Bariatric Arterial Embolization with Calibrated Radiopaque Microspheres and an Antireflux Catheter Suppresses Weight Gain and Appetite-Stimulating Hormones in Swine

Purpose: To examine safety and efficacy of bariatric arterial embolization (BAE) with x-ray–visible embolic microspheres (XEMs) and an antireflux catheter in swine. Material and Methods: BAE with selective infusion of XEMs (n = 6) or saline (n = 4, control) into gastric fundal arteries was performed under x-ray guidance. Weight and plasma hormone levels were measured at baseline and weekly for 4 weeks after embolization. Cone-beam CT images were acquired immediately after embolization and weekly for 4 weeks. Hormone-expressing cells in the stomach were assessed by immunohistochemical staining. Results: BAE pigs lost weight 1 week after embolization followed by significantly impaired weight gain relative to control animals (14.3% vs 20.9% at 4 weeks, P =.03). Plasma ghrelin levels were significantly lower in BAE pigs than in control animals (1,221.6 pg/mL vs 1,706.2 pg/mL at 4 weeks, P <.01). XEMs were visible on x-ray and cone-beam CT during embolization, and radiopacity persisted over 4 weeks (165.5 HU at week 1 vs 158.5 HU at week 4, P =.9). Superficial mucosal ulcerations were noted in 1 of 6 BAE animals. Ghrelin-expressing cell counts were significantly lower in the gastric fundus (17.7 vs 36.8, P <.00001) and antrum (24.2 vs 46.3, P <.0001) of BAE pigs compared with control animals. Gastrin-expressing cell counts were markedly reduced in BAE pigs relative to control animals (98.5 vs 127.0, P <.02). Trichrome staining demonstrated significantly more fibrosis in BAE animals compared with control animals (13.8% vs 8.7%, P <.0001). Conclusions: XEMs enabled direct visualization of embolic material during and after embolization. BAE with XEMs and antireflux microcatheters was safe and effective.