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Recent publications continue to refine the technique and interpretation of hepatobiliary scanning. Studies related to the evaluation of suspected acute cholecystitis have shown that morphine-augmented hepatobiliary imaging may not overcome the problem of false-positive study results in severely ill patients and the criterion for a normal study should be gallbladder visualization within 30 rather than 60 minutes. In patients with suspected acute cholecystitis, nonvisualized extrahepatic activity despite good hepatic uptake is highly predictive of acute cholecystitis, usually with biliary obstruction. The limitations of cholecystokinin-hepatobiliary imaging studies in patients with abdominal pain syndromes were defined and its use in evaluating common bile duct dynamics, and duodenogastric reflux was explored. Unusual findings and less-common uses of hepatobiliary scanning were reported, including assessment of conjoined twins, liver transplantation, primary biliary cirrhosis, gallbladder perforation, and persistent splenic visualization.

In 28 controls and 142 patients subjected to a variety of antiulcer procedures, the enterogastric reflux (EGR) was quantitated by 99mTc-HIDA scintigraphy and expressed as the EGR index on 229 different occasions. The EGR index was calculated according to two different formulas: one based on the maximal radioactivity over the gastric area as a percentage value of the total abdominal activity (EGR-Im) and the other based on the relative maximal radioactivity over the gastric area as a percentage value of the relative hepatobiliary activity (EGR-It). There was a significant positive correlation of values between the two methods (P less than 0.0001). In patients with an EGR-Im greater than 20% or EGR-It greater than 57% and postgastric surgery symptoms some of the symptoms were attributed to EGR, an antireflux procedure is expected to relieve those symptoms. Sixteen of these patients underwent Roux-en-Y gastrectomy and their preoperative symptoms were relieved.

To test whether the presence of gastric adenomas (dysplasia) was associated with gastric reflux of duodenal contents, six patients with familial adenomatous polyposis (FAP) who had gastric adenomas and nine matched FAP patients without gastric adenomas underwent scintigraphic duodeno-gastric reflux scanning. Reflux was graded 0-6, where 0 = no reflux, 1 = intermittent reflux into antrum only, 2 = prolonged reflux into antrum only, 3 = intermittent reflux into body, 4 = prolonged reflux into body, 5 = intermittent reflux into body and fundus, and 6 = prolonged reflux into body and fundus. FAP patients with gastric adenomas had more severe reflux (median 6, range 4-6) than did controls (median 3, range 0-6; P = 0.009, Mann-Whitney U test). These results are consistent with a role for bile in the development of gastric adenomatous polyps and suggest that bile is involved in the dysplasia-carcinoma sequence.

Enterogastric reflux occurs in normal and abnormal conditions. When pronounced, it is a nonspecific indicator of pathology. There are relatively few published reports discussing enterogastric reflux as a prominent finding on cholescintigraphy. A unique case of pronounced enterogastric reflux from an obstructing duodenal hematoma is presented.

Dumping syndrome in infancy is a rare complication following gastric surgery. We describe an 11-month-old infant affected by recurrent peptic oesophagitis who underwent a combined Nissen fundoplication and pyloroplasty. Early dumping symptoms such as irritability, pallor, sweating, abdominal distension and watery diarrhoea were observed postoperatively after bolus feeding. Gastric emptying, measured after the administration of 150 ml of regular cow milk mixed with 200 microCi (8 MBq) of technetium-99m sulfur colloid (99mTc-SC), demonstrated an early rapid and massive emptying of the isotopes into the small intestine, followed by duodenogastric reflux and a second wave of emptying and reflux at 9 min. The initial pattern of gastric emptying and duodenogastric reflux was followed by a slow emptying phase with half-emptying time of 81 min. Isotope studies should be used to investigate motility disorders caused by this type of anti-reflux operation.

Hepatobiliary scintigraphy with 99mTc-HIDA offers a noninvasive method to detect duodenogastric reflux. Biliary reflux was graded using the persistence rather than the intensity of the radioactive refluxate: Grade 0 was considered the absence of reflux, minimal reflux, or reflux in the first 10-15 min; Grade 1 was repetitive reflux lasting less than 10 min; Grade 2 was persistent reflux; and Grade 3 was reflux up to the esophagus. Twenty-five patients with foregut symptoms were studied and results were compared to 24-hr gastric pH monitoring. Scintigraphy and pH monitoring agreed in 15 out of 25 patients (60%), but no correlation was found with the endoscopic findings. The rationale for this approach is based on pathophysiologic evidence that damage to gastric and/or esophageal mucosa is mainly related to the prolonged contact time with duodenal contents. This technique seems to allow a complete functional evaluation of the esophagogastroduodenal tract without causing adjunctive irradiation or discomfort to the patient.

Qualitative indicators of dynamic hepato-biliary scintigraphy+ were studied before and after administration of cerucal in postcholecystectomy syndrome, determined by duodenogastric reflux (24 patients), dysfunction (21 patients) and stenosis of Oddi sphincter (17 patients) and in a control group (28 volunteers) without any complaints after cholecystectomy. A conclusion was made that dynamic hepato-biliary scintigraphy+ allowed quantitative estimation of duodenal reflux to be made and the dynamics of excretion of radiopharmagent before and after administration of cerucal may be an indicator of the functional state of the Oddi sphincter.

A method of echographic examination of duodenogastral reflux in children by means of multiple echographic studies of the gastroduodenal area is described. The presence of duodenogastral reflux is of a raw chicken egg (an acoustic marker) taken by the examinee from the acoustically shielded duodenum after it is filled with a 5% glucose solution, which is attained by a 3-time pressing of an echochamber by the pickup in the area of the projection of the duodenal bulb to the anterior abdominal wall.

Duodenogastric reflux is a naturally occurring sporadic event, the incidence, occurrence, and detrimental effects of which have been difficult to assess. The reliability of 24-hour gastric pH monitoring to detect duodenogastric reflux was studied. Central to the use of pH monitoring for this purpose is confidence in its ability to measure and display pH data in a way that reflects changes in the gastric pH environment with sufficient sensitivity. To test this the gastric pH of 10 dogs was measured in the fasting state, after feeding, and after pentagastrin stimulation. The antrum was more alkaline in the fasting state (p less than 0.01) and the display of data by frequency distribution graph was sensitive enough to reflect induced pH changes. To test the consistency of gastric pH at a given position, simultaneous 24-hour gastric monitoring was performed in 12 normal subjects with two probes placed at either 5 or 10 cm below the lower esophageal sphincter. Only at the 5-cm position did the two probes read within 1 pH unit of each other more than 90% of the time. Based on these principles, gastric pH monitoring was performed 5 cm below the lower esophageal sphincter in 30 normal subjects and 11 patients, fulfilling Ritchie's clinical criteria for pathologic duodenogastric reflux. The data obtained was arranged into 71 variables and subjected to discriminant analysis. Sixteen variables were identified, each with a corresponding coefficient to be used as a multiplier to derive a score. A score of more than +2.2 indicated a high probability of pathologic duodenogastric reflux. The test was applied to a validation population consisting of 10 additional normal subjects and 10 patients meeting Ritchie's criteria. All normal subjects had a normal score and all but one (90%) of the patients had an abnormal score. When compared to O-diisopropyl iminodiacetic acid (DISIDA) scintigraphy in another group of 22 normal subjects and 60 patients, 24-hour gastric pH monitoring was superior in the detection of pathologic duodenogastric reflux. The study shows how the application of computer technology can be used to diagnose pathologic duodenogastric reflux in patients with complex foregut complaints.

A method of ultrasound diagnosis of duodenogastric reflux was developed. It enables the reflux identification with a high accuracy. It is suggested that 3 grades of the intensity of echographically recordable duodenogastric reflux may be distinguished. The method enables an individual estimation of the action efficacy and the choice of an adequate dose of pharmacological agents, particularly metoclopramide, for the treatment of duodenogastric reflux.

Twenty patients with thoracic stomach were subjected to hepatobiliary scintigraphy for the diagnosis of duodenogastric reflux. The results of the radionuclide studies were correlated with those of endoscopy and biochemical estimation of total intragastric bile acid. Hepatobiliary scintigraphy was found to be more sensitive (91.6%) and accurate (95%) than endoscopy (25% and 55% respectively) and biochemical estimation of total intragastric bile acid content (66.6% and 80% respectively). Being noninvasive and physiological, radionuclide study appears suitable for routine clinical use in the diagnosis of duodeno-gastric reflux.

The efficacy of o-diisopropyl iminodiacetic acid (DISIDA) scanning was compared with that of computerized analysis of 24-hour gastric pH monitoring to diagnose excessive duodenogastric reflux in 22 normal volunteers and 106 consecutive patients with foregut symptoms. DISIDA scanning had a false-positive rate of 18% in the normal volunteers. Gastric pH monitoring showed an increasing prevalence of duodenogastric reflux in patients with increasing clinical evidence of this condition, which was not seen with DISIDA scanning. Both DISIDA scanning and gastric pH monitoring identified duodenogastric reflux in most patients who had had previous pyloroplasty or antrectomy. Only gastric pH monitoring, however, showed a significantly increased prevalence of duodenogastric reflux in symptomatic patients after previous cholecystectomy compared with those who had not undergone previous surgery. These data suggest that 24-hour gastric pH monitoring is superior to DISIDA scanning in identifying duodenogastric reflux as a cause of foregut symptoms.

The role of duodenogastric reflux in the pathogenesis of gastroesophageal reflux disease is not clear. Using hepatobiliary scanning techniques, we found evidence of duodenogastric reflux in six of 13 patients with Barrett's esophagus. This compares with only two positive studies in 19 control subjects. This difference is statistically significant (P = 0.038, two-tailed Fisher's exact test). Three of nine patients who had gastroesophageal reflux without Barrett's esophagus had evidence of duodenogastric reflux, a frequency not significantly different from either of the other groups. Gastroesophageal reflux of bile and pancreatic enzymes, in addition to gastric acid may contribute to the greater esophageal damage often seen in Barrett's esophagus. The presence of duodenogastric reflux in these patients may have important pathophysiologic and therapeutic implications.

The continuous 99mTc-HIDA infusion test is presented as a method for measuring duodenogastric reflux as well as for studying biliary elimination of the compound when it is administered by constant intravenous infusion. Thirty patients were studied: (a) ten patients with a T tube placed in the biliary tree were used to study the elimination of 99mTc-HIDA in the bile; (b) ten normal subjects were used as a control group; and (c) ten patients were studied who had undergone Billroth I gastrectomy for peptic ulceration. Studies of subjects in groups (b) and (c) were used to assess duodenogastric reflux by this test, correlating it with the measurement of bile acids in gastric juice. When 99mTc-HIDA was administered by constant intravenous infusion it resulted in an increased elimination in bile for the first 80-100 min, and the concentration in bile then remained relatively constant for the rest of the test. With respect to the duodenogastric reflux study group, reflux rates in the patients who had been operated on were higher than those in the control group, with statistically significant differences. Minimum reflux rates were found in the normal subjects. Assessment of reflux by 99mTc-HIDA correlated closely with the results of bile acid concentrations in Billroth I patients (r = 0.75, P less than 0.001) and control subjects (r = 0.85, P less than 0.001). Our results demonstrate that continuous 99mTc-HIDA perfusion is a useful, accurate and objective method for measuring duodenogastric reflux.

A total of 103 patients with cholelithiasis and those operated on one year ago were investigated using modified cholescintigraphy permitting the determination of a size, duration and spreading of the gastroduodenal reflux. Dynamic cholescintigraphy was shown to be an effective method of the diagnosis and quantitative estimation of the gastroduodenal reflux in patients with cholelithiasis and patients after cholecystectomy. In patients with the postcholecystectomy syndrome the gastroduodenal reflux was detected more frequently, and its quantitative indicators were lower than those in patients with cholelithiasis.

Duodenogastric reflux was studied in 48 duodenal ulcer patients before and after medical (n = 8) or surgical therapy with either combined truncal vagotomy and gastrojejunostomy (n = 13) or pyloroplasty (n = 12), Polya partial gastrectomy (n = 8), or highly selective vagotomy (n = 7). Seven healthy subjects served as controls. The reflux was assessed both by using 99mTc diethyliminodiacetic acid (HIDA) scintigraphy and by measuring intragastric bile acid levels following endoscopic gastric juice aspiration. Before therapy, duodenal ulcer patients had significantly higher intragastric bile acid concentrations than did normal subjects (p less than 0.001). After truncal vagotomy and drainage, or partial gastrectomy, bile acid levels increased significantly, whereas they remained unchanged after medical therapy. Conversely, they were found to be significantly decreased after highly selective vagotomy. The results of HIDA scan measurements were compatible with those of gastric juice bile acids. We conclude that surgical treatment for duodenal ulcer by highly selective vagotomy is the only form of therapy, among the types considered, that leads to a reduction in duodenogastric reflux. It is of interest that medical therapy of the duodenal ulcer does not improve abnormal duodenogastric reflux, possibly contributing to both the failure of the medical treatment and recurrence of the ulcer.

Cholescintigraphy with technetium 99m hydroxy imino diacetic acid (99mTc-HIDA) was used to study gallbladder emptying (GE) and duodenogastric reflux (DGR) simultaneously during the postprandial period in humans. Two groups of subjects were examined prospectively; one was a group of healthy volunteers (n = 14) and the other a group of patients with non-ulcerous dyspepsia (NUD) (n = 22). Symptoms were quantified using a clinical score (CS). GE kinetics was quantified according to two indices. DGR episodes were detected by an image-subtraction method and quantified. The group of patients with NUD showed significant early acceleration of GE (P less than 0.01). One DGR episode equivalent to 1% of the injected dose was observed in 1 of the 14 control subjects, and greater than 1% in 3 of the 22 NUD patients. However, there was no correlation between the CS, GE kinetics and DGR episodes. The physiopathological mechanism and clinical significance of these digestive motility anomalies remain to be demonstrated.

Radiologic aspiration method (99mTc-bound with EHIDA-148 MBq) was used for quantitation of duodenogastric reflux, 3 months after operations for perforated duodenal ulcers. The patients were divided in three groups of 10 each: gr. II--after simple suturing; gr. III--after truncus vagotomy and Heinecke-Mikulicz pyloroplasty and gr. IV after proximal selective vagotomy and rrhaphy. The results were compared with those in a group of practically healthy patients (gr. I). The radioactivity of the gastric aspirate was measured between the 30. and the 60. min at 15 min interval. It was found that proximal selective vagotomy with rrhaphy had minimal duodenogastric reflux and there was no difference with practically normal subjects. Truncus vagotomy was associated with significant duodenogastric reflux. Similar were the results with simple suturing.

The gastric emptying of a liquid meal (10% dextrose solution) and a semi-solid meal (minced meat, peas, potatoes and milk) was measured in the sitting position; both meals were 400 ml. Duodenogastric reflux was assessed supine after intravenous injection of 75 MBq of 99 mTc HIDA and cholecystokinin. Patients were ajudged reflux positive (R+), or reflux negative (R-) by looking at gamma camera pictures. Thirty-two duodenal ulcer patients (DU), 22 patients after truncal vagotomy and pyloroplasty (TV+P) and 21 after proximal gastric vagotomy (PGV) were studied. In DU sufferers the mean volume of early liquid emptying in R+ patients (74 ml) was similar to R- patients (78 ml). After TV+P early liquid emptying was greatly increased (mean 176 ml) but no difference was found between R+ and R- patients. After PGV excessive early emptying was less common but emptying was significantly greater in R+ patients (R+ mean = 132 ml, SD = 48 n = 8; R- mean = 63 ml, SD = 21, N = 13: t = 4.2 p less than 0.001). There was no difference in solid meal emptying between R+ and R- patients in any group.

A noninvasive scintigraphic technique was used to estimate enterogastric reflux and subsequent gastric evacuation of refluxate in 35 normal, healthy subjects and 55 patients previously treated by vagotomy or partial gastrectomy. Reflux was provoked by a milk drink and quantitated by counting 99Tcm-EHIDA activity within the gastric area during gamma camera imaging. Seven normal subjects (20%) showed reflux of 5-18% of initial activity (mean: 10%), with peak values occurring at 5-30 minutes (mean: 14 minutes) following the milk. Gastric evacuation of activity in these subjects was monoexponential (r = 0.993, T1/2 = 24.1 minutes). Reflux occurred more frequently than normal in patients with truncal vagotomy and drainage (22/28 patients) and partial gastrectomy (20/21 patients). All of 16 patients with Billroth II anastomoses exhibited reflux, which was excessive compared with refluxing normal subjects (mean: 25%; p less than 0.01) and occurred later into the study (mean: 34 minutes; p less than 0.01). Ten of 11 asymptomatic patients showed reflux of similar amounts of activity (mean: 21%) compared with 16 patients who complained of bile vomiting (mean: 22%). However, asymptomatic patients exhibited gastric evacuation of refluxate at a rate similar to that of refluxing normal subjects, while bile vomiters showed significant gastric retention of refluxate at 25-30 minutes following peak gastric activity (p less than 0.05). This result confirms that post-operative bile vomiting is essentially a problem of gastric emptying.

A prospective study of the effect of cholecystectomy on duodenogastric reflux (DGR) in dogs and humans has been performed and compared with patients presenting with persisting symptoms following cholecystectomy several years earlier. After an intravenous injection of 99mTc EHIDA, assessment of DGR was made by measuring Bilirubin Output and the percentage of 99mTc EHIDA recovered in gastric juice over fifteen minute periods. Cholecystectomy resulted in a significant increase in both amount and frequency of DGR in dogs and patients. Patients with persisting symptoms following cholecystectomy showed the greatest amount and frequency of DGR. We suggest that increased DGR may be an aetiological factor in some patients with persisting symptoms following cholecystectomy.

In this work the duodenogastric reflux was quantified as the amount of radioactivity entering the stomach after an i.v. administration of 99mTc-HIDA in ulcer patients and in patients who had undergone BI gastrectomy. The results were compared with visual evidence of gastric activity in the gamma camera images and biochemical determination of gastric bile reflux. The method is useful in quantifying the reflux if the activity is above the background activity. It allows the determination of an upper limit for the reflux when the reflux is evident visually. Only two or three images are needed for the quantitation. No correlation was found between biochemical measurement of fasting bile reflux in the stomach and radioisotopic quantification.

A prospective study is undertaken in order to demonstrate the ability of scintigraphy with a non compartmental analysis to quantitate the duodeno-gastric reflux. 24 patients have been examined, sitting in front of a gamma camera: 12 with an endoscopically proved reflux and 12 normal subjects or volunteers. About 15 min after an injection of 148 to 222 MBq 99Tcm-IDA they were given a meal labelled with 37 MBq 113Inm-DTPA. Images were recorded for 2 h. Equal size gastric and duodenal ROIs were selected over the duodenum and stomach, avoiding overlap with neighbouring organs. The reflux index based upon the occupancy principle is calculated from the gastric and duodenal curves. It is the ratio between the gastric and duodenal ROI IDA fluxes. The value of the reflux index is 3 +/- 1.8% in normal subjects and 45 +/- 33% in pathological cases. Our method, which does not require intubation, quantitatively evaluates biliary reflux independently of injected dose and hepatic or gallbladder function.

Thirty-six volunteers, asymptomatic 7 to 22 years after various operations for duodenal ulcer, were screened for enterogastric reflux by external scanning following injection of 99mTc HIDA; they also had endoscopy for measurement of the fasting juice pH, and multiple biopsies. In patients with a pH above 4 there was an association between a positive bile reflux test and the presence of pre-malignant changes in the gastric mucosa. Carcinoembryonic antigen in the gastric mucosa was found in all patients and was not, therefore, a useful screening test for stump cancer. Blind examination of two sets of endoscopic biopsies obtained 6 weeks apart in symptomatic patients with post-operative reflux gastritis showed that histological assessment remained reproducible. Gastric biopsies obtained from 16 patients before, and a year after, Roux-en-Y gastro-jejunostomy demonstrated that foveolar hyperplasia tended to regress after bile diversion.

Complete reflux of duodenal contents into the stomach with persistent retention on hepatobiliary scintigraphy or radionuclide gastrointestinal bleeding studies is a relatively rare occurrence. Two cases of complete duodenogastric reflux are reported: one case in a patient with a perforated duodenal diverticulum and the other in a patient with an inflamed, bleeding duodenal ulcer. The finding of complete duodenogastric reflux and persistent retention in the stomach should instigate a thorough evaluation for significant duodenal pathology.

Postprandial duodenogastric reflux (DGR) was assessed scintigraphically in 10 patients with postprandial dyspepsia and endoscopic evidence of bile reflux (EBR) and in two control groups comprising seven patients with similar symptoms but normal endoscopic findings and 10 asymptomatic subjects without gastrointestinal pathology. DGR of iminodiacetic acid (IDA) after a liquid Lundh meal (250 ml) was assessed dynamically with 1 minute scintiscans and DGR expressed as the percentage of IDA secreted by the liver which appeared in the gastric region. DGR varied from 0-5% in asymptomatic controls and from 0-6% in dyspeptics without EBR. DGR in patients with EBR ranged from 0-16% but only two of 10 had values outside the normal range (0-5%).

The relationship between gallbladder function and duodenogastric reflux of bile has been investigated in the fasting phase by 99Tcm-EHIDA biliary scintigraphy in 370 patients with abdominal pain. This isotope is cleared from the blood-pool by hepatocellular function and is excreted into the biliary tract. Obstruction of the common bile duct was found in 79 patients, leaving 291 who were evaluable for duodenogastric bile reflux. Gallblader function was present in 169 and absent in 122 patients. Duodenogastric reflux of bile was observed in 82 patients, 10 of whom had had previous gastric surgery. Only 298 of 169 (17%) patients with a functioning gallbladder showed evidence of enterogastric bile reflux compared to 43 of 122 (35%) with absent gallbladder function (p less than 0.005 by Chi Square). These results suggest that continuous bile flow into the duodenum in the absence of a functioning gallbladder facilitates duodenogastric reflux.

Imaging with 99mTc-IDA derivatives is a recognised technique for assessing duodenogastric reflux. A study of 150 consecutive scans has revealed a number of limitations in its use. Anatomical definition of the stomach on static imaging and computed data analysis of reflux, were often complicated by overlap by the left lobe of the liver and the duodenal-jejunal flexure. Delineation of the antrum was poor, and as it is so close to the duodenal cap and hepato-biliary activity, transient small volumes of reflux may not have been detectable. Quantification of massive reflux was easily reproducible but computer analysis of small volumes of transient reflux was often uninterpretable. A proposed clinical grading of reflux takes into account the intensity, extent and duration of reflux, and can be matched with other clinico-pathological features.

In order to evaluate if duodenogastric reflux (DGR) is associated with a different frequency of gastric dysplasia in comparison with the absence of DGR. 40 dyspeptic patients were studied. Nineteen of them had scintigraphic evidence of the DGR, while in 21 DGR was absent. The obtained results demonstrate a higher frequency of antral gastritis in presence of DGR, while fundic gastritis is similarly represented in the two studied groups. Dysplasia of the mild type is observed in 1 case of fundic atrophic gastritis without DGR and in 3 cases of atrophic gastritis with DGR (1 in fundus and 2 in antrum), thus demonstrating that reflux gastritis is not strictly correlated with dysplasia.

Enterogastric reflux was studied using the scintigraphic method in 20 patients with colonic interposition for benign esophageal disease. The state of the transplanted colonic mucosa was evaluated by endoscopy. In 16 patients, reflux of the duodenal contents into the stomach could be seen. In eight, reflux of the duodenal contents into the interposed colon could be demonstrated. There were no differences in the occurrence of reflux into the colonic graft between the isoperistaltic and antiperistaltic interpositions. In three patients, signs of colitis on the mucosa on the lower part of the graft were observed by endoscopy. Each of these patients had a reflux of the duodenal contents into the colonic graft. In monitoring the 24 hour pH of these three patients, one patient had marked acid reflux. Alkaline reflux was not observed. It is concluded that enterogastric reflux is frequent in patients with colonic interposition. Its role in the development of lower colonic graft colitis changes is discussed.

Review of hepatobiliary scintigrams in patients with serologically documented pancreatitis revealed scintigraphic abnormalities in 19 of 21 studies (90%) in 19 patients. Abnormalities included duodenal loop widening (14/21 or 65%) and duodenogastric reflux (10/21 or 48%). Total biliary obstruction was seen in five studies, thereby precluding evaluation of the gastrointestinal phase in these patients. Excluding these, duodenal loop widening and duodenogastric reflux were seen in 88% and 63% of patients respectively. We evaluated three patients in whom initial scans showed obstruction, but repeat examination showed resolution of obstruction following passage of common duct stone, with duodenal loop widening and duodenogastric reflux suggestive of acute pancreatitis. Duodenal loop widening as demonstrated by hepatobiliary scintigraphy is a sign of pancreatic enlargement in acute pancreatitis, whereas duodenogastric reflux appears to be an indirect manifestation of an adjacent inflammatory process.

New techniques in the study of gut motility must aim to improve our understanding of the flow of luminal contents, since this is the ultimate function of such motility. This paper reviews some areas of gastroduodenal motility relevant to our understanding of duodenogastric reflux. Antroduodenal motility has been studied in the past both manometrically and radiologically, but the function of the pylorus remains in doubt. Observations made using a new impedance technique at endoscopy on the timing of pyloric closure during antroduodenal motor activity suggest that the pylorus, in addition to being a functional appendage of the terminal antrum, can contract independently and in association with isolated duodenal contractions to prevent reflux. Retroperistaltic duodenal contractions, however, may not close the pylorus in time to prevent reflux, and duodenal activity rather than the pylorus may be the key to duodenogastric reflux. Studies using invasive techniques have implicated reflux in the aetiology of some gastric ulcers and gallstone dyspepsia. Non-invasive studies on reflux with the HIDA radionuclide scan have confirmed that reflux is minimal in normal subjects, more common in gallstone dyspepsia, and related to gallbladder function.

Following endoscopic gastric juice aspiration, intragastric bile acids were measured in 105 patients undergoing routine or review gastroscopy. Subsequently, duodenogastric reflux was assessed using 99mTc butyliminodiacetic acid (BIDA) scintigraphy and intragastric bile acid levels compared with the grades of reflux assessed scintigraphically. There was a significant correlation between both free and total intragastric bile acid levels and the degree of radiological bile reflux, especially when reflux was severe. Both endoscopic measurements of bile acids and BIDA scintigraphy appear to be useful methods for determining duodenogastric reflux, but neither may be accurate enough to quantify minor degrees of reflux.

A modified, quantitative cholescintigraphic method for the assessment of enterogastric reflux has been developed. The distribution of the hepatobiliary tracer 99mTc-Hida is continuously recorded by a computer for 1 h after intravenous injection of the substance. With the patient still in a supine position under the gamma camera two administrations were made orally: 1) a gelatin capsule containing a known amount of 99mTc-pertechnetate, which was studied, making possible a determination of the relation between registered counts and known activity; and 2) 99mTc-labelled Albu-Res in water, which identified the gastric region. An intravenous injection of synthetic cholecystokinin (Kinevac) 25 min after Hida administration emptied the biliary system into the duodenum in a controllable manner. The lower limit of reflux detected by this method was about 0.5% of the Hida dose given.

Duodenogastric reflux (DGR) has been assessed in healthy volunteers, patients after vagotomy and pyloroplasty, and in patients following vagotomy and pyloroplasty in addition to cholecystectomy. DGR has been assessed using bilirubin output and 99mTc EHIDA recovered in gastric juice. The control group demonstrated reflux but the quantity was small. Symptomatic patients after truncal vagotomy and pyloroplasty (V + P) showed a significant increase in DGR (P less than 0.002) when compared with the control group but the greatest reflux was seen in symptomatic patients following truncal vagotomy + pyloroplasty + cholecystectomy (P less than 0.002). AS with pyloric preservation showed no significant increase in reflux but the addition of cholecystectomy increased both frequency (P less than 0.001) and amount of reflux (P less than 0.001). We suggest that cholecystectomy when combined with a pylorus preserving or destroying procedure increases DGR and that such increased reflux may be an important factor in gastritis following peptic ulcer surgery.

We have examined the pharmacokinetics of 99mTc diethyl HIDA in five patients with a T-tube inserted into their common bile duct after choledocotomy. Blood clearance was rapid with 27.5% of the injected dose in the circulation at 2.5 min and 5% at 30 min. The peak bile excretion of 15.4% occurred between 45 and 60 min after injection of the HIDA. By 2 h 69% of the dose was excreted in the bile and 14% in the urine. In a second group of 33 patients a naso-gastric tube was passed after injection of HIDA. The patients drank 400 ml of 10% dextrose and aliquots of the stomach contents were aspirated every 10 min for an hour. In specimens with a pH greater than 4, the amount of HIDA correlated well (p less than 0.01) with the amount of bile acid determined by an enzymatic method.

Entero-gastric reflux may be assessed quantitatively using 99mTc HIDA and a gamma camera. We have devised a computer program which applies corrections for several sources of error. The technique was validated using naso-gastric aspiration and phantom experiments. In 23 patient studies, 13 patients considered not to show reflux by visual assessment had a mean percentage injected dose (PID) in the stomach of 1.9% before correction and less than 1% after correction. The 10 patients with reflux showed a fall of PID from 5.8% to 1.7% as a result of the correction. In 14 patients the mean PID in the stomach after computer correction (3%) was not significantly different from that (3.5%) measured by aspiration. Computer correction of bile reflux data is essential when attempting to quantify the amount of entero-gastric reflux using a gamma camera.

Fifty-seven patients undergoing routine or review gastroscopy had multiple gastric biopsies taken and assessed histologically for gastritis, metaplasia and dysplasia. Duodenogastric reflux was graded scintigraphically by BIDA Scanning. Patients with dysplastic changes in the gastric mucosa (n = 33) had a higher mean grade of reflux 2.1 +/- 0.21 (mean +/- SEM) than patients with no dysplasia (1.1 +/- 0.24: P less than 0.0025). Patients with metaplasia (n = 33) had an increased mean grade of reflux of 2.0 +/- 0.19 compared with patients without metaplasia (1.3 +/- 0.29: P less than 0.05), but there was no significant difference in degree of reflux between patients with and without gastritis. When the grade of reflux was plotted against increasing degrees of mucosal abnormalities, there appeared to be a positive correlation between duodenogastric reflux and severity of mucosal change.

The incidence and severity of alkaline reflux esophagitis occurring in 1129 gastroresected patients were evaluated. As far as the incidence of esophagitis are concerned, no significant difference was found after Billroth I or Billroth II type resection. Severe esophagitis developed in 62.6 per cent of patients with total gastrectomy, but never occurred when a long limb Roux-en-Y anastomosis was also performed. The majority of esophagitis was recognized within the first year after resection, so it might be supposed that not only operative procedure itself but the postoperative care period might be responsible for the development of esophagitis. It can be avoided and treated by Roux-en-Y anastomosis. Scintigraphy is a simple rapid method in the detection of gastroesophageal reflux, thus patients can be selected by it for further invasive investigation.

Duodenogastric reflux (DGR) could be implicated in several esophageal and gastric diseases. Establishing its pathophysiological role however is difficult because of the problems in the demonstration and quantification of DGR episodes. The aim of this study was to improve a scintigraphic method of detection and quantification of DGR episodes during the postprandial period in man. The study was carried out in 14 control subjects (7 males and 7 females, median age = 25 years, range: 22-35 years). As scintigraphic recording was continuous during 150 min, all DGR episodes were revealed. In order to improve visual detection of DGR episodes, images were treated by a computerized image subtraction method. The visual detection limit of DGR episodes determined by comparison to test images was 0.6 p. 100 of the dose injected intravenously or 17 microCi. A DGR episode was demonstrated in one of the 14 control subjects. The quantity of refluxed liquid was estimated, in this case, at 30 microCi, and the duration of the reflux greater than 2 min. Continuous scintigraphic recording in association with a computer based technique of image subtraction seems to improve scintigraphic performance in the study of DGR episodes under pathological conditions.