Predicting the Fibroid-Migratory Impact of UAE: Role of Pre-embolization MRI Characteristics

To investigate potential factors on MR imaging that could be used to predict migration of uterine fibroids post-UAE.

We retrospectively reviewed patients referred for UAE having pre-procedural and 6 months post-procedural MRI, at a tertiary centre, over a 1-year period. Pre- and post-UAE images were reviewed in 64 women by two radiologists to identify the sub-type, dimensions, and infarction rate of each dominant fibroid. The shortest distance between the fibroid and the endometrial wall was measured to determine intramural fibroid movement. Paired sample T tests and two-sample T tests were used to compare between pre- and post-embolization variations and between migrated and non-migrated intramural fibroids, respectively. After preliminary results suggested potential predictors of intramural fibroids migration, we tested our findings against the non-dominant intramural fibroids in the same patients.

Review of images revealed 35 dominant intramural fibroids, of which eight migrated to become submucosal fibroids, while five were either partially or completely expelled. These 13 migrated fibroids had a shorter pre-procedural minimum endometrial distance (range 1-2.4 mm) and greater maximum fibroid diameter (range 5.1-18.1 cm), when compared to non-migrating fibroids. On image reassessment, the migrated non-dominant intramural fibroids had a minimum endometrial distance and maximum fibroid diameter within the same range.

Intramural fibroids with a minimum endometrial distance less than 2.4 mm and a maximum fibroid diameter greater than 5.1 cm have a high likelihood of migrating towards the endometrial cavity after UAE.