Bariatric Arterial Embolization with Non-spherical Polyvinyl Alcohol Particles for Ghrelin Suppression in a Swine Model.

Abstract

To evaluate the effect of bariatric arterial embolization (BAE) with non-spherical polyvinyl alcohol (PVA) particles on systemic ghrelin levels, weight change, and gastric ulceration risk in a swine model. From March 2014 to February 2015, ten healthy swine were used in the study (mean weight 31.5kg; range 24.0-41.5kg). The animals were randomly assigned to two groups: the embolized group (n=5) in which BAE was performed and the control group (n=5). In the embolized group, BAE was performed by selectively infusing 150-250 or 50-150μm PVA into the gastric arteries that supplied the fundus of the stomach. In the control group, a sham procedure was performed with saline infusion. Plasma ghrelin levels were prospectively obtained at baseline and every 2weeks thereafter. Endoscopy was performed 3weeks after BAE to see whether any gastric ulcer occurred. To determine the durability of the occluded arteries, repeated celiac trunk angiography was performed 8weeks after BAE. Then, all the swine were killed and necropsies were performed. The mean post-procedure ghrelin value decreased by 370.0pg/mL in the embolized group at week3 (mean 536.0±334.3pg/mL) and week5 (mean 515.0±150.0pg/mL, p<0.05) relative to baseline (880.0±559.5pg/mL), respectively, but ghrelin levels were not significantly decreased between the embolized and control groups. There was a significant body weight change as follows: 35.1±9.5 to 46.6±15.7kg and 31.8±5.8 to 41.2±6.6kg at baseline and endpoint in the control and embolized groups, respectively (p<0.05). However, the difference between groups was not significant at endpoint. In the embolized group, ulcerations were identified in three animals (60%) and the recanalization of the embolized arteries was noted on follow-up angiography in three animals (60%), respectively. BAE with PVA particles can transiently suppress ghrelin levels in embolized animals, but levels are not significantly different compared to controls. Stomach ulcerations were identified in 60% of the embolized animals.