Physiology and Pathophysiology of Gastro-Oesophageal Reflux in Patients with Adjustable Gastric Bands
Creators: name: Yao-Yen Richard Chen
Publisher: name: Monash University
Year: 2017
Subjects: Uncategorized

description: Obesity is epidemic in the developed world. 62.8% of adult Australian populations were overweight or obese in 2012. Obesity is a recognised risk factor for gastro-oesophageal reflux disease (GORD). Fundoplication is the standard of care for medical refractory GORD. However, the efficacy and longevity of fundoplication in the obese patient group have been a topic of ongoing debate. Regardless of success in GORD control, fundoplication does not address co-morbidities associated with morbid obesity such as diabetes, cardiovascular disease and cancer. It is possible that rather than considering purely anti-reflux procedures for obese persons with GORD, they would be better served by a procedure that provided not only reflux control but weight loss, with associated health benefits. <br> <br> Laparoscopic Adjustable Gastric Band (LAGB), Roux-en-Y Gastric Bypass (RYGB) and Laparoscopic Sleeve Gastrectomy (LSG) are commonly performed bariatric procedures nowadays whereas Biliopancreatic Diversion (BPD) with or without Duodenal Switch (DS) and Vertical Banded Gastroplasty (VBG) are being performed in lesser frequency. There is conflicting opinion and evidence regarding the effects of LAGB and LSG on GORD in the literature. Currently there is no published systematic review on the effects of all commonly performed bariatric procedures on GORD. <br> <br> The aims of this Masters project were to review the current literature on the topic of the management of GORD in obese patients by conducting a systematic review, to describe the physiology of reflux in LAGB patients by designing an apparatus capable of measuring oesophageal manometry and pH simultaneously, to describe the anatomical and histological findings in LAGB patients with or without gastro-oesophageal reflux by performing barium swallow and gastroscopy and biopsy; and to pilot these novel techniques in a small number of patients who were weight stable following LAGB so as to validate their use in a larger clinical trial. <br> <br> We hypothesized that LAGB patients with reflux symptoms have abnormally large pouches above LAGB containing a large number of parietal cells leading to higher 24-hour acid exposure whereas in asymptomatic LAGB patients, there should only be small pouches above LAGB with minimal or no parietal cells in these pouches with normal 24-hour oesophageal acid exposure. <br> <br> The systematic review showed that weight loss results from LAGB, LSG, RYGB and VBG were comparable and satisfactory at least in short term. With regards to the effects of bariatric procedures on GORD, there was conflicting evidence for LAGB and insufficient evidence for LSG. RYGB was shown to have anti-reflux property. VBG had minimal effects on GORD. Further studies are required to investigate the effects of LAGB and LSG on GORD. <br> <br> We have designed an apparatus capable of concurrent measurement of pH and high-resolution manometry with real-time display. This is a novel technique we have now tested, validated its use in our pilot subjects and supported our hypotheses. <br> <br> We plan to use these data to inform a clinical trial involving both LAGB and LSG patients that is sufficiently powered to study the physiology and pathophysiology of GORD in this cohort of patients.