This document discusses various energy sources used in surgery including radiofrequency electro-surgery, ultrasonic energy systems, lasers, and argon beam coagulation. It provides details on how each system generates energy and its corresponding tissue effects. Monopolar and bipolar electro-surgery are compared in terms of advantages and disadvantages. Harmonic scalpels are noted to have reduced thermal spread and overall procedure time compared to other devices. Risks such as burns and device interference are also reviewed.

2. Energy Sources
1. Radiofrequency Electro-surgery
• Monopolar cautery
• Bipolar cautery
2. Ultrasonic Energy System
• Harmonic scalpel
3. Laser
4. Argon Beam Coagulation

3. Radiofrequency electro-surgery

5. Electrosurgi
cal Unit
Produce AC
current
Delivered to
Pt. tissue by
Monopolar/
Bipolar
Instrument
Intracellular
Conversion
of Energy
Electromagnetic
Energy
Kinetic Energy
Thermal
Energy
Produce One of
the following
effects
1) Vaporisation
2) Fulgration
3) Desiccation
&Coagulation
Why AC current ?
Principle : Ohm’s Low
Depend on Heat
produced

6. In RF electro-surgery….
• V difference –
Produced by Electro-
surgical Unit
• R (resistance) –
By tissue

7. • More fatty tissue and
fibrous tissue provide
more Resistance… more
duration / more Voltage
difference is needed for
the same effect.

8. • Mainly 3 Components
Electromagnetic
Generator
Current : AC
Tissue Effect

9. Input : 50 Hz
Output : 500,000 Hz

10. Cut
• Low Voltage + Long Time
Pure Cut

11. Coag
• High Voltage + Short Time

12. In AC current, there is no net flow of electron through Patient… So, less chance of
Electrocution.

14. To & Fro movement of Electron
Electrical energy is converted to
Kinetic Energy
Kinetic energy produces Heat

15. 370
500
60-900
>1000
Cellular Vaporisation
Instant Cell Death : Coagulation
We are using the same frequency, then
how to generate diff amount of heat ?

16. We are using the same frequency, then
how to generate diff amount of heat ?
Current Density
Surface Area
Current Flow
Thermal Change ~ (Current Density)2

17. We are using the same frequency, then
how to generate diff amount of heat ?
Border
Less surface area
With same Hz –
more kinetic energy
Cut

18. We are using the same frequency, then
how to generate diff amount of heat ?
Side
More surface area
With same Hz –
less kinetic energy
Coagulation

19. We are using the same frequency, then
how to generate diff amount of heat ?
Thermal Change = K × (J)2 × R × T
= K × (I/A)2 × R × T
So, we can increase Temperature by
1. Increasing Current flow (I)
2. Decreasing Surface area (A)
3. Increasing Resistance (R)
• Continuous draining fluid
• Increasing tissue tension
4. Increasing Time (T)

20. Instruments
Monopolar Bipolar

21. • Using a pencil instrument, the
active electrode is placed in the
entry site and can be used to cut
tissue and coagulate bleeding.
• The return electrode pad is
attached to the patient, so the
electrical current flows from the
generator to the electrode
through the target tissue, to the
patient return pad and back to
the generator.

22. • Monopolar electro surgery can
be used for several modalities
including
1. cut,
2. blend,
3. desiccation, and
4. fulguration.

23. Advantages
• Easy to use
• Multiple modalities
• Adjust current density
• Inexpensive
• Easily available
• Best method for making simple
incisions on the skin
Disadvantages
• Interference with pacemakers
and other equipments during
surgery.
• Higher temperatures at the tool
tip and longer cool down times
to a safer temperature compared
to other energy based devices.
• Large thermal spread.

25. • electrons flow between two
adjacent electrodes. The tissue
between the two electrodes is
heated and desiccated.
• Less chances of Cutting
• Best for coagulation, so mainly
for small vessel coagulation
without thermal injury.

26. • Bipolar electro surgery uses
lower voltages so less energy is
required. But, because it has
limited ability to cut and
coagulate large bleeding areas,
it is more ideally used for those
procedures where tissues can
be easily grabbed on both sides
by the forceps electrode.

27. Advantage
• Better control over the area being
targeted, and helps prevent damage
to other sensitive tissues.
• The risk of patient burns is reduced
significantly.
• can be used in patients with
implanted devices to prevent
electrical current passing through
the device causing a short-circuit or
misfire.
• Good for coaptive vessel sealing
Disadvantage
• Operational time is usually longer
than monopolar electrosurgery
• Not as effective on small blood
vessels.

29. According to AORN journal (AORN - Association of perioperative Registered
Nurses)
• Around 40,000 pts. burned by faulty Electro-Surgical Unit
every year.
• 70% of them are undiagnosed at the time of surgery.

30. Mechanical Injuries
Dispersive Electrode
• Application site issue
• Partial detachment
Current diversion
• Insulation failure
• Direct coupling
Active electrode injury
• Inadvertent activation
• Direct extension

31. OT fire
• Triad of Cause leading to OT fire are…..
Heat

33. Ultrasonic Energy System

34. Ultrasonic
Generator
Electric
Current
Tissue Effect
Min Max
piezoelectric
transducers
Electric to Ultrasound

35. • Infrasonic < 20 Hz
• Audible wave = 20- 20,000 Hz
• Ultrasonic > 20,000 Hz
Ultrasonic Wave
Transmit from
Liquid/ Solid media
Produce Mechanical
Energy by Motion in
media

36. • We can set power level
1 To 5
Power Level
Level 5
100%
displacement =
100 micron
displacement
Level 1
50%
displacement =
50 micron
displacement

37. • Min Setup > 50 micron
Coagulate
• Max Setup ~ 100 micron
Cut

38. • Cutting
• Coagulation
• Cavitations : Motion of blade create Vaporization.
Fluid vapor expansion causes layers to separate
which enhance Plane of dissection
• Drilling

39. Advantages
• Produces less heat compared to
other energy devices (less than
80° C compared to 100° C for
electro surgery) thereby reducing
the risk of thermal injury.
• Does not transmit active current
in the tissues and thereby
eliminate any risk of electric
shock.
Disadvantage
• slower coagulation compared to
electrosurgery
• not as efficient in sealing medium
to large sized blood vessels. Not
reliable in sealing vessels larger
than 3mm.
• Produces high blade temperatures
and can damage adjacent tissues
or organs when come in contact
immediately after switched OFF

40. Harmonic Scalpel

41. 0
2
4
6
Thermal Spread
Ultrasonic
Bipolar
Monopolar

42. Ultrasonic Bipolar Monopolar
Coagulation Yes Yes Yes
Small vessel coagulatn Yes No ?
Large vessel coagulatn No Yes ?
Cutting Yes No Yes
Lateral Thermal Effect Lowest Medium Highest
Thermal Injuries Lowest Medium Highest

43. Laser

44. Laser means
concentrated beam
of light
Amount of energy
transmitted by the
light waves are then
absorbed by the
tissue
That Produce heat
According to amount
of Heat generated..
Tissue effect
Cut/ Coagulation

45. https://www.youtube.com/watch?v=1LmcUaWuYao

46. https://www.youtube.com/watch?v=1LmcUaWuYao

47. • Amount of heat produced depends on…
1. The power or intensity of a laser –
 measured in terms of ‘irradiation’ defined as the
ratio of power applied to the spot-size (cross
sectional area) of the laser beam (W/m2).
2. time of exposure
3. wave length (or frequency)

48. LASER
Photo-thermal
effect
The use of lasers to
generate heat for
destroying tumors
Photo-chemical
effect
Amount of irradiance is so
low
Instead of generating
heat, it induces chemical
reactions in the cells thus
causing inactivity

49. Lasers
Nd:YAG (1064 nm)
Skin Cancer
Thyroid Nodule
BPH treatment
TURP
Glaucoma & Posterior
capsular Cataract
Helium:Neon laser Argon Laser
Trabaculotomy
Trabaculoplasty
Panretinal
Photocoagulation
Argon:Floride (193 nm)
Photoablation
(LESIK)

50. Advantages
• Most widely used in
gynecological procedure because
of precise control of amount and
depth of tissues to be affected,
• Less scarring compared to other
modes of energy
Disadvantages
• Very expensive equipment.
• Risk of OR fire.
• Increased operating time in
general.
• Air embolism which can be fatal.
• Either the precision or efficiency
of the laser has to be
compromised – one of them is
usually sacrificed

51. Argon Beam Coagulation

52. • In ABC, a directed beam of Argon gas from the electrode tip aids in conduction of
the radio frequency current to the tissue by ionization.
• Like laser, this is a non-contact method where the argon gas - which is a good
conductor of electricity - acts as a means of transportation of the current from
the tool to the tissue.
• ABC performs faster than conventional coagulation systems and provides a more
uniform and shallower coagulation region which results in faster dispersion thus
minimizing tissue damage
• The ABC system is usually connected together with an electrosurgical system
where argon gas is released from the tip of the tool to achieve hemostasis.

54. Advantage
• Most effective form of hemostasis
and is used in procedures involving
major blood loss.
• Translates to faster coagulation
times.
• Argon gas blows away blood and
debris from the surgical field and
produces a coagulated surface that is
more uniform.
• less smoke than conventional.
• It has shown that the thermal spread
is constant (2–3 mm)
Disadvantage
• The major drawback of ABC is argon
gas embolism which is a result of the
insolubility of argon gas in blood.
This has resulted in cardiac arrests
and even death.
• Mostly used for coagulation (not
used for cutting).
• Involves the use of electricity, hence
the risk of interference with surgical
equipment exists.

57. Conclusion

58. • When considering thermal damage
Max – monopolar electro-surgery
Min - ultrasonic energy
• In terms of their performance
highest seal strength in smaller vessels - ultrasonic devices
highest seal strength in larger vessels – electro-surgery
• most effective hemostasis on irregular surfaces
Argon beam coagulation (however, it also leads to gas embolism.)
• In electrosurgery, RF is the most common form of electromagnetic radiation used
followed by microwave radiation.

59. • Lasers are very expensive and are mostly limited to gynecological treatments in
laparoscopy today, though at one time, they were widely used in many
laparoscopic procedures such as cholecystectomy.
• In blood vessel sealing, the effectiveness of an energy device is dependent on the
size of the blood vessel. The harmonic scalpel is shown to have reduced overall
time compared to other energy sources in MIS.
• In terms of death from complications, lasers and ABC have more reported cases
than the other methods.
• Electro-surgery is still very popular in MIS due to its familiarity with surgeons and
the development of various enhanced safety features to minimize injuries.

60. Bibliography
• Society of American Gastrointestinal and Endoscopic Surgeons (SAGES)
(YouTube/SAGES/Fundamental Use of Surgical Energy)
• Principle of electro surgery (pdf by CONVIDIEN)
• Schwartz's Principles of Surgery, 10th Ed (pg-426 /Energy Sources for Endoscopic
and Endoluminal Surgery)
• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3755039/
• http://blog.boviemed.com/blog-1/bipolar-electrosurgery-vs.-monopolar-
electrosurgery
• http://www.fda.gov/Drugs/DrugSafety/SafeUseInitiative/PreventingSurgicalFires
/default.htm

61. Presentation By :
Under Guidance Of :
Dr. Jayesh V. Parikh
(Head Of Unit – Surgery, Saturday Unit)
Civil hospital, Ahmedabad
Dr. Hiral Chauhan
Assistant Professor
Dr. JVP Unit (Surgery)
Civil Hospital
Mayur Patel
Intern : Dr. JVP Unit (Surgery)

62. Thank You
http://www.slideshare.net/MayurPatel64/enery-sources-in-surgery-57931879