PURPOSE: To demonstrate the feasibility of irreversible electroporation (IRE) for treating biliary metal stent occlusion in an experimental liver model. METHODS AND MATERIALS: IRE was performed using an expandable tubular IRE-catheter placed in nitinol stents in the porcine liver. A 3-electrode IRE-catheter was connected to an IRE-generator and one hundred 100μs pulses of constant voltage (300, 650, 1000, and 1300 V) were applied. Stent occlusion was simulated by insertion of liver tissue both ex vivo (n = 94) and in vivo in 3 pigs (n = 14). Three scenarios of the relationship between the stent, electrodes, and inserted tissue (double contact, single contact, and stent mesh contact) were studied. Electric current was measured and resistance and power calculated. Pigs were sacrificed 72 h post-procedure. Harvested samples (14 experimental, 13 controls) underwent histopathological analysis. RESULTS: IRE application was feasible at 300 and 650 V for the single and double contact setup in both ex vivo and in vivo studies. Significant differences in calculated resistance between double contact and single contact settings were observed (ex-vivo p ˂ 0.0001, in-vivo p = 0.02; Mann-Whitney). A mild temperature increase of the surrounding liver parenchyma was noted with increasing voltage (0.9-5.9 °C for 300-1000 V). The extent of necrotic changes in experimental samples in vivo correlated with the measured electric current (r2 = 0.39, p = 0.01). No complications were observed during or after the in-vivo procedure. CONCLUSION: Endoluminal IRE using an expandable tubular catheter in simulated metal stent occlusion is feasible. The relationship of active catheter electrodes to stent ingrowth tissue can be estimated based on resistance values.
- MeSH
- ablace * MeSH
- elektroporace * MeSH
- katétry MeSH
- prasata MeSH
- stenty MeSH
- teoretické modely MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Robust voxelwise analysis using tract-based spatial statistics (TBSS) together with permutation statistical method is standardly used in analyzing diffusion tensor imaging (DTI) of brain. A similar analytical method could be useful when studying DTI of cervical spinal cord. Based on anatomical data of sixty-four healthy volunteers, white (WM) and gray matter (GM) masks were created and subsequently registered into DTI space. Using TBSS, two skeleton types were created (single line and dilated for WM as well as GM). From anatomical data, percentage rates of overlap were calculated for all skeletons in relation to WM and GM masks. Voxelwise analysis of fractional anisotropy values depending on age and sex was conducted. Correlation of fraction anisotropy values with age of subjects was also evaluated. The two WM skeleton types showed a high overlap rate with WM masks (~94%); GM skeletons showed lower rates (56% and 42%, respectively, for single line and dilated). WM and GM areas where fraction anisotropy values differ between sexes were identified (p < .05). Furthermore, using voxelwise analysis such WM voxels were identified where fraction anisotropy values differ depending on age (p < .05) and in these voxels linear dependence of fraction anisotropy and age (r = -0.57, p < .001) was confirmed by regression analysis. This dependence was not proven when using WM anatomical masks (r = -0.21, p = .10). The analytical approach presented shown to be useful for group analysis of DTI data for cervical spinal cord.
- MeSH
- algoritmy * MeSH
- anizotropie MeSH
- bílá hmota diagnostické zobrazování MeSH
- difuzní magnetická rezonance * MeSH
- dospělí MeSH
- krční mícha diagnostické zobrazování MeSH
- lidé středního věku MeSH
- lidé MeSH
- počítačové zpracování obrazu metody MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVE: Surgical resection of a part of the intestine is a standard procedure in gastrointestinal surgery and in order to perform this type of surgery successfully, tissue blood flow must be evaluated clearly. There exists a theoretical indication that it would be possible to use infrared thermography (IRT) for this purpose. Therefore, the main objective of the study is the qualitative evaluation of the infrared thermography method as an ancillary method for determining the resection lines and forming an optimal intestinal anastomosis on the porcine model. APPROACH: Blood circulation rate has a close relationship with temperature difference and is also very important for identifying the resection lines on the bowel, the formation of anastomoses, and, subsequently, their adequate healing. Therefore, IRT could be helpful in determining the nonvascular part of the intestine. In order to make a qualitative evaluation of this method, the study also focuses on a comparison of IRT with the contrasting indocyanine green (ICG) imaging method, which is commonly used. MAIN RESULTS: The comparison of two independent imaging methods (IRT and ICG) revealed similar, but not identical, results. Subjective evaluation of the anastomosis performed by the team of three surgeons was more in agreement with the area detected by contactless thermography imaging. Moreover, the proceeding 'dynamic temperature return test', when the particular intestinal part was cooled and its subsequent temperature return was measured, revealed significant results. The time taken to return to the original intestinal temperature was greater for the devascular part of the intestine. SIGNIFICANCE: A thermographic examination could help to detect the correct location of the intestine resection line for further/continuing anastomosis creation.
