scholarly journals A novel three-dimensional volumetric method to measure indirect decompression after percutaneous cement discoplasty

2021 ◽  
Vol 28 ◽  
pp. 131-139
Author(s):  
Peter Endre Eltes ◽  
Laszlo Kiss ◽  
Ferenc Bereczki ◽  
Zsolt Szoverfi ◽  
Chloé Techens ◽  
...  
2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
E Tafciu ◽  
G Granata ◽  
F Ancona ◽  
S Stella ◽  
C Capogrosso ◽  
...  

Abstract Introduction Mitral regurgitation (MR) severity affects prognosis and a correct quantification is key for surgical indication. A multiparametric approach (MPA) is recommended, as singular parameters suffer pitfalls. Recently suggested three-dimensional echocardiographic (3DE) parameters lack clear reference values. No studies have assessed the feasibility of regurgitant volume (RV) and fraction (RF) using the 3D planimetric area of the mitral annulus (MAA) and of the left ventricular outflow tract (LVOTA). Purpose To assess the feasibility and reliability of 3DE, RV and RF obtained by doppler volumetric method using MAA and LVOTA, compare results with 2DE and 3D vena contracta area (VCA) and propose cut-offs for these parameters using MPA as gold standard. Methods Patients referred to our Department for MR assessment were enrolled from September 2018 to February 2019 without more than mild aortic regurgitation or severe stenosis, mitral stenosis and previous valvular surgery. Transthoracic 2DE was used to calculate a multiparametric index of MR severity including: jet area/left atrium (LA) area, CW characteristics, 2D vena contracta, PISA, pulmonary vein flow, LA volume and systolic pulmonary artery pressure. Transoesophageal 3DE was used to assess MAA and LVOTA from a 3D dataset. RV and RF were calculated by Doppler volumetric method using the planimetric areas instead of diameters. VCA 3D was calculated from a 3D color dataset as the cross-sectional area of the regurgitant jet. We compared the results between 2DE and 3DE and between functional and organic MR. ROC curves were analyzed to assess diagnostic performance and identify cut-offs for severity prediction. Intraclass correlation coefficient was calculated to assess variability in measurements. Results Population was composed by 87 patients (56 male, 65 ± 13 years), 72% organic MR. MAA was larger in 2DE (10.4 ± 3.2 vs 9.8 ± 2.9 cm2,) as was the RV (76.6 ± 36.1 vs 66.4 ± 31.9 ml) and RF (55.4 ± 12.4 vs 50.4 vs 10.9%, all p < 0.0001), while LVOTA was smaller (3.9 ± 0.98 vs 4.1 ± 1.0 cm2, p < 0.0001). RV 2D and RF 2D were larger in the organic MR group (p < 0.0001), meanwhile VCA 3D, RV 3D and RF 3D did not show a significant difference (all p > 0.1). VCA 3D had a good correlation with RV 3D (r = 0.593, p < 0.0001) and RF 3D (r = 0.576, p < 0.0001). We proposed a cut-off value of 41.5 mm2 for VCA 3D (94% sens, 96% spec, AUC 0.978), 52 ml for RV 3D (84% sens, 78% spec, AUC 0.901) and 47.6% for RF 3D (91% sens, 90% spec, AUC 0.966) to predict MR severity as assessed by MPA. Intraclass correlation coefficient was 0.980 for MAA and 0.985 for LVOTA for intra-observer variability, while for inter-observer variability it was 0.951 for MAA and 0.962 for LVOTA. Conclusion 2DE overestimates MA dimensions and underestimates LVOT dimensions thus overestimating RV and RF. 3DE measures are relatively simple and reproducible. Proposed cut-offs for RV, RF and VCA 3D have a good diagnostic power.


2020 ◽  
Vol 20 (1) ◽  
pp. E43-E43
Author(s):  
Michael J Strong ◽  
Siri Sahib S Khalsa ◽  
Timothy J Yee ◽  
Yamaan S Saadeh ◽  
Brandon W Smith ◽  
...  

Abstract Spondylolisthesis is a common cause of lower back and leg pain in adults. The initial treatment for patients is typically nonoperative in nature. However, when patients fail conservative management and their back and/or leg pain is recalcitrant, surgical intervention is warranted. Spinal decompression, either directly or indirectly, as well as fusion is often considered at this point. There are numerous approaches to fuse the spine, including anterior, lateral, or posterior, each with their own advantages and disadvantages.   This video illustrates a case of symptomatic spondylolisthesis occurring after laminectomy treated by lateral lumbar interbody fusion for indirect decompression and stabilization. The approach utilizes 3-dimensional navigation rather than traditional fluoroscopy, resulting in markedly decreased radiation exposure for the surgeon and staff while maintaining accuracy. Appropriate patient consent was obtained. This video demonstrates the technique for a lateral lumbar interbody fusion using navigation assistance, which is a minimally invasive technique for the treatment of spondylolisthesis.


2010 ◽  
Vol 36 (S1) ◽  
pp. 142-142
Author(s):  
M. G. Vizer ◽  
L. Pótó ◽  
G. Mátrai ◽  
T. Süle ◽  
J. Bódis ◽  
...  

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.


Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.


Author(s):  
P.L. Moore

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.


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