Optimization of an endovascular magnetic filter for maximized capture of magnetic nanoparticles.

To computationally optimize the design of an endovascular magnetic filtration device that binds iron oxide nanoparticles and to validate simulations with experimental results of prototype devices in physiologic flow testing. Three-dimensional computational models of different endovascular magnetic filter devices assessed magnetic particle capture. We simulated a series of cylindrical neodymium N52 magnets and capture of 1500 iron oxide nanoparticles infused in a simulated 14 mm-diameter vessel. Device parameters varied included: magnetization orientation (across the diameter, "D", along the length, "L", of the filter), magnet outer diameter (3, 4, 5 mm), magnet length (5, 10 mm), and spacing between magnets (1, 3 mm). Top designs were tested in vitro using 89Zr-radiolabeled iron oxide nanoparticles and gamma counting both in continuous and multiple pass flow model. Computationally, "D" magnetized devices had greater capture than "L" magnetized devices. Increasing outer diameter of magnets increased particle capture as follows: "D" designs, 3 mm: 12.8-13.6 %, 4 mm: 16.6-17.6 %, 5 mm: 21.8-24.6 %; "L" designs, 3 mm: 5.6-10 %, 4 mm: 9.4-15.8 %, 5 mm: 14.8-21.2 %. In vitro, while there was significant capture by all device designs, with most capturing 87-93 % within the first two minutes, compared to control non-magnetic devices, there was no significant difference in particle capture with the parameters varied. The computational study predicts that endovascular magnetic filters demonstrate maximum particle capture with "D" magnetization. In vitro flow testing demonstrated no difference in capture with varied parameters. Clinically, "D" magnetized devices would be most practical, sized as large as possible without causing intravascular flow obstruction.

Readmission after thoracic endovascular aortic repair following blunt thoracic aortic injury.

PURPOSE: Thoracic endovascular aortic repair (TEVAR) is increasingly utilized to treat blunt thoracic aortic injury (BTAI), but post-discharge outcomes remain underexplored. We examined 90-day readmission in patients treated with TEVAR following BTAI. METHODS: Adult patients discharged alive after TEVAR for BTAI in the Nationwide Readmissions Database between 2016 and 2019 were included. Outcomes examined were 90-day non-elective readmission, primary readmission reasons, and 90-day mortality. As a complementary analysis, 90-day outcomes following TEVAR for BTAI were compared with those following TEVAR for acute type B aortic dissection (TBAD). RESULTS: We identified 2085 patients who underwent TEVAR for BTAI. The median age was 43 years (IQR, 29-58), 65% of all patients had an ISS ≥ 25, and 13% were readmitted within 90 days. The main primary causes for readmission were sepsis (8.8%), wound complications (6.7%), and neurological complications (6.5%). Two patients developed graft thrombosis as primary readmission reasons. Compared with acute TBAD patients, BTAI patients had a significantly lower rate of readmission within 90 days (BTAI vs. TBAD; 13% vs. 29%; p < .001). CONCLUSION: We found a significant proportion of readmission in patients treated with TEVAR for BTAI. However, the 90-day readmission rate after TEVAR for BTAI was significantly lower compared with acute TBAD, and the common cause for readmission was not related to residual aortic disease or vascular devices. This represents an important distinction from other patient populations treated with TEVAR for acute vascular conditions. Elucidating differences between trauma-related TEVAR readmissions and non-traumatic indications better informs both the clinician and patients of expected post-discharge course. Level of evidence/study type: IV, Therapeutic/care management.

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

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

In vitro and In vivo assessment of a novel organ perfusion stent for successful flow separation in donation after cardiac death.

Shortage of healthy donors' organs has appeared as one of the main challenges for organ transplantation. This study focuses on the novel endovascular device development to increase the number of available organs from cardiac death donors. The primary objective of this study is the design validation of a newly developed stent graft for the abdominal organ perfusion with cardiac blood flow isolation. In this paper, the effectiveness of the device design has been validated via the assessment of the device performance both in vitro and in vivo. The radial force of stent structure was first numerically analyzed using finite element method, then was quantified experimentally. The blood perfusion parameters were investigated to demonstrate their effect on the blood delivered to the abdominal organs, maintaining the organs healthy for donation. In vitro flow leakage was measured using a 3-D printing-based silicone aortic model to evaluate the isolation between cardiac flow and perfusion flow with minimum values. Following the design validation process, a functional prototype stent graft has been successfully fabricated using optimized laser welding conditions and subsequent joining processes. In vivo porcine study results have demonstrated smooth delivery and successful placement of the device showing complete cardiac flow separation isolating abdominal regions only with the oxygenated blood flow.

Pipeline Embolization Device for the Treatment of Unruptured Intracranial Dissecting Aneurysms.

Background: Intracranial dissecting aneurysms (IDAs) are rare but pose significant challenges to treatment. The pipeline embolization device (PED) has been demonstrated to be an effective treatment option with excellent outcomes. Herein, we report our experience with patients treated with the PED for unruptured IDAs. Methods: We retrospectively reviewed our hospital database and identified patients who were treated with PEDs for unruptured IDAs between March 2016 and September 2020. Data including demographics, clinical presentation, aneurysm characteristics, procedural details, intra- or peri-procedural complications, and follow-up details were collected. Results: Eighty patients (61 men, 76.25%) were treated with PED for unruptured IDAs. The most common symptoms were headache (34, 42.5%), dizziness (29, 36.25%), and nausea or vomiting (15, 18.75%). Of these patients, 73 had one aneurysm, and seven harbored two aneurysms. All of them achieved successful PED deployment. Six patients experienced intra- or peri-procedural complications including perforator artery occlusion, thromboembolic, hemorrhagic events, and falling of the stent into the aneurysm sac. Follow-up with digital subtractive angiography was available for 29 patients with a median of 6 months, and 28 (96.56%) patients had aneurysm occlusion. Late thrombosis occurred in four patients, and two of them had unfavorable outcomes. Clinical follow-up showed that a favorable clinical outcome was achieved in 76 (95%) patients, and the mortality rate was 3.75%. Conclusion: Treating unruptured IDAs is safe and effective with long-term favorable clinical and angiographic outcomes. However, the complications of this treatment should be noted. Careful selection of appropriate patients and individualized antiplatelet therapy might be needed.

Corrigendum: Pipeline Embolization Device for the Treatment of Unruptured Intracranial Dissecting Aneurysms.

[This corrects the article DOI: 10.3389/fneur.2021.691897.].

Amplatzer vascular plug IV in the treatment of high flow renal arteriovenous fistula: Case considerations.

Renal arteriovenous fistula is classified into idiopathic, acquired and congenital. Endovascular therapy has become the gold standard compared to surgery. We present the embolization procedure of a renal fistula postbiopsy in a 57-year-old female patient through the use of St. Jude Medical Amplatzer vascular Plug IV. Although numerous embolizing agents are available, plug type IV has numerous advantages in terms of procedure times, speed of embolization and precision of the occlusion, but with a relative increase in costs.

Transcirculation Approach for Endovascular Embolization of Intracranial Aneurysms, Arteriovenous Malformations, and Dural Fistulas: A Multicenter Study.

BACKGROUND: Unfavorable anatomy can preclude traditional anterograde endovascular interventions. Transcirculation approaches, which consist of primary catheterization of a target artery from the contralateral side or opposite cerebral circulation, can provide alternative pathways for successful treatment of these patients. We aimed to assess the safety, efficacy, and outcomes of endovascular embolization through transcirculation approaches. METHODS: Nine centers provided retrospective data on patients who underwent transcirculation procedures for embolization of intracranial aneurysms (IAs), dural arteriovenous fistulas (dAVFs), and arteriovenous malformations (AVMs). Raymond-Roy Occlusion Classification (RROC) grades and degree of obliteration were used to evaluate treatment success. Minor/major complications and clinical/angiographic outcomes were also assessed. A review of the literature reporting patients who underwent transcirculation embolizations was also performed. RESULTS: Forty patients were included in the study (34 IAs, 3 AVMs, and 3 dAVFs). Most IAs (22/34, 64.7%) were treated electively. Three AVMs and 2 dAVFs presented ruptured. RROC grade I-II was achieved in 97% of IAs. All AVMs and dAVFs were completely obliterated. One patient developed a transient arterial thrombus that was successfully treated with intravenous tirofiban. The most common indications for a transcirculation approach were difficult access angle of the target lesion (42.5%) and occlusion of the parent artery (27.5%). The review of the literature pooled 152 IAs treated via transcirculation approaches. Most common locations were the basilar tip (27%), posterior inferior cerebellar artery (25%), and internal carotid artery (15.1%). The posterior communicating artery was crossed in 60 (39.5%), anterior communicating artery in 48 (31.6%), and vertebral artery in 37 (24.3%) patients. Primary coiling alone was performed in 22 (14.5%), stent-assisted coiling in 67 (44.1%), balloon-assisted coiling in 36 (23.7%), stent-assisted coiling + balloon-assisted coiling in 20 (13.2%) and flow diversion in 7 (4.6%) patients. After intervention, 142 (93.4%) IAs achieved successful RROC grades I-II. Two major complications (1.3%) leading to death were reported, both of which were intraprocedural aneurysmal ruptures with massive subarachnoid hemorrhage and herniation. After a mean angiographic follow-up of 11.3 months, only 6/108 (5.6%) IAs showed intrasaccular filling/recurrence. CONCLUSIONS: Transcirculation approaches seem to be safe and effective in the treatment of IAs, dAVFs, and AVMs. The most common indication for a transcirculation approach is the presence of a difficult angle to access the target lesion and occlusion of the parent artery.

Transcirculation Approach for Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter Study and Review of the Literature.

Background: Transcirculation approaches, which consist of primary catheterization of a target artery from the contralateral side or opposite cerebral circulation, provide alternate endovascular routes when anterograde interventions are not feasible. We aimed to assess the safety and efficacy of mechanical thrombectomy (MT) through a transcirculation route. Methods: Six centers provided retrospective data on acute ischemic stroke (AIS) patients who underwent MT via transcirculation approaches. Demographics and technical details of the endovascular intervention were collected. Recanalization rates, peri-procedural complications and clinical/angiographic outcomes immediately after the procedure and at last available follow-up were assessed. A review of the literature reporting on AIS patients whom underwent transcirculation MT was also performed. Results: Our multicenter study included 14 AIS patients treated through transcirculation routes. Mean age was 57.8 ± 11.9 years, and 10 (71.4%) were men. Mean NIHSS at admission was 18.4 (range 8-27). TICI 2b-3 recanalization was achieved in 10/14 (71.4%) patients. Three patients died after intervention: one due to late recanalization, one due to acute in-stent thrombosis, and one due to a procedure-related thromboembolic brainstem infarct. Of 11 surviving patients with follow-up available (mean 9.7 months), mRS 0-2 was achieved in 6 (54.5%) cases. Our review of the literature pooled a total of 37 transcirculation MT cases. Most common occlusions were tandem lesions (ICA + MCA = 64.9%) and BA + bilateral VA (18.9%). ACOM and PCOM were crossed in 18 (48.6%) cases each; one patient required a combined ACOM-PCOM approach. Primary recanalization technique included intra-arterial (IA) thrombolytics alone in 10 (27%), angioplasty ± stenting in 6 (16.2%), stent-retriever in 8 (21.6%), contact aspiration in 6, and combined (MT ± IA-thrombolytics) in 6 cases. Twenty-eight (75.7%) AIS patients achieved successful TIMI 2-3/TICI 2b-3 recanalization. After a mean follow-up of 6.7 months, 23/31 (74.2%) patients achieved a favorable functional outcome. Conclusions: Transcirculation approaches may be used to access the target lesion when the parent artery cannot be crossed through conventional antegrade routes. These techniques are feasible but should be reserved as a bailout maneuver when anterograde MT is not possible. Newer endovascular devices have improved neurological and angiographic outcomes in transcirculation cases.

Construction of Aneurysmal Models on a Curved Vascular Segment of a Carotid Siphon Model for Testing Endovascular Devices.

OBJECTIVE: To investigate construction of an aneurysm on a curved vascular segment of a carotid siphon model for testing endovascular devices. METHODS: Preshaped carotid siphon models of polytetrafluoroethylene were constructed from a human cadaver for confining canine common carotid artery (CCA). The canine right external jugular vein was isolated and harvested to make a venous pouch by suturing 1 end. The right CCA was isolated, and the venous pouch was sutured onto the right CCA to make an aneurysm. The right CCA segment containing the aneurysm was excised and guided through the preshaped polytetrafluoroethylene carotid siphon model using a guidewire with the aneurysm adjusted to protrude out of the round window of the siphon model. The siphon model together with the aneurysm was sutured end-to-end onto the left CCA to form a carotid siphon model in vivo. RESULTS: Five canine models were successfully constructed; the average construction time was 120 minutes. All aneurysms and siphon models remained patent 7 days and 2 weeks later. Five covered stents for intracranial use were tested for flexibility and apposition to the vascular wall in the curved segment of the carotid siphon model in vivo. All the covered stents passed the tortuous siphon model without much difficulty and were deployed successfully to cover the aneurysm orifice without endoleak. CONCLUSIONS: The carotid siphon model in vivo can simulate well the geometry of the human carotid siphon segment and can be used to test endovascular devices for interventions.

Effectiveness of Endovascular Recanalization Treatment for M2 Segment Occlusion: Comparison Between Intracranial ICA, M1, and M2 Segment Thrombectomy.

RATIONALE AND OBJECTIVES: Mechanical thrombectomy is common practice in proximal anterior vessel occlusion. However, it remains unclear whether peripheral artery occlusions should be treated as well. This retrospective study aimed to prove the effectiveness of endovascular recanalization treatment for the M2 segment by comparison of intracranial internal carotid artery (ICA), M1 segment, and M2 segment thrombectomy. MATERIALS AND METHODS: All patients who received endovascular treatment for distal ICA, M1, or M2 segment occlusions between January 2010 and July 2017 at our center were re-analyzed with respect to reperfusion success, interventional and clinical parameters. Statistical analysis was performed by Mann Whitney test, Chi square test, and Spearman correlation analysis. RESULTS: A total of 261 patients (median age, 72 years), 100 with ICA, 137 with M1, and 24 with M2 segment occlusion, were included. Duration of endovascular treatment was significantly longer in ICA occlusions (median, 83 minutes, p < 0.001) compared to M1 (56 minutes) or M2 segment occlusions (49 minutes). Recanalization and reperfusion success and rate of endovascular complications did not differ between occlusion sites (AOL, p = 0.071; mTICI, p = 0.540; complications, p = 0.064). No significant difference in revascularization success was found between the different thrombectomy devices (direct thrombus aspiration, stent retrieving, or a sequential combined approach; p = 0.112). Successful M2 recanalization (mTICI 2b-3) correlated significantly with stronger posttherapeutic NIHSS reduction (r = 0.691, p < 0.001). CONCLUSION: We found endovascular treatment of M2 segment occlusions as safe and successful as endovascular therapy of the ICA or M1 segment, with stronger posttherapeutic NIHSS reduction after successful compared to insufficient M2 recanalization.

A novel customizable stent graft that contains a stretchable ePTFE with a laser-welded nitinol stent.

Customizable medical devices have recently attracted attentions both in dental and orthopedic device fields, which can tailor to the patients' anatomy to reduce the length of surgery time and to improve the clinical outcomes. However, development of the patient specific endovascular device still remains challenging due to the limitations in current 3D printing technology, specifically for the stent grafts. Therefore, our group has investigated the feasibility of a highly stretchable expanded-polytetrafluoroethylene (ePTFE) tube as a customizable graft material with the laser-welded nitinol backbone. In this study, a highly stretchable ePTFE tube was evaluated in terms of mechanical behaviors, in vitro biocompatibility of ePTFE with various stretchiness levels, and capability for the integration with the laser-welded customizable nitinol stent backbone. A prototype stent graft for the swine's venous size was successfully constructed and tested in the porcine model. This study demonstrates the ability of ePTFE tube to customize the stent graft without any significant issue, for example, sweating through the stretched pores in the ePTFE tube, as well as in vivo feasibility of the device for bleeding control. This novel customizable stent graft would offer possibilities for a wide range of both current and next-generation endovascular applications for the treatment in vascular injuries or diseases. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 911-923, 2019.

Increased affinity of endothelial cells to NiTi using ultraviolet irradiation: An in vitro study.

Nickel-titanium alloy (NiTi) is one of the most popular materials used endovascularly because of its shape memory and superelasticity. The NiTi device needs to be covered by endothelial cells after being placed in the blood vessel to reduce ischemic complications. The objective of this study was to examine the impact of ultraviolet (UV) irradiation on the biocompatibility of NiTi surfaces with endothelial cells. NiTi sheets were treated with UV irradiation for 48 h and human aorta derived endothelial cells were used in this study. UV irradiation converted the NiTi surface to hydrophilic state and increased albumin adsorption. The number of endothelial cell migration, attachment, proliferation as well as their metabolic activity were significantly increased on UV treated NiTi. This study provides the first evidence of the photoactivation of NiTi surfaces by UV irradiation and demonstrates improved biocompatibility of UV-treated NiTi surfaces with vascular endothelial cells. These results suggest that UV irradiation may promote endothelialization of NiTi devices in blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1034-1038, 2018.

Use of Pipeline Endovascular Device in Patients with Nickel Allergies.

BACKGROUND: Metal allergies affect a significant portion of the population; intracranial flow diverters contain many of the most commonly allergenic metals. Prior literature has suggested patch testing for all patients with documented or suspected metal allergies before intracranial flow diverter placement; however, there remains a paucity of reports of patients with documented metal allergies undergoing intracranial flow diversion. CASE DESCRIPTION: We report 2 patients with documented nickel allergies, confirmed via patch testing by a board-certified allergist, and unruptured intracranial aneurysms that underwent treatment with the PED. Both patients developed contact dermatitis when a PED was affixed to their skin during their preoperative workup. Follow-up arteriography at 12 and 36 months post PED placement showed no evidence of in-stent stenosis or intimal hyperplasia, and both patients never developed systemic allergic reactions. CONCLUSIONS: In 2 patients with known nickel allergies and intracranial aneurysms treated with the PED, there were no clinically or radiographically apparent allergic reactions at greater than 2 years of follow-up.

Testing the Medina embolization device in experimental aneurysms.

OBJECTIVE: The Medina embolization device (MED) is a novel, braided self-expanding endovascular device designed to occlude aneurysms by constructing an in situ intrasaccular flow diverter. Although a single device can be positioned at the neck of simple spherical in vitro aneurysms, the best way to occlude more complex in vivo aneurysms (using multiple MEDs or a combination of MEDs and platinum coils) is currently unknown. METHODS: Fifty-two aneurysms of 3 different types were created in 31 canines, yielding 48 patent aneurysms. Treatments were randomly allocated by drawing lots: group 1, MEDs alone (n = 16); group 2, MEDs plus standard platinum coils (n = 16); and group 3, control aneurysms treated with coils alone (n = 16). Angiographic results were scored and compared immediately following treatment completion and at 3 months. Specimens were photographed and the extent of neointimal closure of the aneurysmal neck scored, followed by histopathological analyses. RESULTS: Angiographic scores of 0 or 1 (occlusion or near occlusion) were initially obtained in 2 of 16 (12.5%, 95% CI 1.6%-38.3%) group 1 (MEDs alone), 3 of 16 (18.7%, 95% CI 4%-45.6%) group 2 (MEDs plus coils), and 10 of 16 (62.5%, 95% CI 35.4%-84.8%) group 3 (coils alone) aneurysms (p = 0.005). At 3 months, scores of 0 or 1 were found in 11 of 16 (68.7%, 95% CI 41.3%-89.0%) group 1, 9 of 16 (56.2%, 95% CI 29.9%-80.2%) group 2, and 8 of 16 (50%, 95% CI 24.7%-75.3%) group 3 aneurysms (p = 0.82). Neointimal scores were similar for the 3 treated groups (p = 0.66). CONCLUSION: Endovascular treatment of experimental aneurysms with MEDs or MEDs and coils showed angiographic occlusion and neointimal scores at 3 months that were similar to those achieved with standard platinum coiling.

Construction of an in vivo carotid siphon model for testing endovascular devices for neuro-interventions.

Objective The aim of this study was to construct an in vivo carotid siphon model for testing neurovascular devices for endovascular interventions. Methods A model of a human carotid siphon was pre-shaped using a glass tube from a human cadaver and used to confine a segment of one side of the common carotid artery (CCA) in canines. This segment of CCA with the glass carotid siphon on was interposed end-to-end onto the contralateral CCA so as to simulate a human carotid artery siphon in vivo. Two weeks later, the siphon model was evaluated using computed tomography angiography and digital subtraction angiography, and the covered stent specially designed for intracranial vasculature was navigated through the siphon model for a longitudinal flexibility test. Results All dogs tolerated the procedures well, and the artificial siphon model in vivo provided realistic conditions for device testing. Two weeks later, the in vivo carotid siphon model remained patent with no thrombosis. Five covered stents were navigated to pass through five siphon models successfully, with vasospasm occurring in two siphons. Conclusion Construction of an in vivo siphon model in dogs with a glass tube is feasible and useful for the test of endovascular devices for treating neurovascular diseases.

Virtual stenting workflow with vessel-specific initialization and adaptive expansion for neurovascular stents and flow diverters.

Endovascular intervention using traditional neurovascular stents and densely braided flow diverters (FDs) have become the preferred treatment strategies for traditionally challenging intracranial aneurysms. Modeling stent and FD deployment in patient-specific aneurysms and its flow modification results prior to the actual intervention can potentially predict the patient outcome and treatment optimization. We present a clinically focused, streamlined virtual stenting workflow that efficiently simulates stent and FD treatment in patient-specific aneurysms based on expanding a simplex mesh structure. The simplex mesh is generated using an innovative vessel-specific initialization technique, which uses the patient's parent artery diameter to identify the initial position of the simplex mesh inside the artery. A novel adaptive expansion algorithm enables the acceleration of deployment process by adjusting the expansion forces based on the distance of the simplex mesh from the parent vessel. The virtual stenting workflow was tested by modeling the treatment of two patient-specific aneurysms using the Enterprise stent and the Pipeline Embolization Device (commercial FD). Both devices were deployed in the aneurysm models in a few seconds. Computational fluid dynamics analyses of pre- and post-treatment aneurysmal hemodynamics show flow reduction in the aneurysmal sac in treated aneurysms, with the FD diverting more flow than the Enterprise stent. The test results show that this workflow can rapidly simulate clinical deployment of stents and FDs, hence paving the way for its future clinical implementation.

The DERIVO Embolization Device in the Treatment of Intracranial Aneurysms: Short- and Midterm Results.

OBJECTIVE: The DERIVO embolization device (DED) is a new nitinol flow diverter stent manufactured for the treatment of intracranial aneurysms. In this study, we evaluated the safety and efficacy of the DED in the treatment of intracranial aneurysms and present the short- and midterm results. METHODS: We treated 34 aneurysms using 26 devices in 24 patients with wide-necked, mostly medium-sized, and fusiform aneurysms. Fourteen of the patients included in the study were women and the other 10 were men. Headache was the most frequent symptom. Although 31 (91.2%) aneurysms were in the anterior circulation, 3 (8.8%) were in the posterior. Intracranial stent medication was accomplished in all patients. All patients were evaluated 1 day later for any ischemic lesion with diffusion-weighted imaging. The first and second follow-up angiograms were planned to be performed after 3 and 9 months. RESULTS: In all patients, the treatment was successful. No hemorrhagic complication was seen on computed tomography scan performed immediately after the procedure. All patients were discharged without any neurologic deficit. Although 20 (71.4%) of 28 aneurysms in 20 patients were totally closed on the 3-month follow-up angiogram, 14 (77.8%) of 18 aneurysms in 9 patients were totally closed on the 9-month follow-up. General morbidity was 8.4%, and mortality was 4.3%. CONCLUSIONS: The DED seems effective and safe in the treatment of different kinds of intracranial aneurysms.

An overview of thin film nitinol endovascular devices.

Thin film nitinol has unique mechanical properties (e.g., superelasticity), excellent biocompatibility, and ultra-smooth surface, as well as shape memory behavior. All these features along with its low-profile physical dimension (i.e., a few micrometers thick) make this material an ideal candidate in developing low-profile medical devices (e.g., endovascular devices). Thin film nitinol-based devices can be collapsed and inserted in remarkably smaller diameter catheters for a wide range of catheter-based procedures; therefore, it can be easily delivered through highly tortuous or narrow vascular system. A high-quality thin film nitinol can be fabricated by vacuum sputter deposition technique. Micromachining techniques were used to create micro patterns on the thin film nitinol to provide fenestrations for nutrition and oxygen transport and to increase the device's flexibility for the devices used as thin film nitinol covered stent. In addition, a new surface treatment method has been developed for improving the hemocompatibility of thin film nitinol when it is used as a graft material in endovascular devices. Both in vitro and in vivo test data demonstrated a superior hemocompatibility of the thin film nitinol when compared with commercially available endovascular graft materials such as ePTFE or Dacron polyester. Promising features like these have motivated the development of thin film nitinol as a novel biomaterial for creating endovascular devices such as stent grafts, neurovascular flow diverters, and heart valves. This review focuses on thin film nitinol fabrication processes, mechanical and biological properties of the material, as well as current and potential thin film nitinol medical applications.

Experiencia multicéntrica colombiana durante tres años en el cierre percutáneo de la comunicación interventricular con diferentes dispositivos oclusores: propuesta para la simplicación de la técnica en pacientes seleccionados / Colombian multicentric experience during three years for percutaneous closure of interventricular septal defect with different occluder devices: proposal for technique simplification in selected patients

Objetivos: se describe la experiencia del cierre endovascular de comunicación interventricular realizada durante tres años en diferentes centros de cardiología intervencionista, y se destaca el resultado en un grupo de pacientes seleccionados en quienes dicho procedimiento se efectuó mediante el uso de un dispositivo de última generación diseñado para el cierre de ductus arterioso. Pacientes: entre junio de 2006 hasta octubre de 2009 se sometió un total de 34 pacientes a la técnica de oclusión de comunicación interventricular por vía endovascular. La indicación del procedimiento incluyó sobrecarga de volumen, sobrecarga de presión y volumen, falla cardiaca crónica, prolapso de válvula aórtica con insuficiencia y lesión traumática. La edad promedio fue de 12,9 años y el peso fue de 36 kilos. Se evidenció un predominio del sexo masculino (53 porciento. El promedio de cálculo de flujos demostró Qp/Qs de 1,71 a 1 y el de resistencias vasculares pulmonares fue 1,18 U Wood/m2. Materiales y Métodos: el dispositivo PM VSD Occluder se implantó con la técnica clásica (62,5 porciento) mientras que el dispositivo Duct Occluder II (28,1 porciento) se utilizó con la técnica simplificada propuesta. Se usó anestesia general en 98 porciento de los casos, 60 porciento fueron guiados con fluoroscopia y ecocardiografía transesofágica y 40 porciento con transtorácica. Resultados: el tamaño del defecto varió entre 4 y 12 mm. El 91 porciento de los pacientes tenía un defecto septal aislado. La mediana del tiempo quirúrgico se cuantificó en 56 minutos, siendo mayor en el grupo en el cual se utilizó la técnica clásica (85 min) en comparación con aquel grupo en el que se empleó la técnica simplificada con un promedio de 36 minutos...

Objectives: we describe the experience of the endovascular closure of interventricular communication performed for three years in different centers of interventional cardiology and highlight its result in a group of selected patients in whom such procedure was made by the use of a last generation device designed for the closure of ductus arteriosus. Methodology: between June 2006 and October 2009, a total of 34 patients underwent endovascular occlusion for interventricular septal defect. Indication of this procedure included volume overload, pressure and volume overload, chronic congestive heart failure, aortic valve prolapse with insufficiency and traumatic injury. Mean age was 12,9 years old and mean weight was 36 kg. A prevalence in male gender (53 porciento) was evidenced. Main blood flow calculation showed Qp / Qs of 1.71 to 1 and the pulmonary vascular resistance was 1.18 U Wood/m2. Materials and methods: PM VSD occluder device was implanted with the classic technique (62,5 porciento) while the Duct Occluder II (28,1 porciento) was used with the proposed simplified technique. General anesthesia was used in 98 porciento cases; 60 porciento were guided by fluoroscopy and transesophageal echocardiography and 40 porciento with transthoracic echocardiography. Results: size of the defect varied from 4 to 12 mm. 91 porciento of patients had an isolated septal defect. Mean surgical time was 56 min, being longer in the group in which the classic technique was used (85 min) compared with the group in which the technique used was the simplified one, with a mean duration of 36 min. Mean hospital stay was estimated in 36 hours. Follow up: complete closure was documented in 100 porciento of patients at 30 days. There were three adverse events due to minor complications related to transient rhythm disturbances...