ANCD thrombectomy device: in vitro evaluation

2019 ◽  
Vol 12 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Sonia Sanchez ◽  
Ignacio Cortiñas ◽  
Helena Villanova ◽  
Anna Rios ◽  
Iñaki Galve ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Treatment Strategies ◽  
Local Flow ◽  
Guide Catheter ◽  
First Pass ◽  
Thrombectomy Device ◽  
The Mean ◽  
Three Dimensional Models ◽  
Number Of Passes

IntroductionEndovascular treatment of stroke, although highly effective, may fail to reach complete recanalization in around 20% of cases. The Advanced Thrombectomy System (ANCD) is a novel stroke thrombectomy device designed to reduce clot fragmentation and facilitate retrieval by inducing local flow arrest and allowing distal aspiration in combination with a stent retriever. We aimed to assess the preclinical efficacy of ANCD.MethodsSoft red blood cell (RBC)-rich (n=20/group) and sticky fibrin-rich (n=30/group) clots were used to create middle cerebral artery (MCA) occlusions in two vascular phantoms. Three different treatment strategies were tested: (1) balloon guide catheter + Solitaire (BGC+SR); (2) distal access catheter + SR (DAC+SR); and (3) ANCD+SR, until complete recanalization was achieved or to a maximum of three passes. The recanalization rate was determined after each pass.ResultsAfter one pass, ANCD+SR resulted in an increased recanalization rate (94%) for all clots together compared with BGC+SR (66%; p<0.01) or DAC+SR (80%; p=0.04). After the final pass the recanalization rate increased in all three groups but remained higher with ANCD+SR (100%) than with BGC+SR (74%; p<0.01) or DAC+SR (90%; p=0.02). The mean number of passes was lower with ANCD+SR (1.06) than with BGC+SR (1.46) or DAC+SR (1.25) (p=0.01). A logistic regression model adjusted for treatment arm, clot type, and model used showed that both RBC-rich clots (OR 8.1, 95% CI 1.6 to 13.5) and ANCD+SR (OR 3.9, 95% CI 1.01 to 15.8) were independent predictors of first-pass recanalization.ConclusionIn in vitro three-dimensional models replicating MCA-M1 occlusion, ANCD+SR showed significantly better recanalization rates in fewer passes than other commonly used combinations of devices.

scholarly journals Switch Strategy from Direct Aspiration First Pass Technique to Solumbra Improves Technical Outcome in Endovascularly Treated Stroke

2021 ◽  
Vol 18 (5) ◽  
pp. 2670
Author(s):  
Enrico Pampana ◽  
Sebastiano Fabiano ◽  
Gianluca De Rubeis ◽  
Luca Bertaccini ◽  
Alessandro Stasolla ◽  
...  
Keyword(s):  
Added Value ◽  
Stroke Patients ◽  
First Line ◽  
Anterior Circulation ◽  
First Pass ◽  
Procedural Time ◽  
The Mean ◽  
The Difference ◽  
Number Of Passes ◽  
Switch Strategy

Background: The major endovascular mechanic thrombectomy (MT) techniques are: Stent-Retriever (SR), aspiration first pass technique (ADAPT) and Solumbra (Aspiration + SR), which are interchangeable (defined as switching strategy (SS)). The purpose of this study is to report the added value of switching from ADAPT to Solumbra in unsuccessful revascularization stroke patients. Methods: This is a retrospective, single center, pragmatic, cohort study. From December 2017 to November 2019, 935 consecutive patients were admitted to the Stroke Unit and 176/935 (18.8%) were eligible for MT. In 135/176 (76.7%) patients, ADAPT was used as the first-line strategy. SS was defined as the difference between first technique adopted and the final technique. Revascularization was evaluated with modified Thrombolysis In Cerebral Infarction (TICI) with success defined as mTICI ≥ 2b. Procedural time (PT) and time to reperfusion (TTR) were recorded. Results: Stroke involved: Anterior circulation in 121/135 (89.6%) patients and posterior circulation in 14/135 (10.4%) patients. ADAPT was the most common first-line technique vs. both SR and Solumbra (135/176 (76.7%) vs. 10/176 (5.7%) vs. 31/176 (17.6%), respectively). In 28/135 (20.7%) patients, the mTICI was ≤ 2a requiring switch to Solumbra. The vessel’s diameter positively predicted SS result (odd ratio (OR) 1.12, confidence of interval (CI) 95% 1.03–1.22; p = 0.006). The mean number of passes before SS was 2.0 ± 1.2. ADAPT to Solumbra improved successful revascularization by 13.3% (107/135 (79.3%) vs. 125/135 (92.6%)). PT was superior for SS comparing with ADAPT (71.1 min (CI 95% 53.2–109.0) vs. 40.0 min (CI 95% 35.0–45.2); p = 0.0004), although, TTR was similar (324.1 min (CI 95% 311.4–387.0) vs. 311.4 min (CI 95% 285.5–338.7); p = 0.23). Conclusion: Successful revascularization was improved by 13.3% after switching form ADAPT to Solumbra (final mTICI ≥ 2b was 92.6%). Vessel’s diameter positively predicted recourse to SS.

Abstract TP7: Association of Retrieved Thrombus Composition With Measures of Thrombectomy Success

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Neal M Rao ◽  
Laura Solano ◽  
Kunakorn Atchaneeyasakul ◽  
Jiang Hongquan ◽  
Gornbein Jeffrey ◽  
...  
Keyword(s):  
Clinical Features ◽  
Academic Medical Centers ◽  
Endovascular Thrombectomy ◽  
Medical Centers ◽  
Academic Medical ◽  
First Pass ◽  
Thrombectomy Device ◽  
Stent Retrievers ◽  
Hematoxylin And Eosin ◽  
Number Of Passes

Introduction: Emboli retrieved from stroke patients undergoing mechanical thrombectomy vastly differ in histopathologic appearance, likely reflecting varying etiologies of stroke. We investigated whether clot components correlated with clinical features and thrombectomy outcomes. Methods: Retrieved thrombi from endovascular thrombectomy in consecutive AIS-LVO patients at 2 academic medical centers were fixed in formalin and sections stained by hematoxylin and eosin. The RBC, WBC and fibrin percentages of the clot were quantified by a neuropathologist blinded to the clinical details. We evaluated the association of these clot components, patient demographic and clinical features, with TICI score (both ordinal and dichotomized at 2c), AOL score, number of thrombectomy passes, and first-pass substantial recanalization (≥TICI 2b result on the first thrombectomy device pass). Non-parametric values were computed via Spearman correlation and pairwise interaction of clinical features was analyzed by ordinal logistic regression. Results: Among the 75 analyzed patients, mean age was 71.4 (SD 17.7), 50.7% were female and presenting NIHSS mean was 16.1 (SD 7.6). Devices employed were stent retrievers in 71% of patients, aspiration in 10%, and both stent retrievers and aspiration in 19%. Number of passes per procedure was mean 2.16 (SD 1.21). Substantial reperfusion (TICI 2B-3) was achieved in 88% and excellent reperfusion (TICI 2C-3) in 44%. In retrieved thrombi, mean RBC% was 44.8% (SD 31.9) and mean fibrin% was 49.8% (SD 31.4). Rates of first-pass substantial reperfusion, final substantial reperfusion, and final excellent reperfusion were homogenous across wide ranges of retrieved thrombus RBC% and fibrin% in correlation analysis. Conclusion: RBC and fibrin composition range widely among retrieved thrombi causing acute ischemic stroke. Current generation thrombectomy devices perform well across a broad range of clot compositions.

The effect of temperature on in vitro germination and germ tube growth of urediniospores of Tranzschelia discolor

1990 ◽  
Vol 41 (3) ◽  
pp. 479 ◽  
Author(s):  
PJ Ellison ◽  
BR Cullis ◽  
RW Bambach ◽  
PF Kable
Keyword(s):  
Germ Tube ◽  
Three Dimensional ◽  
Tube Growth ◽  
Effect Of Temperature ◽  
In Vitro Germination ◽  
Three Dimensional Models ◽  
C 30 ◽  
Tranzschelia Discolor ◽  
Germ Tube Growth

The effect of temperature on in vitro germination and germ tube growth of urediniospores of Tranzschelia discolor was studied over time under constant temperature conditions. Studies were carried out on 1% water agar in the dark at 3�C, 5�C, 8�C, 10�C, 15�C, 20�C, 25�C, 28�C, 30�C and 32�C. Germination was observed at all temperatures between 5 and 30'C, and occurred rapidly over most of this range. At 2 h, germination exceeded 80% at temperatures between 10 and 28�C, and this level was reached at 3 h at 8�C. Germination at 5 and 30�C was much reduced and at 7 h reached only 44% and 38% respectively. Germ tube growth occurred most vigorously at 15 and 20�C, reaching lengths in excess of 500 8m at 9 h. The optimum range was narrower than that for germination, and growth was reduced or poor at 8�C, 10�C, 25�C and 28�C, which were favourable temperatures for germination. Average germ tube lengths at 9 h at these temperatures were 55, 245, 273 and 62 8m, respectively. Three-dimensional models were derived relating germination and germ tube growth to time and temperature.

scholarly journals Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model

2020 ◽  
Author(s):  
Jawid Madjidyar ◽  
Lars Nerkada ◽  
Naomi Larsen ◽  
Fritz Wodarg ◽  
Johannes Hensler ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
In Vitro Study ◽  
Primary Endpoints ◽  
Key Points ◽  
First Pass ◽  
Stent Retrievers ◽  
Almost All ◽  
Number Of Passes

Purpose A direct aspiration first pass technique (ADAPT) is an effective thrombectomy option in patients with acute ischemic stroke. Balloon guide catheters (BGC) seem to improve the efficacy of stent retrievers and ADAPT. The last generation 6F aspiration catheters require 9F BGCs, which are rigid devices that are challenging to position in a tortuous anatomy. In this experimental study the efficacy of 6F ADAPT alone and 5F ADAPT combined with 8F BGC was evaluated. Materials and Methods Either a fibrin rich (white) clot or an RBC rich (red) clot was placed in the M1 segment of a transparent silicon phantom. Physiological hemodynamic conditions were maintained. The clots were retrieved by 6F aspiration catheter via 8F long sheath or 5F aspiration catheter via a flexible 8F BGC. Thrombectomy was performed under direct visual control. The primary endpoints were the number of passes and the number of distal emboli. Results Ten experiments were made with each clot model and thrombectomy technique (n = 40). Full recanalization could be achieved in every experiment. First pass mTICI 3 could be achieved by 6F ADAPT in 80 % of red clots and 90 % of white clots. Distal emboli were caused in 10 % and 20 %, respectively. When using 5F ADAPT combined with BGC, a first pass mTICI 3 rate of 90 % in red clots and 100 % in white clots could be achieved. A 10 % rate of distal emboli occurred in both groups. In almost all experiments (both techniques), the thrombi clogged the aspiration catheter. No statistically significant differences could be found between the techniques and clot models. Conclusion 6F ADAPT without BGC was as effective as 5F ADAPT combined with a flexible 8F BGC, with both techniques showing high first-pass recanalization rates and low distal emboli rates. Especially in the case of a tortuous anatomy, these setups should be considered as alternatives to a rigid 9F BGC. The thrombus compositions seemed to be irrelevant in this setting. Key Points:  Citation Format

scholarly journals LKB1 kinase-dependent and -independent defects disrupt polarity and adhesion signaling to drive collagen remodeling during invasion

2016 ◽  
Vol 27 (7) ◽  
pp. 1069-1084 ◽  
Author(s):  
Jessica Konen ◽  
Scott Wilkinson ◽  
Byoungkoo Lee ◽  
Haian Fu ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Cell Polarity ◽  
Cancer Metastasis ◽  
Kinase Activity ◽  
Rho Gtpase ◽  
Three Dimensional ◽  
Serine Threonine Kinase ◽  
Collagen Remodeling ◽  
Threonine Kinase ◽  
Three Dimensional Models

LKB1 is a serine/threonine kinase and a commonly mutated gene in lung adenocarcinoma. The majority of LKB1 mutations are truncations that disrupt its kinase activity and remove its C-terminal domain (CTD). Because LKB1 inactivation drives cancer metastasis in mice and leads to aberrant cell invasion in vitro, we sought to determine how compromised LKB1 function affects lung cancer cell polarity and invasion. Using three-dimensional models, we show that LKB1 kinase activity is essential for focal adhesion kinase–mediated cell adhesion and subsequent collagen remodeling but not cell polarity. Instead, cell polarity is overseen by the kinase-independent function of its CTD and more specifically its farnesylation. This occurs through a mesenchymal-amoeboid morphological switch that signals through the Rho-GTPase RhoA. These data suggest that a combination of kinase-dependent and -independent defects by LKB1 inactivation creates a uniquely invasive cell with aberrant polarity and adhesion signaling that drives invasion into the microenvironment.

scholarly journals A Novel Thrombectomy Device: An In Vitro Evaluation of a Prototype Catheter

2021 ◽  
Author(s):  
Yasemin Tanyildizi ◽  
Samantha Krost-Reuhl ◽  
Emily S. Payne ◽  
Axel Heimann ◽  
Oliver Kempski ◽  
...  
Keyword(s):  
Success Rate ◽  
Mechanical Thrombectomy ◽  
Viscous Medium ◽  
Experimental Series ◽  
Arteria Carotis Interna ◽  
First Pass ◽  
Thrombectomy Device ◽  
Series Of Experiments ◽  
Guiding Catheter

Abstract Purpose: This prototype catheter is a newly-developed distal access catheter featuring a self-expanding, flexible, funnel-shaped tip. The purpose of its design is to reduce the risk of thrombus fragmentation during mechanical thrombectomy and improve first-pass recanalization (TICI 3). In this experimental setup, we preclinically evaluated the effectiveness and navigability of the new catheter. Methods: A vessel model was filled with a blood-like-viscous medium, and the image was projected with the corresponding vessel area by camera transmission to correspond to the conditions in an angiography. Thrombi from porcine blood were placed into the Arteria Carotis interna of the vascular model and subsequently mechanically thrombectomized with a stent retriever. In the first part, the prototype was compared to a standard distal-access-catheter without using an external catheter. (N = 20 for each catheter). In the second part the prototype was inserted through a guiding catheter (n=11) to determine the navigability performance. Results: In the first experimental series, mechanical thrombectomy was successful 19 out of 20 times (95% success rate) for the prototype catheter versus 15 out of 20 times (75% success rate) for the standard distal-access-catheter. In the second experimental series, the prototype catheter achieved first-pass recanalization 10 out of 11 times (91 % success rate) and 1 out of 11 times at second pass (9%). Conclusion: This series of experiments demonstrated higher first-pass recanalization rates for the newly-developed funnel-shaped prototype featuring a self-expanding tip in comparison to a cylindrical standard distal-access-catheter.

scholarly journals The domain architecture of JBP1 suggests synergy between J-base DNA binding and thymidine hydroxylase activity

2018 ◽  
Author(s):  
Athanassios Adamopoulos ◽  
Tatjana Heidebrecht ◽  
Jeroen Roosendaal ◽  
Wouter G Touw ◽  
Isabelle Phan ◽  
...  
Keyword(s):  
Dna Binding ◽  
Domain Architecture ◽  
Three Dimensional ◽  
Specific Sequence ◽  
X Ray ◽  
Tet Proteins ◽  
X Ray Scattering ◽  
Sequence Patterns ◽  
Three Dimensional Models

JBP1 (J-DNA Binding Protein 1) contributes to biosynthesis and maintenance of base J (β-D-glucosyl-hydroxymethyluracil), a modification of thymidine (T) confined to pathogenic protozoa. JBP1 has two known functional domains: an N-terminal thymidine hydroxylase (TH) homologous to the 5-methylcytosine hydroxylase domain in TET proteins; and a J-DNA binding domain (JDBD) that resides in the middle of JBP1. Here we show that removing JDBD from JBP1 results in a soluble protein (Δ-JDBD) with the N- and C-terminal regions tightly associated together in a well-ordered domain. This Δ-JDBD domain retains thymidine hydroxylation activity in vitro, but displays a fifteen-fold lower apparent rate of hydroxylation compared to JBP1. Small Angle X-ray Scattering (SAXS) experiments on JBP1 and JDBD in the presence and absence of J-DNA, and on Δ-JDBD, allowed us to generate low-resolution three-dimensional models. We conclude that Δ-JDBD, and not the N-terminal region of JBP1 alone, is a distinct folding unit. Our SAXS-based model supports the notion that binding of JDBD specifically to J-DNA can facilitate hydroxylation a T 12-14 bp downstream on the complementary strand of the J-recognition site. We postulate that insertion of the JDBD module in the Δ-JDBD scaffold during evolution provided a mechanism to synergize between J recognition and T hydroxylation, ensuring inheritance of J in specific sequence patterns following DNA replication.

scholarly journals Shear bond strength of ceramic laminate veneers to finishing surfaces with different percentages of preserved enamel under a digital guided method

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Jiakang Zhu ◽  
Jing Gao ◽  
Luming Jia ◽  
Xin Tan ◽  
Chenyang Xie ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Three Dimensional ◽  
In Vitro Study ◽  
Significant Difference ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Laminate Veneers ◽  
Bonding Surface

Abstract Background The purpose of this in vitro study was to evaluate the effect of the percentages of preserved enamel on ceramic laminate veneers’ (CLVs) shear bond strength (SBS). Methods Seventy extracted human maxillary central incisors were scanned and reconstructed into three-dimensional models. The extracted teeth were then embedded and randomly divided into seven groups (n = 10 per group). Based on digital analyses of the three-dimensional models, guided tooth preparation and bonding procedures were performed individually to form seven different percentages (100%, 80%, 60% 50%, 40%, 20% and 0%) of remaining enamel thickness on the bonding surface. Finally, the SBS test was performed, and the data were statistically analysed by one-way ANOVA with LSD post hoc test (α = 0.05). Results The complete enamel surface exhibited the highest SBS (19.93 ± 4.55 MPa), followed by 80% enamel (19.03 ± 3.66 MPa), 60% enamel (18.44 ± 3.65 MPa), 50% enamel (18.18 ± 3.41 MPa), 40% enamel (17.83 ± 3.01 MPa) and 20% enamel (11.32 ± 3.42 MPa) group. The lowest SBS (9.63 ± 3.46 MPa) was detected in 0% enamel group. No significant difference was observed among the 40–100% enamel groups, while the 20% or 0% enamel group demonstrated a significantly lower mean SBS than the 40% enamel group (p < 0.05). Conclusion The SBS value of CLVs bonded to 100% enamel on the finishing surfaces (nearly 20 MPa) was twice that which bonded to 0% enamel (nearly 10 MPa). Bonding to 100% enamel is the most reliable treatment. When dentin exposure is inevitable, enamel should be preserved as much as possible to maintain good bonding. In addition, 40% of preserved enamel on the bonding surface was the minimal acceptable value to fulfil the requirements of good bonding strength.

Preclinical evaluation of the ANCD thrombectomy device: safety and efficacy in a swine clot model

2020 ◽  
Vol 12 (10) ◽  
pp. 1008-1013 ◽  
Author(s):  
Sonia Sanchez ◽  
Lynn Bailey ◽  
Rebecca Ducore ◽  
Tommy Andersson ◽  
Raul Nogueira ◽  
...  
Keyword(s):  
Mechanical Thrombectomy ◽  
Stent Retriever ◽  
Histopathological Analysis ◽  
Efficacy And Safety ◽  
Guide Catheter ◽  
Vessel Injury ◽  
First Pass ◽  
Thrombectomy Device ◽  
Clinically Significant ◽  
Model Support

BackgroundThe Advanced Thrombectomy System (ANCD) provides a new funnel component designed to reduce clot fragmentation and facilitate retrieval in patients with stroke by locally restricting flow, allowing distal aspiration in combination with a stent retriever (SR).ObjectiveTo evaluate the preclinical efficacy and safety of the ANCD in a swine clot model.MethodsSoft and firm clots were implanted in the lingual and cervical arteries of 11 swine to obtain Thrombolysis in Cerebral Infarction (TICI) 0 blood flow. Mechanical thrombectomy was performed with either a balloon guide catheter+Solitaire 2 stent retriever (BGC+SR, n=13) or ANCD+SR (n=13). TICI flow was evaluated and successful revascularization was defined as TICI 3 (normal perfusion). To characterize safety, a total of 3 passes were performed in each vessel independent of recanalization. Tissues were explanted for histopathological analysis after 3 and 30 days, respectively.ResultsFirst pass reperfusion rates were ANCD+SR: 69% and BGC+SR: 46%. Reperfusion increased after the third pass in both groups (ANCD+SR: 100%, vs BGC+SR: 77%). Recanalization was achieved after an average of 1.4 and 1.9 passes in ANCD+SR and BGC+SR (p=0.095), respectively. Vessel injury was comparable in both groups; endothelial loss at 3 days was the most common injury seen (ANCD+SR: 1.78±1.22; BGC+SR: 2.03±1.20; p=0.73), while other histopathological markers were absent or minimal. Tissues downstream from targeted vessels also showed absence or minimal lesions across both groups.ConclusionsResults in a swine clot model support the high efficacy of the ANCD+SR without causing clinically significant vessel injury potentially related to the new funnel component.

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