Geoff Hebbard

Pathophysiology of Laparoscopic Adjustable Gastric Bands: Analysis and Classification Using High-Resolution Video Manometry and a Stress Barium Protocol

BackgroundSymmetrical pouch dilatation has become the most common problem following laparoscopic adjustable gastric banding (LAGB). Although, in a significant number of symptomatic patients, no explanation for the underlying problem is identified with a contrast swallow. There is a need for a better understanding of the pathophysiology of LAGBs and more sensitive diagnostic tests.MethodsLAGB patients with adverse symptoms or poor weight loss (symptomatic patients), in whom a contrast swallow had not shown an abnormality, underwent high-resolution video manometry. This incorporated a semi-solid, stress barium, swallow protocol. Outcomes were categorized based on anatomical appearance, transit through the LAGB, and esophageal motility. Cohorts of successful (>50% excess weight loss with no adverse symptoms) and pre-operative patients were used as controls.ResultsOne hundred twenty-three symptomatic patients participated along with 30 successful and 56 pre-operative patients. Five pathophysiological patterns were defined: transhiatal enlargement (n = 40), sub-diaphragmatic enlargement (n = 39), no abnormality (n = 30), aperistaltic esophagus (n = 7), and intermittent gastric prolapse (n = 3). Esophageal motility disorders were more common in symptomatic and pre-operative patients than in successful patients (p = 0.01). Differences between successful and symptomatic patients were identified in terms of the length of the high-pressure zone above the LAGB (p < 0.005), peristaltic velocity (p < 0.005), frequency of previous surgery(p = 0.01), and lower esophageal sphincter tone (p = 0.05).ConclusionsVideo manometry identified abnormalities in three quarters of symptomatic patients where conventional contrast swallow had not been diagnostic. Five primary patterns of pathophysiology were defined. These were used to develop a seven category, clinical, classification system based on the anatomical appearance at stress barium. This system stratifies the spectrum of symmetrical pouch dilatation and can be used to logically guide treatment.

Australian clinical practice guidelines for the diagnosis and management of Barrett's esophagus and early esophageal adenocarcinoma

Barretts esophagus (BE), a common condition, is the only known precursor to esophageal adenocarcinoma (EAC). There is uncertainty about the best way to manage BE as most people with BE never develop EAC and most patients diagnosed with EAC have no preceding diagnosis of BE. Moreover, there have been recent advances in knowledge and practice about the management of BE and early EAC. To aid clinical decision making in this rapidly moving field, Cancer Council Australia convened an expert working party to identify pertinent clinical questions. The questions covered a wide range of topics including endoscopic and histological definitions of BE and early EAC; prevalence, incidence, natural history, and risk factors for BE; and methods for managing BE and early EAC. The latter considered modification of lifestyle factors; screening and surveillance strategies; and medical, endoscopic, and surgical interventions. To answer each question, the working party systematically reviewed the literature and developed a set of recommendations through consensus. Evidence underpinning each recommendation was rated according to quality and applicability.

Criteria for Assessing Esophageal Motility in Laparoscopic Adjustable Gastric Band Patients: The Importance of the Lower Esophageal Contractile Segment

BackgroundEsophageal function appears critical in laparoscopic adjustable gastric band (LAGB) patients; however, conventional motility assessments have not proven to be clinically useful. Recent combined video fluoroscopic and high-resolution manometric studies have identified important components of esophageal function in LAGB patients.MethodsSuccessful and symptomatic LAGB patients, with normal or mildly impaired esophageal peristalsis, underwent a standardized, water swallow, high-resolution manometry protocol designed specifically to assess the lower esophageal contractile segment (LECS), in combination with conventional measures of esophageal motility. Differences in response to changes in LAGB volume were assessed.ResultsThere were 101 symptomatic and 29 successful patients. More symptomatic patients had a mild impairment in esophageal motility (39.6% vs. 3.4%, p < 0.005). Successful patients demonstrated an intact LECS during normal swallows more frequently than symptomatic patients (95% vs. 43%, p < 0.005). Absolute intraluminal pressures were not different between the groups. Removing all fluid from the LAGB revealed more hypotensive swallows in the symptomatic patients (30% vs. 17%, p = 0.002), an effect not observed when the LAGB volume was increased (8% vs. 5%, p = 0.21). Receiver operator characteristic analysis determined that an intact LECS in 70% of normal swallows defined normal motility in LAGB patients.ConclusionsThe LECS is a valuable measure of esophageal function in LAGB patients and complements conventional manometric criteria. Symptomatic patients have less normal swallows; however, these also frequently demonstrate a deficient LECS. Further information can be elucidated by performing swallows at differing LAGB volumes. High-resolution manometry, using these adapted criteria, is now a useful in the investigation in symptomatic LAGB patients.

Effects of partial (Belsey Mark IV) and complete (Nissen) fundoplication on proximal gastric function and esophagogastric junction dynamics.

OBJECTIVES:This study aimed to assess the effects of Belsey Mark IV 270° (partial) and Nissen 360° (complete) fundoplication on proximal stomach function, transient lower esophageal sphincter relaxation (TLESR) elicitation and the esophagogastric junction (EGJ) pressure profile during TLESR to further elucidate the mechanism of action of fundoplication.METHODS:Ten patients after partial and 10 patients after complete fundoplication were studied. High-resolution EGJ manometry and pH recording were performed for 1 h at baseline and 2 h following meal ingestion (500 mL/300 kcal). Three dimensional (3D) ultrasonographic images of the stomach were acquired every 15 min after meal ingestion. From the 3D ultrasonographic images, proximal gastric volumes were computed.RESULTS:Postprandial proximal to complete gastric volume distribution ratios were larger among patients after partial (0.42 ± 0.028) compared with patients after complete fundoplication (0.37 ± 0.035; p < 0.05). Partial fundoplication patients had a markedly greater postprandial rate of TLESR (1.7 ± 0.3/h) than patients after complete fundoplication (0.8 ± 0.2/h; p < 0.05). The axial EGJ pressure profile was minimally affected by partial fundoplication but instead markedly changed after complete fundoplication.CONCLUSIONS:Patients after partial fundoplication exhibit a larger meal-induced increase in proximal stomach volume, a higher TLESR rate, and a minimally affected axial EGJ pressure profile compared to patients after complete fundoplication.

Relations between symptom severity, illness perceptions, visceral sensitivity, coping strategies and well-being in irritable bowel syndrome guided by the common sense model of illness

Abstract Irritable Bowel Syndrome (IBS) is a common condition affecting around 10–20% of the population and associated with poorer psychological well-being and quality of life. The aim of the current study was to explore the efficacy of the Common Sense Model (CSM) using Structural Equation Modelling (SEM) in an IBS cohort. One hundred and thirty-one IBS patients (29 males, 102 females, mean age 38 years) participating in the IBSclinic.org.au pre-intervention assessment were included. Measures included IBS severity (Irritable Bowel Syndrome Severity Scoring System), coping patterns (Carver Brief COPE), visceral sensitivity (Visceral Sensitivity Index), illness perceptions (Brief Illness Perceptions Questionnaire), psychological distress (Depression, Anxiety and Stress Scale), and quality of life (IBS Quality of Life scale; IBS-QoL). Using SEM, a final model with an excellent fit was identified (χ2 (8) = 11.91, p = .16, χ2/N = 1.49, CFI > .98, TLI > .96, SRMR < .05). Consistent with the CSM, Illness perceptions were significantly and directly influenced by IBS severity (β = .90, p < .001). Illness perceptions in turn directly influenced maladaptive coping (β = .40, p < .001) and visceral sensitivity (β = .70, p < .001). Maladaptive coping and visceral sensitivity were significantly associated with psychological distress (β = .55, p < .001; β = .22, p < .01) and IBS-QoL (β = –.28, p < .001; β = –.62, p < .001). Based on these findings, we argue that to augment the adverse impact of IBS severity on IBS-QoL and psychological distress, psychological interventions will be best to target the mediating psychological processes including illness beliefs, visceral sensitivity and maladaptive coping.

Predicting Outcomes of Intermediate Term Complications and Revisional Surgery Following Laparoscopic Adjustable Gastric Banding: Utility of the CORE Classification and Melbourne Motility Criteria

BackgroundPatients with laparoscopic adjustable gastric bands (LAGB) present at times with adverse symptoms or unsatisfactory weight loss, where a liquid contrast swallow or upper gastrointestinal endoscopy is not diagnostic. Stress barium and high resolution manometry are promising investigations, however, have not yet been established as clinically useful.MethodsPatients with an unsatisfactory outcome following LAGB, where liquid contrast swallow and endoscopy were not diagnostic, were evaluated using high resolution video manometry and a stress barium. Pre-operative and follow-up clinical data were collected. Esophageal motility was assessed using the Melbourne criteria.ResultsThere were 143 participants in the study. Stress barium identified the following appearances: gastric enlargement (n = 57), transhiatal enlargement (n = 44), pan-esophageal dilatation (n = 9), and anatomically normal (n = 33). Twenty-four (72%) of the anatomically normal patients had deficient esophageal motility. Revisional LAGB surgery was performed in 56 patients. This was successful in gastric enlargements when motility was intact (percentage of excess weight loss (%EWL) 58.3 ± 16.2 vs. 35.4 ± 19.7, p = 0.002). Revisional surgery for transhiatal enlargements improved symptoms but did not improve poor weight loss (%EWL 20.6 ± 24.9 vs. 17.2 ± 25, p = 0.1).ConclusionsThe CORE classification combines anatomical change with esophageal motility and has been defined for intermediate term complications following LAGB where conventional investigations have not been diagnostic. Revisional LAGB surgery is helpful for patients with a gastric enlargement above the LAGB if esophageal motility is intact. If motility is deficient or there is an esophageal anatomical abnormality, intervention is not likely to remedy poor weight loss.

Psychological controversies in gastroparesis: A systematic review

AIM To systematically review literature addressing three key psychologically-oriented controversies associated with gastroparesis. METHODS A comprehensive search of PubMed, CINAHL, and PsycINFO databases was performed to identify literature addressing the relationship between gastroparesis and psychological factors. Two researchers independently screened all references. Inclusion criteria were: an adult sample of gastroparesis patients, a quantitative methodology, and at least one of the following: (1) evaluation of the prevalence of psychopathology; (2) an outcome measure of anxiety, depression, or quality of life; and (3) evidence of a psychological intervention. Case studies, review articles, and publications in languages other than English were excluded from the current review. RESULTS Prevalence of psychopathology was evaluated by three studies (n = 378), which found that combined anxiety/depression was present in 24% of the gastroparesis cohort, severe anxiety in 12.4%, depression in 21.8%-23%, and somatization in 50%. Level of anxiety and depression was included as an outcome measure in six studies (n = 1408), and while limited research made it difficult to determine the level of anxiety and depression in the cohort, a clear positive relationship with gastroparesis symptom severity was evident. Quality of life was included as an outcome measure in 11 studies (n = 2076), with gastroparesis patients reporting lower quality of life than population norms, and a negative relationship between quality of life and symptom severity. One study assessed the use of a psychological intervention for gastroparesis patients (n = 120) and found that depression and gastric function were improved in patients who received psychological intervention, however the study had considerable methodological limitations. CONCLUSION Gastroparesis is associated with significant psychological distress and poor quality of life. Recommendations for future studies and the development of psychological interventions are provided.

Noncardiac chest pain: An unsatisfactory ‘diagnosis’?

See article in J. Gastroenterol. Hepatol. 2010; 25: 1855–1860.

Building a better mousetrap? Impedance measurement in gastroesophageal reflux disease

The measurement of intraluminal impedance in the investigation of esophagal disorders is a novel technique developed in the early 1990s, initially as a research tool. With the widespread use of potent acid suppression, increasing understanding of non-erosive reflux disease and functional heartburn and, perhaps most importantly, the development of commercially-available measurement systems, multiple intraluminal impedance (MII) measurement is gradually finding its place in clinical practice. In a recent issue, Xiao et al. have used this technique to examine Asian patients with gastroesophageal reflux demonstrating that, despite differences in the epidemiology of reflux in Asia, the underlying patterns of reflux are very similar to those seen in western populations. Intraluminal impedance is the resistance to the flow of a high frequency (but low amplitude) alternating current between a pair of electrodes situated on a catheter within the lumen of a hollow organ (in this case the esophagus). When the esophagus is empty, the current is conducted through the esophageal wall and impedance is relatively high. The presence of fluid in the lumen (e.g. water, gastric contents) reduces the impedance and, because there are multiple measurement points, the direction of movement of the fluid can be determined. In addition, the presence of gas can be detected as a rise in intraluminal impedance (as gas has a higher impedance than tissue or fluid). Typically intraluminal pH is also measured and this combination is termed MII-pH. Being sensitive to the presence and position of the fluid and gas components of reflux in addition to acid increases sensitivity and allows episodes of gastroesophageal reflux to be subclassified by the presence of acid (acidic, weakly acidic), gas (liquid only, liquid and gas, gas only) and extent of reflux. Clearly MII-pH is a powerful tool for studying the pathophysiology and symptomatology of reflux disease, effects of treatment and the reasons for treatment failure. Limitations of the technique for the assessment of reflux include that the facts that swallowed liquids also cause a drop in impedance (although from top to bottom rather than bottom up as in gastroeosophageal reflux), and that several conditions (e.g. severe esophagitis, Barrett’s esophagus and achalasia) can reduce the baseline impedance. In addition, artifact may be a problem and analysis can be time consuming with reliable algorithms still being developed. Normative data is available but less well established than with pH analysis alone, and intraand interobserver variability although acceptable in experienced hands, has not been determined in routine clinical practice. Patients still need to undergo esophageal manometry prior to the ambulatory impedance study in order to determine the optimal placement of the catheter, tolerate the transnasal catheter and carry a recorder for 24 h. Similarly to ambulatory catheter-based pH studies, one would expect that the associated lifestyle modifications may occasionally lead to some difficulties with determining whether the recording period is ‘typical’ of the patient’s disease. MII-pH has generated significant insights into the pathophysiology of gastro-esophageal reflux disease and the effects of treatment, demonstrating that ‘traditional’ pH measurement and criteria for the detection of episodes of reflux are not as sensitive as previously assumed, that pH normalization after a reflux event generally takes considerably longer than volume clearance, and that proton pump inhibitors (PPIs) affect the pH, but not the frequency of underlying reflux events. Reflux events can be classified as acidic, weakly acidic or nonacid (weakly alkaline). The absolute and relative frequencies of these types of event and the symptoms associated with each have been examined in subpopulations of patients with reflux symptoms in attempts to classify patients based on the underlying pathophysiology, and therefore to guide management. The study reported in this issue of the journal examines the patterns of gastroesophageal reflux and symptoms in Asian patients with erosive and nonerosive reflux disease compared to patients with functional heartburn (reflux symptoms, no excessive acid exposure, negative symptom association) and normal individuals. The epidemiology of reflux disease in Asian countries differs from that in the west, with a lower prevalence of disease (but evidence that it is rising) and a predominance of less severe disease. Nevertheless, the underlying patterns of reflux were found to be similar, with more acid and liquid reflux in patients with erosive and nonerosive reflux disease, and the reflux profile of the functional heartburn patients resembling that of the healthy controls. One might argue that there is a degree of circularity in the use of pH data in the separation of the nonerosive reflux disease and functional heartburn patients, then using the same parameter (although now combined with impedance data) in the analysis. This, however, really reflects the lack of an independent gold standard for separating these groups and our limited understanding of the condition of functional heartburn (which is believed to relate to hypersensitivity or psychological factors rather than directly to acid reflux). MII-pH is yet to establish its place in the routine clinical management of patients with reflux disease, but does have significant potential advantages over pH studies. A common situation is where a patient with either atypical or extraesophageal*** symptoms that are believed to be due to gastrooesohageal reflux has not responded to treatment with PPIs. The patient may be being evaluated for surgery (fundoplication), and in this situation the stakes are high, as if the symptoms are not due to reflux, not only will a fundoplication be ineffective in relieving the symptoms, but troublesome new symptoms may be induced. Without corroborative evidence of reflux that is either pathological or associated in time with symptoms, the likelihood that surgery will be successful in relieving the symptoms is much lower. The traditional approach in this situation has been to perform an ambulatory 24 h pH study Accepted for publication 26 May 2009.