scholarly journals Hemodynamic changes in superficial arteriovenous malformation surgery measured by intraoperative ICG fluorescence videoangiography with FLOW 800 software

2020 ◽  
Author(s):  
Xun Ye ◽  
Liang Wang ◽  
Ming-tao Li ◽  
Xiao-lin Chen ◽  
Hao Wang ◽  
...  
Keyword(s):  
Arteriovenous Malformation ◽  
Hemodynamic Parameter ◽  
Maximum Intensity ◽  
Parameter Analysis ◽  
Hemodynamic Parameters ◽  
Hemodynamic Changes ◽  
Transit Times ◽  
Local Cycle ◽  
Flow 800

Abstract Background: Arteriovenous malformation(AVM) have long-term “blood stealing” characteristics, which result in complicated hemodynamic features. To analyze the application of intraoperative indocyanine green angiography with FLOW 800 software in AVM surgeries.Methods: Data on 17 patients undergoing surgery with ICG fluorescence were collected. To analyze the hemodynamic features of AVM and the influence on the peripheral cortex of AVM resection, we assessed the following hemodynamic parameters: maximum intensity, slope of rise, time to half-maximal fluorescence, and transit time from arteries to veins.Results：In the 17 superficial AVMs studied, the time delay color mode of FLOW 800 software was superior to the traditional playback mode for identifying feeding arteries, draining veins, and their relation to normal cortical vessels.The maximum fluorescence intensity and slope of the ICG fluorescence curve of feeder arteries and draining veins were higher than those of normal peripheral vessels (P < 0.05). The transit times in AVMs were significantly shorter than those in normal peripheral vessels (P < 0.05).After AVM resection, cerebral flow increased in the cortex, and local cycle time become longer, although the differences were not significant (P > 0.05).Conclusions:Hemodynamic parameter analysis provided quality guidance for the resection of AVMs and could also be used in estimating changes in blood flow in the local cortex to identify abnormal hyperperfusion and residual nidus.

scholarly journals Hemodynamic changes in superficial arteriovenous malformation surgery measured by intraoperative ICG fluorescence videoangiography with FLOW 800 software

2020 ◽  
Author(s):  
Xun Ye ◽  
Liang Wang ◽  
Ming-tao Li ◽  
Xiao-lin Chen ◽  
Hao Wang ◽  
...  
Keyword(s):  
Arteriovenous Malformation ◽  
Hemodynamic Parameter ◽  
Maximum Intensity ◽  
Parameter Analysis ◽  
Hemodynamic Parameters ◽  
Hemodynamic Changes ◽  
Transit Times ◽  
Icg Angiography ◽  
Local Cycle ◽  
Flow 800

Abstract To analyze the application of intraoperative indocyanine green (ICG) angiography with FLOW 800 software in arteriovenous malformation (AVM) surgeries. Data on 17 patients undergoing surgery with ICG fluorescence were collected. To analyze the hemodynamic features of AVM and the influence on the peripheral cortex of AVM resection, we assessed the following hemodynamic parameters: maximum intensity, slope of rise, time to half-maximal fluorescence, and transit time from arteries to veins. In the 17 superficial AVMs studied, the time delay color mode of FLOW 800 software was superior to the traditional playback mode for identifying feeding arteries, draining veins, and their relation to normal cortical vessels.The maximum fluorescence intensity and slope of the ICG fluorescence curve of feeder arteries and draining veins were higher than those of normal peripheral vessels (P < 0.05). The transit times in AVMs were significantly shorter than those in normal peripheral vessels (P < 0.05).After AVM resection, cerebral flow increased in the cortex, and local cycle time become longer, although the differences were not significant (P > 0.05). Hemodynamic parameter analysis provided quality guidance for the resection of AVMs and could also be used in estimating changes in blood flow in the local cortex to identify abnormal hyperperfusion and residual nidus.

scholarly journals FLOW 800 Allows Visualization of Hemodynamic Changes After Extracranial-to-Intracranial Bypass Surgery but Not Assessment of Quantitative Perfusion or Flow

2013 ◽  
Vol 10 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Vincent Prinz ◽  
Nils Hecht ◽  
Naoki Kato ◽  
Peter Vajkoczy
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Superficial Temporal Artery ◽  
Laser Speckle ◽  
Flow Index ◽  
Bypass Grafting ◽  
Hemodynamic Parameters ◽  
Hemodynamic Changes ◽  
Blood Flow Index ◽  
Flow 800

Abstract BACKGROUND: FLOW 800 delivers a color-coded map for snapshot visualization of the temporal distribution dynamics after indocyanine green angiography with post hoc calculation of FLOW 800-specific hemodynamic parameters. However, the value of these parameters regarding quantitative flow assessment remains unclear. OBJECTIVE: To determine the value of FLOW 800-specific hemodynamic parameters in neurosurgical patients that permit assessment of hemodynamic changes within the microcirculation and macrocirculation. METHODS: FLOW 800 was performed in 25 patients undergoing superficial temporal artery to middle cerebral artery bypass grafting and in 5 patients undergoing high- or intermediate-flow bypass grafting. The time to half-maximum fluorescence (t1/2max) and the cerebral blood flow index were calculated in the recipient vessel (macrocirculation) and the cortical territory (microcirculation) surrounding the anastomosis. For further evaluation, FLOW 800-specific hemodynamic parameters were compared with cortical laser speckle imaging and quantitative Doppler flow within the graft. RESULTS: FLOW 800 provided color-coded information on the temporospatial distribution dynamics of the dye with excellent assessment of bypass patency. In the recipient vessel and in the cortical territory surrounding the anastomosis, FLOW 800 detected hemodynamic changes after superficial temporal artery to middle cerebral artery bypass grafting in terms of a significant decrease in t1/2max and increase in cerebral blood flow index. Interestingly, comparison of t1/2max with semiquantitative laser speckle imaging-specific cortical perfusion within the microcirculation demonstrated poor agreement, and neither t1/2max nor the cerebral blood flow index within the graft correlated with quantitative graft flow assessed by Doppler. CONCLUSION: FLOW 800 may detect procedure-related hemodynamic changes within the microcirculation and macrocirculation but should not be used as a stand-alone tool for quantitative flow assessment.

Hydrogeological responses in tropical mountainous springs

2019 ◽  
Author(s):  
Ricardo Sánchez-Murillo
Keyword(s):  
Costa Rica ◽  
Isotope Composition ◽  
Central Valley ◽  
Distribution Functions ◽  
Geochemical Composition ◽  
Transit Times ◽  
Management Plans ◽  
Best Fit ◽  
Term Data

This study presents a hydrogeochemical analysis of spring responses (2013-2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2H in rainfall resulted in a highly significant meteoric water line: δ2H = 7.93×δ18O + 10.37 (r2=0.97). Rainfall isotope composition exhibited a strong dependent seasonality. The isotopic variation (δ18O) of two springs within the Barva aquifer was simulated using the FlowPC program to determine mean transit times (MTTs). Exponential-piston and dispersion distribution functions provided the best-fit to the observed isotopic composition at Flores and Sacramento springs, respectively. MTTs corresponded to 1.23±0.03 (Sacramento) and 1.42±0.04 (Flores) years. The greater MTT was represented by a homogeneous geochemical composition at Flores, whereas the smaller MTT at Sacramento is reflected in a more variable geochemical response. The results may be used to enhance modelling efforts in central Costa Rica, whereby scarcity of long-term data limits water resources management plans.

The Spread of Pollutants from Harbour Sludge Depots

1984 ◽  
Vol 16 (3-4) ◽  
pp. 623-633
Author(s):  
M Loxham ◽  
F Weststrate
Keyword(s):  
Time Scales ◽  
Molecular Diffusion ◽  
Near Field ◽  
Parameter Analysis ◽  
Migration Patterns ◽  
Long Time ◽  
Dilution Effects ◽  
Short Time ◽  
Harbour Sludge

It is generally agreed that both the landfill option, or the civil techniques option for the final disposal of contaminated harbour sludge involves the isolation of the sludge from the environment. For short time scales, engineered barriers such as a bentonite screen, plastic sheets, pumping strategies etc. can be used. However for long time scales the effectiveness of such measures cannot be counted upon. It is thus necessary to be able to predict the long term environmenttal spread of contaminants from a mature landfill. A model is presented that considers diffusion and adsorption in the landfill site and convection and adsorption in the underlaying aquifer. From a parameter analysis starting form practical values it is shown that the adsorption behaviour and the molecular diffusion coefficient of the sludge, are the key parameters involved in the near field. The dilution effects of the far field migration patterns are also illustrated.

scholarly journals Sensitivity of hemodynamic parameters obtained by conventional duplex scanner in the evaluation of extracranial carotid disease severity

2003 ◽  
Vol 60 (4) ◽  
pp. 435-442
Author(s):  
Gordana Arandjelovic-Minic
Keyword(s):  
Spectral Analysis ◽  
Carotid Stenosis ◽  
Doppler Ultrasonography ◽  
Screening Method ◽  
Statistical Processing ◽  
Mean Value ◽  
Hemodynamic Parameter ◽  
Hemodynamic Parameters ◽  
Carotid Disease ◽  
Significant Independent Predictor

Progresson of extracranial carotid disease is considered to be significant independent predictor in the evaluation of individual cerebrovascular prognosis. Doppler ultrasonography is a useful screening method in the diagnosis and evaluation of extracranial carotid disease. The aim of this study was to establish the most sensitive hemodynamic parameter of Doppler-ultrasonographic spectral analysis in clinical evaluation of extracranial carotid disease. Investigation included 90 patients (of both sexes) in hospital and outpatient clinic care. Spectral analysis (M-scanning technique) was used for the evaluation of hemodynamic status of carotid sinus, including the following parameters: Pourcelot (A-D/A), Gosling (A/B) and Mol (A/D) resistance parameters. After statistical processing the results of the research affirmed hemodynamic parameters' values and correlation between Pourcelot hemodynamic parameter and the degree of carotid stenosis ?=0,59 for all patients, and ?=0,58 for patients with pathological values. Correlation between Mol parameter and the degree of carotid stenosis was ?=0,50 for all patients, and ?=0,57 for patients with pathological values. Gosling parameter was not significantly different in mean value and was present in all three groups. Functional relationship between the degree of carotid stenosis and each of hemodynamic parameters was established. It was concluded that Pourcelot and Mol parameters were significant indicators of asimptomatic carotid disease, but Pourcelot parameter was considered as a more sensitive indicator in the evaluation of extracranial carotid disease.

scholarly journals Results of Hemodynamic Correction in Patients with Double Outlet Right Ventricle

2019 ◽  
pp. 55-60
Author(s):  
Kh. K. Abralov ◽  
O. Kh. Karimov ◽  
S. O. Siromakha ◽  
I. V. Dziuriy ◽  
Ya. P. Truba ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Tricuspid Valve ◽  
Double Outlet Right Ventricle ◽  
Outflow Tract ◽  
Hemodynamic Parameters ◽  
Mixed Form ◽  
Cavopulmonary Anastomosis ◽  
Common Ventricle ◽  
The Common

Aim. To analyze results of hemodynamic correction in surgical treatment of double outlet right ventricle (DORV). Маterials and methods. For the period from January 1996 to September 2017, 31 (6.03 % of total number of patients with DORV) patients underwent hemodynamic correction of DORV. The age of the patients ranged from 1 to 19 years (71.2 ± 50.5 months on the average). The weight of the patients ranged from 9 to 41 kg (19.6 ± 11.3 kg on the average). Of these, 19 (61.3 %) were male patients and 12 (38.7 %) were female patients. The overwhelming majority (25 (80.6 %)) of the patients were diagnosed with transposition-type DORV. The anatomy of DORV with non-committed ventricular septal defect was observed in 5 (16.1 %) patients. In one patient (3.1 %), the anatomy of DORV (in the form of tetralogy of Fallot) was combined with tricuspid valve atresia. Results. The main reasons of hemodynamic correction in 16 (51.6 %) cases was LV hypoplasia. In 2 cases it was combined with tricuspid valve (TV) straddling, and in 2 cases it was an integral part of the unbalanced form of complete atrio-ventricular communication (AVC). In one case (3.1 %), the unbalanced form of complete AVC was combined with a mixed form of the common ventricle. The mixed form of the common ventricle was the reason of hemodynamic correction in 9 (29 %) patients. In 2 (6.2 %) cases, hemodynamic correction was performed due to the anatomy of the RV hypoplasia. In the remaining 2 patients, anatomy of the common ventricle was not diagnosed, but a combination of other concomitant defects was a contraindication to biventricular correction. Palliative operations (Blalock-Taussig shunt, BTS) as the first stage of correction were performed in 16 (51.6 %) patients. In 2 patients with LV outflow tract obstruction, systemic-pulmonary anastomosis was applied in combination with plastic repair of the great vessel roots using the proprietary technique for elimination of the left ventricular outflow tract (LVOT) stenosis. Bidirectional cavopulmonary anastomosis (BCPA) was applied in 29 (93.5 %) cases. Of these, 4 (13.8 %) patients subsequently underwent total cavopulmonary anastomosis (TCPA) procedure. Two patients with good hemodynamic parameters underwent TCPA without prior palliative procedures. Conclusion. Palliative surgery as the first stage to hemodynamic correction is accompanied by significant improvement in hemodynamic parameters of patients. Application of BCPA as the second stage of hemodynamic correction provides good results and is required to prepare the patient for TCPA. The long-term period is characterized by improvement in the quality of life in patients with complex DORV. In the long-term period, 85.2 % of patients are classified as NYHA FC I.

scholarly journals Perioperative Hemodynamic Changes During Video-Assisted Thoracoscopic Decortication for empyema

2017 ◽  
Vol 11 (1) ◽  
pp. 88-96
Author(s):  
Fang-Ting Chen ◽  
An-Hsun Chou ◽  
Chun-Yu Chen ◽  
Pei-Chi Ting ◽  
Ming-Wen Yang ◽  
...  
Keyword(s):  
Lung Ventilation ◽  
Lateral Decubitus Position ◽  
Time Interval ◽  
Hemodynamic Parameters ◽  
Hemodynamic Changes ◽  
Video Assisted ◽  
Lateral Decubitus ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Background and Objective: Hemodynamic consequences during video-assisted thoracoscopic surgery (VATS) with decortication during empyema drainage are unclear. The aim of the study was to assess the perioperative hemodynamic changes decortication during empyema drainage. Methods: A prospective study enrolled 23 patients with empyema who underwent decortication. Hemodynamic parameters were continuously obtained at 15 time points: supine two lung ventilation after induction, lateral decubitus position and two lung ventilation, lateral decubitus position and one-lung ventilation, every 5 min after decortication upto 60 minutes and at the end of surgery. We divided patients into three groups according to microorganisms, group 1: patients with no growth of organism; group 2: patients with staphylococcus aureus and pseudomonas; group 3: patients with streptococcus, yeast and fungus, gram-positive bacilli, and mycobacterium tuberculosis. The hemodynamic variables were recorded by the third-generation Vigileo/FloTracTM system and variables for each time interval were compared with the baseline by Wilcoxon Signed Ranks Test. Results: In group 1, hemodynamic parameters showed no significant changes over time. However, in group 2 and 3, both CO and CI increased 10 to 15 minutes after decortication and remained elevated during the remainder of surgery. However, SVR and SVRI decreased 10 to 15 minutes after decortication in both groups, especially, with a more significant decrease noted in group 2 than group 3. Conclusion: Close perioperative hemodynamic monitoring during decortication in empyema patients is required because of potential hemodynamic disturbances especially patients with toxic microorganisms.

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