3:09 PM Abstract No. 4 ■ FEATURED ABSTRACT Arterial embolization of the shoulder for pain secondary to adhesive capsulitis: interim results from an investigational device exemption US trial

Abstract

Adhesive capsulitis (AC) has been postulated to cause pain secondary to capsular neovascularization and accompanying nerve growth. Results from an initial overseas study of arterial embolization with an antibiotic were promising. We present our interim results from a prospective US Investigational Device Exemption pilot study evaluating arterial embolization of the shoulder (AES) with spherical embolic. Sixteen patients (14F, 2M: Mean age 52y) with adhesive capsulitis resistance to at least 30 days of conservative treatment were enrolled (NCT03676829). Included subjects had a visual analog scale (VAS) greater than 40 mm, and did not have prior shoulder replacement surgery, autoimmune disease, or complete rotator cuff tear All subjects were assessed before and after the procedure with MRI, VAS (0-100 mm), Single Assessment Numeric Evaluation (SANE, 0-100), and American Shoulder and Elbow Surgeons (ASES, 0-100) scores. Upper extremity angiography was performed in all subjects via radial artery access and six target arteries were selected when present. Embolization was performed with spherical embolic when hypervascularity was noted. Adverse Events (AE) were recorded at all follow-up time points. Neovascularity was identified in all patients by arteriography and AES was technically successful in all patients (16/16). A total of 64 arteries were embolized with 75-micron embolic. Baseline VAS, SANE, and ASES scores before the procedure for all 16 patients were 87.5 mm, 30.8, and 28.8 respectively. Eleven patients were eligible for 1-month follow-up at present and demonstrated significant improvement in VAS (pre/post mean = 89/32, P = 0.00003), SANE (pre/post mean = 32/60, P = 0.02), and ASES (pre/post mean= 29/59, P = 0.004). At 3 months, mean VAS was 13.3, SANE 82.9, and ASES 79.3. No major adverse events occurred. Transient skin discoloration around the treatment region was reported in 9 patients with complete resolution at 1-month follow-up. Interim results demonstrate that AES is an effective treatment for patients with AC refractory to conservative treatment.