206: Cryosurgery Flashcards
What is the primary purpose of cryosurgery?
Cryosurgery is used to destroy cells of abnormal or diseased tissue using extreme cold.
What are the effects of rapid freezing in cryosurgery?
Rapid freezing causes intracellular ice crystal formation, disrupting electrolytes and pH changes, leading to cell death more readily achieved.
Which cryogen is considered the cryogen of choice in cryosurgery and why?
Liquid nitrogen is the cryogen of choice because it has the lowest temperature of all common cryogens and causes rapid freeze of treated tissue.
What are the absolute contraindications for cryosurgery?
Absolute contraindications include lesions that require histopathology for diagnosis, recurrent nonmelanoma skin cancers, and tumors with indistinct borders or darkly pigmented features.
What are some risks and complications associated with cryosurgery?
Risks and complications include pain, bleeding, pigmentation changes, nerve damage, scarring, alopecia, and insufflation of soft tissue.
What is the open spray method in cryosurgery?
The open spray method involves using a handheld cryosurgical unit with a fingertip trigger to spray from a distance of 1-2 cm, suitable for superficial lesions with specific clinical freeze margins.
What is the recommended treatment duration for seborrheic keratosis using cryosurgery?
The recommended treatment duration for seborrheic keratosis is 10-15 seconds with a 1-2 mm halo.
What is the goal of treating actinic keratosis with cryosurgery?
The goal of treating actinic keratosis is to destroy the lesion in a single treatment using an open spray, single freeze-thaw cycle of 8-10 seconds with 1-2 mm margins.
A patient presents with a small, well-circumscribed lesion in a confined location. Which cryosurgery technique would you use, and why?
The closed technique should be used because it involves pressing a copper cryoprobe against the lesion, making it ideal for small, well-circumscribed lesions in confined locations.
You are treating a patient with actinic keratosis using cryosurgery. What is the recommended freeze-thaw cycle and margin?
For actinic keratosis, an open spray method with a single freeze-thaw cycle of 8-10 seconds and a 1-2 mm margin is recommended.
A patient with cold urticaria needs cryosurgery. What should you consider before proceeding?
Cold urticaria is a relative contraindication for cryosurgery, so the procedure should be avoided or performed with extreme caution.
What is the primary reason melanocytes are highly sensitive to cryosurgery?
Melanocytes are highly sensitive to cryosurgery because they are more prone to damage from freezing, which can lead to depigmentation.
A patient undergoing cryosurgery experiences paresthesia. What is the likely cause?
Paresthesia is likely caused by nerve damage, which is a potential complication of cryosurgery.
Why is liquid nitrogen the cryogen of choice in cryosurgery?
Liquid nitrogen is the cryogen of choice because it has the lowest temperature among common cryogens, allowing for rapid freezing of treated tissue.
What is the effect of prolonged freezing (>30 seconds) during cryosurgery?
Prolonged freezing for more than 30 seconds can result in permanent pigment loss.
A patient with a dermatofibroma is undergoing cryosurgery. What is the recommended freeze time?
The recommended freeze time for a dermatofibroma is 60 seconds.
What is the primary difference between rapid and slow freezing in cryosurgery?
Rapid freezing causes intracellular ice crystal formation with disruption of electrolytes and pH changes, leading to more effective cell death, while slow freezing causes extracellular ice formation with less cell damage.
What is the role of thawing in cryosurgery, and how does it affect cell damage?
Thawing leads to recrystallization, where ice crystals fuse to form larger crystals that disrupt cell membranes. Longer thawing times result in greater cell damage.
A patient with Kaposi sarcoma is undergoing cryosurgery. What is the recommended treatment protocol?
For Kaposi sarcoma, two freeze-thaw cycles every 3 weeks are recommended, with an average of 3 treatments.
What is the most frequent cryosurgery technique, and how is it performed?
The open spray method is the most frequent technique. It involves using a handheld cryosurgical unit with a fingertip trigger to spray from a distance of 1-2 cm.
What are the absolute contraindications for cryosurgery?
Absolute contraindications include lesions that require histopathology for diagnosis and recurrent nonmelanoma skin cancers.
A patient with seborrheic keratosis is undergoing cryosurgery. What is the recommended freeze time and halo size?
For seborrheic keratosis, a freeze time of 10-15 seconds with a 1-2 mm halo is recommended.
What are the risks of using cryosurgery on lesions with indistinct borders?
Lesions with indistinct borders are a relative contraindication because it may be difficult to ensure complete treatment, increasing the risk of recurrence.
What is the primary use of electrosurgery?
Electrosurgery uses the transmission of electricity to cut tissue, destroy tissue, and cauterize vessels.
What are the main modalities of electrosurgery?
The main modalities include:
- Electrofulguration: No contact with tissue; least damaging; superficial damage to epidermis.
- Electrodessication: Direct contact with tissue; superficial damage.
- Electrocoagulation: Direct contact with tissue; deeper damage; involves the patient in the circuit.
- Electrosection: Bovie knife cuts and coagulates simultaneously.
- Electrocautery: Causes protein denaturation; no current transfer to target tissue.
- Electrolysis: Produces sodium hydroxide and hydrogen gas; used mainly for hair removal.
What are the techniques used in electrosurgery?
The techniques include:
- Monopolar: 1 tip
- Bipolar: 2 tips
- Monoterminal: Treatment electrode without an indifferent electrode
- Biterminal: Use of both treatment and indifferent electrodes
What are the common indications for electrosurgery?
Common indications include:
- Hemostasis: Most common application; coagulation achieved through various modalities.
- Benign tumors: Such as seborrheic keratoses, verrucae, and flat warts.
- Malignant tumors: Curettage and electrodessication (C+D) for BCCs and SCCs.
What is the primary use of electrolysis in electrosurgery?
The primary use of electrolysis is for hair removal, as it liquefies tissue by producing sodium hydroxide and hydrogen gas.
How does electrocautery differ from other electrosurgery modalities?
Electrocautery causes protein denaturation and tissue coagulation without transferring electric current to the target tissue, making it suitable for nonconductive areas like cartilage, bone, and nails.
What is the main advantage of using a Bovie knife in electrosection?
The Bovie knife can cut and coagulate tissue simultaneously, making it efficient for surgical procedures.
A patient with seborrheic keratoses is undergoing electrosurgery. Which modality is most appropriate?
Electrodessication is most appropriate for seborrheic keratoses as it involves direct contact of a monoterminal electrode to the tissue for superficial damage.
What is the primary application of electrosurgery for hemostasis?
Hemostasis is achieved by coagulation using electrofulguration, electrodessication, or electrocoagulation through direct application of the electrode to the bleeding vessel.
What is the difference between monopolar and bipolar techniques in electrosurgery?
The monopolar technique uses one tip, while the bipolar technique uses two tips for more precise energy delivery.
What is the least tissue-damaging modality in electrosurgery, and why?
Electrofulguration is the least tissue-damaging modality because there is no direct contact between the electrode and tissue, causing only superficial damage.
What are the risks of using electrodessication on malignant tumors?
Electrodessication may not ensure complete removal of malignant tumors, increasing the risk of recurrence. It is often combined with curettage for better outcomes.
What is the role of monoterminal electrodes in electrosurgery?
Monoterminal electrodes are used without an indifferent or dispersing electrode, making them suitable for superficial treatments.
What is the primary difference between electrocoagulation and electrodessication?
Electrocoagulation involves deeper tissue damage and uses a biterminal electrode, while electrodessication causes superficial damage with a monoterminal electrode.
A patient with molluscum is undergoing electrosurgery. Which modality is most appropriate?
Electrodessication is most appropriate for molluscum as it involves direct contact of a monoterminal electrode to the tissue for superficial damage.
What is the primary mechanism of tissue destruction in electrosurgery?
Tissue destruction in electrosurgery occurs through the transmission of electricity, which cuts tissue, destroys tissue, or cauterizes vessels.
What is the main risk of using electrocoagulation for hemostasis?
The main risk is deeper tissue damage, which may lead to unintended injury to surrounding structures.
What is the primary indication for using electrocautery in nonconductive tissue areas?
Electrocautery is used in nonconductive tissue areas like cartilage, bone, and nails because it does not transfer electric current to the target tissue.
What is the primary advantage of using bipolar techniques in electrosurgery?
Bipolar techniques provide more precise energy delivery, reducing the risk of damage to surrounding tissues.
What is the primary use of curettage and electrodessication (C+D) in electrosurgery?
Curettage and electrodessication (C+D) is commonly used for treating basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs).
What is the primary difference between electrofulguration and electrocoagulation?
Electrofulguration causes superficial damage without direct contact between the electrode and tissue, while electrocoagulation involves deeper tissue damage with direct contact of a biterminal electrode.
What is the primary risk of using electrosurgery on darkly pigmented lesions?
Darkly pigmented lesions may obscure the borders, increasing the risk of incomplete treatment and recurrence.
What is the primary mechanism of action in electrocautery?
Electrocautery works by causing protein denaturation and tissue coagulation without transferring electric current to the target tissue.
What is the primary indication for using electrolysis in cosmetic procedures?
Electrolysis is primarily used for hair removal in cosmetic procedures.
What is the primary advantage of using monoterminal electrodes in electrosurgery?
Monoterminal electrodes are simpler to use and are effective for superficial treatments without requiring a dispersing electrode.
What is the primary risk of using electrosurgery on lesions with indistinct borders?
Lesions with indistinct borders may not be completely treated, increasing the risk of recurrence.
What is the primary advantage of using electrofulguration for superficial lesions?
Electrofulguration is advantageous for superficial lesions because it causes minimal tissue damage and does not require direct contact with the tissue.
