Self-expanding Nitinol Stent Research Articles

A clinical case of acute intestinal obstruction as a result of dislocation of the esophageal self-expanding nitinol stent

INTRODUCTION: Covered esophageal self-expanding stents are often used to palliate dysphagia in patients with unresectable esophageal and gastric cardia cancer. Migration of an esophageal stent is a common occurrence in these patients. One of rare complications that can be caused by stent dislocation is intestinal obstruction. The article describes a case of intestinal obstruction in result of migration of a fully covered nitinol esophageal stent. Patient K., 53 years old, was admitted to hospital in a severe condition with complaints of vomiting, abdominal pain and stool retention that had persisted for four days. The patient refused esophagogastroduodenoscopy. A plain abdominal X-ray did not reveal any free gas. In the mesogastrium, numerous pneumatized loops of small intestine with horizontal fluid levels were identified. For life indications, the patient, after preoperative preparation was taken to the emergency operating room; resection of the terminal part of small intestine was performed with placement of an ileostomy and gastrostomy. Taking into account difficulties of diagnosis (refusal of esophagogastroduodenoscopy by the patient and low informative value of X-ray examination), severity of the patient’s condition (due to a malignant neoplasm and intestinal obstruction), anatomical peculiarities (location of the esophageal stent 30 cm from the ileocecal angle, which would complicate potential application of enteroenteroanastomosis), the chosen tactics was to refuse application of enteroenteroanastomosis and exteriorize ileostomy and gastrostomy. CONCLUSION: Acute intestinal obstruction is a threatening complication of migration of an esophageal stent. Patients with placed esophageal stents require careful monitoring, use of a sparing diet and additional methods of stent fixation, which will help reduce the frequency of stent migration and associated complications.

Post neck radiation cancer carotid pseudoaneurysm blowouts with Viabahn stent placement

Carotid Blowout Syndrome (CBS) is a critical and often fatal complication associated with head and neck malignancies. CBS is characterized by three stages: threatened, impending, and acute rupture/hemorrhage. The condition is notably linked with a history of radiotherapy for head and neck cancers, with an incidence of approximately 3-4% among those who have received such treatment. Historically, surgical management of CBS has involved open surgical ligation. However, advancements in endovascular techniques, including endovascular destructive procedures (e.g., coil embolization) and reconstructive procedures (e.g., carotid artery stenting), have become increasingly prevalent. This report presents two cases where a self-expandable PTFE-coated nitinol stent with a heparin coating (Viabahn; Gore and Associates) was utilized in the treatment of CBS.

Newly Designed, Self-Expanding Large-Bore Nitinol Stents for Symptomatic Central Venous Stenosis: Technical and Long-Term Clinical Outcome.

To retrospectively analyze the technical and long-term clinical outcome of angioplasty and stenting using the Venovo™ venous stent for the treatment of malignant and benign superior vena cava (SVC) occlusive disease. Consecutive patients treated with the Venovo™ venous stent for SVC occlusive disease were included. SVC obstruction symptoms were classified according to the Kishi score. The Wilcoxon signed-rank test was used for testing significance of changes. Technical success, defined as correct placement of the stent, completely covering and re-expanding the obstruction, between groups was tested using the Fisher exact test. Overall survival was calculated using the Kaplan-Meier method. Fifty-five patients underwent stent insertion for symptomatic benign (n = 13; 24%) or malignant (n = 42; 76%) SVC occlusive disease. A significant drop in Kishi score, mean 3.91 before versus mean 1.02 after the procedure (P < 0.0001), was observed. In one patient (1.8%), an additional balloon-expandable stent was needed to manage incomplete expansion of the nitinol stent. In one patient, a procedure-related lung embolic complication was noted. Early thrombotic occlusion of the stent occurred in one patient. Late symptomatic restenosis occurred in 3 patients. Overall primary stent patency and primary-assisted stent patency were 86% (95% CI 66-95) and97% (95% CI 83-100) at 1-year follow-up and 98% (95% CI 87-100), 98% (87-100) at 2-year follow-up, respectively. In this retrospective analysis, angioplasty and stent placement using the Venovo™ venous stent is safe and clinically effective for the treatment of both benign and malignant SVC occlusive disease. Reintervention for symptomatic restenosis is rare.

Static and dynamic behaviours of a self-expanding nitinol stent real contact area within a PTFE catheter: A multiscale approach

Current research on self-expanding super-elastic nitinol stents is mainly focused on designing geometries suited to the human venous and arterial systems. This study specifically considers a patented one-piece double cross-sectional stent designed to address venous stenosis affecting the vena cava, iliac veins, and their bifurcations. Before its placement within the vein, numerous tribological challenges arise as the stent slides along the guide-wire (so-called catheter). These are mainly connected to the lack of knowledge related to (i) its frictional behaviour and (ii) the level of contact pressure linked to the unknown real contact area between the compressed stent and the polytetrafluoroethylene (PTFE) catheter.This paper describes an original multi-scale approach, based on the Persson’s contact theory, that allows determination of (i) the contact pressure, (ii) the evolution of the real contact area, and (iii) the shear stresses at the interface during the stent sliding. A topographical optimization criterion will finally be provided, enabling control of both friction and stick–slip phenomena at the stent-catheter interface.

Evaluation of short and mid-term clinical outcomes in patients with aortic coarctation treated with self-expandable stents

The present study aimed to evaluate the outcomes of percutaneous treatment of aortic coarctation using self-expandable uncovered Nitinol stents. We conducted a retrospective clinical data review of all patients with aortic coarctation and treated with self-expandable uncovered Nitinol stents at our institution between 2009 and 2019. The gradient pressure across the coarctation site was measured using aortography. Follow-up echocardiography and computed tomography angiography were performed to assess possible stent complications. A total of 127 stents were successfully implanted in 125 patients (64.8% males) with a mean age of 35.36 ± 11.9 years. The gradient across the coarctation site decreased significantly from 67.48 ± 14.79 to 5.04 ± 3.01 mmHg (P < 0.001) after self-expandable stent implantation. Systolic blood pressure (SBP) decreased significantly from 175.53 ± 15.99 to 147.22 ± 12.83 mmHg (P < 0.001) after self-expandable stenting. There were no major technical or clinical complications, including balloon rupture, aneurysmal formation, infection, secondary stent migration, thrombosis, death during the procedure, and in-hospital mortality. On a mean follow-up of 48 ± 23.6 months (12–120 months), the gradient [from 59.43 ± 15.42 to 3.72 ± 1.38 mmHg (P < 0.001)] and SBP [from 175.53 ± 15.99 to 127.99 ± 7.82 mmHg (P < 0.001)] decreased significantly. There was no mortality, aneurysmal formation in the stent site, dislocation, or aortic re-stenosis requiring intervention during mid-term follow-up. Treatment of aortic coarctation using a self-expandable uncovered nitinol stent is safe and effective with promising mid-term outcomes.

Pivotal Evaluation of Novel Dedicated Venous Stent for Iliofemoral Venous Obstruction: A Prospective Cohort Study.

The purpose was to evaluate the clinical outcomes of a dedicated venous stent with the tripartite composite segments for the treatment of iliofemoral venous obstruction (IVO) in a mixed cohort of nonthrombotic iliac vein lesion (NIVL) and post-thrombotic syndrome (PTS) over a period of 12 months. The Grency Trial is a prospective, multicenter, single-arm, open-label, pivotal study, which was conducted at 18 large tertiary hospitals in China from August 2019 to October 2020. A total of 133 hospitalized patients were screened and 110 patients with clinical, etiology, anatomical, and pathophysiology clinical class (CEAP) clinical grade C>3 and iliac vein stenosis >50% or occlusion, including 72 patients with NIVL and 38 patients with PTS, were implanted with Grency venous stents. Primary endpoint was stent patency at 12 months follow-up, and secondary outcomes were technical success; improvement in venous clinical severity score (VCSS) at 3, 6, and 12 month follow-up; and rates of clinical adverse events. Among 110 patients who were implanted with Grency venous stents, 107 patients completed the 12 month follow-up. All 129 stents were successfully implanted in 110 limbs. Twelve-month primary patency rate was 94.39% [95% confidence interval [CI]=88.19%-97.91%] overall, and 100% [94.94%-100%] and 83.33% [67.19%-93.63%] in the NIVL and PTS subgroups, respectively. Venous clinical severity score after iliac vein stenting improved significantly up to 12 months follow-up. There were 3 early major adverse events (1 intracerebral hemorrhage and 2 stent thrombosis events related to anticoagulation therapy), and 7 late major adverse events (1 cardiovascular death, 1 intracranial hemorrhage with uncontrolled hypertension, and 5 in-stent restenosis cases without stent fractures or migration). The Grency venous stent system appeared excellent preliminary safe and effective for IVO treatment. Further large-scale studies with longer-term follow-up are needed to evaluate long-term patency and durability of stent. The design of venous stents for iliofemoral venous obstruction (IVO) must address engineering challenges distinct from those encountered in arterial stenting. The Grency venous stent, a nitinol self-expanding stent specifically tailored for IVO, features a composite structure designed to meet the stent requirements of various iliac vein segments. The Grency Trial is a prospective, multicenter, single-arm, open-label pivotal study aimed at evaluating the efficacy and safety of the Grency stent system. Following a 12-month follow-up period, the Grency venous stent system has demonstrated both safety and efficacy in treating iliofemoral venous outflow obstruction.

Compression Hemostasis in Refractory Esophageal Bleeding

RELEVANCE. Efficiency and safety of compression hemostasis with esophageal self-expanding nitinol stents Danis compared to the Sengstaken–Blakemore tube in the treatment program of refractory esophageal bleeding still remains a controversial issue. AIM OF THE STUDY. To conduct a comparative analysis of the effectiveness of Danis self-expanding compression hemostasis nitinol stent and the Sengstaken-Blakemore tube for variceal esophageal bleeding refractory to drug and endoscopic treatment. MATERIAL AND METHODS. The first comparison group included 44 patients, in whose complex treatment program tamponade with a Sengstaken-Blakemore tube was used to save lives. The second main group of the study consisted of 15 patients in whom compression hemostasis was performed using Danis self-expanding nitinol stent. Statistical processing was carried out using the Kolmogorov-Smirnov, Student, χ2 and Fisher exact tests. Differences were considered statistically significant at p ≤ 0.05. RESULTS. In the comparison group, complications occurred in 44 (100 %), in the main group complications were observed in 8 patients (53.3 %). Accordingly, reliable mechanical hemostasis was achieved in 33 (75.0 %) and 13 clinical observations (86.7 %); trophic changes in the esophageal mucosa were detected in 12 (27.2 %) and 8 patients (53.3 %). When assessing the function of external respiration, 5th and 2nd degrees of decrease in the ventilation capacity of the lungs, as well as 3rd and 1st degrees of decrease in the vital capacity of the lungs were established. The overall mortality was 56.8 % in the comparison group and 26.7 % in the main group. CONCLUSION. Self-expanding compression hemostasis nitinol stent Danis as a bridge to the choice of definitive therapy compared to tamponade with the Sengstaken–Blakemore tube is a promising alternative first-line treatment for patients with refractory esophageal bleeding. At the same time, it is necessary to conduct randomized controlled studies to confirm the safety and effectiveness of self-expanding nitinol stents.

A process chain study for manufacturing nitinol stents

Nitinol is a commonly used alloy for manufacturing medical devices (i.e., stents). This study examines the process chain for manufacturing nitinol stents, focusing on the effects of laser cutting, heat treatment, and electropolishing processes on the stent’s final surface roughness, strut thickness, weight, and recoil. The laser cutting’s experimental results showed an optimal surface roughness (Ra) under 1.20 μm at 65% and 95% spot overlap, corresponding to feed rates of 300 mm/min and 749 mm/min, respectively. Heat treatment experiments on expanded stent samples revealed the lowest recoil of 0.78 mm achieved at 550°C for 720 s for 0.2 mm strut thickness. Electropolishing using 18V for 20 s provided the greatest reduction in surface roughness (Ra and Rz), along with a decrease in the weight and wall thickness. The results highlight the importance of optimizing process parameters to obtain desired surface quality, shape setting, and dimensional characteristics for functional nitinol stents. The research provides insights into enhancing the manufacturing of self-expanding nitinol stents for improved clinical outcomes.

An in vivo investigation on the effects of stent implantation on hematological and hemorheological parameters.

Even though cardiovascular stenting is widely used for the treatment of coronary artery disease, information on how it can affect the hematological and hemorheological profile is scarce in the literature. Most of the work on this issue is based on theoretical or computational fluid dynamics models, lacking in-depth in vitro and in vivo experimental verification. This work investigates, in an in vivo setting, the effects of stenting and the implantation time-course on hematological and hemorheological parameters that could potentially compromise the device's functionality and longevity. Custom-made self-expanding nitinol stents were implanted in the common carotid artery of male CD1 mice. Whole blood samples were collected from control (non-stented) and stented animals at 5 and 10 weeks post-implantation. Hematological measurements and blood viscosity, red blood cell aggregation, and deformability were performed using standard techniques. Implant-induced changes were observed in some of the hematological and hemorheological indices. Blood viscosity seems to have been negatively affected by an increased hematocrit and reduced RBC deformability, at 10 weeks post-implantation, despite a slight decrease in RBC aggregation. Although the alterations observed may be the result of the peri-implant inflammatory response, the physiological consequences due to hemorheological changes need to be further investigated.

Randomized clinical trial to compare the efficacy of self-expanding bare metal nitinol stent and balloon angioplasty alone for below-the-knee lesions following successful balloon angioplasty: 1-year clinical outcomes.

This prospective, multicenter, randomized study aimed to compare the 1-year clinical outcomes after primary stenting with self-expanding bare metal nitinol stent (SENS) and plain old balloon angioplasty (POBA) in patients with critical limb ischemia (CLI) and below-the-knee (BTK) lesions. Overall, 119 patients with CLI and BTK lesions were randomized to POBA alone (POBA group, 61 patients) or primary stenting with SENS (stenting group, 58 patients) after achieving acceptable POBA results in target BTK lesions. Clinical outcomes including amputation and revascularization rates were prospectively compared for 1 year. After 1 year, similar incidence rates of individual clinical endpoints, including cardiac death (6.5% vs. 5.1%, p > 0.999), myocardial infarction (1.6% vs. 0.0%, p > 0.999), repeat revascularization (19.6% vs. 18.9%, p = 0.922), target lesion revascularization (13.1% vs. 17.2%, p = 0.530), and amputation (4.9% vs. 0.0%, p = 0.244), were observed. POBA appeared to have acceptable treatment outcomes compared with primary stenting with SENS after 1 year in CLI patients with BTK lesions undergoing percutaneous transluminal angioplasty (PTA).

Balloon-expandable cheatham-platinum stents versus self-expandable nitinol stents in coarctation of aorta: 3-year outcome of a randomized clinical trial

Abstract Introduction Although stenting showed early promising results in the treatment of patients with coarctation of aorta (CoA), its long-term benefit it is scarcely studied. Previously, we have shown, balloon-expandable stents (BES) and self-expandable (SES) stents were both effective and safe during 12-month follow up in the treatment of native CoA. Purpose To report the 3-year outcomes of BES versus SES stents in patients with native CoA. Methods Adult patients with de novo native CoA were randomized into Cheatham-platinum BES and uncovered nitinol SES groups in this parallel-group, open-label, blinded endpoint randomized clinical trial. All randomized patients were assigned to the 3-year structural follow up, consisted of clinical examination (including blood pressure measurement), exercise test for detecting masked hypertension, aortic CT angiography and transthoracic echocardiography. The 3-year incidence of recoarctation of aorta, thoracic aortic aneurysm formation, and residual hypertension were reported as the main long-term outcomes. Results Of the 92 patients initially randomized, 71 patients were participated in 3-year structural follow-up (Figure 1). Residual hypertension, defined as a persistent need for antihypertensive drugs at 3-year were significantly higher in BES (25 (71.4%) versus 17 (47.2%) patients (risk ratio (RR), 1.51, 95% confidence interval (CI), [1.00 to 2.26], p= 0.03) (Figure 2). Apart from five patients diagnosed with recoarctation during the first year of follow-up, no new cases of recoarctation were detected between 1 to 3-year follow up. Of note 2 of 3 patients with recorctation in the BES group, needed a second reintervention during the long-term follow up. Thoracic aortic aneurysm formation was not different in both stent types (4 (11.4%) versus 2 (5.6%) patients (RR, 2.06, 95% CI, [0.40 to 10.52], p= 0.37). Three-year median differences of ascending aorta and aortic arch were not different between the two groups. Conclusion Overall, both BES and SES were safe and effective in the long-term follow up. The rate of recoarctation was low even in the long-term follow up, which were safely reintervene. A hypothesis-generating difference were detected between two types of stents on residual hypertension which needs to be verified in larger studies.Baseline Characteristics and Study Flow3-year Outcomes

Coaxial Placement of Balloon-Expandable and Self-Expanding Stents: Impact on Crush Resistance and Luminal Recovery in a Benchtop Model

During endovascular interventions, coaxial deployment of stents may be required to preserve luminal gain. This study characterized in vitro the effect on crush resistance and postcompression recovery when 316L stainless steel balloon-expandable (BE) and laser-cut nitinol self-expanding (SE) venous stents were deployed coaxially. Various stent configurations were parallel-plate compressed from a fully expanded state to 50% diameter reduction (Criterion, Model 42; MTS, Eden Prairie, Minnesota) in a 37 °C ± 1 water bath. Coaxial deployments of SE stent inside BE stent and BE stent inside SE stent demonstrated higher crush resistances compared with each stent individually or their mathematical summation (analysis of variance P < .0001; pairwise comparison P < .01). The configuration of SE stent inside BE stent showed higher postcompression luminal recovery at 48.7% compared with that of BE stent inside SE stent at 27.5% (P = .0001). Coaxial deployment of SE stent inside BE stent may improve crush resistance and luminal recovery after compression in the appropriate clinical context.

Double-Barrel Nitinol Stent Placement for Iliocaval Reconstruction: The Effect of Deployment Sequence and Direction on Final Configuration

Double-barrel stent placement across the iliocaval confluence is commonly used for the treatment of chronic bilateral iliocaval occlusion. The difference in the deployment outcomes of synchronous parallel stent deployment versus asynchronous or antiparallel deployment and the underlying stent interactions are poorly understood. In this study, 3 strategies of double-barrel nitinol self-expanding stent deployment across the iliocaval confluence (synchronous parallel, asynchronous parallel, and synchronous antiparallel) were contrasted in vivo in 3 swine followed by assessment of the explanted stent construct. Synchronous parallel stent deployment achieved a desired double-barrel configuration. The asynchronous parallel and antiparallel deployment strategies both resulted in a crushed stent despite subsequent simultaneous balloon angioplasty. These animal model results suggested that in patients who undergo double-barrel iliocaval reconstruction, synchronous parallel stent deployment may provide the desired stent conformation and increase the chance for clinical success.

Treatment of Long Femoropopliteal Occlusive Lesions With Self-expanding Interwoven Nitinol Stent: 24 Month Outcomes of the STELLA-SUPERA-SIBERIA Register Trial.

The efficacy and safety of the Supera stent in superficial femoral artery (SFA) have been reported mostly in shorter lesions with relatively low proportion of occlusions. There are little data on the effectiveness of the Supera stent in long lesions. The aim of this study was to assess the clinical safety and efficiency of the Supera stent in the treatment of long femoropopliteal occlusive lesions (Trans-Atlantic Inter-Society Consensus [TASC] C/D) in patients with symptomatic peripheral artery disease. The STELLA-SUPERA-SIBERIA is a prospective, single-center, single-arm study. Patients with symptomatic (Rutherford stages 3-6) de novo and TASC C/D occlusive lesions of the femoropopliteal segment were treated with Supera stent. The primary endpoint was the 12 month rate of primary sustained clinical improvement (upward shift on the Rutherford classification to a one level without the need for repeated target lesion revascularization (TLR) in surviving patients without the need for unplanned amputation). Secondary endpoints were the 24 month of primary sustained clinical improvement, MALE, limb salvage, the primary patency, the secondary patency, 24 month MACE. Follow-up included clinical examination, duplex scan, and biplane x-ray up to 24 months. Between April 2019 and January 2020, 52 symptomatic patients with 55 long femoropopliteal occlusive lesions (52.7% TASC D lesions and 47.3% TASC C lesions) were treated. The mean target lesion length was 205±72 mm. All patients had total occlusions. The mean lesion length of the implanted Supera stents was 198±82 mm. At 12 and 24 months, the primary sustained clinical improvement rate was 80.2% and 63.6%, respectively. The Rutherford category assessment was significantly improved at 24 months compared with baseline (p=0.02). The primary patency rate at 12 and 24 months was 78.1% and 60.0%, respectively. At 12 and 24 months, freedom from TLR was 83.5% and 81.8%, respectively. There were no stent fractures at 24 months. Supera Stent implantation for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Head-to-head studies are mandatory to establish Supera Stent as an alternative tool to open surgery for long femoropopliteal lesions. Our study indicated, that using self-expanding interwoven nitinol stent for TASC C/D femoropopliteal lesions revascularization appears to be a safe and efficient implant given the complexity of the treated lesions. Although bypass grafting is recommended for prolonged femoropopliteal lesions, open surgery is more traumatic and is associated with greater risks than endovascular procedures. Our findings suggest that the use of interwoven nitinol stents can overcome the disadvantages of traditional stents in such cases, which may help to improve patients' outcomes and reduce the risk of adverse events.

Endovascular Stent Thrombectomy in Patients With Acute Lower Limb Arterial Thrombosis on the Background of COVID-19

AIM Analysis of the outcomes of endovascular stent thrombectomy in patients with acute arterial thrombosis of the lower extremities on the background of COVID-19.MATERIAL AND METHODS This retrospective study for the period from January 1, 2020 to March 1, 2022 included 34 patients with acute lower limb ischemia who were diagnosed with the novel coronavirus infection SARS-COV-2. Endovascular stent thrombectomy was performed according to the standard technique using a Destination 8F guiding sheath (Terumo), an Advantage 0.014`` guidewire (Terumo), and a Casper stent (Microvention, Terumo) as a stent retriever. In case of fragmentation of thrombotic masses in the guide sheath, manual aspiration of thrombi was performed using a standard 50,0 ml syringe. Self-expanding nitinol stents were implanted in 11 clinical cases.RESULTS Intraoperative bleeding from the puncture site of the artery developed in 14.7% of cases, which required additional manipulation to achieve hemostasis. Every tenth (11.8%) patient developed myocardial infarction, in 2.9% of cases — ischemic stroke. In the hospital postoperative period during the first hours after surgery, 26.5% of patients developed rethrombosis which required re-intervention. In 8.8% of cases, retrombectomy was unsuccessful, and limb amputation was performed. A fatal outcome occurred in 67.6% of cases, which was due to an increase in multiple organ failure and the development of sepsis.CONCLUSION Endovascular stent thrombectomy is characterized by a low risk of rethrombosis and amputation in the context of COVID-19.

Development of innovative system of universal stent graft for endovascular treatment of aneurysm and aortic displacement in various locations

This study presents the technology of developing a universal stent graft for endovascular treatment of aneurysms and aortic dissection of various localizations, without considering the vessel diameter. A self-expanding nitinol stent was used as the frame of the main trunk of the stent graft. During the study, several variants of the aortic linear graft were manufactured and tested. The optimal stiffness and diameter of the nitinol wire were selected based on the results. When creating a bifurcation module, special attention was paid to simplifying the positioning and intravascular assembly of the structure. Implantable modules have been developed for the prosthetics of the main branches of the aorta. Dacron, optimal in terms of fiber structure, was chosen as the material of the woven shell of the graft. Linear extensibility, compactness of the pile, and tensile strength during fenestration were evaluated. To determine the heparin-controlled surgical porosity, experimental samples of stent grafts were tested on a stand simulating arterial blood flow. The wall material of the developed device had a heparin-controlled surgical porosity of 50150 mL/min/cm2 at 120 mm Hg with the possibility of maintaining a controlled endolic. The graft wall created a pressure gradient of no more than 3 mm Hg, and the flow velocity indicators were quite sufficient for adequate perfusion of vital organs. After the inactivation of heparin, blood permeability became zero. The implantation technique of the developed product was implemented on a silicone aortic phantom simulating aneurysm expansion with and without dissection. The phantom contour was filled with a solution simulating the rheological properties of native blood. Pulsating blood flow was simulated using a perfusion pump. Under X-ray control, a stent graft was installed on five large biological samples (sheep). Implantation was performed in the aortic arch with prosthetics of the brachiocephalic trunk and the suprarenal aorta with prosthetics of the visceral branches. With the experiment, we hope that the result will allow us to minimally invasively help patients suffering from aneurysms of any localization.

Novel Self-Expanding Interwoven Nitinol Stent for Treating Femoropopliteal Artery Disease: 12-Month Results of Single-Center First-in-Man Study

Purpose: To evaluate the safety and efficacy of Innospring® stent, a novel self-expanding interwoven nitinol stent, in treating femoropopliteal atherosclerotic lesions. Methods: A prospective, single-center, single-arm, first-in-human study enrolled 15 patients (mean age 73.1 years; 13 men) to evaluate the safety and efficacy of the Innospring® stent monitored by core laboratories. The inclusion criteria were claudication or ischemic rest pain, de novo lesions or nonstented restenosis, >70% stenosis, lesion length <20 cm, and a reference vessel diameter of 4–7 mm. The primary safety endpoint was 30-day major adverse events. The primary efficacy end point was stent patency at 12 months. Follow-up evaluations were conducted at 30 days, 6 months, and 12 months. Results: The lesion length was 6.1 ± 3.5 mm. Fourteen (93.3%) patients had lesions of the superficial femoral artery and 3 (20.0%) patients had lesions of the popliteal artery. Nine (60.0%) patients had moderate-to-severe calcified lesion. Technical and procedural success was 100%. No patients experienced major adverse events in the first 30 days. The Rutherford category showed significant and sustained improvement at 6 and 12 months. The 12-month follow-up radiographs obtained in 13 patients confirmed the absence of stent fractures in 100% of examinations. The cumulative primary stent patency rate at 6 and 12 months were 93.3% and 84.6%, respectively. Conclusion: Stenting of the superficial femoral and popliteal arteries using the Innospring® stent is safe and effective. This competing interwoven nitinol stent may provide superior stent integrity and fracture-resistance as well as serve areas under extreme mechanical stress. Clinical Impact Endovascular recanalization is a widely accepted and recommended treatment for symptomatic peripheral artery diseases. The Innospring® stent is a novel self-expanding interwoven stent containing eight nitinol wires with additional radial force, fracture-resistance, and visibility under fluoroscopy. This first-in-human study using the Innospring® stent in patients with femoropopliteal occlusive disease reported that stenting of the superficial femoral and popliteal arteries using the Innospring® stent is safe and effective. This competing interwoven nitinol stent may provide an impressive stent integrity and fracture-resistance as well as serve areas under extreme mechanical stress.

A Giant Thoracic Aortic Aneurysm Treated by Frozen Elephant Trunk Technique

The treatment of complex aortic pathologies involving the ascending aorta, the aortic arch, and the descending aorta continues to be a challenging situation in aortic surgery. The frozen elephant trunk technique has been increasingly used but there still is an ongoing discussion within the surgical community about the optimal indications. We present herein a patient with a complex aortic aneurysm involving all three segments of the thoracic aorta. The device used is a hybrid prosthesis consisting of a proximal woven polyester graft and a distal self-expanding nitinol stent graft, which can be delivered antegrade into the descending aorta.

Large Animal Models of Cardiovascular Disease: From Training to Translation

ARTICLES DISCUSSED: Blanco-Blázquez, V. et al. Swine models of aneurysmal diseases for training and research. Journal of Visualized Experiments. (181), e63616 (2022). Constantin, I., Tăbăran, A. F. Dissection techniques and histological sampling of the heart in large animal models for cardiovascular diseases. Journal of Visualized Experiments. (184), e63809 (2022). Hao, Y. et al. Transcatheter pulmonary valve replacement from autologous pericardium with a self-expandable nitinol stent in an adult sheep model. Journal of Visualized Experiments. (184), e63661 (2022). Martínez-Falguera, D. et al. Myocardial infarction by percutaneous embolization coil deployment in a swine model. Journal of Visualized Experiments. (177), e63172 (2021). Tubeeckx, M. R. L. et al. Sterile pericarditis in aachener minipigs as a model for atrial myopathy and atrial fibrillation. Journal of Visualized Experiments. (175), e63094 (2021).

Comparative 2-year outcomes of the Misago stent versus other self-expandable nitinol stents for the endovascular treatment of aortoiliac disease.

The Misago iliac stent has not been compared with other stents. This study aimed to evaluate the 2-year clinical outcomes between the Misago stent and other self-expandable nitinol stents for symptomatic chronic aortoiliac disease. This retrospective, single-center observational study enrolled 138 patients (180 limbs; Rutherford classification, between categories 2 and 6) treated with a Misago stent (N.=41) or self-expandable nitinol stent (N.=97) between January 2019 and December 2019. The primary endpoint was patency for up to 2 years. The secondary endpoints were technical success, procedure-related complications, freedom from target lesion revascularization, overall survival, and freedom from major adverse limb events. Multivariate Cox proportional hazards analysis was used to investigate predictors of restenosis. The mean follow-up duration was 710±201 days. The 2-year primary patency rate was comparable between the groups (Misago, 89.6% and self-expandable nitinol stent, 91.0%, P=0.883). The technical success rate was 100% in both groups, and procedure-related complications were equivalent between the groups (1.7% and 2.4%, respectively; P=0.773). Freedom from target lesion revascularization was not significantly different between the groups (97.6% and 94.4%, respectively; P=0.890). The overall survival rate and freedom from major adverse limb events were not significantly different between the groups (77.2% and 70.8%, respectively, P=0.209; 66.9% and 58.4%, respectively, P=0.149). Statin therapy was positively associated with primary patency. The Misago stent for aortoiliac lesions demonstrated comparable and acceptable clinical results of safety and efficacy for up to 2 years compared with other self-expandable stents. Statin use predicted the prevention of patency loss.