thereby increasing regurgitation or reflux of stomach contents into the esophagus with an intact pylorus. Additionally, laparoscopic sleeve gastrectomy results in a lower esophageal sphincter (LES) pressure and shortens the abdominal length of the esophagus [8]. Other potential causes may be iatrogenic in nature and are related to overlooking the presence of hiatal hernias and general shape of the sleeve, including over-dilation of the proximal part of the sleeve to create a reser­voir which may increase GERD [9, 10].

with Roux-en-Y anatomy, heartburn symptoms that fail to response to tradi­tional PPI therapy (classically higher dose PPI twice daily) should prompt inves­tigation for non-acid reflux. Due to the anatomy of Roux-en-Y gastric bypass, proper recognition of bile acid reflux with gastropathy or non-acid reflux as an alternative to GERD is important [14]. While the clinical diagnosis of GERD is based upon typical symptoms that respond to treatment with a PPI, more objec­tive measures including via 24 hour esophageal pH monitoring (diagnosed by having a pH < 4.0 and the length of time the esophagus is exposed to acid) may be helpful—especially for patients that may have no symptoms. Motility testing with pH and impedance testing along with manometry may also help to identify acid and non-acid reflux etiologies. Impedance testing is critical to differentiate acid versus non-acid reflux, thereby allowing proper identification of the underly­ing etiology. Esophageal manometry (i.e., motility testing) is also key as this may identify underlying functional disorders or explain difficult to control symptoms. Gastroenterologists and surgeons should collaborate in the care of these patients.

The first case of the ARMS procedure was reported in a pilot study of 10 patients with normal gastric anatomy by Inoue and colleagues in 2014 [16]. In this study, importantly among patients without sleeve gastrectomy, DeMeester score, Hill classification (hiatal hernia), and time of esophageal acid exposure (pH < 4), all significantly improved post-ARMS procedure. Perhaps most importantly, symptoms improved across the board with PPI therapy completely discontinued for all 10 patients. Notably, stenosis did develop in 10 patients requiring endos­copy balloon dilation with control of symptoms. A subsequent case report by our group demonstrated application of this novel ARMS technique in a sleeve gastrec­tomy patient with a relatively narrow stomach with altered blood supply [15]. In this case, a 71-year-old woman with sleeve gastrectomy approximately 5 years prior developed worsening GERD post-procedure despite twice daily PPI therapy. Step-by-step procedure details are shown in Fig. 1 with significant resolution of

symptoms at 12 month follow-up. While more data among a population of patients with prior bariatric surgery is needed, ARMS may provide an alternative to surgi­cal conversion to Roux-en-Y gastric bypass. At this time, use of ARMS is limited to tertiary academic centers with high volume endobariatric expertise.

Additionally, it has been demonstrated that severely obese patients are more likely to present with a motility disorder. This includes a low lower oesophageal sphincter resting pressure, nonspecific motility disorders, and nutcracker oesopha­gus, a diagnosis given to those patients who have a mean contraction amplitude of the lower oesophagus of greater than 180 mmHg. Whilst these features would likely increase the risk of GERD, the majority of these patients were found to be asymptomatic [11–13]. Importantly, SG itself can also lead to the develop­ment of GERD in patients following the operation through a separate mechanism. However, it is likely that GERD occurs as a result of a combination of pre-, intra­and post-operative factors.