Determinants of gastro-oesophageal reflux and their inter-relationships

Respiratory physiotherapy in gastroesophageal reflux disease: A review article

Gastroesophageal reflux disease (GERD) is a frequent disorder which is expensive to diagnose and treat. Initiating therapy with empiric trial of proton-pump inhibitor is a well established strategy; however, symptoms of GERD do often persist regardless of effective medication. Nowadays, increasing interest concerning the efficacy and safety of chronic acid suppression with proton-pump inhibitors (PPIs), prompts a consideration for GERD treatment strategies related to the basic physiology of the lower esophageal sphincter, including modulation of its tone and ending of spontaneous transient lower esophageal sphincter relaxation, which contributes to reflux. Together, the lower esophageal sphincter and the crural diaphragm represent the major antireflux barrier, protecting the esophagus from reflux of gastric content. In order to prevent the need for enduring PPIs therapy or surgical procedures, substitute therapeutics approaches are being researched. Recently, studies have focused on the response of the respiratory muscles to inspiratory muscle training. As a result, inspiratory muscle training has emerged as a potential alternative for treatment of gastroesophageal reflux. The present report reviews the physiologic factors contributing to GERD, and presents the newly developed therapies that can be applied either alone or in association with available efficient GERD therapy.

Bolus retention in hiatal hernia identified by high-resolution esophageal manometry with impedance

BACKGROUND

Esophageal acid retention in a hiatal hernia (HH) may play a role in gastro-esophageal reflux. The aims of this study were to determine the prevalence of bolus retention (BR) in HH and to compare pressure profiles in patients with HH with BR in the hernia to those with bolus clearance (BC) through the hernia using high-resolution esophageal manometry with impedance (HREMI).

METHODS

Clinical HREMI studies with HH ≥1.5 cm were analyzed for lower esophageal sphincter (LES) and crural diaphragm (CD) pressures and pressure profiles during 12 saline swallows. Impedance was analyzed for swallow retention in the HH.

KEY RESULTS

Bolus retention in a HH was present in 35 of 53 (66%) patients with a HH. Patients with BR had overall lower pressure profiles including a lower basal LES pressure (14.8 ± 10.6 vs 28.9 ± 16.8 mmHg; p = 0.0001), LES-CD gradient (6.8 ± 17.9 vs 20.6 ± 12.2 mmHg; p = 0.002), residual LES pressure (2.5 ± 4.6 vs 6.1 ± 12.2 mmHg; p = 0.017), amplitude of distal esophageal contractions (83.2 ± 38.8 vs 111.2 ± 42.8 mmHg; p = 0.020), and distal contractile integral (1487 ± 1016 vs 2608 ± 1221 mmHg-cm-sec; p = 0.001) compared to the BC group. Patients with BR were more likely to have a larger sized HH compared to the BC group (3.1 ± 1.6 vs 2.1 ± 0.6 cm; p = 0.016); similar pressure changes were found when the groups were divided up by HH sizes.

CONCLUSIONS & INFERENCES

Bolus retention was seen in 66% of patients with HH. Bolus retention in the HH was associated with larger HH size, lower LES pressure, and lower esophageal contractile pressures compared to those with BC.

Respiratory physiotherapy can increase lower esophageal sphincter pressure in GERD patients

BACKGROUND

Inspiratory muscle training (IMT) has been shown to increase diaphragm thickness. We evaluated the effect of IMT on mid-respiratory pressure (MRP) in patients with gastroesophageal reflux disease (GERD) and hypotensive lower esophageal sphincter (LES), and compared the results with a sham group.

METHODS

Twenty consecutive patients (progressive loading group) and 9 controls (sham group) were included. All patients had end expiratory pressure (EEP) between 5 and 10 mmHg, underwent esophageal manometry and pulmonary function tests before and after 8 weeks of training, and used a threshold IMT twice daily. The threshold IMT was set at 30% of the maximal inspiratory pressure for the progressive loading group; while, the threshold for sham-treated patients was set at 7 cmH(2)O for the whole period.

RESULTS

There was an increase in MRP in 15 (75%) patients in the progressive loading group, with an average gain of 46.6% (p < 0.01), and in six (66%) patients in the sham group with a mean increase of 26.2% (p < 0.01). However, there was no significant difference between the groups (p = 0.507). The EEP also increased compared with measurements before training (p < 0.01), but it did not differ between groups (p = 0.727).

CONCLUSION

IMT increased LES pressure in patients with GERD, in both the treatment and sham groups, after an eight-week program. Although there was no statistically significant difference between groups, suggesting the pressure increase in LES occurs regardless of the resistance load of the threshold IMT. These findings need to be confirmed in further studies with a larger sample.

REGISTRATION NUMBER

0922/09.

Thoraco-abdominal pressure gradients during the phases of respiration contribute to gastroesophageal reflux disease

BACKGROUND AND AIMS

Exaggerated pressure fluctuation between the thorax and abdomen during exercise or with pulmonary disease may challenge the gastroesophageal barrier and allow reflux of gastric juice into the esophagus. The aim of this study was to investigate the pressure differentials in the region of the gastroesophageal junction to better understand the relationship between the thoraco-abdominal pressure gradient and the lower esophageal sphincter (LES) barrier function.

METHODS

We reviewed the esophageal motility and 24-h pH studies in 151 patients with a manometrically normal lower esophageal sphincter who did not have pulmonary disease, history of anti-reflux surgery, hiatal hernia, or ineffective esophageal motility (IEM). Intra-abdominal gastric and intra-thoracic esophageal pressure fluctuations with respiration were measured and the thoraco-abdominal pressure gradients were calculated during both inspiratory and expiratory phases of the respiratory cycle. Predictive factors for an abnormal composite pH score were identified by multivariable analysis.

RESULTS

An inspiratory thoraco-abdominal pressure gradient that was higher than the resting LES pressure was found in 27 patients. In 23 of these patients (85.2%) there was increased esophageal acid exposure (OR 13.5, 95% CI 4.4-41.8). An abnormal composite pH score was predicted by a high inspiratory thoraco-abdominal pressure gradient (P < 0.001), greater fluctuation between inspiratory and expiratory thoracic pressure (P = 0.023), lower LES resting pressure (P = 0.049) and a decreased residual pressure after a swallow induced relaxation (P = 0.002).

CONCLUSIONS

The gastroesophageal barrier function of the LES can be overcome during times when the inspiratory thoraco-abdominal pressure gradient is increased, leading to reflux of gastric juice into the esophagus. This implies that exaggerated ventilatory effort, as occurs with exercise or in respiratory disease, can result in gastroesophageal reflux.

Esophageal acid exposure in upright and recumbent postures: roles of lower esophageal sphincter, esophageal contractile and transport function, hiatal hernia, age, sex, and body mass

This study aimed to assess, using multiple regression analyses, the roles of lower esophageal sphincter, esophageal contractile and transport function, hiatal hernia, age, sex, and body mass for esophageal acid exposure in upright and recumbent postures and for esophagitis. In 116 patients with reflux symptoms, acid exposure was recorded by 24-hr pH monitoring, motility manometrically, bolus transport scintigraphically, hiatal hernia and esophagitis endoscopically. In upright posture, the percentage time at pH <4 increased significantly with higher body mass index and lower distal esophageal amplitude, the number of episodes >5 min at pH <4 with lower distal amplitude, slower transport, and higher body mass, and the longest episode at pH <4 with lower distal amplitude. In recumbency, the percentage time at pH <4 increased with lower percentage of effective esophageal contraction waves and male sex, and the number of episodes and the longest episode with lower percentage effective waves. The severity of esophagitis augmented with slower supine transport and male sex. In both postures, acid exposure and esophagitis seem to be determined primarily by impaired esophageal motility and the ensuing slow bolus transport rather than by compromised lower esophageal sphincter function and the presence and size of a hiatal hernia.

The effect of psychological stress on symptom severity and perception in patients with gastro-oesophageal reflux

OBJECTIVE

Using an experimental paradigm this investigation explored whether exposure to psychological stress would produce a significant increase in acid-reflux episodes or modify subjective perceptions of gastro-oesophageal reflux (GOR) symptoms.

METHODS

Forty-two patients presenting with heartburn and acid regurgitation underwent 24-h oesophageal pH monitoring. During the last 90 min of this monitoring period, 21 patients received a psychological stressor, while the remaining participants were randomly assigned to a no-stress control condition. State anxiety and subjective GOR symptom ratings were obtained 1 min pretest, 1 min posttest, and 40 min posttest. Cortisol samples were collected at 10-min intervals.

RESULTS

The stressor induced a significant increase in cortisol and state anxiety; however, this was not associated with any increase in reflux. Instead, the experimental group reported a dissociation between objectively measured reflux episodes and subjective symptom ratings. A similar pattern was established for participants who reported greater state anxiety, produced larger cortisol responses, or exhibited certain stress-related personality characteristics.

CONCLUSION

The perception of symptoms in the absence of increased reflux when one is stressed may account for low response rates to traditional treatments. This highlights a need to bridge the gap between psychosomatic research and clinical practice to develop more successful GOR therapies.

Nonobstructive dysphagia and recovery of motor disorder after antireflux surgery

BACKGROUND

Changes in motor disorder after Nissen 360 degrees surgery were studied based on clinical signs of preoperative nonobstructive dysphagia.

MATERIALS AND METHODS

Forty-seven patients undergoing Nissen 360 degrees fundoplication for gastroesophageal reflux were studied with pH recording and esophageal manometry before and 1 year after fundoplication. Amplitude of contraction of the distal third of the esophagus (ACDTE) and the presence of primary propulsive waves were studied.

RESULTS

Fourteen patients had clinical signs of preoperative dysphagia. Of these, 50% had an ACDTE lower than 30 mm Hg, and 71.4% nonpropulsive waves (P <0.05). Forty-three percent and 30%, respectively, of patients with dysphagia recovered ACDTE and the presence of primary propulsive waves 1 year after the procedure, as compared with 66.6% (P <0.05) and 81.8% (P <0.01%) of patients without dysphagia.

CONCLUSIONS

A correlation was found between preoperative dysphagia and esophageal motility disorders (P <0.05). One year after fundoplication, recovery was significantly higher in patients without preoperative dysphagia.

Transient lower oesophageal sphincter relaxations--a pharmacological target for gastro-oesophageal reflux disease?

The oesophago-gastric junction functions as an anti-reflux barrier preventing increased exposure of the oesophageal mucosa to gastric contents. Failure of this anti-reflux barrier results in gastro-oesophageal reflux disease, and may lead to complications such as oesophagitis, Barrett's oesophagus and eventually oesophageal carcinoma. Recent studies have suggested that transient lower oesophageal sphincter relaxation is the main mechanism underlying gastro-oesophageal reflux. It involves a prolonged relaxation of the lower oesophageal sphincter, mediated by a vago-vagal neural pathway, synapsing in the brainstem. Several drugs, such as atropine, baclofen and loxiglumide, have been shown to reduce the rate of transient lower oesophageal sphincter relaxations and concomitantly the number of reflux episodes. These findings illustrate that transient lower oesophageal sphincter relaxations may represent a potential new target for the pharmacological treatment of gastro-oesophageal reflux disease. It is possible that the reduction in the number of transient lower oesophageal sphincter relaxations may also contribute to the beneficial effect of fundoplication and new endoscopic anti-reflux procedures. It should be emphasized, however, that other factors, such as low lower oesophageal sphincter pressure, the presence of a hiatal hernia and impaired oesophageal peristalsis, are also of great importance. Therefore, whether the targeting of transient lower oesophageal sphincter relaxations is the 'golden bullet' in anti-reflux therapy remains to be proven, as evidence of an effective control of gastro-oesophageal reflux in reflux patients is still lacking.

Quality of life assessment after laparoscopic and open fundoplications. Results of a prospective, clinical study

BACKGROUND

In the evaluation of different treatment alternatives, assessment of the patients' own perceived situation can give important clinical information in addition to the conventional efficacy variables used.

METHODS

Fifty patients with chronic gastroesophageal reflux disease (GERD) were operated on with either an open fundoplication (n = 25; 17 men; mean age, 51.5 years) or with a fundoplication through the laparoscope (n = 25; 16 men; mean age, 49.8 years). In each case adequate control of the GERD was achieved with the operation, also when objectively assessed. Twelve months after surgery the quality of life was studied by using a battery of self-administered questionnaires (the Psychological General Well-being (PGWB) index and the Gastrointestinal Symptom Rating Scale (GSRS), and a visual analogue scale, depicting specific reflux-related symptoms (RVAS).

RESULTS

After antireflux surgery the overall PGWB scores were normalized with no obvious difference between the two procedures. In the GSRS scale, however, differences were shown between the two procedures, with more dyspeptic and indigestion symptoms in patients having a laparoscopic total fundic wrap.

CONCLUSION

These data emphasize the clinical efficacy of antireflux surgery, with normalization of the quality of life in terms of well-being after these procedures. It should be noted that these instruments are sensitive enough to pick up significant differences between different antireflux procedures and should therefore be frequently used in the attempt to refine and optimize long-term therapeutic alternatives in reflux disease.

Does massive obesity promote abnormal gastroesophageal reflux?

Fifty consecutive massively obese patients referred for gastroplasty operations were prospectively studied to determine the existence of gastroesophageal reflux disease by means of a standardized questionnaire, 24-hr ambulatory pH-metry, and endoscopy (27 females, mean age 48 years, range 38-57 years). These patients had a body mass index (BMI) of 42.5 +/- 5.2 kg/m2 and an actual weight of 125.5 +/- 17 kg. Heartburn and acid regurgitation was reported by 37% and 28%, respectively, mostly of a mild degree (22% and 20%). Dysphagia was reported by 2%, but none had odynophagia. No patient had any macroscopic esophagitis. The pH data were compared with those obtained in 29 age- and sex-matched, symptom-free, healthy controls (15 females, mean age 47.6 years, range 30-63 years). During ambulatory pH-metry, we recorded a predominance of daytime reflux (7.2 +/- 8.2% and total acid exposure of 5.3 +/- 6.4%) in the obese patients, but neither the weight, BMI, nor the waist-hip ratio were significantly correlated with any of the reflux variables. The pH data obtained from these patients did not, however, differ significantly from those recorded in the control population, although a somewhat lower daytime acid reflux was found in the latter group. These results suggest that massive overweight is not associated with an increased prevalence of gastroesophageal reflux disease.

Manometric assessment of the effect of the diaphragmatic crural sling in gastro-oesophageal reflux: implications for surgical management

A manometric method to measure the effect of contraction of the crural sling of the diaphragm on intraoesophageal pressure is described. The manometric crural pressure was measured in 57 patients with gastro-oesophageal reflux disease, documented by 24-h ambulatory pH monitoring, and compared between patients with and without hiatal hernia. Repeat measurements were made in 33 patients who underwent antireflux surgery that incorporated a crural repair. Mean crural pressure in 41 patients with hiatal hernia was 5.0 mmHg, compared with 15.0 mmHg in 16 without hiatal hernia (P < 0.01). In the 33 patients undergoing antireflux surgery, mean crural pressure rose from 7.1 mmHg before operation to 11.6 mmHg afterwards (P < 0.02) overall, and from 4.7 to 10.1 mmHg (P < 0.01) in the 26 patients with hiatal hernia. These results confirm a measurable contribution of the diaphragmatic crural sling to resting pressure at the high-pressure zone. The crural pressure is deficient in patients with hiatal hernia compared with that in those with reflux but no hernia. The mean crural pressure is increased in patients by antireflux surgery, particularly in those with hiatal hernia. The results provide objective support for the role of the crural diaphragm in the antireflux mechanism and the rationale of performing crural repair during antireflux surgery, particularly in the presence of hiatal hernia.

Effect of isosorbide dinitrate on gastroesophageal reflux in healthy volunteers and patients with Chagas' disease

The effect of isosorbide dinitrate (ISD) on gastroesophageal reflux and gastric emptying during the 24-min period following a liquid meal was studied in healthy volunteers, Chagas' disease patients with normal esophageal motility (CD-1 group), and Chagas' disease patients with esophageal dysmotility (CD-2 group) with dynamic scintigraphy. At random, on two separate days, the subjects received 5 mg isosorbide dinitrate or an identical-appearing placebo tablet, by the sublingual route, and ingested a liquid test meal containing [99mTc]phytate colloid before scintigraphic studies were performed. Gastroesophageal reflux episodes were more frequent (P = 0.016) and gastroesophageal reflux indexes were greater (P < 0.010) after isosorbide dinitrate than after placebo in CD-2 group (N = 15) but not in healthy volunteers (N = 14) or CD-1 group (N = 9); six of seven CD-2 patients presenting with gastroesophageal reflux after isosorbide dinitrate had abnormal clearance of refluxate. Gastric emptying was similar in healthy volunteers (N = 13), CD-1 patients (N = 6), and CD-2 patients (N = 13), and no effect of isosorbide dinitrate on it was detected in any of the groups. In separate studies, 5 mg isosorbide dinitrate reduced the lower esophageal pressure (P < 0.01) in seven CD-2 patients. These results indicate that ISD increases the tendency towards GER in CD-2 patients, but not in healthy volunteers or CD-1 patients. This effect is probably related to an exceedingly intense relaxation of the LES caused by ISD in CD-2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome 5 years after 360 degree fundoplication for gastro-oesophageal reflux disease

Forty patients with a mean age of 45 (range 22-65) years were operated on between 1982 and 1985 for gastro-oesophageal reflux disease with a short floppy 360 degree fundoplication. The results of the operation were determined by endoscopy, oesophageal manometry, ambulatory 24-h pH recording and symptom evaluation 6 months and 5 years after operation. These results were compared with findings in healthy controls. The median pressure in the lower oesophageal high-pressure zone was 13.3 (interquartile range (i.q.r.) 11.3-21.3) mmHg after 5 years, which did not differ significantly from the value at 6 months' follow-up or from that in controls. It was, however, significantly higher than the preoperative pressure. The median intra-abdominal length of the high-pressure zone was 1.7 (i.q.r. 1.3-2.3) cm after 5 years, significantly less than at 6 months but equal to control length. Measurement of the proportion of total time at pH < 4 at 5 years (median 0.2 (i.q.r. 0.0-0.6) per cent) and 6 months after operation revealed a significant reduction in acid reflux compared with preoperative values and normal controls. There was no significant difference in acid exposure between the two postoperative investigations. Endoscopy showed that 27 patients had no oesophagitis, three had erythema and three persistent Barrett's oesophagus 5 years after operation. Normal belching was possible in 22 patients and 18 experienced increased flatulence 5 years after fundoplication. An independent gastroenterologist found that the result was excellent in 16 patients, good in 16 and fair in four; two patients had a poor overall outcome of the operation. It is concluded that a 360 degree fundoplication provides good long-term control of reflux and that slight symptoms of overcompetence are common among patients operated on without affecting the overall result.

Can pH recordings suggest defective esophageal peristalsis in patients with gastroesophageal reflux?

The data provided by 24-h pH monitoring in 40 patients with gastroesophageal reflux, divided in three groups in accordance with esophageal motor pattern, were compared. Patients with hypomotility had significantly greater reflux rates than those with normal motility or hypermotility, if we consider both total time with pH < 4 and time with pH < 4 corresponding to episodes of > 5 min duration. We conclude that when 24-h pH monitoring shows very high reflux rates, basically corresponding to episodes lasting > 5 min, we should suspect the presence of defective esophageal peristalsis, which must be confirmed with a manometric study.