Energy Sources used in Surgery

1. Dr.S.Harsha Vardhan

2.  Electrosurgery - use of radiofrequency alternating
current to vaporize or coagulate tissue.
 Cautery (Kauterion = hot iron) - destruction or
denaturation of tissue is by passive transfer of
heat or application of caustic substance

3.  Technology growth
 Effective use in Laproscopic Surgery > Open
Surgery
 Thorough understanding & Proper knowledge of
usage for ‘Safe Surgery’
 Weapons in unskilled hands

4.  4 forms –
1. Electrical
2. Ultrasonic
3. Argon Beam
4. Laser

5.  Oldest & widest usage
 Mentioned in ancient medicine – 3000 BC
 Fire Drill
 Rapid turning of instrument to produce heat
 Used as cautery to control bleeding

6.  Hippocrates used it for Hemorrhoids treatment
 Initially using ‘Single’ electrode
 Later usage of ‘Two’ electrodes

7.  Flows in – Path of ‘Low’ resistance
 Always seeks to return to ground (-ve pole)
 Current (I) - measure of the electron moment past
a given point in the circuit in a fixed period of
times ~amperes
 Voltage (V) - pressure with which the electrons
are pushed through the tissue ~volts

8.  Resistance (R) - measure of the difficulty that a
given tissue presents to the passage of
electrons~ohms
 Power (W) - capacity to do work per unit
time~watts
 Ohm’s Law , i=V/R

9.  DC
 AC – Alternate flow of electrons– Hertz/Cycles
per second
- Normal is 60Hz
- ElectroSurgical Unit – 60Hz to 500
KiloHz

10.  Converts a 60 cycles / sec (60 Hz), lowvoltage
alternating current into higher voltage radio
frequency (500 KHz - 3.0MHz) current.

11.  Current flow – Least Resistant Path
 Tissue with More Water Content
 Blood Nerve Muscle Adipose Bone
 Dessicated tissue ‘Non-Conductive’
 Surrounding tissue damage

12.  Electrocautery – Instrument to heat tissue
 Electrosurgery – Current flows through tissue to
produce changes

13.  Circuit to be completed
 From Active elctrode
 Ends in Passive electrode

14.  MonoPolar Cautery

17.  Advantages –
- Easy to use
- For tissue dissection
- Greater tissue penetration
- Area of Coaguation > BiPolar
 Disadvantages –
- Larger volume of tissue injured
- Can interfere with pacemakers
- Requires distant return electrode

18.  Tissue effects of R.F.Electrical Current –
- Vaporization or cutting
- Desiccation or coagulation
- Fulguration - High voltage modulated current
with a short duty cycle
 Vaporization and fulguration - Non contact
procedures

23.  BiPolar Cautery

24.  2 arms in hand piece
 Damage to tissue b/n 2 electrodes
 Tissue damage inc. Tissue resistance
 Dec./no damage to surrounding tissue

26.  Advantages
- Dec. Thermal injury to surrounding
tissue
- Works well in saline
- In Pt with Pacemaker
- Dec. Risk of capacitive coupling injuries

27.  Disadvantages
- More skill
- Coagulation only
- No dissection capabilities

28.  50-80℃ = Tissue coagulation
 Around 100℃ = Dessication & Vapourisation
 200-300℃ = Tissue Carbonisation

29.  Amount of heat generation depends on
- amount of tissue in contact with
electrode (similar to pressure principle)
 Short duration , High Voltage – Coagulation due to
rapid tissue heating
 Low Voltage , High wattage current – Tissue
cutting

30.  Reduced bleeding
 Preclution of germ implantation
 Avoidance of mechanical damage to thetissue
 Endoscopic applicability

31.  Endogenous burns
 Exogenous burns
 Pseudo burns
 Active Electrode Trauma
 Current diversion
 Alternate ground site burns
 Direct coupling
 Indirect coupling
 Capacitive coupling
 Dispersive electrode burns
 Smoke inhalation

35.  Uses 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

37.  Uses high-frequency mechanical vibrationsto fragment
tissue
 Used in ophthalmic, neuro, hepato-biliaryand oncologic
cytoreductive surgery
 Fragments tissue by contact with high water content
cells
 Vibration generate vapor pockets within the cells that
lead to disruption and fragmentation

39.  Produces vibrations at 55.5KHz at the tip ofthe
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

40.  Can perform cutting and heamostasis with minimal
damage
 Limited lateral spread and thermal injury
 No electrical energy transferred to patients

41.  Uses a spray of ionized argon gas as the active
electrode rather than a metallic blade
 Allows even, efficient and broad application of the
coagulating current to the tissues
 Ideal for obtaining haemostasis along the cut
surface of the liver following hepatic resection

43.  Light Amplification by Stimulated Emission of
Radiation
 Differs from regular light in the following properties
–
- Coherence (waves are synchronised
or in phase with each other)
- Monochromaticity (single
wavelength)
- Collimation (all light waves in
parallel , so single beam)

45.  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

46.  Ligasure – BiPolar Vessel Seal Device
- Combination of pressure & energy
source to enable vessel seal

47. Rachet grips vessel tightly
Measures resistance in adipose tissue & sent to
generator
Delivers energy in pulsed manner
Continues till vessel sealed
 Vessels upto 7mm with 3times normal systolic pressure

48.  Gyrus PK Generator –
- Pulsed radiofrequency energy
Grasp , dissect , coagulate , vapourise , resect ,
hemostasis
Intermittent delivery of energy
No charring or sticking of tissue

50.  Enseal RF System –
- adjust dose energy simultaneously
accounding to the impedence of
tissue
- millions of nano sized conductive
particles in temperature sensitive
material
- sealing arteries , veins , transecting
adipose tissue , ligaments &
connective tissue

52.  Hydrojet Device –
- Jet of water for dessection of tissue
- Liver parenchyma , Renal hilar
dissection
- No thermal injury

53.  Floating Ball : Cutting & Hemostatic Energy
- Monopolar current combination
with water cooled and RF energy
- Blunt dissection , Coagulation

54. - Radiofrequency current close to tip
sealing small vessels
- Current passes through saline and
converted to electrical energy at
tip of instrument
- No scar formation , as cooled by
saline
- upto 3mm vessels coagulated