High-intensity focused ultrasound ablation of muscle in an anticoagulated swine model.

Introduction: Image-guided non-invasive high-intensity focused ultrasound (HIFU) has been gaining recognition in treating musculoskeletal tumors and desmoids. However, there is no consensus on the appropriate perioperative management for patients on ongoing anticoagulation who undergo HIFU ablation.

Material And Methods: Image-guided HIFU treatment was performed in swine on an ongoing oral anticoagulation protocol ( = 5) in two treatment sessions seven days apart.

The Mouse Round-window Approach for Ototoxic Agent Delivery: A Rapid and Reliable Technique for Inducing Cochlear Cell Degeneration.

Investigators have utilized a wide array of animal models and investigative techniques to study the mammalian auditory system. Much of the basic research involving the cochlea and its associated neural pathways entails exposure of model cochleae to a variety of ototoxic agents. This allows investigators to study the effects of targeted damage to cochlear structures, and in some cases, the self-repair or regeneration of those structures.

Feasibility Study on MR-Guided High-Intensity Focused Ultrasound Ablation of Sciatic Nerve in a Swine Model: Preliminary Results.

Introduction: Spastic patients often seek neurolysis, the permanent destruction of the sciatic nerve, for better pain management. MRI-guided high-intensity focused ultrasound (MRgHIFU) may serve as a noninvasive alternative to the prevailing, more intrusive techniques. This in vivo acute study is aimed at performing sciatic nerve neurolysis using a clinical MRgHIFU system.

Characterization of bone perfusion by dynamic contrast-enhanced magnetic resonance imaging and positron emission tomography in the Dunkin-Hartley guinea pig model of advanced osteoarthritis.

This study characterizes changes in subchondral bone circulation in OA and examines relationships to bone structure and cartilage degeneration in Dunkin-Hartley guinea pigs. We have used dynamic contrast-enhanced MRI (DCE-MRI) and PET, with pharmacokinetic modeling, to characterize subchondral bone perfusion. Assessments are made of perfusion kinetics and vascular permeability by MRI, and blood volume and flow, and radionuclide incorporation into bone, by PET.

Feasibility and Safety of Laparoscopic Colon Surgery Performed Under Intravenous Sedation and Local Anesthesia Using Microinvasive (<3 mm) Instruments: An Acute and Survival Study on Porcine Model.

Purpose: The purpose of the study was to evaluate the feasibility and safety of performing laparoscopic intestinal surgery using local anesthesia and intravenous sedation with instruments <3 mm in diameter.

Methods: Porcine model with acute (n = 2) and the survival studies (n = 8): all female pigs, weight (median 36.4 kg, range 33.

Planning irreversible electroporation in the porcine kidney: are numerical simulations reliable for predicting empiric ablation outcomes?

Purpose: Numerical simulations are used for treatment planning in clinical applications of irreversible electroporation (IRE) to determine ablation size and shape. To assess the reliability of simulations for treatment planning, we compared simulation results with empiric outcomes of renal IRE using computed tomography (CT) and histology in an animal model.

Methods: The ablation size and shape for six different IRE parameter sets (70-90 pulses, 2,000-2,700 V, 70-100 µs) for monopolar and bipolar electrodes was simulated using a numerical model.

Intraoperative ultrasound and tissue elastography measurements do not predict the size of hepatic microwave ablations.

Rationale And Objectives: Image-guided thermal ablation is used to treat primary and secondary liver cancers. Evaluating completeness of ablation is difficult with standard intraoperative B-mode ultrasound. This study evaluates the ability of B-mode ultrasound (US) and tissue elastography to adequately measure the extent of ablation compared to pathologic assessment.

Novel use of noninvasive high-intensity focused ultrasonography for intercostal nerve neurolysis in a swine model.

Background: High-intensity focused ultrasound (HIFU) is a noninvasive thermal ablation technique. High-intensity focused ultrasound has been used in small-animal models to lesion neural tissue selectively. This study aimed to evaluate the efficacy of HIFU in a large-animal model for ablation of nerves similar in size to human nerves.

MRI-safe robot for targeted transrectal prostate biopsy: animal experiments.

Objectives: To study the feasibility and safety of using a magnetic resonance imaging (MRI)-safe robot for assisting MRI-guided transrectal needle placement and biopsy in the prostate, using a canine model. To determine the accuracy and precision afforded by the use of the robot while targeting a desired location in the organ.

Materials And Methods: In a study approved by the Institutional Animal Care and Use Committee, six healthy adult male beagles with prostates of at least 15 × 15 mm in size at the largest transverse section were chosen for the procedure.

Irreversible electroporation facilitates gene transfer of a GM-CSF plasmid with a local and systemic response.

Background: Electroporation uses an electric field to induce pores in the cell membrane that can transfer macromolecules into target cells. Modulation of electrical parameters leads to irreversible electroporation (IRE), which is being developed for tissue ablation. We sought to evaluate whether the application of IRE may induce a lesser electric field in the periphery where reversible electroporation may occur, facilitating gene transfer of a granulocyte macrophage colony-stimulating factor (GM-CSF) plasmid to produce its biologic response.

Comparison of simulation-based treatment planning with imaging and pathology outcomes for percutaneous CT-guided irreversible electroporation of the porcine pancreas: a pilot study.

Purpose: To investigate the reliability of simulations for planning pancreatic irreversible electroporation (IRE) ablations compared with computed tomography (CT) and pathology outcomes in an animal model.

Materials And Methods: Simulations were performed varying treatment parameters, including field strength (1.5-2.

Evaluation of an endorectal electrode for performing focused irreversible electroporation ablations in the Swine rectum.

Purpose: To study the feasibility of a novel endorectal electrode for the creation of focal ablations of the rectal wall with the use of irreversible electroporation (IRE).

Materials And Methods: A monopolar electrode with a grounding pad (10 ablations in five pigs) and a bipolar electrode (two ablations in one pig) were evaluated in healthy swine rectum. A two-dimensional model of the electrode in the rectum was created and used to solve the Laplace equation to determine field strength.

Endoscopic spray cryotherapy for genitourinary malignancies: safety and efficacy in a porcine model.

Objective: To examine the effects and safety of using endoscopic spray cryotherapy (ESC) on bladder, ureteral, and renal pelvis urothelium in a live porcine model.

Subjects And Methods: ESC treatments were systematically applied to urothelial sites in the bladder, ureter, and renal pelvis of eight female Yorkshire swine in a prospective trial. Freeze-thaw cycles ranged from 5 to 60 s/cycle for one to six cycles using a 7 French cryotherapy catheter.

Neutrophil gelatinase-associated lipocalin (NGAL) levels in response to unilateral renal ischaemia in a novel pilot two-kidney porcine model.

Objectives: To test a novel porcine two-kidney model for evaluating the effect of controlled acute kidney injury (AKI) related to induced unilateral ischaemia on both renal units (RUs) To use neutrophil gelatinase-associated lipocalin (NGAL) and physiological serum and urinary markers to assess AKI and renal function.

Methods: Twelve female Yorkshire pigs had bilateral cutaneous ureterostomies placed laparoscopically with identical duration of pneumoperitoneum for all cases. An experimental group (n = 9) underwent induced unilateral renal ischaemia with left hilar clamping of timed duration (15, 30, 60 min) and a control group (n = 3) had no induced renal ischaemia.

Irreversible electroporation ablation of the liver can be detected with ultrasound B-mode and elastography.

Background: Irreversible electroporation (IRE) is a novel ablation technique that induces permanent membrane permeability and cell death. We are interested in ultrasound B-mode and elastography to monitor IRE ablation in the liver.

Methods: Yorkshire pigs underwent IRE ablation of the liver and were imaged with ultrasound B-mode and elastography.

Interstitial laser-induced thermotherapy of the lung: evaluation of the influence of ablation continuity on ablation size in a swine model.

The purpose of this study was to assess the relationship between size and the continuity of energy application in interstitial laser-induced thermotherapy. Percutaneous computed tomography-guided laser ablation (30 W, 600 nm diode) of the lung was performed in 7 Yorkshire pigs; a total of 42 ablation zones were created. Twenty ablations were performed using a continuous cycle of 2 min (protocol A) and 22 ablations were performed using 4 intermittent cycles with a duration of 1 min for each cycle interrupted by a 10-s stop between the cycles (protocol B).

Palatability and treatment efficacy of various ibuprofen formulations in C57BL/6 mice with ulcerative dermatitis.

Ibuprofen, a nonsteroidal antiinflammatory drug, is a nonselective inhibitor of cyclooxygenases 1 and 2 that commonly is used for its analgesic, antiinflammatory, and antipyretic properties. We compared the palatability and efficacy of medicated water containing ibuprofen from an oral pediatric suspension or liqui-gel capsules in C57BL/6 and genetically engineered mice of C57BL/6 background with ulcerative dermatitis. Mice (n = 14 or 15 per group) with ulcerated skin lesions of similar average size (capsule group, 6.

The delayed effects of irreversible electroporation ablation on nerves.

Objective: To evaluate the delayed effects of irreversible electroporation (IRE) ablation on nerves.

Methods: The study was approved by the institutional animal care and use committee. CT-guided IRE-ablation (electric field per distance, 1,500 V/cm; pulse length, 70 μs; number of pulses, 90) of 6 sciatic nerves was performed in 6 pigs that were euthanized 2 months after ablation.

Irreversible electroporation adjacent to the rectum: evaluation of pathological effects in a pig model.

Purpose: To evaluate the effects of irreversible electroporation (IRE) on the rectum wall after IRE applied adjacent to the rectum.

Material And Methods: CT-guided IRE adjacent to the rectum wall was performed in 11 pigs; a total of 44 lesions were created. In five pigs, ablations were performed without a water-filled endorectal coil (group A); in six pigs, ablation was performed with the coil to avoid displacement of the rectum wall (group B).

Flexible CO2 laser and submucosal gel injection for safe endoluminal resection in the intestines.

Background: The CO(2) laser's unique wavelength of 10.6 μm has the advantage of being readily absorbed by water but historically limited it to line-of-sight procedures. Through recent technological advances, a flexible CO(2) laser fiber has been developed and holds promise for endoluminal surgery.

Irreversible electroporation is a surgical ablation technique that enhances gene transfer.

Background: Reversible electroporation has long been used to transfer macromolecules into target cells in the laboratory by using an electric field to induce transient membrane permeability. Recently, the electric field has been modulated to produce permanent membrane permeability and cell death. This novel technique, irreversible electroporation (IRE), is being developed for nonthermal cancer ablation.

Acute and subacute effects of irreversible electroporation on nerves: experimental study in a pig model.

Purpose: To evaluate whether irreversible electroporation (IRE) has the potential to damage nerves in a porcine model and to compare histopathologic findings after IRE with histopathologic findings after radiofrequency ablation (RFA).

Materials And Methods: This study was approved by the institutional animal care and use committee. Computed tomography (CT)-guided IRE of 11 porcine sciatic nerves was performed in nine pigs, and histopathologic analysis was performed on the day of ablation or 3, 6, or 14 days after ablation.