Endometriosis Pain

"Thermal stimuli: The Thermal Sensory Analyzer will be used to deliver heat and cold stimuli. All targeted stimulus temperatures will be less than 50°C, and participants will be free to remove their arm or leg at any time from the thermode. Noxious cold stimuli will also be delivered with a plastic water bath or an electronic electronic temperature-controlled water bath. Participants will be free to pull out of the water bath at any time.~Pressure stimuli: Pressure stimuli will be applied by using a handheld algometer. These devices have a round probe that allows quantifying the amount of pressure that is being applied by real-time visual feedback to control and monitor applied pressure rates. Pressure will be applied to the lower leg, volar forearm, or trapezius.~Mechanical stimuli: A set of standardised von Frey filaments (0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128 and 256mN). The contact area of the hairs with the skin is of uniform size (\<1 mm²) and texture."

"Pain ratings- Pain intensity and pain unpleasantness ratings will be assessed~Pain thresholds to heat, cold and/or pressure will be tested and participants will be instructed to press a button the first moment they feel pain.~Temporal summation- participants will rate the pain evoked by a single pinprick stimulus and by a series of 10 identical pinprick stimuli.~Conditioned pain modulation (CPM) efficiency - CPM testing includes the application of a test stimulus without conditioning (heat or pressure stimuli) and a subsequent application of the same test stimulus together with a conditioning stimulus (cold stimulus).~Offset analgesia will be assessed using the three-temperature method (T1°C 5s, T1+1°C 5s, T1°C 20s). During the OA paradigm, real time pain intensity ratings will be obtained~Cold pain tolerance will be assessed by having participants immerse their hand or foot in a cold water bath. Tolerance will be defined by the time of hand/foot withdrawal."

Blood (approximately 2 tablespoons), urine and saliva samples will be collected and sent to ZRT Laboratory, LabCorp, or internal Washington University lab for analyses of sex hormone levels (e.g., testosterone, estradiol, progesterone). Additional samples will be stored in a biobank for future processing.

During the surgery, biopsies will be collected from the endometriosis lesions as well as from a healthy peritoneum. If there are no endometriosis lesions, biopsies will be taken of two common locations where endometriosis lesion grows (the infra-ovarian fossa). The lesions will be characterized based on their appearance and invasiveness of the lesions (i.e., powder-burn lesions, nonclassical red or white lesions, and superficially or deeply infiltrating (\>5mm) lesions). In addition, surgery-related data such as the incision size, type of anesthesia, pain ratings after the surgery, analgesic medication after the surgery, and side effects will be documented. Blood, saliva, urine, and samples will be collected for hormonal analyses or stored in a Biobank for future analyses.