Electrosurgery & Gyn Surgery: Get the Point Across M. Jonathon Solnik, MD, FACOG FACS Director, Minimally Invasive Gynecologic Surgery Dept OB/Gyn, Cedars-Sinai Medical Center Assistant Clinical Professor Dept OB/Gyn, David Geffen School of Medicine at UCLA

What’s 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 bidirectional The waveform can be altered to create different surgical effects Radio 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. 44-50 C 50-80 C 80-100 C 100-200 C >200 C Visible None Blanching Shrinkage Steam Carbonized Delayed Necrosis Sloughing Ulceration Crater MOA Metabolism Denature Desiccate Vaporize Combust Odell RC. Surgical Energy Sources 2002

Waveforms CUT COAG Continuous Simple Undamped High current Low Voltage Rapid tissue heating  vaporization Non-contact Less thermal spread COAG Intermittent Cooling effect Damped Lower current Higher voltage Less cellular heat Contact or non-contact Risk of thermal injury Blend 1 – lower voltage, shorter time-outs Blend 2 – higher voltage, longer time-outs

CUT Waveform BLEND Interrupted CUT current with increasing Voltage Blend of surgical effects Reduced current/time 1 – more cut / 3 – more coag Improved hemostasis Requires more time to CUT Blend 1 – lower voltage, shorter time-outs Blend 2 – higher voltage, longer time-outs

COAGULATION Fulguration (COAG) Desiccation (CUT>COAG) Non-contact Coagulates by ‘spraying’ Heat lost to air Superficial eschar – carbonization (HOT) Oozing surfaces Minimal depth of necrosis (0.5-2mm) Stop when bleeding stops Desiccation (CUT>COAG) Contact All heat transmitted to tissue Deep & wide tissue necrosis Discrete bleeder Gaps in hemostasis - can spark thru coagulated tissue – bipolar better Electrode can stick to tissue as it heats 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).

Electrode-Surface Interface Temperature 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 t Small electrode (r) – HOT Dispersive electrode (grounding pad) – minimal tissue change High tissue tension (R)– affects tissue resistance

Video – CUT vs. COAG

Monopolar vs. Bipolar Current

Resectoscope Loop Ultra-fine Vapor pocket Electrons do the work Vapotrodes aggregation of electrons Monopolar nonconductive, uncharged Bipolar doesn’t matter

Thermal Injuries in MIS Active electrodes can be long True visual field is limited -- flying blind !!! Delayed Presentation 73% of injuries after L/S chole went unrecognized1 3-10 days or longer2 Evaluate pain, urinary retention, nausea or fever SLS Survey 1995 13% of surgeons had at least 1 malpractice case Tucker RD, et al. AORN J 1995 Reich H. Surg Laparosc Endosc 1992

The probability of incurring a thermal injury during operative hysteroscopy increases with monopolar energy. True False

Hazards of Electrosurgery Direct injury with active electrode These are high energy burns Alternate Ground Burns Division of current  ECG leads Isolated ground circuitry Patient Return Electrodes (dispersive) Previously accounted for 70% of injuries The large size Low conductivity Interpolated REM Placement ZAP !!

Capacitative Coupling This phenomenon cannot be eliminated Abdominal wall often serves as a return to ground Plastic cannulas may not provide more protection than metal cannulas Tucker RD, et al. AORN J 1995 Reich H. Surg Laparosc Endosc 1992

Which setting should be used when resecting an intracavitary myoma? Bipolar resectoscope using Blend 2 Monopolar resectoscope using pure CUT Monopolar resectoscope using pure COAG Bipolar resectoscope using pure COAG

Insulation Failure Instantaneous burns with HIGH-power density Often occur in Zone 2 (outside of surgical field) Can occur repeatedly causing serious injury

Prevention, prevention, prevention Know and inspect your instruments Adjust power according to desired effect Use a low voltage waveform (CUT) Use short & controlled bursts Practice skill sets in the lab