Acid and nonacid gastroesophageal reflux after single anastomosis gastric bypass. An objective assessment using 24-hour multichannel intraluminal impedance-pH metry.

Background: Single anastomosis gastric bypass (SaGB) was introduced in 2001 as an alternative to "loop" gastric bypass. It was considered as a procedure that would eliminate alkaline reflux and associated esophagitis.

Objectives: Existing evidence about the postoperative incidence of gastroesophageal reflux (GERD) after SaGB is based on studies using symptom questionnaires. The aim of our study was to evaluate GERD 12 months after SaGB by using 24-hour multichannel intraluminal impedance pH metry (24-h MIIpH).

Setting: Surgical department of a university hospital METHODS: Morbidly obese candidates for SaGB underwent 24-hour MIIpH prior and 12 months after their bariatric procedure.

Results: There were 11 patients included in this prospective study. Results of 24-hour MIIpH revealed that DeMeester score (40.48 versus 24.16, P = .339) had an increasing trend 12 months after SaGB. Acid reflux episodes decreased, whereas nonacid reflux episodes increased postoperatively, both in proximal and distal esophagus. Total median bolus clearance time and acid clearance time increased. De novo GERD developed in 2 patients (28.6%) and worsening of already existing GERD developed in all patients with preoperative evidence of GERD.

Conclusion: The use of symptom questionnaires to assess postoperative GERD after SaGB may not accurately depict the real image. Twenty-four-hour MIIpH in 12 months after SaGB revealed an increase of total number of nonacid reflux episodes and a decrease of total number of acid reflux episodes, with longer duration of each acid reflux episode. Close postoperative follow-up with reflux testing and possibly endoscopy could eliminate the risk of complicated GERD.