Effect of cisapride on secondary peristalsis in patients with gastroesophageal reflux disease

The role of delayed gastric emptying and impaired oesophageal body motility

Delayed gastric emptying in a variable proportion of patients with gastro-oesophageal reflux disease has been observed in most series, however a relationship between delayed gastric emptying and increased gastro-oesophageal reflux has not been convincingly demonstrated. Enhanced postprandial accommodation and delayed emptying of the proximal stomach have been described, but some controversy exists. Impaired primary peristalsis is often present especially in patients with oesophagitis and its prevalence increases with increasing severity of inflammatory mucosal lesions. Patients with gastro-oesophageal reflux disease often have defective triggering of secondary peristalsis independently of presence of oesophagitis. It is presently unclear if impaired oesophageal motility is a primary defect or an irreversible consequence of inflammation. Attempts at pharmacological improvement of impaired oesophageal motility have been so far disappointing. Patients with partially preserved neuromuscular structures need to be identified in order to select them for new prokinetic therapy.

The role of excessive esophageal acid exposure in patients with gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD), especially reflux esophagitis (RE), is characterized by excessive esophageal acid exposure. Transient lower esophageal sphincter (LES) relaxation is the major mechanism of acid reflux episodes in both healthy subjects (HS) and patients with GERD. In the sitting position, where acid reflux episodes often occur, there is no difference in the frequency of transient LES relaxations between these two groups; however, in patients with GERD, at 5 cm above the LES, the proportion of acid reflux episodes during transient LES relaxations is significantly greater than in the HS group. This difference is considered to be one of the causes of excessive esophageal acid exposure in patients with GERD, but its cause is still unclear. A recent study, which investigated the proportion of acid reflux episodes during transient LES relaxations at 2 and 7 cm above the LES, showed that there was no difference at 2 cm above the LES between HS and patients with RE, but at 7 cm they were significantly greater in patients with RE than in HS. Evaluation of acid reflux at 2 cm above the LES is difficult to measure, but the proximal extent of refluxate could be one of the important factors of excessive acid esophageal exposure in patients with RE. Ineffective esophageal motility, found in patients with moderate to severe RE, impairs esophageal bolus clearance of acid, therefore both the proximal extent of refluxate and the delay of esophageal bolus clearance of acid could be major causes of excessive esophageal acid exposure. Hiatus hernia also causes acid reflux, due to its association with hypotensive LES, and also impairs esophageal bolus clearance of acid.

Defective triggering of secondary peristalsis in patients with non-erosive reflux disease

BACKGROUND AND AIM

The pathophysiology of non-erosive reflux disease is poorly understood. Triggering of secondary peristalsis is impaired in patients with erosive esophagitis but data in patients with non-erosive reflux disease are lacking. The aim of this study was to evaluate the difference in esophageal motility between patients with non-erosive reflux disease and healthy subjects.

METHODS

Twenty patients with non-erosive reflux disease, with reflux symptoms occurring more than twice per week, and 20 healthy subjects of comparable age and sex underwent esophageal manometry. Primary peristalsis was tested with 10 swallows of a 5-mL water bolus. Secondary peristalsis was triggered by esophageal distention using a 20-mL air bolus, which was injected rapidly into the mid-esophagus. After 20 s, each stimulus was followed by a dry swallow to clear any residual air and then each stimulus was repeated five times.

RESULTS

Basal lower esophageal sphincter pressure, pressure wave amplitude in the upper, middle and lower esophagus, wave velocity and the rates of successful primary peristalsis were similar in non-erosive reflux disease patients and controls. The rate of triggering of secondary peristalsis in patients with non-erosive reflux disease (median 20%, interquartile range 0-40%) was significantly lower (P < 0.0001) than that in healthy subjects (90%, 70-100%). When secondary peristalsis occurred in patients with non-erosive reflux disease, however, there were no differences in the amplitude and velocity of secondary peristalsis between the groups.

CONCLUSIONS

Triggering of secondary peristalsis is defective in non-erosive reflux disease. This could lead to prolongation of the contact time between refluxed gastric acid and esophageal mucosa thereby leading to symptoms.

Relevance of mild ineffective oesophageal motility (IOM) and potential pharmacological reversibility of severe IOM in patients with gastro-oesophageal reflux disease

BACKGROUND

Several studies showed high prevalence of ineffective oesophageal motility (IOM) in gastro-oesophageal reflux disease (GERD) and suggested an important role for ineffective oesophageal motility in increased acid exposure. However, impedance-manometric studies proposed that only severe ineffective oesophageal motility might affect oesophageal clearance.

OBJECTIVES

(i) To re-assess the relevance of mild IOM in GERD and (ii) to test the reversibility of IOM.

METHODS

Oesophageal motility, clearance and acid exposure were assessed in 191 GERD patients: 99 without IOM; 58 with mild IOM (30-80% ineffective contractions) and 34 with severe IOM (>80% ineffective contractions). In 30 patients with oesophagitis, the potential reversibility of IOM was evaluated with edrophonium intravenously.

RESULTS

Patients with mild IOM had identical oesophageal clearance and acid exposure in comparison with those without IOM. Patients with severe IOM had a higher probability of prolonged supine clearance and acid exposure [odds ratio: 2.88 (1.16-7.17); 2.48 (0.99-6.17)]. This effect was independent of the presence of hiatal hernia and male sex. Severe IOM could be transiently reverted in 55% of patients.

CONCLUSIONS

Mild IOM does not affect oesophageal clearance. Only severe IOM is associated with prolonged clearance and acid exposure, particularly in supine periods. The edrophonium test might be useful to predict severe IOM response to prokinetic medications.

A rat surgical model of esophageal metaplasia and adenocarcinoma-induced by mixed reflux of gastric acid and duodenal contents

Recent clinical data have revealed that mixed reflux (MR) of gastric acid and duodenal contents frequently occurs in patients with gastroesophageal reflux disease and a progressive increase of MR occurs with increasing severity across gastroesophageal reflux disease. Herein we report a novel rat surgical model in which esophageal metaplasia and adenocarcinoma develop as complications of MR. The model was created by performing an esophagojejunostomy and a gastrojejunostomy 5 mm proximal to the esophagojejunal anastomosis in 40 rats. Severe inflammatory and proliferative changes, high prevalence of esophageal metaplasia (78%), and adenocarcinoma (50%) were observed in the lower part of the esophagus of rats 20 weeks after surgery. The resulting esophageal lesions resembled those described in humans and supported a progression from intestinal metaplasia to dysplasia and, ultimately, esophageal adenocarcinoma. Such a model may provide a useful tool in study of human reflux-induced carcinogenesis.

Relationship between acceleration of gastric emptying and oesophageal acid exposure in patients with endoscopy-negative gastro-oesophageal reflux disease

OBJECTIVE

A delay in gastric emptying has been reported in patients with gastro-oesophageal reflux disease (GORD), but its role in increasing the number of reflux episodes is still debated. The aim of this study was to assess the relationship between acceleration of gastric emptying and gastro-oesophageal reflux in patients with endoscopy-negative GORD and pathological oesophageal acid exposure.

MATERIAL AND METHODS

Twelve patients (7 M, age range 24-65 years) underwent 6-h postprandial (2.1 MJ meal) combined gastric emptying by real-time ultrasonography and intra-oesophageal pH monitoring after cisapride (20 mg b.i.d.) and placebo for 3 days, on two separate occasions at least 7 days apart in double-blind randomized order. Gastric emptying after placebo was also measured in 12 healthy volunteers (7 M, age range 25-54 years).

RESULTS

In the patients' group, the area under the emptying time curve was greater (p<0.01), and half and total emptying times prolonged (p<0.01) compared to the healthy subjects, 115 min (mean)+/-6 (SEM) versus 86+/-6 and 232 min+/-16 versus 160+/-7, respectively. Cisapride accelerated both half- and total gastric emptying (p<0.02): -22 min (mean); -10 to -34 (95% CI) and -48 min; -10 to -85, respectively, decreased both percentage of time at pH < 4 (p<0.01) and number of reflux episodes (p<0.05). However, no relationship was found between changes in gastric emptying and in the reflux variables by linear regression analysis (R2<0.005).

CONCLUSION

The emptying rate of the whole stomach is not a major determinant of gastro-oesophageal reflux.

Saliva transport to the distal esophagus

OBJECTIVE

During esophageal acid clearance, saliva should reach the most distal esophagus. The mechanisms responsible for saliva transport are not completely understood but it is assumed that normal peristalsis plays a significant role. The aim of this study was to assess the role of esophageal peristalsis and gravity in saliva transport to the distal esophagus.

MATERIAL AND METHODS

Esophageal transit and presence times of a 2-ml bolus of radiolabeled artificial saliva were assessed using concurrent scintigraphy and manometry in 10 healthy volunteers in the upright and supine positions before and after disruption of esophageal motility with sildenafil (50 mg).

RESULTS

With normal peristalsis, there was no difference in saliva transit to the distal esophagus between supine and upright positions 3.9 (1.5- >60.0) versus 3.3 s (1.3-8.3). Low amplitude contractions did not affect saliva transit but the disappearance of contractions after sildenafil was associated with prolonged saliva transit in supine position 7.4 (1.0- >60.0). Saliva presence time was significantly prolonged in both the upright and supine positions by esophageal dysmotility.

CONCLUSIONS

Saliva transport to the distal esophagus does not require complete normal peristalsis or gravity and mainly depends on an efficient pharyngeal pump. However, subjects in supine position with severe esophageal dysmotility might have both impaired volume clearance and delayed saliva transport, leading to abnormal acid clearance and esophagitis.

Comparison of efficacy of pantoprazole alone versus pantoprazole plus mosapride in therapy of gastroesophageal reflux disease: a randomized trial

The present study aimed to compare the efficacy for the therapy of GERD of pantoprazole alone with a combination of pantoprazole and mosapride. The study was a prospective, randomized trial involving 68 patients suffering heartburn and/or regurgitation at least twice a week for 6 weeks. Sixty-one patients consented to be randomized to receive either pantoprazole 40 mg b.i.d. (n = 33, group A) or pantoprazole 40 mg b.i.d. plus mosapride 5 mg t.d.s. (n = 28, group B) for 8 weeks. Twenty-four-hour esophageal pH-metry and endoscopy were conducted at recruitment and endoscopy was repeated at 8 weeks in all the patients studied. There were no differences in symptomatic responses to therapy between the groups (69.7% vs 89.2%; P = 0.11). The mean symptom score after 8 weeks was significantly lower in group B (3.78 +/- 3.62 vs 1.67 +/- 2.09; P = 0.009). Nonerosive esophagitis was present in 29 patients. In patients with nonerosive GERD there was no significant difference in symptomatic response to either regimen (17/20 in group A and 7/9 in group B responded; P = 0.63). In erosive esophagitis, symptomatic responses occurred more frequently in group B, 18/19 (94.7%), than in group A, 6/13 (46.2%; P = 0.003). However endoscopic healing of esophagitis occurred equally with either regimen (6/11, 54.5% in group A; 12/17, 70.5% in group B; P = 0.44). In nonerosive GERD, the addition of mosapride offers no benefit over pantoprazole alone. A combination of pantoprazole and mosapride is more effective than pantoprazole alone in providing symptomatic relief to patients with erosive GERD.

Does the addition of a prokinetic to proton pump inhibitor therapy help reduce duodenogastro-oesophageal reflux in patients with Barrett's oesophagus?

OBJECTIVE

The metaplastic change of Barrett's oesophagus is linked to both acid and duodenal reflux together with impaired motility. Proton pump inhibitors (PPI) reduce acid reflux, but no treatment is available that reduces duodenogastro-oesophageal reflux (DGOR). The aim of this study was to investigate whether adding a prokinetic to PPI treatment could improve oesophageal motility and subsequently reduce reflux.

METHODS

Two groups of patients with Barrett's oesophagus on PPI therapy (prokinetic, n = 12; placebo, n = 11) were investigated. At visit 1, ambulatory oesophageal manometry was performed, and peristaltic and simultaneous wave percentage and characteristics were measured. DGOR and pH measurements were also performed. After treatment with either the prokinetic cisapride or placebo, all investigations were repeated (visit 2). Analysis of covariance and Spearman's correlation coefficients of changes from visit 1 to visit 2 were used to compare data.

RESULTS

There was no significant difference between the two groups with respect to DGOR, DGOR characteristics, or the percentage of peristalsis and simultaneous waves and their characteristics. There was no correlation between DGOR and motility changes. Although no significant differences existed between acid reflux in the two groups, five patients with high supine acid reflux showed a significant reduction after treatment with cisapride.

CONCLUSIONS

Addition of cisapride to PPI treatment does not appear to improve oesophageal motility or reduce DGOR in patients with Barrett's oesophagus.

Mechanisms of gastroesophageal reflux and gastroesophageal reflux disease

Gastroesophageal reflux is a physiological phenomenon, occurring with different severity and duration in different individuals. Reflux occurs when this normal event results in the occurrence of symptoms/signs or complications. The pathophysiology of gastroesophageal reflux is complex and diverse, since it is influenced by factors that are genetic, environmental (e.g., diet smoking), anatomic, hormonal, and neurogenic. However, many mechanisms remain incompletely understood. Future research should focus on a better understanding of the physiology of the upper and lower esophageal sphincters, and of gastric motility. The afferent and efferent neural pathways and neuropharmacologic mediators of transient lower esophageal sphincter relaxations and gastric dysmotility require further study. The role of anatomic malformations such as hiatal hernia in children has been underestimated. While therapeutic possibilities are greater in number and largely improved, the outcomes of some treatments are far from satisfactory in many cases. In addition to development of new forms of treatment, research should address better use of currently available medical and surgical treatments.

The effect of cisapride on oesophageal motility and lower sphincter function in patients with gastro-oesophageal reflux disease

OBJECTIVES

To evaluate the efficiency by which the 5-HT4 agonist cisapride affects important motor functions involved in the control of gastro-oesophageal reflux.

METHOD

Thirty patients with proven gastro-oesophageal reflux disease (endoscopy and 24 h pH-metry) were included in a randomized, double-blind, placebo controlled study with a cross-over design. Cisapride, 20 mg b.i.d., during 4 weeks was compared with placebo. At baseline, as well as after 4 and 8 weeks all patients underwent symptom assessments, sleeve manometry with concomitant oesophageal pH-monitoring and an acid clearance test.

RESULTS

Despite adequate plasma levels cisapride had no significant effect on swallow induced peristaltic amplitude, duration, propagation speed, the elicitation of secondary peristalsis nor on acid clearance. Neither the basal tone of the lower oesophageal sphincter nor the number of transient lower oesophageal sphincter relaxations induced by gas distension of the stomach was affected by the administered dose of cisapride.

CONCLUSION

Although cisapride has been alleged to improve symptoms as well as the oesophagitis in patients with gastro-oesophageal reflux disease, we found the compound (20 mg b.i.d.) devoid of effects on important motor mechanisms involved in the pathogenesis of the disease.