Hysteroscopy is a minimally invasive diagnostic and therapeutic procedure for various intrauterine conditions such as endometrial polyps, myomas, intrauterine adhesions, and retained products of conception. While the diagnostic procedures are often performed without anaesthesia (in the office setting), the operative procedures are performed either under general anaesthesia in the operative room, or without anaesthesia (in the office setting), depending on the patients' characterises and preferences, and surgical indications. In general, operative hysteroscopy without anaesthesia is offered to patients willing to undergo an awake operative procedure who have relatively small intrauterine pathologies (such as endometrial polyps and retained products of conception up to1.5 cm in diameter), mild intrauterine adhesions, and for removal of retained intrauterine device. In this setting, 80% to 100% of operative procedure without anesthesia can be successfully completed. The main reasons for inability to successfully complete operative hysteroscopy without anesthesia are patients' discomfort and limited visibility of the uterine cavity.

During hysteroscopy, distention of the uterine cavity with a distention medium is required to allow for optimal visualization. The uterine distention is an essential component of hysteroscopy, because the uterine cavity is a potential space which is normally collapsed. The most common distention medium for diagnostic and operative hysteroscopy is 0.9% normal saline. When the procedure is performed without anesthesia (i.e., in the office setting), some of the discomfort perceived by the patient is caused by the distention of the cavity. Obviously, longer procedures and the use of higher pressure of the distention medium are associated with greater patients' discomfort. On the other hand, the use of higher pressure may allow for better visualization of the uterine cavity, which may contribute to higher success rates of operative hysteroscopy without anesthesia. However, the optimal normal saline pressure which allows for adequate visualization of the uterine cavity and successful completion of operative hysteroscopy without anesthesia with acceptable patients' discomfort has not been determined to date. Previous studies have described the use of intrauterine pressure of normal saline for operative hysteroscopy without anesthesia in the range of 80 mmHg up to 150 mmHg.

In the current study, the investigators will compare the use of two different pressure setting for normal saline during operative hysteroscopy without anesthesia, with the aim of investigating the successful completion of the procedure, the surgeons' impression and the patient's discomfort, with the aim of determining the optimal pressure setting for these procedures.

Participation in the study will be offered to patients referred for operative hysteroscopy without anesthesia in the office setting in the outpatient service of the division of minimally invasive gynecologic surgery at the Shamir medical center department of obstetrics and gynecology. The indication for the surgery, surgical technique and instrumentation, and pre- and postoperative follow up will be identical to the standard procedures performed in our department in these cases. Patients will sign the standard informed consent form for operative hysteroscopy. Participants will be randomly assigned into the low pressure or the high pressure groups. The surgeons and the patients will be blinded to the pressure setting which will be set up by the assisting nurse. Following the procedure, the surgeon will fill a questionnaire regarding the feasibility of the procedure and the uterine cavity visibility (appendix 1). The intraoperative pain will be determined using a Visual analog scale (VAS).