Publications by authors named "Geoffrey Hebbard"

25 Publications

  • Page 1 of 1

Diagnostic Criteria for Gastro-esophageal Reflux Following Sleeve Gastrectomy.

Obes Surg 2021 Apr 25;31(4):1464-1474. Epub 2021 Jan 25.

Department of Surgery, Central Clinical School, Monash University, Level 6, Alfred Centre, 99 Commercial Rd, Melbourne, VIC, 3004, Australia.

Background: Gastro-esophageal reflux disease (GERD) post-sleeve gastrectomy (SG) is a controversial issue and diagnostic dilemma. Strong heterogeneity exists in the assessment of reflux post-SG, and better diagnostic tools are needed to characterize symptomatic reflux. We aimed to determine the discriminant factors of symptomatic reflux and establish diagnostic thresholds for GERD following SG.

Materials And Methods: Patients post-SG were categorized into asymptomatic and symptomatic cohorts and completed validated symptom questionnaires. All patients underwent stationary esophageal manometry and 24-h ambulatory pH monitoring. Univariate and multivariate analyses were conducted to determine the strongest discriminant factors for GERD.

Results: Baseline characteristics of the asymptomatic cohort (n = 48) and symptomatic cohort (n = 76) were comparable. The median post-operative duration was 7.3 (14.1) vs 7.5 (10.7) months (p = 0.825). The symptomatic cohort was more female predominant (90.8 vs 72.9%, p = 0.008). Reflux scores were significantly higher in the symptomatic group (36.0 vs 10.5, p = 0.003). Stationary manometry parameters were similar, including hiatus hernia prevalence and impaired esophageal motility. The symptomatic cohort had significantly higher total acid exposure, especially while supine (11.3% vs 0.6%, p < 0.001). Univariate and multivariate regressions delineated reflux score and supine acid exposure as discriminant factors for symptomatic reflux. The thresholds for distinguishing symptomatic reflux are as follows: reflux score of 11.5 (sensitivity 84.0%, specificity 68.2%) and supine acid exposure of 2.65% (sensitivity 67.1%, specificity 70.8%).

Conclusion: A reflux score of 11.5 or more or supine acid exposure of 2.65% or more should be considered diagnostic in defining symptomatic reflux following SG.
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http://dx.doi.org/10.1007/s11695-020-05152-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8012318PMC
April 2021

Esophageal motility disorders on high-resolution manometry: Chicago classification version 4.0.

Neurogastroenterol Motil 2021 01;33(1):e14058

Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.

Chicago Classification v4.0 (CCv4.0) is the updated classification scheme for esophageal motility disorders using metrics from high-resolution manometry (HRM). Fifty-two diverse international experts separated into seven working subgroups utilized formal validated methodologies over two-years to develop CCv4.0. Key updates in CCv.4.0 consist of a more rigorous and expansive HRM protocol that incorporates supine and upright test positions as well as provocative testing, a refined definition of esophagogastric junction (EGJ) outflow obstruction (EGJOO), more stringent diagnostic criteria for ineffective esophageal motility and description of baseline EGJ metrics. Further, the CCv4.0 sought to define motility disorder diagnoses as conclusive and inconclusive based on associated symptoms, and findings on provocative testing as well as supportive testing with barium esophagram with tablet and/or functional lumen imaging probe. These changes attempt to minimize ambiguity in prior iterations of Chicago Classification and provide more standardized and rigorous criteria for patterns of disorders of peristalsis and obstruction at the EGJ.
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http://dx.doi.org/10.1111/nmo.14058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8034247PMC
January 2021

Measurement of fasted state gastric antral motility before and after a standard bioavailability and bioequivalence 240 mL drink of water: Validation of MRI method against concomitant perfused manometry in healthy participants.

PLoS One 2020 11;15(11):e0241441. Epub 2020 Nov 11.

Nottigham Digestive Diseases Centre and NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, United Kingdom.

Objective: The gastrointestinal environment in which drug products need to disintegrate before the drug can dissolve and be absorbed has not been studied in detail due to limitations, especially invasiveness of existing techniques. Minimal in vivo data is available on undisturbed gastrointestinal motility to improve relevance of predictive dissolution models and in silico tools such as physiologically-based pharmacokinetic models. Recent advances in magnetic resonance imaging methods could provide novel data and insights that can be used as a reference to validate and, if necessary, optimize these models. The conventional method for measuring gastrointestinal motility is via a manometric technique involving intubation. Nevertheless, it is feasible to measure gastrointestinal motility with magnetic resonance imaging. The aim of this study was is to develop and validate a magnetic resonance imaging method using the most recent semi-automated analysis method against concomitant perfused manometry method.

Material And Methods: Eighteen healthy fasted participants were recruited for this study. The participants were intubated with a water-perfused manometry catheter. Subsequently, stomach motility was assessed by cine-MRI acquired at intervals, of 3.5min sets, at coronal oblique planes through the abdomen and by simultaneous water perfused manometry, before and after administration of a standard bioavailability / bioequivalence 8 ounces (~240mL) drink of water. The magnetic resonance imaging motility images were analysed using Spatio-Temporal Motility analysis STMM techniques. The area under the curve of the gastric motility contractions was calculated for each set and compared between techniques. The study visit was then repeated one week later.

Results: Data from 15 participants was analysed. There was a good correlation between the MRI antral motility plots area under the curve and corresponding perfused manometry motility area under the curve (r = 0.860) during both antral contractions and quiescence.

Conclusion: Non-invasive dynamic magnetic resonance imaging of gastric antral motility coupled with recently developed, semi-automated magnetic resonance imaging data processing techniques correlated well with simultaneous, 'gold standard' water perfused manometry. This will be particularly helpful for research purposes related to oral absorption where the absorption of a drug is highly depending on the underlying gastrointestinal processes such as gastric emptying, gastrointestinal motility and availability of residual fluid volumes.

Clinical Trial: This trial was registered at ClinicalTrials.gov as NCT03191045.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241441PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7657519PMC
December 2020

Unusual radiological sign in a gentleman with recurrent dysphagia.

Frontline Gastroenterol 2020 Oct 24;11(6):499-500. Epub 2020 Apr 24.

Division of Gastroenterology, Royal Melbourne Hospital, Melbourne, Victoria, Australia.

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http://dx.doi.org/10.1136/flgastro-2020-101440DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7569526PMC
October 2020

Mechanisms of Esophageal and Gastric Transit Following Sleeve Gastrectomy.

Obes Surg 2021 Feb 22;31(2):725-737. Epub 2020 Sep 22.

Department of Surgery, Central Clinical School, Monash University, 99 Commercial Road, Melbourne, VIC, 3004, Australia.

Purpose: Sleeve gastrectomy (SG) patients have substantially altered anatomy. The mechanism of rapid gastric emptying and the role of esophageal contractile function in esophago-gastric transit has not been defined. We aimed to determine the mechanisms of esophago-gastric transit and role of esophageal function following sleeve gastrectomy.

Methods: Prospective study of twenty-six asymptomatic participants post SG underwent nuclear scintigraphy and high-resolution manometry. Fourteen had semi-solid stress barium to model the emptying process. Concurrent video fluoroscopy and manometry were performed on 7 participants.

Results: Demographic data are as follows: age 45.3 ± 15.0 years, 73.1% female, excess weight loss 62.2 ± 28.1% at 8 months. Scintigraphy showed rapid gastric emptying (24.4 ± 11.4 vs. 75.80 ± 45.19 min in control, p < 0.001) with 35.24 ± 17.12% of bolus transited into small bowel on initial frame. Triggered deglutitive reflux was common (54.4% vs. 18.2%, p = 0.017). Stress barium delineated separate vertical and antral gastric compartments with cyclical emptying of 8 stages, including reflux-induced repeated esophageal peristalsis. During manometry, ramping effects were noted, with sequential swallows producing sustained isobaric pressurizations in proximal stomach (33.6 ± 29.5 mmHg). Video fluoroscopy showed individual esophageal peristalsis generating pressurizations at 5.0 ± 1.4 cm below lower esophageal sphincter (LES), at amplitude of 31.6 ± 13.1 mmHg, associated with intragastric transit. Pressurizations were sustained for 17.3 ± 8.2 s, similar to the prolonged LES contraction (18.5 ± 9.0 s, p = 0.355).

Conclusions: Repeated esophageal peristaltic contractions induced isobaric pressurization of proximal stomach, thus providing the drive to pressurize and empty the vertical compartment of the gastric sleeve. Transit following SG appeared to be esophageal-mediated and followed a distinct cycle with strong associations with reflux.
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http://dx.doi.org/10.1007/s11695-020-04988-1DOI Listing
February 2021

eHealth Technologies for Screening, Diagnosis, and Management of Viral Hepatitis: A Systematic Review.

Clin Gastroenterol Hepatol 2020 Sep 5. Epub 2020 Sep 5.

University of Melbourne, Department of Medicine and Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia; Metabolic Diseases Unit, Royal Melbourne Hospital, Melbourne, Australia; Business Intelligence Unit, Royal Melbourne Hospital, Melbourne, Australia.

Background & Aims: Chronic viral hepatitis is a leading cause of worldwide liver-related morbidity and mortality, despite the availability of effective treatments that reduce or prevent complications in most patients. Electronic-health (eHealth) technologies have potential to intervene along the whole cascade of care. We aimed to summarize available literature on eHealth interventions with respect to conventional screening, diagnostic and treatment outcomes in chronic hepatitis B (HBV) and hepatitis C (HCV).

Methods: We systematically reviewed MEDLINE, EMBASE, Cochrane Library and international conference abstracts, including studies published from 2009 - 2020. Overall 80 studies were included, covering electronic medical record (EMR) interventions (n=39), telemedicine (n=20), mHealth (n=5), devices (n=4), clinical decision support (n=3), web-based (n=5), social media (n=1) and electronic communication (n=3).

Results: Compared to standard care, EMR alerts increase screening rates in eligible populations including birth cohort screening in HCV, universal HCV screening in Emergency Departments, ethnic groups with high HBV prevalence, and HBV screening prior to immunosuppression. Direct messaging alerts to providers and automated testing may have a greater effect. No significant difference was found in sustained virological response outcomes between telemedicine and face-to-face management for community, rural and prison cohorts in HCV in the direct acting antiviral era of treatment, with higher patient satisfaction in telemedicine groups.

Conclusions: EMR alerts significantly increase screening rates in eligible cohorts in both chronic HBV and HCV. Telemedicine is equally efficacious to face-to-face care in HCV treatment. Other eHealth technologies show promise; however rigorous studies are lacking.
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http://dx.doi.org/10.1016/j.cgh.2020.09.011DOI Listing
September 2020

Chronic constipation and abdominal pain: Independent or closely interrelated symptoms?

J Gastroenterol Hepatol 2020 Aug 21;35(8):1294-1301. Epub 2020 Jan 21.

Department of Gastroenterology, Alfred Health and Monash University, Melbourne, Victoria, Australia.

Constipation is both a symptom and a disorder, seen in both functional constipation and irritable bowel syndrome with constipation predominance (IBS-C). Despite the Rome IV criteria distinguishing between these conditions, they share many therapeutic approaches. This review aims to explore the relationship between constipation and abdominal pain and assess the evidence surrounding whether laxation improves abdominal pain and whether such a response to laxation differs between IBS-C and functional constipation. In patients with functional constipation, increasing frequency of bowel motions by laxatives regardless of mechanism of action is associated with reductions in the severity of abdominal pain, supporting the role of constipation as a contributor to abdominal discomfort. In patients with IBS-C, evidence from systematic reviews indicates that abdominal pain is driven by factors additional to constipation alone and that visceral analgesic modulation is also needed to optimize pain. Changing definitions of IBS-C and heterogeneity in clinical trial design including endpoints have raised uncertainty about the comparative ability of older laxatives without known neuromodulatory effects to improve chronic abdominal pain compared with new secretagogues and prokinetics for the management of IBS-C. While it is known that abdominal pain is associated with constipation and laxation contributes to relief of that pain, it remains unproven whether proposed visceral analgesic properties of new laxatives provide greater pain relief than laxation alone. However, it is likely that the response to laxation in IBS-C is only part of the puzzle.
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http://dx.doi.org/10.1111/jgh.14970DOI Listing
August 2020

Urinary and faecal incontinence: psychological factors and management recommendations.

N Z Med J 2019 10 4;132(1503):25-33. Epub 2019 Oct 4.

Clinical Psychologist; Senior Lecturer, Department of Psychological Sciences, Swinburne University of Technology, Melbourne, Australia; Department of Medicine, The University of Melbourne, Melbourne, Australia; Department of Gastroenterology and Hepatology, Royal Melbourne Hospital, Melbourne, Australia; Department of Psychiatry, St Vincent's Hospital, Melbourne, Australia.

Background: Urinary and faecal incontinence substantially impacts upon physical health and is associated with significant psychological distress and reduced quality of life. Due to stigma and embarrassment, many patients do not present for management of their incontinence.

Aim: The objective of this article is to summarise the forms and causes of urinary and faecal incontinence, highlight the psychological mechanisms and psychopathology associated with incontinence, and provide management recommendations.

Conclusion: Urinary and faecal incontinence can have a significant impact on an individual's psychological wellbeing and quality of life. Psychological factors may either contribute to or arise from incontinence and should be addressed as part of the overall management plan.
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October 2019

Outcome of hospital outpatient treatment of functional gastrointestinal disorders.

Intern Med J 2019 Feb;49(2):225-231

Department of Gastroenterology, St Vincent's Hospital, Melbourne, Victoria, Australia.

Background: Functional gastrointestinal disorders (FGID) are the commonest conditions observed in gastrointestinal (GI) practice, yet the outcomes of their outpatient care are not known.

Aim: To evaluate the outcome for patients with FGID attending a specialist GI clinic.

Methods: Consecutive, newly referred patients with a FGID attending a specialist GI clinic in a tertiary hospital, over a 1-year period were reviewed and then completed a phone survey to assess current symptoms.

Results: Of 102 patients, 57% had irritable bowel syndrome, 28% functional dyspepsia and 15% other functional disorders. At interview, a median of 402 days after the last consultation 38% expressed symptom improvement, but 64% remained concerned about their condition despite 62% having been reassured. After treatment, 50% of employed patients took time off work because of gut symptoms. Functional dyspepsia patients were less likely to be symptomatically improved than other FGID (21% vs 45%, P = 0.02). Patients given a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols were more likely than others to achieve symptom improvement (53% vs 31%, P = 0.03); PPI-treated patients were less likely to experience improvement (22% vs 44%, P = 0.05); other treatments did not predict outcome. Number of visits, seniority of clinician, duration of care and comorbidities did not predict outcome.

Conclusion: One year after attending a specialist GI clinic a minority of patients with FGID were symptomatically improved. Failure to benefit by many patients may relate to the nature of patients and conditions being treated or the limited nature and range of treatments offered. Different models of care, including more diverse multidisciplinary models, should be explored.
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http://dx.doi.org/10.1111/imj.14067DOI Listing
February 2019

Examining maintenance care following infliximab salvage therapy for acute severe ulcerative colitis.

J Gastroenterol Hepatol 2018 Jan;33(1):226-231

Department of Gastroenterology, Austin Health, Melbourne, Australia.

Background And Aim: Data supporting the optimal maintenance drug therapy and strategy to monitor ongoing response following successful infliximab (IFX) induction, for acute severe ulcerative colitis (ASUC), are limited. We aimed to evaluate maintenance and monitoring strategies employed in patients post-IFX induction therapy.

Methods: Patients in six Australian tertiary centers treated with IFX for steroid-refractory ASUC between April 2014 and May 2015 were identified via hospital IBD and pharmacy databases. Patients were followed up for 1 year with clinical data over 12 months recorded. Analysis was limited to patient outcomes beyond 3 months.

Results: Forty one patients were identified. Five of the 41 (12%) patients underwent colectomy within 3 months, and one patient was lost to follow-up. Six of 35 (17%) of the remaining patients progressed to colectomy by 12 months. Maintenance therapy: Patients maintained on thiopurine monotherapy (14/35) versus IFX/thiopurine therapy (15/35) were followed up. Two of 15 (13%) patients who received combination maintenance therapy underwent a colectomy at 12 months, compared with 1/14 (7%) patients receiving thiopurine monotherapy (P = 0.610). Monitoring during maintenance: Post-discharge, thiopurine metabolites were monitored in 15/27 (56%); fecal calprotectin in 11/32 (34%); and serum IFX levels in 4/20 (20%). Twenty of 32 (63%) patients had an endoscopic evaluation after IFX salvage with median time to first endoscopy of 109 days (interquartile range 113-230).

Conclusion: Following IFX induction therapy for ASUC, the uptake of maintenance therapy in this cohort and strategies to monitor ongoing response were variable. These data suggest that the optimal maintenance and monitoring strategy post-IFX salvage therapy remains to be defined.
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http://dx.doi.org/10.1111/jgh.13850DOI Listing
January 2018

Update on a previously reported male with a FLNA missense mutation.

Eur J Hum Genet 2017 08 4;25(8):905-906. Epub 2017 Jan 4.

Adult Genetic Medicine, Royal Melbourne Hospital, Melbourne, VIC, Australia.

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http://dx.doi.org/10.1038/ejhg.2016.156DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5567143PMC
August 2017

The management of gastro-oesophageal reflux disease.

Aust Prescr 2016 Feb 1;39(1):6-10. Epub 2016 Feb 1.

Launceston General Hospital, Tasmania.

If there are no features of serious disease, suspected gastro-oesophageal reflux disease can be initially managed with a trial of a proton pump inhibitor for 4-8 weeks. This should be taken 30-60 minutes before food for optimal effect. Once symptoms are controlled, attempt to withdraw acid suppression therapy. If symptoms recur, use the minimum dose that controls symptoms. Patients who have severe erosive oesophagitis, scleroderma oesophagus or Barrett's oesophagus require long-term treatment with a proton pump inhibitor. Lifestyle modification strategies can help gastro-oesophageal reflux disease. Weight loss has the strongest evidence for efficacy. Further investigation and a specialist referral are required if there is no response to proton pump inhibitor therapy. Atypical symptoms or signs of serious disease also need investigation.
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http://dx.doi.org/10.18773/austprescr.2016.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4816873PMC
February 2016

A randomized controlled trial of light versus deep propofol sedation for elective outpatient colonoscopy: recall, procedural conditions, and recovery.

Can J Anaesth 2015 Nov 3;62(11):1169-78. Epub 2015 Sep 3.

Cogstate Ltd, Melbourne, Australia.

Purpose: This study aimed to determine if the incidence of recall was equivalent between light and deep sedation for colonoscopy. Secondary analysis included complications, patient clinical recovery, and post-procedure cognitive impairment.

Methods: Two hundred patients undergoing elective outpatient colonoscopy were randomized to light (bispectral index [BIS] 70-80) or deep (BIS < 60) sedation with propofol and fentanyl. Recall was assessed by the modified Brice questionnaire, and cognition at baseline and discharge was assessed using a Cogstate test battery.

Results: The median (interquartile range [IQR]) BIS values were different in the two groups (69 [65-74] light sedation vs 53 [46-59] deep sedation; P < 0.0001). The incidence of recall was 12% in the light sedation group and 1% in the deep sedation group. The risk difference for recall was 0.11 (90% confidence interval, 0.05 to 0.17) in the intention-to-treat analysis, thus refuting equivalence in recall between light and deep sedation (0.05 significance level; 10% equivalence margin). Overall sedation-related complications were more frequent with deep sedation than with light sedation (66% vs 47%, respectively; P = 0.008). Recovery was more rapid with light sedation than with deep sedation as determined by the mean (SD) time to reach a score of 5 on the Modified Observer's Assessment of Alertness/Sedation Scale [3 (4) min vs 7 (4) min, respectively; P < 0.001] and by the median [IQR] time to readiness for hospital discharge (65 [57-80] min vs 74 [63-86] min, respectively; P = 0.001). The incidence of post-procedural cognitive impairment was similar in those randomized to light (19%) vs deep (16%) sedation (P = 0.554).

Conclusion: Light sedation was not equivalent to deep sedation for procedural recall, the spectrum of complications, or recovery times. This study provides evidence to inform discussions with patients about sedation for colonoscopy. This trial was registered at the Australian and New Zealand Clinical Trials Registry, number 12611000320954.
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http://dx.doi.org/10.1007/s12630-015-0463-3DOI Listing
November 2015

Abnormal structure and function of the esophagogastric junction and proximal stomach in gastroesophageal reflux disease.

Am J Gastroenterol 2014 May 4;109(5):658-67. Epub 2014 Mar 4.

1] Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland [2] Nottingham Digestive Diseases Centre and Biomedical Research Unit, University Hospital, Nottingham, UK.

Objectives: This study applies concurrent magnetic resonance imaging (MRI) and high-resolution manometry (HRM) to test the hypothesis that structural factors involved in reflux protection, in particular, the acute insertion angle of the esophagus into the stomach, are impaired in gastroesophageal reflux disease (GERD) patients.

Methods: A total of 24 healthy volunteers and 24 patients with mild-moderate GERD ingested a test meal. Three-dimensional models of the esophagogastric junction (EGJ) were reconstructed from MRI images. Measurements of the esophagogastric insertion angle, gastric orientation, and volume change were obtained. Esophageal function was assessed by HRM. Number of reflux events and EGJ opening during reflux events were assessed by HRM and cine-MRI. Statistical analysis applied mixed-effects modeling.

Results: The esophagogastric insertion angle was wider in GERD patients than in healthy subjects (+7° ± 3°; P=0.03). EGJ opening during reflux events was greater in GERD patients than in healthy subjects (19.3 mm vs. 16.8 mm; P=0.04). The position of insertion and gastric orientation within the abdomen were also altered (both P<0.05). Median number of reflux events was 3 (95% CI: 2.5-4.6) in GERD and 2 (95% CI: 1.8-3.3) in healthy subjects (P=0.09). Lower esophageal sphincter (LES) pressure was lower (-11 ± 2 mm Hg; P<0.0001) and intra-abdominal LES length was shorter (-1.0 ± 0.3 cm, P<0.0006) in GERD patients.

Conclusions: GERD patients have a wider esophagogastric insertion angle and have altered gastric morphology; structural changes that could compromise reflux protection by the "flap valve" mechanism. In addition, the EGJ opens wider during reflux in GERD patients than in healthy volunteers: an effect that facilitates volume reflux of gastric contents.
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http://dx.doi.org/10.1038/ajg.2014.25DOI Listing
May 2014

Scleroderma with a twist.

Am J Gastroenterol 2010 Oct;105(10):2297-9

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http://dx.doi.org/10.1038/ajg.2010.237DOI Listing
October 2010

Gastroesophageal junction: structure and function as assessed by using MR imaging.

Radiology 2010 Oct 16;257(1):115-24. Epub 2010 Aug 16.

Institute for Biomedical Engineering, University of Zurich and Swiss Federal Institute of Technology, Zurich, Switzerland.

Purpose: To develop and validate magnetic resonance (MR) imaging protocols for quantitative assessment of the structural and functional properties of the gastroesophageal junction (GEJ) and to compare MR imaging detection of reflux events against concurrent manometry as a reference method.

Materials And Methods: The local ethics committee approved this study, and written informed consent was obtained. Twelve healthy volunteers were examined. Three-dimensional models of the GEJ and proximal portion of the stomach were reconstructed from high-spatial-resolution anatomic MR images to assess the insertion angle of the esophagus into the stomach and proximal stomach distention before and after ingestion of a large test meal. A linear mixed-effects model was used to detect differences in the insertion angle and proximal stomach distention with respect to the respiratory cycle and gastric filling. Additionally, dynamic MR imaging at high temporal resolution was used to detect reflux events.

Results: The esophageal insertion angle, given in units of plane angle (radians), was more acute in expiration than in inspiration (0.57 vs 0.73 radian, P = .004) but was not affected by feeding. Progressive distention of the proximal stomach was observed from baseline compared with the postprandial period (0.95 vs 0.65 radian(-1), P < .05). Eighteen reflux events detected by using MR imaging were also detected by using manometry.

Conclusion: MR imaging methods were developed and validated for the assessment of GEJ structure and function (a) to describe the effects of respiration and feeding on the reflux barrier and (b) to detect reflux events in real time. Anatomic and dynamic MR imaging may be useful techniques in the assessment of GEJ physiology and reflux.
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http://dx.doi.org/10.1148/radiol.10092340DOI Listing
October 2010

Increased intragastric pressure gradients are involved in the occurrence of acid reflux in gastroesophageal reflux disease.

Scand J Gastroenterol 2009 ;44(5):545-50

Department of Gastroenterology, University Medical Center Utrecht, Utrecht, The Netherlands.

Objective: Increased pressure gradients across the esophagogastric junction (DeltaEGJp) play a role in gastroesophageal flow during TLESR. The aim of this study was to further explore DeltaEGJp in patients with gastroesophageal reflux disease (GERD) and controls.

Material And Methods: Twenty GERD patients were studied along with 20 control subjects. High resolution manometry and pH recording were performed 1 h before and 2 h after a liquid meal (500 ml/300 kcal). DeltaEGJp was calculated at the start of a TLESR and at 180, 60, and 10 s before TLESR.

Results: DeltaEGJp at the start of a TLESR and at 180, 60, and 10 s before TLESR was markedly increased in GERD patients compared with that in control subjects (9.9 mmHg and 7.5 mmHg, respectively; p<0.05). Whilst intragastric pressure gradients in GERD patients were increased compared with those in controls (4.6 mmHg and 2.5 mmHg, respectively; p<0.01), intraesophageal pressure gradients were similar in both groups. Furthermore, in controls, first- and second-hour postprandial intragastric pressures were decreased compared with in fasting periods (1.9 +/- 0.4 mmHg and 2.1 +/- 0.4 mmHg versus 3.5 +/- 0.4 mmHg; p<0.05), while this was not observed in GERD patients.

Conclusions: In GERD patients, DeltaEGJp is greater than that in controls both before and during TLESR. This phenomenon is caused by increased intragastric pressure and might contribute to increased rates of acid reflux during TLESR in GERD patients.
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http://dx.doi.org/10.1080/00365520902718903DOI Listing
July 2009

Age and gender affect likely manometric diagnosis: Audit of a tertiary referral hospital clinical esophageal manometry service.

J Gastroenterol Hepatol 2009 Jan 18;24(1):125-8. Epub 2008 Aug 18.

Department of Gastroenterology and Hepatology, Royal Adelaide Hospital, Adelaide, Australia.

Background And Aim: Awareness of patient demographics, common diagnoses and associations between these may improve the use and interpretation of manometric investigations. The aim of the present study therefore was to determine whether age and/or gender affect manometric diagnosis in a clinical motility service.

Methods: An audit of all 452 clinical manometry reports issued from December 2003 to July 2005 with respect to age, gender and diagnosis was carried out. Patients were divided by age (17-24 years n = 14, 25-44 years n = 87, 45-64 years n = 216 and >or=65 years n = 135), and gender and data compared using contingency tables.

Results: Women were more commonly referred overall (59%) and in each age bracket except <25 years (64% male). Men were more likely to have 'hypotensive' motor problems P = 0.01. With aging, normal motor function became less common (P = 0.013), with non-specific motor disorder, ineffective/hypotensive peristalsis and 'achalasia-like' conditions each more common (individual P = NS). Increasing age showed a trend for increased spastic motor disorders (P = 0.06). Gender did not, however, influence whether motility was abnormal (P = 0.5), spastic (P = 0.7) or whether a non-specific motor disorder was present (P = 0.1). In the total cohort, the principal manometric diagnoses were: non-specific motor disorder 33%, normal motility 29%, low basal lower esophageal sphincter pressure 18%, hypotensive/ineffective peristalsis 10%, achalasia/achalasia-like 6%, diffuse esophageal spasm 3% and other 1%.

Conclusions: Aging leads to increasing esophageal motor abnormalities. Men and women have similar rates of dysfunction, although 'low-pressure problems' were more common in men.
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http://dx.doi.org/10.1111/j.1440-1746.2008.05561.xDOI Listing
January 2009

Symmetrical pouch dilatation after laparoscopic adjustable gastric banding: incidence and management.

Obes Surg 2008 Sep 23;18(9):1104-8. Epub 2008 Apr 23.

Centre for Obesity Research and Education, Monash University, Melbourne, Australia,

Background: Laparoscopic adjustable gastric banding (LAGB) has commonly been complicated by the problem of band slippage or prolapse. Since popularization of the pars flaccida approach and improved anterior fixation, it is our impression that the problem of symmetrical dilatation of the proximal gastric pouch has become more important.

Methods: We have reviewed the results of a series of 425 LAGB all performed by the pars flaccida approach from June 2003 to October 2007 to analyze the incidence and implications of this new pattern.

Results: There were no posterior prolapses, 2 anterior prolapses, and 17 cases of symmetrical pouch dilatation (SPD) (revision rate 4.4%). Teenage patients had a 22% revision rate for SPD. All revisions were completed laparoscopically with no mortality, no significant complications, and a median hospital stay of 1 day. The median weight loss following revisional surgery was not significantly different from the background cohort.

Conclusion: SPD is the most common reason for revision of LAGB in this series. We postulate that SPD is caused by excessive pressure in the proximal gastric pouch. This may be generated either by eating too quickly or too large a volume or excessive tightening of the band. The radial forces in the pouch may ultimately cause pressure on the phrenoesophageal ligament and a secondary hiatal hernia.
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http://dx.doi.org/10.1007/s11695-008-9485-zDOI Listing
September 2008

Quantification of distal antral contractile motility in healthy human stomach with magnetic resonance imaging.

J Magn Reson Imaging 2006 Nov;24(5):1101-9

Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.

Purpose: To quantify healthy postprandial: 1) propagation, periodicity, geometry, and percentage occlusion by distal antral contraction waves (ACWs); and 2) changes in ACW activity in relationship to gastric emptying (GE).

Materials And Methods: Using 1.5-T MR scanner, nine healthy fasted volunteers were examined in the right decubitus position after ingestion of 500 mL of 10% glucose (200 kcal) with 500 microM Gd-DOTA. Total gastric (TGV) and meal volumes (MV) were assessed every five minutes for 90 minutes, in and interspersed with dynamic scan sequences (duration: 2.78 minutes) providing detailed images of distal ACWs.

Results: TGV increased by 738+/-38 mL after ingestion (t0), subsequently decreasing in parallel to GE. The mean GE rate and half-emptying time were 24+/-3 mL/5 minutes and 71+/-6 minutes, respectively. Accompanying ACWs reached a periodicity of 23+/-2 seconds at t35 and propagated at an unvarying speed of 0.27+/-0.01 cm/second. Their amplitude of 0.70+/-0.08 cm was constant, but the width decreased along the antral wall by 6+/-2%/cm (P=0.003). ACWs were nonocclusive (percentage occlusion 58.1+/-5.9%, t0 at the pylorus) with a reduction in occlusion away from the pylorus (P<0.001). No propagation and geometry characteristics of ACWs correlated with the changes of MV (mL/5 minutes; R2<0.05).

Conclusion: Our results indicate that ACWs are not imperative for emptying of liquids. This study provides a detailed quantitative reference for MRI inquiries into pharmacologically- and pathologically-altered gastric motility.
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http://dx.doi.org/10.1002/jmri.20738DOI Listing
November 2006

Physiology of the esophageal pressure transition zone: separate contraction waves above and below.

Am J Physiol Gastrointest Liver Physiol 2006 Mar 10;290(3):G568-76. Epub 2005 Nov 10.

Department of Mechanical Engineering, The Pennsylvania State University, 205 Reber Bldg., University Park, PA 16802, USA.

Manometrically measured peristaltic pressure amplitude displays a well-defined trough in the upper esophagus. Whereas this manometric "transition zone" (TZ) has been associated with striated-to-smooth muscle fiber transition, the underlying physiology of the TZ and its role in bolus transport are unclear. A computer model study of bolus retention in the TZ showed discoordinated distinct contraction waves above and below. Our aim was to test the hypothesis that distinct upper/lower contraction waves above/below the manometric TZ are normal physiology and to quantify space-time coordination between tone and bolus transport through the TZ. Eighteen normal barium swallows were analyzed in 6 subjects with concurrent 21-channel high-resolution manometry and digital fluoroscopy. From manometry, the TZ center (nadir pressure amplitude) and the upper/lower margins of the pressure trough were objectively quantified. Using fluoroscopy, we quantified space-time trajectories of the bolus tail and bolus tail pressures and maximum intraluminal pressures proximal to the tail with their space-time trajectories. In every swallow, the bolus tail followed distinct trajectories above/below the TZ, separated by a well-defined spatial "jump" that terminated an upper contraction wave and initiated a lower contraction wave (3.32 +/- 1.63 cm, P = 0.0004). An "indentation wave" always formed within the TZ distal to the upper wave, increasing in amplitude until the lower wave was initiated. As the upper contraction wave tail entered the TZ, it slowed and the tail pressure reduced rapidly, while indentation wave pressure increased to normal tail pressure values at the initiation of the lower wave. The TZ was a special zone of segmental contraction. The TZ is, physiologically, the transition from an upper contraction wave originating in the proximal striated esophagus to a lower contraction wave that moves into the distal smooth muscle esophagus. Complete bolus transport requires coordination of upper/lower waves and sufficient segmental squeeze to fully clear the bolus from the TZ during the transition period.
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http://dx.doi.org/10.1152/ajpgi.00280.2005DOI Listing
March 2006

Colorectal cancer prevention.

Med J Aust 2002 Nov;177(9):527; author reply 527-8

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http://dx.doi.org/10.5694/j.1326-5377.2002.tb04939.xDOI Listing
November 2002