Energy source used in laparoscopic surgery(1) (1).pptx

Energy source used in laparoscopic surgery

1. Energy Sources used in Endo-Laparoscopy Prof. Dr. Rafiques Salehin Professor & Head Department of Surgery Sir Salimullah Medical College Mitford Hospital

2. Most convenient Way of Dissection / L aparoscopic dissection Electro-surgery Blunt dissection Pledget Gauze Instrument Sharp – knife , Scissor. Newer device – Laser / Ultrasound / hybrid. Electro-surgery – use of A/C current. Most convenient but risky.

3. Energy sources in laparoscopic surgery -- 3 categories . Electrosurgery – When alternate current is passed between the tissue & the heat is produced used to create the desired effect of cutting & coagulation. Exact effect depends on the temperature achieved. A t temp. 70 – 100 c coagulation occur. Above 100 c desiccation occur. Effect on tissue can be further modified by alternating the waveform of ac current. For cutting effect low voltage current creates faster heat generation & vaporization For coagulation burst of high voltage current used. Tissue does not vaporizes but cools between burst. Blend contains a mix of cutting & coagulation 1.Monopolar Electrosurgery 2. Bipolar Electrosurgery 3 . Advance Bipolar . Ultrasonic Source Laser Energy source

4. Electrosurgery Vriables impacting tissue effect Waveform – Fulguration (Small fulguration, Spray), Desiccation, Blend, Pure cut. Power setting – Not more than 40 watt. As minimum Site of electrode Time - 3 sec burst. Manipulation of electrode Type of tissue Eschar Burn – Intensity of current . Time. Area. Remote burn. Charcoal. Like cigarette. Tripolar electrosurgery – Disection , Grasping, Bipolar coagulation, Bipolar cut.

5. Physics of Electricity Circuit = Pathway or flow of electrons Current = Amount of electrons flowing (amps) (I) Voltage = Driving force (volts) (V) Resistance = Impedance or obstacle to flow of electrons (ohms) (R) Ohm’s Law: (V = I x R) Power = Energy/ heat produced or used over a period of time (watts) (P = V x I)

6. Ohams law – V = IR : I = V/R : R = V/I. V = Voltage , I = Current flow, directly proportionate to resistance. R = Resistance Amount of steady current is directly proportionate to potential difference or voltage. Current through a conductor is proportional to the voltage across the conductor. Temperature remains constant

7. There are T wo types of current: Alternating and Direct. With Direct Current , electrons flow in one direction. Example: a flashlight. Current flows from the battery to the lamp and creates light. With Alternating Current , electrons flow bi-directionally. The direction of flow is constantly being reversed. Both Monopolar and Bipolar Electrosurgery utilize Alternating Current.

8. Two Types of Electrical Circuit DC - Direct Current Unidirectional flow of electricity eg - Battery AC - Alternating Current Direction reverses cyclically eg - Household electricity Monopoloar Electrosurgery Bipolar

9. Cautery - Electrocautery - Electrosurgery Cautery The surgical use of heat Electro-cautery The process of destroying tissue with an object that is heated with electricity There is no current flowing through the patient. Electro-surgery The use of alternating current passing through the patient to cut and coagulate tissue

10. Advances in electrosurgical equipment – High frequency Diathermy. Argon plasma coagulation. Bipolar vessel sealing device Radiofrequency surgery Combination of ultrasound & Bipolar system. The addition of cutting blade Tissue impedance sensor Electrode configuration with reduced lateral thermal spread.

11. Electrosurgical injury during laparoscopic surgery – Main causes Inadverent grasping or touching of tissue during application. Insulation break in the electrode. Direct sparking to the intestine from the diathermy. Direct coupling /DC Coupling/ Conductive Coupling between a portion of intestine & a metal probe that is touching the activated probe. Inductive coupling / Magnetically coupled – Changes through one wire induces a voltage across the end of other wire through electromagnetic induction Capacitive coupling – Transfer of energy within a network or between distant network by means of displacement current between circuits. Nodes, induced by the electric field. Disperse electrode burn Alternate site burn Ground point burn

12. Tissue effects of heating Temperature (Centigrade) 34-44 44-50 50-80 Effect Visible None None Blanching Delayed Edema Necrosis Sloughing Mechanism Vasodilatation Inflammation Disruption of cell metabolism Collagen denaturation

13. Tissue effects of heating Temperature (Centigrade) 80-100 100-200 >200 Effect Visible Shrinkage Steam “popcorn” Carbonization cratering Delayed Sloughing Ulceration Larger crater- Mechanism Desiccation Vaporization Combustion of tissue hydrocarbons

14. Monopolar Electrosurgery

15. Monopolar Electrosurgery Waveform refers to the shape of the electrical signal as it travels along the circuit. Different waveforms indicate the generator is delivering current at different voltages . Low voltage is safer simply because it delivers less force. Any modality can be used to desiccate (dry up) tissue. The difference is how the current is applied to the tissue. In Electrosurgery , there are 3 basic waveforms: •  Cut (vaporization) • Coagulation – Fulguration , Coagulation. • Blend (cutting and coagulation)

16. Monopolar Electrosurgery Cutting is achieved by an electrosurgical instrument that is in close proximity to tissue. The instrument doesn’t actually mechanically cut the tissue. Coagulation: Two types of coagulation current: • Fulguration : T ip is not touching the tissue (Also called Non-contact Coagulation. Also called Spray). Spreading with coagulation waveform. Coagulates and chars the tissue over a wide area, results In coagulum. • Desiccation : the tip is touching the tissue. (Also called Contact Coagulation) The three main actions of Electrosurgery are - Cutting, Fulguration, and Desiccation. Cutting Fulguration Desiccation

17. Traditional Bipolar Monopolar Circuit Current flows from a small (active) electrode to and through the patient to a large, indifferent (ground) electrode The patient is vital to completing the circuit How it works

18. Monopolar Electrosurgery In Electrosurgery , a complete circuit is necessary for current to flow. In Monopolar Electrosurgery , • The current flows from the pencil through the patient to the pad and back to the generator. • The patient’s tissue completes the circuit. What’s the difference between the pencil and the pad ? The pencil is small and delivers higher current concentrations. The pad is larger and dissipates the current over a larger area. The tissue effect occurs at the pencil, where current concentrations are high.

19. Advantages of Electro cutting • Reduced bleeding • Prevention of germ implantation • Avoidance of mechanical damage to the tissue • Endoscopic applicability

20. Risk of Monopolar Electrosurgery • Active Electrode Trauma • Current diversion – Alternate ground site burns – Direct coupling – Indirect coupling – Capacitive coupling • Dispersive electrode burns • Smoke inhalation Insulation failure

21. Impact of unintended current flow . As you’re treating the tissue, the tissue impedance changes As the tissue impedance (resistance) increases on the gallbladder side then the current starts to flow towards the duodenum Effect may be compounded by current density on duodenal side gallblader deodenum Increased current density

22. Potential Risks of Monopolar Electrosurgery

23. Indifferent Electrode (Return Pad) Failure If the pad lost partial contact, current could concentrate at that site and produce injury. This resulted in the classic “grounding pad injury or burn” often experienced with older electrosurgical systems. Tissue Correct Active Electrode (pencil ) Incorrect Active Electrode (pencil ) Indifferent Electrode

24. Safe Use of Monopolar Electrosurgery Best Practices Consider using cut waveform Use lowest power setting for desired tissue effect. Check insulation on all instruments and connectors before use. Use isolated generator and patient contact quality monitoring system (standard practice in the U.S.) Techniques to Avoid Avoid an open circuit Limit activation with electrode off tissue (limit direct coupling) Clean eschar off of the instrument tip Avoid inadvertent contact of metal-to-metal

25. Bipolar Electro surgery

26. Bipolar energy • First described in Gyne surgery in 1973 by Rioux . • Described as an evolution in comparison to monopolar energy: safer & less thermal spread Rioux JE, Cloutier D. A new bipolar instrument for laparoscopic tubal sterilization. Am J Obstet Gynecol. 1974;119:737–741.

27. How it works Traditional Bipolar Circuit Voltage is applied to the patient using forceps A high frequency electrical current flows from one of the tines to the other tine, through the intervening tissue The tissue within the forceps completes the circuit An indifferent electrode is not required

28. Technology: Traditional Bipolar Electrosurgery High current concentrations Relatively low voltage Current generates heat in tissue Reduced risk of capacitive and direct coupling Surgeon visually controls the delivery of energy

29. Principles: – Closed system with active electrode and passive electrode – Interrupted frequency of about 500 KHz – Low voltage interrupted current – Specific instrumentation: graspers or forceps Bipolar energy Introduction

30. Bipolar energy Introduction Disadvantages Minimal cutting effect Capacity of thermal damage Spread Advanced Bipolar Circuit High frequency, low voltage, current flows from one jaw to the other Tissue within the jaws completes the circuit Return pad is not required NO alternate site burns Less direct and capacitive coupling

31. Bipolar energy ROBI bipolar Advantages • Excellent dissection tool • Grasping forceps • Cheap • Re-usable Disadvantages • Important lateral spread of heat • Possible to touch by accident other tissues (not covered tip) • Does not measure tissue impedance or temperature

32. Bipolar energy Enseal Advantages • Fast & efficient (up to 7mm) coagulation & cut • Measure tissue impedance & temperature • Minimal thermal spread Disadvantages • Capacity of thermal damage spread • Dissection limited • Similar to Ligassure

33. EnSeal  This system provides vessel sealing by combining a compression mechanism with thermal energy control in a bipolar sealing device. The instrument is capable of achieving seal strengths up to seven times the normal systolic pressures on vessels up to 7 mm with a typical thermal spread of approximately 1 mm. Although there have been few publications about this device in the medical literature , it is already in widespread use among surgeons.

34. The compression mechanism applies uniform pressure along the full length of the instrument jaw, similar to those of a linear stapler. Compression is combined with controlled energy delivery utilizing NanoPolar ™ thermostats to reach collagen denaturation temperatures in seconds, which are maintained at approximately 100ºC throughout the power delivery cycle. The device also has a cutting mechanism to allow one-step sealing and transection of vessels and soft tissues. EnSeal

35. Bipolar energy Ligasure

36. LigaSure P recise amount of bipolar energy and pressure to fuse collagen and elastin within the vessel walls. This results in a permanent seal that can withstand T hree times the normal systolic pressure S eals vessels up to 7 mm . The sealing is achieved with minimal sticking and charring. T hermal spread approximately 2 mm to adjacent tissue. The generator for this device uses a feedback-controlled response system to ensure adequate tissue sealing

37. LigaSure U sed successfully in a variety of procedures, such as TLH and laparoscopic oncology surgery U sed effectively in laparoscopic C olectomy, H epatectomy , S plenectomy . The main disadvantage in using this system over standard bipolar technology is Cost , especially since these devices are disposable . Non disposable devices that use similar technology have been introduced with promising initial results

38. Advantages Fast and efficient (up to 7mm) coagulation and cut Measure tissue impedance Minimal thermal spread (2mm) Cut function Disadvantages Capacity of thermal damage spread Dissection limited Bipolar energy Ligasure

39. Bipolar energy Thunderbeat Advantages • Combines ultrasonic energy to bipolar • Better cutting • Strong pressure distributed to tissue • Minimal thermal damage Disadvantages • To control tip of the instrument after activation • To know how to use two different types of energy

40. Bipolar energy PKS Plasma SORD PK Bipolar morcellator Advantages • Reduced time • Continuous bipolar morcellation : no blunt blades • Less fatigue for operating surgeon Disadvantages • Possible thermal lesion to patient

41. The HARMONIC System Electrical energy from the generator is converted to mechanical motion in the hand piece.

42. Harmonic Scalple A Harmonic scalpel C uts and Coagulates tissue via vibration. The scalpel surface itself cuts through tissue by vibrating in the range of 55,500 Hz. The high frequency vibration of tissue molecules generates stress and friction in tissue, which generates heat and causes protein denaturation. This technique causes minimal energy transfer to surrounding tissue, potentially limiting collateral damage.  However, incidents have been reported where the active jaw has caused bowel perforation

43. Harmonic Scalpel Ultrasonic cutting and coagulating device   The ultrasonic cutting and coagulating surgical device converts ultrasonic energy into mechanical energy at the functional end of the instrument. A piezoelectric crystal in the hand piece generates vibration at the tip of the active blade at 55,500 times per second over a variable excursion of 50 to 100 micrometers . This results in rupture of hydrogen bonds and produces heat , which leads to denaturation of proteins and, eventually, separation of tissue. These effects are reached at tissue temperatures of 60 to 80ºC , resulting in coagulum formation without the desiccation and charring caused by temperatures of 80ºC and higher associated with traditional electrosurgical methods 

44. The harmonic scalple used successfully in a number of open and laparoscopic procedures The advantages of this technology include M inimal thermal spread, D ecreased tissue charring and D ecreased smoke formation compared traditional electrosurgical instruments. No risk of electrical injury. It is also a versatile instrument, allowing the surgeon to dissect, cut, and coagulate using one instrument. Harmonic scalpel