Presentation on theme: " Electrosurgery: use of electricity to cause thermal tissue destruction, most commonly in the form of tissue Dehydration coagulation vaporization."— Presentation transcript:
Electrosurgery: use of electricity to cause thermal tissue destruction, most commonly in the form of tissue Dehydration coagulation vaporization.
Electrodurgical procedures: Electrolysis : direct current induces tissue damage through a chemical reaction at the electrode tip Coblation: high-frequency alternating current ionizes an electrically conductive medium, usually isotonic saline solution, which transmits heat to cause superficial epidermal and dermal damage with minimal collateral tissue destruction.
High-frequency electrosurgery: in which tissue resistance to the passage of high-frequency alternating current converts electrical energy to heat, resulting in thermal tissue damage.
High Frequency Electodurgery : Heat generation occurs within the tissue, while the treatment electrode remains 'cold'. This method includes : electrodesiccation, Electrofulguration electrocoagulation electrosection.
Electrocautery: in which direct or high- frequency alternating current heats an element, which causes thermal injury by direct heat transference. Unlike electrosurgery, the element in electrocautery is hot
Electrical current : the net flow of electrons through a conductor per second, and is measured in amperes Current Density: the amount of current per cross sectional area (J=I/A)
The thinner the electrosurgical tip (i.e. decreasing the cross-sectional area of the conductor, A), the greater the current density, j, at the point of electrode contact.
High current density results in greater tissue injury, and is the basis of surgical diathermy
increasing the cross- sectional area of the electrode by a sufficient amount decrease current density to a level of nondestructive tissue warming.
Resistance : the ability of a conductor to impede the passage of an electric current, and is measured in ohms.
Notice risk factors of the procedure: excessive blood loss, such as bleeding diathesis, poor healing, such as vasculopathy, malnutrition, diabetes mellitus or poor general medical condition.
Identify : cardiac pacemakers or implantable cardiodefibrillators May dysfunction in the presence of electromagnetic radiations
All Jewelry should be removed Risk of burning For Prep use : nonalcohol prep solution (risk of ignite) Use chlorhexidine or povidone-Iodine
If work in the perianal Region: Use moist packing over anus to prevent ignition of methane
Monopolar v.s Bipolar is not correct for electrosurgery because we use alternating current : It is correct for electrolysis that use direct current
'mono-' and 'bi-' terminal : the number of treatment electrodes used in electrosurgery. Monoterminal indicates that only one electrode delivers current to the patien Biterminal indicates that two electrodes are used for this purpose.
Second electrode: an indifferent electrode, serving to complete an electrical circuit that begins in the electrosurgical unit, flows through the patient, and then returns to the unit.
electrodesiccation and electrofulguration, are monoterminal: electrons are dispersed randomly to the environment, electrocoagulation or electrosection, are biterminal.
Electrofulguration and electrodesiccation : use markedly damped, high-voltage, low-amperage current in a monoterminal fashion to produce superficial tissue destruction
Electrodesiccation: the electrode contacts the skin and superficial skin dehydration occurs as a result of Ohmic heating
Low power setting : Most damage is epidermal minimal risk of scarring Higher power settings: increasing dermal coagulation superficial scarring hypopigmentation.
variation of electrodesiccationin electrode is held 1-2 mm from the skin surface causes tissue dehydration by sparks
cause superficial epidermal carbonization. This carbon layer has an insulating effect and minimizes further damage to the underlying dermis. lesions treated by electrofulguration usually heal rapidly with minimal scarring
Because of their low amperage, electrodesiccation and electro fulguration are best suited for superficial and relatively avascular lesions, such as verrucae and seborrheic keratosis. Are not suitable for very vascular lesions
uses low-voltage, moderately damped or partially rectified, high-amperage current in a biterminal fashion to cause deeper tissue destruction and hemostasis with minimal carbonization High amperage causes deep tissue destruction and hemostasis.
In electrocoagulation, one applies and slowly moves the electrode across the lesion until slightly pink to pale coagulation occurs. A curette may then be used to remove the coagulum. avoid damaging tissue to the extent that a friable, charred coagulum results because this eschar may easily dislodge and result in delayed bleeding.
deep destruction provided by electrocoagulation results in scarring, and this should be noted when discussing therapeutic alternatives with the patient.
achieve hemostasis by touching the electrode directly to the bleeding vessel, or by using biterminal forceps. With either method, the heat generated seals the vessel by fusion of its collagen and elastic fibers, and the operative field must be dry for maximal efficacy. It is useful for vascular lesions such as PG
Electrosection uses undamped or slightly damped, low voltage, high-amperage current in a biterminal fashion to vaporize tissue with minimal peripheral heat damage. Undampedcurrent yields cutting without coagulation, whereas slightly damped current provides some coagulation.
electrosection requires almost no manual pressure from the operator because the electrode glides through tissue with minimal resistance. If sparking occurs, the power setting is likely too high. If the electrode drags, the power setting is likely too low.
Advantages of electrosection are its speed and its ability to simultaneously cut and seal bleedin vessels, for instance, in the excision of large, relatively vascular lesions, such as acne keloidalis nuchae and rhinophyma.
uses low-voltage, high-amperage, direct or alternating current to heat a surgical tip to cause tissue desiccation, coagulation, or necrosis by direct heat transference to tissue. is excellent for pinpoint hemostasis and is compatible with patients who may not tolerate current flow (e.g. pacemaker patients).
Choice depends on the: understanding of the nature of the destructive modality, lesional histology anticipated consequences, including pigmentary change and scarring
use the minimum power setting necessary to achieve the desired effect Excessive power causes disproportionate tissue damage, and is associated with complications such as increased fibrosis, susceptibility to wound infection, and delayed wound healing.
treatment electrode should always be clean of carbonized tissue, which decreases current density and insulates against current flow, thereby reducing cutting and coagulation effect. If carbon build-up seems rapid and excessive, the power setting may be too high, or the procedure rate too slow.
often useful to combine routine electrosurgery with other surgical modalities (e.g. use of a scalpel, curette or scissors to remove the bulk of a large lesion before use of electrosurgery to treat the base).
Hemostasis should be reserved for vessels < 1 mm in diameter; larger vessels or arterioles have a greater chance of delayed bleeding and should be ligated with a dissolvable suture.
the operative field should be dry because current flowing from the electrode is diffused by blood. apply the minimum amount of time and power, as well as to clamp only the minimum amount of tissue necessary to seal the vessel
Another problem during electrocoagulation is an apparently sudden decrease in power. Instead of increasing the power setting: confirm good contact between the indifferent electrode and the patient to ensure adequate current drainoff, and that the electrosurgical tip is clean.
Incisions made with electrocoagulation should be avoided because animal studies demonstrate: they are associated with higher postoperative infection rates than incisions made with a scalpel or with electrosection
a needle electrode often provides the most precise cutting effect. Larger electrodes, such as blades and loops, require greater electrical energy to produce the same cutting effect, causing greater peripheral tissue destruction, which may impair wound healing.
For debulking procedures, such as rhinophyma excision, however, wire loop electrodes may be used to remove tissue efficiently For specimens requiring histopathologic analysis, cutting without coagulation should be used.
Reports of impaired wound healing and increased postoperative infection rates associated with early model electrosection units have discouraged the widespread use of electrosection for skin incision.
modern electrosection units provide superior speed hemostasis cosmetic outcome, and decreased postoperative pain than conventional scalpel surgery, while providing comparable postoperative wound healing and infection rates.
Superficial electrosurgical wounds heal well by second intention with basic wound care principles-specifically, cleansing with hydrogen peroxide or saline daily followed by application of an antibiotic ointment and protective dressing.