scholarly journals Feasibility of balloon-based endobiliary radiofrequency ablation under cholangioscopy guidance in a swine model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tadahisa Inoue ◽  
Hiromu Kutsumi ◽  
Mayu Ibusuki ◽  
Masashi Yoneda
Keyword(s):  
Radiofrequency Ablation ◽  
Adverse Events ◽  
Swine Model ◽  
Biliary Strictures ◽  
Tissue Samples ◽  
Ablation Area ◽  
Mucosal Changes ◽  
The Mean ◽  
Preliminary Study

AbstractAlthough endobiliary radiofrequency ablation (RFA) has demonstrated considerable potential for the treatment of biliary strictures, conventional catheter RFA has several limitations. This study aimed to evaluate the feasibility of a novel cholangioscopy (CS)-guided balloon-based RFA procedure in vivo using a swine model. CS-guided balloon-RFA was performed under endoscopic retrograde cholangiography guidance at target temperatures of 60 ℃ or 70 ℃, which were maintained for 60 s. We evaluated the technical feasibility, adverse events, and histological effects associated with the procedure. Twelve sites were ablated in seven miniature pigs. The CS-guided balloon-RFA procedure was technically successful in all cases without any hindrance. Mucosal changes could be detected during RFA, and the ablation area was identified on CS. Necropsy was performed in four pigs on the same day as the procedure: the tissue samples showed coagulative necrosis, and the entire internal circumference of the bile duct was uniformly ablated. The mean lengths of the ablation area in the samples ablated at 60 °C and 70 °C were 20.64 and 22.18 mm, respectively, while the mean depths were 3.46 and 5.07 mm, respectively. The other three pigs were reared and euthanized and autopsied 35 days after the procedure. The site to be ablated had replaced the granulation tissue and fibrotic changes. No adverse events were observed in any case. CS-guided balloon-RFA appears to be a promising option for treating biliary strictures. This preliminary study could pave the way for the evaluation of this procedure in future human clinical trials.

scholarly journals Reproducibility of Ablated Volume Measurement Is Higher with Contrast-Enhanced Ultrasound than with B-Mode Ultrasound after Benign Thyroid Nodule Radiofrequency Ablation—A Preliminary Study

2020 ◽  
Vol 9 (5) ◽  
pp. 1504 ◽  
Author(s):  
Simone Schiaffino ◽  
Francesca Serpi ◽  
Duccio Rossi ◽  
Valerio Ferrara ◽  
Ciriaco Buonomenna ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Thyroid Nodules ◽  
Observer Agreement ◽  
Contrast Enhanced Ultrasound ◽  
Limits Of Agreement ◽  
Contrast Enhanced ◽  
The Mean ◽  
Preliminary Study ◽  
Benign Thyroid Nodules ◽  
Benign Thyroid

The reproducibility of contrast-enhanced ultrasound (CEUS) and standard B-mode ultrasound in the assessment of radiofrequency-ablated volume of benign thyroid nodules was compared. A preliminary study was conducted on consecutive patients who underwent radiofrequency ablation (RFA) of benign thyroid nodules between 2014 and 2016, with available CEUS and B-mode post-ablation checks. CEUS and B-mode images were retrospectively evaluated by two radiologists to assess inter- and intra-observer agreement in the assessment of ablated volume (Bland–Altman test). For CEUS, the mean inter-observer difference (95% limits of agreement) was 0.219 mL (-0.372–0.809 mL); for B-mode, the mean difference was 0.880 mL (-1.655–3.414 mL). Reproducibility was significantly higher for CEUS (85%) than for B-mode (27%). Mean intra-observer differences (95% limits of agreement) were 0.013 mL (0.803–4.097 mL) for Reader 1 and 0.031 mL (0.763–3.931 mL) for Reader 2 using CEUS, while they were 0.567 mL (-2.180–4.317 mL, Reader 1) and 0.759 mL (-2.584–4.290 mL, Reader 2) for B-mode. Intra-observer reproducibility was significantly higher for CEUS (96% and 95%, for the two readers) than for B-mode (21% and 23%). In conclusion, CEUS had higher reproducibility and inter- and intra-observer agreement compared to conventional B-mode in the assessment of radiofrequency-ablated volume of benign thyroid nodules.

scholarly journals Influence of interapplicator distance on multibipolar radiofrequency ablation during physiological and interrupted liver perfusion in an in vivo porcine model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
F. G. M. Poch ◽  
C. A. Neizert ◽  
B. Geyer ◽  
O. Gemeinhardt ◽  
L. Bruder ◽  
...  
Keyword(s):  
Blood Flow ◽  
Radiofrequency Ablation ◽  
Hepatic Blood Flow ◽  
Early Stage ◽  
Liver Perfusion ◽  
Strict Adherence ◽  
Ablation Area ◽  
The Impact ◽  
Pringle Manoeuvre

Abstract Radiofrequency ablation (RFA) is a curative treatment option for early stage hepatocellular carcinoma (HCC). Vascular inflow occlusion to the liver (Pringle manoeuvre) and multibipolar RFA (mbRFA) represent possibilities to generate large ablations. This study evaluated the impact of different interapplicator distances and a Pringle manoeuvre on ablation area and geometry of mbRFA. 24 mbRFA were planned in porcine livers in vivo. Test series with continuous blood flow had an interapplicator distance of 20 mm and 15 mm, respectively. For a Pringle manoeuvre, interapplicator distance was predefined at 20 mm. After liver dissection, ablation area and geometry were analysed macroscopically and histologically. Confluent and homogenous ablations could be achieved with a Pringle manoeuvre and an interapplicator distance of 15 mm with sustained hepatic blood flow. Ablation geometry was inhomogeneous with an applicator distance of 20 mm with physiological liver perfusion. A Pringle manoeuvre led to a fourfold increase in ablation area in comparison to sustained hepatic blood flow (p < 0.001). Interapplicator distance affects ablation geometry of mbRFA. Strict adherence to the planned applicator distance is advisable under continuous blood flow. The application of a Pringle manoeuvre should be considered when compliance with the interapplicator distance cannot be guaranteed.

scholarly journals Impact of Successful Choanal Atresia Repair on the Nasal Mucosa: A Preliminary Study

2017 ◽  
Vol 21 (03) ◽  
pp. 276-280 ◽  
Author(s):  
Ezzeddin Elsheikh ◽  
Mohammad El-Anwar ◽  
Hesham Abdel-aziz
Keyword(s):  
Nasal Mucosa ◽  
Choanal Atresia ◽  
Inferior Turbinate ◽  
Tissue Samples ◽  
Histological Features ◽  
Submucosal Glands ◽  
Mucosal Changes ◽  
Preliminary Study ◽  
Immunohistochemical Studies ◽  
Goblet Cell Density

Introduction The main histological features of the nasal mucosa in choanal atresia are distorted cilia, marked increase of mucous submucosal glands associated with marked reduction of goblet cell density, and lymphocytic cellular infiltration. Objective To study the nasal mucosal changes in cases of choanal atresia after successful repair compared with pre-repair mucosal histological features. Methods Tissue samples were taken from the inferior turbinate of 3 patients (1 bilateral and 2 unilateral) who were successfully operated. Then, the biopsies were subjected to histopathological, histochemical and immunohistochemical studies. After that, the results were compared with pre-repair findings in the choanal atresia side and in the normal side. Results Four biopsies (4 repaired choanal atresia sides) of the mucosa of the inferior turbinate revealed that 1 patient (who had a bilateral choanal atresia repaired), after achieving a patent choana for 8 months, had not completely recovered a normal nasal mucosa. The other 2 patients, after 18 and 23 months of achieving a patent choana, showed normal nasal cavities. Conclusion The main histological features of the nasal mucosa in choanal atresia could be reversed by surgery, making the patients regain their choanal patency, with their mucosae changing back to normal gradually with time.

Su1614 Histologic Effect of In Vivo Radiofrequency Ablation on Bile Duct in Swine Model: a Preliminary Experiment

2014 ◽  
Vol 79 (5) ◽  
pp. AB340
Author(s):  
Seok Jeong ◽  
Don Haeng Lee ◽  
Yong Woon Shin ◽  
Hyung Kil Kim ◽  
Byoung Wook Bang ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Bile Duct ◽  
Swine Model ◽  
Histologic Effect

scholarly journals Endoscopic Radiofrequency Ablation of the Sacroiliac Joint Complex in the Treatment of Chronic Low Back Pain: A Preliminary Study of Feasibility and Efficacy of a Novel Technique

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Won-Suh Choi ◽  
Jin-Sung Kim ◽  
Kyeong-Sik Ryu ◽  
Jung-Woo Hur ◽  
Ji-Hoon Seong ◽  
...  
Keyword(s):  
Radiofrequency Ablation ◽  
Sacroiliac Joint ◽  
Invasive Technique ◽  
Bipolar Radiofrequency ◽  
Endoscopic Radiofrequency Ablation ◽  
The Mean ◽  
Preliminary Study ◽  
Lateral Branches ◽  
Duration Of Operation

Background. Radiofrequency ablation (RFA) is a less invasive technique for treatment of sacroiliac joint (SIJ) pain. Objective. To evaluate the feasibility and efficacy of endoscope-guided RFA for the treatment of CLBP from the SIJ complex. Methods. In this retrospective study, the medical records of 17 patients who underwent endoscope-guided RFA of the SIJ complex were reviewed. A bipolar radiofrequency probe was used to lesion the posterior capsule of the SIJ as well as the lateral branches of S1, S2, S3, and the L5 dorsal ramus in multiple locations. We visualized the ablation area using endoscope. We assessed visual analogue scale (VAS) and the Oswestry disability index (ODI) preoperatively, immediately postop, and at 1-, 3-, and 6-month postop outpatient clinic visits. Patient satisfaction of the procedure was assessed in percentages. Results. The mean duration of operation was 20 to 50 minutes. The mean VAS and the ODI scores decreased significantly immediately after the procedure and were kept significantly lower than baseline levels during the follow-up periods. No complications occurred perioperatively and during the follow-up periods. 88.6% of patients were satisfied with the procedure. Conclusions. Our preliminary results suggest that endoscope-guided RFA may be alternative option to treat CLBP secondary to SIJ complex.

Biomedical applications: Pitfalls in the practice

1994 ◽  
Vol 52 ◽  
pp. 378-379
Author(s):  
J. D. Shelburne ◽  
Peter Ingram ◽  
Victor L. Roggli ◽  
Ann LeFurgey
Keyword(s):  
Operating Room ◽  
Liquid Nitrogen ◽  
Lung Tissue ◽  
Biomedical Applications ◽  
Microprobe Analysis ◽  
Tissue Sample ◽  
Cellular Level ◽  
Tissue Samples ◽  
Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

Scintigraphic Detection of Experimental Myocardial Infarction with 99mTc-2,3-Dimercaptosuccinic Acid

1984 ◽  
Vol 23 (06) ◽  
pp. 317-319
Author(s):  
J. Novák ◽  
Y. Mazurová ◽  
J. Kubíček ◽  
J. Yižd’a ◽  
P. Kafka ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Intravenous Administration ◽  
Experimental Myocardial Infarction ◽  
Myocardial Infarctions ◽  
Clinical Use ◽  
Scintigraphic Imaging ◽  
Tissue Samples ◽  
Scintigraphic Finding

SummaryAcute myocardial infarctions were produced by ligature of the left frontal descending coronary artery in 9 dogs. The possibility of scintigraphic imaging with 99mTc-DMSA 4 hrs after intravenous administration was studied. The infarctions were 4, 24 and 48 hrs old. The in vivo scan was positive in only one dog with a 4-hr old infarction. The in vivo scans were confirmed by the analysis of the radioactivity in tissue samples. The accumulation of the radiopharmaceutical increased slightly in 48-hr old lesions; however, this increase was not sufficient for a positive scintigraphic finding. Thus, we do not recommend 99mTc-DMSA for clinical use in acute lesions.

Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

1996 ◽  
Vol 76 (01) ◽  
pp. 111-117 ◽  
Author(s):  
Yasuto Sasaki ◽  
Junji Seki ◽  
John C Giddings ◽  
Junichiro Yamamoto
Keyword(s):  
Blood Flow ◽  
Thrombus Formation ◽  
Dependent Manner ◽  
Red Cell ◽  
Cell Velocity ◽  
Red Cell Velocity ◽  
The Mean ◽  
Wall Shear ◽  
Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

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