Microcolpohysteroscopic tailoring of cervical conization

The ideal cone biopsy should have its apex just above the transformation zone to ensure removal of all abnormal squamous and metaplastic epithelium in the endocervix, with only minimal normal glandular tissue included. The microhysteroscope has been shown to be useful in identifying the upper limit of the transformation zone within the canal, and this distance from the external os can be measured. However, this technique has not been evaluated to determine whether it can tailor cone length to this predetermined measurement. We report an observational analysis of 176 consecutive conizations in patients with colposcopically proved extension of abnormal epithelium high into the cervical canal. In 162 cases, the distance of the transformation zone from the external os could be measured with the microhysteroscope and its endocervicometer, permitting an attempt to tailor the cone length to this measurement plus a safety margin of 5 mm. There was good correlation between the intended cone length and the excised cone length, with 85% of the excised cones falling within 5 mm above or below the intended measurement. In 153 instances (94.4%), the excised cones had clear endocervical margins. Thus, tailoring of the cone length to the hysteroscopically determined measurement is feasible, thereby increasing the chances of complete excision while limiting cone size to the required minimum.