To evaluate the long-term incidence and effects of gastroesophageal reflux disease in the Chinese population after laparoscopic sleeve gastrectomy.

Laparoscopic sleeve gastrectomy (SG) has gained popularity as a primary bariatric procedure in the past decade. According to the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO), 43.6% of all bariatric procedures performed worldwide were SG between 2013 and 2017. Long term data of SG have shown that the procedure is able to achieve adequate weight loss and metabolic outcomes compared with other bariatric procedures. Furthermore, it has gained popularity due to its relatively simpler procedure, shorter operative time, avoidance of intestinal anatomy rearrangement, anastomosis, risk of internal hernia, and lower risk of malnutrition.

One major drawback to SG is potential development of gastrointestinal reflux disease (GERD). According to the Montreal Classification, GERD is defined as heartburn and regurgitation because of reflux contents of the stomach into the esophagus, causing symptoms that interferes with physical activity, disturbs sleep and reduce productivity at work . It has been shown to significant impact on patients' post-operative quality of life negatively . Currently there are discrepancy in the medical literature, while some studies found worsening of GERD or development of GERD (de novo GERD) after SG, some found improvement of GERD post-operatively. From a recent meta-analysis by Yeung et al comprising 10, 718 patients with follow-up period from 3 to 132 months, 19% of patients experienced worsening of GERD while 23% developed de novo GERD after SG.

Furthermore, long term complications of GERD include the development of erosive esophagitis, Barret's esophagus and even esophageal adenocarcinoma. From the same meta-analysis, the long-term prevalence (>24 months) of erosive esophagitis and Barret's esophagus were 28% and 8% respectively. There have also been isolated case reports of development of esophageal adenocarcinoma after SG. From the investigators' literature review, four cases were reported. Two of the cases had no pre-operative endoscopy, one case had pre-operative diagnosis of Barret's esophagus. The other case developed esophageal adenocarcinoma despite normal pre-operative endoscopy 5 years after SG.

The epidemiology of GERD is different in Western countries and in Asian countries. Although the incidence of GERD has increased in the past decades, the prevalence of GERD was 5.2-8.5% base on symptoms. Prevalence of Barret's esophagus remained rare at 0.06-0.85%. In patents who have received SG, Tai et al showed that the prevalence of GERD increased from 12.1 to 47% based on Reflux Disease Questionnaire at one year after SG. The prevalence of erosive esophagitis also increased from 16.7 to 66.7%. based on upper gastrointestinal endoscopy findings at one year. In the long run, the prevalence of de novo GERD was 17-45% based on symptoms and proton pump inhibitors use from the case series by Pok et al. and Chang et al. with a follow-up period up to 7 years and 10 years respectively.

From the current Asian literature, data on long term incidence of GERD after SG based on objective assessment tools and endoscopy findings was lacking. There is also no adequate data on the long-term occurrence of erosive esophagitis and Barret's esophagus after SG, which would have important significance in pre-operative counselling.

The objective of the study is to evaluate the long-term incidence and effects of gastroesophageal reflux disease in the Chinese population after laparoscopic sleeve gastrectomy.

Inclusion Criteria:

• Chinese patients who received laparoscopic sleeve gastrectomy at Prince of Wales Hospital, The Chinese University of Hong Kong
• SG has been performed more than 36 months
• Patient received preoperative OGD and GI symptom assessment with C-GIQLI questionnaire
• Willing and able to consent to the study

Exclusion Criteria:

• Revisional surgery
• Concomitant surgeries (except hiatal repair/ cholecystectomy)
• Mentally incompetent patients or patients less than 18 years old
• Pregnant patients
• Inmates
• Unable/unwilling to consent to the study
• Unable/unwilling to undergo follow-up assessments

Chinese patients who received laparoscopic sleeve gastrectomy at Prince of Wales Hospital, The Chinese University of Hong Kong for more than 36 months