Octreotide, a long-acting somatostatin analog, in the management of postoperative dumping syndrome. An update

Prevalence and pathophysiology of early dumping in patients after primary Roux-en-Y gastric bypass during a mixed-meal tolerance test

BACKGROUND

Early dumping is a poorly defined and incompletely understood complication after Roux-en-Y gastric (RYGB).

OBJECTIVE

We performed a mixed-meal tolerance test in patients after RYGB to address the prevalence of early dumping and to gain further insight into its pathophysiology.

SETTING

The study was conducted in a regional hospital in the northern part of the Netherlands.

METHODS

From a random sample of patients who underwent primary RYGB between 2008 and 2011, 46 patients completed the mixed-meal tolerance test. The dumping severity score for early dumping was assessed every 30 minutes. A sum score at 30 or 60 minutes of ≥5 and an incremental score of ≥3 points were defined as indicating a high suspicion of early dumping. Blood samples were collected at baseline, every 10 minutes during the first half hour, and at 60 minutes after the start.

RESULTS

The prevalence of a high suspicion of early dumping was 26%. No differences were seen for absolute hematocrit value, inactive glucagon-like peptide-1, and vasoactive intestinal peptide between patients with or without early dumping. Patients at high suspicion of early dumping had higher levels of active glucagon-like peptide-1 and peptide YY.

CONCLUSION

The prevalence of complaints at high suspicion of early dumping in a random population of patients after RYGB is 26% in response to a mixed-meal tolerance test. Postprandial increases in both glucagon-like peptide-1 and peptide YY are associated with symptoms of early dumping, suggesting gut L-cell overactivity in this syndrome.

PATHOPHYSIOLOGY, DIAGNOSIS AND TREATMENTOF DUMPING SYNDROME AND ITS RELATION TO BARIATRIC SURGERY

Introduction

The dumping syndrome is frequent in bariatric surgery. It is probably the most common syndrome following partial or complete gastrectomy. Its prevalence in partial gastrectomy can reach up to 50%, thus it can be a significant complication arising from some types of bariatric surgeries.

Objective:

Critical analysis on dumping syndrome, its pathophysiology, diagnosis and treatment.

Methods:

A literature review was performed using the key words: 'dumping syndrome', 'bariatric surgery' and 'rapid dumping syndrome'. Inclusion criteria were: books, original works, case reports and meta-analyzes, and the exclusion criterion was literature review. Concerning the publication time, articles were screened between 1960 and May 2015.

Results:

The dumping syndrome is complication arising from obesity surgeries, but also can be a result of vagus nerve damage. Diagnosis is done primarily through the use of questionnaires based on scores.

Conclusion:

The Sigstad score and Arts survey are valid means for assessing the dumping syndrome. Initial therapy consists in the adoption of dietary measures, short acting drugs administration.

Assessment of splanchnic blood flow using magnetic resonance imaging

BACKGROUND AND AIMS

The splanchnic circulation has an important function in the body under both physiological and pathophysiological conditions. Despite its importance, no reliable noninvasive procedures for estimating splanchnic circulation have been established. The aim of this study was to evaluate MRI as a tool for assessing intra-abdominal blood flows of the aorta, portal vein (VPO) and the major intestinal and hepatic vessels.

METHODS

In nine healthy volunteers, the proximal aorta (AOP) and distal abdominal aorta (AOD), superior mesenteric artery (SAM), celiac trunk (CTR), hepatic arteries (common and proper hepatic arteries, AHC and AHP, respectively), and VPO were localized on contrast-enhanced magnetic resonance angiography images. Volumetric flow was measured using a two-dimensional cine echocardiogram-gated phase contrast technique. Measurements were taken before and 30 min after continuous intravenous infusion of somatostatin (250 microg/h) and were independently evaluated by two investigators.

RESULTS

Blood flow measured by MRI in the VPO, SAM, AOP, AHP, and CTR significantly decreased after drug infusion. Flows in the AOD and AHC showed a tendency to decrease (P>0.05). Interrater agreement on flows in MRI was very good for large vessels (VPO, AOP, and AOD), with a concordance correlation coefficient of 0.94, as well as for smaller vessels such as the CTR, AHC, AHP, and SAM (concordance correlation coefficient =0.78).

CONCLUSION

Somatostatin-induced blood flow changes in the splanchnic region were reliably detected by MRI. MRI may be useful for the noninvasive assessment of blood flow changes in the splanchnic region.

Concomitant variations of gastric tone and duodenal motility in humans: results of a placebo-controlled study assessing octreotide and sumatriptan

OBJECTIVE

To describe the concomitant effects of octreotide and sumatriptan on fundic tone and duodenal phase III activity.

MATERIAL AND METHODS

A double-blind study was performed in nine volunteers, studied for 2 h after receiving 50 microg octreotide, 6 mg sumatriptan or placebo. Fundic tone variations were assessed by barostat while antroduodenal motility was studied concomitantly using manometry.

RESULTS

A rapid increase in intrabag volume was observed in all but one subject after both sumatriptan and octreotide administration, while only two subjects exhibited a volume variation after placebo, p<0.01. A significant decrease in the number of phasic contractions was observed after octreotide, while sumatriptan reduced only wave amplitudes (p<0.05). A total of 13 concomitant duodenal phase III-like activities were observed in the duodenum after octreotide, 3 after sumatriptan and 4 after placebo, all followed by spontaneous fundic relaxation with disappearance of phasic contractions, p<0.05. Spontaneous phase III activities were different from phases III-like activities after octreotide in velocity and duration (p<0.05).

CONCLUSIONS

Octreotide induced concomitant fundic relaxation, disappearance of phasic contractions and duodenal phase III-like activity. Sumatriptan relaxed the proximal stomach and reduced the amplitude of fundic phasic contractions without affecting concomitant antroduodenal phase III activity.

Dumping syndrome: pathophysiology and treatment

Anatomic and physiologic changes introduced by gastric surgery result in clinically significant dumping syndrome in approximately 10% of patients. Dumping is the effect of alteration in the motor functions of the stomach, including disturbances in the gastric reservoir and transporting function. Gastrointestinal hormones play an important role in dumping by mediating responses to surgical resection. Treatment options of dumping syndrome include diet, medications, and surgical revision. Poor nutrition status can be anticipated in patients who fail conservative therapy. Management of refractory dumping syndrome can be a challenge. This review highlights current knowledge about the mechanisms of dumping syndrome and available therapy.

Gastric motility disorders: management that optimizes nutritional status

Gastric motility disorders are relatively common, and treatment is often challenging. Various etiologies account for numerous clinical sequelae, with weight loss and severe protein-calorie malnutrition often seen in advanced stages of these disorders. In addition to gastrointestinal motor function, an appreciation of visceral sensation is essential to better understand the symptoms found in these patients, as well as possible therapeutic alternatives. This article provides an overview of gut motor and sensory function, techniques available for diagnosing motor disorders, and the principles of nutritional and medical management. Specific nutritional recommendations and a review of pharmacologic agents and novel treatment modalities are provided.

Dumping Syndrome

The dumping syndrome consists of early postprandial abdominal and vasomotor symptoms, resulting from osmotic fluid shifts and release of vasoactive neurotransmitters, and late symptoms secondary to reactive hypoglycemia. Effective relief of symptoms of dumping syndrome can be achieved with dietary modifications to minimize ingestion of simple carbohydrates and to exclude fluid intake during ingestion of the solid portion of the meal. More severely affected individuals may respond to agents such as pectin and guar, which increase the viscosity of intraluminal contents, or to drugs such as the alpha-glucosidase inhibitor acarbose, which blunts the rapid absorption of glucose, and the somatostatin analog octreotide, which alters gut transit and impairs release of vasoactive mediators into the bloodstream.

Motility disorders. Diagnosis and treatment for the pediatric patient

Motility disorders are common in children and may affect any area of the GI tract. The past decade has brought significant advances in the understanding of motility disorders in pediatrics. More sophisticated testing techniques have helped to differentiate normal from abnormal motility in children of different ages. Manometry now may be used to clarify the pathophysiologic defect underlying chest pain, dysphagia, rumination, gastroparesis, chronic intestinal pseudo-obstruction, and colonic neuromuscular disorders. Motility testing also may be used to identify the motor defect responsible for persistence of symptoms after surgery for GER or HD. New investigational techniques and prokinetic agents likely to be available in the future also were discussed.

Effect of sequential erythromycin and octreotide on antroduodenal manometry

BACKGROUND

In earlier studies, erythromycin stimulated but octreotide inhibited gastric antral contractions, as each drug induced phase 3-like episodes.

METHODS

To assess the effect of erythromycin pretreatment on octreotide-induced changes in antroduodenal motility, 16 patients were studied (mean age, 8.7 +/- 1.5 years, 8 male): 6 with severe gastroesophageal reflux, 4 with cyclic vomiting, 3 with gastroparesis, 2 with chronic intestinal pseudo-obstruction, and 1 with Crohn's disease and unexplained nausea and vomiting. After recording fasting antroduodenal motility for 3 hours, 1 mg/kg intravenous erythromycin was administered over 30 minutes. Sixty minutes after the erythromycin infusion, 0.5 microg/kg subcutaneous octreotide was administered, followed 1 hour later by a meal.

RESULTS

Phase 3 occurred spontaneously in 10 patients and after erythromycin in 12 patients. When administered after erythromycin, octreotide immediately induced phase 3s contractions in 15 patients, beginning in the antrum. In 7 children, some of the octreotide-induced phase 3s did not propagate. After the meal, antral contractions continued in all patients. The fed pattern was replaced in 14 patients by alternating phase 3 and phase 1 activities.

CONCLUSIONS

Pretreatment with erythromycin prevented octreotide-induced inhibition of antral contractions. Inhibition of antral contractions by octreotide may be mediated through either a direct or indirect suppression of motilin release, because antral contractions persist after pretreatment with the motilin receptor agonist erythromycin.

The therapeutic value of somatostatin and its analogues

In this review we discuss the physiological effects of somatostatin, which are mediated by specific receptor subtypes on different tissues. These observations have suggested new therapeutic possibilities for the use of the synthetic somatostatin analogues in the treatment of acromegaly as well as a number of other endocrine and non-endocrine disorders.

Effect of octreotide on gastrointestinal motility in children with functional gastrointestinal symptoms

BACKGROUND

The somatostatin analogue octreotide has been proposed as a possible therapeutic agent in patients with abnormal gastrointestinal motility. This study was conducted to study the effects of 0.5 microg/kg and 1.0 microg/kg subcutaneous octreotide on antroduodenal motility in children with chronic gastrointestinal disorders.

METHODS

Twenty-three children were studied, eight with intestinal pseudo-obstruction, six with nonulcer dyspepsia, six with gastroesophageal reflux disease, and three with intractable constipation. After recording fasting motility for more than 4 hours, the children were randomized to receive 0.5 microg/kg or 1 microg/kg of subcutaneous octreotide. Motility was recorded for another hour after feeding in 12 children.

RESULTS

Phase III of the motor migrating complex was present in 13 of 23 children before and in 21 after octreotide (p < 0.02). All phase III episodes after administration of octreotide except one originated in the small intestine. Phase IIIs after octreotide were longer and were propagated faster than the spontaneous phase IIIs. There were no antral contractions during fasting after octreotide. There was a significant decrease in phase II intestinal motor activity in the hour after administration of octreotide (p < 0.001). There was no difference in effect between the two doses. After feeding, antral contractions were present in all children, and intestinal phase IIIs were not abolished.

CONCLUSIONS

In children with chronic bowel disorders, subcutaneous octreotide induced phase IIIs that differed from spontaneous phase IIIs and were not inhibited by meals. Octreotide decreased antral motility during fasting and inhibited intestinal phase II. Feeding abolished the inhibitory effect of octreotide on antral motility.

Effects of octreotide, a somatostatin analogue, on gastric function evaluated by real-time ultrasonography

BACKGROUND

Somatostatin exerts inhibitory effects on physiological functions in the gastrointestinal tract. The actions differ, however, depending on the test meal, dose, and other factors.

AIMS

To determine by use of ultrasonography and scintigraphy the effect of a somatostatin analog, octreotide, on gastric emptying and antral contraction.

SUBJECTS

Twenty healthy men; mean age 23.9 years

METHODS

Subjects were studied for 7 days, once after subcutaneous injection of octreotide, 50 microg, 5 min before the ingestion of a test meal and once after subcutaneous injection of placebo. Ten subjects received a liquid meal, 10 others received a solid meal. With the liquid meal, gastric emptying was measured 15 min after its ingestion and antral contraction was measured for 15 min by ultrasonography. With the solid meal, gastric emptying was measured both by ultrasonography (n = 10) and by simultaneous scintigraphy (n = 6), with antral contraction measured by ultrasonography for 5 h after ingestion of the meal.

RESULTS AND CONCLUSIONS

Octreotide given with a liquid or solid meal inhibited gastric emptying in healthy subjects. A significant suppression of antral contraction occurred only with a solid meal.

Clinical uses of gut peptides

OBJECTIVE

The authors review clinical applications of gut-derived peptides as diagnostic and therapeutic agents.

SUMMARY BACKGROUND DATA

An increasing number of gut peptides have been evaluated for clinical use. Earlier uses as diagnostic agents have been complemented more recently by increasing application of gut peptides as therapeutic agents.

METHOD

The authors conducted a literature review.

RESULTS

Current experience with clinical use of gut peptides is described. Initial clinical applications focused on using secretomotor effects of gut peptides in diagnostic tests, many of which have now fallen into disuse. More recently, attention has been directed toward harnessing these secretomotor effects for therapeutic use in a variety of disorders, and also using the trophic effects of gut peptides to modulate gut mucosal growth in benign and malignant disease. Gut peptides have been evaluated in a variety of other clinical situations including use as adjuncts to imaging techniques, and modification of behaviors such as feeding and panic disorder.

CONCLUSIONS

Gut peptides have been used successfully in an increasing variety of clinical conditions. Further refinements in analogue and antagonist design are likely to lead to even more selective agents that may have important clinical applications. Further studies are needed to identity and evaluate these new agents.

Diagnostic value of dumping provocation in patients after gastric surgery

BACKGROUND

In patients after gastric surgery it is often difficult to discern symptoms from dumping from other postcibal complaints. Strict criteria for dumping provocation test have not been defined.

METHODS

The sensitivity and specificity of a dumping provocation using 50 g of glucose orally was assessed in 48 patients after gastric surgery, of whom 19 had a typical history of early dumping and 11 had a history of late dumping. Factors were heart rate, packed cell volume, breath hydrogen excretion, and blood glucose concentration.

RESULTS

An increase in heart rate of > or = 10 beats/min in the 1st h had a sensitivity of 100% and a specificity of 94% in detecting early dumping. An early rise in breath H2 excretion showed a sensitivity of 84% and specificity of 94%. The nadir blood glucose concentration was not a sensitive or specific indicator for late dumping.

CONCLUSIONS

Both an increase in heart rate of > or = 10 beats/min and a positive breath hydrogen excretion are sensitive indicators for early dumping. Late dumping is better recognized by the occurrence of subjective symptoms during provocation.

Efficacy of octreotide in diarrhoea due to Vibrio cholerae: a randomized, controlled trial

Although octreotide, a long-acting analogue of somatostatin, is currently used in the treatment of chronic secretory diarrhoea due to various causes, its role in the management of acute secretory diarrhoea is not well established. In the present study, therefore, the therapeutic value of octreotide in the management of cholera, a classical example of acute secretory diarrhoea, was investigated. During an outbreak of cholera, patients admitted with acute secretory diarrhoea of < or = 24 h duration and a purging rate > 100 ml/h were enrolled on the study and randomly assigned to octreotide (N = 17) and control (N = 16) groups. All 33 patients received intravenous fluid replacement and antibiotic treatment (200 mg ofloxacin twice daily for 3 days, by mouth). Each patient in the octreotide group was also given a subcutaneous injection containing 100 micrograms octreotide every 8 h for a maximum of six doses. The stool output of each patient was recorded every hour until there had been none for an hour, which was taken as the endpoint. Mean (S.D.) total stool output was lower [6.56 (3.7) v. 9.7 (6.5) litres] and the mean (S.D.) duration of diarrhoea after admission was shorter [32.9 (15.6) v. 47.8 (22.3); P < 0.05] in the octreotide group than in the control group. However, as both groups generally had similar purging rates, the higher volume of stools from the control group was simply the result of the longer period of diarrhoea in this group. Octreotide therefore only decreased the duration of diarrhoea in the cholera patients.

The effect of octreotide on human gastric compliance and sensory perception

Somatostatin or its analogue octreotide (OCT) has previously been shown to modulate gastric emptying, intestinal motor activity and visceral sensation. In the current study we sought to determine the effect of a single dose of OCT (1.25 micrograms kg-1 s.c.), which has previously been shown to have both motor and sensory effects, on proximal gastric compliance and on conscious perception of gastric distention. Gastric distention was performed in 13 healthy male volunteers, by either slow ramp distention (60 ml min-1) or by intermittent pressure steps (phasic distention; 4-20 mmHg) using an electronic distention device. Compliance curves (pressure-volume relationship), and thresholds for innocuous (fullness) and noxious sensations (discomfort, pain) were determined following vehicle or OCT injection. OCT consistently and significantly reduced the rate of the gastric accommodation reflex by 50%, resulting in a reduced compliance at distention pressures greater than 10 mmHg during phasic distention. In contrast, no effect was observed on the compliance curve obtained during ramp distention. OCT selectively increased the threshold for fullness during both ramp and phasic distention. During phasic distention, OCT decreased the volume thresholds for noxious (pain) sensations experienced at volumes greater than 300 ml, without affecting the corresponding pressure threshold. These findings suggest that at low distension volumes, OCT in the dosage used has a direct inhibitory effect on afferents mediating innocuous gastric sensations. The hyperalgesic effect observed during phasic distention may be secondary to OCT's inhibitory effect on the gastric accommodation reflex.

Influence of octreotide on the gastric emptying of solids and liquids in normal healthy subjects

BACKGROUND

The effects of octreotide on small intestinal and gall-bladder motility are well established. However, the influence of octreotide on the gastric emptying rate of both solids and liquids in normal healthy volunteers has never been studied.

METHODS

In nine healthy subjects, the gastric emptying rate of liquids and solids was studied in basal condition and 30 min after subcutaneous administration of 50 micrograms of octreotide, using the combined 14C-octanoic acid/13C-glycine breath test. To determine if the results were entirely due to alterations in gastric emptying, 14/13CO2 excretion rates of intraduodenally administered 14C-octanoic acid and 13C-glycine were measured in basal condition and after subcutaneous injection of octreotide.

RESULTS

After subcutaneous injection of octreotide, the gastric emptying rate of solids was decreased in all but one subject, while the gastric emptying rate of fluids was decreased in all subjects. Nevertheless, 14/13CO2 excretion rates in the breath after intraduodenally administered 14C-octanoic acid and 13C-glycine, were similar in basal condition and after subcutaneous injection of octreotide.

CONCLUSIONS

Subcutaneous injection of a single physiological dose of octreotide induces a marked delay in the gastric emptying of solids and liquids in young healthy volunteers. The combined 14C-octanoic acid/13C-glycine breath test is very well suited to demonstrate this effect, since the absorption and metabolism of octanoic acid and glycine remains unaltered after administration of octreotide.

Expanding uses of octreotide

This chapter reviews the therapeutic use of octreotide in a variety of pancreatic disorders, including acute pancreatitis, in the prevention of postoperative and post-ERCP pancreatitis, in the control of postoperative pancreatic fistulae, and in chronic pancreatitis for the control of pain and of pseudocysts and ascites. The review also discusses the use of octreotide in intestinal disorders of motility, gastrointestinal bleeding, intestinal fistulae and refractory diarrhoea, including the diarrhoeas of AIDS, diabetes, short gut, chemotherapy, ileostomy and gastric surgery. The use of octreotide in neuroendocrine tumours, both for therapy and diagnostic imaging, is reviewed briefly. The paucity of adequately controlled studies in many of these situations is indicated and the potential usefulness of octreotide estimated.