Persistence of dysmenorrhea and nonmenstrual pain after optimal endometriosis surgery may indicate adenomyosis

Abstract

To evaluate whether persistence of pelvic pain after excision of endometriosis was associated with adenomyosis as defined by a thickened uterine junctional zone (JZ) on magnetic resonance (MR) imaging. Prospective clinical trial. Government research hospital. Fifty-three women with chronic pelvic pain. Preoperative MR imaging to measure uterine JZ thickness, surgical excision, and pathologic diagnosis of endometriosis. Those with biopsy-proven endometriosis were randomized to raloxifene or placebo. Visual analog scale (VAS) was used to rate dysmenorrhea and nonmenstrual pain severity before surgery and 3 months later. Comparison of JZ thickness and pain severity before and 3 months after surgery in women with endometriosis controlling for medical treatment. Forty of the 53 patients had biopsy-proven endometriosis, and 6 of these 40 women with endometriosis had a thickened JZ. Overall, dysmenorrhea at 3 months was positively correlated with preoperative JZ thickness (r = 0.47, P=.01). Dysmenorrhea pain severity showed no significant decrease in those patients whose JZ measured >or=11 mm compared with those with JZ <8 mm (P<.0001; VAS decreased 4.3 +/- 0.6), or >or=8 and <11 mm (P<.02; VAS decreased 4.8 +/- 1.3). Nonmenstrual pain severity was correlated with JZ thickness (r = 0.51, P=.004) at 3 months with a significant decrease in nonmenstrual pain only in women with a JZ <8 mm (VAS decreased 4.0 +/- 0.7, P<.0001). The association between dysmenorrhea and nonmenstrual pain reduction and thinner JZ remained after controlling for medical treatment. Following surgical excision of endometriosis, chronic pelvic pain was significantly more likely to persist with JZ thickness >11mm on preoperative MR imaging. This suggests that myometrial JZ abnormalities or adenomyosis may contribute to chronic pelvic pain in women with endometriosis.