scholarly journals Radiofrequency ablation of pancreas and optimal cooling of peripancreatic tissue in an ex-vivo porcine model

2011 ◽  
Vol 80 (4) ◽  
pp. 407-413 ◽  
Author(s):  
Michal Crha ◽  
Jan Hlavsa ◽  
Vladimír Procházka ◽  
Tomáš Andrašina ◽  
Iva Svobodová ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Portal Vein ◽  
Thermal Injury ◽  
Porcine Model ◽  
Continuous Measurement ◽  
Ex Vivo ◽  
Porcine Pancreas ◽  
Cooling Method ◽  
Duodenal Lumen ◽  
Pancreatic Neoplasia

Radiofrequency ablation is a possible palliative treatment for patients suffering from pancreatic neoplasia. However, radiofrequency-induced damage to the peripancreatic tissues during pancreatic ablation might cause fatal complications. The aim of this experimental ex vivo study on pigs was to verify ablation protocols and evaluate whether or not the cooling of peripancereatic tissues during pancreatic ablation has any benefit for their protection against thermal injury. Radiofrequency ablation was performed on 52 pancreatic specimens obtained from pigs. During each pancreatic ablation, continuous measurements of the temperature in the portal vein and duodenal lumen were performed. Peripancreatic tissues were either not cooled or were cooled by being submerged in 14 °C water, or by a perfusion of the portal vein and duodenum with 14 °C saline. The effects of variation in target temperature of the ablated area (90 °C and 100 °C), duration of ablation (5 and 10 min) and the effect of peripancreatic tissues cooling were studied. We proved that optimal radiofrequency ablation of the porcine pancreas can be reached with the temperature of 90  °C for 5 min in the ablated area. The perfusion of the duodenal and portal vein by 14 °C saline was found to be the most effective cooling method for minimizing damage to the walls. Continuous measurement of temperatures in peripancreatic tissues will provide useful feedback to assist in their protection against thermal injury. This therapy could be used in the treatment of pancreatic tumours.

Differential Outcomes for Long Term ex vivo Lung Perfusion in a Porcine Model - With or without Red Cells?

2015 ◽  
Vol 63 (S 01) ◽  
Author(s):  
W. Sommer ◽  
M. Avsar ◽  
J. Salman ◽  
C. Kühn ◽  
I. Tudorache ◽  
...  
Keyword(s):  
Porcine Model ◽  
Ex Vivo ◽  
Lung Perfusion ◽  
Red Cells ◽  
Ex Vivo Lung Perfusion ◽  
Differential Outcomes

scholarly journals Robotic-assisted cholecystectomy is superior to laparoscopic cholecystectomy in the initial training for surgical novices in an ex vivo porcine model: a randomized crossover study

2021 ◽  
Author(s):  
E. Willuth ◽  
S. F. Hardon ◽  
F. Lang ◽  
C. M. Haney ◽  
E. A. Felinska ◽  
...  
Keyword(s):  
Laparoscopic Cholecystectomy ◽  
Crossover Study ◽  
Porcine Model ◽  
Haptic Feedback ◽  
Ex Vivo ◽  
Operating Time ◽  
Surgical Performance ◽  
Robotic Assisted ◽  
Subjective Workload ◽  
Randomized Crossover Study

Abstract Background Robotic-assisted surgery (RAS) potentially reduces workload and shortens the surgical learning curve compared to conventional laparoscopy (CL). The present study aimed to compare robotic-assisted cholecystectomy (RAC) to laparoscopic cholecystectomy (LC) in the initial learning phase for novices. Methods In a randomized crossover study, medical students (n = 40) in their clinical years performed both LC and RAC on a cadaveric porcine model. After standardized instructions and basic skill training, group 1 started with RAC and then performed LC, while group 2 started with LC and then performed RAC. The primary endpoint was surgical performance measured with Objective Structured Assessment of Technical Skills (OSATS) score, secondary endpoints included operating time, complications (liver damage, gallbladder perforations, vessel damage), force applied to tissue, and subjective workload assessment. Results Surgical performance was better for RAC than for LC for total OSATS (RAC = 77.4 ± 7.9 vs. LC = 73.8 ± 9.4; p = 0.025, global OSATS (RAC = 27.2 ± 1.0 vs. LC = 26.5 ± 1.6; p = 0.012, and task specific OSATS score (RAC = 50.5 ± 7.5 vs. LC = 47.1 ± 8.5; p = 0.037). There were less complications with RAC than with LC (10 (25.6%) vs. 26 (65.0%), p = 0.006) but no difference in operating times (RAC = 77.0 ± 15.3 vs. LC = 75.5 ± 15.3 min; p = 0.517). Force applied to tissue was similar. Students found RAC less physical demanding and less frustrating than LC. Conclusions Novices performed their first cholecystectomies with better performance and less complications with RAS than with CL, while operating time showed no differences. Students perceived less subjective workload for RAS than for CL. Unlike our expectations, the lack of haptic feedback on the robotic system did not lead to higher force application during RAC than LC and did not increase tissue damage. These results show potential advantages for RAS over CL for surgical novices while performing their first RAC and LC using an ex vivo cadaveric porcine model. Registration number researchregistry6029 Graphic abstract

scholarly journals Optical signatures of radiofrequency ablation in biological tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pranav Lanka ◽  
Kalloor Joseph Francis ◽  
Hindrik Kruit ◽  
Andrea Farina ◽  
Rinaldo Cubeddu ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Treatment Time ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Tissue Response ◽  
Optical Monitoring ◽  
Diffuse Optical Spectroscopy ◽  
Spectral Changes ◽  
Scattering Spectra ◽  
Optical Behavior

AbstractAccurate monitoring of treatment is crucial in minimally-invasive radiofrequency ablation in oncology and cardiovascular disease. We investigated alterations in optical properties of ex-vivo bovine tissues of the liver, heart, muscle, and brain, undergoing the treatment. Time-domain diffuse optical spectroscopy was used, which enabled us to disentangle and quantify absorption and reduced scattering spectra. In addition to the well-known global (1) decrease in absorption, and (2) increase in reduced scattering, we uncovered new features based on sensitive detection of spectral changes. These absorption spectrum features are: (3) emergence of a peak around 840 nm, (4) redshift of the 760 nm deoxyhemoglobin peak, and (5) blueshift of the 970 nm water peak. Treatment temperatures above 100 °C led to (6) increased absorption at shorter wavelengths, and (7) further decrease in reduced scattering. This optical behavior provides new insights into tissue response to thermal treatment and sets the stage for optical monitoring of radiofrequency ablation.

scholarly journals Development of a gel dedicated to gel immersion endoscopy

2021 ◽  
Vol 09 (06) ◽  
pp. E918-E924
Author(s):  
Tomonori Yano ◽  
Atsushi Ohata ◽  
Yuji Hiraki ◽  
Makoto Tanaka ◽  
Satoshi Shinozaki ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Porcine Model ◽  
Ex Vivo ◽  
In Vitro Experiments ◽  
Efficacy And Safety ◽  
Coagulative Necrosis ◽  
Novel Technique ◽  
In Vivo Experiments

Abstract Backgrounds and study aims Gel immersion endoscopy is a novel technique to secure the visual field during endoscopy. The aim of this study was to develop a dedicated gel for this technique. Methods To identify appropriate viscoelasticity and electrical conductivity, various gels were examined. Based on these results, the dedicated gel “OPF-203” was developed. Efficacy and safety of OPF-203 were evaluated in a porcine model. Results  In vitro experiments showed that a viscosity of 230 to 1900 mPa·s, loss tangent (tanδ) ≤ 0.6, and hardness of 240 to 540 N/cm2 were suitable. Ex vivo experiments showed electrical conductivity ≤ 220 μS/cm is appropriate. In vivo experiments using gastrointestinal bleeding showed that OPF-203 provided clear visualization compared to water. After electrocoagulation of gastric mucosa in OPF-203, severe coagulative necrosis was not observed in the muscularis but limited to the mucosa. Conclusions OPF-203 is useful for gel immersion endoscopy.

Hyperspectral image-based analysis of thermal damage for ex-vivo bovine liver utilizing radiofrequency ablation

2021 ◽  
pp. 101564
Author(s):  
Mohamed Hisham Aref ◽  
Ibrahim H. Aboughaleb ◽  
Abou-Bakr M. Youssef ◽  
Yasser H. El-Sharkawy
Keyword(s):  
Radiofrequency Ablation ◽  
Thermal Damage ◽  
Hyperspectral Image ◽  
Ex Vivo ◽  
Bovine Liver

scholarly journals Fiber optic dual EFPI/FBG for radiofrequency ablation monitoring in liver: ex-vivo experiments

2014 ◽  
Author(s):  
Daniele Tosi ◽  
Edoardo Gino Macchi ◽  
Giovanni Braschi ◽  
Mario Gallati ◽  
Alfredo Cigada ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Fiber Optic ◽  
Ex Vivo
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