Minimal conization with carbon dioxide laser for treatment of cervical intra-epithelial neoplasia

3,100 non-pregnant women and 85 pregnants were miniconized during the 15-year period ending 1994 . The outpatient procedure of minimal conization using a freehand-guided, high power 60W carbon dioxide laser focused to 0.1 mm in spot-size, giving high power density 165,000 W/cm2, produces single-piece tissue specimens for histological examination. The procedure is performed under local anaesthesia to excise from the uterine cervix a single shallow conical tissue specimen 5 mm high (range 3-8 mm), or during pregnancy, 7 mm (range 5-15 mm). Following this removal a routine cervical curettage is added.

This technique is suitable for simultaneous diagnosis and treatment of cervical intraepithelial neoplasia CIN I-III in non-pregnant patients, but also during pregnancy for selected cases of CIN III with extensive colposcopic signs of lesions or suspected lesions.

Patient discomfort, bleeding complications, infection or vaginal discharge and thermal damage of resection lines on the tissue specimen were all minimal. Analysis of the subsequent pregnancy outcome showed that miniconized subjects had no significant pregnancy complications and the same preterm birth ratio as controls (8.0%) measured for age and parity.

Histopathological examination of the minicone specimen revealed microinvasive or invasive carcinoma in 1.2% of the non-pregnant subjects and 13.3% during pregnancy. Pregnancies were salvaged and radical cancer treatment could be postponed until delivery. During pregnancy, there were no complications attributable to the conization procedure and no adverse effects either during pregnancy or at delivery.

The primary cure rates were 90.8% during pregnancy and 96.1% in the non-pregnant subjects. No suddenly occurring carcinoma was observed during the follow-up period. Cumulative risk of recurrence for all forms of CIN was 3.2% at year 15, which minimizes the need for frequent check-ups. This would roughly halve the cost of CIN work-up.

The miniconization procedure using 60W high power density laser is a safe, even during pregnancy, effective treatment for CIN and early forms of microinvasive carcinoma. Invasive carcinoma can be detected early and should be treated without delay. This procedure also offers psychological relief to ever anxious patients with CIN.