Topic

• Introduction
• Indications
• Contraindications
• Procedure
• Coding Information

Table(s)

• Advantages and Disadvantages of Cryotherapy for Cervical Intraepithelial Neoplasia

Figure(s)

• Flat-Ended or Short Nipple-Tipped Probes
• Formation of a Rim of Ice

• Cryotherapy is a time-proven, ablative method of treating lower grades of cervical dysplasia.
• A water-soluble lubricant is applied to the probe to act as a thermocouple with the irregular surface of cervix. Rapid freeze followed by slow thaw maximizes cryonecrosis, and a freeze-thaw-refreeze cycle is more effective than a single freeze.
• After a cryoprobe is placed in contact with the cervix and activated, a ring of frozen tissue, or ice ball, extends outward. The depth of freeze approximates lateral spread of freeze. Cell death occurs when temperature falls –10°F. However, there is a ring of tissue (i.e., thermal injury or recovery zone) that freezes but does not reach the –10°F necessary for cell death. This is why it is necessary to freeze well beyond the margins of any lesions.
• Studies have demonstrated that endocervical crypt (gland) involvement of cervical intraepithelial neoplasia (CIN) may penetrate up to 3.8 mm into the cervix. A freeze that causes cell death to 4 mm should effectively eradicate 99.7% of lesions with gland involvement. Current recommendations are to produce an ice ball with a 5-mm lateral spread to accomplish this goal.
• Cryotherapy appointment should be scheduled when the patient is not experiencing heavy menstrual flow. Select the largest speculum that the patient can comfortably tolerate, and open the blades and the front end of the speculum as widely as possible without discomfort. If collapsing side walls are a problem, place a condom with the tip cut off, the thumb from a very large rubber glove with the tip cut off, or one-half of a Penrose drain over the speculum. Alternatively, tongue blades or side-wall retractors may be placed to improve exposure.
• Choice of treatment modality for cervical dysplasia is at the discretion of the health care provider. Recent National Cancer Institute/American Society for Colposcopy and Cervical Pathology consensus guidelines note that limited evidence supports any treatment modality for all grades of dysplasia. It is common practice in the U.S. to treat CIN 3 with excisional therapy (e.g., loop electrosurgical excisional procedure [LEEP]) to discover occult microinvasive cancer. Advantages and disadvantages of cryotherapy appear in Table 38-1.
• Although data are not extensive, cryotherapy apparently has little effect on fertility, labor, or pregnancy outcome. Occasionally, a patient may experience an undue amount of pain and cramping, which is usually associated with a high level of anxiety. If this can be anticipated, paracervical block before cryotherapy, oral or IM administration of benzodiazepines (e.g., 1 mg of lorazepam [Ativan] given IM), or IV sedation may be chosen for relief. These measures are seldom required. Rarely, a patient may experience a vasovagal reaction.
• The patient should refrain from sexual intercourse and tampon use for 3 wks after cryotherapy to allow cervix to reepithelialize. Excessive exercise also should likewise be discouraged to lessen the chance of bleeding after treatment.
• Most patients experience a heavy and often odorous discharge for the first month after cryotherapy. Routine cervical eschar débridement does not shorten the duration or amount of discharge and offers no significant advantage. Amino-Cerv cream may be prescribed if a heavy discharge is present after the procedure, although there is no scientific evidence of efficacy. Approximately one-third of patients restrict their activities because of the side effects of the procedure.
• First follow-up the Pap smear should not be performed for 4–6 months. Cytology can be very confusing if sampled during sloughing or regenerative phases, which take at least 3 months to complete. If the first 2 follow-up smears are normal, Pap smears can be repeated q6mos for 2 yrs after treatment. Most recurrences take place within 2 yrs of treatment.
• An alternative follow-up schedule involves replacing initial and each yearly Pap smear with colposcopic exam. If any of the follow-up tests is positive, restart workup as if there was newly diagnosed, first-time dysplasia.

• Biopsy-proven cervical intraepithelial neoplasia
• Persistent cervical discharge unresponsive to other therapies with negative Pap smears or after negative colposcopic result

Relative Contraindications

• Unsatisfactory colposcopic exam
• Lesion that extends >3–4 mm into cervical os because area of destruction may not reliably penetrate beyond this level
• Positive endocervical curettage
• Lesion that covers >2 quadrants of cervix
• Lesion that cannot be completely covered by cryoprobe
• CIN 3 lesions (relative contraindication). There may be a higher recurrence rate compared with LEEP for CIN 3 level lesions, possibly because of the greater depth of glandular involvement with CIN 3.
• Mismatch of cytologic, histologic, and colposcopic findings >2 histologic grades
• Pregnancy
• Active cervicitis
• Some physicians recommend using an excisional therapy (e.g., LEEP) for recurrent dysplasia after ablative therapy.
• Adenocarcinoma in situ (must have cold knife conization)

• Informed consent is obtained. Perform pregnancy test if there is any doubt about patient's pregnancy status. Make sure that there is adequate pressure in tank; usually, needle is in "green zone'' on pressure gage.
• Place patient in dorsal lithotomy position, and place vaginal speculum. Select probe that adequately covers entire lesion and entire transformation zone. Use only flat-ended or short nipple-tipped probes; probes with long endocervical extensions cause more cervical stenosis (Fig. 38-1). Apply water-soluble lubricant to the probe to act as thermocouple with irregular surface of cervix.
• Apply probe firmly to cervix, and make sure that it is not touching the side walls of the vagina. Start the freeze by pulling a cryogun trigger or pressing the freeze button. Within a few seconds, the probe will be frozen to the cervix. Using very light backward pressure on the cryogun, gently draw the cervix forward a few millimeters into the vagina, where probe contact with the side walls is less likely.
• A rim of ice should form and grow to a width of at least 5 mm in all quadrants (Fig. 38-2). Discontinue freeze. Release cryogun trigger or press defrost button. Wait until the probe visibly defrosts before attempting to disengage it from the cervix. The cervix should be allowed to regain pink color (usually over about 5 mins). Repeat freeze sequence as described. Second freeze is usually faster. After freeze is completed, disengage probe and remove speculum. The patient may get up, get dressed, and leave as soon as she is ready.
• Pitfall: Be careful not to allow the cryoprobe to touch the vaginal side wall, because it may stick to and freeze the vagina. The operator may quickly push the vaginal mucosa off the probe with a tongue blade or with a slight twist of the probe. If this is not done quickly, it will become more difficult as the freeze deepens, and more vaginal mucosa will be destroyed. The operator should defrost the probe just enough to release the sidewall and then continue the freeze.
• Pitfall: Fainting and light-headedness are not uncommon. Have the patient rest supine for at least several minutes and then sit up slowly.

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