One-Anastomosis Gastric Bypass Revision for Gastroesophageal Reflux Disease: Long Versus Short Biliopancreatic Limb Roux-en-Y Gastric Bypass.

PURPOSE: One-anastomosis gastric bypass (OAGB) may be associated with refractory gastroesophageal reflux disease (GERD). The nature of this GERD remains unclear. This complication can be treated either with an additional enteroenterostomy without shortening of gastric pouch (long biliopancreatic limb Roux-en-Y gastric bypass (L-BPL-RYGB)) or revision to conventional short biliopancreatic limb Roux-en-Y gastric bypass (S-BPL-RYGB). The objective of this study is to compare the aforementioned procedures in terms of efficacy on GERD symptoms. MATERIALS AND METHODS: Retrospective analysis between October 2012 and June 2020. RESULTS: Fifty-two patients underwent OAGB revision to S-BPL-RYGB (n = 21) or L-BPL-RYGB (n = 31) secondary to GERD. Investigation with pH impedance prior to revision was performed in 15 patients showing biliary reflux (BR) in 7 (46.6%), acid reflux (AR) in 6 (40%), and no confirmation in 2. Patients with AR had a revision to S-BPL-RYGB, whereas patients with BR underwent L-BPL-RYGB. Among the patients without pH metry results (n = 37), S-BPL-RYGB was performed for associated disabling digestive disorders or nutritional deficiencies. GERD was treated in 68% of patients with L-BPL-RYGB versus 95% of patients after S-BPL-RYGB. Patients, whose decision for revisional procedure was based on the results of pH impedance testing, did not reveal refractory GERD. CONCLUSION: L-BPL-RYGB seems appropriate in patients with BR, whereas conversion to S-BPL-RYGB should be preferred if AR is present.

Acid Reflux Is Common in Patients With Gastroesophageal Reflux Disease After One-Anastomosis Gastric Bypass.

INTRODUCTION: Patients with one-anastomosis gastric bypass (OAGB) can develop gastroesophageal reflux disease (GERD). The nature of this GERD (acid or biliary) remains unclear. OBJECTIVE: To assess the nature of GERD via impedance pH testing in patients presenting with reflux post OAGB. METHODS: Retrospective analysis of a prospectively collected database of 43 patients with OAGB backgrounds who developed postoperative GERD and were investigated with impedance pH monitoring between 2006 and 2019. RESULTS: Mean age was 52.48 ± 9 years. Mean body mass index (BMI) prior to OAGB was 46.82 kg/m2. None of these patients had clinical GERD before surgery. The median time interval between surgery and investigation with 24-h impedance pH monitoring was 64 (56) months. The mean BMI at the time of investigations was 32.67 ± 6.9 kg/m2. The type of reflux was acid in 13 (30.2%), non-acid (biliary) in 12 (27.9%), and mixed (acid and biliary) in 5 (11.6%) patients. However, it remained not confirmed in 13 (30.2%). Median DeMeester score was 48.95 (27.67) in patients with acid, 2.8 (7.4) in patients with biliary, and 28.7 (5.6) in patients with mixed reflux. Median percent of time spent with pH < 4 was 9.65 (8) in patients with acid, 0.6 (1.75) in patients with biliary, and 7.7 (3.9) in patients with mixed reflux. CONCLUSION: Acid reflux seems to be as common as bile reflux in patients presenting with GERD after OAGB. In case of revisional surgery for severe GERD post OAGB, 24-h impedance pH monitoring could be essential to determine the surgical procedure of choice.

The cycling of carbon into and out of dust.

Observational evidence seems to indicate that the depletion of interstellar carbon into dust shows rather wide variations and that carbon undergoes rather rapid recycling in the interstellar medium (ISM). Small hydrocarbon grains are processed in photo-dissociation regions by UV photons, by ion and electron collisions in interstellar shock waves and by cosmic rays. A significant fraction of hydrocarbon dust must therefore be re-formed by accretion in the dense, molecular ISM. A new dust model (Jones et al., Astron. Astrophys., 2013, 558, A62) shows that variations in the dust observables in the diffuse interstellar medium (n(H) < or = 10(3) cm(-3)), can be explained by systematic and environmentally-driven changes in the small hydrocarbon grain population. Here we explore the consequences of gas-phase carbon accretion onto the surfaces of grains in the transition regions between the diffuse ISM and molecular clouds (e.g., Jones, Astron. Astrophys., 2013, 555, A39). We find that significant carbonaceous dust re-processing and/or mantle accretion can occur in the outer regions of molecular clouds and that this dust will have significantly different optical properties from the dust in the adjacent diffuse ISM. We conclude that the (re-)processing and cycling of carbon into and out of dust is perhaps the key to advancing our understanding of dust evolution in the ISM.