Histological and microbiological findings of the defunctionalized loop in sleeve gastrectomy with jejunal bypass

Abstract Background Bariatric surgery produces anatomical changes in the digestive tract that can affect the intestinal microbiome and, in some cases, can cause small intestinal bacterial overgrowth (SIBO). Since the inception of the sleeve gastrectomy with jejunal bypass (SGJB) in 2004, there has been discussion regarding the possible development of those complications associated with the now abandoned jejunoileal bypass (JIB) procedure. Objectives The primary endpoint was to characterize the bacteriological and histopathological findings in the defunctionalized jejunal loop following the SGJB procedure and to analyze the liver profile. The secondary endpoint was to report SGJB conversions or reversions, and to review the differences between SGJB and JIB. Setting Academic medical center. Methods Prospective study of patients who underwent laparoscopy for any reason, having previously had an SGJB. A 5 cm segment at the proximal end of the excluded limb was resected. Luminal liquid and tissue samples were taken from this segment for aerobic and anaerobic cultures, and pathological examination of the bowel wall was performed to evaluate trophism and signs of chronic inflammation. Other variables were liver function and pre- and postoperative status. Finally, we retrospectively review the causes of revisional surgery in the prospective database. Results Eleven patients underwent laparoscopy. The median time after SGJB was 14 months (10-144 months). There were no complications from the procedure. Eight (72.7%) of the procedures were cholecystectomies. None of the patients showed histological alterations or signs of chronic infection. The liquid and tissue cultures were negative. The liver tests and the laparoscopic morphology of the liver were normal in all patients, except in one with previously documented liver cirrhosis. The number of SGJB revisions was 19 of 1074 (1.8 %), and all of them were converted to Roux-en-Y gastric bypass (RYGB) for severe gastroesophageal reflux. Conclusions In this study, we were unable to demonstrate the presence of symptoms or histological alterations that would suggest that patients undergoing SGJB develop SIBO in the short- and medium-term follow-up, unlike those who have undergone JIB. The study constitutes an initial step towards establishing what happens to the defunctionalized jejunal limb as a result of this surgical technique.