Diagnostic Criteria for Gastro-esophageal Reflux Following Sleeve Gastrectomy

Modified One Anastomosis Gastric Bypass Following Sleeve Gastrectomy for Severe Reflux and Delayed Gastric Emptying: A Prospective Trial with Clinical and Physiological Outcome Measures

BACKGROUND

Gastro-esophageal reflux (GORD) following sleeve gastrectomy (SG) is a central challenge, and precise indications for revisional surgery or the physiology have not been precisely defined. We aimed to determine whether OAGB performed for reflux post-SG (1) accelerates gastric emptying half-time, (2) reduces the frequency and severity of reflux events, and (3) improves reflux symptoms.

METHODS

We undertook a prospective trial (ACTRN12616001089426). There were 22 participants who underwent measurement before and after revisional surgery with 29 optimal SG (patients with optimal outcome from their primary surgery) as controls. All participants underwent a protocolized nuclear scintigraphy, 24-h pH monitoring, and gastroscopy and completed objective questionnaires.

RESULTS

Trial patients were 90.9% female, age 44.4 years. Conversion from SG to OAGB was at a median of 45.2 ± 19.6 months. Scintigraphy showed an increased rate of gastric emptying post-OAGB 34 (IQR 14) vs 24 (IQR 10.3) min, p-value 0.008, with decreased number of reflux events post-prandially (39 (IQR 13) vs 26 (IQR 7), p-value 0.001). This data correlated with the pH analysis; total acid events substantially reduced post-OAGB 58.5 (IQR 88) vs 12 (IQR 9.4) events, p-value 0.017. Endoscopic findings indicated a reduction in incidence of bile stasis 72.7% vs 40.9% post-OAGB, p-value < 0.00010. Post-OAGB, patients experienced less frequent regurgitation (12 ± 4.1 vs. 5.5 ± 3, p-value 0.012) and reflux (37.1 ± 15.7 vs. 16.8 ± 12.6, p-value 0.003).

CONCLUSIONS

We found OAGB is an effective treatment for reflux associated with delayed gastric emptying post-SG. The likely mechanisms is by, an increase in the rate of gastric clearance and reduced reflux events and overall esophageal acid exposure. This suggests that some forms of post-SG reflux are driven by slower emptying of the residual stomach and are amenable to treatment with drainage above the incisura.

Gastroesophageal reflux after sleeve gastrectomy: The dimension of the problem

Sleeve gastrectomy is a safe and effective bariatric surgery in terms of weight loss and longterm improvement or resolution of comorbidities. However, its achilles heel is the possible association with the development with the novo and/or worsening of pre-existing gastroesophageal reflux disease. The anatomical and mechanical changes that this technique induces in the esophagogastric junction, support or contradict this hypothesis. Questions such as «what is the natural history of gastroesophageal reflux in the patient undergoing gastric sleeve surgery?», «how many patients after vertical gastrectomy will develop gastroesophageal reflux?» and «how many patients will worsen their previous reflux after this technique?» are intended to be addressed in the present article.

Post Sleeve Reflux: indicators and impact on outcomes

INTRODUCTION

Post-operative gastroesophageal reflux disease (GERD) remains a significant morbidity following sleeve gastrectomy (SG). We aim to evaluate the incidence and impact within a single center experience.

MATERIALS AND METHODS

A retrospective review of a prospectively maintained database was performed identifying laparoscopic or robotic SG patients. Primary outcomes included weight loss, rates of post-operative GERD (de-novo or aggravated), and re-intervention. Subgroup analysis was performed between patients with (Group 1) and without (Group 2) post-operative GERD. De-novo GERD and aggravated was defined as persistent GERD complaints or new/increased PPI usage in GERD naive or prior GERD patients, respectively.

RESULTS

392 patients were identified between 2014 and 2019. Average demographics: age 42.3 (18-84) years, Charlson Comorbidity Index (CCI) 1.12 (0-10), and body mass index (BMI) 47.7 (28-100). 98% were performed laparoscopically. Average excess weight loss (EWL) was 51.0% and 46.4% at 1 and 2 years post-operatively. Average follow up was 516 (6-2694) days. 69 (17%) patients developed post operative de-novo or aggravated GERD. Group 1 had significantly higher EWL at 9 months (57% vs 47%, p 0.003). 13 (3%) patients required operative re-intervention for GERD and other morbidities: 4 RYGB conversions, 4 diagnostic laparoscopies, 3 HHR, 1 MSA placement. Group 1 had higher rates of post-operative intervention (14% vs 1%, p 0.0001). Subanalysis demonstrated that Group 1 had elevated preoperative DeMeester scores on pH testing (34.8 vs 18.9, p 0.03). De-novo GERD had an elevated post-operative total acid exposure when compared to aggravated GERD (12.7% vs 7.0% p 0.03). No significant differences were found between preoperative endoscopy findings, pre and postoperative total acid exposure, post-operative DeMeester scores, and high-resolution manometry values regarding de-novo/aggravated GERD development.

CONCLUSION

Preoperative DeMeester scores may serve as risk indicators regarding post-operative GERD. Outcomes such as reintervention remain elevated in post-operative GERD patients.

Mechanism of Staple Line Leak After Sleeve Gastrectomy via Isobaric Pressurisation Concentrating Stress Forces at the Proximal Staple Line

Purpose

Staple line leak following sleeve gastrectomy is a significant problem and has been hypothesised to be related to hyperpressurisation in the proximal stomach. There is, however, little objective evidence demonstrating how these forces could be transmitted to the luminal wall. We aimed to define conditions in the proximal stomach and simulate the transmission of stress forces in the post-operative stomach using a finite element analysis (FEA).

Materials and Methods

The manometry of fourteen patients post sleeve gastrectomy was compared to ten controls. Manometry, boundary conditions, and volumetric CT were integrated to develop six models. These models delineated luminal wall stress in the proximal stomach. Key features were then varied to establish the influence of each factor.

Results

The sleeve gastrectomy cohort had a significantly higher peak intragastric isobaric pressures 31.58 ± 2.1 vs. 13.49 ± 1.3 mmHg (p = 0.0002). Regions of stress were clustered at the staple line near the GOJ, and peak stress was observed there in 67% of models. A uniform greater curvature did not fail or concentrate stress under maximal pressurisation. Geometric variation demonstrated that a larger triangulated apex increased stress by 17% (255 kPa versus 218 kPa), with a 37% increase at the GOJ (203kPA versus 148kPA). A wider incisura reduced stress at the GOJ by 9.9% (128 kPa versus 142 kPa).

Conclusion

High pressure events can occur in the proximal stomach after sleeve gastrectomy. Simulations suggest that these events preferentially concentrate stress forces near the GOJ. This study simulates how high-pressure events could translate stress to the luminal wall and precipitate leak.

Graphical Abstract

Lung Metabolomics Profiling of Congenital Diaphragmatic Hernia in Fetal Rats

Congenital diaphragmatic hernia (CDH) is characterized by the herniation of abdominal contents into the thoracic cavity during the fetal period. This competition for fetal thoracic space results in lung hypoplasia and vascular maldevelopment that can generate severe pulmonary hypertension (PH). The detailed mechanisms of CDH pathogenesis are yet to be understood. Acknowledgment of the lung metabolism during the in-utero CDH development can help to discern the CDH pathophysiology changes. Timed-pregnant dams received nitrofen or vehicle (olive oil) on E9.5 day of gestation. All fetal lungs exposed to nitrofen or vehicle control were harvested at day E21.5 by C-section and processed for metabolomics analysis using nuclear magnetic resonance (NMR) spectroscopy. The three groups analyzed were nitrofen-CDH (NCDH), nitrofen-control (NC), and vehicle control (VC). A total of 64 metabolites were quantified and subjected to statistical analysis. The multivariate analysis identified forty-four metabolites that were statistically different between the three groups. The highest Variable importance in projection (VIP) score (>2) metabolites were lactate, glutamate, and adenosine 5'-triphosphate (ATP). Fetal CDH lungs have changes related to oxidative stress, nucleotide synthesis, amino acid metabolism, glycerophospholipid metabolism, and glucose metabolism. This work provides new insights into the molecular mechanisms behind the CDH pathophysiology and can explore potential novel treatment targets for CDH patients.