Intrauterine Balloon Dilatation Therapy in the Prevention of Adhesion Formation After Hysteroscopic Myomectomy

Objectives

To investigate the efficacy of intrauterine balloon (IUB) dilatation therapy in the prevention of adhesion formation after transcervical resection of submucous myomas (TCRM).

Patients

The patients will be recruited from two centers, namely, the Hysterscopy Center of the Fuxing Hospital and TianTan Hospital, Capital Medical University, Beijing, China. Before the surgery all patients with suspected submucous myomas will undergo preoperative evaluations including trans-vaginal ultrasonography. The inclusion criteria include [1] women aged 18-45 years with regular 25-35 days cycles ; [2] no evidence of intrauterine adhesions at the time of surgery; [3] written consent obtained; and [4] agreement to have second-look hysteroscopy; [5] had more than one fibroids removed at the time of hysteroscopic surgery. The exclusion criteria include women who are already postmenopausal or women who have evidence of intrauterine adhesions at the time of surgery.

Study Design

After the completion of transcervical resection of submucous myomas (TCRM), recruited patients will be randomized to one of the two treatment groups by computer-generated numbers: [1] study group will have Foley-catheter intrauterine balloon dilatation therapy 2 weeks and 4 weeks after hysteroscopic myomectomy; [2] the control group will not receiveany balloon therapy. A second-look hysteroscopy will be carried out around 6 weeks after the surgery.

Procedure

Surgical procedure

The surgery will be carried out by an experienced hysteroscopic surgeons with the use of a 8.5 mm rigid hysteroscope with under 100-120 mm Hg pressure. The procedure will be performed under general anesthesia in a day surgery unit under ultrasonographic guidance. Once the type and number of myomas have been verified, the myoma will be then be bluntly dissected from the muscular layer with the tip of the resectoscope. After the myomas have been dissected from the muscular layer, they will be shaved into pieces to reduce the volume and then be retrieved from the uterine cavity with a myoma grasper.

Postoperative treatments

All patients will be treated with oral antibiotics for 3-5 days in line with local practice. Second-look hysteroscopy will be carried out 6 weeks after the initial operation. After assessment of the extent and severity of any newly formed adhesion, hysteroscopic adhesiolysis, if needed, will be carried out at the time of the second-look procedure. Immediately prior to second look hysteroscopy, a swab will be taken from the endo-cervical canal for routine bacteriological study; At the conclusion of the second look hysteroscopy, an endometrial sample will be obtained for histological study \&immune histochemical analysis including evidence of chronic endometrtitis(CD138 staining). The surgeons who perform the second-look will be blinded to the randomization.

IUB dilatation therapy

IUB dilatation therapy will be performed according to the methodology published in the literature. In brief, a Foley catheter (size 12-14fr) will be prepared by cutting the excess catheter tip protruding beyond the balloon. Once the catheter has reached the fundus, 3-5mls of saline will be slowly introduced into the balloon under ultrasound guidance, in order to directly visualize the distention of the cavity and stretching and blunt dissection of any intrauterine adhesions, if present.

Statistical Analysis

The efficacy of treating the intrauterine adhesions in the two groups will be compared using the χ2 test. The AFS score in the two groups will be compared using the Mann-Whitney U test. A p value of < 0.05 will be considered statistically significant. All statistical analysis will be carried out with the use of SPSS 21.0.

Power calculation

On the basis of the investigators own internal audit and the results of the two published retrospective cohort studies analysing the prevalence of intrauterine adhesion (IUA) formation in women undergoing transcervical resection of multiple submucousmyomas (TCRM),the investigators estimated that the adhesion formation rate in the control group to be 25% and the treatment group (balloon group) to be 5%; accepting a type 1 error of 0.05, and a type 2 error of 0.10, the number of subjects required in each arm of the randomized controlled trial would be 51. Assuming that the drop-out rate to be 10%, the total number of subject to be recruited would be 56 in each arm, that is a total of 112.

Outcome measures

The primary outcome measure will be the amount of intrauterine adhesions as measured according to the AFS score at follow-up. The secondary outcome measures will include any complications including any clinical infection and change of menstrual pattern after surgery and the need for re-operation.

Data processing and analysis

The researchers will ensure the confidentiality of sensitive data by minimizing the number of personnel who handle subject data. In addition, computer data will be encrypted as required to maximize security, while paper documents will be locked in filing cabinets, with only authorized personnel having access to the information.

Ethical considerations

IUB dilatation has been published as a novel technique with no untoward complications identified to date. The procedure will be performed according to the methodology available in the literature and the study has gained approval from the local ethical committee (Approval Notice Number:2016FXHEC-KY005).

Consent

All subjects will be given a detailed explanation of the study and sufficient time to consider participants. A written consent form will be signed by the patient and retained in the investigators confidential records.