Main findings:
Extrinsic subtype with FUAS alone might inform earlier recurrence of adenomyosis after FUAS.
In this retrospective cohort study, we established that classification 2 was the optimal one to identify the dysmenorrhea relief and recurrence of adenomyosis. The extrinsic subtype of classification 2 correlated to an earlier onset of recurrence after FUAS alone. However, there was no association between classifications based on MRI and FUAS efficacy combined with GnRH-a/mirena. Besides, our study also informed that FUAS combined with GnRH-a/mirena might be a good choice to decrease the recurrence rates of adenomyosis after FUAS.
Our results were in agreement with the results of Kishi et al5, suggesting that extrinsic subtype was more prone to suffering from dysmenorrhea and higher chance of concomitant endometriosis, especially in the posterior lesion of myometrium in patients with adenomyosis. We found no significant differences in age among four subtypes, and age was considered an independent factor for the relapse of adenomyois after FUAS. Our results were also in consistent with the finding of Kobayashi et al17, suggesting that patients in external and diffuse subtypes had more chance of dysmenorrhea and coexistence with endometriosis. Subsequently, Gong et al9 tried to explore the FUAS efficacy based on MRI, finding that there were significant differences between menstrual pain scores and menstrual blood volume scores before and 18 months after FUAS among different subtypes, while there were no significant differences among subtypes in menstrual pain 18 months after FUAS. The results were partially different from our results of the relief rates of dysmenorrhea for the the usage of union MRI classification criterion in evaluating FUAS efficacy. In our study, we compared five common criteria MRI for their ability to evaluate FUAS efficacy, found that classification 2 was the optimal one for evaluating FUAS efficacy, and identified that extrinsic subtype of classification 2 correlated to an earlier onset of symptomatic recurrence after FUAS alone.