Fundamental Use of Surgical Energy Abul Fazal Ali Khan

The need to discuss this topic Do you consider yourself an energy expert? Can you assemble your favourite device? Have you ever been associated with an injury from an energy device? Have you ever used an energy device without prior training or reading the instruction manual?

Almost all surgical procedures include the use of energy device

Complications Patient burns OR fires Interference with other devices

Basic Electrosurgical unit

ELECTROCAUTERY IS NOT ELECTROSURGERY Electrocautery: use of electricity to heat an object that is then used to burn a specific site e.g. a hot wire Electrosurgery: the electrical current heats the tissue. The current must pass through the tissue to produce the desired effect..

ELECTROSURGICAL TISSUE EFFECTS Cutting: divide tissue with electric sparks that focus intense heat at surgical site -By sparking we achieve maximum current concentration Fulguration: sparking with coagulation waveform -coagulates and chars the tissue over a wide area, result in coagulum -high voltage coag current is Desiccation: occurs when electrode is in direct contact with the tissue --Achieved most efficiently with cutting current --by touching electrode to the tissue, current concentration reduced, result in less heat and no cutting action --cells dry out and form a coagulum

We can cut with coag current and coagulate with cutting current. Benefit of coagulating with cutting current is that we use far less voltage. it has important implications in MIS

SAFETY CONSIDERATIONS Direct Coupling occurs when the active electrode touches another metal instrument. This can also occur if an active electrode is activated while in contact with a metal clip.

INSULATION FAILURE can occur when the insulation covering of an endoscopic instrument has been damaged allowing the electrical energy to escape and burn unintended tissue

Capacitive coupling an inadvertent capacitor may be created by the surgical instruments An electrostatic field created b/w two conductors, resulting induced current in second conductor Hybrid cannula are worst , metal part will create a capacitor but plastic anchor will prevent the current from dissipating through abd

BIPOLAR ELECTROSURGERY The two tines forceps function active and return electrodes. Only the tissue grasped is included in circuit. No patient return electrode Better hemostasis Less thermal injury Safer than monopolar

VESSEL SEALING TECHNOLOGY Combination of pressure and energy to create a seal. Feedback controlled output so reliable seal in minimal time Seals vessels up to 7 mm with a single activation. Seal strength comparable to sutures/clips, can withstand >3 times normal SBP

ULTRASONIC ENERGY DEVICES employ both compression and friction to deliver mechanical energy to target tissue Amino acids unwind and reshape and hydrogen bonds break resulting in sticky coagulum Ultrasonic shears contain piezoelectric diskes, that converts electric energy into mechanical energy which is amplified by silicone element Instrument blade vibrate at 55500 hz along the long axis Safely coagulates and transect vessels upto 5 mm

ULTRASONIC ENERGY DEVICES provide excellent hemostasis efficient transection minimal lateral thermal damage low smoke generation no risk of electrical current passage to the patient

Other Options Thunderbeat CUSA Argon enhanced electrosurgery