Wide gastric antrum in patients with non-ulcer dyspepsia. Effect of cisapride.

Fasting antral area was examined by ultrasonography in 40 healthy subjects and in 106 patients with non-ulcer dyspepsia (NUD) and erosive prepyloric changes (EPC) before and after treatment with cisapride or placebo. The patients were examined twice, first after a run-in period of 14 days of placebo and then after 14 days of cisapride, 10 mg three times daily, or placebo. The relaxed width of the antral area was measured in two sections: a vertical section in which the antrum, the superior mesenteric vein, and the aorta were visualized simultaneously, and a horizontal section that included the pylorus and the middle of the antrum up to 5 cm proximal to the pylorus. The mean antral area was wider (p less than 0.001), both in vertical and horizontal sections, in patients with NUD and EPC than in controls. The antral area in NUD patients was wider (p less than 0.05) in smokers than in non-smokers. The area tended to decrease during treatment with cisapride (p = 0.08). Bloating was the only symptom significantly associated with a wide antral area (p = 0.01). The results suggest a relationship between a wide fasting antral area and NUD with EPC.     

Longterm oral cisapride improves interdigestive antroduodenal motility in dyspeptic patients.

We have evaluated the effect of cisapride on interdigestive antroduodenal motility during a prolonged oral therapy in 20 consecutive dyspeptic subjects. Individuals with less than two migrating motor complexes (MMCs) starting from the antral region in 240 minutes and without evidence of upper gastrointestinal tract diseases were randomly treated with either cisapride (10 cases), or placebo (10 cases) for 15 days. Computerised manometry of antroduodenal region was performed for 240 minutes, in basal conditions and on the 15th day of therapy. Symptomatic evaluation of patients was also performed before and after treatment. After cisapride administration, a significant increase in the incidence of antral migrating motor complexes was noticed (p = 0.022); likewise, the motility index, calculated for phase-2 periods, appeared to be significantly higher both in the antrum and in the duodenum (p less than 0.001). Symptomatic improvement was observed in both groups, with a hardly significant (p = 0.049) reduction of dyspeptic symptoms severity only but not of frequency in cisapride treated patients v controls. We conclude that longterm oral therapy with cisapride improves interdigestive antroduodenal motor activity.     

Strenuous exercise decreases motility and cross-sectional area of human gastric antrum

Gastric emptying in humans is delayed with strenuous exercise. We used ultrasound imaging in six healthy volunteers to determine whether changes in motility and configuration of the gastric outlet contribute to this delay. After fasting, all individuals ingested chicken broth and garbanzo beans. With subjects sitting upright, transverse and longitudinal real-time views of the gastric antrum were recorded on video tape. In the exercise studies, subjects pedaled an ergometer for 10 min to attain a heart rate of 85% predicted maximum. On a different day, all subjects had an identical study without exercise. The order of performance of exercise and no-exercise studies was randomized. After exercise, contraction frequencies and antral areas were significantly reduced compared to the studies without exercise. In addition, after exercise there was closure of the pylorus and tubular narrowing of the gastric antrum. Closure of the pylorus and decreased gastric antral area and motility may be important in explaining the decrease in gastric emptying that occurs with strenuous exercise.     

Wide Gastric Antrum in Patients with Non-Ulcer Dyspepsia Effect of Cisapride

Fasting antral area was examined by ultrasonography in 40 healthy subjects and in 106 patients with non-ulcer dyspepsia (NUD) and erosive prepyloric changes (EPC) before and after treatment with cisapride or placebo. The patients were examined twice, first after a run-in period of 14 days of placebo and then after 14 days of cisapride, 10 mg three times daily, or placebo. The relaxed width of the antral area was measured in two sections: a vertical section in which the antrum, the superior mesenteric vein, and the aorta were visualized simultaneously, and a horizontal section that included the pylorus and the middle of the antrum up to 5 cm proximal to the pylorus. The mean antral area was wider (p < 0.001), both in vertical and horizontal sections, in patients with NUD and EPC than in controls. The antral area in NUD patients was wider (p < 0.05) in smokers than in non-smokers. The area tended to decrease during treatment with cisapride (p = 0.08). Bloating was the only symptom significantly associated with a wide antral area (p = 0.01). The results suggest a relationship between a wide fasting antral area and NUD with EPC.     

Relationships of human antroduodenal motility and transpyloric fluid movement: non-invasive observations with real-time ultrasound.

To study the relationships between gastric antral and proximal duodenal motor activity, and the movement of liquid across the pylorus, 10 healthy volunteers were given a test meal of dilute orange juice and bran, and events at the gastric outlet monitored by real-time ultrasound. A total of 116 complete gastric peristaltic cycles were observed and in 86% of these, associated proximal duodenal contractions were seen. Transpyloric fluid movement, as reflected by the movement of the bran particles, occurred as brief episodes during the time when the pylorus was open. Distal flow, in episodes lasting 2-4 seconds, was seen to occur in 81% of the 116 complete cycles and 75% of these episodes occurred just after the relaxation of the terminal antrum, pylorus, and proximal duodenum. The remainder occurred shortly before the terminal antral contraction. Retrograde flow, in episodes of up to 5 seconds, occurred in 78% of observed cycles with the majority occurring immediately before contraction of the terminal antrum. Our findings indicate that transpyloric fluid movement occurs in brief episodes lasting a few seconds only and that retrograde flow across the pylorus occurs in normal subjects. This pattern of fluid movement can bear no direct relationship to a steadily advancing antral peristaltic contraction, nor be wholly attributable to constant intragastric pressure.     

Timing of pyloric closure in man

The timing of pyloric closure was studied at upper alimentary endoscopy in 20 subjects without antroduodenal pathology. Antral and duodenal contractions were recorded with ballon catheters and pyloric closure detected as a fall in impedance measured across two pairs of silver wire electrodes mounted around the shaft of the duodenal catheter 0.5 cm proximal to the balloon During 300 min of good quality recording, active pyloric closure was observed on 193 occasions and 69% of closures were associated with antral or duodenal contractions within 2 sec. In 55.5% of the 154 isolated duodenal contractions (no preceding antral contraction), the pylorus, which was closed before the contraction, remained closed; in 32% the pylorus, which was open, closed within 2 sec of the contraction, while in only 12.5% was the pylorus open throughout. These observations suggest that the pylorus is able to close in response to an isolated duodenal contraction and thus may act as a barrier to duodenogastric reflux when antroduodenal contractions are not linked.     

Transpyloric fluid movement and antroduodenal motility in patients with gastro-oesophageal reflux.

The pattern of transpyloric fluid movement and associated antroduodenal motility was compared in patients with gastro-oesophageal reflux (GOR) and healthy controls using real time ultrasonic imaging. A similar number of cyclical periods of antroduodenal motor activity (GOR 94 and control 91) was studied in each group. Mean antral cycle times and the frequency of occurrence of related proximal duodenal contractions (antroduodenal coordination) were similar. Transpyloric fluid movement occurred as a number of discrete episodes in each cycle. Gastroduodenal flow was more frequent in the GOR group (mean 2.7 +/- 0.4 episodes per cycle) than in controls (mean 1.7 +/- 0.3). The mean duration of these episodes in both groups was similar at around 2.5 seconds. Duodenogastric flow (reflux) was observed in many cycles (GOR 63%; controls 54%), but there was no difference in the mean number of episodes per cycle (GOR 0.79; control 0.74) or their mean duration (two seconds for both). Transpyloric fluid flow only occurs when a pressure gradient is created across the open pylorus. These observations indicate that in GOR the gastroduodenal pressure gradient is positive more frequently than in normal controls. Gastroduodenal liquid flow but not duodenogastric reflux differs in GOR patients and controls.     

Gastric dysmotility after liquid bolus ingestion in systemic sclerosis: an ultrasonographic study

Gastric involvement appears quite commonly in systemic sclerosis (SSc). The aim of this study was to evaluate gastric wall motility using ultrasonography, a noninvasive method able to track both filling and emptying of fundus and antrum. The study was performed in 20 SSc patients and 20 healthy control subjects. Gastric filling and emptying were evaluated by transabdominal ultrasonography, measuring changes in fundus and antral areas over a 1-h period after ingestion of a liquid bolus (500 ml of mineral water). Areas of both gastric fundus and antrum at basal evaluation were found to be smaller in SSc patients than in healthy controls. Gastric filling was significantly reduced after ingestion of liquid bolus. Gastric emptying was delayed both in fundus and antrum. No significant differences of gastric wall motility have been observed in different subsets of SSc patients. Our findings show that gastric dysmotility is frequent and severe in SSc patients, contributing to the gastrointestinal disturbances which are very common in this disease.     

Motor activity of the gastric antrum, pylorus, and duodenum under fasted conditions and after a liquid meal

Because the mechanisms that control the movement of food and digestive juices across the human pylorus are not completely understood, the aim of this study was to document the normal patterns of pressure activity in the antrum, pylorus, and duodenum and the associated pH changes in 9 healthy volunteers. Studies were carried out under fasting conditions and after ingestion of 300 ml of chocolate milk, using a unique 11-channel intraluminal probe that incorporated a sleeve sensor positioned across the pylorus and pH electrodes situated in the terminal antrum and proximal duodenum. The most common motor pattern recorded under fasting conditions consisted of regular coordinated contractions, most of which (a) involved the antrum and duodenum, (b) showed evidence of propagation through two or more adjacent channels, and (c) were associated with transient reductions in duodenal pH and transient elevations in antral pH. Ingestion of milk changed the motor pattern to one that was composed of pressure waves, which were confined to the pylorus with few or no pressure waves in the terminal antrum or proximal duodenum. Isolated pyloric pressure waves were gradually replaced by propagated antroduodenal contractions, which eventually occurred at a regular frequency that was higher than that observed under fasting conditions. After ingestion of milk, only the coordinated contractions were associated with transient reductions in duodenal pH. Isolated pyloric pressure waves were also observed under fasting conditions just before or just after phase III of the migrating motor complex, and 17% of these were accompanied by episodes of duodenal acidification.     

Relation of pyloric motility to pyloric opening and closure in healthy subjects.

The relation between pyloric motor activity, opening, and closure was examined in eight healthy men. Manometry was performed with an assembly combining 13 side holes and a sleeve sensor positioned astride the pylorus. Simultaneous with manometry, pyloric opening and closure and antroduodenal contractions were observed fluoroscopically with the antrum filled with barium. During intraduodenal normal saline infusion, coordinated antral pressure waves swept over the pylorus and ejected barium into the duodenum. No localised pyloric motor pattern was observed under these conditions. In contrast, the intraduodenal triglyceride infusion was associated with the absence of antral pressure waves and virtual absence of antral wall movement. At the pylorus, there was a zone of luminal occlusion less than 1 cm long that persisted for the period of observation. This zone of luminal occlusion corresponded precisely with manometric recordings of a narrow zone of pyloric phasic and tonic activity. During the duodenal triglyceride infusion, the pylorus was closed for 98.5% of the measurement period when basal pyloric pressure was 4 mm Hg or more, and during this motor pattern, barium did not traverse the pylorus. Localised pyloric contractions cause sustained pyloric closure, whether these contractions are phasic or tonic. These contractions occur independently of antral or duodenal contractions and may interrupt gastric emptying.     

Motor mechanisms associated with slowing of the gastric emptying of a solid meal by an intraduodenal lipid infusion

The aim of this study was to define better the motor phenomena associated with the slowing of gastric emptying by a duodenal lipid infusion. Antral, pyloric and duodenal motility were recorded in 10 healthy subjects with a manometric assembly which incorporated multiple perfused side-holes and a sleeve sensor positioned astride the pylorus. The gastric emptying of a standard solid meal and the distribution of the ingesta between the proximal and distal stomach were monitored with a radionuclide technique. A triglyceride emulsion was infused into the duodenum for 45 min once 25% of the meal had emptied. The infusion caused significant slowing in the rate of gastric emptying (P less than 0.01). This slowing in gastric emptying was associated with the suppression of pressure waves in the distal antrum (P less than 0.01) and proximal duodenum (P less than 0.01), the induction of pressure waves isolated to a narrow pyloric segment (P less than 0.01), and a redistribution of ingesta from the distal to proximal stomach. These findings suggest that pressure waves isolated to the pylorus, changes in the intragastric distribution of ingested food, and changes in proximal duodenal motility may all act in concert with changes in antral motility to regulate the gastric emptying of solids.     

Malabsorption syndrome due to various causes is associated with antroduodenal hypomotility.

BACKGROUND: Patients with celiac disease who present with symptoms of gastrointestinal hypomotility have abnormal antroduodenal manometry. There are no data on antroduodenal manometry in malabsorption syndrome (MAS) due to causes other than celiac disease. METHODS: Fasting, post-prandial and post-octreotide antroduodenal motility parameters were compared in 18 untreated patients with MAS presenting with chronic diarrhea (tropical sprue 10, small bowel bacterial overgrowth 3, celiac disease 2, common variable immunodeficiency 1, AIDS with isosporidiasis and bacterial overgrowth 1, giardiasis 1) and 8 healthy subjects. RESULTS: Number of patients with MAS and controls having spontaneous migratory motor complexes (MMC) during fasting was comparable (11/18 vs 7/8; p=ns). Fasting contraction amplitude was weaker in MAS than in controls in the gastric antrum (median 42 [range 17-90] vs 80 [31-120] mmHg; p=0.001), proximal duodenum (50 [18-125] vs 72 [48-107]; p=0.013) and distal duodenum (45 [20-81] vs 76 [51-98]; p=0.001). In the fed state too, contraction amplitudes were weaker in patients with MAS in the antrum (32 [15-110] vs 76 [61-103] mmHg, p=0.002), proximal duodenum (57 [20-177] vs 73 [56-113]; p=0.07) and distal duodenum (45 [24-87] vs 75 [66-97]; p<0.0001). Patients with MAS had lower fasting and post-prandial antral and duodenal motility indices than healthy subjects. Intravenous octreotide induced MMC in all patients and controls. CONCLUSIONS: MAS due to various causes is associated with antroduodenal hypomotility typical of myopathic disorders.     

Real-time ultrasonographic assessment of antroduodenal motility after ingestion of solid and liquid meals by patients with functional dyspepsia

BACKGROUND AND AIMS: Although antroduodenal motility has usually been studied by using manometric or scintigraphic methods, ultrasonography is an established, non-invasive method to evaluate duodenogastric motility. We used ultrasonography to evaluate gastric motility in patients with functional dyspepsia. METHODS: Sixty-four patients with functional dyspepsia and 36 asymptomatic healthy subjects were given liquid and solid test meals. We investigated the gastric emptying rate, motility index, and duodenogastric reflux for the liquid meal and gastric emptying time, half-emptying time, and motility index for the solid meal. RESULTS: After the liquid meal, the gastric emptying rate and motility index were significantly lower and the duodenogastric reflux was significantly higher in functional dyspepsia patients than in healthy subjects. After the solid meal, gastric emptying time, half-emptying time and the motility index were significantly lower in the patients than in the healthy subjects. Delayed gastric emptying of both meals occurred in only 20.3% of patients. Delayed emptying of the liquid or solid meal occurred in 62.5% of patients. In both groups, gastric emptying time of the solid meal was positively correlated with the motility index at 15 min post-ingestion. CONCLUSION: In functional dyspepsia patients, delayed gastric emptying of a solid meal was related to antral hypomotility during the early postprandial phase. Ultrasonographic assessment of gastric motility in both liquid and solid meals may provide a better understanding of the pathogenesis of functional dyspepsia.     

Antroduodenal motor response to solid-liquid and homogenized meals.

The effect of the physical state of food on antroduodenal motor activity and the pattern of the emptying of an aqueous phase marker were examined in 6 healthy volunteers using an intestinal perfusion technique and intraluminal pressure transducers. Ingestion of a solid-liquid meal produced marked phasic changes in pressure in the distal antrum, lasting 92 +/- 10 min (mean +/- SE), while, in contrast, ingestion of the same nutrients in a homogenized state resulted in complete absence of distal antral changes in pressure lasting 133 +/- 12 min. The motor responses of the proximal antrum and duodenum were similar for the two meals. Both meals emptied during a 3-hr period, the pattern of emptying of the aqueous phase marker being similar for the two meals except for the first 40 min, when emptying was more rapid after the solid-liquid meal. The homogenized meal emptied despite the absence of changes in distal antral pressure. The gastrin response was similar for the two meals and is therefore not responsible for the different patterns of antral motility and gastric emptying.     

Flow across the Human Pylorus Soon after Ingestion of Food,Studied with Duplex Sonography: Effect of Glyceryl Trinitrate

Background: By means of duplex sonography, gastric emptying can be related to antral motor activity. The aim of this study was to examine gastric emptying in relation to antral contractions during and immediately after ingestion of a liquid meal in healthy subjects and to study the effect of glyceryl trinitrate (GTN) on this early phase of gastric emptying. Methods: Ten healthy, non-smoking men (median age, 36 years; range, 29-41 years) were studied twice on separate days, once without drug administration and once after taking a 0.5-mg sublingual GTN tablet 3 min before ingesting 500 ml of a meat soup (20 kcal; Toro). The subjects were investigated during 3 min of fasting, during 3 min of drinking the soup, and during the first 10 min postprandially. Results: Transpyloric forward flow commenced on average 80 sec and 95 sec after the start of drinking the soup without and with GTN, respectively (P = NS). Non-contractile, pulsatile transpyloric flow (that is, pendulating, transpyloric flow not associated with antral contractions) occurred during episodes of concurrent relaxation of the terminal antrum, the pylorus, and the duodenal bulb. This type of flow occurred mainly just before the start of contractile, pulsatile transpyloric flow (associated with propulsive antral contractions). Initial non-contractile, pulsatile transpyloric flow before commencement of contractile, pulsatile transpyloric flow lasted longer with GTN (188 sec) than without GTN (25 sec) (P &lt; 0.05). Consequently, contractile, pulsatile transpyloric flow commenced later with GTN (302 sec) than without (102 sec) (P &lt; 0.05). Conclusions: Non-contractile transpyloric flow seems to be a physiologic phenomenon during the early phase of gastric emptying. GTN prolongs the initial phase of non-contractile, and delays the onset of contractile, pulsatile transpyloric flow.     

Coordinated motor activity of the human gastroduodenal region

Using real-time ultrasonic imaging, and a test meal of 500 ml of dilute orange juice, we have studied the temporal relationships among contractions of the terminal antrum, pylorus, and proximal duodenum of 22 normal subjects. A total of 259 cyclical periods of motor activity were observed. Individual mean gastroduodenal cycle times ranged from 17.9 to 29.6 seconds (2.0–3.3 cycles/min). Terminal antral contractions (TACs) were observed 98% of cycles and pyloric closure invariably occurred at the midpoint of these contractions. The pylorus then opened as the terminal antrum relaxed and remained open until the next TAC. Only 67% of TACs were associated with contractions of the proximal duodenum (DC), but 94% of these occurred about 1 sec (range 1 sec before to 2 sec after) after pyloric closure. Only 6% of DCs were ectopic, in that their occurrence was apparently uncoordinated with the TACs. Our observations demonstrate that after ingestion of a test meal, the human terminal antrum, pylorus, and proximal duodenum usually contract in sequential coordinated manner, presumably under the control of the gastric slow wave. No evidence of independent pyloric closure was obtained.This work was supported by Scottish Home and Health Department grant K/MRS/50/C423.     

Gastric acid inhibits antral phase III activity in duodenal ulcer patients

Fourteen patients with duodenal ulcers and eight healthy volunteers were examined to measure interdigestive gastroduodenal motility and plasma motilin. In order to study the effects of gastric acid on the gastroduodenal motility, 20 mg of famotidine was administered intravenously. The motility index of the gastric antrum and the duodenum, as well as the pH in the duodenal bulb were calculated. The duodenal pH was significantly lower and the gastric motility index was significantly weaker before the duodenal interdigestive migrating complex (IMC) in the ulcer patients than in the controls. Motilin levels increased before the duodenal IMC and decreased afterwards in both groups. Famotidine significantly increased the duodenal pH and the gastric motility index before the IMC, but no changes in the motilin level were noted. We conclude that duodenal ulcer patients have duodenal hyperacidity that results from increased inflow from the antrum and antral hypomotility during the gastric IMC and that these changes are normalized by the administration of famotidine. These results suggest that gastric acid inhibits antral contraction during the gastric IMC.     

Evaluation of antral motility in humans using manometry and scintigraphy.

Recent studies suggest that scintigraphy can be used to evaluate non-invasively antral motility in humans, although scintigraphic techniques have not yet been compared with more conventional measurements of intraluminal pressures by manometry. Simultaneous scintigraphic and manometric measurements of antral motility were performed in nine healthy volunteers. After intubation with a sleeve/sidehole catheter which incorporated five pressure sideholes located at 1.5 cm intervals spanning the antrum, each subject ingested 100 g minced beef labelled with 100 MBq 99mTc-chicken liver and 150 ml water. Between 40-43, 60-63, 80-83, and 100-103 minutes after meal ingestion, radioisotopic data were acquired in two second frames. Time-activity curves showing antral 'contractions' resulting from wall motion were derived by drawing small regions of interest over the antrum to coincide with the position of the antral manometric sideholes. Scintigraphic contraction rates approximated 3/minute, whereas antral pressure waves that occluded the lumen were less frequent (p < 0.01 for all), particularly in the proximal antrum. The amplitude of wall motion, evaluated scintigraphically, and the amplitude of pressure waves were both inversely related to the distance from the pylorus (r > -0.32, p < 0.05) and antral volume r > -0.29 (p < 0.05). There were significant relationships between the amplitude of contractions assessed scintigraphically and the number of lumen-occlusive antral pressure waves in the distal antrum (r -0.48, p < 0.05) but not in the more proximal antral regions. It is concluded that scintigraphy can detect antral wall motion with greater sensitivity than manometry, particularly in the proximal antrum. As manometry gives information on the amplitude as well as the temporal and spatial organisation of those contractions which result in lumen occlusion, the combination of scintigraphic and manometric techniques in the evaluation of antral motility shows considerable promise.     

Electrogastrographic power ratio in humans is not related to changes in antrum-skin distance but to antral motility

It is not clear whether the power increase in electrogastrography (EGG) after meal or water ingestion reflects increases in gastric motility or gastric distension bringing the stomach closer to the electrodes on the abdominal skin surface. We recorded EGG and real-time ultrasonography simultaneously before and after 150-ml water ingestion in 17 healthy volunteers. We calculated gastric power, by spectral analysis of EGG by the maximum entropy method, for 400 s before and after water ingestion, and calculated their ratio (power ratio). We calculated, using sonography, the number of antral contractions before and after water ingestion, the motility index after water ingestion, the distance between the antrum and the abdominal skin surface before and after water ingestion, and the ratio of these distances (distance ratio). The number of contractions was positively correlated with gastric power before water ingestion, and the antrum-skin distance was negatively correlated with gastric power both before and after water ingestion. The motility index after water ingestion was positively correlated with both gastric power after water ingestion (Spearman's rank correlation r = 0.492; P = 0.0498) and the power ratio (r = 0.615; P = 0.0141). There was no correlation between the distance ratio and the power ratio. These results suggest that the power increase in EGG induced by water ingestion does not reflect the approach of the antrum to the abdominal surface, but rather, reflects antral motility after water ingestion. (Received June 16, 1997; accepted Nov. 28, 1997)     

Different interdigestive antroduodenal motility patterns in chronic antral gastritis with and withoutHelicobacter pylori infection

Fasting antroduodenal motor activity was studied in 15 dyspeptic patients with chronic superficial antral gastritis andHelicobacter pylori infection (group A), 10 dyspeptic patients with chronic superficial antral gastritis withoutHelicobacter pylori infection (group B), and eight healthy control subjects (group C) by manometric recording of phases of the interdigestive migrating motor complex (MMC) prolonged over 240 min. A significantly lower incidence of activity fronts (phase III of MMC) starting from the antrum was observed in patients with gastritis andHelicobacter pylori infection vs patients without bacterial colonization (P=0.013) and in these latter vs control subjects (P=0.013). Likewise, the overall number of activity fronts was smaller in patients with gastritis than in healthy subjects (P=0.034). Symptomatic evaluation was performed in the two groups of dyspeptic patients, without detecting any differences in frequency and severity of complaints. Our results show a significant reduction in the occurrence of interdigestive antral phase III of MMC in chronic gastritis associated withHelicobacter pylori infection, suggesting a possible relationship between fasting motility and bacterial colonization.