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Energy sources in surgery

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Different type of Energy Sources used in Surgery are described In this presentation...
like Radio frequency Electro-surgery
Ultrasound Energy
Argon beam Coagulation

Veröffentlicht in: Gesundheit & Medizin
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Energy sources in surgery

  1. 1. Energy Sources 1. Radiofrequency Electro-surgery • Monopolar cautery • Bipolar cautery 2. Ultrasonic Energy System • Harmonic scalpel 3. Laser 4. Argon Beam Coagulation
  2. 2. Radiofrequency electro-surgery
  3. 3. 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
  4. 4. In RF electro-surgery…. • V difference – Produced by Electro- surgical Unit • R (resistance) – By tissue
  5. 5. • More fatty tissue and fibrous tissue provide more Resistance… more duration / more Voltage difference is needed for the same effect.
  6. 6. • Mainly 3 Components Electromagnetic Generator Current : AC Tissue Effect
  7. 7. Input : 50 Hz Output : 500,000 Hz
  8. 8. Cut • Low Voltage + Long Time Pure Cut
  9. 9. Coag • High Voltage + Short Time
  10. 10. In AC current, there is no net flow of electron through Patient… So, less chance of Electrocution.
  11. 11. To & Fro movement of Electron Electrical energy is converted to Kinetic Energy Kinetic energy produces Heat
  12. 12. 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 ?
  13. 13. 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
  14. 14. 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
  15. 15. 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
  16. 16. 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)
  17. 17. Instruments Monopolar Bipolar
  18. 18. • 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.
  19. 19. • Monopolar electro surgery can be used for several modalities including 1. cut, 2. blend, 3. desiccation, and 4. fulguration.
  20. 20. 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.
  21. 21. • 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.
  22. 22. • 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.
  23. 23. 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.
  24. 24. 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.
  25. 25. Mechanical Injuries Dispersive Electrode • Application site issue • Partial detachment Current diversion • Insulation failure • Direct coupling Active electrode injury • Inadvertent activation • Direct extension
  26. 26. OT fire • Triad of Cause leading to OT fire are….. Heat
  27. 27. Ultrasonic Energy System
  28. 28. Ultrasonic Generator Electric Current Tissue Effect Min Max piezoelectric transducers Electric to Ultrasound
  29. 29. • 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
  30. 30. • We can set power level 1 To 5 Power Level Level 5 100% displacement = 100 micron displacement Level 1 50% displacement = 50 micron displacement
  31. 31. • Min Setup > 50 micron Coagulate • Max Setup ~ 100 micron Cut
  32. 32. • Cutting • Coagulation • Cavitations : Motion of blade create Vaporization. Fluid vapor expansion causes layers to separate which enhance Plane of dissection • Drilling
  33. 33. 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
  34. 34. Harmonic Scalpel
  35. 35. 0 2 4 6 Thermal Spread Ultrasonic Bipolar Monopolar
  36. 36. 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
  37. 37. Laser
  38. 38. 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
  39. 39. https://www.youtube.com/watch?v=1LmcUaWuYao
  40. 40. https://www.youtube.com/watch?v=1LmcUaWuYao
  41. 41. • 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)
  42. 42. 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
  43. 43. 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)
  44. 44. 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
  45. 45. Argon Beam Coagulation
  46. 46. • 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.
  47. 47. 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.
  48. 48. Conclusion
  49. 49. • 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.
  50. 50. • 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.
  51. 51. 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
  52. 52. 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)
  53. 53. Thank You http://www.slideshare.net/MayurPatel64/enery-sources-in-surgery-57931879