Uterine artery embolization for symptomatic adenomyosis: A new technical development of the 1-2-3 protocol and predictive factors of MR imaging affecting outcomes

Purpose: To evaluate the safety and effectiveness of a new embolization technique named the 1-2-3 protocol to achieve complete necrosis of adenomyosis after uterine artery embolization (UAE) and to determine predictive factors on magnetic resonance (MR) imaging. Materials and Methods: A total of 40 patients with adenomyosis without leiomyomas diagnosed on MR imaging were prospectively enrolled. They were subdivided into three categories based on MR signal intensity (SI) of the adenomyosis on T2-weighted imaging: dark, low, and heterogeneous SI or SI equal to that of the myometrium. Nonspherical polyvinyl alcohol particles were used in all cases, beginning with 150-250-μm particles and progressively increasing to 250-355-μm and then 355-500-μm particles to the endpoint. Patients were assessed for extent of devascularization on MR imaging and for durability of symptom control. Results: Of the 40 patients who underwent UAE for adenomyosis with the 1-2-3 protocol, 33 (82.5%) exhibited complete necrosis of adenomyosis. All six patients with dark SI of adenomyosis exhibited complete necrosis (100%). Of the 28 patients with low SI of adenomyosis, 25 (89.3%) showed complete necrosis. Among the six patients with heterogenous SI or SI equal to that of myometrium, only two (33.3%) showed complete necrosis (P < .01). Of 16 patients with complete necrosis followed up to 18 months, none reported recurrent menorrhagia. Of the five patients without necrosis, only one had no symptoms at 18 months. Conclusions: UAE with the 1-2-3 protocol is safe and highly effective to achieve complete necrosis of adenomyosis. Dark SI of adenomyosis is the most favorable predictive factor for UAE on MR imaging, followed by low SI. Heterogenous SI or SI equal to that of the myometrium is an unfavorable predictive factor.