ANTI-REFLUX PROCEDURES AFTER ROUX-EN-Y GASTRIC BYPASS

ABSTRACT 
Background:
 Roux-en-Y gastric bypass (RYGB) has been the choice of bariatric procedure for patients with symptomatic reflux - and is known to be effective in reducing the need for anti-reflux medication postoperatively. However, a small number of RYGB patients can still develop severe reflux symptoms that require a surgical intervention. 
Aim: To examine and describe the patient population that requires an anti-reflux procedure after RYGB evaluating demographics, characteristics, symptoms and diagnosis 
Methods:
 A retrospective chart review was performed on 32 patients who underwent a hiatal hernia repair and/or Nissen fundoplication after RYGB Jul 1st, 2014 and Dec 31st, 2019. Patients were identified using the MBSAQIP database and their electronic medical records were reviewed. 
Results:
 Most patients were female (n=29, 90.6%). The mean age was 52.8 years and the mean body mass index (BMI) was 34.1 kg/m2 at the time of anti-reflux procedure. Patients underwent the anti-reflux procedure at a mean of 7.9 years after the RYGB procedure. The mean percentage of excess BMI loss during the time between RYGB and anti-reflux procedure was 63.4%. 
Conclusions:
 Female patients with a significant weight loss may develop a severe reflux symptoms years after RYGB. Complaints of reflux after RYGB should not be overlooked. Careful follow-up and appropriate treatment (including surgical intervention) is needed for this population.

ABSTRACT -Background: Roux-en-Y gastric bypass (RYGB) has been the choice of bariatric procedure for patients with symptomatic refluxand is known to be effective in reducing the need for anti-reflux medication postoperatively. However, a small number of RYGB patients can still develop severe reflux symptoms that require a surgical intervention. Aim: To examine and describe the patient population that requires an antireflux procedure after RYGB evaluating demographics, characteristics, symptoms and

INTRODUCTION
In recent years, laparoscopic sleeve gastrectomy (LSG) became the most commonly performed bariatric procedure according to American Society for Metabolic and Bariatric Surgery 11 . Nevertheless, Roux-en-Y gastric bypass (RYGB) still constituted 17% of all bariatric procedures in 2018 11 . Up to 70% of preoperative bariatric patients suffer from gastroesophageal reflux disease (GERD) symptoms and between 5-50% of obese individuals are reported to have hiatal hernia 2,4 . Obese individuals are more prone to hiatal hernias and esophagitis secondary to unique changes in physiology as it pertains to increased intra-abdominal pressure 7 . They are more than four times as likely to have hiatal hernias than normal weight patients 26 . Several studies reviewed preoperative workup for these entities and ways to manage them at the time of initial bypass 2,13,24 .
The RYGB is a durable operation that has been demonstrated to be both effective for weight loss and reducing the need for anti-reflux medication postoperatively 1,3,24 .
However, a substantial number of patients, up to 22%, who undergo successful RYGB continued to complain of heartburn postoperatively 8 . Not many studies documented the prevalence of hiatal hernia following bariatric surgery nor the degree to which physiologic reflux develops following RYGB 12 . Pallati et al. 23 found that improvement in GERD score was significantly higher in RYGB when compared to sleeve gastrectomy. Nevertheless, RYGB is not free from postoperative reflux. Several case studies report findings of hiatal hernia causing symptoms ranging from abdominal pain to failure to thrive after a RYGB 12,6,16,18 . At our center, we observed RYGB patients complaining of severe GERD or dysphagia years after the primary procedure that required a surgical intervention.
This has the objective to review 32 patients who underwent an anti-reflux procedure such as hiatal hernia repair and/or Nissen fundoplication after RYGB evaluating the demographics of patients at the time of anti-reflux procedures after Rouxen-Y gastric bypass; characteristics of patients undergoing anti-reflux procedure after Roux-en-Y gastric bypass; presenting symptoms and diagnosis method for patients undergoing anti-reflux procedure after Roux-en-Y gastric bypass

After Institutional Review Board approval and following Health Insurance
Portability and Accountability Act Guidelines, all patients who underwent hiatal hernia repair and/or Nissen fundoplication after RYGB between July 1 st , 2014 and December 31 st , 2019 were identified using the MBSAQIP (Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program) database. A total of 32 patients were identified. Electronic medical records of these patients were retrospectively reviewed.
Presenting symptoms for the anti-reflux procedures included reflux, dysphagia, nausea and vomiting, and abdominal pain. Most patients were diagnosed using the upper gastrointestinal series (UGI) or both UGI and upper endoscopy. Some patients were diagnosed with hiatal hernia intra-operatively at the index RYGB.

Surgical technique
The procedures were performed at a single center by two experienced bariatric surgeons with over 10,700 procedures. Roux-en-Y gastric bypass was completed via robotic-assisted laparoscopy.

Statistical analysis
Descriptive statistics were used for data presentation. All data were demonstrated as frequency or mean and standard deviation unless otherwise noted. Median (lower quartile, upper quartile) were used when the normality assumption was violated. All statistical analyses were performed using SAS University Edition (SAS Institute, Cary, NC).

RESULTS
Patient characteristics included 90.6% female with a mean age of 52.8 years old and a mean BMI of 34.1 kg/m 2 at the time of anti-reflux procedures ( These patients underwent the anti-reflux procedure at a mean of eight years after the RYGB (Table 2). Where available, the mean BMI of these patients at the time of RYGB was 46.5 kg/m 2 , and the median percentage of excess BMI loss of these patients was

DISCUSSION
Our study shows that some patients can develop reflux symptoms after RYGB severe enough to require a surgical intervention. Reflux symptoms are generally considered as a common adverse event after LSG procedures; conversion to a RYGB is one of the options provided to patients with severe reflux symptoms after LSG 9 .
Preoperatively, patients with reflux symptoms are deterred from LSG and recommended to undergo RYGB as well 5,15 . The mechanism behind this rationale include low-pressure system, fewer acid-producing parietal cells in the smaller pouch, and longer alimentary limb preventing the return of biliopancreatic content 20 . Several large studies in the United States showed that 50-60% of RYGB patients had decreased reflux symptoms within one- year following the procedure 10,23,25 .
Nevertheless, in a recent large population-based cohort study, Holmberg et al. 17 suggested that the effectiveness of RYGB procedure on reflux symptoms may have been overstated. In their study of 2454 RYGB patients with pre-operative reflux symptoms, the prevalence of reflux requiring anti-reflux medication was approximately 68% during five years after the procedure.
They also pointed out that not many studies have demonstrated the long-term effect of RYGB on resolving reflux symptoms 23 . Of those that did, the sample sizes were small and the assessment of reflux symptoms could have introduced uncertainty of the internal validity 14,19,22 .
We think it is important to note the timing of developing and/or resolving reflux symptoms. In a recent review article, Crawford et al. 9 indicated that most reflux symptoms after LSG were observed within one-year after surgery. Considering that approximately 50% of patients had resolution of reflux symptoms within one-year after RYGB 17 , practicing surgeons may have the impression that RYGB is much superior than LSG in terms of resolving reflux symptoms. However, at our practice, we have observed many patients complaining of reflux symptoms years after RYGB. In fact, average time from RYGB to an anti-reflux procedure was eight years in this studyhighlighting the necessity of long-term follow-up on reflux symptoms after RYGB.
Holmberg et al. 17 identified that the use of a higher dose of anti-reflux medication prior to the RYGB procedure was the strongest indicator of persistent reflux symptoms after the procedure. Based on this report and our study, we believe RYGB should not be considered as a 'cure' for reflux symptoms in the bariatric populationand caution should be taken in absentmindedly proceeding with the procedure among patients taking high dose of anti-reflux medication preoperatively.
It is also important to note that only 6.3% (n=2) of these patients underwent hiatal hernia repair at the time of RYGB. This may indicate that surgeons should be more judicious in seeking out and aggressively treating hiatal hernias at the time of RYGB. As the aforementioned research has indicated, obese individuals are more likely to develop hiatal hernias even before undergoing bypass 7 . Although hiatal hernia repair at the time of RYGB may be more technically challengingobesity impairs reduction of the hiatal hernia sac, pillar identification and dissection, and tension-free closure of the hiatus 3patients may enjoy a better quality of life and avoid further surgical intervention for antireflux procedures.
This study demonstrates that patients experiencing severe reflux symptoms years after RYGB procedure can be safely and effectively treated with an anti-reflux procedure.
Most of our patients (81%) were free of symptoms at a mean follow-up of 18 months.
There are limitations in this research. First, this was a retrospective study with a small number of patients. We were not able to identify the true incidence of reflux symptoms in the RYGB population since the percentage of long-term follow-up was low and patients could have sought care from a different provider. Second, we only identified the timing of anti-reflux procedure when the symptoms could have started months and years prior. Only those who had symptoms severe enough to undergo an invasive intervention were captured in this study. Regardless, this study is one of few studies demonstrating the need for anti-reflux procedures after RYGB. We believe this adds an important viewpoint to practicing surgeons when they encounter patients with severe reflux symptoms before and after RYGB. A larger prospective, randomized study with longer follow-up is needed to assess the effectiveness of RYGB on reflux symptom.

CONCLUSIONS
Patients may develop severe reflux symptoms after RYGB. These patients may be safely and effectively treated with anti-reflux procedures. RYGB should not be considered the cure-all for reflux symptoms in the bariatric population. Further, prospective study of the true incidence of reflux and objective measures of symptoms early on may allow for better symptom management. Female patients with a significant weight loss may develop a severe reflux symptoms years after RYGB. Complaints of reflux after RYGB should not be overlooked. Careful follow-up and appropriate treatment (including surgical intervention) is needed for this population.