Effect of somatostatin on lower esophageal sphincter (les) pressure and serum gastrin in normal and achalasic subjects

Somatostatin analogues for acute bleeding oesophageal varices

BACKGROUND

Somatostatin and its derivatives are sometimes used for emergency treatment of bleeding oesophageal varices in patients with cirrhosis of the liver.

OBJECTIVES

To study whether somatostatin or its analogues improve survival or reduce the need for blood transfusions in patients with bleeding oesophageal varices.

SEARCH STRATEGY

PubMed and The Cochrane Library were searched (November 2007). Reference lists of publications, contacts with authors.

SELECTION CRITERIA

All randomised trials comparing somatostatin or analogues with placebo or no treatment in patients suspected of acute or recent bleeding from oesophageal varices.

DATA COLLECTION AND ANALYSIS

The outcome measures extracted were: mortality, blood transfusions, use of balloon tamponade, initial haemostasis and rebleeding. Intention-to-treat analyses including all randomised patients were conducted if possible; a random-effects analysis was preferred if there was significant heterogeneity between the trials (P < 0.10). The trials were divided in two groups: trials with a low risk of bias, which had concealed allocation of patients and were double-blind, and other trials.

MAIN RESULTS

We included 21 trials (2588 patients). The drugs did not reduce mortality significantly (relative risk 0.97, 95% confidence interval (CI) 0.75 to 1.25, for the trials with a low risk of bias, and 0.80, 95% CI 0.63 to 1.01, for the other trials). Units of blood transfused were 0.7 (0.2 to 1.1) less with drugs in the trials with a low risk of bias and 1.5 (0.9 to 2.0) less in the other trials. Number of patients failing initial haemostasis was reduced, relative risk 0.68 (0.54 to 0.87). Number of patients with rebleeding was not significantly reduced for the trials with a low risk of bias, relative risk 0.84 (0.52 to 1.37) while it was substantially reduced in the other trials, relative risk 0.36 (0.19 to 0.68). Use of balloon tamponade was rarely reported.

AUTHORS' CONCLUSIONS

The need for blood transfusions corresponded to one half unit of blood saved per patient. It is doubtful whether this effect is worthwhile. The findings do not suggest a need for further placebo-controlled trials of the type reviewed here. A large placebo controlled trial enrolling thousands of patients is needed if one wishes to rule out the possibility that a worthwhile effect on mortality might have been overlooked.

Somatostatin analogues for acute bleeding oesophageal varices

BACKGROUND

Somatostatin and its derivatives are often used for emergency treatment of bleeding oesophageal varices in patients with cirrhosis of the liver.

OBJECTIVES

To study whether somatostatin or analogues improve survival or reduce the need for blood transfusions in patients with bleeding oesophageal varices.

SEARCH STRATEGY

MEDLINE and The Cochrane Library were searched; last search in Febr 2004. Reference lists of articles, contacted authors.

SELECTION CRITERIA

All randomised trials comparing somatostatin or analogues with placebo or no treatment in patients suspected of acute or recent bleeding from oesophageal varices.

DATA COLLECTION AND ANALYSIS

The effect variables extracted were: mortality, blood transfusions, use of balloon tamponade, initial haemostasis and rebleeding. Intention-to-treat analyses including all randomised patients were conducted; a random effects analysis was preferred if there was significant heterogeneity between the trials (P < 0.10). The trials were divided in two quality groups; the better trials had concealed allocation of patients and were double-blind.

MAIN RESULTS

We included 20 trials (2518 patients). The drugs did not reduce mortality significantly (relative risk 0.96, 95% confidence interval 0.74 to 1.24, for the high-quality trials, and 0.79 for low-quality trials). Units of blood transfused were 0.7 (0.3 to 1.2) less with drugs in the high-quality trials and 1.5 (0.9 to 2.0) less in the low-quality trials. Number of patients failing initial haemostasis was reduced, relative risk 0.67 (0.53 to 0.86). Number of patients with rebleeding was not significantly reduced for the high-quality trials, relative risk 0.82 (0.45 to 1.49) while it was substantially reduced in the low-quality trials, relative risk 0.35 (0.18 to 0.67). Use of balloon tamponade was rarely reported.

AUTHORS' CONCLUSIONS

The effect corresponded to one half unit of blood saved per patient. It is doubtful whether this effect is worthwhile. The findings do not suggest a need for further placebo-controlled studies of the type reviewed here. A large placebo controlled trial enrolling thousands of patients is needed if one wishes to rule out the possibility that a worthwhile effect on mortality may have been overlooked.

Somatostatin v placebo in bleeding oesophageal varices: randomised trial and meta-analysis

OBJECTIVE

To study whether somatostatin or its derivative octreotide is more effective than placebo for treating bleeding oesophageal varices.

METHODS

Randomised, double blind trial and meta-analysis with blinded analysis of data and writing of manuscripts.

SETTING

Departments of medical and surgical gastroenterology in Copenhagen.

SUBJECTS

Patients suspected of bleeding from oesophageal varices and of having cirrhosis of the liver.

MAIN OUTCOME MEASURES

Survival, number of blood transfusions, and use of Sengstaken-Blakemore tube.

RESULTS

86 patients were randomised; in each group 16 died within six weeks (95% confidence interval for difference in mortality--19% to 22%). There were no differences between those treated with somatostatin or placebo in median number of blood transfusions (8 v 5, P = 0.07, 0 to 4 transfusions) or in numbers of patients who needed balloon tamponade (16 v 13, P = 0.54, -11% to 28%). In a meta-analysis of three trials involving 290 patients somatostatin had no effect on survival compared with placebo (P = 0.59, odds ratio 1.16; 0.67 to 2.01). For blood transfusions and use of balloon tamponade there was heterogeneity between the trials with no convincing evidence in favour of somatostatin. No placebo controlled trials have been performed with octreotide.

CONCLUSION

Within the limited power of this study and meta-analysis we were unable to show a clinical benefit of somatostatin in the emergency treatment of bleeding oesophageal varices.

Somatostatin stimulation of the normal esophagus

The inhibitory effects of somatostatin on gastric and small bowel motor function are well documented. However, the effects of somatostatin on esophageal body motility and lower esophageal sphincter tone are not completely defined. We investigated the effects of octreotide, a long-acting somatostatin analogue, on the esophageal body and the lower esophageal sphincter in 15 healthy volunteers. Lower esophageal sphincter tone was increased by octreotide infusion. Esophageal body contraction amplitude and velocity were also increased by octreotide infusion. Our data show that somatostatin stimulates the normal human esophagus, an action mediated either by a direct effect, a central nervous system action, or the inhibition of the secretion of gastrointestinal hormones that influence esophageal motor activity.

Effect of secretin on lower esophageal sphincter pressure in patients with esophageal achalasia

The effect of a bolus intravenous administration of secretin (2.0 U/kg) on resting lower esophageal sphincter pressure (LESP) was investigated in seven patients with esophageal achalasia. Basal LESP before secretin injection in the patients was 60.1 +/- 3.4 mmHg (Mean +/- SEM), which was significantly higher than 26.9 +/- 2.5 mmHg in normal controls consisting of eight healthy volunteers. LESP significantly decreased within 1 min after the injection both in the patients and the controls. The maximum pressure change from each basal LESP was 31.2 +/- 5.2 mmHg in the patients, which was significantly greater than 12.1 +/- 1.8 mmHg in the controls. The effect of secretin disappeared within 5 min in the controls. The effect in the patients, however, lasted throughout the investigation time of 30 min. It is concluded that secretin has a long-acting effect on muscular relaxation of the lower esophageal sphincter in esophageal achalsia patients.

Cholecystokinin is not a major hormonal regulator of lower esophageal sphincter pressure

Although injection of cholecystokinin can reduce resting lower esophageal sphincter pressure, the physiological significance of this finding has not been established. The purpose of this double-blind crossover study was to determine the effect of physiological plasma levels of cholecystokinin on resting lower esophageal sphincter pressure. Eighteen normal male volunteers were studied on two separate days. Following a 20-minute baseline period, subjects received infusions of saline or synthetic cholecystokinin-8 at increasing rates. Basal plasma cholecystokinin levels averaged 1.3 +/- 0.2 pmol/L (mean +/- SE) and increased to levels of 7.4 +/- 0.9 pmol/L, 12.1 +/- 2.4 pmol/L, and 23.1 +/- 3.8 pmol/L during cholecystokinin infusion rates of 21, 42, and 84 pmol/min, respectively. Lower esophageal sphincter pressure was recorded continuously with a sleeved catheter. Basal lower esophageal sphincter pressure averaged 19.9 mm Hg and did not change with the first infusion, which produced physiological peak postprandial plasma levels of cholecystokinin. Lower esophageal sphincter pressure declined only during the infusions that produced plasma cholecystokinin levels two to four times greater than normal peak postprandial levels. Since infusion of cholecystokinin to levels that reproduce physiological blood levels does not significantly decrease lower esophageal sphincter pressure, it was concluded that cholecystokinin is not a major hormonal regulator of lower esophageal sphincter relaxation.

Appearance of esophageal peristalsis in treated idiopathic achalasia

The authors studied 22 patients with severe dysphagia, and follow-up studies showed the appearance of some esophageal peristalsis for the first time in three of these patients after Heller myotomy. Comparison of pre- and postoperative clinical, radiological, and manometric data of these three subjects and the data of the other 19 patients showed no statistically significant differences between the two groups of patients either before or after cardiomyotomy except for the unusual appearance of esophageal peristalsis after surgery. According to these results it is not possible to predict which patients will develop peristalsis after cardiomyotomy. The different motor pattern observed after surgery might suggest the existence of a different pathogenesis underlying the esophageal motor disorders in these two groups of patients.