Numerous studies—some of them randomized—have failed to find major differences in cure rates of cervical intraepithelial neoplasia (CIN) among cryotherapy, laser treatment, and loop electrosurgical excision. The investigators have, in the past 2 decades, treated CIN in 2107 women by gadolinium (Nd-YAG) laser conization that vaporized the base. The procedure took only 12 minutes on average. Just over 10% of women lost more than 20 mL of blood during the procedure. Approximately 7% of patients, 98% of them postmenopausal, had cervical obstruction during follow up.
Either no CIN or grade 1–3 CIN was found in 92.8% of cone specimens, whereas 7.2% exhibited invasive disease. Women lacking invasive disease were followed between 16 months and 21 years. The rate of incomplete excision was 12.3% in patients having CIN in the cone specimen, but the rate of persistent or recurrent disease was only 1.2%. Of 230 patients with postoperative CIN and positive surgical margins, 83.5% had no abnormal cytologic or colposcopic abnormalities during follow up. In contrast, preoperative underdiagnosis of the biopsy results did increase the risk of incomplete excision and failure. The odds ratio for incomplete excision was 1.51 (95% confidence interval [CI], 1.13–2.02) and that for failure was 3.20 (95% CI, 1.44–7.13).
Combining laser conization with vaporizing the base is an effective means of treating CIN because it detects otherwise unexpected invasive disease.