16- Surgical Techniques & Technology Explains Flashcards
What is electrosurgery?
Electrosurgery is a technique that uses the heat generated by high-frequency alternating electrical current to treat living tissues.
How does electrosurgery generate heat in tissues?
The application of a voltage across human tissue creates an electrical circuit, and the tissue acts as a resistor. The resistance of the tissue, determined by its water content, leads to the formation of heat.
What is the frequency range at which most diathermy units operate?
Most diathermy units operate at a frequency between 200,000 kHz to 5 MHz.
What are the three main therapeutic modalities that can be achieved with electrosurgery?
Electrosurgery can deliver three main therapeutic modalities: cutting, coagulation, and blend.
What is the purpose of the cutting modality in electrosurgery?
The cutting modality in electrosurgery utilizes a sinusoidal and non-modulated waveform with high average power and current density. It allows for precise cutting without causing thermal damage to the tissue.
How does the coagulation modality work in electrosurgery?
The coagulation modality in electrosurgery uses a modulated current with intermittent dampened sine waves of high peak voltage. It results in the evaporation, rather than vaporization, of intracellular fluid and the formation of a coagulum.
What is the purpose of the desiccation modality in electrosurgery?
The desiccation modality in electrosurgery involves the active electrode being in direct contact with the tissue. It uses a low current and high voltage system, resulting in the loss of cellular water without causing protein damage.
What does the fulguration modality in electrosurgery involve?
The fulguration modality in electrosurgery uses an electrode probe held away from the tissue. It produces a spray effect with local, superficial tissue destruction. It operates using a low amplitude and high voltage system.
What is the purpose of the blend mode in electrosurgery?
The blend mode in electrosurgery combines alternating cutting and coagulation modes. It has a total average power that is less than with cutting alone.
What is the suture material called that is braided and biological?
Silk
What are the common uses for silk sutures?
Anchoring devices and skin closure.
What is the durability of silk as a suture material?
Theoretically permanent, although its strength is not preserved.
What is the suture material called that is braided and biological, degrades rapidly, and is not available in the UK?
Catgut
What are the special points to note about silk sutures?
Silk sutures knot easily and result in poor cosmesis.
How long is catgut suture typically used for?
5-7 days for short-term wound approximation.
What are the drawbacks of catgut sutures?
Poor cosmesis and unpredictable degradation pattern.
What is the suture material called that is braided, biological, and can be used for deep tissue apposition for up to 12 weeks?
Chromic catgut
What are the drawbacks of using chromic catgut sutures?
It has an unpredictable degradation pattern and is not in use in the UK.
What is the synthetic monofilament suture material called that can last up to 3 months (longer with thicker sutures) and has widespread surgical applications?
Polydiaxanone (PDS)
What are some common surgical applications for polydiaxanone sutures?
Visceral anastomoses, dermal closure, and mass closure of the abdominal wall.
What type of suture material is polyglycolic acid (Vicryl, Dexon)?
Braided synthetic
How long can polyglycolic acid sutures be used for?
Up to 6 weeks.
What are the advantages of using polyglycolic acid sutures?
Most tissues can be apposed using polyglycolic acid, and it has good handling properties.
What should be avoided when using polyglycolic acid sutures for skin closure?
The dyed form of this suture should not be used for skin closure.