The effect of endoscopic mucosal resection and transanal endoscopic microsurgery on anorectal function.

AIM: The study assessed the impact on anorectal function of endoscopic mucosal resection (EMR) and transanal endoscopic microsurgery (TEM) of large rectal adenomas. METHOD: Patients with a large (≥ 3 cm) rectal adenoma undergoing EMR or TEM were included. Self-reported faecal incontinence was assessed using the Colorectal Functional Outcome (COREFO) questionnaire and the Wexner Incontinence Grading Scale. Anorectal manometry was performed before and at 6 months after treatment to measure anal resting (ARP) and squeeze pressure (SP), squeeze endurance (SE), the rectoanal inhibitory reflex (RAIR), rectal volumetry of first sensation (FS), first urge (FU), maximum tolerable volume (MTV) and rectal compliance (RC). RESULTS: Twenty-four patients were included in the study, of whom 11 underwent EMR and 13 underwent TEM. The mean adenoma size was 51 ± 19 mm and the median distance from the anal verge was 3 cm (interquartile range 1-10 cm). Follow-up data were available from 20 patients; one patient had died and three had undergone total mesorectal excision. Incontinence for liquid stool and Wexner score decreased significantly after treatment. In contrast, none of the measured parameters of anorectal motility (ARP, SP, SE, RAIR, RC) and perception (FS, FU, MTV) was affected by adenoma resection. No differences were found in baseline and follow-up incontinence and functional parameters between intervention groups, except for postprocedural ARP, which was lower after TEM than after EMR. CONCLUSION: Continence in patients with a large rectal adenoma improved after EMR or TEM, probably due to decreased rectal mucus production. Anal sphincter pressure, rectoanal reflexes, rectal sensation and compliance were not affected by adenoma resection.

Rapid drinking challenge during high-resolution manometry is complementary to timed barium esophagogram for diagnosis and follow-up of achalasia.

BACKGROUND: Esophageal stasis is a hallmark of achalasia. Timed barium esophagogram (TBE) is used to measure stasis but exposes patients to ionizing radiation. It is suggested that esophageal stasis can be objectified on high-resolution manometry (HRM) as well using a rapid drinking challenge test (RDC). We aimed to assess esophageal stasis in achalasia by a RDC during HRM and compare this to TBE. METHODS: Thirty healthy subjects (15 male, age 40 [IQR 34-49]) and 90 achalasia patients (53 male, age 47 [36-59], 30 untreated/30 treated symptomatic/30 treated asymptomatic) were prospectively included to undergo HRM with RDC and TBE. RDC was performed by drinking 200 mL of water. Response to RDC was measured by basal and relaxation pressure in the esophagogastric junction (EGJ) and esophageal pressurization during the last 5 seconds. KEY RESULTS: EGJ basal and relaxation pressure during RDC were higher in achalasia compared to healthy subjects (overall P < .01). Esophageal body pressurization was significantly higher in untreated (43 [33-35 mm Hg]) and symptomatic treated patients (25 [16-32] mm Hg) compared to healthy subjects (6 [3-7] mm Hg) and asymptomatic treated patients (11 [8-15] mm Hg, overall P < .01). A strong correlation was observed between esophageal pressurization during RDC and barium column height at 5 minutes on TBE (r = .75, P < .01), comparable to the standard predictor of esophageal stasis, IRP (r = .66, P < .01). CONCLUSIONS & INFERENCES: The RDC can reliably predict esophageal stasis in achalasia and adequately measure treatment response to a degree comparable to TBE. We propose to add this simple test to each HRM study in achalasia patients.

Reflux and Belching after Laparoscopic 270 degree Posterior Versus 180 degree Anterior Partial Fundoplication.

BACKGROUND: Laparoscopic 270 degree posterior, or Toupet (LTF), and 180 degree anterior partial fundoplication (LAF) ensure equal reflux control and reduce the risk of gas-related symptoms compared to 360 degree (Nissen) fundoplication. It is unclear which type of partial fundoplication is superior in preventing gas-related side-effects. The aim of this study was to determine differences in effect of LTF and LAF on reflux characteristics and belching patterns. METHODS: Upper gastrointestinal endoscopy, esophageal manometry, and 24-h combined pH-impedance monitoring were performed before and 6 months after fundoplication (n = 10, LTF vs. n = 10, LAF). Observed changes after surgery (∆) were compared between the two procedures. RESULTS: Symptomatic reflux control as well as the reduction in the mean number of acid (∆ - 58.5 vs. - 66.5; P = 0.912), liquid (∆ - 17.0 vs. - 43.5; P = 0.247), and mixed liquid gas reflux episodes (∆ - 38.0 vs. - 40.0; P = 0.579) were comparable following LTF and LAF. There were no differences in the mean number of weakly acidic reflux episodes after LTF and LAF (1.0 (0.8-4) vs. 1.0 (0-3), P = 0.436). The reduction in proximal (P = 1.000), mid-esophageal (P = 0.063), and distal reflux episodes (P = 0.315) was comparable. Both procedures equally reduced the number of gastric belches (P = 0.278) and supragastric belches (P = 0.123), with no significant reduction in the number of air swallows after either procedure (P = 0.278). CONCLUSION: LTF and LAF provide similar reflux control, with a comparable effect on acidic, liquid, and gas reflux. Both procedures equally reduced the number of belches and supragastric belches. This study provides the physiological evidence for the published randomized trials reporting similar symptomatic outcome after both types of partial fundoplication.

Objectively diagnosing rumination syndrome in children using esophageal pH-impedance and manometry.

BACKGROUND: Rumination syndrome is characterized by recurrent regurgitation of recently ingested food into the mouth. Differentiation with other diagnoses and gastroesophageal reflux disease (GERD) in particular, is difficult. Recently, objective pH-impedance (pH-MII) and manometry criteria were proposed for adults. The aim of this study was to determine diagnostic ambulatory pH-MII and manometry criteria for rumination syndrome in children. METHODS: Clinical data and 24-hour pH-MII and manometry recordings of children with a clinical suspicion of rumination syndrome were reviewed. Recordings were analyzed for retrograde bolus flow extending into the proximal esophagus. Peak gastric and intraesophageal pressures closely related to these events were recorded and checked for a pattern compatible with rumination. Events were classified into primary, secondary, and supragastric belch-associated rumination. KEY RESULTS: Twenty-five consecutive patients (11 males, median age 13.3 years [IQR 5.9-15.8]) were included; recordings of 18 patients were suitable for analysis. Rumination events were identified in 16/18 patients, with 50% of events occurring <30 minutes postprandially. Fifteen of 16 patients showed ≥1 gastric pressure peak >30 mmHg, while only 50% of all events was characterized by peaks >30 mmHg and an additional 20% by peaks >25 mmHg. Four patients had evidence of acid GERD, all showing secondary rumination. CONCLUSIONS AND INFERENCES: Combined 24-hour pH-MII and manometry can be used to diagnose rumination syndrome in children and to distinguish it from GERD. Rumination patterns in children are similar compared with adults, albeit with lower gastric pressure increase. We propose a diagnostic cutoff for gastric pressure increase >25 mmHg associated with retrograde bolus flow into the proximal esophagus.

Intra- and interrater reliability of the Chicago Classification of achalasia subtypes in pediatric high-resolution esophageal manometry (HRM) recordings.

BACKGROUND: Subtyping achalasia by high-resolution manometry (HRM) is clinically relevant as response to therapy and prognosis have shown to vary accordingly. The aim of this study was to assess inter- and intrarater reliability of diagnosing achalasia and achalasia subtyping in children using the Chicago Classification (CC) V3.0. METHODS: Six observers analyzed 40 pediatric HRM recordings (22 achalasia and 18 non-achalasia) twice by using dedicated analysis software (ManoView 3.0, Given Imaging, Los Angeles, CA, USA). Integrated relaxation pressure (IRP4s), distal contractile integral (DCI), intrabolus pressurization pattern (IBP), and distal latency (DL) were extracted and analyzed hierarchically. Cohen's κ (2 raters) and Fleiss' κ (>2 raters) and the intraclass correlation coefficient (ICC) were used for categorical and ordinal data, respectively. RESULTS: Based on the results of dedicated analysis software only, intra- and interrater reliability was excellent and moderate (κ=0.89 and κ=0.52, respectively) for differentiating achalasia from non-achalasia. For subtyping achalasia, reliability decreased to substantial and fair (κ=0.72 and κ=0.28, respectively). When observers were allowed to change the software-driven diagnosis according to their own interpretation of the manometric patterns, intra- and interrater reliability increased for diagnosing achalasia (κ=0.98 and κ=0.92, respectively) and for subtyping achalasia (κ=0.79 and κ=0.58, respectively). CONCLUSIONS: Intra- and interrater agreement for diagnosing achalasia when using HRM and the CC was very good to excellent when results of automated analysis software were interpreted by experienced observers. More variability was seen when relying solely on the software-driven diagnosis and for subtyping achalasia. Therefore, diagnosing and subtyping achalasia should be performed in pediatric motility centers with significant expertise.

Diagnostic yield of 24-hour esophageal manometry in non-cardiac chest pain.

BACKGROUND: In the past, ambulatory 24-h manometry has been shown useful for the evaluation of patients with non-cardiac chest pain (NCCP). With the diagnostic improvements brought by pH-impedance monitoring and high-resolution manometry (HRM), the contribution of ambulatory 24-h manometry to the diagnosis of esophageal hypertensive disorders has become uncertain. Our aim was to assess the additional diagnostic yield of ambulatory manometry to HRM and ambulatory pH-impedance monitoring in this patient population. METHODS: All patients underwent 24-h ambulatory pressure-pH-impedance monitoring and HRM. Patients had retrosternal pain as a predominant symptom and no explanation after cardiologic and digestive endoscopic evaluations. Diagnostic measurements were analyzed by two independent physicians. KEY RESULTS: Fifty-nine patients met the inclusion criteria; 37.3% of the patients had their symptoms explained by abnormalities on pH-impedance monitoring and 6.8% by ambulatory manometry. Functional chest pain was diagnosed in 52.5% of the patients. High-resolution manometry, using the Chicago Classification v3.0 criteria alone, did not identify any of the four patients with esophageal spasm on ambulatory manometry. However, taking into account other abnormalities, such as simultaneous (rapid) or repetitive contractions, HRM had a sensitivity of 75% and a specificity of 98.2% for the diagnosis of esophageal spasm. CONCLUSIONS & INFERENCES: In the work-up of NCCP, ambulatory 24-h manometry has a low additional diagnostic yield. However, it remains the best technique to identify esophageal spasm as the cause of symptoms. This is particularly useful when an unequivocal diagnosis is needed before treatment.

Distal esophageal spasm and the Chicago classification: is timing everything?

BACKGROUND: According to the Chicago classification of esophageal motility disorders, distal esophageal spasm (DES) is defined as premature esophageal contractions (distal latency [DL] <4.5 s) for ≥20% of swallows, in the presence of a normal mean integral relaxation pressure (IRP). However, some patients with symptoms of DES have rapid contractions with a normal DL. The aim of this study was to characterize these patients and compare their clinical characteristics to those of patients classified as DES. METHODS: We retrospectively compared clinical characteristics and high-resolution manometry findings of patients with rapid contractions with normal latency to those meeting the Chicago classification criteria for DES. KEY RESULTS: Over a 3-year period, nine patients were diagnosed with DES and 14 showed rapid contractions in the distal esophagus with normal latency. The latter were younger than DES patients (60 ± 4 vs 72 ± 3 years, p < 0.05). Dysphagia and retrosternal pain occurred to a similar degree in both groups. Weight loss and abnormal barium esophagogram tended to be more frequent in DES patients. There was no difference in contractile front velocity (CFV) and in distal contractile integral (DCI) between patients with DES and rapid contractions with normal latency. Lower esophageal sphincter pressures were not different between groups. However, IRP was significantly higher in DES compared to rapid contractions with normal latency (11.7 ± 0.6 mmHg vs 7.6 ± 1.2 mmHg, p < 0.05), albeit still within the normal range. CONCLUSIONS & INFERENCES: These data suggest that patients with simultaneous contractions with normal latency represent a group of patients with many features similar to DES.

Assessment of bolus transit with intraluminal impedance measurement in patients with esophageal motility disorders.

BACKGROUND: The clinical management of patients with non-obstructive dysphagia is notoriously difficult. Esophageal impedance measurement can be used to measure esophageal bolus transit without the use of radiation exposure to patients. However, validation of measurement of bolus transit with impedance monitoring has only been performed in healthy subjects with normal motility and not in patients with dysphagia and esophageal motility disorders. The aim was, therefore, to investigate the relationship between transit of swallowed liquid boluses in healthy controls and in patients with dysphagia. METHODS: Twenty healthy volunteers and 20 patients with dysphagia underwent concurrent impedance measurement and videofluoroscopy. Each subject swallowed five liquid barium boluses. The ability of detecting complete or incomplete bolus transit by means of impedance measurement was assessed, using radiographic bolus transit as the gold standard. KEY RESULTS: Impedance monitoring recognized stasis and transit in 80.5% of the events correctly, with 83.9% of bolus transit being recognized and 77.2% of stasis being recognized correctly. In controls 79.8% of all swallows were scored correctly, whereas in patients 81.3% of all swallows were scored correctly. Depending on the contractility pattern, between 77.0% and 94.3% of the swallows were scored correctly. CONCLUSIONS & INFERENCES: Impedance measurement can be used to assess bolus clearance patterns in healthy subjects, but can also be used to reliably assess bolus transit in patients with dysphagia and motility disorders.

Normal values of esophageal motility after antireflux surgery; a study using high-resolution manometry.

BACKGROUND: Fundoplication is an effective therapy for gastroesophageal reflux disease (GERD), but can be complicated by postoperative dysphagia. High-resolution manometry (HRM) can assess esophageal function, but normal values after fundoplication are lacking. Our aim was to obtain normal values for HRM after successful Toupet and Nissen fundoplication. METHODS: Esophageal HRM was performed 3 months after Toupet or Nissen fundoplication in 40 GERD patients without postoperative dysphagia and with a normal barium esophagogram. Normal values for all measures of the Chicago classification were calculated as 5th and 95th percentile ranges. KEY RESULTS: The normal values (5th-95th percentiles) for integrated relaxation pressure (IRP) were higher after Nissen (5.1-24.4 mmHg) than after Toupet fundoplication (3.1-15.0 mmHg), and upper limit of normal was significantly higher after Nissen fundoplication than observed in the asymptomatic subjects that were described in the Chicago Classification. Distal contractile integral was significantly higher after Nissen (357-4947 mmHg*s*cm) than after Toupet (68-2177 mmHg*s*cm), and transition zone length was significantly shorter after Nissen (0-4.8 cm) than after Toupet fundoplication (0-12.8 cm). CONCLUSIONS & INFERENCES: HRM metrics for subjects after a Toupet fundoplication are similar to the normal values derived from healthy subjects used for the Chicago classification. However, after Nissen fundoplication a higher esophagogastric junction resting pressure and higher IRP are observed in asymptomatic subjects and this can be considered normal in the postoperative state. In addition, more vigorous contractions and less and smaller peristaltic breaks are normal after Nissen fundoplication.

Sensation of stasis is poorly correlated with impaired esophageal bolus transport.

BACKGROUND: It is common belief that symptoms of patients with non-obstructive dysphagia are the result of impaired bolus clearance in the esophagus, usually caused by esophageal motility disorders. We therefore investigated the relationship between transit of swallowed boluses and the symptom dysphagia. METHODS: Twenty healthy volunteers and 20 patients with dysphagia underwent videofluoroscopy. Success of bolus transport was graded on a 7-point scale. Each subject swallowed five liquid and five solid barium boluses. KEY RESULTS: For liquids, patients reported dysphagia during 1 [0-3] of the five swallows, while controls reported no dysphagia (median 0 [0-0]; p = 0.003). For solids, patients reported dysphagia during 3 [2-4] of five swallows, while controls reported dysphagia in 0.5 [0-2] of five swallows (p = 0.001). When correlating dysphagia to ineffective clearance (score ≥ 3), in 3 [2-4] of five liquids, the subjects perception of clearance was related to the clearance result on fluoroscopy in patients and also 3 [1-5] were correctly perceived in controls (p = 0.6). For solids, in 4 [3-5] of five swallows, the subjects perception of clearance was related to the clearance result on fluoroscopy in patients, but only 2 [1-3] of five swallows were correctly perceived by controls, the difference being statistically significant. CONCLUSIONS & INFERENCES: Patients very frequently report dysphagia when bolus clearance is successful. Therefore, the major underlying problem in patients with non-obstructive dysphagia is disordered perception and increased sensitivity to physiological bolus stasis. Treatment should therefore be directed at reducing increased sensitivity rather than at improving motility.

Prucalopride decreases esophageal acid exposure and accelerates gastric emptying in healthy subjects.

BACKGROUND: The 5-HT4 receptor agonist prucalopride is a prokinetic drug which improves colonic motility. Animal data and in vitro studies suggest that prucalopride also affects gastric and esophageal motor function. We aimed to assess the effect of prucalopride on gastric emptying, esophageal motility, and gastro-esophageal reflux in man. METHODS: In this double-blind, placebo-controlled, randomized, crossover study, we included 21 healthy volunteers who received 4 mg prucalopride or placebo per day for 6 days. We performed high-resolution manometry (HRM) followed by 120-min HRM-pH-impedance monitoring after a standardized meal, ambulatory 24-h pH-impedance monitoring, and gastric emptying for solids. KEY RESULTS: Prucalopride decreased (median [IQR]) total acid exposure time (3.4 [2.5-5.6] vs 1.7 [0.8-3.5] %, p < 0.05). The total number of reflux events was unaffected by prucalopride, however, the number of reflux events extending to the proximal esophagus was reduced by prucalopride (15.5 [9.8-25.5] vs 10.5 [5.3-17.5], p < 0.05). Furthermore, prucalopride improved acid clearance time (77.5 [47.8-108.8] vs 44.0 [30.0-67.8] s, p < 0.05). Prucalopride did not affect the number of transient lower esophageal sphincter (LES) relaxations or their association with reflux events. Esophageal motility and basal pressure of the LES were not affected by prucalopride. Prucalopride increased gastric emptying (T1/2 ; 32.7 [27.9-44.6] vs 49.8 [37.7-55.0] min, p < 0.05) and decreased residue after 120 min (8.8 [4.4-14.8] vs 2.7 [1.3-5.4] %, p < 0.05). CONCLUSIONS & INFERENCES: Prucalopride reduces esophageal acid exposure and accelerates gastric emptying in healthy male volunteers. These findings suggest that the drug could be effective for treatment of patients with reflux disease and functional dyspepsia.

Impact of spatial resolution on results of esophageal high-resolution manometry.

BACKGROUND: The Chicago classification for esophageal motility disorders was designed for a 36-channel manometry system with sensors spaced at 1 cm. However, many motility laboratories outside the USA use catheters with a lower resolution in the segments outside the esophagogastric junction. Our aim was to investigate the effect of spatial resolution on the Chicago metrics and diagnosis. METHODS: In 20 healthy volunteers and 47 patients with upper gastrointestinal symptoms, high-resolution manometric studies of the esophagus were retrospectively reanalyzed using the original 1-cm spacing in the segments outside the 7-cm esophagogastric junction segment, and again after manually increasing the spacing between sensors to 2, 3, and 4 cm (above the lower esophageal sphincter region). Measurements were analyzed in random order and the investigator was blinded to the outcome of the analyses performed in another resolution of the same patient. Intra-class correlation coefficients (ICC) and Kappa values were determined. KEY RESULTS: There was a very strong correlation between the 1-cm and 2-cm analysis for all Chicago metrics studied in healthy volunteers (ICCs: distal contractile integral 0.998; contractile front velocity (CFV) 0.964; distal latency 0.919; peristaltic break size 0.941). The 2-cm spacing analysis also correlated very well with the 1-cm analysis for the different Chicago diagnoses obtained in the patients (Kappa values ranging from 0.665 to 1.000). When the sensor spacing was increased to 3 and 4 cm, the correlation was reduced to moderate for the Chicago metrics, especially for break size and CFV of peristalsis. CONCLUSIONS & INFERENCES: The Chicago classification for esophageal motility disorders is still valid and the same normal values can be used when catheters with a slightly lower resolution are used (i.e., 2-cm vs 1-cm spacing). For larger sensor intervals, the classification and the normal values will need to be adjusted.

Normal values for esophageal high-resolution manometry.

BACKGROUND: Esophageal high-resolution manometry (HRM) is a novel method to assess esophageal motility. Several software and hardware systems are currently available. A set of normal values for HRM parameters was established in the US, using proprietary tactile-sensing catheter technology (Given Imaging). We wished to determine normal values for HRM performed with another type of catheter (Unisensor). METHODS: Fifty-two healthy volunteers underwent supine HRM. Each subject swallowed 10 liquid water boluses. Esophageal contraction parameters were evaluated and normal values were calculated (defined as 5th and 95th percentile of values). KEY RESULTS: The normal range for the following parameters was calculated; distal contractile integral (mean 1319.44, with a 5-95th percentile range [185.65-3407.60]), contractile front velocity (mean 3.98, 5-95th percentile range [2.40-6.50]), Intrabolus pressure (mean 9.68, range [1.00-19.00]), contraction amplitude measured 5 cm above the esophagogastric junction (EGJ; mean 78.76, range [23.00-146.00]), contraction amplitude 15 cm above the EGJ (mean 43.66, range [3.60-96.00]), transition zone (TZ) length (mean 1.34, range [0.00-5.63]), upper esophageal sphincter (UES) pressure (mean 81.63, range [19.50-165.10]), EGJ length (mean 2.97, range [2.17-4.00]), EGJ resting pressure (mean 29.35, range [8.95-51.40]), EGJ relaxation pressure (mean 16.79, range [1.00-39.35]), IRPs4 (mean 13.42, range [2.59-28.28]), and gastric pressure (mean 5.06, range [0.00-9.46]). CONCLUSIONS & INFERENCES: Overall, the normal values of esophageal HRM parameters obtained with the Unisensor catheter resemble those of the previously published series. Marked differences in upper limits of normal were found for parameters related to the esophageal sphincters and TZ length. Users of HRM should be aware of these differences and define pathology based on comparison to appropriate normal values.

Relationship between esophageal contraction patterns and clearance of swallowed liquid and solid boluses in healthy controls and patients with dysphagia.

BACKGROUND: Non-obstructive dysphagia patients prove to be a difficult category for clinical management. Esophageal high-resolution manometry (HRM) is a novel method, used to analyze dysphagia. However, it is not yet clear how findings on HRM relate to bolus transport through the esophagus. METHODS: Twenty healthy volunteers and 20 patients with dysphagia underwent HRM and videofluoroscopy in a supine position. Each subject swallowed five liquid and five solid barium boluses. Esophageal contraction parameters and bolus transport were evaluated with HRM and concurrent videofluoroscopy. KEY RESULTS: Stasis of liquid and solid barium boluses occurred in patients and in healthy volunteers in 64% and 41% and in 84% and 82% of the swallows, respectively. Overall, 70% of the liquid and 72% of the solid bolus swallows were followed by a peristaltic contraction, the difference not being statistically significant. Statistically significant associations were found for transition zone length of liquid and solid boluses, and for DCI and distal contraction amplitudes for liquid stasis. No correlation was found between the degree of stasis and other manometric parameters. CONCLUSIONS & INFERENCES: Stasis of both liquid and solid boluses occurs frequently in patients and in controls and can be regarded as physiological. Motility patterns can predict the effectiveness of bolus transit and level of stasis to some degree but the relationship between esophageal motility and transit is complex and far from perfect. Esophageal manometry is therefore currently deemed unfit to be used for the prediction of bolus transit, and should rather be used for the identification of treatable esophageal motility disorders.

Duodenal lipid-induced symptom generation in gastroesophageal reflux disease: role of apolipoprotein A-IV and cholecystokinin.

BACKGROUND: Duodenal lipid intensifies the perception of esophageal acid perfusion. Recently, we showed that genes implicated in lipid absorption were upregulated in the duodenum of fasting gastro-esophageal reflux disease (GERD) patients. This suggests that chylomicron production and secretion may be enhanced and, consequently, the release of apolipoprotein A-IV (apoA-IV), a chylomicron-derived signaling protein. ApoA-IV may stimulate release of cholecystokinin (CCK), an activator of vagal afferents. This study evaluated putative involvement of abnormal apoA-IV and CCK responses to lipid in GERD. METHODS: Ten GERD patients and 10 healthy volunteers (HV) underwent duodenal perfusion with Intralipid 20%, 2 kcal min(-1) , for 60 min. Symptoms were scored, blood samples collected every 15 min during lipid perfusion and 15 min after discontinuation when duodenal biopsies were taken. Plasma and mucosal concentrations of apoA-IV and CCK and transcript levels of 21 genes implicated in lipid absorption, differentially expressed under fasting conditions, were quantified. KEY RESULTS: Heartburn (P = 0.003), abdominal discomfort (P = 0.037) and nausea (P = 0.008) only increased significantly during lipid infusion in GERD patients. Following lipid infusion mean mucosal apoA-IV concentration was lower in GERD patients compared with HV (P = 0.023), whereas plasma concentration tended to be elevated (P = 0.068). Mean mucosal CCK concentration was also lower in GERD patients (P = 0.009). Two genes, HIBADH and JTB, were upregulated in GERD patients (P = 0.008 and P = 0.038, respectively). CONCLUSIONS & INFERENCES: Our results suggest excessive duodenal lipid-induced release of apoA-IV and CCK in GERD. We postulate that the resulting heightened activation of duodenal vagal afferents may underlie central sensitization, thereby increasing the perception of reflux events.

Reproducibility of esophageal high-resolution manometry.

BACKGROUND: Esophageal high-resolution manometry (HRM) is a novel method for esophageal function testing that has prompted the development of new parameters for quantitative analysis of esophageal function. Until now, the reproducibility of these parameters has not been investigated. METHODS: Twenty healthy volunteers underwent HRM on two separate days. Standard HRM parameters were measured. In addition, in conventional (virtual) line tracings, lower esophageal sphincter (LES) resting pressure, relaxation pressure, and relative relaxation pressure were measured. Firstly, for each variable, the mean percentage of covariation (100×SD/mean: %COV) was derived as a measure of inter- and intra-individual variation. Secondly, Kendall's coefficients of concordance (W values) were calculated. Thirdly, Bland-Altman plots were used to express concordance graphically. KEY RESULTS: Statistically significant concordance values were found for upper esophageal sphincter (UES) pressure (W=0.90, P=0.02), transition zone length (W=0.92, P=0.01), LES length (W=0.81, P=0.04), LES pressure (W=0.75, P=0.05), LES relaxation pressure (W=0.75, P=0.03), relative LES relaxation pressure (W=0.78, P=0.05), gastric pressure (W=0.81, P=0.04), and contraction amplitude 5cm above the LES (W=0.86, P=0.03). In conventional setting, only LES resting pressure (W=0.835, P=0.03) proved significant. In HRM tracings, concordance values for contraction wave parameters, and in conventional line tracings, LES relaxation pressure and relative relaxation pressure did not reach levels of statistical significance. CONCLUSIONS & INFERENCES: Esophageal HRM yields reproducible results. Parameters that represent anatomic structures show better reproducibility than contraction wave parameters. The reproducibility of LES resting and relaxation pressure assessed with HRM is better than with conventional manometry and further supports the clinical use of HRM.

Impaired bolus transit across the esophagogastric junction in postfundoplication dysphagia.

OBJECTIVES: This study assessed the effect of fundoplication on liquid and solid bolus transit across the esophagogastric junction (EGJ) in relation to EGJ dynamics and dysphagia. METHODS: Twelve patients with gastro-esophageal reflux disease (GERD) were studied before and after fundoplication. Concurrent high-resolution EGJ manometry and fluoroscopy were performed whilst swallowing liquid barium and a solid bolus. The EGJ transit time, EGJ opening duration, transit efficacy, and EGJ relaxation were measured. During the test symptoms of dysphagia were scored using a visual analog scale. RESULTS: The minimal opening aperture at fluoroscopy was located at the manometric EGJ in all subjects. Fundoplication markedly reduced the EGJ opening diameter from 1.0 +/- 0.1 to 0.6 +/- 0.1 cm (p < 0.01) and rendered deglutative EGJ relaxation incomplete. After fundoplication, a higher intrabolus pressure was found (p < 0.05) associated with a reduced axial bolus length (p < 0.001). EGJ transit time increased from 6.9 +/- 0.9 to 9.8 +/- 1.0 s for liquids (p < 0.01) and from 2.8 +/- 0.5 to 5.8 +/- 0.8 s (p < 0.01) for solids after fundoplication. No relation between EGJ transit and dysphagia scores was observed before fundoplication. In contrast, EGJ transit time significantly correlated with dysphagia scores both during liquid (r = 0.84; p < 0.01) and solid (r = 0.69; p < 0.05) bolus transit following fundoplication. CONCLUSIONS: Fundoplication patients exhibit a restricted hiatal opening and an incomplete deglutative EGJ relaxation. To facilitate EGJ transit despite these altered EGJ dynamics a higher intrabolus pressure is created by augmented bolus compression. Fundoplication increases EGJ transit time, the degree of which is associated with postoperative dysphagia.

Interdigestive transpyloric fluid transport assessed by intraluminal impedance recording.

Our aim was to explore the use of intraluminal impedance recording for assessment of interdigestive transpyloric fluid movements. Twenty healthy volunteers were studied with a catheter allowing the recording of five antropyloroduodenal impedance signals simultaneously with six pressure signals. Patterns induced by air were verified by standard ultrasound. Transpyloric Doppler ultrasound was used to validate impedance patterns associated with transpyloric fluid transports. Impedance changes caused by air (short-lived increases) occupied 14 +/- 12% of the time in the antrum and 0.8 +/- 0.5% in the duodenum (P < 0.005). All fluid transport events lasting >4 s were recorded by both Doppler and impedance techniques. Transpyloric fluid transport was observed in all three phases of the antral migrating motor complex. The total number of transport events was significantly higher (P < 0.05) in phase II (18 +/- 7) than in phases I (2.6 +/- 2) and III (6.1 +/- 3). Retrograde transport was observed mainly in antral phase I (54% of fluid movements, compared with 2.5% in phase II and 18.5% in phase III, P < 0.05). During phase II, 80 +/- 13% of the impedance changes were associated with manometric events and 72 +/- 9% of the antral contractions were associated with transpyloric fluid transport. Prolonged assessment of interdigestive transpyloric fluid transport events using intraluminal measurement of impedance is possible. Manometrically detectable contractions are the most frequent, but not the only, driving forces of these events.