Comparative analysis of phase III migrating motor complexes in stomach and small bowel using wireless motility capsule and antroduodenal manometry

Background Assessment of phase III MMC is often not performed due to the invasive nature of antroduodenal manometry used to detect it. The aim of the study was to evaluate the ability of wireless motility capsule (WMC) to detect phase III MMC and correlate it with the simultaneous measurements by antroduodenal manometry (ADM). Methods Eighteen patients underwent simultaneous ADM and WMC. MMCs were identified first on ADM and then correlated with WMC events occurring simultaneously. Frequency of contractions per min, AUC, MI, and criteria for amplitude thresholds of contractions representing MCCs on WMC tracings were defined. Key Results In 18 patients, a total of 29 MMCs were recorded by ADM. WMC detected 86% of MMC events measured by ADM. Hundred percent (10/10) of MMCs in stomach were detected by WMC, whereas 79% (15/19) of MMCs were detected in SB. The sensitivity and specificity of WMC high amplitude contractions to represent phase III MMC were 90% and 71.8% in the stomach; 73.7% and 84.7% in SB, respectively, and negative predictive value was 99.9% in both regions. Conclusions & Inferences Wireless motility capsule was able to detect the phase III MMCs as the high amplitude contractions with good fidelity. WMC does not detect the propagation of MMC. Using the pressure thresholds, WMC can detect high amplitude contraction representing phase III MMC with favorable sensitivity/specificity profile and 99.9% negative predictive value. This observation may have clinical significance, as the absence of high amplitude contractions recorded by WMC during fasting state suggests absence of MMCs.     

Gastric emptying of a non-digestible solid: assessment with simultaneous SmartPill pH and pressure capsule, antroduodenal manometry, gastric emptying scintigraphy

Abstract  Gastric emptying of digestible solids occurs after trituration of food particles. Non-digestible solids are thought to empty with phase III of the migrating motor complex (MMC). The aim of this study was to determine if a non-digestible capsule given with a meal empties from the stomach with return of the fasting phase III MMC or during the fed pattern with the solid meal. Fifteen normal subjects underwent antroduodenal manometry and ingestion of a radiolabelled meal and SmartPill wireless pH and pressure capsule. In five subjects, emptying of the SmartPill was studied in the fasting period by ingesting the SmartPill with radiolabelled water. The SmartPill emptied from the stomach within 6 h in 14 of 15 subjects. SmartPill pressure recordings showed high amplitude phasic contractions prior to emptying. SmartPill gastric residence time (261 ± 22 min) correlated strongly with time to the first phase III MMC (239 ± 23 min; r  = 0.813; P  < 0.01) and correlated moderately with solid-phase gastric emptying ( r  = 0.606 with T-50% and r  = 0.565 with T-90%). Nine of 14 subjects emptied the capsule with a phase III MMC. In five subjects, the SmartPill emptied with isolated distal antral contractions. In five subjects ingesting only water, SmartPill gastric residence time (92 ± 44 min) correlated with the time to the first phase III MMC (87 ± 30 min; r  = 0.979; P  < 0.01). The non-digestible SmartPill given with a meal primarily empties from the stomach with the return of phase III MMCs occurring after emptying the solid-phase meal. However, in some subjects, the SmartPill emptied with isolated antral contractions, an unappreciated mechanism for emptying of a non-digestible solid.     

Reproducibility of antroduodenal motility during prolonged ambulatory recording

Ambulatory recording of antroduodenal manometry is a novel technique with several advantages over standard stationary manometry recording. Although the feasibility of this technique in clinical practice has been demonstrated, reproducibility of antroduodenal motility recorded by means of ambulatory manometry has not been investigated. To test whether antroduodenal motility recorded by ambulatory manometry is reproducible, we performed two 24-h ambulatory antroduodenal manometry recordings in 18 healthy subjects according to an identical protocol with a 1-week interval. Motility was recorded with a five-channel solid-state catheter. Postprandial motility was recorded after consumption of two test meals and interdigestive motility was recorded nocturnally. Postprandial antroduodenal motor characteristics were identical between the separate recordings. The number and duration of nocturnal cycles of the interdigestive migrating motor complex were also in the same range. Phase III characteristics in general were not different between the two recordings. Only minor alterations were observed in the duration of phase III motor fronts with duodenal onset and in the number of interdigestive cycles concluded by duodenal onset phase III. Parameters obtained by qualitative analysis were comparable between the two recordings. The antroduodenal motility pattern, when measured by ambulatory recording with solid state catheters under standardized conditions, is very reproducible.     

Motility of the antroduodenum in healthy and gastroparetics characterized by wireless motility capsule

Background The wireless motility capsule (WMC) measures intraluminal pH and pressure, and records transit time and contractile activity throughout the gastrointestinal tract. Our hypothesis is that WMC can differentiate antroduodenal pressure profiles between healthy people and patients with upper gut motility dysfunctions. This study aims to analyze differences in the phasic pressure profiles of the stomach and small intestine in healthy and gastroparetic subjects. Methods Data from 71 healthy and 42 gastroparetic subjects were analyzed. The number of contractions (Ct), area under the pressure curve and motility index (MI = Ln (Ct *sum amplitudes +1)) were analyzed for 60 min before gastric emptying of the capsule (GET), (gastric window) and after GET (small bowel window) and results between groups were compared with the Wilcoxon rank sum test. Key Results Significant differences were observed between healthy and gastroparetic subjects for Ct and MI (P < 0.05). Median values of the motility parameters in gastric window were Ct = 72, MI = 11.83 for healthy and Ct = 47, MI = 11.12 for gastroparetics. In the small bowel, median values were Ct = 144.5, MI = 12.78 for healthy and Ct = 93, MI = 12.12 for gastroparetics. Diabetic subjects with gastroparesis showed significantly lower Ct and MI compared with healthy subjects in both gastric and small bowel windows while idiopathic gastroparetic subjects did not show significant differences. Conclusions & Inferences The WMC is able to differentiate between healthy and gastroparetic subjects based on gastric and small bowel motility profiles.     

Distention of the colon is associated with initiation of propagated contractions in children

Abstract  The presence of high-amplitude propagating contractions (HAPCs) has been identified as a marker of colonic neuromuscular integrity. The physiologic mechanisms of HAPCs initiation have yet to be determined. Distention secondary to colonic filling has been hypothesized as physiologic initiator. The aim of this study was to study the effect of intraluminal balloon distention in the colon of children with defecatory disorders. Colonic manometry was performed with a polyethylene balloon situated at the proximal end of the catheter, which was placed in the most proximal colonic segment reached during colonoscopy. A stepwise pressure controlled distention of the balloon was performed using barostat computer (10–50 mmHg). Propagated contractions were defined as those that migrated over at least three recording sites. They were divided into HAPCs, amplitude >60 mmHg and low-amplitude propagating contractions (LAPCs), amplitude <60 mmHg. Children with spontaneous HAPCs or HAPCs after bisacodyl provocation were considered to have normal motility. Twenty children completed the study. Among the 14 children with normal colonic motility, balloon distention elicited HAPCs in four and LAPCs in 10 children. No HAPC were elicited in six children with abnormal motility and LAPCs were seen in four of them. The balloon-induced propagated contractions had similar characteristics as those occurring spontaneously and after bisacodyl provocation but the pressure needed to elicit them and their amplitude was inconsistent. These findings suggest that intraluminal distention can trigger propagated contractions in children. This mechanism of action for induction of propagated contractions is not as consistent as the motor response found in response to bisacodyl administration.     

Ileal manometry in children following ileostomies and pull-through operations

Our aim was to analyse the patterns of ileal contractions in children. We reviewed the charts of 23 children who had ileal manometry studies (16 males), mean age 7 years (range 2 months to 17 years). We positioned the manometry catheters with 4-8 recording sites, 5 or 15 cm apart, through ileostomies fashioned for clinically indicated reasons. We studied six additional children with persistent faecal soiling following endorectal pull through for Hirschsprung's disease; the catheters were positioned through the anus and colon into the ileum. We recorded phasic and tonic intermittent contractions in all the subjects, clustered contractions (rate 5-9 min-1, duration 20-120 s) in 19 subjects with ileostomies and four with endorectal pull throughs. In 13 children there were prolonged propagated contractions, > 60 mmHg in amplitude, > 15 s in duration, propagating at rates of 2-6 cm s-1 over at least 20 cm. The migrating motor complex was rare; in 55 h of fasting recording there were two phase III sequences. There are four distinctive features of ileal manometry recordings in children: random intermittent contractions, clustered contractions, prolonged propagated contractions and tonic contractions. The features of ileal motility differ from motility in the proximal small bowel.     

Functional association between proximal and distal gastric motility during fasting and duodenal nutrient stimulation in humans

A functional integration exists between proximal and distal gastric motor activity in dogs but has not been demonstrated in humans. To determine the relationship between proximal and distal gastric motor activity in humans. Concurrent proximal (barostat) and distal (antro-pyloro-duodenal (APD) manometry) gastric motility were recorded in 10 healthy volunteers (28 +/- 3 years) during (i) fasting and (ii) two 60-min duodenal infusions of Ensure((R)) (1 and 2 kcal min(-1)) in random order. Proximal and APD motor activity and the association between fundic and propagated antral waves (PAWs) were determined. During fasting, 32% of fundic waves (FWs) were followed by a PAW. In a dose-dependent fashion, duodenal nutrients (i) increased proximal gastric volume, (ii) reduced fundic and antral wave (total and propagated) activity, and (iii) increased pyloric contractions. The proportion of FWs followed by a distal PAW was similar between both infusions and did not differ from fasting. During nutrient infusion, nearly all PAWs were antegrade, propagated over a shorter distance and less likely to traverse the pylorus, compared with fasting. In humans, a functional association exists between proximal and distal gastric motility during fasting and duodenal nutrient stimulation. This may have a role in optimizing intra-gastric meal distribution.     

Influence of sumatriptan on gastric accommodation and on antral contraction in healthy subjects assessed by ultrasonography

Background Oral sumatriptan administration has been reported to delay gastric emptying after liquid meals. The aim of this study was to determine whether delayed gastric emptying is caused by enhanced gastric accommodation, impaired antral contractions, or both using ultrasonography. Methods Ten healthy volunteers were enrolled in this randomized two‐way crossover study. After overnight fasting, the subjects received the liquid meal 60 min after ingesting a 50 mg sumatriptan tablet with 50 mL of water or 50 mL of water alone (control). The cross‐sectional area of the proximal stomach was measured in a supine position after every 100 mL. The frequency and amplitude of the antral contractions were measured in a slightly backward sitting position. The intragastric distribution of the liquid meal was assessed by calculating the proximal stomach/distal stomach ratio (prox/distal ratio). Key Results The cross‐sectional area after drinking 100, 200, and 300 mL of the liquid meal (oral sumatriptan vs control) was 34.49 vs 15.11 cm² (P = 0.0051), 48.00 vs 30.61 cm² (P = 0.0166), and 58.67 vs 47.19 cm² (P = 0.0125), respectively. There was no significant difference in the amplitude of contractions, contraction cycle, motility index, and prox/distal ratio (97.15 vs 97.93%, P = 0.0745; 19.42 vs 19.5 s, P = 0.8590; and 887.58 vs 889.22, P = 0.5751; 9.75 vs 8.41, P = 0.8785; respectively). Conclusions & Inferences Oral sumatriptan administration enhanced gastric accommodation after the ingestion of liquid nutrients, but had no significant effect on antral contractions or intragastric distribution in healthy subjects.     

Ambulatory Esophageal Manometry: Comparison of Expert and Computer-Aided Analyses

This study describes the validation of a computer program for automated analysis of ambulatory 24-hour two-channel esophageal manometry. The program's ability to characterize contractions and to calculate their duration and amplitude was validated against manual evaluation. An independent reference standard for the identification and classification of contractions was established by submitting representative recordings to a group of 14 experts in upper gastrointestinal motility; the program's ability to identify and classify contractions was then validated against the majority verdict of the experts. The results show an excellent correlation between the manual and computer evaluations of both contraction amplitude (p = 0.9957) and duration (p = 0.8241). The concordance between the experts was also excellent: 97 (72%) of 135 pressure events were classified identically by 12 or more experts. Computer-aided manometry analysis (CAMA) had a sensitivity of 98.9% and a specificity of 93.5% for the detection of contractions, with sensitivities of 94.7% and 84.4% and specificities of 94.9% and 94.2% for the classification of propagated and nonpropagated contractions, respectively.     

Gastric motor disturbances in patients with idiopathic rapid gastric emptying

Background The mechanisms of ‘idiopathic’ rapid gastric emptying, which are associated with functional dyspepsia and functional diarrhea, are not understood. Our hypotheses were that increased gastric motility and reduced postprandial gastric accommodation contribute to rapid gastric emptying. Methods Fasting and postprandial (300 kcal nutrient meal) gastric volumes were measured by magnetic resonance imaging (MRI) in 20 healthy people and 17 with functional dyspepsia; seven had normal and 10 had rapid gastric emptying. In 17 healthy people and patients, contractility was analyzed by spectral analysis of a time‐series of gastric cross‐sectional areas. Logistic regression models analyzed whether contractile parameters, fasting volume, and postprandial volume change could discriminate between health and patients with normal or rapid gastric emptying. Key Results While upper gastrointestinal symptoms were comparable, patients with rapid emptying had a higher (P = 0.002) body mass index than normal gastric emptying. MRI visualized propagating contractions at ～3 cpm in healthy people and patients. Compared with controls (0.32 ± 0.04, Mean ± SEM), the amplitude of gastric contractions in the entire stomach was higher (OR 4.1, 95% CI 1.2–14.0) in patients with rapid (0.48 ± 0.06), but not normal gastric emptying (0.20 ± 0.06). Similar differences were observed in the distal stomach. However, the propagation velocity, fasting gastric volume, and the postprandial volume change were not significantly different between patients and controls. Conclusions & Inferences MRI provides a non‐invasive and refined assessment of gastric volumes and contractility in humans. Increased gastric contractility may contribute to rapid gastric emptying in functional dyspepsia.     

GLP-1 regulates gastroduodenal motility involving cholinergic pathways

Abstract  The gut-born incretin hormone glucagon-like peptide-1 (GLP-1) delays gastric emptying. To elucidate the mechanisms by which GLP-1 affects gastroduodenal motility and glycaemia, we studied the effects of exendin(9–39), a potent GLP-1 receptor antagonist, on gastroduodenal motility and pancreatic hormones. In this randomized, double-blind, placebo-controlled, four-arm, cross-over trial, 10 healthy volunteers were studied during the interdigestive period followed by duodenal perfusion of a mixed liquid meal (250 kcal). On four separate days, exendin(9–39), atropine, exendin(9–39) + atropine or saline were infused intravenously. Antro-pyloro-duodenal and fundic motility were assessed. The compliance of the proximal stomach was determined by isobaric distensions. During fasting, exendin(9–39) did not influence proximal gastric volume, pyloric tone, and duodenal contractility. Exendin(9–39) significantly increased antral waves only in the absence of atropine. During duodenal meal perfusion, exendin(9–39) significantly reduced proximal gastric volume accommodation, abbreviated postprandial antral inhibition, reduced the postprandial increase in pyloric tone, and reduced gastric compliance. Atropine abolished the effects of exendin(9–39) on gastric volume accommodation but did not affect its effects on postprandial antroduodenal motility and on gastric compliance. Exendin(9–39) increased fasting and postprandial glycaemia and plasma glucagon but not insulin concentrations. Atropine did not affect GLP-1 secretion. Cholinergic mechanisms mediate the effects of GLP-1 on postprandial gastric accommodation but not on antro-pyloro-duodenal motility. GLP-1 reduces fasting and postprandial glycaemia, in part by reducing glucagon secretion.     

Multiple rapid swallowing: a complementary test during standard oesophageal manometry

Abstract  Multiple rapid swallowing (MRS) stimulates neural inhibition resulting in abolition of contractions in the oesophageal body (OB) and complete lower oesophageal sphincter (LOS) relaxation which is followed by peristalsis and LOS contraction. The aim of this study was to evaluate the yield of MRS to detect abnormalities in inhibitory or excitatory oesophageal mechanisms in patients with oesophageal symptoms and either normal standard manometry or ineffective oesophageal motility (IOM). MRS (five water swallows, 2 mL, separated by 2–3 s) was evaluated in 23 healthy subjects, 109 symptomatic patients with normal standard sleeve manometry and in 48 patients with IOM. Healthy subjects had complete inhibition of OB motility during MRS and a strong motor response after MRS, i.e. amplitude of OB contractions in the oesophageal body and LOS tone being higher than after single swallows. Almost 70% of patients with oesophageal symptoms and normal manometry had abnormal MRS, mainly consistent on inability to increase amplitude of OB contractions after MRS. Nearly, half of the patients with IOM were able to normalize OB contractions after MRS. MRS is a simple complementary test that can be added to standard oesophageal manometry. Two-thirds of patients with normal manometry show abnormal MRS that could potentially underlie their symptoms. A normal response to MRS in patients with severe IOM might be used to predict response to prokinetic treatment.     

Real‐time visualization of altered gastric motility by magnetic resonance imaging in patients with Parkinson's disease

Gastrointestinal motility is frequently affected in Parkinson's disease (PD) and has even been reported in early stages of PD. We hypothesized that gastric motility can be assessed in vivo by real‐time magnetic resonance imaging (MRI), an established, noninvasive method. After an overnight fast and a standardized test meal, 10 patients with PD (six drug naïve, four treated) and 10 healthy volunteers underwent real‐time MRI scanning of the stomach. Gastric motility was quantified by calculating the gastric motility indices (GMI) from transversal oblique und sagittal oblique MRI scans. There was a trend toward a decreased gastric motility in patients with PD compared with healthy controls (Mann‐Whitney test, P 0.059). This difference in peristalsis was due to a significant reduction in the amplitude of peristaltic contractions (P 0.029) and not to a decelerated velocity of the peristaltic waves (P 0.97). Real‐time MRI allows direct visualization of gastric motility in PD. In this pilot study, a relatively high interindividual variability impaired accurate separation of our PD sample from healthy controls. The trend toward decreased gastric motility is in accordance with previous studies that investigated gastric motility in patients with PD using other methods. Our study provides first demonstration of a possible underlying mechanism for disturbed gastric motility in PD (reduced amplitude of contractions versus altered velocity of peristaltic waves). Further studies in drug‐naïve PD patients are required to determine the discriminatory power and validity of this technique in PD. © 2010 Movement Disorder Society     

Low antroduodenal pressure gradients are responsible for gastric emptying of a low-caloric liquid meal in humans

The motor mechanisms responsible for transpyloric flow of gastric contents are still poorly understood. The aim of our study was to investigate the relationship between luminal pressures and gastric wall motion and between gastroduodenal pressure gradients and pressure waves, and ante- and retro-grade transpyloric flow. In eight healthy volunteers, intraluminal pressures were recorded from the antrum and proximal duodenum. Transpyloric flow was monitored simultaneously using duplex ultrasonography, before, during and after ingestion of 300 mL meat soup. Transpyloric emptying occurred as sequences of alternating periods of emptying-reflux-emptying. Approximately one-third of the sequences were not associated with peristalsis. The antroduodenal pressure gradients were significantly lower during nonperistaltic-related emptying than during peristaltic-related emptying (0.15 (0-0.3) kPa, and 1.7 (0.2-2.0) kPa, respectively [mean plus minus (range)], P < 0.005). The duration of emptying episodes not associated with peristalsis were significantly longer than those associated with peristalsis at (6.5 (3-8.7) s and 4.4 (2-6) s, respectively, P=0.059). Manometry detected only 56% of the antral contractions seen on ultrasound. We concluded that gastric emptying of a low-calorie liquid meal occurs both during peristaltic and nonperistaltic antral activity. In spite of lower antroduodenal pressure gradients, the emptying episodes were longer for nonperistaltic emptying, which is likely to be caused by low pyloric resistance. Considerable flow seems to occur without peristalsis during gastric emptying of a low-calorie, liquid meal in humans.     

Gastrointestinal motor activity associated with postoperative ileus and emesis

The gastrointestinal motor activity associated with post-operative ileus and emesis has not been fully elucidated. This study has evaluated gastric and small-bowel motility in six patients before and after cholecystectomy and in six healthy volunteers, by solid-state manometry. Nausea and vomiting were recorded post-operatively. After surgery, fasting motor abnormalities including (a) total gastric quiescence and (b) small-bowel ‘phasic-bursts’ of contractions were observed in all patients. Phasic bursts (PB) resembled phase III of the migrating motor complex (MMC) on initial visual inspection, but further analysis revealed that they were of shorter duration (3.4 ±.2 min [PB] vs 6.4 ± 0.8 min [MMC], [mean ± SEM] P < 0.01), lower contraction frequency (6.4 ± 0.1 contractions min ^?1 [PBj vs 10 ± 0.3 contractions min^?1 [MMC] [mean ± SEM] P < 0.01) and shorter periodicity (36.4 ± 3 min [PB] vs 70.0 ± 6 min [MMC] [mean ± SEM] P < 0.01). Four patients experienced nausea during phasic burst activity. Vomiting was only observed in association with retrograde phasic-bursts, which migrated through the duodenum to the stomach. This study has shown consistent gastrointestinal motor abnormalities in the immediate post-operative state.     

High amplitude propagated contractions

While most colonic motor activity is segmental and non‐propulsive, colonic high amplitude propagated contractions (HAPC) can transfer colonic contents over long distances and often precede defecation. High amplitude propagated contractions occur spontaneously, in response to pharmacological agents or colonic distention. A subset of patients with slow transit constipation have fewer HAPC. In this issue of Neurogastroenterology and Motility, Rodriguez et al. report that anal relaxation during spontaneous and bisacodyl‐induced HAPC exceeds anal relaxation during rectal distention in constipated children undergoing colonic manometry. Moreover, and consistent with a neural mechanism, anal relaxation often precedes arrival of HAPC in the left colon. High amplitude propagated contractions are also used to evaluate the motor response to a meal and pharmacological stimuli (e.g., bisacodyl, neostigmine) and to identify colonic inertia during colonic motility testing in chronic constipation. This editorial comprehensively reviews the characteristics, physiology and pharmacology of HAPC, their assessment by manometry, and relevance to constipation and diarrhea.     

Gastric Electrical Stimulation on Gastric Motility in Dogs

Aims: The aim of this study was to systematically evaluate and compare the effects of synchronized dual‐pulse gastric electrical stimulation (SDPS) and conventional gastric electrical stimulation (CGES) on antral contractions, gastric tone, and autonomic functions. Methods: Seven female hound dogs implanted with four pairs of electrodes on gastric serosa were studied in two separate experiments. The first experiment was designed to investigate the effects of SDPS/CGES on gastric tone and heart rate variations. The second experiment was performed to study the effects of SDPS/CGES on antral contractions. Results: 1) SDPS induced gastric antral contractions in the fasting state, whereas CGES at the intrinsic or a tachygastrial frequency had no effects on fasting antral contractions. 2) SDPS enhanced postprandial antral contractions impaired by glucagon; however, CGES at a tachygastrial frequency inhibited postprandial antral contractions. In addition, CGES at the intrinsic frequency of the stomach had no effects on postprandial antral contractions. 3) SDPS or CGES at the intrinsic frequency of the stomach had no effects on gastric tone, but CGES at a tachygastrial frequency reduced gastric tone. 4) SDPS excited vagal activity, but CGES at a tachygastrial frequency inhibited vagal activity. Conclusions: SDPS improves antral contractions but does not affect gastric tone and thus may have potential for treating gastric motility disorders. CGES at a tachygastrial frequency inhibits gastric tone and contractions and may be applicable for treating obesity. The excitatory or inhibitory effects of SDPS/CGES on gastric motility may be mediated via vagal pathway.     

Ghrelin regulates gastric phase III-like contractions in freely moving conscious mice

Abstract  In humans and dogs, motilin regulates phase III contractions of migrating motor complex (MMC) in the interdigestive state, while ghrelin regulates MMC in rats. It still remains unclear whether ghrelin regulates phase III contractions of the mouse stomach. A miniature strain gauge transducer was sutured on the antrum to detect circular muscle contractions and gastric contractions of the interdigestive state were evaluated. Effects of ghrelin, a ghrelin receptor antagonist, and atropine on spontaneous gastric contractions were studied in freely moving conscious mice. Similar to the rat stomach, phase III-like contractions were observed in the interdigestive state, which disappeared immediately after the feeding. Ghrelin augmented spontaneous phase III-like contractions, while growth-hormone secretagogue receptor antagonists and atropine abolished the occurrence of spontaneous phase III-like contractions. The spontaneous phase III-like contractions were no more observed in vagotomized mice. These results suggest that ghrelin regulates phase III-like contractions in mice stomach via its own receptors. Ghrelin-induced gastric phase III-like contractions are mediated via vagal cholinergic pathways in mice. Our recording system of mice gastric motility may be useful to study the functional changes in gene knockout mice, in the future.     

Interobserver variability in antroduodenal manometry

Abstract  Interobserver variability affects investigations involving assessment of complex visual data, such as histopathology, radiology and motility. This study assessed interobserver variation for interpretation of antroduodenal manometry (ADM), as this has not been previously investigated. Thirty-five ADM recordings from children aged 0.3–18 years were independently evaluated by five experienced paediatric gastroenterologists who were blinded to cases' clinical histories. Intra-class correlation (ICC) was analysed for detection and measurement of phase three of the migrating motor complex (MMC) and Cohen's kappa statistic was calculated between observer pairs for detection of specific motility features and final diagnosis. Observers were unanimous on the differentiation of normal and abnormal motility in 63% of cases. There was excellent interobserver agreement for the number of phase three of the MMC in fasting (ICC = 0.82, P  < 0.0001) and for measurements of phase three of the MMC (ICC = 0.9999, P  < 0.0001). Detection of other normal and abnormal motility patterns varied more. Objective findings such as the presence of phase three of the MMC correlated more closely than findings that involved the integration of several variables, such as final diagnosis. However, these data overall indicate that agreement between expert observers for the distinction of normal and abnormal antroduodenal motility compares favourably with other standard medical assessments.