The association between GERD and obesity has generated great interest, because obesity has been indicated as a potential risk factor for reflux disease. A directly dependent relationship has been reported because an increase in body mass index has mirrored an increase in the risk of GERD. The incidence of reflux in the obese population has been cited as high as 61%. The pathophysiologic mechanism underlying the link between obesity and GERD has not been fully elucidated and seems to be multifaceted. As the number of obese patients is increasing, so is the volume and variety of bariatric procedures. The effect of bariatric surgery on preexisting GERD or newly developed GERD differs by procedure.
GERD AFTER ROUX-EN-Y GASTRIC BYPASS
Roux-en-Y gastric bypass (RYGB) has been used as a standalone reflux procedure. Mechanisms of the antireflux effect of RYGB include diverting bile from the Roux limb, promoting weight loss, lowering acid production in the gastric pouch, rapid pouch emptying, and decreasing abdominal pressure over the LES. Several studies have examined the relationship between GERD and RYGB. Studies have also analyzed symptomatic relief by using questionnaires before and after the procedure. One study has examined further the incidence of esophagitis postoperatively on endoscopy. Merrouche and colleagues showed a 6% incidence of esophagitis on endoscopy after RYGB; however, the preoperative incidence was not mentioned.
Pallati and colleagues also examined the GERD symptoms after several bariatric procedures by using the Bariatric Outcomes Longitudinal Database. GERD score improvement was highest in the RYGB group; 56.5% of patients showed improvement of symptoms. The study concluded that RYGB was superior to all other procedures in improving GERD. The proposed but unproven mechanisms included a greater weight loss and a decrease in the amount of gastric juice in the proximal pouch. The study, however, did not show any objective measures of GERD improvement. Another study by Frezza and colleagues showed a significant decrease in GERD-related symptoms over the 3-year study after laparoscopic RYGB, with decrease in reported heartburn from 87% to 22% (P<.001). The authors proposed that, in addition to volume reduction and rapid egress, the mechanism of how this procedure affects symptoms of GERD is through weight loss and elimination of acid production in the gastric pouch. The gastric pouch lacks parietal cells; thus, there is minimal to no acid production and also, owing to its small size, it minimizes any reservoir capacity to promote regurgitation.
Varban and colleagues examined the utilization of acid-reducing medications (proton pump inhibitor and H2-blockers) at 1 year after various bariatric procedures. The groups reported that at 1 year after RYGB, 56.2% of patients would discontinue an acid-reducing medication that they had been using at baseline. Interestingly, the group also showed that 19.2% of patients would also start a new acid-reducing medication after RYGB. Given the number of studies that have reported improvement in GERD symptoms after RYGB, this procedure is now widely accepted as the procedure of choice for treatment of GERD in the morbidly obese patient. Although no increased risk is conferred to patients with a body mass index of 35 kg/m2 or higher who undergo fundoplication for GERD the recommendation and practice of many surgeons is to perform a laparoscopic gastric bypass in lieu of fundoplication owing to its favorable effect on other comorbid conditions. In addition, advocates of the RYGB are promoting a conversion to an RYGB instead of a redo fundoplication.
In a recent study, Stefanidis and colleagues followed 25 patients who had previous failed fundoplication, which was taken down and converted to an RYGB. Patients were followed with the Gastrointestinal Quality of Life Index and the Gastrointestinal Symptoms Rating Sale. The revision surgery led to resolution of GERD symptoms for a majority of the patients. The authors concluded that an RYGB after a failed fundoplication has excellent symptomatic control of symptoms and excellent quality of life. However, owing to the technical challenges of the procedure and the potential for high morbidity, it should only be performed by experienced surgeons.
GERD AFTER SLEEVE GASTRECTOMY
Sleeve gastrectomy (SG), which was originally described as a first stage of the biliopancreatic diversion, is a relatively new treatment alternative for morbid obesity. It has become popular owing to its technical simplicity and its proven weight loss outcomes. Although it has many positive effects on obesity and obesity-related comorbidities, the association between GERD and SG remains controversial. Although some studies have reported improvement in GERD symptoms after SG, the majority of studies have reported an increase in GERD symptoms. The International Sleeve Gastrectomy Expert Panel reported a postoperative rate of GERD symptoms after SG in up to 31%; however, others cited increased GERD prevalence after surgery between 2.1% and 34.9%.
Studies Showing an INCREASE: Several studies have shown an increase of GERD after SG at various time points. The comparison between different studies is difficult owing to variations in the definition of GERD. Although some have utilized the use of proton pump inhibitors as a diagnostic tool, others have used the definition of typical heartburn and/or acid regurgitation occurring at least once per week. Few studies used objective data to define reflux.
Tai and colleagues examined symptoms of GERD and erosive esophagitis at 1 year after laparoscopic sleeve gastrectomy (LSG). The groups concluded that there was a significant increase in the prevalence of GERD symptoms and erosive esophagitis (P<.001), in addition to a significant increase in the prevalence of hiatal hernias (P<.001), which was higher in patients who presented with erosive esophagitis after LSG. Others have shown a similar increase of GERD at 1 year. Himpens and colleagues compared adjustable gastric banding (AGB) and SG at 1 and 3 years after procedures. GERD seemed de novo after 1 year in 8.8% and 21.8% of patients with AGB and SG, respectively. At 3 years, however, rates changed to 20.5% and 3.1% in the ABG and SG groups. Another study followed patients for more than 6 years and reported 23% to 26% of patients reporting frequent episodes of GERD. Various mechanisms have been postulated to cause symptoms of GERD after LSG. As SG alters the gastroesophageal anatomy, it has been hypothesized that the anatomic abnormalities created contribute to the development of GERD in patients.
Lazoura and colleagues showed that the final shape of the sleeve can influence the development of GERD. The group showed that patients with tubular pattern and inferior pouch (preservation of the antrum) did better in terms of regurgitation and vomiting compared with a tubular sleeve with a superior pouch. Others have also suggested the importance of antral preservation to avoid GERD development. An increase in acid production capacity can cause reflux in the case of an overly dilated sleeve, whereas impaired esophageal acid clearance can lead to reflux in a smaller sleeve. Formation of a neofundus can in an effort to avoid fistulas may also lead to development of GERD. Daes and colleagues further concentrated on describing and standardizing the procedure to reduce GERD symptoms. The authors identified 4 technical errors that led to development of GERD after the procedure: relative narrowing at the junction of the vertical and horizontal parts of the sleeve, dilation of the fundus, twisting of the sleeve, and persistence of hiatal hernia or a patulous cardia. By ensuring careful attention to surgical technique and performing a concomitant hiatal hernia repair in all patients, they reduced the rate of postoperative GERD to only 1.5%. The group concluded that hiatal hernia is the most important predisposing factor.
Studies Showing REDUCTION: Several studies have reported either decreased or no association between GERD and LSG. Interestingly, in some of these studies, GERD improvement has been reported as a secondary outcome. Rawlins and colleagues reported an improvement of symptoms in 53% of patients, but de novo GERD in 16% of patients. A multicenter prospective database review examined GERD in all 3 major bariatric procedures and reported improvement in all. The authors used medication use to define GERD. A small portion of patients reported worsening GERD, which was highest in the SG group. Sharma and colleagues also reported an improvement of GERD as assessed by symptom questionnaires, as well as improvement in grade of esophagitis on endoscopy. The possible mechanisms for improvement of GERD postoperatively are faster gastric emptying, reduction in gastric reservoir function, gastrointestinal hormonal modifications, decrease in acid secretions, and decrease in weight. Daes and colleagues reported a decrease in incidence of GERD by using a standardized operative technique and concomitant repair of hiatal hernia.
Owing to conflicting reports about the association between GERD and LSG, this procedure is controversial in patients with preexisting GERD. If LSG is considered in this population, hiatal hernia repair and meticulous technique are essential. We would like to emphasize the importance of preoperative testing to define the anatomy and evaluate preexisting GERD, esophagitis, Barrett’s esophagus, or the presence of hiatal hernia.