electrosurgery & gyn surgery: get the point across m. jonathon solnik, md, facog facs director,...
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Electrosurgery & Gyn Surgery:Get the Point AcrossM. Jonathon Solnik, MD, FACOG FACSDirector, Minimally Invasive Gynecologic SurgeryDept OB/Gyn, Cedars-Sinai Medical CenterAssistant Clinical ProfessorDept OB/Gyn, David Geffen School of Medicine at UCLA
Whats the difference ?Electrocautery: use of a direct electrical current to heat up a metal conductor with a high impedance to flow so that the metal becomes physically hot.
Electrosurgery: manipulation of electrons through living tissue using an alternating current with enough concentration to create heat within the tissue and cause destruction.
Electrosurgical Generator (ESU)Machine that creates an alternating current with enough current density (concentration) to heat and destroy tissue Sinusoidal waveform that is bidirectionalThe waveform can be altered to createdifferent surgicaleffectsRadio Frequency (RF)The frequency (>100 kHz) is above that which stimulates muscle or nerve
Look Familiar ???
How is tissue destroyed ?Electric energy is converted to heat (no net change)Each waveform passes through both positive and negative peaks the intracellular polarity is interrupted, creating cellular heat.
Odell RC. Surgical Energy Sources 2002
44-50 C50-80 C80-100 C100-200 C>200 CVisibleNoneBlanchingShrinkageSteamCarbonizedDelayed NecrosisSloughingSloughingUlcerationCraterMOAMetabolismDenatureDesiccateVaporizeCombust
WaveformsCUT Continuous Simple UndampedHigh currentLow VoltageRapid tissue heating vaporizationNon-contact Less thermal spread
COAGIntermittent Cooling effectDampedLower currentHigher voltageLess cellular heatContact or non-contactRisk of thermal injury
CUT WaveformBLEND Interrupted CUT current with increasing VoltageBlend of surgical effectsReduced current/time1 more cut / 3 more coagImproved hemostasis Requires more time to CUT
COAGULATIONFulguration (COAG)Non-contact Coagulates by sprayingHeat lost to airSuperficial eschar carbonization (HOT)Oozing surfacesMinimal depth of necrosis (0.5-2mm)Stop when bleeding stops
Desiccation (CUT>COAG) Contact All heat transmitted to tissue Deep & wide tissue necrosisDiscrete bleederGaps in hemostasis - can spark thru coagulated tissue bipolar betterElectrode can stick to tissue as it heats
Electrode-Surface InterfaceTemperature at which the current heats the tissue is directly related to the size of the electrode and how it contacts the tissue Temperature = (i x 2 / r x 4) X R x tSmall electrode (r) HOTDispersive electrode (grounding pad) minimal tissue changeHigh tissue tension (R) affects tissue resistance
Video CUT vs. COAG
Monopolar vs. Bipolar Current
Resectoscope LoopUltra-fineVapor pocketElectrons do the workVapotrodesaggregation of electronsMonopolarnonconductive, unchargedBipolardoesnt matter
Thermal Injuries in MISActive electrodes can be longTrue visual field is limited -- flying blind !!!Delayed Presentation73% of injuries after L/S chole went unrecognized13-10 days or longer2Evaluate pain, urinary retention, nausea or feverSLS Survey 199513% of surgeons had at least 1 malpractice caseTucker RD, et al. AORN J 1995Reich H. Surg Laparosc Endosc 1992
The probability of incurring a thermal injury during operative hysteroscopy increases with monopolar energy.
Hazards of ElectrosurgeryZAP !!Direct injury with active electrode These are high energy burnsAlternate Ground BurnsDivision of current ECG leadsIsolated ground circuitryPatient Return Electrodes (dispersive)Previously accounted for 70% of injuriesThe large size Low conductivity Interpolated REMPlacement
Capacitative CouplingThis phenomenon cannot be eliminatedAbdominal wall often serves as a return to groundPlastic cannulas may not provide more protection than metal cannulas
Tucker RD, et al. AORN J 1995Reich H. Surg Laparosc Endosc 1992
Which setting should be used when resecting an intracavitary myoma?Bipolar resectoscope using Blend 2Monopolar resectoscope using pure CUTMonopolar resectoscope using pure COAGBipolar resectoscope using pure COAG
Insulation FailureInstantaneous burns with HIGH-power densityOften occur in Zone 2 (outside of surgical field)Can occur repeatedly causing serious injury
Prevention, prevention, preventionKnow and inspect your instrumentsAdjust power according to desired effectUse a low voltage waveform (CUT)Use short & controlled burstsPractice skill sets in the lab
*Blend 1 lower voltage, shorter time-outsBlend 2 higher voltage, longer time-outs*Blend 1 lower voltage, shorter time-outsBlend 2 higher voltage, longer time-outs*With desiccation, be patient it takes time for the larger electrode and smaller power density to create its effect. If you increase the energy, you may have more sticking and more sparking resulting in fulguration (which stops the deep tissue process).