Intra-operative Ultrasound Guided Laparoscopic Ovarian Cystectomy as a Method of Fertility Preservation

Background:

The use of intra-operative ultrasound has been widely implemented amongst other specialties. However, within gynaecological surgery, it is not as commonly recognized, despite evidence that it can be used as an adjunct to improving minimally invasive surgical techniques. This is primarily due to the improved visualization of the operative field, which can assist more technically difficult surgical procedures, thus minimizing intra-operative complications. The application of ultrasound guidance within gynaecological procedures have included predominantly ovarian cyst aspiration, in vitro fertilization and removal or insertion of intra-uterine devices. Although pre-operative imaging provides procedural planning, it cannot compare to the information gained from real time imaging. For example, in previous studies, intra-operative ultrasound detected more myomas during myomectomy than pre-operative transvaginal imaging. Furthermore, it provides the potential to assess lesion margins, ensuring resection of pathology is complete with negligible damage to surrounding healthy tissues. This is consistent with a recent systematic review, which also demonstrated that albeit a novel technique, amongst various case series, pathology can be safely resected without incurring injury to healthy reproductive tissue. Therefore, intra-operative ultrasound has the potential to improve surgical accuracy, reduce complications and improve patient safety. The application of intra-operative ultrasound as an adjunct to fertility sparing surgery has not been widely researched, with only a few case series reporting surgical outcomes on patients undergoing treatment for pre-malignant or malignant pathology. The aim of this study therefore, is to determine the efficacy of this surgical technique in the management of benign pathology, including the surgical resection of ovarian cysts.

Hypothesis:

Intra-operative ultrasound will prove a significant method of fertility preservation surgery, as measured by a significantly reduced decrease in Anti-Mullerian Hormone (AMH) and antral follicle count (AFC) at 3 and 6 months post-operatively, when compared to the control group.

Study Design:

This will be a multi-centre prospective cohort study carried out as a non-blinded randomised controlled trial. Women will be allocated to either a control group of laparoscopic ovarian cystectomy performed without ultrasound guidance, or to the experimental ultrasound guided laparoscopic ovarian cystectomy (UGLOC) group. All surgeons operating and women recruited to the study will be aware of which group they have been allocated to from the beginning of their participation to the study. The research team aims for equal sample sizes in both groups.

Recruitment:

Women referred to the outpatient gynaecology clinic with a suspected ovarian cyst will be asked about their clinical history and undergo a pelvic transvaginal ultrasound scan (2D and 3D ultrasonography) as part of routine clinical care. If an ovarian cyst is seen on ultrasound, it will be assessed according to local protocols based on simple descriptors and International Ovarian Tumour Analysis (IOTA) simple rules. Depending on the severity of symptoms, nature of the cyst and fulfilment of the inclusion criteria and if the woman is suitable for surgical management, she will then be invited to participate in the study. Participants will be recruited from various general gynaecology clinics, as well as specialist clinics including: ovarian cyst clinic, the IOTA and Rapid access clinics across Imperial and University College London Hospital.

Following consent of participation, the woman will be assigned to either a control or experimental group. A separate research group, not directly affiliated with the project will perform the randomisation process. The research group will print x "control group" labels and x "experimental group," in which each label is then sealed into an individual envelope. All envelopes will be numbered and issued in sequence. During the recruitment process, once the participant has given consent to participate in the trial, a member of the research team will select the envelope in sequence, which will then assign the participant to a group. This will prevent the person performing the randomisation from selecting another envelope if they are not happy with the group allocation.

For this study, it will not be necessary to postpone diagnostic procedures or treatment, and participation will not influence normal treatment.

Surgical Intervention:

The same surgeons will operate on women in both the control and experimental group. This will aim to exclude bias which may otherwise attribute findings to the surgeon operating. Surgery will be performed at Imperial Healthcare NHS Trusts and at the University College London Hospitals NHS Foundation Trust by an experienced clinician.

Data Collection:

The research team will collect the following data: Participant demographics including age, BMI, gravida, parity and gynaecological surgical history. Pre-operative data will include findings from the diagnostic transvaginal scan and measure of ovarian reserve: AMH and AFC. Intra-operative data will include transvaginal findings during surgery (in the experimental group only), such as cyst location and size or any new lesions noted. Residual ovarian volume post cystectomy will also be measured intraoperatively. Histology data will include the histological diagnosis of the ovarian cyst and volume of normal ovarian tissue excised during the cystectomy measured as per margins in mm. Outcomes following surgery including duration of surgery (mins), length of hospital stay (days) and post operative complications will be recorded.

Follow up:

Post-operatively, participants will return to their respective hospital gynaecology clinic responsible for the care and management of the ovarian cyst for follow up at 3 and 6 months. During the appointment a blood test will be taken to assess ovarian reserve by measuring the AMH level. The outpatient gynaecology nurse in clinic or research staff will be responsible for taking the blood sample and will only require one EDTA bottle (yellow top) to be filled (20-40mls). The blood samples will be processed by Imperial College Healthcare Trust laboratories or University College London Hospitals NHS Foundation Trust, depending on the site taken, and will be discarded as per local protocol once the AMH has been determined. There are no specific storage or transfer requirements outside of normal practice. Therefore, samples will be 'podded' to the labs once taken in the usual way. In addition, an ultrasound will be performed during the follow up appointment by an experienced gynaecology specialist trainee or Consultant to assess the AFC and preserved ovarian volume of tissue remaining. Any incidental findings identified on ultrasound scan of gynaecological pathology, will be managed by the responsible clinician and the participants GP will be informed by letter. Follow up appointments should take approximately 20 minutes. The two blood tests and two ultrasound scans carried out during the follow up process are considered standard clinical practice, and therefore not considered additional investigations for the purpose of this research study.

The majority of participants are likely to be discharged following their 2nd clinic appointment 6 months post- surgery, whereby no further involvement in the study is required. If a participant becomes pregnant during the follow up period, clinic appointments will be deferred to 3 and 6 months post-partum.