The Association of Gastroesophageal Reflux Disease and Dumping Postsleeve Gastrectomy

Introduction

Globally, the increased incidence and prevalence of obesity is a major public health challenge. Obesity is associated with significant morbidity and mortality of chronic diseases, such as diabetes, hypertension, ischemic heart disease, and depression. ¹ Notably, gastroesophageal reflux disease (GERD) is highly prevalent in the obese population and has been recognized as obesity-related comorbidity. Several pathophysiological mechanisms link obesity to GERD, including increased intra-abdominal pressure, reduced esophageal clearance, increased transient relaxation of the lower esophageal sphincter (LES), and formation of hiatus hernia.^2,3 Bariatric surgery is considered the most efficient option for the treatment of obesity and resolution of comorbidities. ⁴ Laparoscopic sleeve gastrectomy (LSG) is growing at a fast rate and has gained wide acceptance as a stand-alone bariatric surgery for morbid obesity. ⁵ LSG is favored by some surgeons over Roux-en-Y gastric bypass (RYGB) because of its ease of use, fewer anatomical changes, and lower risk of nutritional complications in the long term.^6,7 Although many studies have demonstrated a positive impact of LSG on weight loss and improvement of metabolic syndrome, data on its effect on GERD are conflicting. Some studies suggest that LSG induces de novo GERD or worsens preexisting GERD, while others indicate that LSG improves GERD. Because LSG might lead to new-onset GERD or worsen an already existing GERD, some surgeons have suggested GERD as a contraindication for LSG.^8–10 Indeed, a systemic review and meta-analysis on the effect of LSG on GERD, which examined 33 studies that included GERD as either a primary or secondary outcome measure after LSG, found a slight trend toward an increased prevalence of GERD after LSG, but no definite conclusion was made due to the variety between these studies. ¹¹ Moreover, another adverse outcome of bariatric surgery is dumping syndrome, which was first recognized as a symptom complex following ingestion of food after gastric ulcer surgery. Dumping syndrome is believed to be divided into two phases: an early phase related to ingestion of hyperosmolar content leading to osmotic shift and a late phase due to reactive hypoglycemia,^12,13 and it is frequently observed after RYGB due to alteration of the upper gastrointestinal anatomy. ¹⁴ In this study, we aimed to determine the incidence of GERD and dumping syndrome in a cohort of patients who underwent LSG.

Materials and Methods

Results

Between January 2017 and June 2019, a total of 318 patients underwent LSG at the single surgeon's clinic, and of them, 155 patients participated in the questionnaire survey (44% response rate). Among the 155 patients, 7 (4.96%) met the criteria for GERD, and 24 (17.0%) met the criteria for dumping syndrome. Table 1 summarizes the demographics, GERD-HRQL score, and Sigstad score; Table 2 summarizes the incidence of GERD and dumping syndrome in the postoperative years; and Table 3 presents the factors associated with dumping syndrome. GERD was reported in six patients (5.13%) without dumping syndrome (n = 117) and in one patient (4.17%) with dumping syndrome (n = 24), and dumping patients had higher GERD scores. Table 4 presents factors associated with GERD. At the time of the survey, 31 patients took PPI, and 17 of them used it as a routine postoperative regimen for the first 6 months. Fourteen patients took PPI occasionally 6 months after LSG, but they scored less in the GERD-HRQL questionnaire.

Predictive factors for the incidence of dumping syndrome post-LSG based on multivariable analysis are presented in Table 5. The use of PPI, the difference in BMI between pre- and postoperation, and fasting during Ramadan affected the incidence of dumping syndrome.

Predictive factors for the incidence of GERD after LSG based on multivariate analysis are presented in Table 6. The only predictive factor was time from surgery, and those who had LSG for more than 2 years were more likely to score positively on the GERD-HRQL (odds ratio = 25.58 [3.24–601.42], p = 0.009].

Discussion

In this study, we investigated dumping syndrome and GERD post-LSG in a single-surgeon private practice cohort. We found an incidence of 4.96% for GERD and 17% for dumping syndrome, and the use of PPI, BMI difference, and fasting during Ramadan were associated with dumping syndrome; in addition, the time from LSG was strongly and positively correlated with GERD, and patients who reported dumping had a higher GERD HRQL score.

Several anatomical variations after sleeve gastrectomy are thought to increase the risk of GERD, including a decrease in the LES resting tone, resection of the gastric sling fibers, weakening of the phrenoesophageal and related ligaments, and dissection of the crus.^23,24 The resection of the gastric fundus causing a reduction in stomach compliance and an increase in intraluminal gastric pressure is thought to be another factor associated with increased GERD postsleeve gastrectomy. ²⁵ For example, Del Genio et al. performed high-resolution impedance manometry and analyzed combined 24-h pH and multichannel intraluminal impedance in 25 patients before and after sleeve gastrectomy; they found that the actual cause of reflux postsleeve gastrectomy was the increased intraluminal pressure, which led to stasis and bouncing back of food and acid to the esophagus, and the LES pressure remained unchanged. ²⁶ Quero et al. used magnetic resonance imaging, high-resolution manometry (HRM), and ambulatory pH-impedance measurements to assess the structure and function of the esophagogastric junction and stomach before and after sleeve gastrectomy in 35 patients; they found an increase in gastroesophageal reflux postsleeve gastrectomy, and the increased sleeve gastrectomy led to increased esophagogastric insertion angle (more obtuse) in 78% of patients, which correlated with a decrease in the resting pressure of LES as measured by HRM. They also found increased reflux in patients with more than 80% reduction in stomach capacity compared with those with 60–70% reduction, which was independent of the esophagogastric junction anatomy and physiology. Consistently, another study showed that the reduction in stomach volume correlated positively with reduced distend ability and increased luminal pressure. ²⁷ Moreover, the size of the antrum and the function of the pylorus might play a role in reflux postsleeve gastrectomy; accordingly, some surgeons resect the stomach during sleeve gastrectomy 6 cm away from the pylorus to preserve pyloric function and gastric motility. However, opponents of this technique argue that it might lead to inadequate weight loss after SG. ²⁸

Himpens et al. found that reflux increased 1 year after LSG but then decreased with time in 40 patients, ²⁵ probably due to abnormal gastric emptying in the first year postsleeve gastrectomy, which resolved with time, thus leading to improved GERD. However, in our study, we found a higher incidence of GERD postsleeve gastrectomy, probably due to lack of compliance with follow-up, especially in nutritionists, because dietary habits are important to avoid GERD. In addition, changes in BMI, including weight regain, were not associated with an increased risk of reflux in our cohort, although one would think that weight regains postsleeve gastrectomy could increase the risk of reflux with the passage of more time postsleeve gastrectomy. The shape of the sleeve could also contribute to the risk of reflux because patients with a lower pouch on the upper GI series will have less chance of reflux compared with those with a tubular shape or an upper pouch. ²⁹

Dumping syndrome is thought to result from the sudden presence of gastric content in the proximal small bowel, thereby leading to a set of vasomotor and gastrointestinal symptoms. The relationship between dumping syndrome and gastric resections and bypasses is well established. We reported a dumping incidence of 17% in our cohort. Patients with dumping syndrome had a higher GERD score, but only seven patients scored positive for GERD-HRQL. Moreover, fasting during Ramadan, BMI difference, and PPI use were associated with dumping syndrome in our cohort. Dumping syndrome occurred more during Ramadan because patients fasted from food and water for a long duration. Eating and drinking after a long duration of fasting increase the incidence of dumping syndrome, as shown in this cohort.

The association between GERD and dumping in our study could be explained by dietary habits. Patients who do not adhere to dietary modifications after sleeve gastrectomy can be at an increased risk of dumping and reflux; for example, not separating solids and liquids during meals, not limiting caffeine and sugar intake, and having larger meals instead of frequent smaller meals can increase the risk of both dumping and reflux. ²² In addition, sleeve gastrectomy affects gastric emptying because fundectomy, resection of the greater curvature, and resection along one part of the gastric body influence the gastric pacemaker area, and resection of the antrum impacts the function of the antral pump. ²⁶

One limitation of this study was the low response rate of 44% and the short follow-up duration following surgery. Perhaps most patients that responded were those that had ongoing problems or perhaps only those that really felt dedicated to our program and thus gave a more favorable review of their symptoms. In addition, endoscopy and PH studies were not performed in our study, although GERD can be graded more objectively by endoscopy and PH studies. However, few studies have examined the incidence of both dumping and GERD in LSG patients, despite the established link between LSG, GERD and dumping; therefore, further studies are warranted to determine both dumping and GERD in LSG patients to delineate the underlying mechanisms and factors that increase GERD post-LSG.

Conclusion

The incidence of GERD and dumping postsleeve gastrectomy are variable and a relationship between the two may exist. Further studies are needed to examine the relationship between dumping and GERD after LSG.