Changes in the mucosa of the Roux-limb after gastric bypass surgery

Emma Spak (1) , Per Björklund (2) , Herbert F Helander (2) , Michael Vieth (3) , Torsten Olbers (2) , Anna Casselbrant (2) , Hans Lönroth (2) , Lars Fändriks (2)

1 Gastrosurgical research
2 Gastrosurgical research
3 Pathology

Abstract Aims: Roux-en-Y gastric bypass surgery is the most efficient treatment of morbid obesity but the mechanisms of action are still poorly understood. The aim of this study was to explore the Roux-limb mucosa after gastric bypass surgery, focusing on basic morphology and inflammation. Methods and Results: Jejunal mucosal samples from the Roux-limb were gathered from eight patients at time of surgery and six to eight months post-surgery. Histological evaluation of inflammation and morphometric investigations were performed, mitotic frequency was assessed using immunohistochemistry and inflammatory markers and Angiotensin (Ang) II receptors were detected using western blot. Mitotic frequency increased and villous surface area decreased in the Roux-limb mucosa but no signs of active inflammation were observed after surgery. Protein analyses showed increased levels of nicotineamide adenine dinucleotidephosphate (NADPH)-oxidase, myeloperoxidase (MPO) and the Ang II type 1(AT1) receptor after surgery, whereas the levels of inducible nitric oxide synthase (iNOS), nitrotyrosine and the Ang II type 2(AT2) receptor remained constant Conclusion: These results indicate that the phenotype of the jejunal mucosa changes once exposed to un-digested food and the increased microbial load in the Roux-limb after surgery.

Mots clés: Medicine

Emma Spak, Per Björklund, Herbert F Helander, Michael Vieth, Torsten Olbers, et al.. Changes in the mucosa of the Roux-limb after gastric bypass surgery. Histopathology, 2010, 57 (5), pp.680. ⟨10.1111/j.1365-2559.2010.03677.x⟩. ⟨hal-00589972⟩