Emptying Curves Research Articles

Measurement of gastric emptying and gastric motility by magnetic resonance imaging (MRI)

Hitherto it has been impossible to measure noninvasively gastric emptying and motility from multiple regions of the stomach in humans. We describe the development of a novel methodology to achieve this using magnetic resonance imaging (MRI). Initial validation studies performed in five healthy volunteers demonstrated similar gastric emptying curves and secretion rates after ingestion of 10% dextrose labeled with [Gd]DOTA, assessed by MRI ([Gd]DOTA as meal marker) and a simultaneous double-indicator technique. Comparison between MRI and scintigraphy in five patients also gave similar results. Application of newer MRI technology allowing a series of coronal scans 1.2 sec apart permitted quantification of wall motion in the proximal and distal stomach in seven healthy volunteers. These results indicate that MRI provides new insights into the mechanisms responsible for both normal and disordered emptying.

Detection of gastroesophageal reflux by electrical impedance tomography.

In children with vomiting, dyspepsia, and feeding problems, gastroesophageal reflux (GOR) and altered gastric emptying are common. We have used electrical impedance tomography (EIT) to study children with suspected gastric emptying disorders. Abnormalities of the gastric emptying curve suggestive of GOR were seen in some, with marked negative or positive shifts related to sharp increases or decreases in intragastric resistance. These findings could represent fluid leaving or entering the stomach, as might occur in GOR. To confirm the origin of the abnormal EIT curves, we devised and in vitro tank test system, and we performed simultaneous 2-h EIT and intraoesophageal pH monitoring after a glucose meal on six patients. In vitro, reflux of > or = 25 ml produced clearly detectable changes on the emptying curves. In vivo, the overall correlation between the times of 42 GOR episodes lasting > or = 1 min detected by pH study and the times of 38 negative peaks due to > or = 15% changes of the maximum intragastric resistivity detected by simultaneous EIT was significant; the correlation was highly significant in four of six patients. When the peaks were used to define GOR episodes on EIT gastric emptying curves, the two methods still showed good agreement. Retrospective examination of 50 patients who had undergone both EIT and 24-h intraoesophageal pH study during their diagnostic workup showed that EIT had a sensitivity of 94.6% and a specificity of 76.9% (with positive and negative predictive values of 0.92 and 0.83, respectively) for the detection of pathological GOR.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of Gastroesophageal Reflux by Electrical Impedance Tomography

SummaryIn children with vomiting, dyspepsia, and feeding problems, gastroesophageal reflux (GOR) and altered gastric emptying are common. We have used electrical impedance tomography (EIT) to study children with suspected gastric emplying disorders. Abnormalities of the gastric emptying curve suggestive of GOR were seen in some, with marked negative or positive shifts related to sharp increases or decreases in intragastric resistance. These findings could represent fluid leaving or entering the stomach, as might occur in GOR. To confirm the origin of the abnormal EIT curves, we devised and in vitro tank test system, and we performed simultaneous 2‐h EIT and intraoesophageal pH monitoring after a glucose meal on six patients. In vitro, reflux of ±25 ml produced clearly detectable changes on the emptying curves. In vivo, the overall correlation between the times of 42 GOR episodes lasting ±1 min detected by pH study and the times of 38 negative peaks due to ±15% changes of the maximum intragastric resistivity detected by simultaneous EIT was significant; the correlation was highly significant in four of six patients. When the peaks were used to define GOR episodes on EIT gastric emptying curves, the two methods still showed good agreement. Retrospective examination of 50 patients who had undergone both EIT and 24‐h intraoesophageal pH study during their diagnostic workup showed that EIT had a sensitivity of 94.6% and a specificity of 76.9% (with positive and negative predictive values of 0.92 and 0.83, respectively) for the detection of pathological GOR. We have shown, for the first time that EIT not only allows gastric emptying to be measured but can also detect GOR. Therefore, EIT can be used as a noninvasive screening test in patients with vomiting, dyspepsia, and feeding problems.

Effects of highly selective vagotomy and additional procedures on gastric emptying in patients with obstructing duodenal ulcer.

A solid gastric emptying study was conducted on 46 patients more than 1 year after highly selective vagotomy (HSV) and additional procedures for obstructing duodenal ulcer and on 21 patients after HSV alone for uncomplicated duodenal ulcer. The additional procedures included dilatation (n = 14; HSV + D group), Holle pyloroplasty (n = 14; HSV + P group), and Jaboulay gastroduodenostomy (n = 18; HSV + GD group). The test meal consisted of two eggs labeled with 99mTc sulfur colloid, two slices of white bread toast, and 300 ml of orange juice (total 322 kcal). Gastric emptying curves and emptying parameters (t1/2, half emptying time; lag phase, TLAG; emptying rate, k; and beta value) were compared with those of 17 healthy volunteers, the normal control group. The patients after HSV alone had an almost normal gastric emptying. The HSV + D group showed a significant delay from minute 45 to the end of the emptying curve, corresponding to a longer t1/2 (p = 0.02), and a slower emptying rate (p = 0.029). The HSV + P group approached a nearly normal emptying curve, corresponding to an insignificant difference in emptying parameters. The HSV + GD group had significantly faster emptying from minute 15 to the end of the emptying curve, corresponding to a faster t1/2 (p = 0.0005), a shorter lag phase (p = 0.027), and a faster emptying rate (p = 0.021). Recurrent ulcerations were noted in one patient (4.8%) of the HSV alone group, five (35.7%) of the HSV + D group, one (7.1%) of the HSV + P group, and one (5.6%) of the HSV + GD group.(ABSTRACT TRUNCATED AT 250 WORDS)

Out line of measurement of gastric emptying using by radioisotope and its problems awaiting solution

The radioisotopic technique has been recognized as the best method of measuring gastric emptying all over the world, but several problems which must be solved have remained in it. The first is the confusion in the choice of a standard meal of ordinary food labeled with radioisotope. A meal for use in this studies must be reproducible in quality, and radioisotope must be homogenously distributed in it. It is necessary to consider the efficiency of examination, and to release a examinee's agony, therefore a meal must leave the stomach within the tolerable limits of a patient who keeps himself unshaken during measurement. If a liquid meal is used, we can easily make use of foods on the market. But, if a solid meal, a practical difficulty stands in front of us; Who prepares to cook it? Unless this problem has been solved, the radioisotopic method is never found general acceptance as a clinical examination. The second is the confusion in the choice of a posture during measurement. We must select such posture that never alter a patient's characteristics of his gastric emptying. For example, it is difficult to prove rapid evacuation in a patient with dumping syndrome, if we examine him in supine position. A final problem is to re-examine what kinds of index are necessary to investigate the gastric emptying curve with many variations except of half-emptying time which has been used popularly as the index of the rate of it. We gave an out-line of the methods of measuring gastric emptying using radioisotope and a suggestion of its some problems awaiting solution.

Ultrasonography and gastric emptying: evaluation in infants with gastroesophageal reflux.

We have applied ultrasonography to the evaluation of gastric emptying in children. Two different populations have been investigated: normal children and children with gastroesophageal reflux. All the patients were less than 6 months of age. The diagnosis of gastroesophageal reflux was defined by 24-h pH measurement. The technique, used to measure gastric emptying, is the one described by Bolondi et al. In this research we used the simplified method. All children had been submitted to the examination after 4-h fasting. The standard meal was the usual milk formula, 300 ml/m2 body surface area (BSA). A cross-section area of the gastric antrum was determined before a meal and every 15 min for 2 h. The examination was concluded after two measurements were equal to the basal one. The normal gastric emptying curve was determined by a control group. Patients with gastroesophageal reflux showed three different kind of gastric emptying: (a) normal gastric emptying in 20% of cases, (b) abnormal gastric emptying in 15% of cases, and (c) intermediate cases in which the plateau curve is abnormal but the end time of gastric emptying is normal. We defined these three kinds of curves as type I or normal, type III or abnormal, and type II or intermediate. The estimate of frequency in patients with gastroesophageal reflux is similar to the reported data of the literature.

Ultrasonography and Gastric Emptying

We have applied ultrasonography to the evaluation of gastric emptying in children. Two different populations have been investigated: normal children and children with gastroesophageal reflux. All the patients were <6 months of age. The diagnosis of gastroesophageal reflux was defined by 24‐h pH measurement. The technique, used to measure gastric emplying, is the one described by Bolondi et al. In this research we used the simplified method. All children had been submitted to the examination after 4‐h fasting. The standard meal was the usual milk formula, 300 ml/m2 body surface area (BSA). A cross‐section area of the gastric antrum was determined before a meal and every 15 min for 2 h. The examination was concluded after two measurements were equal to the basal one. The normal gastric emptying curve was determined by a control group. Patients with gastro‐esophageal reflux showed three different kind of gastric emptying: (a) normal gastric emptying in 20% of cases, (b) abnormal gastric emptying in 15% of cases, and (c) intermediate cases in which the plateau curve is abnormal but the end time of gastric emptying is normal. We defined these three kinds of curves as type I or normal, type III or abnormal, and type II or intermediate. The estimate of frequency in patients with gastroesophageal reflux is similar to the reported data of the literature.

Dietary restriction delays gastric emptying in rats

In rats allowed to eat for only 2 h per day, gastric emptying of three different meals [poached egg white, glucose (0.5 kcal/ml) and physiological saline, each labelled with 60 MBq of technetium- 99m tin colloid visualized using a gamma camera] was markedly slowed 8 h after the last meal. Mean body weight in rats on the restricted feeding schedule was 80% of the weight of free-feeding controls. Gastric emptying curves for all three meals in controls were best described using log e transformed counts. Other models used were linear and square root. For each of the three meals, the percentage remaining in the stomach at 120 min was estimated using linear regression of gastric contents, transformed if necessary to yield the best curve against time. At 120 min, % gastric contents (mean±SEM) were 19.5 ± 5.6 (egg), 15.5 ± 6.27 (glucose) and 27.1 ± 7.48 (saline) in control rats. After 4 months restriction, the corresponding figures were 75.2 ± 4.04, 81.5 ± 4.75 and 70.3 ± 5.83. After 3 months of free feeding, emptying rates of the three meals were not significantly different from control values. We conclude that dietary restriction causes profound changes in gastric emptying by unknown mechanisms which may be operating in patients with anorexia nervosa.

Effects of cisapride on gastric emptying.

To evaluate the effects of cisapride on gastric emptying, gastric emptying was measured in six healthy volunteers using radioisotopic techniques which were established three areas of interest, i.e. the whole stomach, the proximal stomach and the antrum. Following results were obtained. 1. At the half emptying times, cisapride induced a more rapid gastric emptying than did placebo in 5 of 6 volunteers. 2. By analyzing gastric emptying curves obtained from three areas of interest, it was suggested that cisapride enhanced the transfer of gastric contents from the proximal stomach to the antrum together with the antral emptying, so that gastric emptying was accelerated.

Physical characteristics of indigestible solids affect emptying from the fasting human stomach.

Gastric emptying of indigestible solids depends on their size. It is not clear whether physical characteristics other than particle size affect emptying of indigestible solids from the fasting human stomach. We studied gastric emptying of three differently shaped particles, (cubes, spheres, rods) of either hard or soft consistency during the fasting state in human volunteers. The shape of indigestible particles did not affect their emptying. The area under the gastric emptying curve (AUC: particles x hour) was for hard cubes 24.7 (2.2), for hard spheres 27.9 (1.6), for hard rods 26.9 (2.7). All soft particles emptied faster than their identically shaped hard counterparts, but there was no difference among the three shapes (AUC for soft cubes: 29.2 (3.0), for soft spheres 32.0 (1.8), for soft rods 34.1 (1.2). If gastric emptying of hard and soft particles was compared independently of their shape, soft particles emptied significantly faster than hard ones: AUC 31.8 (1.2) v 26.5 (1.3) (p less than 0.01). In conclusion, the consistency but not the shape significantly affects gastric emptying. Specific physical characteristics other than size and shape may affect gastric emptying of indigestible particles which may be of importance in the design of drugs.

Comparative analysis of quantitative gastric emptying indices and power-exponential modelling of gastric emptying curves.

A comparative study was undertaken on the problems of choosing a reliable measure of gastric emptying (GE). The study was based on 218 GE measurements of a radiolabelled solid meal. Power-exponential fitting of GE curves was shown to provide an excellent mathematical approximation to experimental data - a coefficient of determination r2 greater than equal to 0.90 was obtained in the case of 96.3% GE curves. A range of indices was derived from the data, namely, the time to reach the maximum of a GE curve, the area under a GE curve, the mean transit time (and mean transit time during the ninety minutes of the examination), the emptying index, the GE half-time t 1/2 and the shape factor S. On the basis of between-subject variability (3.9% coefficient of variation) and reproducibility (coefficient of variation for paired examinations, CVp = 3.2%), the mean transit time calculated over the period of the GE study (MTT90) was found to be the best GE measure. The versatility of the power-exponential method was confirmed by the analysis of mathematical curves designed to mimic a range of real life emptying patterns, and the relationships between the derived parameters were also investigated.

Small bowel resistances and the gastroduodenal brake.

Osmoreceptors in the upper small bowel may delay gastric emptying by inhibiting fundal tone and/or by increasing outflow resistances. In this study we examined the contribution of postpyloric resistances to this braking system. Seven dogs had gastric emptying of 250 ml 15% dextrose, labelled with 99mTc-DTPA, measured by gamma camera imaging (preoperative studies: n = 21). A proximal duodenal cannula was inserted and studies repeated in four modes: with the cannula closed (n = 14); with total diversion of gastric effluent through the cannula (n = 7); with diversion and downstream reinstillation of effluent at a constant rate (n = 14) equivalent to emptying calculated from studies without diversion; and with diversion and total reinstillation of effluent (n = 14). Gastric emptying at 90 minutes was similar in preoperative studies (48 +/- 5% - mean +/- SEM) and in those with the cannula closed (50 +/- 3%). By comparison 'total diversion' produced rapid emptying over 90 minutes (97 +/- 1%; p less than 0.001). Reinstillation of effluent at a constant rate reduced the 90 minute emptying to 59 +/- 6%, and total reinstillation slowed emptying further to 37 +/- 4% (p less than 0.05). Neither reinstillation protocol yielded gastric emptying rates that were significantly different from those in studies without diversion. With total reinstillation, emptying and hence reinstillation rates were more variable, proceeding in a step and plateau fashion. We conclude that canine jejunal osmoreceptor activity is mediated through the stomach, with postpyloric resistances playing little or no role. Gastric emptying curve analysis suggested that increments of rapid small bowel filling provoke exaggerated braking responses.

Background does not Significantly Affect Power-Exponential Fitting of Gastric Emptying Curves

Using a procedure enabling the assessment of background radiation research was done to elucidate the course of changes in background activity during gastric emptying measurement. Attention was focused on the changes in the shape of power-exponential fitted gastric emptying curves after correction for background was performed. The observed pattern of background counts allowed to explain the shifts of the parameters characterizing power-exponential curves connected with background correction. It was concluded that background had a negligible effect on the power-exponential fitting of gastric emptying curves.

The relationship between gastric emptying of semisolids and paracetamol absorption.

The relationship between gastric emptying rate of semisolid Tc-99m labelled Chelex-100 resin/oatmeal and paracetamol absorption was determined simultaneously in seven healthy volunteers. There was no significant correlation between the half-time of gastric emptying and the time of the peak serum paracetamol concentration. There was no significant correlation between the area under the serum paracetamol concentrations at 60 and 90 min and the % meal emptied in 60 and 90 min respectively. Three subjects showed a lag phase in gastric emptying pattern, while the other four showed the emptying curves without evidence of a delayed phase of emptying. Individual values of gastric emptying determined by the methods varied widely.

Long-Term Results of Thrombectomy with Temporary Arteriovenous Fistula for Ileofemoral Venous Thrombosis

Nineteen patients with acute ileofemoral venous thrombosis were subjected to thrombectomy with the addition of a temporary a-v fistula and anticoagulant treatment. At follow-up 3 years after surgery isotope phlebography disclosed more-or-less patent ileofemoral segments in 16 patients. The venous outflow capacity as estimated from venous emptying curves was normal in all but three totally occluded limbs, indicating an adequate collateral compensation. Foot volumetry demonstrated signs of venous valvular insufficiency, mainly in legs with a distal extension of the initial thrombosis; these patients complained of symptoms of post-thrombotic syndrome, which emphasizes the importance of early operation.

Pancreatic carcinoma is associated with delayed gastric emptying.

Fifteen patients with histologically confirmed pancreatic carcinoma, without evidence of gastroduodenal invasion or obstruction, were prospectively studied to determine the frequency of gastric emptying disorders as determined by a solid-phase gastric emptying study. Nine of these (60%) had gastric emptying curves more than two standard deviations below normal mean values. The majority of patients did not have symptoms of gastric stasis. Nausea and/or vomiting was present in 33% of patients with abnormal gastric emptying and in none of those with normal emptying. Abdominal and/or back pain was present in 8/9 with delayed gastric emptying and in 3/6 with normal emptying. Disordered gastric emptying did not correlate with tumor stage, histology, location, or hyperbilirubinemia. Delayed solid-food gastric emptying may be responsible for the nonspecific abdominal complaints that occur during the course of pancreatic carcinoma, although more frequently, gastroparesis exists on a subclinical level.

Background analysis and comparison of two solid food markers (DTPA and IISAM) in the measurement of human gastric emptying

Measurement of gastric emptying of a radiolabelled solid food is described. A procedure enabling the assessment of background radiation, and connected with it corrections of the parameters characterizing gastric emptying curves are discussed in detail. Considering background radiation, 99mTc-DTPA and 99mTc-HSAM are shown to be equivalent as solid meal markers in the studies of gastric emptying. Correction for background can be neglected, has the background/total count ratio been sufficiently reduced.

Effect of lidamidine hydrochloride and loperamide on gastric emptying and transit of the small intestine: A double-blind study

We performed a double-blind randomized study in 24 healthy volunteers, to evaluate the effects of two doses of lidamidine hydrochloride, loperamide, and placebo on transit of the small intestine and gastric emptying. Transit time of the small intestine was determined by measuring the rise in breath hydrogen excretion after ingestion of lactulose. Although there was a trend for prolonged intestinal transit time in both lidamidine groups, this difference was not significant compared with that in the placebo group. Loperamide significantly slowed transit when compared with placebo or lidamidine (p < 0.001). Gastric emptying was assessed by using a solidphase radiolabeled meal. Three parameters of gastric emptying were analyzed: half-emptying time, area under the gastric emptying curve, and β. Although there was a trend for a longer half-emptying time in the group that received 12 mg of lidamidine, this difference approached, but did not reach, statistical significance (p = 0.06) compared with placebo. The area under the gastric emptying curve, a potentially more sensitive parameter for measuring gastric emptying, was significantly increased in the group receiving 12 and 18 mg of lidamidine (p < 0.05) compared with the group receiving loperamide or placebo. In summary, lidamidine significantly delayed gastric emptying but had no significant effect on small bowel transit. These data suggest that the antidiarrheal properties of lidamidine are the result of enhanced absorption or inhibition of secretion of fluid and electrolytes.

A study of gastric emptying in gastric and duodenal ulcers

In the examination of gastric emptying using radioisotopic techniques, three areas of interest were established, i.e. the entire gastric, proximal gastric and antral area, and gastric emptying abnormalities in cases of gastric and duodenal ulcers and their mechanism were studied by analyzing gastric emptying curves obtained from these areas. Results were summerized as follows: In highly localized gastric ulcers at active stage, compared to healthy subjects, gastric emptying in the entire gastric area was accelerated, the movement of the contents from the proximal gastric area to the antral area was accelerated, and the movement from the proximal to the antral was greater than that from the antral to the duodenum during the first three minutes after start of the measurement. Hence, in highly localized gastric ulcers at active stage, it is believed that gastric emptying in the entire is accelerated as the movement from the proximal to the antral is accelerated. In low localized gastric ulcers at active stage, compared to healthy subjects, gastric emptying in the entire was not observed in the first minute and gastric emptying was delayed once it started, the movement from the proximal to the antral was fast as in healthy subjects in the first 17 minutes or so, and in the first seven minutes, the movement from the proximal to the antral was greater than that from the antral to the duodenum. Hence, in low localized gastric ulcers at active stage, it is believed that gastric emptying in the entire becomes delayed as the gastric emptying activity in the antral is lowered. In duodenal ulcers at active stage, compared to healthy subjects, gastric emptying in the entire was accelerated, the movement from the proximal to the antral was accelerated, and during the measurement, the movement from the antral to the duodenum was greater than that from the proximal to the antral. Hence, in duodenal ulcers at active stage, it is believed that gastric emptying in the entire is accelerated as gastric emptying ability of the entire becomes excited along with that in the proximal and antral. At healing stage, gastric emptying was found to be closer to that of healthy subjects than at active stage.

Pyloric reconstruction for severe vasomotor dumping after vagotomy and pyloroplasty.

The performance of vagotomy and pyloroplasty is followed by the occurrence of dumping symptoms in 10-30% of patients. In a few, these are severe, persistent, and refractory to dietary and medical management. Pyloric reconstruction was performed in nine patients with severe dumping symptoms. All patients were treated conservatively for at least 1 year before reconstruction. Gastric emptying studies, using a 99mTc-sulphur colloid labeled 15% dextrose, were performed before and after reconstruction in each case. All were Visik grade IV before surgery. After pyloric reconstruction, interviews were conducted by a separate clinician not involved in any management of the patients. Overall improvement was obtained in eight of nine patients. Four patients improved to Visik grade II, and four to Visik grade III. With regard to dumping symptoms only, seven of nine were improved to Visik grade II. All patients had double exponential gastric emptying curves before surgery, and six of the nine reverted to single exponential curves similar to those of unoperated controls. The initial 10-minute emptying rate was significantly decreased (p less than 0.05), and the per cent retention at 60 minutes (p less than 0.02) was significantly increased. Improvement in gastric emptying correlated well with relief of symptoms. Pyloric reconstruction is relatively simple and corrects rapid gastric emptying at the gastric outlet. These results indicate that pyloric reconstruction significantly benefits most patients with severe dumping symptoms and should be considered as the initial remedial procedure for dumping after pyloroplasty.