The document discusses various energy sources used in surgery including electrical, ultrasonic, argon beam, and laser energies. It provides details on electrosurgery modalities like electrocautery and electrosurgery. Newer advanced bipolar devices like Ligasure, Gyrus ACMI, and Enseal are described which provide vessel sealing through thermal coagulation. Ultrasonic devices like Harmonic scalpel use high frequency vibrations for vessel sealing and precise dissection. Other technologies discussed include argon beam coagulation, CUSA, microwave ablation, and radiosurgery. Patient safety considerations are highlighted for different energy sources.

1. ENERGY SOURCES IN SURGERY
Dr. Ankur

2. HISTORY OF ENERGY SOURCES

3. HISTORY LESSON
• The first electrosurgical unit was developed in 1926 by Dr.
Harvey Cushing (a neurosurgeon) and Dr. William Bovie, a
Harvard physicist
• Since then the name “Bovie” has been associated with
electrosurgical unit.

4. BASIC FORMS OF ENERGY
4 forms –
1. Electrical
2. Ultrasonic
3. Argon Beam
4. Laser

5. ELECTROCAUTERY AND ELECTROSURGERY
• The terms electrocautery and electrosurgery are frequently
used interchangeably; but these terms define two distinctly
different modalities.
• In electrocautery, Only the heated wire comes in contact with
tissue.
• In electrosurgery, the patient is included in the circuit and
current enters the patient’s body to vaporize or coagulate
tissue.

6. TEMPERATURE VS TISSUE EFFECTS
45 degree C: collagen uncoils, reversible
60 degree C: irreversible protein denaturation,
coagulation necrosis
80 degree C: drying and shrinkage of tissues
90-100 degree C: vaporization
125degree C: complete oxidation carbon residue &
eschar formation

7. ELECTROSURGERY
• CUT
• COAGULATE
• DISSECT
• FULGURATE
• ABLATE

8. ELECTROSURGICAL GENERATOR
• Converts a 60 cycles/sec (60 Hz), low voltage alternating current into higher
voltage and increases the frequency to over 300,000 cycles per second.
• nerve and muscle stimulation cease at 100,000 cycles/second (100 kHz),
electrosurgery can be performed safely at “radio” frequencies above 100 kHz.
• At this frequency electrosurgical energy can pass through the patient with
minimal neuromuscular stimulation and no risk of electrocution.

9. SYSTEM COMPONENTS:
1. Generator (electrosurgical unit)
2. Inactive dispersive electrode (grounding pad)
3. Active electrode (“Bovie” pencil)

10. TYPES OF ESU UNITS
• Monopolar
• Bipolar
(Some ESU units have both monopolar & bipolar capability)

11. MONOPOLAR ESU
• Electrical energy flows from the generator (ESU unit), to the active electrode (cautery pencil).
• The energy then passes through the patient to the dispersive cautery pad, thus completing
the electrical circuit.

12. MONOPOLAR ELECTROSURGERY
• Most commonly used electrosurgical modality.
• Produce variety of tissue effects depending on waveform.
a) Cutting.
b) Coagulation and fulgration.
c) Dessication

13. ELECTROSURGICAL TISSUE EFFECTS
1) Cutting: -
-Cutting depends on the production of a
continuous sine wave of current
-Duty cycle(“on” time) is high,
-vaporize tissue
2) Fulguration:
-coagulates and chars the tissue over a wide
area, result in coagulum
-high voltage current is used(duty cycle 6%)
-intermittent waveform

14. 3) Desiccation:
--occurs when electrode is in direct contact with the tissue
--Achieved most efficiently with cutting current
4) Blend
--A “blended current” is not a mixture of both cutting and coagulation current but
rather a modification of the duty cycle. Tissue is heated and water in the cell dries out.
Can use cutting or coagulation current by contact with tissue.
--As we go from Blend 1 to Blend 3 the duty cycle is progressively reduced.
-- A lower duty cycle produces less heat. Consequently, Blend 1 is able to vaporize
tissue with minimal hemostasis whereas Blend 3 is less effective at cutting but has
maximum hemostasis

16. VARIABLES IMPACTING TISSUE EFFECT
-Waveform
-Power settings
-Size of electrode
-Time
-Manipulation of electrode
-Type of tissue

17. MONOPOLAR
• ADVANTAGES
• Ease of use
• Cutting and coagulation currents
• Dissecting capability.
• DISADVANTAGES
• Larger volume of tissue injured.
• Interferes with electrical implants.
• Requires ground pad.

18. BIPOLAR ELECTROSURGERY
• active and return electrodes are in the same surgical
instrument
• The electrical current is confined to the tissue between the
tines of The bipolar forceps
• Only the tissue grasped is included in circuit.
• Better hemostasis
• Less thermal injury

19. • ADVANTAGES.
• Small volume of tissue injured.
• No patient return electrode.
• Safe with electrical implants.
• Effective in wet fields.
• Decreased thermal injury to surrounding tissues
• Decreased risk of capacitive coupling injuries

20. DISADVANTAGES
• More skill required.
• Coagulation only.
• No dissecting capability

22. BEST GROUNDING PAD SITE
• Over a well-vascularized muscle mass
• Avoid placing grounding pad over bony prominences, hairy
sites, scar tissue,excess adipose tissue

23. PLACING GROUNDING PAD
• Grounding pad should be placed so that the entire surface of the pad is in
uniform contact with the pad site
• Avoid any tenting or gaps where parts of the pad are not in contact with the
patient

24. SAFETY CONSIDERATIONS DURING MIS
Direct Coupling
• Occurs 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.
• So, do not activate the generator while the active electrode is touching a metal
object or not in vision.

25. INSULATION FAILURE
• Insulation failure can occur when the
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 nearby tissue.
• Most damage to insulation occurs
during instrument processing,
specifically during sterilization

26. CAPACITIVE COUPLING
• Capacitive coupling is electric current that is established in tissue or in metal
instrument running parallel but not directly in contact with the active electrode.
• Hybrid cannula are worst , metal part will create a capacitor but plastic collar 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.
• Keep the electrode eschar free
• Use larger diameter trocars and smaller diameter electrodes

27. PATIENT RETURN ELECTRODE MONITORING TECHNOLOGY
• -Protects patient from pad site burn
• -Monitor impedance at the patient/pad interface
• -System deactivates 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.

28. ACTIVE ELECTRODE MONITORING SYSTEM
• Shielded and monitor instruments continuously and direct stray
energy, away from the patient via a protective shield.
• When insulation failure occurs or capacitively coupled energy
reaches dangerous levels, the electrosurgical unit (ESU) shuts
down automatically and sounds alarm
• AEM system detects even the smallest full thickness insulation
breaks on Laparoscopic instruments, virtually eliminating
accidental burns and reducing the possibility of patient injury.

29. RECOMMENDATIONS TO AVOID ELECTROSURGICAL COMPLICATIONS
IN MIS
• 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
• Use bipolar electrosurgery when appropriate
• metal canula system as the safest choice.
• Active electrode monitoring system.

30. NEWER ENERGY SOURCES

31. NEWER ENERGY SOURCES
• Advanced Bipolar devices.
• Gyrus ACMI (Olympus)
• Enseal (Ethicon Endo-Surgery)
• Ligasure (covidien)
• Ultrasonic scalpel
• Harmonic ACE( Ethicon Endo-Surgery)

32. LIGASURE
• “Electrosurgical collagen welding” combination of pressure and energy 
denature collagen and elastin  permanent seal.
• Delivers high current and low voltage along with pressure from jaws
• Hydrothermal rupture of collagen cross links
• 60-90 degree C.

33. • Average seal cycle is 2-4 sec.
• Seal can withstand upto 3 times SBP.
• Can ligate vessels upto 7 mm.
• Lateral thermal spread : 2mm
• Energy delivery cycle: computer algorithm adjust current and
voltage based on real time measures of tissue impedence.
• Feedback controlled response system-- senses that tissue
response is complete and stops the seal cycle.

34. •.
Advantages

35. GYRUS ACMI
• Generates low voltage and high current in pulses
and is based on vapour pulse coagulation.
• Plasma kinetic energy delivered in pulses
• Intermittent tissue cooling prevents thermal damage
and sticking.
• 2 modes
• Vapor pulse coagulator
• PK (plasma kinetic)cutting
PK energy to tissue  forms vapour zones
current passes around the vapour zone vapour
zone collapses causing tissue sealing

36. ENSEAL RF SYSTEM
- Adjust dose energy simultaneously according to the impedence of tissue.
- Smart electrode technology- millions of nano conductive particles each with discrete
thermostatic switch in temperature sensitive material.
- sealing arteries, veins ,transecting adipose tissue, ligaments & connective tissue.
• Less heat required. Tissue volume reduced by compression.
• Vessel walls fused by compression, protein denaturation and then renaturation.
• Seals upto 7 mm vessels. Thermal spread 1 mm.
• Withstands upto 7 times systolic pressures.

37. • .

39. ULTRASONIC DEVICES
• Use high frequency vibrations
• Harmonic – for delivering precise energy for better vessel
sealing capabilities
- upto 7mm vessels
• Harmonic Scalpel – Vessel sealing & transecting capabilities
• Work at 55KHz

40. HARMONIC SCALPEL
• Converts ultrasonic energy→
mechanical energy.
• Piezoelectric crystal produces ~55000 vibrations per second.
• Lysis of H-bond → heat → denaturation of protien → separation of tissue.
• Tissue separation at 50-60 degree C.

41. TYPES OF HARMONIC SCALPELS
• ACE curved sheers
• Coagulating sheers
• Harmonic focus
• Dissecting hook

42. ADVANTAGES OF HARMONIC SCALPEL
• Minimal thermal spread.
• No dessication or charring of tissue.
• No risk of electrical injury
• No smoke.
---Clipless lap cholecystectomy uses a harmonic scalpel.

43. DISADVANTAGES OF HARMONIC SCALPEL
• Inability to coagulate vessels greater than 5mm.
• Operator dependence of settings of the blade according to tissue.
• Increased cost.

45. ULTRASOUND DISSECTOR
• Uses high-frequency mechanical vibrations to fragment tissue
• Used in ophthalmic, neuro, hepato-biliaryand oncologic cytoreductive surgery
• Fragments tissues by contact with high water content cells
• Vibration generates vapour pockets within the cells that lead to disruption and
fragmentation.

46. ULTRASONIC KNIFE
• Produces vibrations at 55.5KHz at the tip of the blade via a hand piece transducer
• The moving blade couples with the tissue resulting in breakage of protein hydrogen
bonds and thus protein coagulum forms.
• Can perform cutting and heamostasis with minimal damage
• Limited lateral spread and thermal injury
• No electrical energy transferred to patients

48. THUNDERBEAT
• THUNDERBEAT -- both bipolar and ultrasonic energies
• Ultrasonic energy: for cut
• Bipolar energy: for vessel seal

49. ADVANTAGES
-RELIABLE 7 MM VESSEL SEALING.
-MINIMAL THERMAL SPREAD.
-FASTEST IN-ITS-CLASS CUTTING.
-IMPROVED VISIBILITY.
-FINE DISSECTION.
-ALWAYS AVAILABLE BIPOLAR ENERGY FOR HEMOSTASIS

51. ARGON BEAM COAGULATION
Uses coaxial flow of argon gas to conduct monopolar current to the target
tissue.
Principle:
argon is an inert gas i.e easily ionised by electric current, when ionised
argon gas becomes far more conductive. And current arcs along the
pathway of ionised gas which is heavier than both O2 and nitrogen.

52. ADVANTAGES
COAGULATION WITHOUT DIRECT CONTACT OF ELECTRODE.
LESS SMOKE AND LESS ODOR.
LESS TISSUE DAMAGE.
DISADVANTAGES
CANNOT PRODUCE CUTTING EFFECT.
OVERHEAT.

53. USES
• Wide area of tissue
• Dissecting very vascular organs

55. CAVITRON ULTRASONIC SURGICAL ASPIRATOR (CUSA)
-work on many of the same principles as ultrasonic scalpels.
-CUSA is a dissecting device that uses ultrasonic frequencies at 23 kHz or
36 kHz.
-Used in liver surgery and neurosurgery

57. • Harmonic scalpel has the least thermal spread.
• Ligasure is the highest rated.
Sealing time (s) Burst pressure (hg
mm)
Smoke/visibility
(ppm)
Harmonic scalpel 14.3 204 2.88 ppm
Ligasure V 10 385 12.5 ppm
Gyrus PK 11.1 290 74.1 ppm
Enseal 19.2 255 21.6 ppm

58. LASER
• Precise application of energy.
• Less lateral damage and stray currents.
• Energy induces molecular vibration and thermal vibrations.
• Lasers primarily being used for surgery
- Carbon Dioxide
- Nd:YAG (Neodymium-doped Yittrium Aluminium Garnet)
- Argon
- Ho:YAG (Holmium-doped Yittrium Aluminium Garnet)
- KTP (Potassium Titanyl Phosphate)
- Diode

59. EFFECTS
• PHOTOCHEMICAL EFFECT AKA PHOTODYNAMIC THERAPY
• PHOTOABLATIVE EFFECT
• PHOTOTHERMAL EFFECT
• PHOTOMECHANICAL EFFECT

60. MICROWAVE ABLATION
• Generator probe at 2.4 GHz.
• Created alternating electrical field induces motion of polar molecules
kinectic energy converted into heat  coagulation necrosis.
• Applications – liver, prostatic hyperplasia, endometrial bleeding, partial
nephrectomy.
• Only small area ablated.

61. RADIOSURGERY
• Gamma knife used in neurosurgery.
• High energy gamma radiation arranged in circular fashion.
• Focussed stereotactically

62. SPECIAL CONSIDERATIONS: PATIENTS
WITH--
• Implanted pacemaker
• Implanted automatic defibrillator
• Cochlear Implant
• Implanted Bone Growth Stimulator
• Body Jewellery.
• Offender monitoring ankle bracelets
• Orthopedic implants (total hips, etc)

63. THANK YOU