Energy devices

for all surgery students

1. ENERGY DEVICES IN SURGERY SURG LT CDR K S PATEL

2. Scope Types of Energy Devices Basics of electricity Basics of energy devices Application/uses Do’s and Don’ts while using them

3. Energy Devices Energy devices in surgery • Electrical / Radiofrequency Monopolar Bipolar • Ultrasonic Harmonic scalpel Thunderbeat •Vessel sealing technology •Cryosurgery • Laser

4. History Use of electrocautery (fire-drill) is described in ancient medicine 3000 BC In 1881, M orton: electric current in 100,000 Hz does not produce shock 1926-Cushing and Bovie made first electrosurgical generator

5. Basics of electricity Current-Flow of electrons during a period of time Circuit- pathway for uninterrupted flow of current Voltage-Force pushing current to a particular direction Resistance/Impedance

6. Temperature Vs Tissue Effect 45 degree C : collagen uncoils & may reanneal 60 degree C : irreversible protein denaturation coagulation necrosis begins 80 degree C : carbonization begin drying and shrinkage of tissues 90-100 degree C : complete cellular destruction by vapourization gas and smoke production

7. Electrosurgery Vs Electrocautery The terms electrocautery and electrosurgery are frequently used interchangeably; however, these terms define two distinctly different modalities. 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.

8. Electrosurgical devices Monopolar Bipolar

9. MONOPOLAR

10. Monopolar Most commonly used electrosurgical modality. The active electrode is in the wound. Patient return electrode is attached somewhere else on the patient. 4 components: generator, active electrode, patient, patient return electrode Produce variety of tissue effects depending on waveform

11. Tissue Effect Cutting Blending Fulguration Coagulation Desiccation

12. Waveform And Effect

13. Types Electrosurgical Generators two types of electrosurgical generators: • Ground referenced generators (typically older, outdated units) • Isolated generators (today’s state-of-art technology)

14. Grounded Electrosurgical

15. Grounded Electrosurgical Circuit is completed by grounded element/ earthing May use alternate pathway Causes thermal effect/burn

16. Isolated Electrosurgical

17. Isolated Electrosurgical In 1968,isolated generator technology revolutionized electrosurgery Circuit is completed by the generator, not by ground Current does not recognize grounded objects as pathways to complete the circuit Patient return electrode is recognized as preferred pathway Hazards of current division and alternate site burn are eliminated.

18. Complications R eturn electrode site burn A return electrode burn occurs when the heat produced, over time, is not safely dissipated by the size or conductivity of the patient return electrode

19. Do’s and Don'ts Proper/ full contact between body and return pad Conductive gel may be used Placed on the same side of surgery and near to it If metallic prosthesis-opposite side of body and near If prosthesis on both sides-than in between With vascular and muscle mass Avoid over bony prominences Common position-thigh, abdomen ,back

20. Patient return electrode monitoring technology -protects patient from pad site burn -monitor impedance at the patient/pad interface -system deactivate if impedance is high -such electrode can be identified by its split appearance i.e. two separate areas and a special plug with center pin

21. Direct Coupling When the active electrode touches another metal instrument. - The electrical current flows from one to the other and then proceeds to tissue resulting in unintended burn. - Do not activate the generator while the active electrode is touching a metal object or not in vision .

22. Capacitative coupling During MIS procedure, 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 wall.This current may exit to some adjacent tissue, result in significant injury Use the lowest power setting

23. Insulation Failure Insulation covering of an endoscopic instrument has been damaged Cracks or breaks in the shaft’s insulation allow the electrical energy to escape and burn unintended tissue. The insulation of endoscopic instruments must be inspected before, during and after each use Most damage to insulation occurs during instrument processing, specifically during sterilization. Heat with subsequent cooling causes insulation to shrink and then expand. During this process cracks and breaks can occur

24. Applied aspects Inspect insulation carefully Use lowest possible power settings Use a low voltage waveform(cut) Use brief intermittent activation vs prolonged activation Do not activate in open circuit Do not activate in close proximity or direct contact with other instrument

25. Use bipolar electrosurgery when appropriate Do not use hybrid canula . Select an all metal canula system as the safest choice. Active electrode monitoring system: to avoid problems of insulation failure and capacitive coupling

26. ULTRASONIC DEVICES Ultrasonic vibrations instead of electrical current Instrument blade vibrate at 55500 hz along the long axis Ultrasonic probe employ both compression and friction to deliver mechanical energy to target tissue Ultrasonic probe contain piezoelectric component, that converts electric energy into mechanical energy/heat Amino acids unwind and reshape and hydrogen bonds break resulting in protein denaturation and coagulum formation

27. Advantages Dual action-coagulation and cut Low heat generation No lateral tissue damage Better visual field-no smoke No current through patient Less tissue damage-less post op pain Precise dissection Disadvantage- Longer time for effect

28. THUNDERBEAT THUNDERBEAT is integration of both bipolar and ultrasonic energies delivered simultaneously from a single versatile instrument. benefits of each individual energy; the ability to rapidly cut tissue with ultrasonic energy; and the ability to create reliable vessel seals with bipolar energy .

29. CUSA( Cavitron ultrasonic surgical aspiration) Cavitation- Formation of Vapour by pressure reduction intead of heat. Utilizing a hollow titanium tip that vibrates along its longitudinal axis, fragmentation of susceptible tissue occurs while concurrently lavaging and aspirating material from the surgical site.  The CUSA selectively ablates tissues with high water content such as liver parenchyma, glandular, and neoplastic tissue. 

30. VESSEL SEALING TECHNOLOGY Combination of pressure and energy to create a seal. Feedback controlled output so reliable seal in minimal time Seal strength comparable to sutures/clips, can withstand >3 times normal SBP - ligasure : 0 - 4.5 mm - enseal : 1 mm

31. LigaSure Applies optimal pressure to vessel M easure initial resistance of tissue and chooses appropriate energy settings D elivers pulsed energy with continuous feedback control Senses that tissue response is complete and stops the cycle.

32. Cryosurgery Uses extreme cold is used to destroy diseased tissue Formation of ice crystels having lower density Impair blood circulation Cryopobe is placed via USG/MRI guided Liquid nitrogen/Argon gas Damaged tissue-naturally absorbed/scab formation