Bariatric Surgery and the Mechanisms of Gastroesophageal Reflux Disease

Introduction

The association between obesity and gastroesophageal reflux disease (GERD) is very well known. Obese patients have 2–2.5 more chances to develop reflux symptoms in comparison with the general population.^1,2 GERD is present in >50% of obese patients and up to 70% among morbidly obese patients who seek bariatric surgery.^3,4

The pathophysiology of GERD is not completely understood but is likely to have a multifactorial nature. Obesity, one of the main factors, is reported to increase the intragastric pressure with impaired gastric emptying, the frequency of transient lower esophageal sphyncter (LES) relaxation episode and the gastroesophageal pressure gradient, potentially leading to GERD. The findings of manometric studies, however, have been inconsistent, indicating both decreased and normal lower esophageal sphincter pressures in obese patients. Studies have also suggested that rather than obesity, the amount and the type of dietary intake, notably fat, associated to hormonal changes (e.g., cholecystokinin, ghrelin) are responsible of GERD.^1,5

Surgery is the only effective treatment for morbid obesity and obtains the best long-term outcomes. Each bariatric procedure (restrictive or malabsorptive) is associated with a different balance of risks and benefits, in terms of surgical complications, excess weight loss (EWL), and resolution of GERD. Since specific procedure guidelines are missing, surgical treatment for morbid obese patients must be selected according to the clinical characteristics of the patient, his eating habits and patient willingness. It should be based on a preoperative workup with shared decision making, with the double purpose of treating both GERD and obesity. ⁶ The effect of bariatric surgery on pre-existing GERD, or newly developed GERD, is still controversial and measuring GERD is a difficult task. Chan et al. ⁷ showed the difficulty between self-reported reflux symptoms and their correlation with objectified reflux: out of 336 patients who completed a GERD questionnaire, only half of the patients who claimed to have GERD were confirmed positively by tests such as the 24 hours pH-metry. Some studies evaluate GERD on the evolution of the patient's prescriptions of proton pump inhibitors (PPIs) or antacids. This measure is not always representative since some patients have GERD but are untreated, and others are not symptomatic of GERD but consume PPIs systematically as a preventive or by habitude.

Although bariatric surgery has been successfully performed for several decades, the mechanism of action of each type of procedure is not completely understood both for the weight loss, GERD remission or de novo GERD. The current editorial summarizes the principal mechanisms involved in GERD for different bariatric procedures.

Laparoscopic Adjustable Gastric Banding

After the initial description of laparoscopic adjustable gastric band in 1993, it soon acquired popularity among patients and surgeons, which led at the beginning of 2000, together with the rising prevalence of morbid obesity, to a yearly increase in the number of band implantations. The laparoscopic adjustable gastric banding (LAGB) was implanted with low morbidity and mortality. On average, good EWL is achieved as well as a decrease in comorbidities in the short term. The skepticism among some bariatric surgeons about the long-term weight loss results, complications rates, and patient satisfaction have been confirmed by many bariatric centers. For some years now, there has been a decline in the number of LAGB procedures in both Europe and, later, in the United States. In the majority of the national registers the numbers of gastric band removal and revisions after LAGB have surpassed the implants between 2010 and 2015. ⁸

LAGB is reported to briefly delay semisolid transit of food into the distal stomach. This obstruction to flow allows content to remain in the stomach section above the band and below the LES, favoring gastroesophageal reflux if the gastric pouch fills rapidly. ⁹ In contrast, some cases of suppression of preoperative GERD after LAGB were described. It is currently unclear if GERD resolution depends on the weight loss. The possible theoretical antireflux mechanism of LAGB appear when the band is placed and fixed correctly, as high as possible and a very small pouch is constructed. Still, it seems to be a higher incidence of large pouches with time, leading to increasing symptoms and findings of GERD. LAGB could reduce the gastroesophageal reflux in the short term in some cases, but overeating will inevitably lead to enlargement of the pouch with loss of its antireflux properties. ¹⁰

Roux-en-Y Gastric Bypass Laparoscopic Roux-en-Y Gastric Bypass

Laparoscopic Roux-en-Y gastric bypass (LRYGB) was considered the gold standard for both treatment of obesity and GERD and it consists in creating a small gastric pouch connected to the alimentary limb. For long time, many authors have considered that the alimentary limb should be longer than the biliary one. With weight recidivism after LRYGB, many centers have advocated longer biliary loops. LRYGB has a higher complication rate (marginal ulcers, internal hernia) compared with laparoscopic sleeve gastrectomy (LSG) but improved results on GERD. Its mechanisms of diverting the bile away from the esophagus, decreasing acid production in the gastric pouch, and reducing volume of acid reflux is well known. For morbid obese patients with refractory reflux disease and/or Barrett's esophagus (BE) after LSG, LRYGB has been suggested by many reports as an excellent antireflux procedure, proven by the disappearance of symptoms and the healing of endoscopic esophagitis or peptic ulcer in all patients, and important regression of intestinal metaplasia to cardiac mucosa. Still, there are some cases with recurrence of reflux after LRYGB explained probably by neglected hiatal hernia, large gastric pouch, or multiple revisional procedures.

Although the LRYGB was considered the gold standard procedure for obese patients with reflux disease, >35% of patients who underwent LRYGB had at least one complication within the 10-year follow-up period. ¹¹ In another study, Sandler and collegues ¹² reported on 129,432 LRYGB patients amounting to an overall mortality rate at 1, 5, and 10 years of 2.2%, 4.4%, and 8.1%, respectively. The number of patients hesitating or refusing the choice for LRYGB because of long-term complications cannot be neglected.

One Anastomosis Gastric Bypass

One anastomosis gastric bypass (OAGB) has been promoted as a quick and effective alternative to the standard LRYGB procedure. In some reports, it seems more efficient on weight loss (70%–80% at 2 years) and comorbidities with immediate improvement of diabetes. ¹³ It consists of a unique gastrojejunal anastomosis between a gastric pouch and a jejunal loop of 150–200 cm. It also has the advantage of being less technically difficult (only one anastomosis and no closure of peritoneal spaces) and less morbid, especially for multicomplicated obese and/or the super obese. However, this procedure is at risk of biliary reflux and anastomotic ulcers with dysplastic changes of the gastric and esophageal mucosa. ¹⁴ Many authors propose OAGB as a revisional procedure for weight regain after LSG. This option must be careful evaluated in terms of GERD as the esophagus have already had a potential acid exposure with LSG and with the OAGB will be exposed to the alkalin reflux. These modifications in term of the ph could be the trigger of dysplastic modifications of the mucosa at the level of the lower esophagus. As a result, OAGB remains a controversial procedure, especially when it is proposed as revisional surgery after LSG.

Single Anastomosis Duodeno-Ileostomy and Duodenal Switch

Single anastomosis duodeno-ileostomy (SADI) with sleeve gastrectomy is an easier and quicker version of the duodenal switch (DS). Given its effectiveness as a primary surgery, it is hypothesized as a successful second-step operation for patients with a suboptimal result after bypass or sleeve surgery. For DS, the extra weight loss is offset by a significant risk of protein or vitamin deficiency and a poorer quality of life from diarrhea. In SADI, the anastomosis between the duodenum and the small bowel is performed with a “common limb” measuring 3 m long, with reduction of bowel frequency compared with DS and similar EWL. ¹⁵ As revisional surgery, either SADI or DS have little or no impact on GERD and in our experience the indication for SADI/DS is a valid option in case of absence of any symptoms of reflux.

Sleeve Gastrectomy

LSG has evolved into a primary surgical treatment modality for morbid obesity. It has gained wide popularity as a sole bariatric procedure, now established as the most frequent bariatric procedure in France since 2011 and in the United States since 2013.^16,17 The effect of gastric resection for GERD could be contradictory. A systematic review analyzed 15 articles on the effect of LSG on GERD. Seven of these studies were in favor of positive effects of LSG over GERD, whereas four of them were against it. ¹⁸

The explanations for improving symptoms of GERD postoperatively were as follows:

Acceleration of gastric emptying at 6 months and 2 years after sleeve gastrectomy. ¹⁹

The reasons for a worsening of GERD symptoms after LSG were as follows:

The sleeve consensus conference ²² in 2012 bringing together experts on LSG working on a panel with >12,000 patients reported the prevalence of postoperative GERD of 12% (±9%). Furthermore, recommendations were issued such as:

There is an increasing evidence of an existing relationship between sleeve gastrectomy and the development of Barrett's esophagus in patients with no preoperative history of the disease. Although data are yet limited, there are several published studies that have shown the development of Barrett's esophagus at mid-term follow-up upper gastro-intestinal endoscopy.

Braghetto and Csendes ²³ reported first a 1.2% incidence of Barrett's esophagus (3 patients) in a cohort of 231 sleeve gastrectomy patients who did not have reflux symptoms, hiatal hernia, or Barrett's before surgery. Braghetto reported that BE was diagnosed between 5 and 6 years after surgery. All those 3 patients were later converted to Roux-en-Y gastric bypass. In another study, Genco et al. ²⁴ reported a new diagnosis of Barrett's esophagus in 19 out of 110 patients (17.2%) at mean of 58 months follow-up postgastric sleeve. In the same study, they reported only 14 patients out of 19 (73.6%) with GERD symptoms, indicating that the presence of symptoms did not correlate with the severity of esophageal disease. In a multicenter study, Sebastianelli et al. ²⁵ observed a prevalence of 18.8% for Barrett's esophagus postsleeve gastrectomy in patients with normal esophagus preoperatively. All patients but 1 complained of GERD symptoms and 35% required PPIs. No dysplasia was noted, and no significant difference was observed among centers. They also noticed a correlation between weight loss failure (defined as EWL <50%) and the presence of BE. Although the link between the degree of weight loss and presence of BE is still unclear, authors of this study proposed the hypothesis of a dilated sleeve leading to weight regain and increased GERD and secondly, the possibility of the modification of eating habits by patients suffering GERD symptoms to buffer acid.

There is still little follow-up on the long-term complications of GERD in postoperative sleeve gastrectomy: Felsenreich et al. ²⁶ carried out a full paraclinical evaluation of GERD 10 years after LSG, including upper endoscopy and pH-metry studies for 20 patients. The results showed de novo hiatus hernia in 45% of patients (n = 9/20) and development of Barrett's esophagus without dysplasia in 15% of patients (n = 3/20).

Given the slow nature of development of dysplasia and then to adenocarcinoma in the setting of BE, most authors found that there will be a room for a long and close endoscopic follow-up before attempting a conversion to a new bariatric procedure (most probably RYGB).

A New Concept—Nissen-Sleeve

The number of patients hesitating or refusing the choice for RYGBP because of long-term complications cannot be neglected, more than one-third of patients who underwent LRYGB had at least one complication within the 10-year follow-up period. ¹¹ LSG presents two complications such as gastric leak located at the angle of His or long-term GERD. This can cause a major limitation in quality of life despite the existing treatment of PPI or the option to perform a conversion to RYGBP. In addition, recent studies^24–26 have reported the occurrence of BE between 15% and 20% of patients with long-term endoscopic monitoring. As a result, LSG is most often contraindicated in morbidly obese patients with severe GERD or preoperative BE. Considering all these findings and encouraged by the good results of LSG and concomitant hiatal hernia repair,^27–29 we have developed a modification to the usual surgical technique of LSG by adding a Nissen fundoplication (N-Sleeve) to minimize both leaks and GERD.

After encouraging initial results of the preliminary study, ³⁰ a prospective trial was set up to assess the feasibility and the effectiveness of this new technique in a wider spectrum of indications. The potential benefit of the technique seems evident in the treatment or prevention of postoperative GERD. The Nissen technique has been described for a long time and is recognized for treating GERD. In addition, one of the additional benefits of N-Sleeve could be to avoid gastric fistulas located at the angle of His (stapling at a distance from the angle of His due to the creation of the valve), a gastric leak with a long and complex treatment.

The standard LSG is a restrictive procedure and very often the results are correlated to the amount of the gastric resection. The N-Sleeve was incriminated for not achieving similar results in terms of weight loss due to the nonresected used for the valve. The fundoplication is no longer functional for storing the bolus and it acts similar to a standard valve of a Nissen procedure (containing only air). The gastric volume is also calibrated on a tube that is in place during the realization of the valve and during stapling. The realization of a N-Sleeve thus does not modify the “restriction” properties of the surgery compared with a standard LSG.

For those with moderate reflux, since specific procedure guidelines are missing, surgical treatment for morbid obese patients must be selected according to the clinical characteristics of the patient, his eating habits and patient willingness. It should be based on a preoperative workup with shared decision making, with the double purpose of treating both GERD and obesity.