Needle versus loop diathermy excision of the transformation zone for the treatment of cervical intraepithelial neoplasia: a randomised controlled trial.

Abstract

To determine whether lower rates or incomplete resection of cervical intraepithelial neoplasia (CIN) may be achieved by needle excision of the transformation zone (NETZ) than with loop excision (LLETZ). A prospective randomised controlled trial. A gynaecological oncology centre and a teaching hospital in West London. Four hundred and four women due to receive treatment for suspected CIN. Women were randomised to receive either LLETZ or NETZ. The study was designed to demostrate a difference in the proportion of women with clear histological margins of 82% for LLETZ compared to 94% for NETZ with 90% power at a 5% significance level, allowing for absence of CIN in the treatment specimen in 15%. Four randomised women were excluded from the analysis, as they were ineligible for the study. Three hundred and forty-seven (87%) had CIN in the treatment specimen and could be included in the analysis of excision margins. More women in the NETZ arm had clear histological margins (84.8%vs 75%, (P= 0.03). The median volume of specimens in the NETZ arm was 739 mm(3) larger (P= 0.33) and they were less likely to be removed in multiple pieces (2.5%vs 29.5%, RR 0.09, 95% CI 0.04 to 0.20). Needle excision took longer to perform (median treatment time 210 vs 90 seconds, P<0.0001) and surgeons more often reported the procedure as 'difficult' (9.5%vs 3.0%, RR = 3.17%, 95% CI 1.33 to 7.58). No difference in peri-operative or post-operative complication rates could be demonstrated between the two groups. NETZ is more likely to produce a specimen in one piece and with clear margins compared to LLETZ.