Reproducible assessment of vaginal and rectal mucosal and skin blood flow:laser doppler fluximetry of the pelvic microcirculation

Pelvic venous congestion is a common cause of chronic pelvic pain in women of reproductive age. Although this condition represents a functional distur bance of the pelvic circulation which is related to the menstrual cycle, it s aetiology remains unknown. Indirect techniques demonstrate that the vasoc onstrictive reflex response of the microcirculation of the foot to a rise i n venous pressure is attenuated throughout the menstrual cycle. We wished t o develop a simple and noninvasive direct measure of pelvic blood flow to a id diagnosis of this condition. Laser doppler blood flux measurements of th e skin of the big toe and of the vaginal and rectal mucosa in the follicula r and luteal phases of the menstrual cycle in 12 healthy asymptomatic preme nopausal women (mean age 30 years) with regular cycles and in four healthy asymptomatic postmenopausal women (mean age 59 years) were carried out both in the supine position and in response to 40 degrees head-up tilt. The coe fficient of variation of resting vaginal flux was lower for measurements in postmenopausal women (0.04) and in premenopausal women in the follicular p hase (0.07) compared with those in the luteal phase (0.16). At rest, vagina l blood flow was higher than rectal and skin flux in both premenopausal and postmenopausal women. In the follicular phase a decrease in flow was obser ved in response to head-up tilt in the skin (-32.0%), vagina (-34.3%) and r ectum (-9.4%). In the luteal phase this reflex was attenuated at these thre e sites (-8.6%, +6.7% and +7.4% respectively). There were no significant re flex changes in postmenopausal women. Thus laser doppler fluximetry is a re producible method for comparing the flux of blood in the microcirculation o f the skin and of the vaginal and rectal mucosa. The skin is the least sens itive site for testing vascular reactivity in response to cyclical changes. The vaginal and rectal microcirculations are the most sensitive sites for testing visceral cyclical reactivity, and have the advantage of direct anat omical relevance. The follicular phase of the menstrual cycle is associated with greatest vascular reactivity and is the most appropriate phase during which to test for abnormal vascular responses.