David F. Evans

Antireflux operations at flexible endoscopy using endoluminal stitching techniques: an experimental study

BACKGROUND Three antireflux operations-gastroplasty, fundoplication, and anterior gastropexy-were developed for performance at flexible endoscopy without laparotomy or laparoscopy. METHODS An endoscopic sewing machine mounted on a standard gastroscope, endoscopic knotting devices, overtube, and nylon thread were used to perform these operations in adult beagle dogs. RESULTS Gastroplasty (n = 10) was accomplished by suturing the anterior and posterior wall of the stomach to create a gastric tube (neoesophagus) along the lesser curve. An anatomic arrangement similar to fundoplication (n = 6) was achieved by invaginating the esophagus and fixing it to the stomach 2 cm distal to the cardioesophageal junction. Anterior gastropexy (n = 6) was performed using a technique similar to that used in creating percutaneous gastrostomies. There was no mortality. Ninety percent of sutures were seen at repeat endoscopy at 4 to 8 week intervals. The gastroplasty group was selected for more extensive evaluation. Manometry using a three-channel perfused catheter system before and after the procedures showed an increase in the lower esophageal sphincter pressure (preoperative median 4.6 mm Hg; post-operative median 13.33 mm Hg, p = 0.008) and cardiac yield pressures (preoperative median 10 mm Hg; postoperative median 19 mm Hg, p = 0.007). CONCLUSIONS This study demonstrates the feasibility of performing antireflux operations at flexible endoscopy, without laparoscopy or laparotomy, by use of endoluminal suturing techniques.

Correlation of the gastric emptying of nondisintegrating tablets with gastrointestinal motility

The aim of the present study was to correlate the gastric emptying (GE) of nondisintegrating tablets with changes in gastrointestinal (GI) motility. Eight, healthy, male subjects each received 5 × 7-mm radiolabeled tablets, a radiolabeled meal, and a radiotelemetry capsule (RTC). Transit of the radiolabeled formulations was followed by gamma scintigraphy and the RTC detected contractile activity in the GI tract. The study demonstrated that 7-mm tablets can empty from the fed stomach, prior to the onset of interdigestive activity. Those tablets that were not emptied during fed activity were retained through the period of quiescence associated with the onset of the migrating myoelectric complex (MMC) and left the stomach during contractions associated with phase 2 and 3 activity. The RTC was retained in the stomach and was emptied only by large phase 3 contractions commonly termed the “housekeeper” wave. However, in one subject, the RTC was retained in the stomach for over 12 hr, during which time three distinct phase 3 complexes were monitored.

Aetiology of running-related gastrointestinal dysfunction. How far is the finishing line?

Abstract30 to 65% of long distance runners experience gastrointestinal (GI) symptoms related to exercise. Several hypotheses have been postulated; however, the aetiology and pathophysiology are far from clear.The mechanical effect of running on the viscera must be involved in the development of GI symptoms in this sport. Reduction of splanchnic blood flow due to visceral vasoconstriction is another widely supported theory; nevertheless, it does not explain many of the clinical findings. Examination of the GI tract during exercise is a difficult task, and measurements of both orocaecal and whole-gut transit time have shown equivocal results. GI hormones, and especially prostaglandins, may be of crucial importance for the production of symptoms. Intestinal absorption, secretion and permeability may also be altered during exercise, provoking intestinal dysfunction. Factors such as stress, diet, dehydration, infections and other factors need to be analysed in order to present a global view of the hypotheses regarding the aetiology of this common and often overlooked problem.

The role of gastrointestinal endoscopy in long-distance runners with gastrointestinal symptoms.

Background Exercise-related gastrointestinal symptoms are not uncommon among athletes. The occurrence of gastrointestinal bleeding has been reported, especially in long-distance runners. We studied gastrointestinal mucosal damage, using gastrointestinal endoscopy, in competitive long-distance runners. Gastrointestinal blood loss and anaemia before and after running were also assessed. Methods Sixteen competitive long-distance runners (all men; age range 16–19 years) participated in the study. All runners completed a symptom questionnaire prior to a 20 km race. Stool occult blood and haematological studies (haemoglobin, haematocrit, serum iron, total iron-binding capacity [TIBC] and ferritin) were performed before and immediately after the race. Gastrointestinal endoscopy was performed to assess macroscopic changes. Colonoscopy was also performed on the patients who had positive stool occult blood before or after the race. Results Gastrointestinal symptoms were frequently experienced by the runners. Gastritis (n = 16), oesophagitis (n = 6) and gastric ulcer (n = 1) were found at gastroscopy. Colonoscopy was performed on four patients who had positive stool occult blood. One had multiple erosions at the splenic flexure and one had a rectal polyp. Five runners had anaemia, and all of these had at least one endoscopic lesion (three gastritis, two oesophagitis and one multiple erosion at the splenic flexure). There were significant changes in the following haematological parameters after the race: iron (decreased, P = 0.02), ferritin (decreased, P = 0.001) and TIBC (increased, P = 0.00005). Conclusions Gastrointestinal symptoms and gastrointestinal mucosal damage are prevalent among long-distance runners. Prior to treatment, gastrointestinal endoscopy should be considered in long-distance runners with gastrointestinal symptoms and/or anaemia.

Relationship between symptom response and oesophageal acid exposure after medical and surgical treatment for gastro-oesophageal reflux disease.

The relationship between symptom severity and objective evidence of gastro‐oesophageal reflux disease (GORD) after medical and surgical treatment has recently been questioned. This study aimed to compare the symptomatic and physiological response (as measured by pHmetry) to the treatment of GORD by proton pump inhibitors (PPIs) and by laparoscopic antireflux surgery, and to examine the relationship between the patients subjective and objective response to treatment of GORD.

Objective evaluation of small bowel and colonic transit time using pH telemetry in athletes with gastrointestinal symptoms

Background: Gastrointestinal (GI) disturbances are often reported by long distance runners and are more common in women, particularly after prolonged high intensity exercise. Objectives: To determine whether these symptoms could be associated with alterations in GI motility. Methods: Small bowel and colonic transit were measured using pH telemetry in a group of 11 female athletes (age 22 to 53 years), six of whom experienced lower GI symptoms during exercise. Subjects participated in two experimental sessions: a control measurement, where small bowel transit was estimated during a rest period (R) of six hours; and an exercise session (E), where small bowel transit was measured during a one hour period of high intensity exercise (cross country running) at >70% V˙O2max. Colonic transit was estimated indirectly from determinations of whole gut transit time by radio-opaque marker. Results: Small bowel transit time was 3.5 to 10.6 h (R) and 3.0 to 8.7 h (E) in asymptomatic athletes, versus 4.0 to 6.6 h (R) and 4.6 to 7.3 h (E) in symptomatic athletes (NS). Colonic transit time was 35.0 to 62.5 h (R) and 30.5 to 70.9 h (E) in asymptomatic athletes versus 20.4 to 42.9 h (R) and 21.5 to 67.2 h (E) in symptomatic athletes (NS). Conclusions: Small bowel and colonic transit times were similar in the two groups in the rest and exercise sessions. The diarrhoea seen in this study did not result from accelerated colonic transit. Other mechanisms must be sought.

Compliance measurement of lower esophageal sphincter and esophageal body in achalasia and gastroesophageal reflux disease.

Little is known about the effect of achalasia and gastroesophageal reflux disease (GERD) on compliance of the esophageal body and the lower esophageal sphincter (LES). Twenty-two patients with achalasia, 14 with GERD, and 14 asymptomatic volunteers were assessed. Recording apparatus consisted of a specially developed PVC bag tied to a compliance catheter, a barostat, and a polygraph. Intrabag pressures were increased incrementally while the bag volume was recorded. In each subject, pressure–volume graphs were constructed for both the esophageal body and LES and the compliance calculated. In achalasia, compliance of the esophageal body was significantly higher (P < 0.01) than in controls, whereas LES compliance was similar. Patients with GERD had a highly compliant LES in comparison to both controls and to patients with achalasia (P < 0.01 and P < 0.001, respectively); however there was no difference in their esophageal body compliance. In conclusion, foregut motility disorders can cause changes in organ compliance that are detectable using a barostat and a suitably designed compliance bag. Further measurement of compliance may provide clues to the pathogenesis of these disorders.

Human Small Bowel Motor Activity in Response to Liquid Meals of Different Caloric Value and Different Chemical Composition

Previous animal studies have shown that the nature and duration of postprandial motility in the small bowel depend both on the caloric load and the chemical composition of a meal. It is not clear whether this is also true for the human small bowel. Therefore we investigated the motor activity of the human small bowel in response to nutrient liquids of different caloric value and different chemical composition. Ten human volunteers underwent three separate, 24-hr ambulatory manometry studies. They drank water, a pure glucose solution, and Intralipid 10% in volumes of both 300 and 600 ml. The caloric value of the nutrient liquids was 330 and 660 kcal, respectively. Records were analyzed visually for the reappearance of phase III of the MMC after ingestion of a test liquid, and a validated computer program calculated the incidence and amplitude of contractions during the postprandial period. Neither duration of the postprandial interval nor the mean incidence or mean amplitude of contractions were different between the fat and the carbohydrate solutions, but phase III reappeared significantly later after ingestion of the nutrient liquids than after water (P = 0.0002). Duration of the postprandial interval also depended on the volume or the caloric load of a liquid meal (P = 0.0012). Mean incidence of contractions tended to be higher after ingestion of nutrient liquids than after water (P = 0.059). We conclude that in ambulant subjects, small bowel motor activity in response to chemically diverse liquid meals is remarkably uniform. This is true for the duration of the postprandial motor activity, as well as the incidence and amplitude of contractions during that period. The caloric value of a liquid meal, however, regulates the duration of the postprandial interval in the human small bowel.

Do pellet formulations empty from the stomach with food

Abstract The aim of the present study was to correlate the gastric emptying (GE) of a pellet formulation with changes in gastrointestinal (GI) motility. Eight, healthy, male subjects each received one capsule containing radiolabelled pellets, a radiolabelled meal and a radiotelemetry capsule (RTC). Transit of the radiolabelled formulations was followed by gamma scintigraphy. The RTC is used to detect contractile activity in the GI tract. GE of the pellet formulation did not follow any particular trend. In two of the eight subjects, the radiolabelled meal and the pellet formulation emptied from the stomach at similar rates, however, in the other six subjects the pellet formulation emptied from the stomach slower than the coadministered radiolabelled meal. The possible reasons for the delayed emptying of the pellet formulation are discussed.

Nocturnal scintigraphic imaging to investigate the gastrointestinal transit of dosage forms

Abstract Nocturnal scintigraphic imaging was used to study the effect of sleep on the gastrointestinal transit of pharmaceutical dosage forms in six healthy male volunteers. Each received five radiolabelled tablets (7 mm diameter, 4 mm thickness and weight 140 mg), a radiotelemetry capsule (8 mm diameter, 25 mm length and weight 2.08 g), and a radiolabelied test meal on two separate occasions, administered either in the morning (8.00 am) or at night (11.15 pm). The gastric residence times of the radiolabelled tablets and the radiotelemetry capsule were significantly (p