IBC-Oxford University2023_BJSOral_1Dynamic Magnetic Resonance Imaging (Dy-MRI) Evaluation of the Impact of Endoscopic Sleeve Gastroplasty (ESG) on Gastric Structure and Function in Morbid Obese Patients

Abstract

Abstract Introduction Endoscopic sleeve gastroplasty (ESG) is a restrictive endoluminal bariatric procedure consisting in the application of multiple full-thickness sutures to reduce gastric capacity (GC) and slow down gastric emptying (GE). Although results are promising, a large variation in the weight loss outcomes is reported. Dynamic resonance imaging (Dy-MRI) has been successfully applied for the assessment and analysis of gastrointestinal (GI) function. It permits to acquire large field-of-view, dynamic, high- resolution, three-dimensional (3D) image data with excellent soft-tissue contrast in less than a second3. In addition, our group previously demonstrated a significant correlation between weight loss and gastric anatomy changes assessed by Dy-MRI in laparoscopic sleeve gastrectomy (LSG) patients. The aim of this study is to use Dy-MRI to objectively assess gastric structural and functional changes 6 months after ESG and their impact on weight loss. Material and methods Prospective single centre study. Patients underwent preoperative and postoperative (after 6 months) Dy-MRI to evaluate total GC and GE changes, immediately after the ingestion of 400 ml of liquid meal and over time up to 120 minutes after ingestion (T120). Only patients with a complete follow up at and 6 months (M6) were included. Demographic data, pre- and intra-operative data, and weight loss outcomes were collected. Continuous variables were reported as median and interquartile rank (IQR), while categorical variables as numbers and percentages. Results From July 2021 to June 2023, 16 ESG patients participated in this study. Patients had a median age of 41.5 years (IQR:35-49.7) with a median BMI (kg/m2) of 36.9 (IQR: 34.08-42.18). A median number of 6 (IQR: 5.2-6) purse string sutures were placed during the ESG. There were no complications. At the follow-up gastroscopy at M6 all patients presented an intact ESG with all the suture still present. Dy- MRI showed a median GC reduction of 34.1% of the initial volume (p<0.0001) and GE decreased by 0.43 mL/min (p=0.01). As a whole, the study population had a 16.8% of total weight loss (TWL) at M6 (p<0.0001). Similarly, the median BMI decreased from 36.9 to 29.9 (p=0.01). %TWL varied from 15.5 at M3 to 18.3 at M6. During the same time-elapse, %EWL increased from 46.4 to 57.1. Discussion and Conclusion Dy- MRI is confirmed to be a non-invasive method capable of objectively quantify gastric volume reduction and GE changes after ESG. It is likely that these two factors play a synergic role in the weight loss journey of patients undergoing ESG. Further investigations in a larger sample are needed to support these initial findings and to support an evidence based, patient specific approach to endoscopic gastric remodelling.