Ultrasound-guided microwave ablation for symptomatic abdominal wall endometriosis and treatment response evaluation with contrast-enhanced imaging: The first experience.

Introduction: Abdominal wall endometriosis (AWE) is a relatively uncommon condition associated with diagnostic and therapeutic difficulties among all the extra pelvic endometriosis. The main therapies include surgery and oral contraceptive administration. Percutaneous cryoablation and high intensity focused ultrasound (HIFU) are also proven to be valid alternatives. Microwave ablation (MWA) as one of the thermal ablation methods has not been applied in the treatment of AWE yet. Herein the feasibility of ultrasound (US) -guided MWA for AWE was explored and treatment response evaluation was carried out using contrast-enhanced imaging.

Methods: Three consecutive patients who underwent US-guided MWA for AWE with typical symptoms were included in this retrospective study. US, magnetic resonance imaging (MRI), laboratory tests, and US-guided core-needle biopsy were conducted for pre-treatment assessment and ruling out malignancy. The interventional procedure was carried out under local anesthesia with MWA and the output power was 60w. Post-treatment contrast-enhanced ultrasound (CEUS) was performed to evaluate the instant treatment response. The follow-up intervals were 1 month, 6 months, and 12 months after treatment. The clinical symptoms and condition of AWE lesions were recorded in each follow-up.

Results: The MWA procedure was completed in all the patients with no blood perfusion inside each lesion by instant CEUS after treatment. The mean ablation time was 687 seconds (s) for a single patient (ranged from 660s to 742s). Clinical symptoms were relieved evidently at the end of the follow-up. The pain according to the visual analogue scale (VAS) decreased from 4-6 before treatment to 0-2 after treatment. Mild to moderate complications included slightly abdominal pain and fat liquefaction occurred. In terms of technical outcomes, the volume of all six lesions reduced in different degrees at the end of follow-up (ranged: 16.6% to 100%).

Conclusion: US-guided MWA may be a feasible and promising approach for symptomatic AWE.