Long-term consequences of one anastomosis gastric bypass on esogastric mucosa in a preclinical rat model

No Long-Term Mucosal Lesions in the Esophagus but More Gastric Mucosal Lesions after Sleeve Gastrectomy in Obese Rats

Sleeve gastrectomy (SG) often induces gastroesophageal reflux, with few and discordant long-term data on the risk of Barrett's esophagus (BE) in operated patients. The aim of this study was to analyze the impact of SG on esogastric mucosa in a rat model at 24 weeks postoperatively, which corresponds to approximately 18 years in humans. After 3 months of a high-fat diet, obese male Wistar rats were subjected to SG (n = 7) or sham surgery (n = 9). Esophageal and gastric bile acid (BA) concentrations were measured at sacrifice, at 24 weeks postoperatively. Esophageal and gastric tissues were analyzed by routine histology. The esophageal mucosa of the SG rats (n = 6) was not significantly different in comparison to that of the sham rats (n = 8), with no esophagitis or BE. However, there was more antral and fundic foveolar hyperplasia in the mucosa of the residual stomach 24 weeks after SG than in the sham group (p < 0.001). Luminal esogastric BA concentrations did not differ between the two groups. In our study, SG induced gastric foveolar hyperplasia but no esophageal lesions at 24 weeks postoperatively in obese rats. Therefore, long-term endoscopic esophageal follow-up that is recommended in humans after SG to detect BE may also be useful for detecting gastric lesions.

Comparing Patient Selection and 30-day Outcomes Between Single Anastomosis Gastric Bypass and Roux-en-Y Gastric Bypass: a Retrospective Cohort Study of 47,384 Patients

PURPOSE

Single anastomosis gastric bypass (SAGB) offers a novel bariatric procedure with increasing popularity. However, its adoption, patient selection, and short-term safety remain poorly characterized.

MATERIALS AND METHODS

The 2020 Metabolic and Bariatric Accreditation and Quality Improvement Program (MBSAQIP) was analyzed comparing SAGB to Roux-en-Y gastric bypass (RYGB). Bivariate analysis and multivariable logistic regression models compared difference between groups and factors associated with 30-day serious complications and mortality.

RESULTS

Overall, 47,384 patients were evaluated, with 1344 (2.8%) undergoing SAGB. SAGB patients had a higher BMI (45.2 ± 7.6 kg/m² vs 44.6 ± 7.9 kg/m², p = 0.006) and younger age (44.3 ± 12.1 years vs. 45.4 ± 11.5 years, p = 0.0008) than RYGB patients respectively. SAGB patients were less likely to have GERD (42.6% SAGB vs. 45.7% RYGB, p = 0.02), sleep apnea (37.8% SAGB vs. 41.1% RYGB, p = 0.02), and chronic steroid use (1.3% SAGB vs. 2.2% RYGB, p = 0.04). There were no significant difference in diabetes, hypertension, or dyslipidemia rates. Operative length for SAGB was significantly less than for RYGB (101 ± 53.7 min SAGB vs. 131.5 ± 63.3 min RYGB, p < 0.0001). SAGB was independently associated with decreased serious complications (4.7% vs. 8.4%, p < 0.0001) within 30 days compared to RYGB. Additionally, SAGB patients were less likely to experience reoperation (1.6% vs. 2.6%, p = 0.03), and readmission (2.2 vs. 5.8%, p < 0.0001) compared to RYGB respectively.

CONCLUSIONS

Compared to RYGB, patients undergoing SAGB were younger with marginally higher BMI. After adjusting for comorbidities, SAGB was associated with decreased odds of serious complications. Ongoing prospective studies analyzing long-term outcomes following SAGB remain needed.

Advancements in photodynamic therapy of esophageal cancer

The poor prognosis of patients with esophageal cancer leads to the constant search for new ways of treatment of this disease. One of the methods used in high-grade dysplasia, superficial invasive carcinoma, and sometimes palliative care is photodynamic therapy (PDT). This method has come a long way from the first experimental studies to registration in the treatment of esophageal cancer and is constantly being improved and refined. This review describes esophageal cancer, current treatment methods, the introduction to PDT, the photosensitizers (PSs) used in esophageal carcinoma PDT, PDT in squamous cell carcinoma (SCC) of the esophagus, and PDT in invasive adenocarcinoma of the esophagus. For this review, research and review articles from PubMed and Web of Science databases were used. The keywords used were "photodynamic therapy in esophageal cancer" in the years 2000-2020. The total number of papers returned was 1,000. After the review was divided into topic blocks and the searched publications were analyzed, 117 articles were selected.

The United States Experience with One Anastomosis Gastric Bypass at MBSAQIP-Accredited Centers

PURPOSE

One anastomosis gastric bypass (OAGB) has emerged as a potentially safe and effective weight-loss procedure. Worldwide, OAGB is the third most commonly performed primary bariatric procedure, comprising 4% of the annual volume. In the USA, OAGB has yet to be endorsed as a primary bariatric procedure and can only be performed under research protocols or as a revision procedure.

MATERIALS AND METHODS

We performed an observational cohort study to describe the preoperative, intraoperative, and postoperative characteristics of adult patients who underwent primary or revision OAGB from 2015 to 2019 at MBSAQIP centers. Exclusion criteria included emergent surgery, incomplete 30-day follow-up, and non-laparoscopic- or robotic approach.

RESULTS

During the study period, 803,906 bariatric procedures were performed and 645 (0.08%) were OAGB. Among these, 436 (67.6%) were primary and 209 (32.4%) were revision OAGB. The mean operation time was 89 min (SD, 59) and 8% were performed using a robotic approach. The overall complication rate was 7.4% and there was one death (0.2%). The post-operative complication rates were generally higher than the early complication rate (3.4%) reported in the YOMEGA trial, an RCT from France. Revision OAGB had a longer mean operation time of 141 min (SD, 85, p < 0.001).

CONCLUSION

Primary OAGB was a rarely performed bariatric procedure at MBSAQIP-accredited centers comprising only 0.05% compared to 4% worldwide. Future studies should compare safety of OAGB to that of established bariatric procedures like Roux-en-Y gastric bypass and sleeve gastrectomy.

Shortening the Biliopancreatic Limb Length of One Anastomosis Gastric Bypass Maintains Glucose Homeostasis Improvement with Limited Weight Loss

One anastomosis gastric bypass (OAGB) is associated with similar metabolic improvements and weight loss as Roux-en-Y gastric bypass (RYGB). However, this bariatric procedure is still controversial as it is suspected to result in undernutrition. Reducing the size of the biliopancreatic limb of OAGB could be essential to maintain positive outcomes while preventing side effects. The objective of this study was to compare and contrast outcomes of OAGB with two different biliopancreatic limb lengths to RYGB and Sham surgery in obese and non-obese rats. Lean and diet-induced obese Wistar rats were operated on RYGB, OAGB with a short (15 cm OAGB-15) or a long (35 cm OAGB-35) biliopancreatic limb or Sham surgery. Body weight and food intake were monitored over 30 weeks, and rats underwent oral glucose and insulin tolerance tests with a pancreatic and gut hormone secretion assay. Macronutrient absorption was determined by fecal analyses. Statistical analyses used non-parametric one-way or two-way ANOVA tests. Compared to Sham rats, RYGB, OAGB-15 and OAGB-35 rats displayed a significant reduced weight. Weight loss was greater after OAGB-35 than after OAGB-15 or Sham surgery because of transient malabsorption. All OAGB- and RYGB-operated rats displayed an improved pancreatic and gut hormone secretion in response to a meal compared to Sham rats, these effects were independent of limb length, rat weight, and maintained overtime. In conclusion, glucose homeostasis was similarly improved in obese and non-obese OAGB-15 and OAGB-35 rats suggesting that shortening the biliopancreatic limb can improve the metabolic parameters without a major influence on weight.

Gastroesophageal Cancer After Gastric Bypass Surgeries: a Systematic Review and Meta-analysis

Data comparing the occurrence of gastroesophageal cancer after gastric bypass procedures are lacking and are only available in the form of case reports. We perform in this study a systematic review and a meta-analysis of all the reported cases of gastroesophageal cancer following Roux-en-Y gastric bypass (RYGB) and loop gastric bypass-one anastomosis gastric bypass/mini gastric bypass (LGB-OAGB/MGB). We conducted a systematic review of all the reported cases in articles referenced in PubMed/Medline, Cochrane, and Scholar Google. Only cases of gastro-esophageal adenocarcinoma following RYGB or LGB-OAGB/MGB are included. Statistical analysis was done accordingly. Fifty cases were identified, along with 2 reported in this paper. Sixty-one percent (27/44) of the cancers after RYGB were in the gastric tube compared to 37.5% (3/8) after LGB-OAGB/MGB. This resulted in an odds ratio of 0.38 (p-value = 0.26), which failed to prove an increase in cancer occurrence in the gastric tube after LGB-MGB/OAGB compared to RYGB. The most common symptoms were dysphagia for cancers occurring in the gastric tube (15/30) and abdominal pain for those occurring in the excluded stomach (10/22). Twenty-nine/thirty of the cancers in the gastric tube were diagnosed by gastroscopy and 13/22 of the cancers in the excluded stomach were diagnosed by CT scan. Gastroesophageal cancers after gastric bypass procedures occur commonly in the excluded stomach where many are not identified by conventional means. Physician awareness and patient education as well as lifelong follow-up are essential for maintaining bypass surgeries on the beneficial side.

Analysis of Risk Factors and Establishment of a Prediction Model for Endoscopic Primary Bile Reflux: A Single-Center Retrospective Study

Background: Endoscopic primary bile reflux is one of the main diagnostic criteria for bile reflux gastritis (BRG). Presently, the risk factors and prediction models of endoscopic primary bile reflux (EPBR) in gastropathy patients who cannot or will not undergo endoscopy due to contraindications are not clear. Thus, this study aimed to evaluate the risk factors of EPBR and to establish and verify a prediction model.

Methods: A series of 844 patients (564 subjects with EPBR and 280 control subjects) were retrospectively selected for this study and divided into a training set (n = 591) and a validation set (n = 253) according to the usual ratio of 70:30% for the subsequent internal validation of the logistic regression model for EPBR. Fifteen parameters that might affect the occurrence of EPBR were collected. Subsequently, univariate and stepwise logistic regression analyses were introduced to reveal the risk factors and the multivariate prediction model. An R package was dedicated to the corresponding internal validation of the EPBR model.

Results: The univariate analysis showed that gender, age, smoking, Helicobacter pylori (H. pylori) infection status, metabolic syndrome (MS), non-steroidal anti-inflammatory drugs (NSAIDs) use history, and previous medical histories of chronic liver diseases, cholelithiasis, and erosive gastritis were statistically significant between the two groups (P < 0.05). Multivariate regression described that being a male [OR (95%confidence interval (CI)) = 2.29 (1.50–3.50), P < 0.001], age≥45 years old [OR (95% CI) = 4.24 (2.59–6.96), P < 0.001], H. pylori infection status [OR (95% CI) = 2.34 (1.37–4.01), P = 0.002], MS [OR (95% CI) = 3.14 (1.77–5.54), P < 0.001], NSAIDs use history [OR (95% CI) = 1.87 (1.03–3.40), P = 0.04], cholelithiasis history [OR (95% CI) = 3.95 (2.18–7.18), P < 0.001] and erosive gastritis history [OR (95% CI) = 6.77 (3.73–12.29), P < 0.001] were the risk factors for the occurrence of EPBR. Based on the results of these risk factors, an EPBR prediction model with an adequate calibration and excellent discrimination was established [area under the curve (AUC): 0.839, 95% CI = 0.806–0.872].

Conclusions: Being a male, age ≥ 45 years old, H. pylori infection, histories of MS, NSAIDs use, cholelithiasis, and erosive gastritis appear to be the risk factors for EPBR, and our favorable prediction model might be an option for the prediction of EPBR.