Neonatal immune challenge influences the microbiota and behaviour in a sexually dimorphic manner

There is comorbidity between anxiety disorders and gastrointestinal disorders, with both linked to adverse early life events. The microbiome gut-brain-axis, a bidirectional communication system, is plastic throughout the neonatal period and is a possible mediator of this relationship. Here, we used a well-established neonatal rodent immune activation model to investigate the long-term effect of neonatal lipopolysaccharide (LPS) exposure on adult behaviour and the relationship to microbiome composition. Wistar rats were injected with LPS (0.05 mg/kg) or saline (equivolume) on postnatal days 3 and 5. In adulthood, behavioural tests were performed to assess anxiety-like behaviour, and microbiota sequencing was performed on stool samples. There were distinctly different behavioural phenotypes for LPS-exposed males and females. LPS-exposed males displayed typical anxiety-like behaviours with significantly decreased social interaction (F_(1,22) = 7.576, p = 0.009) and increased defecation relative to saline controls (F_(1,23) = 8.623, p = 0.005). LPS-exposed females displayed a different behavioural phenotype with significantly increased social interaction (F_(1,22) = 6.094, p = 0.018), and exploration (F_(1,24) = 6.359, p = 0.015), compared to saline controls. With respect to microbiota profiling data, Bacteroidota was significantly increased for LPS-exposed females (F_(1,14) = 4.931p = 0.035) and Proteobacteria was decreased for LPS-exposed rats of both sexes versus controls (F_(1,30) = 4.923p = 0.035). Furthermore, alterations in predicted functional pathways for neurotransmitters in faeces were observed with a decrease in the relative abundance of D-glutamine and D-glutamate metabolism in LPS exposed females compared to control females (p < 0.05). This suggests that neonatal immune activation alters both later life behaviour and adult gut microbiota in sex-specific ways. These findings highlight the importance of sex in determining the impact of neonatal immune activation on social behaviour and the gut microbiota.

Optimal management of severe symptomatic gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disorder, and empirical proton pump inhibitor (PPI) treatment is often the first step of management; however, up to 40% of patients remain symptomatic despite PPI treatment. Refractory reflux refers to continued symptoms despite an adequate trial of PPI, and management remains challenging. The differential diagnosis is important; other oesophageal (e.g. eosinophilic oesophagitis) and gastroduodenal disorders (e.g. functional dyspepsia) should be ruled out, as this changes management. A combination of clinical assessment, endoscopic evaluation and in selected cases oesophageal function testing can help characterize patients with refractory reflux symptoms into oesophageal phenotypes so appropriate therapy can be more optimally targeted. Medical options then may include adding a H2 receptor antagonist, alginates, baclofen or antidepressant therapy, and there is emerging evidence for bile acid sequestrants and diaphragmatic breathing. The demonstration of a temporal association of symptoms with reflux events on pH-impedance testing (reflux hypersensitivity) serves to focus the management on modulating oesophageal perception and reducing the reflux burden, or identifies those with no obvious pathophysiologic abnormalities (functional heartburn). Anti-reflux surgery based on randomized controlled trial evidence has a role in reflux hypersensitivity or continued pathological acid reflux despite PPI in carefully considered, fully worked up cases that have failed medical therapy; approximately two of three cases will respond but there is a small risk of complications. In patients with persistent volume reflux despite medical therapy, given the lack of alternatives, anti-reflux surgery is a consideration. Promising newer approaches include endoscopic techniques. This review aims to summarize current diagnostic approaches and critically evaluates the evidence for the efficacy of available treatments.

Quantifying Rome symptoms for diagnosis of the irritable bowel syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, diagnosed on symptom-based criteria. Many have reported discrepancies between formal Rome criteria and diagnoses made in clinical practice. The aim of the study was to explore whether a quantitative version of the Rome criteria would better represent a clinical diagnosis of IBS than the current dichotomous criteria for symptom measure.

METHODS

As part of a large, case-control study, participants completed a validated bowel disease questionnaire. Rome criteria were analyzed based on 15 individual symptoms. Penalized logistic regression model with stepwise selection was used to identify significant symptoms of IBS which were independently associated with case-control status.

KEY RESULTS

In cases with a clinical diagnosis of IBS, 347 (70%) met Rome criteria for IBS. Increasing number of Rome symptoms were found related to the odds of being diagnosed with IBS. Nearly half of the Rome-negative case group experienced infrequent symptoms suggesting milder disease. Five of 15 Rome symptoms were associated with predicting case-control status in the final model, with 96% correctly classified among Rome-positive cases, 76% for Rome-negative cases, and 91% for controls.

CONCLUSIONS AND INFERENCES

Irritable bowel syndrome appears to be a spectrum disorder. Quantifying individual symptoms of Rome criteria has greater utility than the current application in representing the degree of IBS affectedness and appears to better reflect a clinical diagnosis of IBS applied by physicians. The use of a quantitative diagnostic Rome "score" may be helpful in clinical practice and research studies to better reflect the degree an individual is affected with IBS.

A pragmatic comparative study of palliative care clinician's reports of the degree of shadowing visible on plain abdominal radiographs

The assessment of constipation symptoms is based on history and physical examination. However, the experience is highly subjective perhaps explaining why palliative medicine doctors continue to use plain abdominal radiographs as part of routine assessment of constipation. Previous studies have demonstrated poor agreement between clinicians with this work in palliative care, limited further by disparity of clinicians' experience and training. The aim of this work was to explore whether there was less variation in the assessments of faecal shadowing made by more experienced clinicians compared to their less experienced colleagues. This pragmatic study was conducted across six palliative care services in Sydney (NSW, Australia). Doctors of varying clinical experience were asked to independently report their opinions of the amount of shadowing seen on 10 plain abdominal radiographs all taken from cancer patients who self-identified themselves as constipated. There were 46 doctors of varying clinical experience who participated including qualified specialists, doctors in specialist training and lastly, doctors in their second- and third post-graduate years. Poor agreement was seen between the faecal shadowing scores allocated by doctors of similar experience and training (Fleiss's kappa (FK): RMO 0.05; registrar 0.06; specialist 0.11). Further, when the levels of agreement between groups were considered, no statistically significant differences were observed. Although the doctors did not agree on the appearance of the film, the majority felt they were able to extrapolate patients' experiences from the radiograph's appearance. As it remains challenging in palliative care to objectively assess and diagnose constipation by history and imaging, uniform and objective assessment and diagnostic criteria are required. It is likely that any agreed criteria will include a combination of imaging and history. The results suggest the use of radiographs alone to diagnose and assess constipation in palliative care represents low value care.

Effects of Antidepressants on Gastric Function in Patients with Functional Dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a highly prevalent functional bowel disorder. The effects of antidepressant therapy (ADTx) on gastric sensorimotor function in FD patients are poorly understood.

AIMS

Determine whether FD and subtypes with abnormalities in gastric function respond differently to ADTx compared to those with normal physiology.

METHODS

This multicenter, prospective trial randomized FD patients to 12 weeks of amitriptyline (AMI; 50 mg), escitalopram (ESC; 10 mg), or matching placebo. Demographics, symptoms, psychological distress, gastric emptying, and satiation were measured. Gastric accommodation (GA) using single-photon emission computed tomography imaging was performed in a subset of patients. An intent to treat analysis included all randomized subjects. The effect of treatment on gastric emptying was assessed using ANCOVA. A post hoc appraisal of the data was performed categorizing patients according to the Rome III subgrouping (PDS and EPS).

RESULTS

In total, 292 subjects were randomized; mean age=44 yrs. 21% had delayed gastric emptying. Neither antidepressant altered gastric emptying, even in those with baseline delayed gastric emptying. GA increased with ADTx (P=0.02). Neither antidepressant affected the maximal-tolerated volume (MTV) of the nutrient drink test although aggregate symptom scores improved compared to placebo (P=0.04). Patients with the combined EPS-PDS subtype (48%) had a lower MTV on the nutrient drink test compared to the EPS group at baseline (P=0.02). Postprandial bloating improved with both AMI (P=0.03) and ESC (P=0.02).

CONCLUSIONS

Amitriptyline (50 mg) improves FD symptoms but does not delay gastric emptying, even in patients with baseline delayed gastric emptying. GA improved with low-dose ADTx; the precise mechanism of action is unknown warranting further study.

Food and functional dyspepsia: a systematic review

BACKGROUND

Functional dyspepsia (FD) is a debilitating functional gastrointestinal disorder characterised by early satiety, post-prandial fullness or epigastric pain related to meals, which affects up to 20% of western populations. A high dietary fat intake has been linked to FD and duodenal eosinophilia has been noted in FD. We hypothesised that an allergen such as wheat is a risk factor for FD and that withdrawal will improve symptoms of FD. We aimed to investigate the relationship between food and functional dyspepsia.

METHODS

Sixteen out of 6451 studies identified in a database search of six databases met the inclusion criteria of studies examining the effect of nutrients, foods and food components in adults with FD or FD symptoms.

RESULTS

Wheat-containing foods were implicated in FD symptom induction in six studies, four of which were not specifically investigating gluten and two that were gluten-specific, with the implementation of a gluten-free diet demonstrating a reduction in symptoms. Dietary fat was associated with FD in all three studies that specifically measured this association. Specific foods reported as inducing symptoms were high in either natural food chemicals, high in fermentable carbohydrates or high in wheat/gluten. Caffeine was associated with FD in four studies, although any association with alcohol was uncertain.

CONCLUSIONS

Wheat and dietary fats may play key roles in the generation of FD symptoms and reduction or withdrawal eased symptoms. Randomised trials investigating the roles of gluten, FODMAPs (fermentable oligosaccharide, disaccharide, monosaccharide and polyols) and high fat ingestion and naturally occurring food chemicals in the generation of functional dyspepsia symptoms are warranted and further investigation of the mechanisms is now required.

Regulation of IL-12p40 by HIF controls Th1/Th17 responses to prevent mucosal inflammation

Intestinal inflammatory lesions are inherently hypoxic, due to increased metabolic demands created by cellular infiltration and proliferation, and reduced oxygen supply due to vascular damage. Hypoxia stabilizes the transcription factor hypoxia-inducible factor-1α (HIF) leading to a coordinated induction of endogenously protective pathways. We identified IL12B as a HIF-regulated gene and aimed to define how the HIF-IL-12p40 axis influenced intestinal inflammation. Intestinal lamina propria lymphocytes (LPL) were characterized in wild-type and IL-12p40^-/- murine colitis treated with vehicle or HIF-stabilizing prolyl-hydroxylase inhibitors (PHDi). IL12B promoter analysis was performed to examine hypoxia-responsive elements. Immunoblot analysis of murine and human LPL supernatants was performed to characterize the HIF/IL-12p40 signaling axis. We observed selective induction of IL-12p40 following PHDi-treatment, concurrent with suppression of Th1 and Th17 responses in murine colitis models. In the absence of IL-12p40, PHDi-treatment was ineffective. Analysis of the IL12B promoter identified canonical HIF-binding sites. HIF stabilization in LPLs resulted in production of IL-12p40 homodimer which was protective against colitis. The selective induction of IL-12p40 by HIF-1α leads to a suppression of mucosal Th1 and Th17 responses. This HIF-IL12p40 axis may represent an endogenously protective mechanism to limit the progression of chronic inflammation, shifting from pro-inflammatory IL-12p70 to an antagonistic IL-12p40 homodimer.

Randomised clinical trial: mesalazine versus placebo in the prevention of diverticulitis recurrence

BACKGROUND

Previous studies have reached conflicting conclusions regarding the efficacy of mesalazine in the prevention of recurrent diverticulitis.

AIM

To investigate the efficacy and safety of mesalazine granules in the prevention of recurrence of diverticulitis after acute uncomplicated diverticulitis.

METHODS

Two phase 3, randomised, placebo-controlled, double-blind multicentre trials (SAG-37 and SAG-51) investigated mesalazine granules in patients with prior episodes (<6 months) of uncomplicated left-sided diverticulitis. Patients were randomised to receive either 3 g mesalazine once daily or placebo (SAG-37, n=345) or to receive either 1.5 g mesalazine once daily, 3 g once daily or placebo for 96 weeks (SAG-51, n=330). The primary endpoint was the proportion of recurrence-free patients during 48 weeks (SAG-37 and SAG-51) or 96 weeks (SAG-51) of treatment.

RESULTS

Mesalazine did not increase the proportion of recurrence-free patients over 48 or 96 weeks compared to placebo. In SAG-37, the proportion of recurrence-free patients during 48 weeks was 67.9% with mesalazine and 74.4% with placebo (P=.226). In SAG-51, the proportion of recurrence-free patients over 48 weeks was 46.0% with 1.5 g mesalazine, 52.0% with 3 g mesalazine and 58.0% with placebo (P=.860 for 3 g mesalazine vs placebo) and over 96 weeks 6.9%, 9.8% and 23.1% respectively (P=.980 for 3 g mesalazine vs placebo). Patients with only one diverticulitis episode in the year prior to study entry had a lower recurrence risk compared to >1 episode. Safety data revealed no new adverse events.

CONCLUSION

Mesalazine was not superior to placebo in preventing recurrence of diverticulitis.

Functional dyspepsia is associated with duodenal eosinophilia in an Australian paediatric cohort

BACKGROUND

The pathophysiology of functional dyspepsia (FD) remains unknown. Duodenal eosinophil infiltration has been reported.

AIM

To assess the association between dyspeptic symptoms and duodenal eosinophilia in children undergoing upper gastrointestinal endoscopy.

METHODS

In this retrospective cohort study, children with normal upper endoscopy and routine histology at a single tertiary paediatric centre between 2010 and 2014 were included. FD was defined as epigastric pain or discomfort >2 months without response to acid suppression. Controls presented with nonerosive reflux disease, dysphagia or rumination syndrome. Intramucosal eosinophil counts were compared between the groups using uni- and multivariate regression analyses.

RESULTS

Thirty-six cases and 36 nonmatched controls were identified. Atopic history (39% vs. 25%) and psychological comorbidity (53% vs. 39%; both P = 0.2) were frequent in cases and controls. Self-reported nausea (64% vs. 17%; P < 0.0001), lethargy (19% vs. 0%; P = 0.005) and family functional gastrointestinal disorder(FGID) (28% vs. 3%; P = 0.003) were more common in cases than controls. Duodenal eosinophil counts [median (IQR): 151 (118-207) vs. 76 (60-106) per mm² ; P < 0.001] were significantly higher in cases than controls with >112 eosinophils per mm² predictive for FD (OR: 33.6, 95% CI: 7.1-159.0; P < 0.001). Duodenal eosinophilia was associated with weight loss (OR: 7.1, 95% CI: 1.1-45.5; P = 0.04).

CONCLUSIONS

Functional dyspepsia in children is strongly associated with duodenal eosinophilia, in the absence of endoscopic or routine histological findings. Frequent atopic and psychological comorbidity illustrate likely multifactorial mechanisms.

Rumination syndrome: pathophysiology, diagnosis, and treatment

BACKGROUND

Rumination syndrome is a functional gastrointestinal disorder characterized by effortless and repetitive regurgitation of recently ingested food from the stomach to the oral cavity followed by either re-swallowing or spitting. Rumination is thought to occur due to a reversal of the esophagogastric pressure gradient. This is achieved by a coordinated abdominothoracic maneuver consisting of a thoracic suction, crural diaphragm relaxation and an increase in intragastric pressure. Careful history is important in the diagnosis of rumination syndrome; patients often report "vomiting" or "reflux" and the diagnosis can therefore be missed. Objective testing is available with high resolution manometry or gastroduodenal manometry. Increase in intra-gastric pressure followed by regurgitation is the most important characteristic to distinguish rumination from other disorders such as gastroesophageal reflux. The mainstay of the treatment of rumination syndrome is behavioral therapy via diaphragmatic breathing in addition to patient education and reassurance.

PURPOSE

The purpose of this review was to critically appraise recent key developments in the pathophysiology, diagnosis and therapy for rumination syndrome. A literature search using OVID (Wolters Kluwer Health, New York, NY, USA) to examine the MEDLINE database its inception until May 2016 was performed using the search terms "rumination syndrome," "biofeedback therapy," and "regurgitation." References lists and personal libraries of the authors were used to identify supplemental information. Articles published in English were reviewed in full text. English abstracts were reviewed for all other languages. Priority was given to evidence obtained from randomized controlled trials when possible.

Irritable bowel syndrome and the perinatal period: lower birth weight increases the risk

BACKGROUND

Early life events have been found to be associated with irritable bowel syndrome (IBS) suggesting a role in development of functional disorders. The study aim was to identify potential perinatal risk factors for adult IBS.

METHODS

Utilizing a population-based nested case-control design, cases who met modified Rome III criteria for IBS and age- and-gender matched controls were identified using responses from prior mailed surveys to a random sample of Olmsted County residents. Medical records of eligible respondents were reviewed for perinatal events of interest. The association of early life events with subsequent case status was assessed using conditional logistic regression.

KEY RESULTS

Of 3 417 respondents, 513 were born in Olmsted County and 108 met criteria for IBS. Due to missing records, 89 pairs were included in the final analyses. Logistic regression revealed only birth weight as a predictor of IBS. Lower birth weight increased the odds for IBS (OR = 1.54 [95% CI = (1.12, 2.08), p = 0.008]). Median birth weight was 3.35 kg (range: 1.96-5.24) and 3.57 kg (range: 2.18-4.59) for cases and controls, respectively. Maternal age, delivery method, and antibiotic exposure were not associated with IBS status but this study was only powered to detect large odds ratios.

CONCLUSIONS AND INFERENCES

Lower birth weight was observed as a risk factor for IBS. It is not clear if in utero developmental delays directly lead to IBS or if low birth weight is a prospective marker for subsequent early life problems leading to IBS.

Evidence that independent gut-to-brain and brain-to-gut pathways operate in the irritable bowel syndrome and functional dyspepsia: a 1-year population-based prospective study

BACKGROUND

Traditionally, functional gastrointestinal disorders (FGIDs) are conceptualised as originating in the brain via stress pathways (brain-to-gut). It is uncertain how many with irritable bowel syndrome (IBS) and functional dyspepsia (FD) have a gut origin of symptoms (gut-to-brain pathway).

AIMS

To determine if there is a distinct brain-to-gut FGID (where psychological symptoms begin first) and separately a distinct gut-to-brain FGID (where gut symptoms start first).

METHODS

A prospective random population sample from Newcastle, Australia who responded to a validated survey in 2012 and completed a 1-year follow-up survey (n = 1900). The surveys contained questions on Rome III IBS and FD and the Hospital Anxiety and Depression Scale.

RESULTS

We found that higher levels of anxiety and depression at baseline were significant predictors of developing IBS (OR = 1.31; 95% CI 1.06-1.61, P = 0.01; OR = 1.54; 95% CI 1.29-1.83, P < 0.001) and FD (OR = 1.28; 95% CI 1.05-1.55, P = 0.01; OR = 1.55, 95% CI 1.32-1.83, P < 0.001), respectively, at the 1-year follow-up. Among those people who did not have elevated levels of anxiety and depression at baseline, subjects at baseline with documented IBS (mean difference 0.34; 95% CI 0.13-0.55, P = 0.002; 0.81; 95% CI 0.47-1.15, P < 0.001) and FD (0.38; 95% CI 0.14-0.63, P = 0.002; 0.92; 95% CI 0.57-1.27, P < 0.001), reported significantly higher levels of anxiety and depression at the 1-year follow-up. We calculated in one-third of individuals a mood disorder precedes FGID but in two-thirds an FGID precedes the mood disorder.

CONCLUSION

While brain-gut pathways are bidirectional, a major subset begin with gut symptoms first and only then psychological distress develops, implicating primary gut mechanisms as drivers of the gut and extra-intestinal features in many cases.

Building a sustainable clinical academic workforce to meet the future healthcare needs of Australia and New Zealand: report from the first summit meeting

The delivery of healthcare that meets the requirements for quality, safety and cost-effectiveness relies on a well-trained medical workforce, including clinical academics whose career includes a specific commitment to research, education and/or leadership. In 2011, the Medical Deans of Australia and New Zealand published a review on the clinical academic workforce and recommended the development of an integrated training pathway for clinical academics. A bi-national Summit on Clinical Academic Training was recently convened to bring together all relevant stakeholders to determine how best to do this. An important part understood the lessons learnt from the UK experience after 10 years since the introduction of an integrated training pathway. The outcome of the summit was to endorse strongly the recommendations of the medical deans. A steering committee has been established to identify further stakeholders, solicit more information from stakeholder organisations, convene a follow-up summit meeting in late 2015, recruit pilot host institutions and engage the government and future funders.

Characterisation of the gastrointestinal mucosa-associated microbiota: a novel technique to prevent cross-contamination during endoscopic procedures

BACKGROUND

The mucosa-associated microbiota appears to be highly relevant to host-microbe interactions in the gastrointestinal (GI) tract. Thus, precise characterisation of the mucosa-associated microbiota may provide important insights for diagnostic and therapeutic development. However, for technical reasons, mucosal biopsies taken during standard endoscopic procedures are potentially contaminated by GI luminal contents.

AIM

To develop and validate a biopsy device that minimises contamination during sampling of the mucosa-associated microbiota.

METHODS

A new, encased biopsy forceps was developed, the Brisbane Aseptic Biopsy Device (BABD). This comprises sterile forceps encased by a sheath with a plug at the tip, allowing targeted, aseptic sampling of the mucosa. Matched duodenal biopsies were obtained using the BABD, standard biopsy forceps, and a sterile brush, from patients undergoing upper GI endoscopy for iron deficiency (n = 6). Total genomic deoxyribonucleic acid (gDNA) was extracted from samples and bacterial 16S rRNA gene libraries sequenced to investigate the mucosa-associated microbiota.

RESULTS

Microbial DNA was recovered from biopsies obtained by the BABD, confirming the presence of a duodenal mucosa-associated microbiota. This microbiota was dominated by the genus Streptococcus, with lower levels of Prevotella, Veillonella and Neisseria. At the individual patient level, substantial differences were observed between matched samples obtained using the different devices. A greater degree of bacterial diversity was observed in samples collected using the standard forceps, indicating the BABD affords collection of samples more representative of the mucosa-associated microbiota, by precluding luminal cross-contamination.

CONCLUSIONS

Cross-contamination can occur when mucosal biopsies are taken during standard endoscopic procedures. Utilising the novel Brisbane Aseptic Biopsy Device can reduce cross-contamination, and it offers improved opportunities to more precisely examine host-mucosa-associated microbiota interactions.

Identification of early environmental risk factors for irritable bowel syndrome and dyspepsia

BACKGROUND

The role of childhood environment including exposure to infection via siblings and pets in irritable bowel syndrome (IBS) and dyspepsia is relatively unknown. We assessed proxy measures of microbial exposure in early childhood to assess if these are associated with IBS and functional dyspepsia in later life.

METHODS

Participants (n = 767, response rate = 53%) were a random population sample from Sydney, Australia who previously responded to a validated survey. IBS and functional dyspepsia were defined using Rome III criteria. Early environmental risk factors assessed included type of birth delivery, premature birth, breastfeeding, bedroom sharing, and pet exposure (the latter two then combined as early hygiene factors) up to 5 years of age. Post infectious IBS (PI-IBS) was assessed by development of IBS following gastroenteritis.

KEY RESULTS

In this sample, in adult life 17% developed IBS (of which 20% had PI-IBS) and 12% functional dyspepsia. Development of IBS was associated with childhood factors-a shorter duration of breastfeeding (odds ratios [OR] = 0.87, 95% CI: 0.78-0.97, p = 0.01), sharing a bedroom (OR = 1.89, 95% CI: 1.73-3.08, p = 0.01), exposure to a herbivore pet (OR = 1.65 (1.10, 2.48), p = 0.02), and hygiene factors (OR = 4.39; 95% CI: 1.89-10.21, p = 0.001). The sole factor associated with functional dyspepsia was exposure to a herbivore pet (1.79; 95% CI: 1.19-2.87, p = 0.02).

CONCLUSIONS & INFERENCES

Childhood environment factors, particularly bedroom sharing and pet exposure, combined with subsequent risk of microbial exposure are a risk factor for IBS in later life. These associations however need confirmation to rule out any risk of a type I error.

Functional dyspepsia and the Rome criteria: a success story

The Rome III criteria for functional dyspepsia (FD), published in 2006, immediately generated controversy but have arguably helped to jump start the field in terms of mechanistic and therapeutic research. One controversy has surrounded the veracity of FD symptom subgroups and their overlap. In clinical practice the overlap of postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) is striking. In this issue, results from Belgium suggest overlap can be reduced by reclassifying those who have postprandial pain or nausea as PDS, and meal-related symptoms predominate in FD. This is consistent with other objective experimental observations. The realization most FD occurs postmeal ingestion is driving a new conceptualization of the syndrome. For example, the observation there is an excess of duodenal eosinophils in PDS has been confirmed, with recent observations implicating increased duodenal permeability and immune activation. The link between PDS and anxiety, not identified in EPS, provides yet further evidence for distinct pathophysiological entities. While symptom-based criteria likely need refinement, the recognition of PDS and EPS has promoted exciting progress.

Differentiation of functional constipation and constipation predominant irritable bowel syndrome based on Rome III criteria: a population-based study

BACKGROUND

While the Rome III classification recognises functional constipation (FC) and constipation predominant IBS (IBS-C) as distinct disorders, recent evidence has suggested that these disorders are difficult to separate in clinical practice.

AIM

To identify whether clinical and lifestyle factors differentiate Rome III-defined IBS-C from FC based on gastrointestinal symptoms and lifestyle characteristics.

METHOD

3260 people randomly selected from the Australian population returned a postal survey. FC and IBS-C were defined according to Rome III. The first model used logistic regression to differentiate IBS-C from FC based on lifestyle, quality-of-life and psychological characteristics. The second approach was data-driven employing latent class analysis (LCA) to identify naturally occurring clusters in the data considering all symptoms involved in the Rome III criteria for IBS-C and FC.

RESULTS

We found n = 206 (6.5%; 95% CI 5.7-7.4%) people met strict Rome III FC whereas n = 109 (3.5%; 95% CI 2.8-4.1%) met strict Rome III IBS-C. The case-control approach indicated that FC patients reported an older age at onset of constipation, were less likely to exercise, had higher mental QoL and less health care seeking than IBS-C. LCA yielded one latent class that was predominantly (75%) FC, while the other class was approximately half IBS-C and half FC. The FC-dominated latent class had clearly lower levels of symptoms used to classify IBS (pain-related symptoms) and was more likely to be male (P = 0.046) but was otherwise similar in distribution of lifestyle factors to the mixed class.

CONCLUSION

The latent class analysis approach suggests a differentiation based more on symptom severity rather than the Rome III view.

Oesophageal narrowing is common and frequently under-appreciated at endoscopy in patients with oesophageal eosinophilia

BACKGROUND

Estimation of the prevalence of oesophageal narrowing and its clinical relevance in patients with oesophageal eosinophilia is probably underestimated by endoscopy.

AIMS

To determine the sensitivity and specificity of oesophagogastroduodenoscopy (EGD) for oesophageal narrowing when compared to a structured oesophagram.

METHODS

We conducted a retrospective chart review at Mayo Clinic, Rochester of adult patients with eosinophilic oesophageal infiltration of >15 eosinophils/hpf with symptomatic dysphagia, who underwent a structured barium oesophagram. The sensitivity and specificity of EGD were evaluated against the gold standard of oesophagram. Demographic and multiple clinical factors were evaluated as potential predictors of oesophageal narrowing.

RESULTS

Of the 58 patients identified, 34 (58.6%) had a narrowed oesophageal diameter (<21 mm). EGD had poor sensitivity (14.7%, 95% CI 5.0-31.1%) for detection of a narrowed oesophagus and only modest specificity (79.2%, 95% CI 57.8-92.9%). Even at a cut-off diameter of EDmax  ≤ 15 mm, EGD had a sensitivity of only 25.0% (95% CI 5.5-57.2%) for narrowed oesophagus. A history of >5 food impaction episodes, endoscopic rings, and female sex were the best predictors of oesophageal narrowing. 86% (6/7) patients with persistent dysphagia despite remission of histological eosinophilia responded to oesophageal dilation all of whom had radiological oesophageal narrowing and 71% of whom had no perceived oesophageal narrowing at EGD.

CONCLUSIONS

Symptomatic oesophageal narrowing identified by barium oesophagography is common and under-recognised at endoscopy in patients with oesophageal eosinophilia.

Increased prevalence of autoimmune diseases in functional gastrointestinal disorders: case-control study of 23471 primary care patients

BACKGROUND

There is increasing evidence that impaired mucosal defence mechanisms are implicated in the pathogenesis of the functional gastrointestinal disorders (FGIDs), allowing inappropriate immune activation.

AIM

To test the hypothesis that an excess of autoimmune disorders among sufferers, using a large primary care database to examine this.

METHODS

Cases were diagnosed with FGIDs - irritable bowel syndrome (IBS), functional dyspepsia (FD), chronic idiopathic constipation (CIC), and multiple FGIDs. Controls were those without FGIDs. Prevalence of autoimmune disorders was compared between cases and controls using odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We included 23,471 patients (mean age 51.4 years, 66.1% female). Prevalence of autoimmune disorders was greater among all FGIDs, compared with controls without. In those with FD (OR 1.35; 95% CI 1.12-1.63), CIC (OR 1.75; 95% CI 1.11-2.75), or multiple FGIDs (OR 1.49; 95% CI 1.25-1.77) this was statistically significant after controlling for age and gender. Rheumatological autoimmune disorders were significantly more frequent in those with FD (OR 1.44; 95% CI 1.15-1.80), CIC (OR 1.84; 95% CI 1.08-3.13), or multiple FGIDs (OR 1.53; 95% CI 1.24-1.88), after controlling for age and gender. However, endocrine autoimmune disorders were no more frequent in those with FGIDs, after controlling for age and gender.

CONCLUSIONS

In a large sample of primary care patients, there was a significantly higher prevalence of autoimmune disorders among those with FD, CIC, or multiple FGIDs not explained by differences in age or gender. We were unable to control for concomitant drug use, which may partly explain this association.

The overlap of atopy and functional gastrointestinal disorders among 23,471 patients in primary care

BACKGROUND

Activation of the immune system has been demonstrated in atopy and functional gastrointestinal disorders (FGIDs). Previous data from our group have suggested a connection between immune dysregulation, FGIDs and mood disorders.

AIM

To investigate if these data translate to clinical practice and examine connections from the perspective of FGIDs to determine whether atopy and FGIDs are connected via mood disorders.

METHODS

Evidence of irritable bowel syndrome (IBS), functional dyspepsia (FD) and constipation was sought from the medical records of 30,000 primary care records over a minimum 5 year period. The same records yielded diagnoses of four atopic conditions (asthma, eczema, allergic rhinitis/hay fever and conjunctivitis).

RESULTS

Atopic conditions were found in excess among all FGID groups considered when compared with controls. In the groups with IBS alone (OR = 1.43, 1.29-1.58), FD alone (OR = 1.41, 1.26-1.58) and those with multiple FGIDs (OR = 1.92, 1.75-2.12) there was elevated prevalence of asthma compared with controls without a FGID. Across disorders the excess was generally highest among patients diagnosed with multiple FGIDs (rhinitis/hay fever OR = 3.74, 3.32-4.20; conjunctivitis OR = 3.00, 2.49-3.62) and was only partly explained by a common association between both FGIDs and atopic conditions with mood disorders, although not for every atopic/FGID combination (rhinitis/hay fever OR = 2.60, 2.29-2.96, conjunctivitis OR = 2.34, 1.90-2.87).

CONCLUSIONS

Irritable bowel syndrome, functional dyspepsia and constipation share an association with atopy that is only partly explained via a common connection with mood disorders. These data have important implications for understanding both the pathophysiology of functional gastrointestinal disorders and development of new treatments.

Overdiagnosis of gastro-esophageal reflux disease and underdiagnosis of functional dyspepsia in a USA community

BACKGROUND

There is symptom overlap between gastro-esophageal reflux disease (GERD) and functional dyspepsia (FD). We aimed to test the hypothesis that FD cases are now more likely mislabeled as GERD.

METHODS

In subjects from Olmsted County, MN seen at Mayo Clinic: (i) Investigation of GERD and FD diagnosis rates between 1985 and 2009. (ii) Assessment of survey-based upper gastrointestinal symptoms between 1988 and 2009. (iii) Analysis of patients reporting GERD and/or FD symptoms and subsequently receiving a consistent diagnosis of GERD and/or FD during a medical encounter. (iv) Assess the association between PPI use and GERD and/or FD symptoms and between actual diagnoses received.

KEY RESULTS

(i) Yearly GERD diagnosis rates rose between 1985 and 2009 (325-1866 per 100 000). FD diagnosis rates rose from 45 in 1985, to 964 in 1999 but decreased to 452 per 100 000 in 2009. (ii) Reported GERD symptoms did not significantly change between three survey waves in the years 1988-2009 (p = 0.052), whereas FD symptoms slightly increased (p = 0.01). (iii) 62.9% of subjects reporting GERD symptoms received a GERD diagnosis, however only 12.5% of subjects reporting FD symptoms received a FD diagnosis. (iv) PPI use was associated with documented GERD diagnosis (p < 0.001), however there was no significant association between GERD symptoms and PPI use (p = 0.078).

CONCLUSIONS & INFERENCES

We have found evidence supporting a systematic bias away from diagnosing FD, favoring a GERD diagnosis.

A case-control study of childhood trauma in the development of irritable bowel syndrome

BACKGROUND

The etiology of irritable bowel syndrome (IBS) is not been fully elucidated, but childhood trauma may disturb the brain-gut axis and therefore be important. Thus, we conducted a family based case-control study of IBS cases and their relatives with the aims to (i) determine the frequency of childhood trauma among IBS cases and controls as well as their relatives, and (ii) assess childhood trauma among IBS cases with affected relatives (familial IBS).

METHODS

Outpatients with IBS, matched controls, and their first-degree relatives completed a self-report version of Bremner' Early Trauma Inventory. Percent of cases and controls with a family history were compared and odds ratios were computed using chi-squared test; recurrence risks to relatives were computed using logistic regression and generalized estimating equations.

KEY RESULTS

Data were collected from 409 cases, 415 controls, 825 case relatives, and 921 control relatives. IBS cases had a median age of 50 and 83% were women. Of IBS cases, 74% had experienced any general trauma compared to 59% among controls, yielding an odds ratio of 1.56 (95% CI: 1.13-2.15, p < 0.008). There were no statistical differences between IBS relatives and control relatives with regards to lifetime trauma.

CONCLUSIONS & INFERENCES

IBS is associated with childhood trauma, and these traumas often occur prior to onset of IBS symptoms. This provides further insight into how traumatic childhood events are associated with development of adult IBS.

Review article: Associations between Helicobacter pylori and obesity--an ecological study

BACKGROUND

There is emerging debate over the effect of Helicobacter pylori infection on body mass index (BMI). A recent study demonstrated that individuals who underwent H. pylori eradication developed significant weight gain as compared to subjects with untreated H. pylori colonisation.

AIM

To elucidate the association between H. pylori colonisation and the prevalence of overweight and obesity in developed countries.

METHODS

The literature was searched for publications reporting data on H. pylori prevalence rates and obesity prevalence rates. Studies selected reported H. pylori prevalence in random population samples with sample sizes of more than 100 subjects in developed countries (GDP >25,000 US$/person/year). Corresponding BMI distributions for corresponding countries and regions were identified. Nonparametric tests were used to compare the association between H. pylori and overweight and obesity rates.

RESULTS

Forty-nine studies with data from 10 European countries, Japan, the US and Australia were identified. The mean H. pylori rate was 44.1% (range 17-75%), the mean rates for obesity and overweight were 46.6 (± 16)% and 14.2 (± 8.9)%. The rate of obesity and overweight were inversely and significantly (r = 0.29, P < 0.001) correlated with the prevalence of H. pylori infection.

CONCLUSIONS

There is an inverse correlation between H. pylori prevalence and rate of overweight/obesity in countries of the developed world. Thus, the gradual decrease of the H. pylori colonisation that has been observed in recent decades (or factors associated with decrease of) could be causally related to the obesity endemic observed in the Western world.

Risk of developing colorectal cancer and benign colorectal neoplasm in patients with chronic constipation

BACKGROUND

Chronic constipation (CC) is a highly prevalent health problem, potentially associated with increased risk of colorectal cancer (CRCancer).

AIM

To investigate the association between CC, its severity, and CRCancer by estimating the relative risk of developing CRCancer and benign colorectal neoplasm (BCN) among severity-stratified patients with and without CC.

METHODS

Chronic constipation patients from a large retrospective US claims database were matched 1:3 with CC-free controls by demographic characteristics. CRCancer and BCN prevalence were measured over 1 year. In pre-index CRCancer- and BCN-free patients, incidence rate ratios (IRRs) of new CRCancer and BCN were calculated. Multivariate regression models adjusted for comorbidities and family history. CC patients' disease severity was rated based on CC-related resource use. IRRs for new CRCancer and BCN were estimated for CC severity groups and controls.

RESULTS

Chronic constipation (N = 28,854) and CC-free (N = 86,562) patients had mean age 61.9 years; 66.7% were female. One-year CRCancer prevalence was 2.7% and 1.7%, and BCN prevalence was 24.8% and 11.9% for CC and CC-free patients, respectively. Adjusted IRRs between CC and CC-free patients were 1.59 [95% confidence interval (CI): 1.43-1.78] and 2.60 [95% CI: 1.51-2.70] for CRCancer and BCN, respectively. Patients with severe and very severe CC had significantly greater incidence of CRCancer and BCN. At ≥ 2 and ≥ 5 years of observation, CRCancer and BCN incidence remained consistently and significantly higher for CC patients.

CONCLUSIONS

Patients with chronic constipation are associated with significantly higher prevalence and incidence of colorectal cancer and benign colorectal neoplasm than matched chronic constipation-free patients. These risks increase with the severity of chronic constipation.

Review article: bacteria and pathogenesis of disease in the upper gastrointestinal tract--beyond the era of Helicobacter pylori

BACKGROUND

Study of the upper gastrointestinal microbiome has shown that other bacteria besides Helicobacter pylori flourish despite the hostile environment. Whilst H. pylori is the most studied bacteria in this region with a defined role in inflammation and neoplasia, it is apparent that other bacteria may contribute to UGI disease.

AIM

To review current knowledge of bacteria inhabiting the oesophagus, stomach and duodenum.

METHODS

Published studies on the upper gastrointestinal microbiome (extracted from PubMed during the last 20 years).

RESULTS

The stomach is a hostile environment for bacteria; however, recent studies categorising the microbiota have shown surprising results. Helicobacter pylori has been intensively studied since 1984 and recent sequencing analysis of other gastric microbiota shows that H. pylori is not alone. Composition can be influenced by acid suppression, gastritis and abundance of H. pylori. Eradication of H. pylori, whilst decreasing gastric cancer is associated with an increase in asthma, reflux and obesity. A future approach may be to selectively eradicate bacteria which predispose to inflammation and cancer as opposed to a comprehensive knockout policy. In the oesophagus, viridans streptococci are the most common bacteria influenced by both oral and gastric bacteria. Oesophagitis and Barrett's oesophagus are characterised by a significant decrease in Gram-positive bacteria and an increase in Gram-negative bacteria. An inverse association of H. pylori and oesophageal adenocarcinoma is described. The duodenal microbiome has been shown to influence small intestinal bacterial overgrowth, irritable bowel syndrome and coeliac disease. The numbers of bacteria recoverable by culture are variable in the stomach mucosa and gastric juice, typically 10(2) -10(4) colony-forming units (CFU)/g or mL and in the oesophagus, up to 10(4) bacteria per mm(2) mucosal surface. In the small bowel, in health, 10(3) CFU/mL are normal.

CONCLUSION

This review highlights current knowledge of upper gastrointestinal bacteria and associations with disease.

A biomarker panel and psychological morbidity differentiates the irritable bowel syndrome from health and provides novel pathophysiological leads

BACKGROUNDS

The development of a reliable biomarker for irritable bowel syndrome (IBS) remains one of the major aims of research in functional gastrointestinal disorders (FGIDs) and is complicated by the absence of a perfect reference standard. Previous efforts based on genetic and immune markers have showed promise, but have not been robust.

AIM

To evaluate an extensive panel of gene expression and serology markers combined with psychological measures in differentiating IBS from health and between subtypes of IBS.

METHODS

Of subjects eligible for analysis (N = 244), 168 met criteria for IBS (60 IBS-C, 57 IBS-D and 51 mixed), while 76 were free of any FGID. A total of 34 markers were selected based on pathways implicated in pathophysiology of IBS or whole human genome screening. Psychological measures were recorded that covered anxiety, depression and somatisation. Models differentiating disease and health were based on unconditional logistic regression and performance assessed through area under the receiver-operator characteristic curve (AUC), sensitivity and specificity.

RESULTS

The performance of a combination of 34 markers was good in differentiating IBS from health (AUC = 0.81) and was improved considerably with the addition of four psychological markers (combined AUC = 0.93). Of the 34 markers considered, discrimination was derived largely from a small subset. Good discrimination was also obtained between IBS subtypes with the best being observed for IBS-C vs. IBS-D (AUC = 0.92); however, psychological variables provided almost no incremental discrimination subtypes over biological markers (combined AUC = 0.94).

CONCLUSIONS

A combination of gene expression and serological markers in combination with psychological measures shows exciting progress towards a diagnostic test for IBS compared with healthy subjects, and to discriminate IBS-C from IBS-D.

Novel partial 5HT3 agonist pumosetrag reduces acid reflux events in uninvestigated GERD patients after a standard refluxogenic meal: a randomized, double-blind, placebo-controlled pharmacodynamic study

BACKGROUND

Low basal lower esophageal sphincter (LES) pressure and transient LES relaxations are major causes of gastroesophageal reflux disease (GERD). Pumosetrag, a novel selective partial 5HT3 receptor agonist, showed a promising effect on reducing reflux events in health. We aimed to evaluate the effect of pumosetrag on changes in reflux episodes, lower esophageal sphincter pressure (LESP), and specific symptoms in patients with GERD receiving a refluxogenic meal.

METHODS

Patients with GERD, who developed heartburn and/or regurgitation after ingestion of a refluxogenic meal, were randomized to 1 of 3 dose levels of pumosetrag (0.2, 0.5, or 0.8 mg) or placebo. Before and after 7 days of treatment, patients underwent manometry, intraesophageal multichannel, intraluminal impedance and pH after a standard refluxogenic meal.

KEY RESULTS

A total of 223 patients with GERD [125 (56%) women, mean (SD) age = 36 (12) years] were enrolled. No overall treatment effects were detected for the total number of reflux episodes (acidic and weakly acidic) (p > 0.5); however, significant treatment effects (p < 0.05) on the number of acid reflux episodes were observed with lower values on pumosetrag 0.2 mg (10.8 ± 1.1), 0.5 mg (9.5 ± 1.1), and 0.8 mg (9.9 ± 1.1) compared with placebo (13.3 ± 1.1). Significant treatment effects (p < 0.05) were also observed for the percentage of time pH was <4, with less time for pumosetrag at 0.5 mg (10%) and 0.8 mg (10%) compared with placebo (16%).

CONCLUSIONS & INFERENCES

In GERD, the partial 5HT3 agonist pumosetrag significantly reduced the rate of acid reflux events but did not result in a significant change in LESP or symptomatic improvement over a 1-week treatment period.

The outcome of patients with oesophageal eosinophilic infiltration after an eight-week trial of a proton pump inhibitor

BACKGROUND

Current diagnostic guidelines recommend that eosinophilic oesophagitis (EoE) should be diagnosed only after GERD is excluded by a lack of response to a trial of acid suppression. There is limited information available providing outcome data about the effectiveness of this approach.

AIM

To examine the impact of double-dose proton pump inhibitor (PPI) therapy on symptoms, endoscopic and histological features in patients with documented oesophageal eosinophilia consistent with EoE (≥15 eosinophils/high-power field).

METHODS

Sixty consecutive symptomatic patients with documented oesophageal eosinophilia received open-label omeprazole 20 mg orally twice daily before meals for 8 weeks. Clinical, endoscopic and histological (resolution: 0-5 eosinophils/HPF, partial improvement: 5-14 eosinophils/HPF), or no improvement: (≥15 eosinophils/HPF) evaluation was repeated at the end of this period. An expert GI pathologist, unaware of the study aims, reviewed all slides.

RESULTS

Clinical improvement occurred in 43 (71.6%), endoscopic signs were reduced in 34 (61.8%) and normalised in 12 (21.8%), and histologically, 34 (56.6%) improved, while 15 (25%) obtained complete resolution. Overall, 22 patients (36.7%) obtained both complete clinical and histological remission.

CONCLUSIONS

More than 50% of patients with documented oesophageal eosinophilic infiltration in the EoE range improved when treated with a double-dose PPI trial for 8 weeks. These findings support the published guidelines recommending a PPI trial prior to diagnosing EoE, and confirm the existence of an eosinophilic oesophageal infiltrationPPI-responsive population.

Abdominal pain is associated with anxiety and depression scores in a sample of the general adult population with no signs of organic gastrointestinal disease

BACKGROUND

Abdominal pain is common in the community, but only a subset meet diagnostic criteria for irritable bowel syndrome (IBS). Although anxiety and depression have been linked to IBS, the role of mood disturbances in the remainder with symptoms remains unclear. We aimed to study the associations between abdominal pain, anxiety, depression, and quality of life in the general population who were free of organic colonic disease by colonoscopy.

METHODS

Two hundred and seventy-two randomly selected subjects from the general population, mean age 54 years (27-71), were clinically evaluated, had a colonoscopy and laboratory investigations to exclude organic gastrointestinal (GI) disease. All subjects completed GI symptom diaries for 1 week, the Rome II modular questionnaire, the Hospital Anxiety and Depression Scale, and Short Form 36.

KEY RESULTS

Twenty-two subjects were excluded due to organic disease; 1532 daily symptom records were available for analysis in the remainder. Thirty-four percent (n = 83) recorded at least one episode of abdominal pain on the diary. Twelve percent fulfilled Rome II criteria for IBS. Both anxiety and depression scores were higher in subjects who reported abdominal pain vs those who did not (P < 0.0005 and P < 0.0005). Anxiety and depression scores independently from IBS diagnosis (Rome II) predicted pain reporting and also correlated positively with pain burden. Quality of life scores were generally lower in subjects with abdominal pain.

CONCLUSIONS & INFERENCES

Anxiety and depression are linked to functional abdominal pain, not only in subjects with IBS but also in otherwise healthy people with milder, subtle GI symptoms.

Functional dyspepsia: the economic impact to patients

BACKGROUND

Although highly prevalent, little is known about the economic impact of functional dyspepsia (FD).

AIMS

To quantify FD patients' health care utilisation patterns and to estimate direct and indirect costs of FD to patients.

METHODS

ICD-9 codes identified adult patients with dyspepsia. A validated questionnaire was mailed to patients who met Rome III criteria for FD.

RESULTS

Three hundred and fifty-five patients met all inclusion criteria. The response rate was 63%. The respondents' mean age was 50 (14) years; 75% were women; 52% of respondents rated their FD as moderate. Patients reported 3 visits (mean) to their PCP over 12 months; 75% reported having blood work, 92% an EGD, 59% an ultrasound and 40% a CT scan. The direct cost of testing using Medicare reimbursement rates per patient was $582. To treat FD symptoms, 89% tried dietary changes, 89% over-the-counter medications, 87% prescription medications and 25% alternative therapies. Mean patient expenditure over the last year was $246 for OTC medications (range $0-12,000), $290 for co-payments (range $0-9,000) and $110 for alternative treatments (range $0-3,741). Total mean direct cost yearly to patients was $699. In the 7 days prior to completing the questionnaire, respondents reported a mean of 1.4 h absence from work. Extrapolating the results to the US population, we conservatively calculate the costs of FD were $18.4 billion in 2009.

CONCLUSIONS

Functional dyspepsia patients incur significant direct and indirect costs and work productivity is impaired by dyspeptic symptoms.

Psychological impact and risk factors associated with new onset fecal incontinence

OBJECTIVES

We aim to evaluate the psychological impact and risk factors associated with new onset FI over 12 years in adults over 18 years for the first time in a population-based study.

METHODS

Participants (n = 1775) were a random population sample from Penrith, Australia who responded to a survey in 1997 and completed a 12-year follow-up survey (response rate = 60%). FI was defined as having leakage of stool over the past 12 months. The original and follow-up surveys contained valid questions on demographic, gastrointestinal and psychological symptoms.

RESULTS

114 (11.4%) reported new onset FI at the 12 year follow-up. People who reported FI at the 12 year follow-up were significantly more anxious and depressed. In terms of baseline risk factors only bloating (OR = 1.3; 95%CI 1.0-1.6, P = 0.026) was an independent predictor of developing new onset FI. However, current bowel symptoms measured at follow-up including less likelihood of <3 bowel motions a week, increased urgency and mucus were independently associated with having FI at follow-up.

CONCLUSION

FI is associated with anxiety and depression. Baseline GI symptoms do not appear to be as important as current bowel symptoms in determining who develops FI.

Endoscopic full-thickness biopsy of the gastric wall with defect closure by using an endoscopic suturing device: survival porcine study

BACKGROUND

The pathogenesis of several common gastric motility diseases and functional GI disorders remains essentially unexplained. Gastric wall biopsies that include the muscularis propria to evaluate the enteric nervous system, interstitial cells of Cajal, and immune cells can provide important insights for our understanding of the etiology of these disorders.

OBJECTIVES

To determine the technical feasibility, reproducibility, and safety of performing a full-thickness gastric biopsy (FTGB) by using a submucosal endoscopy with mucosal flap (SEMF) technique; the technical feasibility, reproducibility, and safety of tissue closure by using an endoscopic suturing device; the ability to identify myenteric ganglia in resected specimens; and the long-term safety.

DESIGN

Single center, preclinical survival study.

SETTING

Animal research laboratory, developmental endoscopy unit.

SUBJECTS

Twelve domestic pigs.

INTERVENTIONS

Animals underwent an SEMF procedure with gastric muscularis propria resection. The resultant offset mucosal entry site was closed by using an endoscopic suturing device. Animals were kept alive for 2 weeks.

MAIN OUTCOME MEASUREMENTS

The technical feasibility, reproducibility, and safety of the procedure; the clinical course of the animals; the histological and immunochemical evaluation of the resected specimen to determine whether myenteric ganglia were present in the sample.

RESULTS

FTGB was performed by using the SEMF technique in all 12 animals. The offset mucosal entry site was successfully closed by using the suturing device in all animals. The mean resected tissue specimen size was 11 mm. Mean total procedure time was 61 minutes with 2 to 4 interrupted sutures placed per animal. Histology showed muscularis propria and serosa, confirming full-thickness resections in all animals. Myenteric ganglia were visualized in 11 of 12 animals. The clinical course was uneventful. Repeat endoscopy and necropsy at 2 weeks showed absence of ulceration at both the mucosal entry sites and overlying the more distal muscularis propria resection sites. There was complete healing of the serosa in all animals with minimal single-band adhesions in 5 of 12 animals. Retained sutures were present in 10 of 12 animals.

LIMITATIONS

Animal experiment.

CONCLUSIONS

FTGB by using the SEMF technique and an endoscopic suturing device is technically feasible, reproducible, and safe. Larger tissue specimens will allow improved analysis of multiple cell types.