Comparison Between 200 μg and 800 μg of Misoprostol for Cervical Ripening Prior to Operative Hysteroscopy: A Study Protocol for A Randomized Controlled Trial
Background: Hysteroscopy, a minimally invasive procedure, has been increasingly used to treat disorders of the cervical canal and uterine cavity. However, difficulties related to the insertion of the hysteroscope through the cervical canal still remain. Although there are reported advantages in reducing cervical resistance with the use of misoprostol for cervical ripening, systematic reviews highlight the need to determine the optimal dose. This study was designed to compare two groups of
... two groups of patients submitted to cervical dilatation prior to operative hysteroscopy and pre-treated with either 200 µg or 800 µg of misoprostol for cervical ripening. Methods: A randomized, quadruple-blind clinical trial with patients submitted to cervical dilatation prior to operative hysteroscopy at university teaching hospitals in Recife, Pernambuco, Brazil. After the internal review boards of the participating institutes had approved the study protocol, data collection began on November 7, 2019, with expected completion on November 1, 2020. Patients included in the study following the informed consent process are randomly allocated to one of two groups, the first allocated to use 200 μg misoprostol and the second to use an 800-μg dose. In both groups, misoprostol will be administered vaginally 10-12 hours prior to operative hysteroscopy. The groups will be compared in relation to intraoperative and postoperative outcomes based on the following endpoints: baseline cervical dilatation, cervical length, degree of difficulty, duration of cervical dilatation, failure to dilate, adverse events and surgical complications. The chi-square test of association, Fisher's exact test and the Mann-Whitney test will be used to compare the groups, with an alpha error of <5% being considered significant. Discussion: The findings of this study will contribute towards establishing the optimal misoprostol dose for cervical ripening prior to operative hysteroscopy, ultimately facilitating hysteroscope insertion through the cervical canal. A gap will be filled in the currently available literature, providing future preoperative guidance. The 800-μg dose of misoprostol is expected to reduce resistance in the cervix and shorten the time until achieving cervical dilatation, delivering a less traumatic procedure for the patient. Therefore, the study is relevant for surgeons in this field, for the scientific community and, particularly, for patients. Trial registration: Clinical Trials Register: NCT04152317. Registered on November 5, 2019. URL https://clinicaltrials.gov/ct2/show/study/NCT04152317.