Development Of Gastroesophageal Reflux Research Articles

Clinical significance of hiatal hernia in the development of gastroesophageal reflux after distal gastrectomy for cancer of the stomach

The relationship between gastroesophageal reflux disease and sliding hernia is controversial, especially following distal partial gastrectomy in patients with gastric cancer. The aim of this study was to examine the relationship between gastroesophageal reflux disease and sliding hernia of the esophagus after distal gastrectomy using the gastroesophageal scintigraphy and endoscopy. Forty-five distal gastrectomy patients diagnosed with cancer of the stomach were studied. Twenty-five patients presented with reflux symptoms, such as heartburn and/or regurgitation and 20 patients exhibited no reflux symptoms. All of the patients were examined by gastroesophageal scintigraphy and their reflux indices were determined. Thirty-eight of the patients underwent upper endoscopy and both sliding hernias and reflux symptoms were classified as mild or severe. Sliding hernias were diagnosed in all of the subjects and 65.8% of the patients exhibited reflux symptoms. Evidence of endoscopic esophagitis was noted in only 39.5% of the patients. The reflux indices for the mild and severe hernia groups were 5.03 +/- 2.2 and 10.3 +/- 6.4, respectively (P < 0.05). More severely symptomatic esophagitis was prevalent in the severe hernia group in comparison to the mild group (P < 0.05). The results suggest that the onset of gastroesophageal reflux after distal gastrectomy is induced by the surgical procedures and that hiatal hernia may be an important factor in the etiology of reflux esophagitis.

Gastroesophageal reflux: a potential asthma trigger

Gastroesophageal reflux (GER) is a potential trigger of asthma. Approximately 77% of asthmatics report heartburn. GER is a risk factor for asthma-related hospitalization and oral steroid burst use. Asthmatics may be predisposed to GER development because of a high prevalence of hiatal hernia and autonomic dysregulation and an increased pressure gradient between the abdominal cavity and the thorax, over-riding the lower esophageal sphincter pressure barrier. Asthma medications may potentiate GER. Potential mechanisms of esophageal acid-induced bronchoconstriction include a vagally mediated reflex, local axonal reflexes, heightened bronchial reactivity, and microaspiration, all resulting in neurogenic inflammation. Anti-reflux therapy improves asthma symptoms in approximately 70% of asthmatics with GER. A 3-month empiric trial of twice-daily proton pump inhibitor given 30 to 60 minutes before breakfast and dinner can identify asthmatics who have GER as a trigger of their asthma.

Effects of Stamm Gastrostomy on Gastric Emptying Rate in Rats

Aim: Although frequency of gastroesophageal reflux (GER) increases after gastrostomy, the role of gastric emptying in GER has not been evaluated. In this study, we examined the effects of Stamm gastrostomy on gastric emptying rate in rats and whether Stamm gastrostomy induces GER or not. Methods: Sprague-Dawley rats were divided into three groups. Stamm gastrostomy was done in the first group (SG). Sham operation was carried out in group 2 and the 3rd group served as control. Gastric emptying was assessed using both liquid and solid meals in each group at postoperative 14th day. For solid meal emptying, after fasting of 16 h, the rats were fed for 3 h and gastric emptying rate was measured at the fifth hour. Methylcellulose was used for emptying of liquids and it was given after the animals were fasted for 16 h and gastric emptying rate was measured 30 min later. Histological evaluation for GER was performed in all groups. Results: GER was observed pathophysiologically in 5 of the 7 rats in SG group. Gastric emptying rates of liquid and solid meals were found to be similar in control, SG or sham groups. Conclusion: Surgical gastrostomy does not affect the gastric emptying of solid and liquid meals in rats. Other mechanisms should be considered in the development of GER observed following gastrostomy.

Does postoperative pH monitoring predict complicated gastroesophageal reflux in patients with esophageal atresia?

Gastroesophageal reflux (GER) is common after repair of esophageal atresia with a distal tracheoesophageal fistula (EATOF). In a retrospective study we assessed whether early 18-h pH monitoring can predict the development of EATOF-associated gastroesophageal reflux. During 1980-1997, 90 consecutive patients had primary repair for EATOF. Development of GER was classified as favorable if the patient developed no esophagitis or mild esophagitis and needed no antireflux medication, and as unfavorable if the patient developed moderate or secondary esophagitis or required an antireflux procedure. Patients who developed unfavorable GER outcome before pH monitoring or needed secondary reconstruction or those whose endoscopic follow-up data were insufficient were excluded. Eighteen-hour pH monitoring was considered pathologic if esophageal pH was <4 more than 10% of the recorded time or 5% of the recorded time minus 2 h after each meal, or if there were more than three preprandial reflux periods lasting longer than 5 min. A total of fifty patients were included into the study. pH monitoring was performed at the median age of 9.2 (range 2.5-95.0) months and classified as pathologic in 10 and normal in 40 patients. After a median follow-up of 59 (0.3-217.6) months, nine of 10 (90%) patients with pathologic pH monitoring and five of 40 (12.5%) patients with normal pH monitoring developed unfavorable outcomes ( p<.05). We conclude that early pH monitoring predicts the development of significant GER, but because 12.5% of patients with normal early pH monitoring also developed significant GER, early pH monitoring alone does not rule out the development of significant GER.

Acid reflux and asthma.

The association between asthma and gastroesophageal reflux (GER) has been further delineated with recent clinical investigations. The prevalence of GER development in asthmatics is higher than in control populations. Furthermore, asthmatics with GER have a higher risk of asthma hospitalization. Asthma medications may be one of the promoting factors for GER development in asthmatics. Inhaled albuterol decreases lower esophageal sphincter (LES) pressure and esophageal contraction amplitude. Furthermore, oral prednisone results in increased esophageal acid contact times. Respiratory symptoms also correlate with esophageal acid events. The role of neurogenic inflammation in asthma-induced bronchoconstriction is also being further developed. Therapy of GER may improve asthma outcomes in selected asthmatics. Currently, there are no double-blind, placebo-controlled, multicenter trials reporting asthma outcomes with antireflux therapy.

Gastroesophageal reflux, asthma, and mechanisms of interaction

Gastroesophageal reflux (GER) is a potential trigger of asthma. The esophagus and lung interact through a variety of mechanisms. Esophageal acid-induced bronchoconstriction can be provoked by a vagally mediated reflex, whereby acid in the distal esophagus produces airway responses; by neural enhancement of bronchial reactivity, whereby esophageal acid augments airway hyperresponsiveness; or by microaspiration, in which small amounts of esophageal acid in the upper airway cause significant airway responses. Interestingly, even in the microaspiration model, the vagus nerve plays a significant role. Neurogenic inflammation in the lung may occur with either vagally mediated mechanisms or with microaspiration. The prevalence of reflux symptoms, esophagitis, and abnormal esophageal acid contact time is higher in patients with asthma than in control populations. Potential mechanisms, whereby asthma may predispose to the development of GER, include autonomic dysregulation, an increased pressure gradient differential between the thorax and the abdomen, a high prevalence of hiatal hernia, alterations in crural diaphragm function, and bronchodilator medication use. Further research will help define how the esophagus and lung interact.

Scintigraphy in the detection of gastro-oesophageal reflux in children with caustic oesophageal burns: a comparative study with radiography and 24-h pH monitoring

Caustic injury of the oesophagus not only causes luminal narrowing but is also responsible for longitudinal contraction, resulting in gastro-oesophageal reflux (GOR), which leads to failure of conventional therapy. Therefore, the development of GOR should be investigated periodically to direct appropriate management of these patients. To determine the ability of scintigraphy to detect GOR in children with caustic oesophageal strictures in comparison with barium study and 24-h pH monitoring. Seventeen children with caustic oesophageal injury underwent scintigraphy, an upper GI barium study and 24-h pH monitoring within the same week. Five patients were also investigated post-operatively for the assessment of surgical outcome after antireflux surgery. On the whole, there was good correlation (r = 0.78, P < 0.00 l) between scintigraphy and 24-h oesophageal pH monitoring. Scintigraphy detected all but one (9/10) refluxing patients and also correctly identified all (7/7) non-refluxing patients. Barium studies demonstrated 6 out of 10 refluxing patients. There were no false-positive barium studies in non-refluxing patients. Post-operative studies demonstrated no evidence of GOR in surgically treated patients. Our results indicate that, by comparison with barium studies, scintigraphy is useful in the detection of GOR in cases with caustic oesophageal strictures and may be used as a screening modality for those under clinical follow-up.

An investigation of lower oesophageal redox potentials in gastro-oesophageal reflux patients and healthy volunteers

Oesophageal electrical properties are thought to be important in the development of gastro-oesophageal reflux. This study simultaneously monitored the intraoesophageal pH and redox potentials in 18 patients with gastro-oesophageal reflux symptoms and 15 asymptomatic controls, for a 24 h period. The pH and redox electrodes were positioned 5 cm proximal to the lower oesophageal sphincter, the position of which had been determined by manometry. Since significantly different behaviour was observed during the day and night, the data were divided into periods of waking and sleeping. Data were analysed for acid reflux and transients in the redox potential - time curve. Both patients and normal subjects showed negative redox transients which were more frequent and pronounced at night than during the day, and which were uncorrelated with acid reflux. The only parameter which was significantly different between normal and refluxing groups was the amount of nocturnal redox activity, which was lower in refluxing subjects than in normals. Some possible hypotheses for these observations, and the origin of the redox species, are discussed. Keywords: gastro-oesophageal reflux, pH monitoring, redox potential, oesophagus

Gastroesophageal Reflux after Repair of Esophageal Atresia and Tracheoesophageal Fistula.

Gastroesophageal reflux (GER) after repair of esophageal atresia and tracheoesophageal fistula (EA-TEF) is well documented. In order to clarify the effect of gastrostomy on GER after EA-TEF repair, two groups of patients, with and without gastrostomy, were compared.From 1978 to 1996, 63 consecutive patients with EA-TEF (Gross type C) underwent surgical correction without subsequent anastomotic leakage or recurrent TEF. Twenty-six patients underwent repair without gastrostomy and a routine gastrostomy was placed in 37. The two groups had similar clinical profiles and neither their mean esophageal gap between the proximal and distal esophagus nor their angle of His differed significantly. Ten patients (27.0%) with and six (23.1%) without gastrostomy developed GER and Nissen fundoplication was required in 6 of the former and 4 of the latter. There was no significant relationship between GER development and gastrostomy placement. The mean esophageal gaps in the GER and non-GER groups were 2.5 ± 0.9 and 1.2 ± 0.8cm, respectively, and they differed significantly (p<0.01). There was a significant relationship between the esophageal gap size and GER incidence (p<0.01). The mean angle of His was significantly greater in GER than non-GER patients and the angle of His correlated with the esophageal gap size.In conclusion, there appears to no relationship between GER development and gastrostomy placement, whereas there is a correlation between the esophageal gap and GER development.

Effect of level of circular myotomy on oesophageal function in a piglet model

Oesophageal continuity is often difficult to obtain in “long-gap” oesophageal atresia, and a circular myotomy may be required to achieve oesophageal anastomosis. This study compared the effects of upper and lower segmental circular myotomy on oesophageal stricture formation, oesophageal motility, and the development of gastro-oesophageal reflux (GOR) in a piglet model. Group I underwent mid-oesophageal resection with upper segment myotomy (14); group II mid-oesophageal resection with lower segment myotomy (8); and group III oesophageal transection and anastomosis without resection (6). Normal motility data were obtained from 8 unmanipulated piglets. The incidence of stricture formation was high in all operated groups. Pseudodiverticula developed in all piglets after proximal myotomy, but not after transection or distal myotomy. Lower oesophageal sphincter pressure and mean amplitude of upper oesophageal contractions were similar after operation in all groups and in controls. GOR (number of reflux episodes/24 h, number of episodes of reflux lasting more than 5 min, and fraction of time pH less than 4.0) was worse after operation compared to controls. Within each group most manometric parameters and GOR worsened with time. We found no evidence that the level of circular myotomy (upper or lower) resulted in any significant difference in stricture rate, oesophageal motility, or severity of GOR. Given the difficulty of performing an upper myotomy in long-gap atresia, where the upper segment is often very short and pseudodiverticulum formation is common, a lower-segment circular myotomy would appear to be a reasonable alternative.

Gastroesophageal reflux occurring after repair of congenital diaphragmatic hernia

Over the past 2 decades, 110 patients with congenital diaphragmatic hernia (CDH) were treated in the authors' hospital. Eighty-six survived; of these, 10 patients (11.6%) had gastroesophageal reflux (GER) after repair of CDH. Seven occurred in the past 5 years, during which time advanced intensive care including extracorporeal membrane oxygenation (ECMO) was used. Vomiting started within 4 weeks after repair of CDH in eight cases, and hiatal hernia was demonstrated in six cases. Three patients responded to conservative therapy; the other seven required antireflux surgery. Several factors are believed to be possible causes of the development of GER in CDH cases. Among them, slow pulmonary expansion of the affected side was thought to be the most important. Namely, in a case of CDH associated with severe hypoplastic lung, the esophagus may be deviated to the affected side before the lung is expanded. After expansion, the abdominal esophagus shortens, and GER or a hiatal hernia can occur in severe cases. There were seven such patients in our series of 10. With the increase in the survival rate of CDH cases associated with severe hypoplastic lung, the number of such patients also may increase. Therefore, some additional procedure to prevent the lower esophagus from sliding will be necessary in the repair of diaphragmatic hernia.

Influence of physical factors on the development of gastroesophageal reflux in man: Analysis by means of an experimental mechanical model

In this paper, the isolated influence of physical factors on the development of gastroesophageal reflux in man is analyzed by means of a mechanical model. We evaluate the influence of gravity, intraabdominal pressure, intrathoracic pressure, transmission of intraabdominal pressure to the high pressure zone, filling volume of the stomach, and the existence of a high pressure zone on the appearance of gastroesophageal reflux. PH-metry is used to record the episodes of reflux in the model. We wish to demonstrate the importance of gravity and intraabdominal pressure in the production of reflux. Intrathoracic pressure acts as an antireflux mechanism only when associated with a zone of high pressure. The intraabdominal pressure may be transmitted to the high pressure zone as a purely mechanical effect and the greater gastric filling volume may, when associated with the intraabdominal pressure, facilitate reflux without physical changes in the high pressure zone (the equivalent of a reduction in the length of the lower esophageal sphincter in man). We conclude that this model may help to explain the influence of the physical factors mentioned above on the development of gastroesophageal reflux in man.

Changes in lower esophageal sphincter pressure (LES) after stamm gastrostomy

Previous clinical and experimental reports have implicated placement of a Stamm gastrostomy (SG) as a cause of gastroesophageal reflux (GER) in children. This study evaluates this problem by measuring alterations in the lower esophageal sphincter pressure (LES) after SG with and without maintenance of the esophagogastric angle of Hiss. In 20 cats (2.8–3.2 kg) general anesthesia was induced using 20 mg/kg ketamine im. Esophageal manometrics were measured using a continuous perfusion catheter and recording system, evaluating three measurements for each animal. Eight cats (Group I) underwent SG placement in the anterior stomach wall two-thirds of the way down from the fundus. This was tacked to the anterior abdominal wall 3 cm lateral to the midline at the appropriate level. Six cats (Group II) had standard SG tube placement and in addition, two interrupted sutures were placed between the fundus and the esophagus maintaining the gastroesophageal angle of Hiss. Six cats (Group III) had sham laparotomy. After awakening, the animals were fed cat chow and water ad libitum. At 7 and 14 days, the animals were reanesthetized with ketamine and manometrics were repeated. Preoperative LES pressure measured 11.3 ± 4.7 Torr. LES pressure in Group I decreased to 6.61 ± 1.6 Torr at 7 days ( P < 0.01) and 4.8 ± 1.6 Torr at 14 days postoperatively ( P < 0.01). LES pressure in Group II was slightly decreased to 9.2 ± 3.3 Torr at 1 week ( P < 0.1) and 9.1 ± 3.5 Torr at 2 weeks ( P < 0.1) and was 9.2 ± 4.3 ( P < 0.1) and 9.2 ± 2.7 ( P < 0.1) respectively in Group III. SG caused a significant reduction in LES pressure which was prevented by maintenance of the gastroesophageal angle of Hiss. These data suggest that SG predisposes to the development of GER because of an alteration of the gastroesophageal angle.

Experimental Gastroesophageal Reflux in the Australian Brush-Tailed Possum

It has been suggested that the lower esophageal sphincter (LES) plays an important role in preventing gastroesophageal reflux. This study was designed to determine if abolition of the LES alone is sufficient to induce gastroesophageal reflux and esophagitis. Studies were performed in the Australian brush-tailed possum (Trichosurus vulpecula) which has a lower esophagus resembling that of man. Esophageal manometry, esophagoscopy, and contrast radiography of the lower esophagus and stomach were performed before and after surgery in a group of animals undergoing cardioplasty and in a group of sham operated control animals. In the animals undergoing cardioplasty, LES pressure fell from a preoperative level of 12.6 +/- 1.3 mm Hg to 0 mm Hg. This was followed by the development of gastroesophageal reflux and esophagitis. Sham operation did not alter LES pressure or result in either gastroesophageal reflux or esophagitis. In 4 of 5 animals undergoing cardioplasty, LES activity returned after 10 weeks, and this time gastroesophageal reflux ceased and esophagitis healed. It is concluded that abolition of the LES alone can induce gastroesophageal reflux and esophagitis.

Hiatal hernia with esophagitis. A simplified transabdominal surgical treatment.

One hundred-sixty patients were treated surgically with a valvuloplasty technique for gastroesophageal reflux and esophagitis. All but nine patients had a sliding hiatal hernia. In no case was the hernia repaired. The surgical approach, a reefing of the sling muscles plus vagotomy, was designed to restore competence to the antireflux mechanisms of the gastroesophageal area. Ninety-two percent of the patients remain symptom-free, while 8% are occasionally symptomatic. The high incidence of associated foregut diseases suggests an embryologic factor in the development of gastroesophageal reflux.