Vessel-Sealing Capability of Novel Microwave Sealer: Experimental Study in Animal Models

2020 ◽  
pp. 155335062093786
Author(s):  
Khiem Tran Dang ◽  
Shigeyuki Naka ◽  
Atsushi Yamada ◽  
Ken-ichi Mukaisho ◽  
Tohru Tani
Keyword(s):  
Thermal Damage ◽  
Ex Vivo ◽  
Vessel Diameter ◽  
Heating Process ◽  
Damage Evaluation ◽  
Vessel Sealing ◽  
Surgical Devices ◽  
Harmonic Focus ◽  
Thermal Spread

Background. Ultrasonically activated dissectors (UADs) and radiofrequency-based devices have been considered excellent surgical devices because of their reliability and flexibility. Meanwhile, microwave-based devices have demonstrated potential with their unique heating mechanism. This study aims to compare the sealing function of a newly invented forceps-like microwave sealer (MS) with that of currently available UADs. Materials and Methods. MS and 2 examples of UADs (Harmonic Focus+ [HF+] and Sonicision [SNC]) were employed to perform mesenterectomies (in vivo) and sealing sizable vessels (ex vivo). Vessel diameter, seal time, burst pressure (BP), sealing completion, and instrument sticking were recorded. The samples underwent histological investigation for thermal damage evaluation. Results. During mesenterectomies, MS required 3 seconds and 30 W to secure a complete seal. The BP achieved by the MS seal was higher than that of HF+ and SNC on arteries (851 ± 203.7 vs 682.4 ± 287.3, P < .05; vs 833.1 ± 251.2 mmHg, P = .4523, respectively) but was not statistically different on veins (324.9 ± 203.5 vs 460.1 ± 320.3 vs 508.3 ± 350.7 mmHg, P = .215). In all trials, MS caused less sticking but exhibited similar heat-induced alterations to UADs. MS’s thermal spread was not statistically more extended than that of UADs on either arteries or veins. Conclusions. MS was capable of not only sealing tiny vessels but also achieving high-pressure endurance on sizable vessels. Its forceful grasping and synchronous heating process helped create solid stumps with an acceptable thermal spread.

scholarly journals Monopolar Electrosurgical Thermal Management System to Reduce Lateral Thermal Damage During Surgery

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Robert Dodde ◽  
Jacob S. Gee ◽  
James D. Geiger ◽  
Albert J. Shih
Keyword(s):  
Thermal Management ◽  
Heat Generation ◽  
Tissue Damage ◽  
Management System ◽  
Thermal Damage ◽  
Ex Vivo ◽  
Resistive Heating ◽  
Thermal Management System ◽  
Thermal Spread

A monopolar electrosurgical device is the most commonly used energy-based surgical instrument. Monopolar devices are primarily applied to incise, ablate, dissect, and coagulate tissue by transferring electrical energy to the tissue in the form of heat generation through resistive heating. The substantial amount of heat created by the monopolar device has been shown to spread throughout the tissue, creating unintended tissue damage, which can lead to nerve thermal damage and loss of normal bodily functions. Due to this fact, energy-based devices have had a limited use in surgical procedures performed near neurovascular bundles. The extent to which the generated heat raises the temperature of the surrounding tissue is referred to as the device’s thermal spread. In this study, ex vivo and in vivo experiments have shown that a novel thermal management system (TMS) can reduce the amount of thermal spread created by a typical monopolar device, thus eliminating the thermal collateral tissue damage typically caused during a monopolar procedure. The incorporation of a TMS consisting of adjacent cooling channels reduces the thermal spread of the device, as illustrated in a reduction as high as 50% in the maximum temperature recorded during an in vivo experimental procedure. The design of the TMS was aided by finite element modeling (FEM). The phenomenon of monopolar resistive heating was modeled to analyze the temperature distributions in biological tissue subjected to heat generation by a commonly used monopolar electrosurgical device. The mathematical model was verified by comparing the model’s predicted temperature distribution with experimental results. Ex vivo experiments were performed with liver tissue heated by a monopolar pencil electrode. The experimental data for 1 mm distance from the electrode are seen to fit within 1% of the predicted temperature values by the FEM simulation.

An Innovative Ex Vivo Vascular Bioreactor as Comprehensive Tool to Study the Behavior of Native Blood Vessels Under Physiologically Relevant Conditions

2019 ◽  
Vol 2 (4) ◽  
Author(s):  
Noemi Vanerio ◽  
Marco Stijnen ◽  
Bas A. J. M. de Mol ◽  
Linda M. Kock
Keyword(s):  
Shear Stress ◽  
Blood Vessels ◽  
Ultrasound Imaging ◽  
Ex Vivo ◽  
Biological Response ◽  
Vessel Diameter ◽  
Tissue Growth ◽  
In Vivo Models

Abstract Ex vivo systems represent important models to study vascular biology and to test medical devices, combining the advantages of in vitro and in vivo models such as controllability of parameters and the presence of biological response, respectively. The aim of this study was to develop a comprehensive ex vivo vascular bioreactor to long-term culture and study the behavior of native blood vessels under physiologically relevant conditions. The system was designed to allow for physiological mechanical loading in terms of pulsatile hemodynamics, shear stress, and longitudinal prestretch and ultrasound imaging for vessel diameter and morphology evaluation. In this first experience, porcine carotid arteries (n = 4) from slaughterhouse animals were cultured in the platform for 10 days at physiological temperature, CO2 and humidity using medium with blood-mimicking viscosity, components, and stability of composition. As expected, a significant increase in vessel diameter was observed during culture. Flow rate was adjusted according to diameter values to reproduce and maintain physiological shear stress, while pressure was kept physiological. Ultrasound imaging showed that the morphology and structure of cultured arteries were comparable to in vivo. Histological analyses showed preserved endothelium and extracellular matrix and neointimal tissue growth over 10 days of culture. In conclusion, we have developed a comprehensive pulsatile system in which a native blood vessel can be cultured under physiological conditions. The present model represents a significant step toward ex vivo testing of vascular therapies, devices, drug interaction, and as basis for further model developments.

The Thermal Safety Profile of a New Bipolar Vessel Sealing Device for Thyroid Surgery

2021 ◽  
Vol 39 ◽  
Author(s):  
Aman Prasad ◽  
◽  
Jessica Durrant ◽  
Daniel Smeak ◽  
Jason Newman ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Thyroid Surgery ◽  
Thermal Injury ◽  
Thermal Damage ◽  
Vascular Bundles ◽  
En Bloc ◽  
Vessel Sealing ◽  
Adjacent Structures ◽  
Sealing Device

Introduction: Bipolar electrocautery devices used to achieve intraoperative hemostasis carry risk of imparting thermal energy to adjacent tissue, leading to postoperative morbidity. The aim of this study was to compare a new vessel sealing device, the CoolSeal™ Reveal (Bolder Surgical, Louisville, Colorado), with an established industry standard device, the LigaSure™ Exact Dissector (Valleylab, Boulder, Colorado), to assess their safety and the extent to which they impart thermal damage to tissue during thyroid surgery. Materials and Methods: Vascular bundles associated with the thyroid gland in anesthetized sheep were exposed and sealed with a single activation of each device and excised en bloc. Additionally, vascular structures of the sheep were also sealed 0, 1, or 2mm adjacent to the recurrent laryngeal nerve (RLN). Vascular and RLN samples were processed for histopathologic evaluation and assessed for extent of thermal injury, seal width, and coagulative changes. Results: The mean thermal injury extent across all sample sizes and vessel types was significantly lower for the CoolSeal™ Reveal device (547.2 ± 27.9μm) compared to the LigaSure™ device (802.7± 48.6μm) (p<0.001). Seal widths were significantly smaller in samples sealed with the CoolSeal™ Reveal device (899.0 ± 14.9μm) than samples sealed with the LigaSure™ device (1645.3 ± 160.3μm) (p<0.001). Conclusion: The CoolSeal™ Reveal device demonstrates significantly lower thermal spread in vivo compared to the LigaSure™ Exact Dissector. These results indicate that the CoolSeal™ Reveal is an effective tool for sealing blood vessels and minimizing thermal damage to adjacent structures during delicate surgeries or in narrow surgical fields associated with the thyroid gland.

Can Harmonic Focus Curved Shear Effectively Seal the Pancreatic Ducts and Prevent Pancreatic Leak? Feasibility Evaluation and Testing in Ex Vivo and In Vivo Porcine Models

2009 ◽  
Vol 157 (2) ◽  
pp. 279-283 ◽  
Author(s):  
Ronald S. Chamberlain ◽  
Donna Korvick ◽  
Mary Mootoo ◽  
Sara Story ◽  
Beata Dubiel ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Pancreatic Ducts ◽  
Pancreatic Leak ◽  
Harmonic Focus ◽  
Feasibility Evaluation

scholarly journals Inversion of neurovascular coupling after subarachnoid hemorrhage in vivo

2017 ◽  
Vol 37 (11) ◽  
pp. 3625-3634 ◽  
Author(s):  
Matilde Balbi ◽  
Masayo Koide ◽  
George C Wellman ◽  
Nikolaus Plesnila
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Neuronal Activity ◽  
Ex Vivo ◽  
Brain Slices ◽  
Neurovascular Coupling ◽  
Vessel Diameter ◽  
Cerebral Arterioles

Subarachnoid hemorrhage (SAH) induces acute changes in the cerebral microcirculation. Recent findings ex vivo suggest neurovascular coupling (NVC), the process that increases cerebral blood flow upon neuronal activity, is also impaired after SAH. The aim of the current study was to investigate whether this occurs also in vivo. C57BL/6 mice were subjected to either sham surgery or SAH by filament perforation. Twenty-four hours later NVC was tested by forepaw stimulation and CO2 reactivity by inhalation of 10% CO2. Vessel diameter was assessed in vivo by two-photon microscopy. NVC was also investigated ex vivo using brain slices. Cerebral arterioles of sham-operated mice dilated to 130% of baseline upon CO2 inhalation or forepaw stimulation and cerebral blood flow (CBF) increased. Following SAH, however, CO2 reactivity was completely lost and the majority of cerebral arterioles showed paradoxical constriction in vivo and ex vivo resulting in a reduced CBF response. As previous results showed intact NVC 3 h after SAH, the current findings indicate that impairment of NVC after cerebral hemorrhage occurs secondarily and is progressive. Since neuronal activity-induced vasoconstriction (inverse NVC) is likely to further aggravate SAH-induced cerebral ischemia and subsequent brain damage, inverse NVC may represent a novel therapeutic target after SAH.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Antithrombotic Effects and Bleeding Time Prolongation with Synthetic Platelet GPIIb/llla Inhibitors in Animal Models of Platelet-Mediated Thrombosis

1994 ◽  
Vol 71 (01) ◽  
pp. 095-102 ◽  
Author(s):  
Désiré Collen ◽  
Hua Rong Lu ◽  
Jean-Marie Stassen ◽  
Ingrid Vreys ◽  
Tsunehiro Yasuda ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Bleeding Time ◽  
Bolus Injection ◽  
Cell Injury ◽  
Ex Vivo ◽  
Thrombus Formation ◽  
Femoral Vein ◽  
Thrombotic Occlusion ◽  
Antithrombotic Effects

SummaryCyclic Arg-Gly-Asp (RGD) containing synthetic peptides such as L-cysteine, N-(mercaptoacetyl)-D-tyrosyl-L-arginylglycyl-L-a-aspartyl-cyclic (1→5)-sulfide, 5-oxide (G4120) and acetyl-L-cysteinyl-L-asparaginyl-L-prolyl-L-arginyl-glycyl-L-α-aspartyl-[0-methyltyrosyl]-L-arginyl-L-cysteinamide, cyclic 1→9-sulfide (TP9201) bind with high affinity to the platelet GPIIb/IIIa receptor.The relationship between antithrombotic effect, ex vivo platelet aggregation and bleeding time prolongation with both agents was studied in hamsters with a standardized femoral vein endothelial cell injury predisposing to platelet-rich mural thrombosis, and in dogs with a carotid arterial eversion graft inserted in the femoral artery. Intravenous administration of G4120 in hamsters inhibited in vivo thrombus formation with a 50% inhibitory bolus dose (ID50) of approximately 20 μg/kg, ex vivo ADP-induccd platelet aggregation with ID50 of 10 μg/kg, and bolus injection of 1 mg/kg prolonged the bleeding time from 38 ± 9 to 1,100 ± 330 s. Administration of TP9201 in hamsters inhibited in vivo thrombus formation with ID50 of 30 μg/kg, ex vivo platelet aggregation with an ID50 of 50 μg/kg and bolus injection of 1 mg/kg did not prolong the template bleeding time. In the dog eversion graft model, infusion of 100 μg/kg of G4120 over 60 min did not fully inhibit platelet-mediated thrombotic occlusion but was associated with inhibition of ADP-induccd ex vivo platelet aggregation and with prolongation of the template bleeding time from 1.3 ± 0.4 to 12 ± 2 min. Infusion of 300 μg/kg of TP9201 over 60 min completely prevented thrombotic occlusion, inhibited ex vivo platelet aggregation, but was not associated with prolongation of the template bleeding time.TP9201, unlike G4120, inhibits in vivo platelet-mediated thrombus formation without associated prolongation of the template bleeding time.

Significance of Platelet β-Adrenoceptors for Platelet Responses In Vivo and In Vitro

1992 ◽  
Vol 68 (06) ◽  
pp. 687-693 ◽  
Author(s):  
P T Larsson ◽  
N H Wallén ◽  
A Martinsson ◽  
N Egberg ◽  
P Hjemdahl
Keyword(s):  
Ex Vivo ◽  
High Dose ◽  
Platelet Aggregability ◽  
Adrenoceptor Agonist ◽  
Dose Infusion ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThe significance of platelet β-adrenoceptors for platelet responses to adrenergic stimuli in vivo and in vitro was studied in healthy volunteers. Low dose infusion of the β-adrenoceptor agonist isoprenaline decreased platelet aggregability in vivo as measured by ex vivo filtragometry. Infusion of adrenaline, a mixed α- and β-adrenoceptor agonist, increased platelet aggregability in vivo markedly, as measured by ex vivo filtragometry and plasma β-thromboglobulin levels. Adrenaline levels were 3–4 nM in venous plasma during infusion. Both adrenaline and high dose isoprenaline elevated plasma von Willebrand factor antigen levels β-Blockade by propranolol did not alter our measures of platelet aggregability at rest or during adrenaline infusions, but inhibited adrenaline-induced increases in vWf:ag. In a model using filtragometry to assess platelet aggregability in whole blood in vitro, propranolol enhanced the proaggregatory actions of 5 nM, but not of 10 nM adrenaline. The present data suggest that β-adrenoceptor stimulation can inhibit platelet function in vivo but that effects of adrenaline at high physiological concentrations are dominated by an α-adrenoceptor mediated proaggregatory action.

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