Subtypes of adenomyosis assessed by MRI is useful to weigh the relative difficulty of laparoscopic hysterectomy

Objective: To evaluate the relative difficulty of laparoscopic hysterectomy (LH) for adenomyosis by categorizing them into four subtypes.Methods: We retrospectively collected 56 cases of adenomyosis treated by laparoscopy at our hospital from January 2007 to December 2012. After subcategorizing them into four subtypes on the basis of MRI geography (subtype 1: intrinsic subtype, subtype 2: extrinsic subtype, subtype 3: intramural subtype, subtype 4: indeterminate subtype), we statistically analyzed the surgical results including operation time, blood loss during operation and conversion rate to open surgery using Mann-Whitney U test.Results: The operation time for subtype 1 adenomyosis was shorter than that for subtype 2 adenomyosis (147 vs. 215 min, p<0.005). Compared to subtype 2/3, subtype 1 had small amount of blood loss during operation (260 vs 60/ 230 ml, respectively, p<0.05). Compared to subtype 2/ 3/ 4, subtype 1 has small proportion of conversion to open surgery (0 vs 25/ 20/ 10.3 %, respectively,), which was not statistically significant. We further revealed that revised American Society for Reproductive Medicine (rASRM) score of subtype 2 patients was higher than those of subtype 1/3 patients (60 vs 2/ 2 points, respectively, p<0.005, p<0.01). Conclusions: Categorization of adenomyosis based on MRI finding was considered to be an efficient method because of the increased amount of blood loss and elevated rASRM score of subtype 2 adenomyosis. Therefore, subtype 2 was considered to be the most difficult entity of adenomyosis in LH. Although the difficulty of LH for subtype 4 adenomyosis should be further investigated, our analysis implied the importance to categorize adenomyosis by MRI, and this method can be useful for evaluating the difficulty of LH.