Anderson, Bradley J.

AbstractBackgroundNutrient‐mediated release of cholecystokinin and glucagon‐like peptide‐1 (GLP‐1) regulates gastric emptying (GE) via duodenogastric feedback mechanisms; GLP‐1 also regulates postprandial insulin secretion. Some patients with functional upper gastrointestinal symptoms have impaired glucose tolerance during enteral dextrose infusion. Our hypothesis was that variants in CCK, GLP‐1, and TCF7L2 (transcription factor 7‐like 2 locus), which is associated with greatest genetic risk for development of type 2 diabetes mellitus, are associated with GE and independently with glucose tolerance. Our aims were to evaluate the associations between these GE, glucose tolerance, and these single nucleotide polymorphisms (SNPs).MethodsGenetic variants, scintigraphic GE of solids, plasma glucose, insulin, and GLP‐1 during enteral dextrose infusion (75gm over 2 hours) were measured. GE and enteral dextrose infusion were, respectively, evaluated in 44 (27 controls and 17 patients with functional dyspepsia or nausea) and 42 (28 controls, 14 patients) participants; of these, 51 participants consented to assessment of SNPs. Four functional SNPs were studied: rs6923761 and rs1042044 at GLP‐1 receptor, rs7903146 (TCF7L2), and rs1800857 (CCK receptor).Key ResultsGastric emptying was normal in 38, rapid in 4, and delayed in two participants; 38 had normal, and four had impaired glucose tolerance. The T allele at rs7903146 (TCF7L2) was non‐significantly associated (P = .14) with faster GE. The associations between SNPs and demographic variables, GE thalf, glucose tolerance and plasma GLP1 levels were not significant.Conclusions & InferencesThere is a trend toward an association between faster GE and the diabetes‐associated allele at rs7903146 in TCF7L2. However, these SNPs were not associated with plasma glucose or GLP1 concentrations during enteral dextrose infusion.

INTRODUCTION: Double balloon enteroscopy (DBE) is an important tool for evaluation of obscure GI bleeding but is a limited resource given time and expertise required. Patient selection is important to help optimize diagnostic yield and subsequent successful management of small bowel bleeding. To maximize the efficiency of DBE performed, our endoscopy group established a screening protocol (Figure) prior to approval of any procedure. We developed a quality improvement project to assess the efficacy of this screening protocol and to evaluate which components of screening were most predictive for procedural success. METHODS: A retrospective chart review was performed on all patients who underwent anterograde or retrograde double balloon enteroscopy for suspected GI bleeding from January 2016 to December 2017. Our screening protocol was implemented on February 1 st , 2017. Data was obtained on patient demographics, clinical presentation, laboratory evaluation, and prior investigation for bleeding evaluation. Endoscopy outcomes were separated into procedural success, defined as lesion identified, and clinical success, defined as resolution of bleeding. Success rates were compared pre and post intervention. Regression analysis was performed to evaluate which components best predicted a successful procedure. RESULTS: We reviewed 114 DBE procedures in 89 patients, 53.5% male (n = 61) with a mean age of 62.8 + 13.3 years. Of these, 86% (n = 98) were performed prior to initiation of the screening protocol. Overall, there was no significant difference in procedural success pre and post intervention as defined by presence of recurrent bleeding, persistent anemia, or transfusion need (Table 1). On univariate analysis of clinical success, defined as lack of recurrent bleeding, gender, anticoagulation use, and presence of lesion on CE were significant (Table 2). Identification and intervention on a lesion during the balloon endoscopy did not impact future anemia, bleeding, or transfusion requirements. CONCLUSION: The patient screening protocol was successful in decreasing the number of procedures performed but did not improve our lesion detection rate on endoscopy and did not improve clinical outcomes as measured by rebleeding. Patients on anticoagulation and those who had prior lesions identified on capsule endoscopy had higher odds of rebleeding, indicating clinical failure. This data may help modify patient selection to maximize success of DBE procedures in the future.

AbstractAimColon ischaemia (CI) is most commonly an acute and reversible manifestation of a transient, non‐occlusive decrease of blood flow in the colonic microvasculature. Irreversible complications are uncommon and the progression to chronic CI remains controversial. Our objective was to identify cases of chronic CI and assess for distinct clinicopathological features.MethodA retrospective review was performed of CI patients having symptom chronicity of ≥ 1 month and ischaemic histology at our institution from 1994 to 2015. Demographic, clinical, endoscopic, radiological, pathological and outcome variables were abstracted. Histological evaluation was performed by two gastrointestinal pathologists.ResultsFifteen patients (n = 9; 67% men) with a median age of 65 years (range 22–88) were identified. The most common presenting symptoms were diarrhoea and abdominal pain (n = 6, 86%; n = 5, 71%, respectively). The typical endoscopic appearance was segmental ulceration of the sigmoid colon (n = 6, 75%). Vascular imaging showed patent mesenteric vessels in all patients. Histopathological evaluation revealed venous intimal hyperplasia consistent with idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) in eight patients; the remainder showed non‐specific ulceration and fibrosis. Surgical resection was performed in seven IMHMV patients, resulting in symptom resolution. On re‐review of pre‐resection biopsies, all IMHMV patients had characteristic changes of hyperplastic, thick‐walled, hyalinized vessels in the lamina propria.ConclusionsIMHMV is a unique histopathological entity causing chronic CI. The small vessel histological changes in IMHMV are distinctive in colonic resections and undetectable by routine vascular imaging. Preoperative diagnosis of IMHMV is possible with endoscopic biopsy and segmental colon resection is curative.

AbstractBackgroundColonic functions (ie, absorption of fluids and electrolytes, digestion of selected nutrients, harbor for microbes, and elimination of excreta) necessitate complex patterns of storage and transit. Indeed, colonic transit accounts for a major part of the mouth‐to‐anus transit time. Colonic transit assessments are useful for understanding the pathophysiology of disease, the pharmacodynamic effects of new medications and to diagnose slow transit constipation. Currently, radiopaque markers, scintigraphy, and a colonic pH‐pressure capsule are used to measure overall colonic transit. Radioopaque markers, scintigraphy, and the electromagnetic capsule, which is a newer technique, also evaluate regional colonic transit. The pH‐pressure capsule also measures colonic pressures. Magnetic resonance imaging and a radio‐frequency identification‐based device are evolving methods for assessing colonic transit.PurposeThis mini‐review, which accompanies a study evaluating the assessment of colon transit with the electromagnetic capsule, evaluates and compares existing and evolving methods for evaluating colonic transit in humans (Neurogastroenterol Motil. 2018; in press). In addition to overall and regional colonic transit, the electromagnetic capsule evaluates colonic motor patterns without radiation exposure. These patterns are summarized by analyzing the characteristics (ie, distance and velocity) of discrete antegrade and retrograde capsule movements as they travel in the colon. However, the electromagnetic capsule does not measure pressure or colonic wall movement (ie, contractions). The motor patterns identified by this capsule should be compared with motor patterns identified with manometry. The next challenge is to harness different techniques to evaluate the relationships between colonic pressures and transit or, even better, the trifecta of colonic contractions, pressure events, and transit.