Epithelial Cell Turnover Is Increased in the Excluded Stomach Mucosa After Roux-en-Y Gastric Bypass for Morbid Obesity

Helicobacter pylori-negative extra-nodal marginal zone B-cell lymphoma of Mucosa-Associated Lymphoid Tissue (MALT) type following Roux-en-Y Gastric Bypass (RYGB)

Gastric MALT lymphoma is a common type of non-Hodgkin's lymphoma that has the potential for cure in patients found to have concomitant Helicobacter pylori (H. pylori) infection. This case report explores the evaluation, diagnosis, and treatment of H. pylori-negative MALT lymphoma in a patient with a history of a RYGB.

Sleeve gastrectomy-induced endocrine changes in the remnant stomachs of premenopausal and postmenopausal rats: role of the estrogen receptors

BACKGROUND

Although alterations in the plasma levels of leptin, glucagon-like peptide-1, and gastrin were linked with bariatric surgery outcomes, gastric production of these peptides was not elucidated before.

OBJECTIVE

The aim was to evaluate the impact of estrogen depletion and estrogen receptors (ERs) on sleeve gastrectomy (SG)-induced alterations in gastric hormone production, gastric mucosal integrity, and bone mass.

SETTING

Physiology Research Lab at the University.

METHODS

Female Sprague-Dawley rats underwent ovariectomy or sham operation (control), and 2 months later SG or sham SG was performed. Rats received either nonselective agonist 17 β, ER-α agonist, ER-β agonist, or vehicle for 3 weeks. Trunk blood and gastric tissues were collected for biochemical measurements, while histopathologic examination was performed in gastric and femur samples.

RESULTS

In the presence of intact ovaries, SG-induced weight loss was accompanied by reductions in the gastric synthesis of leptin and gastrin, while gastric glucagon-like peptide-1 was additionally decreased when SG was performed at the postmenopausal state. SG elevated the depleted serum estradiol levels of menopause, implicating a beneficial effect, but the occurrence of severe gastric mucosal injury was triggered. On the other hand, using ER agonists upregulated gastrin-expressing cells, ameliorated gastric injury, and improved bone loss.

CONCLUSIONS

SG, either at premenopausal or postmenopausal state, resulted in considerable loss in bone mass, along with reductions in the gastric levels of gastrin and leptin. Functional status of the ovaries needs to be taken into consideration when monitoring the outcomes of SG, and ER agonists could be of value in controlling SG-induced complications.

Omeprazole Absorption and Fasting Gastrinemia After Roux-en-Y Gastric Bypass

PURPOSE

Roux-en-Y gastric bypass (RYGB) is one of the bariatric surgeries most frequently performed worldwide. Since this operation may predispose to the formation of peptic ulcer of the gastrojejunal anastomosis, the use of proton pump inhibitors (PPI) is recommended during the first postoperative year. However, so far, there is no detailed knowledge about the absorption of this medication during the immediate postoperative period and consequently about its effectiveness in blocking acid secretion. The objective was to assess the possible endoscopic peptic changes, the absorption of omeprazole (OME), and the status of fasting gastrinemia before and after RYGB operation.

MATERIALS AND METHODS

OME absorption, the production of its metabolites omeprazole sulfone (OMES) and 5-hydroxyomeprazole (HOME), and basal (fasting) gastrinemia were determined in patients submitted to RYGB before and 2 months after the operation. Upper digestive endoscopy (UDE) was also performed before and 6 months after the operation.

RESULTS

Twenty patients were studied. Preoperatively, all these patients had some peptic changes and 55% tested positive for Helicobacter pylori. Six months after surgery, ten patients still showed endoscopic changes and one patient tested positive for H. pylori. During the postoperative period, there was a reduction of OME absorption and of the production of its metabolites 90 min after administration of the drug, and reduction of serum gastrin levels.

CONCLUSION

The standard OME dose (40 mg) administered after bariatric surgery is insufficient to achieve serum levels that can effectively block the production of hydrochloric acid, permitting the formation of peptic injuries in many patients.

Fecal Calprotectin, Elastase, and Alpha-1-Antitrypsin Levels After Roux-en-Y Gastric Bypass; Calprotectin Is Significantly Elevated in the Majority of Patients

BACKGROUND

Roux-en-Y gastric bypass (RYGB) causes several alterations in gastrointestinal function. We hypothesized that levels of three commonly used fecal tests change after RYGB.

METHODS

Fecal levels of calprotectin, elastase, and alpha-1-antitrypsin were determined in 122 patients without signs of gastrointestinal disease 1 to 2 years after RYGB. Medians, distribution of values, and the percentage of patients with levels above or below reference values were determined.

RESULTS

Median fecal calprotectin level was 163.5 (<30-1587) μg/g; in 87 % of patients, it was above the reference value (<50 μg/g). Median fecal elastase level was 444 (<15-647) μg/g; 13 % was below the reference value (>200 μg/g). Median fecal alpha-1-antitrypsin level was 0.51 (<0.20-2.20) mg/g, comparable to the reference values.

CONCLUSIONS

Fecal calprotectin levels are significantly higher than the reference value in most patients after RYGB. Fecal elastase is significantly lower. This might indicate that the validity of fecal calprotectin testing is impaired after RYGB and the specificity for fecal elastase is decreased. Clinical awareness of altered fecal markers after RYGB is essential to prevent unnecessary diagnostic tests, such as colonoscopy. Fecal alpha-1-antitrypsin is not influenced by RYGB.

Potential Hormone Mechanisms of Bariatric Surgery

PURPOSE OF REVIEW

In recent years, the role of the gastrointestinal (GI) tract in energy homeostasis through modulation of the digestion and absorption of carbohydrates and the production of incretin hormones is well recognized.

RECENT FINDINGS

Bariatric surgery for obesity has been a very effective method in substantially improving weight, and numerous studies have focused on intestinal adaptation after bariatric procedures. A number of structural and functional changes in the GI tract have been reported postsurgery, which could be responsible for the altered hormonal responses. Furthermore, the change in food absorption rate and the intestinal regions exposed to carbohydrates may affect blood glucose response. This review hopes to give new insights into the direct role of gut hormones, by summarising the metabolic effects of bariatric surgery.

Effect of Endoscopic Gastroplication on the Genome-Wide Transcriptome in the Upper Gastrointestinal Tract

BACKGROUND

Bariatric surgery is an effective intervention strategy in obesity, resulting in sustained weight loss and a reduction of comorbidities. Gastroplication, using the articulating circular endoscopic stapler, was recently introduced as a transoral bariatric technique. This procedure reduces gastric volume and induced 34.9 % of excess weight loss in the first year (Paulus et al. Gastrointest Endosc. 81(2):312-20, 3). The aim of the present study was to gain insight in the long-term effects and underlying mechanisms of gastroplication by investigating differences in the genome-wide gastric and duodenal transcriptome before and 1 year after intervention.

METHODS

Ten morbidly obese patients (BMI 39.8 ± 0.9 kg/m2 (mean ± SEM)) underwent gastroplication. Previous to the procedure and after 1 year, blood samples were taken, and mucosal biopsies were collected from the fundus, antrum and duodenum. Gene expression was measured using microarray analysis. Plasma adiponectin, HbA1c, IL-1β, IL-6, IL-7, TNF-α, IFN-γ, MCP-1, IL-8, TGF-1 and CRP levels were determined.

RESULTS

Downregulation of inflammatory genes and gene sets was observed in the fundus and duodenum 1 year after surgery. Gene expression of ghrelin and its activating enzyme GOAT were downregulated in the upper gastrointestinal tract. Patients showed a reduction in plasma HbA1c levels (from 6.17 ± 0.51 to 5.32 ± 0.14 %, p = 0.004) and an increase of plasma adiponectin (from 16.87 ± 3.67 to 27.67 ± 5.92 μg/ml, p = 0.002).

CONCLUSIONS

Individuals undergoing gastroplication displayed a downregulation of inflammatory tone in the stomach and duodenum, which coincided with improved HbA1c and adiponectin levels. The reduction of inflammatory tone in the upper gastrointestinal tract may be a consequence of an improved metabolic health status or alternatively caused by the procedure itself.

H. PYLORI INFECTION, ENDOSCOPIC, HISTOLOGICAL ASPECTS AND CELL PROLIFERATION IN THE GASTRIC MUCOSA OF PATIENTS SUBMITTED TO ROUX-EN-Y GASTRIC BYPASS WITH CONTENTION RING: a cross sectional endoscopic and immunohistochemical study

BACKGROUND

Morbid obesity treatment through vertical gastroplasty Roux-en-Y gastric bypass initially used a contention ring. However, this technique may create conditions to the development of potentially malign alterations in the gastric mucosa. Although effective and previously performed in large scale, this technique needs to be better evaluated in long-term studies regarding alterations caused in the gastric mucosa.

OBJECTIVE

To analyze the preoperative and postoperative endoscopic, histological and cell proliferation findings in the gastric antrum and body mucosa of patients submitted to the Roux-en-Y gastric bypass with a contention ring.

METHODS

We retrospectively evaluated all patients submitted to Roux-en-Y gastric bypass with a contention ring with more than 60 months of postoperative follow-up. We compared the preoperative (gastric antrum and body) and postoperative (gastric pouch) gastric mucosa endoscopic findings, cell proliferation index and H. pylori prevalence. We evaluated cell proliferation through Ki-67 antibody immunohistochemical expression.

RESULTS

In the study period, 33 patients were operated with the Roux-en-Y gastric bypass using a contention ring. We found a chronic gastritis rate of 69.7% in the preoperative period (gastric antrum and body) and 84.8% in the postoperative (gastric pouch). H. pylori was present in 18.2% of patients in the preoperative period (gastric antrum and body) and in 57.5% in the postoperative (gastric pouch). Preoperative cell proliferation index was 18.1% in the gastric antrum and 16.2% in the gastric body, and 23.8% in the postoperative gastric pouch. The postoperative cell proliferation index in the gastric pouch was significantly higher (P=0.001) than in the preoperative gastric antrum and body. Higher cell proliferation index and chronic gastritis intensity were significantly associated to H. pylori presence (P=0.001 and P=0.02, respectively).

CONCLUSION

After Roux-en-Y gastric bypass with contention ring, there was a higher chronic gastritis incidence and higher cell proliferation index in the gastric pouch than in the preoperative gastric antrum and body. Mucosa inflammation intensity and cell proliferation index in the postoperative gastric pouch were associated to H. pylori presence and were higher than those found in the preoperative gastric antrum and body mucosa.

Increased Proliferative Activity Accompanies the Local Inflammatory Response of Gastric Mucosa After Intragastric Balloon Insertion

BACKGROUND AND AIM

The use of BioEnterics intragastric balloon (BIB) is progressively increasing, owing to the fact that morbid obesity becomes a global epidemic together with risks of bariatric surgery. Yet, the possible local BIB effect on gastric mucosa is not clearly elucidated. The aim of the current study was to assess the histological changes occurring in the gastric mucosa post-BIB insertion.

METHODS

Gastric mucosa biopsy was obtained from 87 cases of morbid obesity both pre-BIB and 6 months post-BIB insertion to compare the local changes by histological and immunohistochemical analysis.

RESULTS

An inflammatory reaction was detected in the post-BIB mucosa which displayed a positive CD20, CD3 (p < 0.05), and the proliferation index (Ki67) increased significantly compared with that of the pre-BIB cases. The Ki67 index showed a significant positive correlation with CD20 and CD3 immunoexpression in the post-BIB gastric mucosae.

CONCLUSION

Our results demonstrated a possible increase in the gastric proliferative activity after BIB insertion accompanied with a remarkable local inflammatory reaction. Although these findings may be reactive and transient, endoscopic follow-up is recommended for early detection of further pathological changes.

The Gastric Remnant in Roux-en-Y Gastric Bypass: Challenges and Possibilities

Laparoscopic Roux-en-Y gastric bypass (RYGB) is widely applied in the treatment of morbid obesity. Health personnel meeting these patients should thus be familiar with the potential clinical consequences of the modified anatomy induced by the surgery. After a RYGB, the stomach is left in situ after the closure of the upper part of the organ. This blind-ended gastric remnant may cause complications and surgical emergencies, but also opportunities for diagnostic and therapeutic intervention. The present review focuses on complications related to the gastric remnant including bleeding and acute dilatation in the early postoperative period and later adverse events such as gastroduodenal peptic disease, tumors, gastrogastric fistulas, and late dilatation. Opportunities offered by the remnant, including minimal invasive or open access for enteral nutrition, and therapeutic and diagnostic access to the bile ducts, the duodenum, and the gastric remnant, which is challenged by the modified anatomy, are discussed. Reversal of the gastric bypass and gastrointestinal reconstruction after esophageal resection have been commented on. The review aims to improve the awareness of issues related to the gastric remnant for physicians involved in the treatment and the follow-up of patients after a RYGB.

The effect of bariatric surgery on gastrointestinal and pancreatic peptide hormones

Bariatric surgery for obesity has proved to be an extremely effective method of promoting long-term weight reduction with additional beneficial metabolic effects, such as improved glucose tolerance and remission of type 2 diabetes. A range of bariatric procedures are in common use, including gastric banding, sleeve gastrectomy and the Roux-en-Y gastric bypass. Although the mechanisms underlying the efficacy of bariatric surgery are unclear, gastrointestinal and pancreatic peptides are thought to play an important role. The aim of this review is to summarise the effects of different bariatric surgery procedures upon gastrointestinal and pancreatic peptides, including ghrelin, gastrin, cholecystokinin (CCK), glucose-dependent insulinotropic hormone (GIP), glucagon-like peptide 1 (GLP-1), peptide YY (PYY), oxyntomodulin, insulin, glucagon and somatostatin.

INFLAMMATORY DISORDERS ASSOCIATED WITH HELICOBACTER PYLORI IN THE ROUX-EN-Y BYPASS GASTRIC POUCH

Background

The prevalence of Helicobacter pylori in obese candidates for bariatric surgery and its role in the emergence of inflammatory lesions after surgery has not been well established.

Aim

To identify the incidence of inflammatory lesions in the stomach after bariatric surgery and to correlate it with H. pylori infection.

Methods

This is a prospective study with 216 patients undergoing Roux-en-Y gastric bypass. These patients underwent histopathological endoscopy to detect H. pylori prior to surgery. Positive cases were treated with antibiotics and a proton inhibitor pump followed by endoscopic follow-up in the 6th and 12th month after surgery.

Results

Most patients were female (68.1%), with grade III obesity (92.4%). Preoperative endoscopy revealed gastritis in 96.8%, with H. pylori infection in 40.7% (88/216). A biopsy was carried out in 151 patients, revealing H. pylori in 60/151, related to signs of inflammation in 90% (54/60). In the 6th and 12th month after surgery, the endoscopy and the histopathological exam showed a normal gastric pouch in 84% of patients and the incidence of H. pylori was 11% and 16%, respectively. The presence of inflammation was related to H. pylori infection (p<0,001).

Conclusion

H. pylori has a similar prevalence in both obese patients scheduled to undergo bariatric surgery and the general population. There is a low incidence of it in the 6th and 12th months after surgery, probably owing to its eradication when detected prior to surgery. When inflammatory disease is present in the new gastric reservoir it is directly related to H. pylori infection.

Remodeling of the residual gastric mucosa after roux-en-y gastric bypass or vertical sleeve gastrectomy in diet-induced obese rats

Whereas the remodeling of intestinal mucosa after bariatric surgeries has been the matter of numerous studies to our knowledge, very few reported on the remodeling of the residual gastric mucosa. In this study, we analyzed remodeling of gastric mucosa after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) in rats. Diet-induced obese rats were subjected to RYGB, VSG or sham surgical procedures. All animals were assessed for food intake, body-weight, fasting blood, metabolites and hormones profiling, as well as insulin and glucose tolerance tests before and up to 5 weeks post-surgery. Remodeling of gastric tissues was analyzed by routine histology and immunohistochemistry studies, and qRT-PCR analyses of ghrelin and gastrin mRNA levels. In obese rats with impaired glucose tolerance, VSG and RYGB caused substantial weight loss and rats greatly improved their oral glucose tolerance. The remaining gastric mucosa after VSG and gastric pouch (GP) after RYGB revealed a hyperplasia of the mucous neck cells that displayed a strong immunoreactivity for parietal cell H⁺/K⁺-ATPase. Ghrelin mRNA levels were reduced by 2-fold in remaining fundic mucosa after VSG and 10-fold in GP after RYGB. In the antrum, gastrin mRNA levels were reduced after VSG in line with the reduced number of gastrin positive cells. This study reports novel and important observations dealing with the remaining gastric mucosa after RYGB and VSG. The data demonstrate, for the first time, a hyperplasia of the mucous neck cells, a transit cell population of the stomach bearing differentiating capacities into zymogenic and peptic cells.