30 - 206 - CRYOSURGERY AND ELECTROSURGERY

Question 1

cryogen of choice for treating benign and malignant neoplasm

Answer 1

liquid nitrogen

• boiling point of −195.8 Celsius
• has the lowest temperature of all the common cryogens, causing rapid freeze of treated tissue

Question 2

MOST sensitive to the destructive effects of cryosurgery

Answer 2

Melanocytes

Question 3

LEAST sensitive to the destructive effects of cryosurgery

Answer 3

fibroblasts

Question 4

refers to the use of extreme cold to destroy cells of abnormal or diseased tissue

Answer 4

Cryosurgery

Question 5

refers to the study of the effects of subzero temperature on living systems

Answer 5

Cryobiology

Question 6

causes intracellular ice crystal formation with the disruption of electrolytes and pH changes

Answer 6

Rapid freezing

• Therefore, tissue effects and cell death are most readily achieved when tissue is frozen rapidly.
• During thawing, recrystallization occurs when ice crystals fuse to form large crystals that disrupt cell membranes.
• As the ice melts further, the extracellular environment becomes hypotonic, causing water to infuse into cells and cause cell lysis.
• The longer the thawing time, the greater the damage to cells because of increased solute effect and greater recrystallization

Question 7

causes extracellular ice formation and less cell damage

Answer 7

slow freezing

Question 8

major mechanism of injury from cryosurgery

Answer 8

• After freezing, stasis within the vasculature occurs.
• This **loss of circulation and resultant anoxia **is a major mechanism of injury from cryosurgery.

Question 9

cell destruction of melanocytes occur at what temperature?

Answer 9

−4°C to −7°C (24.8°F to 19.4°F)

Question 10

cell destruction of keratinocytes occur at what temperature?

Answer 10

**−20°C to −30°C **(−4°F to −22°F)

Question 10

cell destruction of fibroblasts occur at what temperature?

Answer 10

−30°C to −35°C (−22°F to −31°F)

Question 10

cell destruction of malignant lesions occur at what temperature?

Answer 10

−50°C to −60°C (−58°F to −76°F)

Question 10

Absolute contraindications to cryosurgery

Answer 10

• lesions that require histopathology for diagnosis
• recurrent nonmelanoma skin cancers.

Question 11

Relative contraindications to cryosurgery

Answer 11

• cold urticaria,
• abnormal cold intolerance,
• cryoglobulinemia, or cryofibrinogenemia, or
• tumors with indistinct borders or darkly pigmented features

Question 12

Risks and potential complications of cryosurgery

Answer 12

• pain
• bleeding
• pigmentation change
• nerve damage
• scarring
• alopecia
• insufflation of soft tissue

Question 13

most disconcerting complication following cryosurgery

Answer 13

Hypopigmentation or hyperpigmentation

Question 14

Freeze times longer than how many seconds may result in alopecia?

Answer 14

20 seconds

Question 15

reactions expected from treated areas within 24 hours posttreatment of cryosurgery

Answer 15

Edema, vesicles, bullae, and weeping

Question 16

n general, superficial lesions should have a clinical freeze margin of how many mm?

Answer 16

2 - 3 mm

Question 17

malignant or deeper lesions should have a clinical freeze margin of how many mm?

Answer 17

5 mm

Question 18

technique that uses the transmission of electricity to cut tissue, destroy tissue, and cauterize vessels

Answer 18

Electrosurgery

Question 19

• uses a damped sine wave, high-voltage, low-amperage alternating current to generate a spark from a monoterminal electrode to the tissue via the air
• There is no contact between the electrode and the tissue

Answer 19

Electrofulguration

Question 20

• This modality is the least tissue damaging of all of the high-frequency electrosurgery techniques, and results in rapid tissue healing.
• Most of the tissue damage is superficial, primarily involving the epidermis.

Answer 20

Electrofulguration

Question 21

• damped sine wave, high-voltage, low-amperage alternating current to generate a current from direct contact of a monoterminal electrode to the tissue
• Superficial tissue damage occurs as** heat is transferred to tissue**, causing cell death.

Answer 21

Electrodessication

• The extent of tissue damage is directly related to electrode contact time with the skin.
• Although skin injury is greater with electrodessication compared to electrofulguration, most of the tissue damage remains superficial

Question 22

* uses a moderately damped sine wave, low-voltage, high-amperage alternating current to generate a current from **direct contact of a biterminal electrode** to the tissue. * Tissue damage is deeper than with electrofulguration and electrodessication, providing tissue coagulation through **the generation of heat in the tissue**.

Answer 22

Electrocoagulation ## Footnote * Another distinguishing feature of electrocoagulation is the involvement of the patient within the circuit. * This allows the use of a lower voltage and higher amperage to generate more coagulation.

Question 23

* uses a heating filament tip connected to a low-voltage, high-amperage direct current, usually a battery. * Heat is transferred from the filament to the target tissue, causing protein denaturation and tissue coagulation.

Answer 23

Electrocautery

Question 24

* undamped or slightly damped sine wave, low-voltage, high-amperage alternating current to **cut tissue with minimal peripheral heat damage**

Answer 24

Electrosection ## Footnote * The “Bovie” knife incorporates a blended undamped and damped sine wave that provides both cutting and coagulation at the same time

Question 25

There is no electric current transfer to the target tissue, and the patient is not part of the circuit loop.

Answer 25

Electrocautery

Question 26

* most used for patients with **pacemakers or implantable cardiac defibrillators (ICDs)** who are high-risk candidates for receiving electrosurgery. * because patients are not part of the circuit loop, it is useful for nonconductive tissue areas of the body, such as the** cartilage, bone, and nails.**

Answer 26

Electrocautery

Question 27

* uses low-voltage, low-amperage direct current from a **negative electrode to the positive electrode** * The negative electrode is applied to the target tissue where electrons are released. * The electrons interact with the tissue to produce** sodium hydroxide **and **hydrogen gas** resulting in tissue **liquefaction**. * **Acids** are produced at the **positive electrode **resulting in tissue **coagulation**.

Answer 27

Electrolysis ## Footnote The main use of electrolysis is for hair removal.

Question 28

With the exception of what electrosurgical techniques, electrosurgical units used in dermatologic procedures have high-frequency alternating current

Answer 28

electrocautery or electrolysis

Question 28

refers to the use of a treatment electrode without an indifferent or dispersing electrode

Answer 28

Monoterminal ## Footnote The dispersing electrode (grounding pad) should be placed in a location that directs the current pathway away from the cardiac device (usually the right lower leg). If a pedal is used, it should be placed near the surgeon’s feet.

Question 29

refers to the use of both treatment and indifferent electrodes.

Answer 29

Biterminal ## Footnote The dispersing electrode (grounding pad) should be placed in a location that directs the current pathway away from the cardiac device (usually the right lower leg). If a pedal is used, it should be placed near the surgeon’s feet.

Question 30

denotes 1 tip in electrosurgical unit

Answer 30

Monopolar

Question 31

denotes 2 tips in electrosurgical units

Answer 31

bipolar

Question 32

most common application of electrosurgery

Answer 32

maintaining hemostasis in the operative field

Question 33

Coagulation can be achieved using what electrosurgical techniques?

Answer 33

electrofulguration, electrodessication, or electrocoagulation ## Footnote * direct application of the electrode to the bleeding vessel. * This provides conduction of heat to the vessel, resulting in tissue coagulation

Question 34

electrosurgical technique that is an effective treatment modality for papular or plaque-like tumors of the epidermis, such as seborrheic keratoses, verrucae, dermatosis papulosis nigra, molluscum, or flat warts

Answer 34

Electrodessication

Question 34

indications for Curettage and electrodessication (C+D) for BCC and SCC

Answer 34

* Tumors should be primary; * have distinct clinical borders; * be located on sites of low recurrence, such as the trunk, extremities, or non-”H”-zone regions of the face; * have a superficial or nodular histologic subtype; and * have a diameter of less than 1 cm on the face and less than 2 cm on the trunk and extremities.

Question 35

Tumors not acceptable for C+D

Answer 35

* indistinct borders, * tumors on the “H”-zone of the face, * tumors with an aggressive histologic pattern, * tumors with high metastatic potential, * tumors that require histologic diagnosis.