Various energy modalities are used in urology for tissue dissection, cauterization, or intra / extra corporeal lithotriptors

1. Energy Sources in Urology
-Dr. Shubham Lavania
30/06/2017
“HEAT CURES WHEN EVERYTHING ELSE FAILS”- Hippocrates
Tissue Dissection and Cauterization
Intracorporeal Lithotripters
ESWL

2. • Electrosurgery ??
Classification -Type of Generator Used:
A. Simple generator: mono/ Bipolar cautery
B. Advanced Bipolar System:
I. Ligasure
II. PK system
III. Enseal
C. Ultrasonic
D. Integrated US & ABS
E. Argon Beam coagulator
F. Lasers
G. Others: radiofrequency, microwave, Cryo

3. Mono polar:
•Circuit
•100 W of power to the tissue
at voltages ranging from 100
to 5000 volts
•Cut, Coagulate, blend
•Fulgration , dessiccation
Bipolar:
Circuit
Safety:
1. Patient pad placement
2. Demodulated current (250-2000KHz)
3. Direct application
4. Direct coupling
5. Insulation failure
6. Capacitative coupling

4. Ligasure:-
• Combines pressure and energy
• Uses higer current & low voltage
• Vs upto 7mm
Gyrus PK tissue management sysytem:-
• Vapour pulse coagulation
Enseal:-
• Patented blade & smart electrode technology

5. Physics of US:
2types: Low power: CUSA
High power(55.5 kHz): Harmonic
– Working
– Advantage
Integrated US and ABG: Thunderbeat
Argon beam Coagulation: uses radiofrequency
electrical energy.
• Properties of Argon
• Non contact, monopolar electrothermal
hemostases.
• Use/ drawback

6. Radiofrequency ablation: probe+ radiofrequency
generator= >100⁰C
Use in tumor ablation
Microwave ablation: ultra high speed
(2450MHz) alternating field current.
Cryotherapy: rapid cooling of cell and thawing.
Limited uses

7. Lasers
• “light amplification by stimulated emission of
electromagnetic radiation.”
• Each wave exists as a bundle of energy
• Properties :
– Monochromatic
– Coherent
– Directionality
• Pulsed or continous
• The power of the laser is equal to the energy over
time
• Light-Tissue Interaction-

8. Types of Lasers
Neodymium:Yttrium-Aluminum-Garnet:
– wavelength of 1064 nm
– Penetration- 1 cm
Potassium Titanyl Phosphate
– wavelength to 532 nm
Holmium:YAG
– 2140-nm pulsed laser
– Ts pene-0.5mm
Thulium:YAG
– 2000 nm
– Diode laser

9. Intracorporeal Lithotripters

11. Extracorporeal Shock wave Lithotripsy
Physical Principles
• Shock wave focusing-sufficient strength only
at the target (F2)
• Generator type:
1. Electro hydrolic
2. Electro megnetic
3. peizoelectric

13. Imaging Systems
1. Fluoroscopy
2. Ultrasound
3. Combined
Anesthesia
• discomfort experienced~energy density &
size of F2
• Narcotic, sedative-hypnotics
• EMLA cream

14. •shock wave profile
•Mechanics of stone fragmentation
1. Spall fracture
2. Squeezing-splitting or
circumferential compression
3. Shear stress
4. Superfocusing
5. Cavitation
6. Dynamic fracture process

15. Bioeffects: Clinical Studies
• Acute extra renal damage: Liver, spleen pancreas,
cardiac, muscles.
• Acute Renal Injury: hematuria, subcapsular
hematoma
• Chronic Renal Injury: systemic blood pressure,
↓renal function, ↑ rate of stone recurrence, and
the induction of brushite stone disease
Risk Factors for Shock Wave Lithotripsy
• Age Obesity
• Coagulopathies Thrombocytopenia
• Diabetes mellitus Coronary heart disease
• Preexisting hypertension

16. Aggravating Factors
• Number of shocks
• Period of shock wave administration: Shorter period
increases damage
• Accelerating voltage: Higher voltage increases damage
• Type of shock wave generator: First- versus
second/third-generation devices
• Kidney size: Juvenile versus adult
• Preexisting renal impairment
Mitigating Factors
• Pretreatment with 100 to 500 shocks at low energy
level to reduce lesion size
• Treatment at a slow rate of shock wave delivery (≤60
shocks/min)

17. AUA Recommendations
• Clinicians should inform patients that SWL is the
procedure with the least morbidity and lowest
complication rate. S R; Grade B
• Routine stenting should not be performed in patients
undergoing SWL. S R;Grade B
• In symptomatic patients with a total non-lower pole
renal stone burden ≤ 20 mm, clinicians may offer SWL
or URS. SR grade B
• Clinicians should offer SWL or URS to patients with
symptomatic ≤ 10 mm lower pole renal stones
• In pediatric patients with a total renal stone burden
≤20mm, clinicians may offer SWL or URS as first-line
therapy. MR; Grade C