Oesophageal disorders: future developments

Elicitation of the characteristic symptom patterns remains the primary approach to the diagnosis of gastro-oesophageal reflux disease, and this may be enhanced by developments in the use of high-resolution endoscopy and oesophageal biopsy. For future therapy, proton pump inhibitors and anti-reflux surgery may compete with reversible acid pump blockers, reflux inhibitor drugs and diverse luminally delivered physical anti-reflux therapies. Short-segment Barrett's oesophagus is known to be highly prevalent, but its impact on the risk of adenocarcinoma remains poorly defined. Biomarkers for Barrett's oesophagus have been proposed to aid in the stratification of cancer risk, and cytology may assume more importance in the future. Endoscopic surveillance for Barrett's oesophagus is widely practised, but more data are needed to demonstrate cost-effectiveness and a positive impact on mortality. Animal and limited human studies suggest that chemoprevention may become an important strategy in reducing the risk of adenocarcinoma. The ablation of Barrett's epithelium results in a reversal of Barrett's epithelium, albeit with an uncertain long-term outcome.

Mechanisms of gastro-oesophageal reflux in preterm and term infants with reflux disease

BACKGROUND

Transient lower oesophageal sphincter relaxation (TLOSR) is the predominant mechanism of gastro-oesophageal reflux (GOR) in healthy infants but the mechanisms of GOR in infants with GOR disease (GORD) are poorly understood.

AIMS

To measure the occurrence of TLOSR, GOR, and gastric emptying (GE) rate in preterm and term infants with GORD.

PATIENTS

Thirty six infants were studied and grouped as normals or GORD based on a routine clinical assessment and confirmation of an assessment of GORD by reflux symptom charts and oesophageal pH monitoring.

METHODS

A micromanometric assembly incorporating a micro pH electrode recorded oesophageal motility and pH. GE rate was determined using the (13)C-octanoic acid breath test.

RESULTS

TLOSR was the predominant mechanism of GOR, triggering 50-100% of GOR episodes (median 91.5%). Abdominothoracic straining significantly increased the occurrence of GOR in association with TLOSR. In infants with GORD, the number of TLOSRs overall was similar to normals but the proportion of TLOSRs accompanied by acid GOR was significantly higher than in normals (16.5% v 5.7%, respectively; p<0.001). Infants with GORD had a similar GE rate to normals.

CONCLUSIONS

In infant GORD, acid reflux associated TLOSRs are abnormally common and likely to be a major contributing factor to the pathophysiology of GORD. Infants with GORD do not have delayed GE.

Patterns of antropyloric motility in fed healthy preterm infants

BACKGROUND

Antropyloric motility is important for regulation of gastric emptying and has not been adequately characterised in premature infants.

AIM

To evaluate fed patterns of antropyloric motility in premature infants.

SUBJECTS

Forty three healthy premature infants, 30-38 weeks of postmenstrual age.

METHODS

Postprandial antropyloric motility was measured using a micromanometric feeding assembly (outer diameter 1.8 mm) incorporating a pyloric sleeve sensor. The occurrence of isolated pyloric pressure waves (IPPWs) and antral pressure wave sequences (PWSs) was characterised. Sequences were further classified as being antegrade, synchronous, antegrade-synchronous, and retrograde according to the direction of propagation.

RESULTS

A total of 7289 pressure wave events were recorded, 48% IPPWs and 52% PWSs (18% antegrade, 12% synchronous, 13% antegrade-synchronous, 2% retrograde, and 7% undefined). IPPWs predominated in the first postprandial hour, peaking at 30-60 minutes. PWSs predominated in the period after one hour postprandially. Mean (SEM) half gastric emptying time was 42 (4) minutes.

CONCLUSIONS

Monitoring of antropyloric motor patterns in healthy premature infants indicates that the neuroregulatory mechanisms responsible for the coordination of antropyloric motility and gastric emptying are well developed by 30 weeks of postmenstrual age.

Impact of Helicobacter pylori eradication on heartburn in patients with gastric or duodenal ulcer disease -- results from a randomized trial programme

BACKGROUND

Helicobacter pylori infection has been proposed as a protective factor against the development of gastro-oesophageal reflux disease.

AIM

To study heartburn and endoscopic findings before and after H. pylori eradication therapy in patients with peptic ulcer disease.

METHODS

In a multicentre trial programme, patients (n = 1497) were randomized to the omeprazole triple therapy group or to the control group, and were followed for 1-6 months after treatment. Patients in whom the infection was eradicated were compared with those in whom infection persisted. The severity of heartburn was measured at baseline and at each return visit. Endoscopy was performed 6 months after therapy in two of the five studies.

RESULTS

In patients with duodenal ulcer, there was a significantly lower prevalence of heartburn after successful eradication of H. pylori relative to that after failed eradication (estimated odds ratio, 0.48). The reduction in the prevalence of heartburn in patients with gastric ulcer was independent of the post-treatment H. pylori status. In studies in which ulcer relapse was included in the model, this factor emerged as a significant factor for heartburn. The observed incidence of oesophagitis at the last visit was not influenced by H. pylori status.

CONCLUSIONS

Eradication of H. pylori in patients with peptic ulcer disease was associated with a reduced prevalence of heartburn. Prevention of ulcer relapse could be the true cause of this reduction.

Impact of Helicobacter pylori eradication on heartburn in patients with gastric or duodenal ulcer disease -- results from a randomized trial programme

BACKGROUND

Helicobacter pylori infection has been proposed as a protective factor against the development of gastro-oesophageal reflux disease.

AIM

To study heartburn and endoscopic findings before and after H. pylori eradication therapy in patients with peptic ulcer disease.

METHODS

In a multicentre trial programme, patients (n = 1497) were randomized to the omeprazole triple therapy group or to the control group, and were followed for 1-6 months after treatment. Patients in whom the infection was eradicated were compared with those in whom infection persisted. The severity of heartburn was measured at baseline and at each return visit. Endoscopy was performed 6 months after therapy in two of the five studies.

RESULTS

In patients with duodenal ulcer, there was a significantly lower prevalence of heartburn after successful eradication of H. pylori relative to that after failed eradication (estimated odds ratio, 0.48). The reduction in the prevalence of heartburn in patients with gastric ulcer was independent of the post-treatment H. pylori status. In studies in which ulcer relapse was included in the model, this factor emerged as a significant factor for heartburn. The observed incidence of oesophagitis at the last visit was not influenced by H. pylori status.

CONCLUSIONS

Eradication of H. pylori in patients with peptic ulcer disease was associated with a reduced prevalence of heartburn. Prevention of ulcer relapse could be the true cause of this reduction.

Human duodenal phase III migrating motor complex activity is predominantly antegrade, as revealed by high-resolution manometry and colour pressure plots

Abstract Late phase III migrating motor complex activity has been said to be primarily retroperistaltic but has not been assessed with high resolution manometry or three-dimensional colour pressure plots (pressure/time/distance). Duodenal phase III was examined in healthy young volunteers (seven male, two female) with a 20-lumen assembly. With the most proximal sidehole in the distal antrum, after a 4.5-cm interval 18 sideholes at 1.5-cm intervals spanned the duodenum with a final sidehole 3 cm beyond. Fasting pressures were recorded until phase III occurred. Comparisons were made between proximal (P) and distal (D) duodenum during early (E) (first 0.5-1 min) and late (L) (last 0.5-1 min) phase III. With colour pressure analysis, 121 of 180 pressure wave (PW) sequences were purely antegrade, two purely retrograde and 57 bidirectional. Ten of fifty-seven bidirectional PW sequences were complex, branching to become two separate sequences. Bidirectional sequences occurred more frequently in late than early phase III (L 43 vs. E 14 of 57), but their occurrence did not differ between proximal and distal duodenum (P31 vs. D 24 of 57). Antegrade propagation velocity was faster in late compared with early phase III (L 28.50 vs. E 17.05 mm s(-1); P = 0.006), but did not differ between proximal and distal duodenum. Colour pressure analysis also indicated an intermittent segmental pattern to phase III, with each subject exhibiting a change in velocity or direction, or a relative failure of peristalsis somewhere along the duodenum during part of phase III. Duodenal phase III is not homogenous and, in contrast with previous studies, does not primarily constitute a retroperistaltic pump. Colour pressure analysis is useful in interpreting intraluminal pressure profiles and may improve the sensitivity and specificity of clinical studies.

Definitions of reflux disease and its separation from dyspepsia

Management strategies for reflux disease are very different from those for dyspepsia and so differentiating between patients with "true" dyspepsia and those whose primary symptom is heartburn is a key step in their management. This separation has become more clear during the last decade as insights into reflux disease and dyspepsia have improved. It is likely that the use of short self administered questionnaires in routine clinical care will improve the reliability of separation of reflux induced symptoms from true dyspepsia.

Management of reflux disease

The management of reflux disease can be divided into three major phases, the first being diagnosis and severity assessment, the second, prompt initial control of symptoms, and the third, selection of a long term management approach that is tailored to meet individual patient needs and preferences. Throughout these phases of management, the major priorities should include achieving patient satisfaction and minimising management costs.

Shed human enterocytes as a tool for the study of expression and function of intestinal drug-metabolizing enzymes and transporters

OBJECTIVES

Intestinal metabolism and transport are now recognized as protective barriers against orally ingested xenobiotics, including drugs. However, in vitro studies of the expression and function of intestinal proteins are hampered by the limited availability of human intestinal tissues. Because enterocytes are constantly shed in large numbers into the gut lumen, this study investigated whether these cells could be collected with a multilumen perfusion catheter and whether they are functionally active.

METHODS

In healthy volunteers, a 20-cm isolated jejunal segment was generated with the perfusion catheter by inflating 2 balloons with air. Shed cells were characterized by fluorescence-activated cell sorting analysis for leukocyte-specific CD45 and enterocyte-specific villin, as well as for apoptosis. Homogenates of the cells were used for reverse transcriptase polymerase chain reaction and Western blotting. Cytochrome P450 enzyme activity was determined with the calcium channel blocker verapamil as a substrate.

RESULTS

On average, 4.83 mg protein and 56.23 million cells were collected from a 20-cm segment during 2 hours. A total of 84.2% of the cells were positive for enterocyte-specific villin, and only 1.6% of the collected cells were positive for CD45. The majority of cells (65.3%) were not in early or late apoptosis or necrosis. In all volunteers, drug-metabolizing enzymes (such as members of the cytochrome P450 family) could be detected as both messenger ribonucleic acid and proteins. Consistent with expression data, formation of verapamil metabolites catalyzed by CYP3A4 and CYP2C was shown.

CONCLUSIONS

The majority of shed human enterocytes collected with a multilumen perfusion catheter were still functionally active and not apoptotic. Harvesting of spontaneously shed enterocytes provides a new tool for studies on expression and function of intestinal proteins.

Control of transient lower oesophageal sphincter relaxations and reflux by the GABA(B) agonist baclofen in patients with gastro-oesophageal reflux disease

BACKGROUND AND AIMS

Transient lower oesophageal sphincter relaxations (TLOSRs) are the major cause of gastro-oesophageal reflux in normal subjects and in most patients with reflux disease. The gamma aminobutyric acid (GABA) receptor type B agonist, baclofen, is a potent inhibitor of TLOSRs in normal subjects. The aim of this study was to investigate the effect of baclofen on TLOSRs and postprandial gastro-oesophageal reflux in patients with reflux disease.

METHODS

In 20 patients with reflux disease, oesophageal motility and pH were measured, with patients in the sitting position, for three hours after a 3000 kJ mixed nutrient meal. On separate days at least one week apart, 40 mg oral baclofen or placebo was given 90 minutes before the meal.

RESULTS

Baclofen reduced the rate of TLOSRs by 40% from 15 (13.8-18.3) to 9 (5.8-13.3) per three hours (p<0.0002) and increased basal lower oesophageal sphincter pressure. Baclofen also significantly reduced the rate of reflux episodes by 43% from 7.0 (4.0-12.0) to 4.0 (1.5-9) per three hours (median (interquartile range); p<0.02). However, baclofen had no effect on oesophageal acid exposure (baclofen 4.9% (1.7-12.4) v placebo 5.0% (2.7-15.5)).

CONCLUSIONS

In patients with reflux disease, the GABA(B) agonist baclofen significantly inhibits gastro-oesophageal reflux episodes by inhibition of TLOSRs. These findings suggest that GABA(B) agonists may be useful as therapeutic agents for the management of reflux disease.

Effect of cisapride on gastric emptying in premature infants with feed intolerance

OBJECTIVE

To assess the effect of cisapride on gastric emptying and gastro-oesophageal reflux (GOR) symptoms in preterm infants with feed intolerance.

METHODS

Sixteen preterm infants (gestational age 24-35 weeks) with feed intolerance were enrolled in the study. Infants were randomized to receive 7 days of cisapride 0.2 mg/kg four times a day, immediately followed by 7 days of placebo or vice versa. Gastric emptying was measured using the [13C]-octanoic acid breath test prior to study entry and repeated on day 5, 6 or 7 after randomization and 5, 6 or 7 days after crossover. The symptoms of GOR were monitored during the study period using a standardized reflux chart. Weight was recorded daily.

RESULTS

There was no change in gastric emptying in infants prescribed cisapride (gastric half-emptying time (t1/2) 31.9 +/- 4.7 vs 34.2 +/- 3.9 min for placebo vs cisapride, respectively; P = 0.65). Infants on cisapride had slower growth and there was no change in reflux symptoms.

CONCLUSIONS

The use of cisapride in preterm infants with feed intolerance cannot be recommended.

Pressure-geometry relationship in the antroduodenal region in humans

Understanding of the control mechanisms underlying gastric motor function is still limited. The aim of the present study was to evaluate antral pressure-geometry relationships during gastric emptying slowed by intraduodenal nutrient infusion and enhanced by erythromycin. In seven healthy subjects, antral contractile activity was assessed by combined dynamic magnetic resonance imaging and antroduodenal high-resolution manometry. After intragastric administration of a 20% glucose solution (750 ml), gastric motility and emptying were recorded during intraduodenal nutrient infusion alone and, subsequently, combined with intravenous erythromycin. Before erythromycin, contraction waves were antegrade (propagation speed: 2.7 +/- 1.7 mm/s; lumen occlusion: 47 +/- 14%). Eighty-two percent (51/62) of contraction waves were detected manometrically. Fifty-four percent of contractile events (254/473) were associated with a detectable pressure event. Pressure and the degree of lumen occlusion were only weakly correlated (r(2) = 0.02; P = 0.026). After erythromycin, episodes of strong antroduodenal contractions were observed. In conclusion, antral contractions alone do not reliably predict gastric emptying. Erythromycin induces strong antroduodenal contractions not necessarily associated with fast emptying. Finally, manometry reliably detects ~80% of contraction waves, but conclusions from manometry regarding actual contractile activity must be made with care.

Red streaks in the oesophagus in patients with reflux disease: is there a histomorphological correlate?

BACKGROUND

The Los Angeles classification of reflux oesophagitis includes sharply demarcated areas of erythema without any associated slough within the definition of reflux-induced mucosal breaks, though there is uncertainty as to whether these "red streaks" actually represent such a mucosal lesion. This study evaluates the histopathology of these red streaks.

METHODS

Forty patients with one or more red streaks on the tops of the mucosal folds in the distal oesophagus were included in a multinational, multicentre prospective study. All patients were referred for upper gastrointestinal endoscopy to investigate chronic heartburn and acid regurgitation. Biopsies were taken from the red streaks and from control biopsies from more normal appearing mucosa 1 cm lateral to the red streaks. A two-sided probability test using normal approximation assessed differences in the histological findings at the two biopsy locations.

RESULTS

Compared to control biopsies, biopsies of red streaks had a significantly thicker basal cell layer (mean +/- s 41% +/- 32% versus 18% +/- 23% of mucosal thickness, P=0.001) and longer papillae (mean +/- s 71% +/- 19% versus 49% +/- 24% of mucosal thickness, P= 0.001). Of the red streak biopsies, 25% had either newly re-epithelized lesions or granulation tissue beneath squamous epithelium. Only 10% of the control biopsies had moderate or more marked regenerative changes (based on elongation of papillae and basal cell hyperplasia), compared to 65.1% of red streak biopsies. Of the biopsies from the red streak itself, 7% showed no abnormality and 27.9% only slight changes. In comparison, 25% of the biopsies from control biopsies showed no regenerative changes and 62.5% only slight change due to gastro-oesophageal reflux disease.

CONCLUSION

The histomorphological counterpart to the endoscopically visible red streaks of the distal oesophagus is marked regenerative changes of the squamous epithelium and/or capillary rich granulation tissue beneath the squamous epithelium. Red streaks are validated as being indicative of acid/peptic mucosal injury, but they do not satisfy a strict definition of a mucosal break.

Determination of in vivo absorption, metabolism, and transport of drugs by the human intestinal wall and liver with a novel perfusion technique

BACKGROUND AND AIMS

The contribution of the gastrointestinal tract in comparison with the liver for the low and variable bioavailability of orally administered drugs is still poorly understood. Here we report on a new intestinal perfusion technique for the direct assessment of absorption, metabolism, and transport of drugs by the intestinal wall.

METHODS

In 6 healthy volunteers a multilumen perfusion catheter was used to generate a 20-cm isolated jejunal segment that was perfused with 80 mg verapamil. Simultaneously, 5 mg [(2)H(7)]verapamil was given intravenously. Blood, perfusate, and bile samples were analyzed for parent verapamil and its major metabolites.

RESULTS

The mean fraction of the verapamil dose absorbed from the 20-cm segment was 0.76 but substantial interindividual variability (0.51-0.96) was shown. Bioavailability was low (19.3%). The intestinal wall contributed to the same extent as the liver to extensive first-pass metabolism (mean extraction ratio, 0.49 versus 0.48). Substantial transport of verapamil metabolites from the systemic circulation via the enterocytes into the intestinal lumen was observed. Compared with biliary excretion, intestinal secretion into a 20-cm jejunal segment contributed to drug elimination to a similar extent.

CONCLUSION

First-pass metabolism by the intestinal wall is extensive and contributes to the same extent as the liver to low bioavailability of some drugs such as verapamil. Moreover, intestinal secretion is as important as biliary excretion for the elimination of metabolites.

Delayed gastric emptying in ventilated critically ill patients: measurement by 13 C-octanoic acid breath test

OBJECTIVE

To measure gastric emptying in ventilated critically ill patients with a new noninvasive breath test.

DESIGN

Single-center, open study.

SETTING

Combined medical and surgical intensive care unit of a university hospital.

SUBJECTS

Thirty unselected mechanically ventilated critically ill patients receiving gastric feeding and 22 healthy volunteers.

INTERVENTIONS

None.

PATIENTS

After 4 hrs without feeding, intragastric infusion of 100 mL of a liquid meal (Ensure) labeled with 100 microL 13C-octanoic acid. End-expiratory breath samples were collected into evacuated tubes from the respirator circuit every 5 mins for the first hour, then every 15 mins for 3 hrs. End-expiratory breath samples were also collected from volunteers studied supine after an overnight fast following an identical infusion via a nasogastric tube. Breath 13CO2 was measured with an isotope ratio mass spectrometer.

MEASUREMENTS AND MAIN RESULTS

Performance of the breath test posed no difficulty or interference with patient care. The CO2 level was >1% in 1297/1300 breath samples, indicating satisfactory end-expiratory timing. Data are median and interquartile range. Gastric emptying was slower in patients compared with volunteers: gastric emptying coefficient 2.93 (2.17-3.39) vs. 3.58 (3.18-3.79), p <.001 and gastric half emptying time, derived from the area under the 13CO2 curve, 155 min (130-220) vs. 133 min (120-145), p <.008. Fourteen of the 30 patients had a gastric emptying coefficient <95% of all volunteers and 11 had a gastric half emptying time longer than 95% of all volunteers. The Acute Physiology and Chronic Health Evaluation (APACHE II) score (median 22, range 13-43) either at admission or on the day of the study did not correlate with gastric emptying coefficient.

CONCLUSION

Gastric emptying of a calorie-dense liquid meal is slow in 40% to 45% of unselected mechanically ventilated patients in a combined medical and surgical intensive care unit. The 13C-octanoic acid breath test is a novel and useful bedside technique to measure gastric emptying in these patients.

The role of the specialist in the diagnosis and short and long term care of patients with gastroesophageal reflux disease

Advances in knowledge about reflux disease and its treatment allow a better focused discussion about cost-effective management compared to 5 yr ago. These developments also offer opportunities for patient management to be more firmly based in a primary care setting, with consequent reductions of cost. This opportunity arises from the recognition that endoscopy is an insensitive test for reflux disease, and from a more complete understanding of the treatment efficacy of proton pump inhibitors. Symptom pattern evaluation and a test of therapy with a proton pump inhibitor is now recognized as the best mainstream option for diagnosis, and is an approach that is well suited to primary care. Currently, though, specialists are more familiar with this, so there is a need for effective transfer of these strategies into primary care, along with the message that endoscopy will not show any diagnostically reliable changes in more than half of patients with troublesome reflux-induced symptoms, though it is the only reliable method for recognition of the complications of reflux esophagitis. Most patients with troublesome reflux-induced symptoms require long term management, either with antireflux surgery or with medication given daily only whenever symptoms are troublesome, or in short intermittent courses. The specialist's role in this is to advise the patient and his or her primary care doctor as to the available options for effective control of reflux disease, with due regard to the costs of the therapy and patient preference. The routine delivery of long term medical therapy should be in primary care, because there is no need for specialized testing or assessment in the course of this treatment.

Characterization of anorectal pressure and the anorectal inhibitory reflex in healthy preterm and term infants

OBJECTIVES

To evaluate anorectal motor function in healthy premature and term infants with the use of micromanometric techniques.

STUDY DESIGN

Anorectal manometry was performed in 22 healthy neonates (9 female) with a mean postmenstrual age of 32 weeks (range, 30 to 38 weeks) with a micromanometric anorectal assembly (od 2.0 mm). The assembly incorporated a 2-cm-long sleeve sensor for measurement of resting anal sphincter pressures and relaxation, and 4 sideholes recorded anal and rectal pressures. Rectal distension was performed with a latex balloon or direct air insufflation to elicit the anorectal inhibitory reflex (AR).

RESULTS

The mean anal sphincter pressure, rectal pressure, and rhythmic wave frequency were 40 mm Hg (range, 7 to 65 mm Hg), 11 mm Hg (range, 1 to 27 mm Hg), and 10/min (range, 8 to 14/min), respectively. A normal AR could be elicited in 21 of the 22 infants studied.

CONCLUSION

An anorectal micromanometric sleeve catheter is suitable for use in evaluating anorectal pressures in preterm and term neonates. Insufflation of air without the use of a balloon to elicit the AR is reliable and suitable for use in infants <34 weeks. Premature infants older than 30 weeks' postmenstrual age have normal anorectal pressures and a normal AR.

Small intestinal motor patterns in critically ill patients after major abdominal surgery

OBJECTIVES

In patients who have had major surgery or trauma, early enteral feeding is safer and more effective than parenteral or nasogastric feeding but is frequently associated with diarrhea. Limited recordings have shown that the patterning of duodenal interdigestive motor activity is frequently abnormal after surgery or in patients who are critically ill. The aims of this study were to evaluate the effects of major abdominal surgery on small intestinal motility, and to elucidate the motor patterns that occur postoperatively in critically ill patients in response to enteral feeding.

METHODS

The effects of elective aortic aneurysm repair on small intestinal motility were studied in 11 patients aged 63-77 yr. A 3.5-mm diameter multilumen extrusion was used to monitor pressures at 12 points, distributed between the antrum and 100 cm distal to the pylorus. An additional lumen allowed enteral feeding into the duodenum. Recordings commenced immediately postoperatively and continued for up to 4 days. Data are given as means and SEMs.

RESULTS

Bursts (frequency > 10/min) of small intestinal pressure waves that resembled phase III interdigestive motor activity occurred in all patients immediately after surgery. During mechanical ventilation, the timing of bursts along the segment evaluated was frequently abnormal for true interdigestive phase III activity, with simultaneous onset in multiple channels (46%), multiple or distal origins (8%), or retrograde migration (20%). When patients were not being ventilated, the migration pattern of the bursts was more typical of interdigestive phase III activity. The interval between bursts was unusually short for interdigestive motor activity, although it increased from 30+/-12 min on day 1 to 41+/-18 min on day 3 (p < 0.05). A phase II pattern of pressure waves was virtually absent in all patients on all study days. In six patients who received postoperative enteral nutrition, the bursts of pressure waves were not abolished by feeding, contrary to normal phase III activity.

CONCLUSIONS

Small intestinal pressure wave bursts are seen immediately after elective aortic aneurysm repair, but the migration of these bursts is frequently abnormal for phase III interdigestive activity. Duodenal nutrient delivery did not interrupt the occurrence of these bursts. Persistence of pressure wave bursts in this setting may be important in the delivery of enteral nutrition.

Development of a sleeve sensor for measurement of sphincter of Oddi motility

BACKGROUND AND STUDY AIMS

Unavoidable catheter movement during sphincter of Oddi (SO) manometry can produce considerable variations in the basal pressure, due to movement of the recording sidehole. The sleeve sensor is a perfused channel which records the highest pressure point along its length. The aim of the study was to develop and evaluate a prototype sleeve sensor for SO manometry.

MATERIALS AND METHODS

Bench-testing was used to assess the dynamic performance of the sleeve and sidehole assemblies. Recordings were initially made with a standard triple-lumen catheter and then with a purpose-built manometric assembly which had a 15 mm long sleeve sensor.

RESULTS

A perfusion rate of 0.04 ml/min gave the best balance between baseline pressure offset and rise rate. Recordings were attempted in nine patients and successfully achieved in four. The sleeve and sidehole recordings of the maximal basal pressure did not differ significantly (mean +/- SEM, 86.1 +/- 26.5 mmHg vs. 90.1 +/- 21.0 mmHg, P = 0.57, r = 0.998).

CONCLUSIONS

Unnecessarily high perfusion rates are being used for SO manometry. The sleeve sensor has the potential to monitor SO pressure more reliably than the currently used perfused sidehole method and should enhance the safety of prolonged SO manometry.

Relationship between ultrasonically detected phasic antral contractions and antral pressure

The relationships between gastric wall motion and intraluminal pressure are believed to be major determinants of flows within and from the stomach. Gastric antral wall motion and intraluminal pressures were monitored in five healthy subjects by concurrent antropyloroduodenal manometry and transabdominal ultrasound for 60 min after subjects drank 500 ml of clear soup. We found that 99% of antral contractions detected by ultrasound were propagated aborally, and 68% of contractions became lumen occlusive at the site of the ultrasound marker. Of the 203 contractions detected by ultrasound, 53% were associated with pressure events in the manometric reference channel; 86% of contractions had corresponding pressure events detectable somewhere in the antrum. Contractions that occluded the lumen were more likely to be associated with a pressure event in the manometric reference channel (P < 0.01) and to be of greater amplitude (P < 0.01) than non-lumen-occlusive contractions. We conclude that heterogeneous pressure event patterns in the antrum occur despite a stereotyped pattern of contraction propagation seen on ultrasound. Lumen occlusion is more likely to be associated with higher peak antral pressure events.

Relationship between straining, transient lower esophageal sphincter relaxation, and gastroesophageal reflux in children

OBJECTIVE

Physical straining such as deep inspiration or coughing may induce gastroesophageal reflux (GER) by overcoming feeble lower esophageal sphincter (LES) pressure. The role of straining as a provocant of GER has not been analyzed systematically in children. It was our aim to examine the contribution of straining to the occurrence of GER with particular attention to its relationship to transient LES relaxations, which are a major mechanism of the occurrence of GER in pediatric patients.

METHODS

Concurrent esophageal manometry and pH monitoring was performed for 4 h postprandially in six children with esophagitis (age 9 months to 12 yr). Analysis was performed on isolated single strain episodes, defined as an increased intragastric pressure > 10 mm Hg. When a drop of esophageal pH < 4.0 was noted within 15 sec after any part of a strain, this strain was defined as related to the reflux episode.

RESULTS

The median value of basal LES pressure was 10 mm Hg (range 1-18). In all, 134 analyzable strains and 87 analyzable reflux episodes were recorded. Isolated strains were associated with 20 reflux episodes (23%). Reflux was observed more frequently with strains that occurred during transient LES relaxations (12/40) than straining when the LES was contracted (8/94) (p < 0.01). Sustained strain (35%) and inspiratory strain (25%) were the major patterns of straining related to reflux.

CONCLUSION

Straining provoked reflux infrequently and simultaneous occurrence of straining and transient LES relaxation was important in determining the occurrence of strain-related reflux in pediatric patients with reflux esophagitis.

Helicobacter pylori and symptomatic relapse of gastro-oesophageal reflux disease: a randomised controlled trial

BACKGROUND

There is little information on the effects of Helicobacter pylori eradication in patients with a primary diagnosis of gastro-oesophageal reflux disease (GORD). Our aim was to investigate the effect of H pylori eradication in this group of patients.

METHODS

We did a double-blind, randomised, placebo-controlled study in 70 patients with GORD. We assigned individuals to three groups. All patients received lansoprazole 30 mg twice daily for 10 days, followed by 30 mg once daily for 8 weeks. Patients infected with H pylori received either antibiotics (clarithromycin 500 mg and amoxicillin 1000 mg twice daily) or placebo for the first 10 days. Controls were patients not infected with H pylori. Patients were followed up for 6 months at 2-week intervals for GORD symptoms. At the end of the study we repeated endoscopy and oesophageal and gastric 24 h-pH monitoring.

FINDINGS

58 of 70 patients completed our study. At the end of the study 16 of these patients were H pylori-positive (14 placebo and two eradication failures), 13 were negative because of successful H pylori eradication, and 29 were controls. H pylori-positive patients relapsed earlier (54 days) than did those in whom H pylori was eradicated (100 days) (p=0.046). The H pylori-negative control group relapsed after the longest period (110 days). However, time to relapse was also affected by oesophagitis grade (no oesophagitis 127 days, grade III or IV oesophagitis 18 days). When results were corrected for the affect of oesophagitis grade, H pylori-positive patients relapsed earlier (p=0.086) than H pylori-eradiated patients and controls (p=0.001).

INTERPRETATION

H pylori infection positively affects the relapse rate of GORD. Eradication of H pylori could, therefore, help to prolong disease-free interval in patients with GORD.

Review Article: is Helicobacter pylori relevant in the management of reflux disease?

Data on the interaction of reflux disease and Helicobacter pylori infection are limited in scope and rigour, controversial and difficult to interpret. Despite this, a framework of understanding is emerging, which is consistent with known effects on gastric acid secretion. In patients with moderate to severe H. pylori-induced corpus gastritis, eradication can increase substantially impaired gastric acid secretion sufficiently to precipitate reflux disease in people with pre-existing sub-clinical defective gastro-oesophageal competence. By contrast, reflux disease in duodenal ulcer patients probably benefits from eradication of H. pylori. There appears to be no significant impact on reflux disease from eradication in healthy subjects or individuals whose primary problem is reflux disease. Helicobacter pylori-infected reflux disease patients respond slightly better to proton pump inhibitors. These agents cause a topographic alteration of gastritis from antrum to corpus, the clinical significance of which is controversial. Many practitioners misjudge the risks and benefits of the effects of H. pylori eradication on reflux disease. Regardless of patient diagnosis, the balance is in favour of H. pylori eradication. For those in whom reflux oesophagitis development is a defined possibility, oesophagitis is mild, easily treated and most unlikely to be associated with any major risk for development of oesophageal adenocarcinoma.