Energy sources jb
•
44 likes•8,737 views
This document provides information on various techniques and technologies used in electrosurgery. It discusses the history and evolution of electrosurgery from the 1920s to present. Key aspects covered include the differences between electrocautery, electrosurgery, monopolar vs bipolar methods, and tissue effects. Complications are reviewed. Newer energy sources and technologies are introduced, such as advanced bipolar devices from Gyrus ACMI, Ethicon Endo-Surgery, and Covidien.
Recommended
More Related Content
What's hot
What's hot (20)
Similar to Energy sources jb
Similar to Energy sources jb (20)
More from Tariq Mohammed
More from Tariq Mohammed (20)
Recently uploaded
Recently uploaded (20)
Energy sources jb
- 1. Dr. James Bentley Professor Department of Obstetrics and Gynecology Dalhousie University Halifax NS Thanks: Dr N VanEyk Assistant Professor Dalhousie University
- 2. Speaker Disclosure: — No conflicts to disclose
- 3. Radiofrequencies 60 Hz 100 kHz 550-1550 kHz 54-880 MHz 500 kHz – 33 MHz Electrosurgery Muscle & nerve stimulation cease
- 4. Electrocautery — Direct Current (electrons flowing in 1 direction) — Heats an alloy (metal) which is then applied to tissue: does not flow through patient
- 5. Electrosurgery History In 1926 Harvey Cushing, consulted with a physicist connected with the Harvard Cancer Commission, William T. Bovie. Together they worked to create the most effective circuits and electrodes, which were introduced into surgery in October of 1926.
- 6. Electrosurgery Evolu;on 1920s Present 60hz Grounded Circuit >200 000hz Isolated Circuit Alternate Site Burns No Alternate Site Burns Return Electrode Burns Return Electrode Burns Still Possible
- 7. Electrosurgery — High frequency — Alternating Current — Current enters patient s body as part of the circuit
- 8. Ohm s Law: I=V/R — Current = I: flow of electrons/time (amps) — Resistance (impedance) = R :obstacle to the flow of current (ohms) — Voltage = V: force pushing current through the resistance (volts) — Power = V x I (watts)
- 9. Monopolar vs. Bipolar • Cut/coag • ↑ dissection • ↑ current density: ↓ thermal spread • ↓ “stick” • ↓impedance à ↓voltage à ↓ heat • no grounding pad • ↓ coupling • ↓ smoke • ↑hemostasis • wet OK • implants OK Safer
- 10. CuIng vs. Coagula;on Safer
- 11. Tissue Effects — Cutting= Vaporisation — Fulgaration — Coagulation=Dessication — The difference between cutting and coag is the rate at which the tissue heats up. — This is manipulated by varying the current density (surface area)
- 13. Complica;ons: Capacitance Coupling
- 14. Complica;ons: Capacitance Coupling
- 16. Energy Sources: The New Genera;on — Higher Current, Less voltage — Less thermal spread — Plug & Play : output & power preset — Impedance feedback & adjustments — Grasp, dissect, coagulate & transect with one instrument — Disposable: safer, more efficient but ↑$
- 17. Energy Sources: Op;ons — Advanced Bipolar Devices — Gyrus ACMI (Olympus) — Enseal (Ethicon Endo-‐Surgery) — Ligasure (Covidien) — Ultrasonic Shears — Harmonic Scalpel (Ethicon Endo-‐Surgery) Vessel Sealing Devices
- 18. Gyrus ACMI — PK (plasma kinetic) energy delivered in a series of pulses (VPC = vapor pulse coagulation) à boil fluid in tissue à steam creates vapor pockets which coalesce to form vapor zones — High resistance within zone, low at periphery à highest current density at edges where tissue moist/not coagulated
- 19. Gyrus ACMI — Pulse/cool off period cools instrument à reduces drying and electrode sticking — Pulses repeated until tissues don t absorb fluid = uniformly coagulated à audible and visual impedance end point indicators — Vessel sealing capacity
- 20. Gyrus: PKS laparoscopy instruments — Cutting Forceps — L-‐Hook — Plasma J-‐Hook — PlasmaSORD™ Bipolar Morcellator — PlasmaSpatula®: coag with one surface, rotate 90 degrees and cut
- 21. Enseal — Adjusts energy simultaneously to various tissue types in a tissue bundle (each with own impedance characteristics) — Proprietary electrode with millions of nanometer sized conductive particles embedded in a temperature sensitive material ( Smart electrode technology ); each particle-‐discrete thermostatic switch — To keep temperature from rising dangerously – each particle interrupts current flow to a specific tissue region. When temperature dips below optimal fusion level, particle turns back on; temp maintained ~ 1000 C
- 22. Enseal — Process continues until entire tissue segment is uniformly fused without charring or sticking — Less heat required-‐tissue volume reduced by compression; limits lateral thermal spread — Vessel walls fused by compression, protein denaturation, then renaturation — up to 7mm vessel diameter — withstand up to 7 x systolic pressure
- 23. Enseal — Enseal Trio Tissue Sealing Device
- 24. Ligasure — Electrosurgical Collagen Welding : Combination of pressure and energy; denature collagen and elastin to reform a permanent seal; hydrothermal rupture of hydrogen cross links by elevating to 60-‐95 ºC — Cooling allows renaturation of entangled unwound collagen strands; high uniform mechanical compression increases entanglement/recrosslinking upon thermal relaxation — Permanently fuses vessels and tissue bundles without dissection or isolation
- 26. Ligasure — Average seal cycle is 2 to 4 seconds* — up to 7 mm vessel diameter — withstand up to 3 x systolic blood pressure — Impedance feedback – adjusts energy output based on real time measurements of tissue impedance 3333 times/second — Feedback-‐controlled response system automatically discontinues energy delivery when the seal cycle is complete
- 27. Ligasure: Laparoscopic Instruments — LigaSure Advance™ Pistol Grip1 — LigaSure™ 5 mm: blunt2 — LigaSure Advance™ — LigaSure™ V: dolphin3 — LigaSure Atlas™ — LigaSure™ Lap: Maryland *Advance: monopolar tip 1 2 3
- 28. Ultrasonic Shears Piezoelectric ceramic discs convert electrical energy into mechanical vibrations • Lysis hydrogen bonds • Denature proteins • Steam formation • Cavitational fragmentation à tissue falls apart = cutting
- 29. Harmonic Scalpel — Amount of blade excursion modifies tissue effect; cutting speed increases with higher settings (1 -‐ 5) — No electrical energy à no risks coupling — No smoke (steam only) — Minimal lateral thermal spread — Small – medium vessels: up to 5mm
- 30. Harmonic Scalpel — ACE curved Shears — Coagulating Shears — Dissecting Hook
- 31. Harmonic Scalpel
- 32. How do we decide??
- 33. Comparison: Mean Burst Pressure Newcomb et al. Comparison of blood vessel sealing among new electrosurgical and ultrasonic devices. Surg Endosc 2009; 23 (1):90–96
- 34. Comparison: Mean Seal Time Surg Endosc 2009; 23 (1):90–96
- 35. Comparison: Failure Rates Surg Endosc 2009; 23 (1):90–96
- 36. Comparison: Temperature Range F. J. Kim et al. Temperature safety profile of laparoscopic devices: Harmonic ACE (ACE), Ligasure V (LV), and plasma trisector (PT). Kim et al. Surg Endosc 2008; 22:1464–1469
- 37. Comparison: Cool Time Surg Endosc 2008; 22:1464–1469
- 38. Histologic effects A:Harmonic Scalpel B: Gyrus PKS cutting forceps C: Ligasure V with forced triad Generator D: Ligasure V with vessel sealing generator E: Gyrus Plasma Trissector
- 39. What do you want/not want? — Tissue Handling — Grasper, Elevator — Dissector — Vessel Sealing — Hemostasis — Handpiece expandability — Tissue Products — Plume, Smoke, Steam — Heat — Carbon, Stick — Response to fat — Response to tension
- 40. What do you want/not want? — Handpiece — Activation: hand vs. foot pedal — Blade activation: on closing vs. separate trigger vs. none — Rotational tip/shaft — Jaw design: shape, length, width — Size: 5mm, 10mm — Cost
- 41. Summary — Electrosurgical Principles: — Use lowest voltage possible for the shortest time possible — Bipolar safer than monopolar — If monopolar, cut safer than coag — Advanced Electrosurgical Instruments — Understand their mechanisms of action — Assess what you need them to do — Trial them: look, hold, use — Cost feasibility