P2842Sequential application of horizontal and vertical orientation on radiofrequency ablation lesions produced by thermocool smarttouch SF catheter

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
K Morgaenko ◽  
S Noshin ◽  
W Stevenson ◽  
N Mehta
Keyword(s):  
Radiofrequency Ablation ◽  
Surface Area ◽  
Lesion Size ◽  
Ablation Catheter ◽  
Vertical Orientation ◽  
Lesion Depth ◽  
Catheter Design ◽  
Significant Difference ◽  
The Impact ◽  
Area And Volume

Abstract Background Ablation lesions represent a complex interaction between the ablation catheter configuration and tissue anatomy. An understanding of each variable can assist in determination of the optimal lesion set. One such variable is the catheter orientation. With an irrigated radiofrequency ablation catheter with 6 pores (6P) near the distal tip, lesion surface area and volumes are smaller in the horizontal catheter orientation compared to the vertical catheter orientation. This finding is explained by the 6P irrigation catheter design, where irrigation fluid is discharged from six ports around the circumference of the electrode. Introduced in 2015, the ThermoCool SmartTouch® SF catheter has a 56-pore (56P) distribution to provide high density low volume irrigation settings. Irrigation catheters create smaller lesions in horizontal orientation compared to vertical orientation, however this has not been studied for the 56P irrigated catheter. Purpose Evaluate the impact of catheter orientation with sequential application of 56P catheter. Methods Ablation lesions were created on additive-free chicken model in a saline bath heated to 37°C using the 56P catheter under standard flow rate (8cc/min) conditions. Ablation energy of 20W and 30W was delivered twice for 30 seconds with 3 minutes interval between applications. Contact force (CF) of 5, 10, 15, and 20g was applied with the following conditions: horizontal catheter orientation followed by horizontal (HH), vertical by vertical (VV), horizontal by vertical (HV), and vertical by horizontal catheter orientation (VH). Measurements were obtained by lesion dissection through the midpoint by 3 independent operators. Kruskal-Wallis test was used for comparison of lesion depth, surface area and volume. Results Ninety-six lesions were analyzed. No coagulum or steam pops were included in the analysis. The minimum and maximum lesion depth, surface area and volume were 1.5 & 6.0 mm, 14.1 & 117.7mm2, 47.1 & 471.0 mm3 respectively. There was no significant difference in the lesion depth, surface area or volume in HH, VV, HV or VH orientation at different CF with 20W and 30W. (Fig 1) Figure 1 Conclusion Unlike other irrigated catheters, catheter orientation with sequential application with different CF and power did not impact lesion depth, surface area and volume with 56P catheter. This finding could be considered useful in situations where the catheter orientation could be challenging owing to tissue anatomy to achieve adequate lesion size. Acknowledgement/Funding UVA Health System

scholarly journals Impact of a formula combining local impedance and conventional parameters on lesion size prediction

2021 ◽  
Author(s):  
Masateru Takigawa ◽  
Masahiko Goya ◽  
Hidehiro Iwakawa ◽  
Claire Martin ◽  
Tatsuhiko Anzai ◽  
...  
Keyword(s):  
Surface Area ◽  
Lesion Size ◽  
Contact Forces ◽  
Lesion Depth ◽  
Positive Correlation ◽  
Time Integral ◽  
Combined Indices ◽  
Force Time ◽  
Tissue Reactions ◽  
The Impact

Background: Although ablation energy (AE) and force-time integral (FTI) are well-known active predictors of lesion characteristics, these parameters do not reflect passive tissue reactions during ablation, which may instead be represented by drops in local impedance (LI). This study aimed to investigate if additional LI-data improves predicting lesion characteristics and steam-pops. Methods: RF applications at a range of powers (30W, 40W, and 50W), contact forces (8g, 15g, 25g, and 35g), and durations (10-180s) using perpendicular/parallel catheter orientations, were performed in excised porcine hearts (N=30). The correlation between AE, FTI and lesion characteristics was examined and the impact of LI (%LI-drop [%LID] defined by the ΔLI/Initial LI) was additionally assessed. Results: 375 lesions without steam-pops were examined. Ablation energy (W*s) and FTI (g*s) showed a positive correlation with lesion depth (ρ=0.824:P<0.0001 and ρ=0.708:P<0.0001), surface area (ρ=0.507:P<0.0001 and ρ=0.562:P<0.0001) and volume (ρ=0.807:P<0.0001 and ρ=0.685:P<0.0001). %LID also showed positive correlation individually with lesion depth (ρ=0.643:P<0.0001), surface area (ρ=0.547:P<0.0001) and volume (ρ=0.733, P<0.0001). However, the combined indices of AE*%LID and FTI*%LID provided significantly stronger correlation with lesion depth (ρ=0.834:P<0.0001 and ρ=0.809P<0.0001), surface area (ρ=0.529:P<0.0001 and ρ=0.656:P<0.0001) and volume (ρ=0.864:P<0.0001 and ρ=0.838:P<0.0001). This tendency was observed regardless of the catheter placement (parallel/perpendicular). AE (P=0.02) and %LID (P=0.002) independently remained as significant predictors to predict steam-pops (N=27). However, the AE*%LID did not increase the predictive power of steam-pops compared to the AE alone. Conclusion: LI, when combined with conventional parameters (AE and FTI), may provide stronger correlation with lesion characteristics.

scholarly journals Thermal and electric Characteristics of High-power Short-duration Radiofrequency Ablation and Standard Radiofrequency Ablation: A Computer Simulation Study

2021 ◽  
Author(s):  
Kaihao Gu ◽  
Shengjie Yan ◽  
Xiaomei Wu
Keyword(s):  
Radiofrequency Ablation ◽  
Short Duration ◽  
High Power ◽  
Lesion Size ◽  
Lesion Volume ◽  
Rf Ablation ◽  
Thermal Lesion ◽  
Lesion Depth ◽  
Lesion Diameter ◽  
Rate Of Increase

Abstract Background: High power-short duration ablation is an emerging conception for cardiac RF treatment. But the biophysical ablation properties of this technique have not been fully explored. This study compared the electric field characteristics and thermal lesion dimension in High power-short duration (HP-SD) radio frequency (RF) ablation and standard RF ablation by using the finite element method. Results: The results demonstrated that the lesion size and temperature in HP–SD RF ablation increased faster than standard RF ablation. The thermal lesion volume in both ablation modes demonstrated a linear increase and the rate of increase of HP–SD RF ablation grew faster than that of standard RF ablation. For HP–SD application at 50 W for 5 s, the lesion depth was shallower (1.74 to 2.1 mm vs 2.40 to 3.15 mm) and the surface lesion diameter was broader (2.76 to 3.32 mm vs 2.42 to 2.66 mm) than that for standard RF ablation at 25 W for 30 s. Conclusion: Compared with standard RF ablation, HP–SD RF ablation creates a broader lesion width and surface lesion diameter but shallower lesion depth, with a faster increase in temperature. HP–SD ablation is more able to achieve uniform and contiguous lesion shape, which is a suitable for point-to-point RF ablation procedures.Higher temperature was formed in deeper space of cardiac tissue in HP–SD ablation. The duration of HP–SD ablation should be strictly controlled for preventing the steam occur in tissue.

scholarly journals Patient and clinician satisfaction and clinical outcomes of Magseed compared with wire-guided localisation for impalpable breast lesions

Breast Cancer ◽  
2020 ◽  
Author(s):  
Aikaterini E. Micha ◽  
Victoria Sinnett ◽  
Kate Downey ◽  
Steve Allen ◽  
Briony Bishop ◽  
...  
Keyword(s):  
Guide Wire ◽  
Positive Margin ◽  
Lesion Size ◽  
Ease Of Use ◽  
Breast Lesions ◽  
Continuous Variables ◽  
Patient Anxiety ◽  
Significant Difference ◽  
Clinician Satisfaction ◽  
The Impact

Abstract Background Guide-wire localisation remains the most commonly used technique for localisation of impalpable breast lesions in the UK. One alternative is magnetic seed localisation. We aimed to investigate patient and clinician satisfaction in two consecutive cohorts, describe re-excision and positive margin rates, and explore reasons for positive margins and the implications for localisation techniques. Methods A single-institution prospective service evaluation of two cohorts of consecutive cases of wire and then Magseed localisation was carried out. Data were collected on patient and clinician satisfaction, clinico-pathological findings, and causes of involved margins. T tests were used to compare continuous variables and Chi-squared test for satisfaction outcomes. Results 168 consecutive cases used wire-guided localisation (WGL) and 128 subsequent cases used Magseeds. Patients reported less anxiety between localisation and surgery in the Magseed group, and clinicians reported greater ease of use of Magseeds. There were no differences in lesion size, surgical complexity, or re-excision rate between the groups. In a subset of patients receiving standard wide local excision (i.e., excluding mammoplasties), the impact on margin involvement was investigated. There was no significant difference in radiological under-sizing or accuracy of localisation. However, specimen weight and eccentricity of the lesion were statistically significantly lower in the Magseed group. Despite this, re-excision rates were not significantly different (p = 0.4). Conclusions This is the first large study of satisfaction with localisation and showed clinician preference for Magseed and a reduction in patient anxiety. It also demonstrated similar positive margin rates despite smaller specimen weights in the Magseed group. Magnetic seed localisation offers an acceptable clinical alternative to guide wire localisation. The impact on local service provision should also be considered.

scholarly journals Novel Contact Force Sensor Incorporated in Irrigated Radiofrequency Ablation Catheter Predicts Lesion Size and Incidence of Steam Pop and Thrombus

2008 ◽  
Vol 1 (5) ◽  
pp. 354-362 ◽  
Author(s):  
Katsuaki Yokoyama ◽  
Hiroshi Nakagawa ◽  
Dipen C. Shah ◽  
Hendrik Lambert ◽  
Giovanni Leo ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Contact Force ◽  
Force Sensor ◽  
Lesion Size ◽  
Ablation Catheter

scholarly journals Early childhood deprivation is associated with alterations in adult brain structure despite subsequent environmental enrichment

2020 ◽  
Vol 117 (1) ◽  
pp. 641-649 ◽  
Author(s):  
Nuria K. Mackes ◽  
Dennis Golm ◽  
Sagari Sarkar ◽  
Robert Kumsta ◽  
Michael Rutter ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Early Childhood ◽  
Surface Area ◽  
Attention Deficit ◽  
Brain Structure ◽  
Adult Brain ◽  
Hyperactivity Disorder ◽  
The Impact ◽  
Childhood Deprivation ◽  
Area And Volume

Early childhood deprivation is associated with higher rates of neurodevelopmental and mental disorders in adulthood. The impact of childhood deprivation on the adult brain and the extent to which structural changes underpin these effects are currently unknown. To investigate these questions, we utilized MRI data collected from young adults who were exposed to severe deprivation in early childhood in the Romanian orphanages of the Ceaușescu era and then, subsequently adopted by UK families; 67 Romanian adoptees (with between 3 and 41 mo of deprivation) were compared with 21 nondeprived UK adoptees. Romanian adoptees had substantially smaller total brain volumes (TBVs) than nondeprived adoptees (8.6% reduction), and TBV was strongly negatively associated with deprivation duration. This effect persisted after covarying for potential environmental and genetic confounds. In whole-brain analyses, deprived adoptees showed lower right inferior frontal surface area and volume but greater right inferior temporal lobe thickness, surface area, and volume than the nondeprived adoptees. Right medial prefrontal volume and surface area were positively associated with deprivation duration. No deprivation-related effects were observed in limbic regions. Global reductions in TBV statistically mediated the observed relationship between institutionalization and both lower intelligence quotient (IQ) and higher levels of attention deficit/hyperactivity disorder symptoms. The deprivation-related increase in right inferior temporal volume seemed to be compensatory, as it was associated with lower levels of attention deficit/hyperactivity disorder symptoms. We provide compelling evidence that time-limited severe deprivation in the first years of life is related to alterations in adult brain structure, despite extended enrichment in adoptive homes in the intervening years.

scholarly journals Catheter contact angle influences local impedance drop during radiofrequency catheter ablation: insight from a porcine experimental study

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
G Matsuura ◽  
H Fukaya ◽  
E Ogawa ◽  
S Kawakami ◽  
D Saito ◽  
...  
Keyword(s):  
Experimental Study ◽  
Contact Angle ◽  
Catheter Ablation ◽  
Radiofrequency Catheter Ablation ◽  
Lesion Size ◽  
Contact Angles ◽  
Tissue Temperature ◽  
Ablation Catheter ◽  
Lesion Depth ◽  
The Difference

Abstract Background Local impedance (LI) at a distal tip of the ablation catheter can indirectly measure catheter contact and tissue temperature during radiofrequency catheter ablation (RFCA). LI decreases by RFCA, and a degree of LI drop is correlated with lesion size. However, data on the effects of catheter contact angle on lesion size and LI drop were scarce. This study aimed to evaluate the influence of catheter contact angle on lesion size and LI drop in a porcine experimental study. Methods Lesions were created on porcine myocardial left ventricles by the LI-sensing ablation catheter (IntellaNav MiFi OI®). Contact force (CF) was measured using pressure to current transducer (load cell). Radiofrequency ablation was performed with a power of 30 Watt and a duration of 30 seconds. CF (0g, 5g, 10g, 20g, and 30g) and catheter angle (30°, 45°, and 90°) were changed in each set (total 120 lesions, n=8 each). LI rise, LI drop by RF application, and lesion size (maximum lesion width, maximum surface width, and maximum lesion depth) were evaluated. Results There was no angular dependence in LI rise in all CF. The values of LI rise increased as CF increased. The LI drop also increased as CF increased in all contact angles. Regarding the difference of catheter angles, LI drop with 90° was lower than those with 30° and 45°in CF 10g, 20g, and 30g, respectively. Maximum lesion width and surface width were larger in 30° and 45° than those in 90°, whereas there were no differences in maximum lesion depth. Conclusion LI drop in 90° were significantly lower than those in 45° and 30°. Although lesion depths were not different among the three angles, the absolute values of LI drop were different. Caution should be exercised to comprehend the LI drop with catheter angles. FUNDunding Acknowledgement Type of funding sources: None.

Effects of Open-Irrigated Radiofrequency Ablation Catheter Design on Lesion Formation and Complications: In Vitro Comparison of 6 Different Devices

2013 ◽  
Vol 24 (10) ◽  
pp. 1157-1162 ◽  
Author(s):  
JOSE M. GUERRA ◽  
ESTHER JORGE ◽  
SILVIA RAGA ◽  
CAROLINA GÁLVEZ-MONTÓN ◽  
CONCEPCIÓN ALONSO-MARTÍN ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Ablation Catheter ◽  
Lesion Formation ◽  
Catheter Design ◽  
In Vitro Comparison

Abstract 303: Optical Tissue Interrogation Technology Incorporated in Irrigated Radiofrequency Ablation Provides Real Time Monitoring of Ablation Lesion Depth

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Talal Alzahrani ◽  
Mohammed Aljishi ◽  
Marco Mercader
Keyword(s):  
Radiofrequency Ablation ◽  
Real Time ◽  
Correlation Coefficient ◽  
Signal Intensity ◽  
Tissue Characterization ◽  
Lesion Size ◽  
Ablation Lesion ◽  
Success Rates ◽  
Tetrazolium Chloride ◽  
Lesion Depth

Background: Radiofrequency ablation (RFA) is an effective therapy to treat cardiac arrhythmias. The success rate depends on the location and size of ablation lesions. Electroanatomic Mapping and Contact force-sensing catheters have been shown to enhance the success rates of RFA. We used real-time optical tissue interrogation within the NADH fluorescence (fNADH) range to assess the progression of ablation lesion depth in real time during RF delivery (LuxCath catheter). Methods: Multiple RFA lesions (n=20) were made on an intubated and mechanically ventilated canine (Mongrel) thigh muscles using 7 Fr quadripolar RFA catheter with a 3.5 mm tip open 3.5 mm irrigated electrode incorporating imaging optic. Light was delivered at (360+/-25nm), and fluorescence acquired through fiberoptic bundle at (370-660 nm) by a spectrometer and analyzed in real time. Two types of plots were created for each lesion: intensity (in counts) vs. wavelength (nm), and 465nm peak amplitude (normalized) vs. time (sec). The lesions were made at room temperature with fixed power (15W) and four different durations (10, 20,30,40 sec). After ablation the muscle was stained with 2,3,4-triphenyl-2H-tetrazolium chloride (TTC), bisected at the center and measured the with and depth of the lesion using imageJ software. Results: We performed a total of twenty lesions that were divided into four groups based on the duration of the ablation (10, 20, 30, 40 seconds). The mean lesion depth for those groups was 4.05+/-1.28, 4.99+/-0.9, 6.9+/-1.06 and 7.14+/-1.41 mm, respectively. Lesion depth was correlated with the duration of ablation and fNADH signal intensity with a correlation coefficient of 0.93 and 0.99, respectively. Finally, there was a significant correlation between lesion size and fNADH signal intensity with a correlation coefficient of 0.96. Conclusion: Real-time optical tissue characterization can provide an excellent assessment of lesion progression during RF delivery. Lesion depth was directly correlated to the decrease in fNADH signal intensity. This information may be used to optimize the selection of RF power and RF application time to maximize RF lesion formation and improve the success of ablation procedures.

scholarly journals AN INVESTIGATION OF THE SURGICAL ANATOMY OF THE PEDIATRIC ILIOTIBIAL BAND

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0010
Author(s):  
Philip L. Wilson ◽  
Henry B. Ellis ◽  
Connor G. Richmond ◽  
Meagan J. Sabatino ◽  
Charles W. Wyatt ◽  
...  
Keyword(s):  
Surface Area ◽  
Age Groups ◽  
Surgical Anatomy ◽  
Iliotibial Band ◽  
Anatomical Landmarks ◽  
Significant Difference ◽  
Group 2 ◽  
The Impact ◽  
Gerdy’S Tubercle ◽  
Group 1

Background: Previous work on adult specimens have demonstrated some differential thickness of the iliotibial band (ITB) tissue in different areas. The purpose of this study was twofold: 1) to quantitatively and qualitatively describe the relevant surgical anatomy of the ITB, at the level of the knee, in pediatric cadaveric specimens in which either an iliotibial band tenodesis or extraphyseal reconstruction would be considered, and 2) to provide recommendations that allow the surgeon to obtain the ideal graft in terms of tissue width and location on the larger ITB structure. Methods: Pediatric cadaveric specimens (n=24) were dissected by a group of fellowship trained pediatric orthopaedic surgeons. Digital photography of each specimen was obtained prior to collecting quantitative data of the ITB and its three main divisions using digital calipers and a coordinated measurement device (Hexagon Romer Absolute V3 CMM). Measurements included thickness, surface area, length, and width of each branch; surface area and length of each insertion; and distance of insertion in relation to other pertinent anatomical landmarks. Specimens were grouped into four age groups (Group 1: 2 year olds, Group 2: 3 and 4 year olds, Group 3: 5-7 year olds, and Group 4: 9-11 year olds). The four age groups were compared utilizing ANOVA and nonparametric Kruskal-Wallis tests with post-hoc analysis using the Tukey method. In order to correlate measurements and age, a Spearman’s correlation was used. Results: All specimens (mean age 4.7 years; range 2-11) contained a visible ITB with a direct primary arm to Gerdy’s tubercle. Sixteen specimens (66.6%) had a visible trifurcation point, in which the aggregate of ITB fibers diverge into three distinct branches: a direct arm, the iliopatellar branch, and the iliotendinous branch (Figure 1). Fibers from the central third of the iliotibial band, as described as the primary site for harvest, do not terminate on Gerdy’s tubercle, but diverge to the patella, patellar tendon and a portion of Gerdy’s tubercle. The length from the trifurcation point to the insertion of the direct arm at Gerdy’s tubercle increased with each age group (21.3 mm, 29.9 mm, 31.5 mm, and 41.8 mm, respectively) with a significant difference seen between Group 1 and 4 (p<0.01) and Group 2 and 4 (p=0.03), indicating migration of this point with longitudinal growth. The mean thicknesses of the direct arm (0.55 mm), the iliopatellar branch (0.74 mm), and iliotendinous branch (0.42 mm) were not statistically different between age groups. Length, width, and surface area were also not statistically different between age groups. Conclusion: The ITB is a consistent, well-defined structure in pediatric specimens. While some longitudinal changes in the ITB and its insertions were seen with increasing age, the thickness and width of the direct arm of the ITB, typically harvested for extra-physeal ACL reconstruction, does not appear to differ between age groups and does not represent the thickest distal branch of the ITB. The location of ITB harvest may influence the impact that the extra-articular “capsular tightening” has on joint mechanics, including altering the compression across the joint, and/or the impact on the Pivot-Shift/rational laxity of the knee undergoing ITB reconstructions. Further study of the graft location/harvest and its impact on knee biomechanics is warranted. [Figure: see text]

scholarly journals Feed intake in Atlantic salmon fed with or without surface spreading of feed

2020 ◽  
Vol 25 ◽  
pp. 20
Author(s):  
Turid Synnøve Aas ◽  
Trine Ytrestøyl ◽  
Torbjørn Åsgård ◽  
Kristoffer Rist Skøien ◽  
Morten Omholt Alver ◽  
...  
Keyword(s):  
Body Weight ◽  
Atlantic Salmon ◽  
Surface Area ◽  
Feed Intake ◽  
Sea Water ◽  
Competitive Behavior ◽  
Significant Difference ◽  
Final Weight ◽  
The Impact ◽  
Surface Spreading

In intensive salmon farming, it is common practice to spread the feed over a large surface area, assuming that spreading of the feed increases feed intake in the fish. However, the impact on the feed pellets during spreading results in feed loss due to pellet breakage. In this study, feed intake, growth and signs of aggressive behavior was compared in salmon fed without or with spreading of the feed on the surface area of the tanks. Atlantic salmon (Salmo salar) with initial body weight 0.6 kg were kept in 3.3 m 3 tanks supplied with sea water (salinity 32 %, mean temperature 11 °C) for one month. The salmon were fed one meal daily, either by dropping the feed from one point, or by spreading the feed over the water surface. Feed intake and growth was measured. Fin damage was given a score at termination of the trial as a measure of competitive behavior during feeding. The relative feed intake (i.e. percent of body weight per day) in salmon fed without spreading or with spreading of the feed was 0.63±0.05 and 0.64±0.02 %, respectively. The growth rate was identical in salmon fed without or with spreading of the feed, and no significant difference in variance in final weight was found. No difference in fin damage for salmon fed without or with spreading of the feed was revealed. The data showed that for the conditions used in this trial, spreading of feed had no influence on feed intake or growth of salmon.

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