Previous studies have indicated that MEA is an alternative to hysterectomy for patients requiring treatment for hypermenorrhea caused by submucous myomas.1–3 This procedure has gained popularity in Japan, where it has been covered by the national health insurance program since 2012. Although MEA can safely and effectively treat submucous myomas, some patients may experience recurrent hypermenorrhea after the procedure and require additional treatment. This is believed to be caused by endometrial regeneration over time as the uterine cavity expands because of post-procedural fibroid growth. The present study evaluated the efficacy and safety of the combination of MEA and TCR under hysteroscopic guidance for women with submucous myomas. The patients experienced dramatic improvements in their hypermenorrhea symptoms and a significant increase in their circulating Hb concentrations. Furthermore, none of the women experienced recurrence of hypermenorrhea during the follow-up period.
Submucous myomas deform the uterine cavity, which can complicate the endometrial ablation process, depending on the shape of the microwave applicator. A resectoscope can be used for pre-ablation excision to improve the outcomes of MEA by smoothing the irregular inner surface, although it is important to be aware of potential issues regarding the scope of fibroid resection during this step. Problems are unlikely in patients who have a sufficiently thick residual myometrium, even if the submucous myoma is completely removed, although excessive thinning is possible if complete myoma resection is attempted. Thus, the Japanese clinical practice guidelines indicate that MEA requires a myometrial thickness of ≥ 10 mm, which is intended to prevent damage to the surrounding organs.5 Therefore, the scope of the TCR must be limited to partial resection before MEA if there is a risk of excessively thinning the uterine musculature. We reviewed the patients’ TCR procedures and noted that only 6 patients underwent partial resection, although these patients experienced no recurrence and reported the same improvements in their clinical symptoms (vs. patients who underwent complete resection). The efficacy of the combined procedures can be attributed to the reduction in the fibroid mass and the use of a hysteroscope after the MEA to evaluate the uterine cavity and perform cauterization for sites with inadequate ablation.
The levonorgestrel-releasing intrauterine system (LNG-IUS) is another minimally invasive treatment for hypermenorrhea. This system provides promising outcomes, based on a > 50% reduction in menstrual flow (vs. the preoperative volume) experienced by 84.8% of patients and amenorrhea only occurring in approximately 20% of patients.6 Based on our findings, the MEA procedure appears to be more effective than the LNG-IUS, although a direct comparison is precluded because we only used subjective VAS ratings to evaluate menstrual flow. Nevertheless, from a long-term perspective, the effects of MEA may be more stable, as only 21% of patients who undergo MEA require another treatment for recurrent hypermenorrhea, while re-treatment is required for 42% of patients who receive the LNG-IUS.6,7 Furthermore, the LNG-IUS could potentially slip out of place in a uterine cavity that has been deformed by the presence of submucous myomas. Therefore, we suggest that the combination MEA and TCR is a more effective treatment option for hypermenorrhea caused by submucous uterine myomas.
The concurrent use of a resectoscope with MEA permits a histopathological characterization of the lesion, which is not possible if MEA is performed alone. We have also previously reported that abnormal findings were observed in endometrial specimens that were collected via endometrial total curettage during MEA, despite these patients having initially negative results for uterine malignancy from cytodiagnostic and histological screening before the MEA.8 The present study also identified 2 patients with uterine malignancy, which was confirmed based on the histopathological findings from specimens that were excised during the combination of TCR and MEA, despite the preoperative diagnosis being hypermenorrhea caused by submucous uterine myoma. Similarly, histopathological examinations of the TCR specimens can be useful for identifying uterine malignancies.
It is important to consider the safety of MEA, as complications include heat injury to the pelvic organs, fluid retention in the uterus (because of cervical stenosis or the ablated endometrium), hematometra, pelvic inflammation (e.g., endometritis because of ascending infection), and pyometra.9 However, we did not detect any of these complications, which may be related to the use of a resectoscope to evaluate the endometrial lining immediately after MEA. This step allowed for the maximum removal of the necrotic tissue left over by ablation, and we believe that it can improve the safety of MEA by reducing the rate of complications.
Although MEA is not indicated for treating dysmenorrhea and was not originally expected to alleviate its symptoms, some studies demonstrate its effectiveness in treating this condition.10,11 Our patients reported improvements in dysmenorrhea as soon as their first menses after MEA. We speculate that this was a secondary effect of improvements in hypermenorrhea, as reductions in menstrual volume were accompanied by less severe dysmenorrhea. Thus, MEA might be effective for reducing dysmenorrhea that is associated with hypermenorrhea caused by uterine myomas.
Our patients were highly satisfied with the MEA, based on an average VAS score of 9.5 ± 0.89 out of 10 points. Furthermore, most patients continued menstruating, although amenorrhea was reported by 10 patients (31.3%). Thus, we reckon that women with hypermenorrhea may desire a reduction, but not necessarily complete elimination, of menstrual flow while preserving their uterine function. The safety and efficacy of MEA in combination with TCR may also contribute to the patients’ satisfaction.
Further studies are needed to consider various issues related to whether a combination of MEA and TCR can effectively treat hypermenorrhea secondary to uterine myomas. For example, hypermenorrhea outcomes should be considered in cases where the fibroids do not protrude into the uterine cavity. Furthermore, long-term follow-up is needed to clarify the hypermenorrhea recurrence rate and time to recurrence. Moreover, screening criteria are needed to identify women who are especially susceptible to hypermenorrhea recurrence. Finally, these studies could also consider novel ablation techniques.
In summary, the combination of MEA and TCR may safely and effectively reduce the size of uterine fibroids and, thus, treat hypermenorrhea caused by submucous myomas.