Related Experiment Video
Updated: Jun 17, 2026
Evaluation of the Effectiveness of Longitudinal Incision for Endoscopic Submucosal Excavation of Gastric Subepithelial Lesions
Published on: April 28, 2026
"Top hat" versus conventional loop electrosurgical excision procedure in women with a type 3 transformation zone
Chumnan Kietpeerakool1, Prapaporn Suprasert, Surapan Khunamornpong
1Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. kiet_ji@hotmail.com
Objective:
To compare the "top-hat" and conventional loop electrosurgical excision procedures (LEEP) performed in women with a type 3 transformation zone to assess the rate of endocervical margin involvement.
Methods:
Women with a type 3 transformation zone randomly allocated into the conventional (n=94) and top-hat LEEP (n=86) groups were analyzed.
Results:
The rate of endocervical margin involvement in the top-hat group was lower than that in the conventional group (32.6% vs 53.2%; RR 0.36; 95% CI, 0.19-0.68; P=0.003). Among women with positive endocervical margins, women undergoing top-hat LEEP were less likely to have residual lesions compared with those in the conventional group (52.2% vs 84.1%, respectively, P=0.04). There was no significant difference in the complication rate between the top-hat and conventional groups (7.0% vs 10.6%, respectively, P=0.39).
Conclusion:
Top-hat LEEP performed in women with a type 3 transformation zone reduces the risks of endocervical margin involvement and residual diseases compared with conventional LEEP, with no significant difference in perioperative complications.
