Evaluation of 3D Translabial Ultrasound Imaging for Pessary Size Estimation

Symptoms of female pelvic floor dysfunction, such as incontinence and pelvic organ prolapse, can be alleviated by using pessaries, which are passive medical devices that are inserted in the vagina to support the pelvic organs. Currently, pessaries are fit through trial and error after manual examination, the accuracy of which depends on the physician's expertise level.

The objective of this study is to evaluate the feasibility of using 3D translabial ultrasound imaging of the vagina at various distension volumes to predict the pessary size for successful fit. Ultrasound images will be obtained using commercially available 3D ultrasound probes (Philips, Netherlands), as well as a commercially available 2D ultrasound probe (Philips, Netherlands), which is linearly scanned to capture a 3D volume. The linear scanning will be performed by attaching the 2D probe to a motorized hand-held scanner, which is used to tilt and move the probe to acquire images. Please note that the hand-held scanner does not come in contact with the patient. To distend the vagina, a sterile bag is inserted in the vagina and gradually filled with water using a commercially available urodynamic system (Laborie, Canada) until the vaginal capacity is reached, without causing any discomfort to the patient. This image acquisition technique, previously reported in the literature, is referred to as 3D ultrasound vaginal manometry in this study.

To achieve the objective of this project, 35 pelvic organ prolapse patients, who (i) are current pessary users, (ii) can perform self-care of the pessary, and (iii) can provide informed consent, will be invited to participate in the study. Patients will be asked to remove their pessary prior to ultrasound imaging. Then, 3D ultrasound vaginal manometry will be performed, using the technique described above. Ultrasound images will be analyzed once data acquisition is completed. The size of the pessary estimated from ultrasound images will be compared with the actual pessary size used by the patient.