Negative margins in an excisional specimen do not mean the lesion is completely excised.
4.
If future fertility is desired, conservative excisional management is acceptable.
The overall failure rate of excision is less than 10%. Margin status is a useful clinical predictor of residual disease as is endocervical sampling at the time of excision.
5.
If a conservative excisional procedure is performed and margins are involved or the endocervical sample at the time of excision shows AIS or CIN, reexcision is recommended.
6.
A reassessment at 6 months using a combination of cytology, colposcopy, HPV DNA testing, and endocervical sampling is acceptable. Long-term follow-up is recommended for women who do not undergo hysterectomy for AIS.
Cryotherapy Cryotherapy destroys the surface epithelium of the cervix by crystallizing the intracellular water, resulting in the eventual destruction of the cell. The temperature needed for effective destruction must be in the range of (–20◦ to –30◦C). Nitrous oxide (–89◦C) and carbon dioxide (–65◦C) produce temperatures below this range and, therefore, are the most commonly used gases for this procedure.
The technique believed to be most effective is a freeze-thaw-freeze method in which an ice ball is achieved 5 mm beyond the edge of the probe. The time required for this process is related to the pressure of the gas; the higher the pressure, the faster the ice ball is achieved. Cryotherapy is an effective treatment for CIN with very acceptable failure rates under certain conditions (94–97). It is a relatively safe procedure with few complications. Cervical stenosis is rare but can occur. Posttreatment bleeding is uncommon and is usually related to infection.
Cure rates are related to the grade of the lesion; CIN 3 has a greater chance of treatment failure (Table 19.4). Townsend showed that cures are related to the size of the lesion; those covering most of the ectocervix have failure rates as high as 42%, compared with a 7% failure rate for lesions less than 1 cm in diameter (99). Positive findings on endocervical curettage can reduce the cure rate significantly. Endocervical gland involvement is important because the failure rate
Table 19.4 Results of Cryotherapy for Cervical Intraepithelial Neoplasia (CIN) Compared with Grade of CIN
Table 19.5 Success Rate for Laser Vaporization
Loop electrosurgical excision is a valuable tool for the diagnosis and treatment of CIN (106– 116). It offers the advantage of performing an operation that is simultaneously diagnostic and therapeutic during one outpatient visit (100–105,117–122).
The tissue effect of electricity depends on the concentration of electrons (size of the wire), the power (watts), and the water content of the tissue. If low power or a large-diameter wire is used, the effect will be electrocautery, and the thermal damage to tissue will be extensive. If the power is high (35–55 watts) and the wire loop is small (0.5 mm), the effect will be electrosurgical, and the tissue will have little thermal damage. The actual cutting is a result of a steam envelope developing at the interface between the wire loop and the water-laden tissue. This envelope is pushed through the tissue, and the combination of electron ﬂow and acoustical events separates the tissue. After the excision, a 5-mm diameter ball electrode is used, and the power is set at 50 watts. The ball is placed near the surface so that a spark occurs between the ball and the tissue. This process is called electrofulguration, and it results in some thermal damage that leads to hemostasis. If too much fulguration occurs, the patient will develop an eschar with more discharge, and the risk for infection and late bleeding will be higher.