PERFORMANCE TEST AND EXPERIMENTAL STUDY OF SPECIAL STENT FOR TREATMENT OF ILIAC VEIN STENOSIS

Objective: Animal experiments and clinical trials were carried out to evaluate the efficiency of a new stent for the treatment of iliac vein stenosis. Methods: The new iliac vein stent and the control stent were implanted, respectively, into the 12 experimental pigs. Digital Subtraction Angiography was done separately at the same day, 14th, 30th, 60th and 90th day after stent implantation to observe the stent deployment. One patient was implanted with a new iliac vein stent. Digital subtraction angiography (DSA) was done after the operation to calculate the lumen loss value and lumen loss rate of the stent and evaluate the performance of the new iliac vein stent at 12 months of follow-up. Results: The mechanical experiment and finite element analysis of the stent proved that the radial support force of the new stent is significantly better than that of the control stent. In animal experimental verification, both groups of stent were released satisfactorily during implantation. No obvious stent displacement was found at each time point. The patency rate of stents was 100%. Except for a small amount of old thrombosis in the stent in the control group, no other stents were found in that condition. The diameter of the stent lumen was retracted in different degrees in both groups after the operation, but no significant statistical difference was found in the comparison of the stent lumen loss rate at each relative inspection day. Conclusion: The new nickel-titanium alloy iliac vein stent has excellent radial support performance, which may be an ideal iliac vein stent.

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Thrombosed Cavo-Portal Hemi-Transposition Salvaged by Digital Subtraction Angiography and Self Expanding Metallic Stent Deployment-Report of First Case and Review of Literature

Journal of Gastrointestinal & Digestive System ◽

10.4172/2161-069x.1000500 ◽

2017 ◽

Vol 07 (02) ◽

Author(s):

Naganathan S ◽

Gupta S ◽

Rastogi H

Keyword(s):

Digital Subtraction Angiography ◽

Metallic Stent ◽

Digital Subtraction ◽

Review Of Literature ◽

Stent Deployment ◽

First Case

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Finite element analysis and animal test verification of nitinol alloy iliac vein stent performance

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406219861127 ◽

2019 ◽

Vol 233 (17) ◽

pp. 6197-6208 ◽

Cited By ~ 2

Author(s):

HQ Feng ◽

SB Wang ◽

YG Wang ◽

XQ Li ◽

YJ Mao ◽

...

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Fatigue Strength ◽

Equivalent Stress ◽

Iliac Vein ◽

Control Group ◽

Element Analysis ◽

Animal Test ◽

Significant Difference ◽

Test Verification

The design and fatigue strength of a nitinol iliac vein stent (NIVS) proposed in this study are assessed using the finite element analysis method. The influence of stent diameter and different release scales on its strength, lifespan and biomechanical properties of the vein wall is analyzed for self-developed NIVS of three different diameters (12, 14 and 16mm) and length of 26mm, which were implanted into the corresponding iliac vein with different release scales (80% and 90%). The results obtained strongly indicate that with an increase in the release scale, the equivalent elastic strain, safety factors of fatigue strength, and equivalent stress of the vessel wall exhibit a downward trend, while the most stressed cross-section coincides with the arc of stent-connecting rods. The efficiency and safety of the above stents were verified by in vivo tests (with observation periods of 30, 90 and 180 days after operation) on ten lab pigs, which underwent NIVS implantation into the iliac veins, with observation of hemodynamics, stent deployment, presence/absence of thrombosis, and monitoring of stent lumen loss and its rate. During the animal test verification, the stent release was satisfactory, while the radiography revealed no obvious stent displacement at different time points. In addition, the patency rate of the stent was 100%. Except for the control group, where a small amount of old thrombus was found, other stents exhibited no thrombus; at the same time, there was no significant difference in the lumen loss rate of the stent at each time point. Therefore, the proposed nitinol NIVS samples demonstrated a good performance, accurate positioning, and release, in addition to the reduced risk of lateral iliac vein thrombosis.

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Application of zero echo time MR angiography in follow-up of intracranial aneurysm remnant and in-stent lumen after embolization: a comparison study with digital subtraction angiography

Acta Radiologica ◽

10.1177/0284185119865721 ◽

2019 ◽

Vol 61 (4) ◽

pp. 480-486

Author(s):

Yan Song ◽

Peng Qi ◽

Juan Huang ◽

Sheng Jiao ◽

Jintao Zhang ◽

...

Keyword(s):

Intracranial Aneurysm ◽

Digital Subtraction Angiography ◽

Predictive Value ◽

Mr Angiography ◽

Time Of Flight ◽

Digital Subtraction ◽

Treatment Needs ◽

Invasive Approach ◽

Echo Time ◽

Stent Lumen

Background Intracranial aneurysm with endovascular treatment needs to be followed-up with a proper imaging method. Purpose To evaluate the performance of magnetic resonance angiography (MRA) with zero echo time at 1.5-T in assessing the intracranial aneurysm remnant and in-stent lumen as compared with time-of-flight MRA, with digital subtraction angiography as the gold standard. Material and Methods A total of 46 patients (17 men; mean age = 56.6±13.7 years) with 54 aneurysms who underwent coil embolization with or without stent were enrolled in this study. The presence of aneurysm remnant and the visualization of in-stent lumen were evaluated. The agreement of remnant identification between MRA with zero echo time and time-of-flight MRA with digital subtraction angiography was evaluated using Cohen’s kappa analysis. The performance of in-stent lumen visualization between MRA with zero echo time and time-of-flight MR angiography was compared with Chi-square test. Results Of 54 aneurysms, 27 were found to have remnants by digital subtraction angiography. The kappa value in identification of remnant of aneurysm was 0.852 between MRA with zero echo time and digital subtraction angiography and 0.741 between time-of-flight MRA and digital subtraction angiography. In detecting remnant of aneurysm, the sensitivity, specificity, positive predictive value, and negative predictive value were 96.3%, 88.9%, 89.7%, and 96.0% for MRA with zero echo time and 91.7%, 83.3%, 81.5%, and 92.6% for time-of-flight MRA, respectively. In visualizing in-stent lumen, MRA with zero echo time had better performance than time-of-flight MRA ( P < 0.001). Conclusion MR angiography with zero echo time might be a better non-invasive approach in assessing remnant of aneurysms and in-stent lumen as compared with time-of-flight MRA.

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Intravascular Flow Detection During Transforaminal Epidural Injections: A Prospective Assessment

January 2018 - Pain Physician ◽

10.36076/ppj.2014/17/21 ◽

2014 ◽

Vol 17;1 (1;17) ◽

pp. 21-27

Author(s):

Omar El Abd

Keyword(s):

Digital Subtraction Angiography ◽

Control Group ◽

Safe Procedure ◽

Digital Subtraction ◽

Traditional Methods ◽

Steroid Injections ◽

Epidural Steroid Injections ◽

Number Of Patients ◽

Epidural Steroid ◽

The Impact

Background: Transforaminal epidural steroid injections (TFESI) are a mainstay in the treatment of spine pain. Though this commonly performed procedure is generally felt to be safe, devastating complications following inadvertent intra-arterial injections of particulate steroid have been reported. The use of digital subtraction angiography (DSA) has been suggested as a means of detecting intra-arterial needle placements prior to medication injection. Objective: To examine the efficacy of DSA in detecting intra-arterial needle placements during TFESI. Study Design: Prospective cohort study evaluating the impact of DSA on detecting intra-arterial needle placements during TFESI. Methods: We enrolled 150 consecutive patients presenting to a university-affiliated spine center with discogenic and/or radicular symptoms affecting the cervical, lumbar, and sacral regions. For each injection, prior to imaging with DSA, traditional methods for vascular penetration detection were employed, including the identification of blood in the needle hub (flash), negative aspiration of blood prior to injection, and live fluoroscopic injection of contrast. Once these tests were performed and negative for signs of intra-arterial needle placement, DSA imaging was utilized prior to medication administration for identification of vascular flow. Results: A total number of 222 TFESI were performed, 41 injections at the cervical levels (18.47%), 113 at the lumbar levels (50.9%), and 68 at the sacral levels (30.36%). Flash was observed in 13 injections performed (5.85% of the total number of injections): one (0.45%) in the cervical, 2 (0.9%) in the lumbar, and 10 (4.5%) in the sacral levels. In 11 TFESI blood aspiration was obtained (4.95% of all injections): 3 (1.3%) in cervical, 4 (1.8%) in lumbar, and 4 (1.8%) in sacral injections. Live fluoroscopy during contrast injection detected 46 (20.72%) intravascular flow patterns: 7 (3.1%) cervical, 17 (7.6%) lumbar, and 22 (9.9%) sacral. DSA identified an additional 5 intravascular injections after all previous steps had resulted in negative vascular penetration signs, which accounted for 2.25% of all injections. Limitations: This is a prospective, single-center study with a relatively small number of patients and no control group. Conclusion: DSA detected additional 5.26% intravascular needle placements following traditional methods. Our findings also support other studies that conclude TFESI are generally a safe procedure. We recommend that special attention should be paid to the sacral injections as vascular penetration was statistically higher than at other levels. Key words: Digital subtraction angiography, transforaminal epidural steroid injections

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The A1-A2 Diameter Ratio May Influence Formation and Rupture Potential of Anterior Communicating Artery Aneurysms

Neurosurgery ◽

10.1227/neu.0000000000000125 ◽

2013 ◽

Vol 73 (5) ◽

pp. 845-853 ◽

Cited By ~ 12

Author(s):

Bruno C. Flores ◽

William W. Scott ◽

Christopher S. Eddleman ◽

H. Hunt Batjer ◽

Kim L. Rickert

Keyword(s):

Digital Subtraction Angiography ◽

Vascular Malformations ◽

Treatment Decision ◽

Control Group ◽

Anterior Communicating Artery ◽

Digital Subtraction ◽

Control Groups ◽

Posterior Circulation Aneurysms ◽

Group A ◽

Group B

Abstract BACKGROUND: Specific morphological factors contribute to the hemodynamics of the anterior communicating artery (AComA). No study has examined the role of the A2 segment on AComA aneurysm presence and rupture. OBJECTIVE: To examine the possibility that the ratio between A1 and A2 segments (A1-2 ratio) represents an independent risk factor for presence and rupture of AComA aneurysms (AComAAs). METHODS: A retrospective review of an institutional aneurysm database was performed; patients with ruptured and unruptured AComAAs were identified. Two control groups were selected: group A (posterior circulation aneurysms) and group B (patients without intracranial aneurysms or other vascular malformations). Measurements of A1 and A2 diameters were obtained from digital subtraction angiography (64.1% of 3-D rotational digital subtraction angiography), and the A1-2 ratio calculated. RESULTS: From January 2009 to April 2011, 156 patients were identified (52 AComAAs, 54 control group A, and 50 control group B). Mean age at the time of presentation was 56.09 years. Compared with both control groups, patients with AComAAs had greater A1 diameter (P < .01) and A1-2 ratio (P < .001) and smaller A2 diameter (P < .01). The A1-2 ratio correlated positively with the presence of AComAAs (P < .001). Ruptured AComAAs were smaller than unruptured ones (5.91 mm vs 9.25 mm, P = .02) and associated with a higher A1-2 Ratio (P = .02). The presence of a dominant A1 did not predict AComAA rupture (P = .15). The A1-2 ratio correlated positively with the presence of ruptured AComAAs (P = .04). CONCLUSION: A1-2 ratio correlates positively with the presence and rupture of AComAAs and may facilitate treatment decision in cases of small, unruptured AComAAs.

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Comparing the Mathematics Continuous Performance Test With Other Measures of Tests of Attention

European Journal of Psychological Assessment ◽

10.1027/1015-5759/a000261 ◽

2016 ◽

Vol 32 (4) ◽

pp. 291-297 ◽

Cited By ~ 1

Author(s):

Dubi Lufi ◽

Shachar Pan

Keyword(s):

Performance Test ◽

Continuous Performance Test ◽

Clinical Population ◽

Control Group ◽

Continuous Performance ◽

Adhd Assessment ◽

Research Reporting ◽

Hyperactivity Disorder ◽

Continuous Performance Tests ◽

Better Than

Abstract. Several studies have shown that Continuous Performance Tests (CPT) can diagnose Attention Deficit Hyperactivity Disorder (ADHD) better than other tests. Research reporting comparisons of two or more CPT-type tests is scarce. The purpose of the study was to compare the Mathematics Continuous Performance Test (MATH-CPT) with another CPT-type test (CPT II) and a questionnaire (the Brown Scale). The comparison was carried out by looking at correlations among subscales and checking the precision of detecting ADHD. Ninety-five high school and college students participated in the study, 41 with ADHD were the research group and 54 were the control group. The participants performed the two tests and answered the questionnaire. The results showed that the MATH-CPT correctly identified 74.50% of the participants of both groups as compared to the 71.60% of the CPT II. Correlations between the two CPT-type tests were moderate; however, they were similar to correlations found in other studies comparing similar tools. The MATH-CPT, final attention formula, showed significant correlations with the Brown scales, while the CPT II, confidence index associated with ADHD assessment, showed nonsignificant correlations with the questionnaire. The study indicated that MATH-CPT can be used with a clinical population of ADHD and for research purposes.

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