Jacob Abbott
Research Mentor(s): Andriy Myronovych
Mentor Department: Surgery
Authors: Jacob Abbott, Sabrina Morrison, Andriy Myronovych
Session: Session 1 (9:00am – 9:50am)
Presentation Type: Poster 58
Abstract
Background and aims: Bariatric surgery is becoming increasingly used as a method of weight loss in morbid obesity. Weight loss correction is required in severely obese patients that are candidates for the liver transplantation. The purpose of this study was to determine whether a combined usage of vertical sleeve gastrectomy (VSG) and 70% partial hepatectomy (PH) resulted in comparable body weight and fat loss as a mouse model of VSG alone. This animal model mimics bariatric surgery and living donor liver transplant performed in a single procedure. Methods: The mice were placed on a high fat diet six weeks ahead of surgery to induce obesity, which they remained on for the remainder of the experiment. Mice were divided into four procedures: sham (N=13), VSG (N=16), PH (N=17), and VSG-PH (N=15). Body composition measurements were taken two days ahead of surgery. Half of each cohort was then sacrificed 48 hours following surgery for sample collection (liver, plasma, ileum) in order to evaluate early metabolic and regenerative response. The remaining subjects were monitored for a fifty-six day period. Blood samples were taken biweekly, along with body mass and food intake weekly. Body composition measurements were taken once again at day fifty-five after surgery. At the fifty-six day timepoint, the remaining cohorts were sacrificed and samples collected (liver, plasma, ileum, cecum). Results: VSG-PH mice exhibited sufficient survival after surgery. Pre-surgery and post-surgery fat and lean masses were consistent across all groups. Following the fifty-five day timepoint, VSG and VSG-PH mice showed significant decreases in fat mass, compared to sham and PH mice, with lean mass remaining relatively constant. Liver weight was lower among VSG and VSG-PH mice, but the liver mass-to-body ratio was consistent across groups, indicating sufficient hepatic regeneration in VSG-PH mice. This was also evidenced by the actively proliferating hepatocytes detected in the livers of VSG-PH group at 48-hour time point. Moreover, VSG-PH mice exhibited reduced baseline blood glucose levels and improved glucose tolerance compared to Sham and PH mice. Conclusions: Our results indicate that combined VSG-PH surgery is an effective procedure that results in comparable body weight and fat mass loss with VSG alone throughout the experiment. VSG-PH mice also demonstrate adequate liver regeneration equivalent to the regeneration in mice of PH group.
