular gradients during follow-up were observed in 4 patients in the balloon-expandable group (3.4% vs. 0%; p = 0.12); all were resolved with anticoagulant therapy, suggesting a thrombotic etiology. More than mild paravalvular regurgitation was more frequent in the self-expandable group (1.1% vs. 12.1%; p = 0.005). Conclusions Despite the higher device success rate with the balloon-expandable valve, 1-year follow-up of patients in CHOICE (Randomized Comparison of Transcatheter Heart Valves in High Risk Patients With Severe Aortic Stenosis: Medtronic CoreValve Versus Edwards SAPIEN XT Trial), with limited statistical power, revealed clinical outcomes after transfemoral transcatheter aortic valve replacement with both balloon- and self-expandable prostheses that were not statistically significantly different. (A Comparison of Transcatheter Heart Valves in High Risk Patients With Severe Aortic Stenosis: The CHOICE Trial; NCT01645202 ) [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to describe the procedural and early outcomes of patients with mechanical mitral valve prosthesis (MVP) undergoing transcatheter aortic valve replacement (TAVR) with a novel self-expandable retrievable device., Background: TAVR in patients with prior MVP may have an increased risk of complications related to device positioning and interference between both prosthetic valves., Methods: An observational study was conducted, including eight patients with severe symptomatic aortic stenosis and prior mechanical MVP who underwent TAVR with the novel device Allegra TM (Biosensors). No transesophageal monitoring was used., Results: The mean age of the study population was 75 years. The mean distance between MVP and aortic annulus was 3.8 mm. Procedural success was achieved in all patients with no major intraprocedural, in-hospital, or follow-up complications., Conclusions: TAVR with Allegra TAVI system in patients with prior MVP offers good procedural and clinical outcomes., (© 2022 Wiley Periodicals LLC.)

Objectives: Advancements in the endoscopic management of walled-off necrosis using lumen apposing metal stents have improved outcomes over its surgical and percutaneous alternatives. The ideal procedural technique and timing of direct endoscopic necrosectomy (DEN) have yet to be clarified., Methods: From November 2015 to June 2021, a retrospective comparative cohort analysis was performed comparing clinical outcomes for patients undergoing immediate DEN (iDEN) versus delayed DEN (dDEN). Subgroups were identified based on the quantification of necrosis. Wilcoxon two-sample tests were used to compare continuous variables and Fisher's exact test was used to compare categorical variables., Results: A total of 80 patients underwent DEN for management of walled-off necrosis (iDEN = 43, dDEN = 37). Technical success was achieved in all patients. Clinical success was seen in 39 (91%) patients in the iDEN group and 34 (92%) in the dDEN group. Amongst iDEN patients, the mean number of necrosectomies was 2.5 (standard deviation [SD] 1.4) in comparison to 1.5 (SD 1.0) for dDEN ( p -value = 0.0011). The median index hospital length of stay was longer with iDEN than dDEN (7.5 days vs. 3.0 days respectively, p -value = 0.010). Subgroup analysis was performed based on the percentage of necrosis (<25% vs. >25% necrosis). iDEN was associated with more necrosectomies than dDEN regardless of the percentage of necrosis ( p = 0.017 and 0.0067, respectively)., Conclusion: Patients undergoing dDEN had a shorter index hospital stay and fewer necrosectomies than iDEN. The large diameter of lumen apposing metal stents permits adequate drainage allowing a less aggressive approach thereby improving clinical outcomes and avoiding unnecessary interventions., Competing Interests: None., (© 2022 The Authors. DEN Open published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)

Objectives. Transcatheter aortic valve implantation (TAVI) is currently expanding worldwide, however all available prostheses share some fundamental design drawbacks. We investigated the feasibility, safety and hemodynamic performance of the innovative transapical Acurate TA™ self-expandable device, which has the unique advantage of offering anatomically correct self-alignment within the aortic root. Design. Transapical TAVI was performed in six acute swine and six chronic sheep procedures, with follow-up of 7, 14, 21, 28, 60 and 90 days. TAVI was performed under TEE and angiographic guidance without rapid pacing. Results. A partial sternotomy approach was used to access the LV-apex. All valve implantations were performed as planned and all animals survived the implantation procedure. After deployment, no migration, embolization or coronary obstruction was observed during the observation period. Intraoperative TEE examination identified no signs of intravalvular leakage or valve dysfunction. Transvalvular mean pressure gradients were 5.4 ± 2.2 mmHg decreasing during follow-up (1.6 ± 0.8 mmHg, 1.8 ± 0.8 mmHg, 1.3 ± 0.2, 1.8 ± 0.7 mmHg, 1.6 ± 0.8 mmHg), with a slight increase atday 90 (4.0 ± 2.4 mmHg, P < 0.05). Macroscopic examination at necropsy showed correct anatomical positioning of the valve stent without any signs of structural valve deterioration. Conclusions. These first results of the innovative self-expandable transapical ACURATE TA™ device explore the feasibility and safety of anatomically correct off-pump implantation with optimal hemodynamic results. [ABSTRACT FROM AUTHOR]

Limited data exist regarding fully-covered, self-expandable metal stents (CSEMS) with anchoring fins for the management of malignant distal biliary strictures. The aim of this study is to evaluate their safety and patency. Over a period of 2 years, 70 patients (45 males, 66 ± 13 years) underwent endoscopic retrograde cholangiopancreatography (ERCP) with placement of a 10-mm (67 patients) or 8-mm diameter (3 patients) CSEMS for the palliation of distal malignant biliary obstruction (pancreatic [53] or other [17]). Data were collected prospectively for survival and stent patency; complications were evaluated retrospectively. After CSEMS placement, 17 patients proceeded to surgery, and 53 patients were deemed unresectable. Mean survival for non-surgical candidates was 180 days (range: 15-1091), and 170 days (range: 9-589) for patients who underwent surgical management. CSEMS were left in place and remained patent for a mean of 163 days (range: 15-1091) in non-surgical candidates, and a mean of 55 days (range: 5-126) in surgical candidates. Complications during placement included wire perforations (4) and proximal deployment requiring repositioning (4), one of which was complicated by a bile leak. Post-procedure complications were observed in 24 cases (34%) and included post-ERCP pancreatitis (8, with 2 of them severe), post-procedure pain (5, with 3 requiring admission), cholecystitis (3), stent occlusion (3), cholangitis (2), proximal migration (1), post-sphincterotomy bleeding (1), and sepsis leading to death (1). CSEMS appear to provide acceptable short-term patency rates; however, their limited long-term patency and high complication rate might limit their widespread use. Further long-term prospective data are required to confirm this observation. [ABSTRACT FROM AUTHOR]

We describe our experience in which a retrievable Enterprise stent was used as a temporary recanalization and embolectomy device in an acute middle cerebral artery (MCA) occlusion after urgent stenting for ipsilateral carotid artery stenosis. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate whether drug coating of the recently developed covered SENDAI stents—self‐expandable stents covered with segmented polyurethane (SPU) films—reduces neointimal thickening in animal model. FK506, which is one of the most effective immunosuppressants, was used. Bare stents; non‐coated, covered stents; and FK506‐coated, covered stents were placed bilaterally in the external iliac arteries of beagle dogs. After 1‐month observation period, angiography did not show significant stent‐induced stenosis. Histological evaluation revealed a completely endothelialized intravascular lumen and the absence of thrombus formation. The area of the intimal thickening induced by the FK506‐coated stents was significantly smaller than that induced by the non‐coated stents, whereas it was larger in the case of both the covered stents than that in the case of the bare stent. In conclusion, FK506 treatment of the self‐expandable, covered stents was confirmed to effectively inhibit intimal thickening, although the SPU film used for covering functioned as a drug carrier in addition to a scaffold for intimal formation. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2009 [ABSTRACT FROM AUTHOR]

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We newly developed self‐expandable covered stents by combining two of our original technologies. Of these, the first is the dip‐coating covering method that was developed previously for balloon‐expandable stents; the other is the newly developed self‐expandable Nitinol stents, namely, Sendai stents. The three types of covered stents with the expansion diameter of 4.5, 5.0, or 6.0 mm thus obtained had a laser‐processed microporous elastomeric cover film (pore diameter: 100 μm, interpore distance: 250 μm). Although the film was extremely thin (∼15 μm), the film could be expanded without causing any damage, the strut was completely embedded within the film, and the luminal surface of the film was smooth and flat. Mechanical properties such as ideal flexibility to follow the shapes of arteries were almost retained even after covering. As appropriate drugs, the blood‐contacting inner and tissue‐contacting outer surfaces of the film were differentially coated with argatroban for antithrombogenicity or FK506 for anti‐inflammation, respectively. The preliminary in vivo study indicated that the covered stents mounted in the delivery catheter were navigated and placed to appropriate position in the arteries, and permissible neointimal thickening after 1‐month implantation was observed similarly in noncovered stents. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007 [ABSTRACT FROM AUTHOR]

Abstract: This work reports, for the first time, the development of a fully biodegradable polymeric stent that can self-expand at body temperatures (∼37°C), using the concept of elastic memory. This self-expansion is necessary in fully polymeric stents, to overcome the problem of elastic recoil following balloon expansion in a body vessel. Bi-layered biodegradable stent prototypes were produced from poly-l-lactic acid (PLLA) and poly glycolic acid (PLGA) polymers. Elastic memory was imparted to the stents by temperature conditioning. The thickness and composition of each layer in the stents are critical parameters that affect the rate of self-expansion at 37°C, as well as the collapse strengths of the stents. The rate of self-expansion of the stents, as measured at 37°C, exhibits a maximum with layer thickness. The T g of the outer layer is another significant parameter that affects the overall rate of expansion. [Copyright &y& Elsevier]