Demography, clinical characteristics, psychological and abuse profiles, treatment, and long-term follow-up of patients with gastroparesis

Small case series of gastric stimulation for the management of transplant-induced gastroparesis

BACKGROUND

Gastroparesis is a recognized complication following organ transplantation with incidences reported between 24 and 83%. Gastroparesis can complicate medical management in these patients leading to the inability to take medications and possibly chronic transplant rejection. Gastric electrical stimulation (GES) has been shown in both controlled and uncontrolled studies to reduce the frequency of nausea and vomiting and lead to weight gain in patients with gastroparesis refractory to standard medical treatment; however, there is little evidence to support the use of GES in transplant recipients. The goal was to evaluate the response of transplant patients with gastroparesis to GES and compare to nontransplant recipients.

MATERIALS AND METHODS

A questionnaire consisting of 11 questions was administered to investigate symptoms. Patients were asked to score these symptoms before and after surgery using a 0-5 Likert scale.

RESULTS

Thirteen consecutive patients underwent placement of the Enterra (Medtronic, Minneapolis, MN) device with a mean follow-up of 12 +/- 6.1 months. All three transplant patients (100%) reported an improvement in quality of life. Similarly, transplant patients were as likely as the diabetic or idiopathic patients to demonstrate improvements in symptoms of nausea, vomiting, and retching and prandial symptoms following Enterra therapy. In fact, transplant patients reported improvement in appetite and bloating symptoms more frequently than diabetics (P = 0.055 and P = 0.037, respectively).

CONCLUSION

Posttransplantation gastroparesis responds to therapy with Enterra GES as well as in patients with idiopathic or diabetic gastroparesis. Enterra therapy should be prospectively investigated in this population of patients.

Consensus recommendations for gastric emptying scintigraphy: a joint report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine

This consensus statement from the members of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine recommends a standardized method for measuring gastric emptying (GE) by scintigraphy. A low-fat, egg-white meal with imaging at 0, 1, 2, and 4 h after meal ingestion, as described by a published multicenter protocol, provides standardized information about normal and delayed GE. Adoption of this standardized protocol will resolve the lack of uniformity of testing, add reliability and credibility to the results, and improve the clinical utility of the GE test.

Gastroparesis-related hospitalizations in the United States: trends, characteristics, and outcomes, 1995-2004

OBJECTIVES

Gastroparesis is an increasingly recognized disorder. Its prevalence in the United States is unknown. We examined the trends, characteristics, and outcomes of gastroparesis-related hospitalizations during 1995-2004.

METHODS

The publicly available Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) comprises a nationally representative sample of 5-8 million hospitalizations per year. Gastroparesis-related hospitalizations were identified using the International Classification of Diseases (ICD-9) code 536.3 and compared with other hospitalizations. Multivariate regressions were used to compare for differences in the outcomes including length of stay, total charges, and in-hospital deaths.

RESULTS

Hospitalizations with gastroparesis as the primary diagnosis increased from 3,977 in 1995 to 10,252 in 2004 (+158%) and hospitalizations with gastroparesis as the secondary diagnosis increased from 56,726 to 134,146 (+136%). These compared to smaller changes in diabetes-related hospitalizations (+53%), all hospitalizations (+13%), and hospitalizations with gastroesophageal reflux disease (GERD), gastric ulcer, gastritis, or nonspecific nausea/vomiting as the primary diagnosis (-3% to +76%). Of the five upper gastrointestinal conditions studied as the primary diagnosis, gastroparesis had the longest length of stay (+15.4% to +66.2%, all P < 0.001) and the highest or second highest total charges (-7.2% to +60.6%, all P < 0.01) in 2004, with similar results in 1995.

CONCLUSIONS

The number of gastroparesis-related hospitalizations has been increasing in the United States, suggesting an increasing prevalence of gastroparesis. The economic impact of gastroparesis-related hospitalizations is significant and increasing.

Gastric Hypomotility Following Epicardial Vagal Denervation Ablation to Treat Atrial Fibrillation

We report a case of a 55-year-old man with vagal paroxysmal atrial fibrillation (AF) who was submitted to selective epicardial and endocardial atrial vagal denervation with the objective of treating AF. Radiofrequency pulses were applied on epicardial and endocardial surface of the left atrium close to right pulmonary veins (PVs) and also on epicardial surface close to left inferior PV. Following the procedure, patient presented with symptoms of gastroparesis, which was documented on CT scan and gastric emptying scintigraphy. Symptoms were transient and the patient recovered completely.

Two-channel gastric pacing with a novel implantable gastric pacemaker accelerates glucagon-induced delayed gastric emptying in dogs

BACKGROUND

The aim of the current study was to investigate the efficacy of 2-channel gastric electrical stimulation (GES) with a custom-made implantable pacemaker on delayed gastric emptying and gastric dysrhythmia induced by glucagon in dogs.

METHODS

Six dogs were studied in 4 randomized session (saline, glucagon, glucagon with single-channel or 2-channel GES). GES was applied via the first pair of electrodes for single-channel GES or the first and third pairs of electrodes for 2-channel GES. Gastric emptying was assessed for 90 minutes and gastric slow waves were recorded at the same time.

RESULTS

Both single-channel and 2-channel GES improved gastric dysrhythmia (P < .05 vs glucagon session). Two-channel GES but not single-channel GES improved glucagon-induced delayed gastric emptying at 30 minutes, 45 minutes, 60 minutes, 75 minutes, and 90 minutes.

CONCLUSION

Two-channel GES with a novel implantable pacemaker is more efficient and effective than single-channel GES in improving delayed gastric emptying induced by glucagon. This implantable multipoint pacemaker may provide a new option for treatment of gastric motility disorders.

Parametric study of neural gastric electrical stimulation in acute canine models

Manipulation of gastric motility by gastric electrical stimulation (GES) has been suggested as a minimally invasive alternative treatment of gastric motility disorders and obesity. However, only neural GES (NGES) has been successful in invoking gastric contractions. Nevertheless, the relationship between these contractions and the controlling NGES parameters has not been quantified. We aimed at determining the relationship between the electrical energy delivered to the tissue as a function of NGES parameters, and the strength and duration of the resulting invoked gastric contractions. Five healthy mongrel dogs underwent subserosal prepyloric implantation of two NGES electrode pairs. Gastric motility was captured by a force transducer implanted in the vicinity of the distal pair of stimulating electrodes. Custom-designed implantable stimulator delivered NGES with 8-16 V (peak-to-peak) amplitudes, and 60-100% duty cycles. Normalized motility index (MI) was utilized to quantify the contractions recorded from the force transducer. The MI increased with increasing voltage amplitudes. However, it remained remarkably constant across all duty cycles when voltage was held constant. Calculated motility generation efficiency indices (MGEI) indicated that highest energy efficiency for invoked motility was achieved at the lowest duty cycle. The parametric data obtained in the present study can be utilized to optimize the power efficiency of implantable gastric neurostimulators.

Gastric electric stimulation for the treatment of gastroparesis

Gastric electric stimulation is an emerging therapy for refractory gastroparesis. Several methods have been used to electrically stimulate the stomach. Initial studies used gastric electrical pacing, which entrains and paces the gastric slow waves at a slightly higher rate than the patient's normal myoelectric frequency of 3 cycles per minute (cpm). The technique currently practiced uses high-frequency, low-energy stimulation at four times the basal rate (12 cpm). Results from published studies with high-frequency stimulation reveal an improvement in symptoms, primarily of nausea and vomiting, and primarily in patients with diabetic gastroparesis, with only a modest change in gastric emptying. As treatment with gastric electric stimulation evolves, further delineation of its overall effectiveness, the type of patient that will likely respond, optimal electrode placement(s), and stimulus parameters should be explored.

Type 1 diabetes and gastroparesis: diagnosis and treatment

Patients with gastroparesis present with gastrointestinal symptoms and non-gastrointestinal manifestations in association with objective delays in gastric emptying. The condition complicates the course of many patients with type 1 diabetes mellitus, usually in those with longstanding poor glycemic control with other associated diabetic complications. The diagnosis is made by directed evaluation to exclude organic diseases that can mimic the clinical presentation of gastroparesis, coupled with verification of gastric retention. Current therapy relies on dietary modifications, medications to stimulate gastric evacuation, and agents to reduce vomiting. Endoscopic and surgical options are increasingly used in patients who are refractory to drug treatment.

Review article: The diagnosis and management of gastroparesis

BACKGROUND

Gastroparesis is a disorder characterized by a delay in gastric emptying of a meal in the absence of a mechanical gastric outlet obstruction.

AIM

To provide an evidence based overview on diagnosis and management of gastroparesis.

METHODS

A PubMed search was performed using search terms including gastroparesis, gastric retention, gastric emptying, accommodation, manometry, prokinetics, antiemetics, metoclopramide, domperidone, erythromycin, botulinum toxin, gastric pacing. Relevant studies were identified and original articles and reviews were collected. References in these articles were examined for relevance and included where appropriate.

RESULTS

Diagnosis of gastroparesis is based on the presence of symptoms such as nausea, vomiting and postprandial abdominal fullness and on an objectively determined delay in gastric emptying. The true prevalence of gastroparesis is unknown. Gastric emptying can be assessed by scintigraphy and stable isotope breath tests. Management of gastroparesis consists of dietary and lifestyle measures and/or pharmacological interventions (prokinetics, antiemetics, intrapyloric botulinum toxin injection) or other interventions that focus on adequate nutrient intake either through a nasoduodenal tube, percutaneous gastrostomy or jejunostomy.

CONCLUSIONS

Accurate diagnosis of gastroparesis requires an adequate protocol to measure gastric emptying. Treatment options in gastroparesis remain limited despite the disabling nature of the disorder.

Gastrointestinal electrical stimulation for treatment of gastrointestinal disorders: gastroparesis, obesity, fecal incontinence, and constipation

Electrical stimulation of the gastrointestinal (GI) tract is an attractive concept. Since these organs have their own natural pacemakers, the electrical signals they generate can be altered by externally delivering electric currents by intramuscular, serosal, or intraluminal electrodes to specific sites in the GI tract. This article reviews the advances in electrical stimulation of the GI tract by describing various methods of GI electrical stimulation and their peripheral and central effects and mechanisms; updating the status of GI electrical stimulation in the clinical settings of gastroparesis, obesity, fecal incontinence, and constipation; and predicting future directions and developments of GI electrical stimulation technology and their areas of possible clinical applications.

Gastroparesis: symptoms, evaluation, and treatment

Gastroparesis presents with gastrointestinal symptoms and nongastrointestinal manifestations in association with objective delays in gastric emptying. The condition may complicate several systemic disorders or may be idiopathic in nature. The diagnosis is made by directed evaluation to exclude organic diseases, which can mimic the clinical presentation of gastroparesis coupled with quantification of gastric emptying. Current therapies rely on dietary modifications, medications to stimulate gastric evacuation, and agents to reduce vomiting. Endoscopic and surgical options are increasingly used for cases refractory to medication treatment.

Post-infectious gastroparesis: clinical and electerogastrographic aspects

AIMS

Post-infectious gastroparesis (PIGP) is a subgroup of idiopathic gastroparesis. The aim of this study was to identify post-viral gastroparesis and to characterize clinical and electrogastrographic aspects of the disease and their usefulness as a diagnostic tool.

METHODS

Patients diagnosed with gastroparesis were defined as PIGP if they had a clear history of an acute viral illness prior to the development of their symptoms. All patients underwent evaluation of gastric emptying and electrogastrography (EGG).

RESULTS

Seven patients met the criteria for diagnosis of PIGP. Patients' age ranged from 3 months to 47 years. A specific virus was identified in two patients (one cytomegalovirus [CMV] and one Epstein-Barr virus [EBV]). EGG was pathological in six out of seven patients. In four out of seven patients, symptoms resolved spontaneously within 4 weeks to 12 months, three patients had improved but were still symptomatic at the time of the writing of this work.

CONCLUSION

We conclude that post-infectious gastroparesis is an uncommon and often over looked condition. It is self-limiting in most cases. EGG is pathological in most patients.

Post-surgical and obstructive gastroparesis

Post-surgical gastroparesis (PSG) is recognized as a consequence of vagal nerve injury following upper abdominal surgery. It has been well documented following vagotomy for peptic ulcer surgery. With the increasing role of surgical treatment in the management of GERD and morbid obesity, PSG is now being diagnosed after fundoplication and bariatric surgery. PSG has also been reported after heart and lung transplantation, possibly due to opportunistic viral infection or motor-inhibitory effects of the immunosuppressive drugs, in addition to vagal nerve injury. Initial postoperative management of PSG should be conservative as many symptoms following abdominal surgery resolve with time. This occurs possibly because the enteric nervous system is able to adapt to the loss of vagal input or vagal reinnervation occurs. Persistent symptoms are difficult to manage and require a multidisciplinary team approach. Gastric electrical stimulation has shown promise in small series.

Severe gastroparesis: new treatment alternatives

Dopamine antagonists, such as metoclopramide and domperidone, and the motilin receptor agonist erythromycin have been the cornerstones in drug treatment of severe gastroparesis for more than a decade. No new drugs have been approved for treatment of this disorder in this period. Instead, the 5-HT4 agonist cisapride has been withdrawn due to side-effects. The effectiveness of intrapyloric botulinum toxin for gastroparesis remains to be shown. In the last decade, gastric electrical stimulation (GES) with a fully implantable device has evolved as a promising treatment, with significant effects on nausea and vomiting in most patients with severe, drug-refractory diabetic gastroparesis and postsurgical gastroparesis. A proportion of patients with severe idiopathic gastroparesis and patients with idiopathic nausea and vomiting also respond. More research is needed to achieve precise selection of responders/non-responders to GES, and to study the potential benefit of GES in other patient groups suffering from severe nausea or vomiting.

Mechanisms of disease: the pathological basis of gastroparesis--a review of experimental and clinical studies

The pathogenesis of gastroparesis is complicated and poorly understood. This lack of understanding remains a major impediment to the development of effective therapies for this condition. Most of the scientific information available on the pathogenesis of gastroparesis has been derived from experimental studies of diabetes in animals. These studies suggest that the disease process can affect nerves (particularly those producing nitric oxide, but also the vagus nerve), interstitial cells of Cajal and smooth muscle. By contrast, human data are sparse, outdated and generally inadequate for the validation of data obtained from experimental models. The available data do, however, suggest that multiple cellular targets are involved. In practice, though, symptoms seldom correlate with objective measures of gastric function and there is still a lot to learn about the pathophysiology of gastroparesis. Future studies should focus on understanding the molecular pathways that lead to gastric dysfunction, in animal models and in humans, and pave the way for the development of rational therapies.

[Diagnostic and therapeutic approach to patients with gastroparesis]

Gastroparesis is a chronic alteration of gastric motility characterized by symptoms suggestive of mechanical obstruction and delayed gastric emptying in the absence of obstruction. Gastroparesis can be idiopathic or attributable to neuropathy or myopathy as in diabetes mellitus and scleroderma or can occur after vagotomy. Diagnosis is based on symptoms (nausea, vomiting, abdominal distension and early satiety), physical examination (capotement) and on complementary investigations, the procedure of choice being isotope gastric emptying tests. Treatment depends on the clinical repercussions. In most patients, gastroparesis can be controlled by prokinetic drugs, dietary measures, exclusion of drugs that alter gastric emptying, and exhaustive control of blood glucose levels. In patients with severe gastroparesis, hospital nutritional measures (intravenous and/or enteral), gastric decompression and intravenous antiemetic and prokinetic agents are required. Aggressive nutritional therapies (parenteral or enteral nasojejunal nutrition), intrapyloric injection of botulinum toxin, implantation of a gastric stimulation device, or gastrectomy should only be used in patients unresponsive to conservative treatment or if there is selective alteration of gastric motility.

The difficult patient with gastroparesis

Gastroparesis is often difficult to manage. First of all, exact criteria for making a diagnosis of gastroparesis have not been established, and merely finding delayed gastric emptying does not justify the label. Furthermore, the relationship between symptoms and gastric emptying rate is poor, and the number of therapies with proven efficacy is extremely limited. A number of technical investigations are helpful to establish the anatomy and motor function of the upper gastrointestinal tract. In most cases where gastroparesis can be presumed or established, prokinetic therapy will be tried. A number of agents are available, with variable efficacy and tolerance. Rarely, in case of debilitating refractory symptoms, experimental or invasive therapies can be tried such as injection of botulinum toxin, enteral feeding tube insertion, gastric electrical stimulation or surgery.

Gastroparesis

Gastroparesis is a symptomatic disorder of the stomach characterized by slow or delayed gastric emptying. Diabetes and idiopathic factors account for over 60% of gastroparesis cases. Symptoms associated with delayed gastric emptying include nausea, vomiting, abdominal bloating and early satiety. Delayed gastric emptying due to gastroparesis is managed by dietary adjustments, prokinetic medications, avoidance of medications that retard gastric motor activity and optimizing glycemic control in diabetic patients. Electrical stimulation and gastric pacing are an evolving treatment option for patients who do not respond to standard medical therapy. This article provides a review of gastric motility, the etiologies of gastroparesis and therapeutic approaches to this disorder.

Diabetes induces sex-dependent changes in neuronal nitric oxide synthase dimerization and function in the rat gastric antrum

Diabetic gastroparesis is a disorder that predominantly affects women. However, the biological basis of this sex bias remains completely unknown. In this study we tested the hypothesis that a component of this effect may be mediated by the nitrergic inhibitory system of the enteric nervous system. Age-matched male and female Sprague-Dawley rats were studied 8 or 12 wk after streptozotocin (55 mg/kg body wt ip)-induced sustained hyperglycemia and compared with controls. Solid gastric emptying (GE) studies were performed in all the groups. Changes in gastric antrum neuronal nitric oxide synthase (nNOS) mRNA and protein levels were analyzed by real-time PCR and Western immunoblotting, respectively. nNOS dimerization studies were performed using low-temperature SDS-PAGE. In vitro nitrergic relaxation (area under curve/mg tissue wt) was studied after the application of electric field stimulation in an organ bath. Changes in intragastric pressure (mmHg.s) in freely moving rats in the presence or absence of N(G)-nitro-l-arginine methyl ester (nitric oxide synthase inhibitor) were examined by an ambulatory telemetric method. After diabetes induction, GE is delayed in both male and female rats. However, diabetic females exhibited significant delayed GE than in diabetic males. Compared with male controls, gastric nNOS expression and nitrergic relaxation were substantially elevated in healthy female control rats, accompanied by significantly reduced intragastric pressure. The active dimeric form and dimer-to-monomer ratio of nNOSalpha were also higher in healthy females compared with male rats (P < 0.05). Diabetic females, but not males, showed significant (P < 0.05) impairment in both gastric nNOSalpha dimerization and nitrergic relaxation, accompanied by an increase in intragastric pressure. Our data provide evidence that females may have a greater dependency on the nitrergic mechanisms in health. Furthermore, diabetes seems to affect the nitrergic system to a greater extent in females than in males. Together, these changes may account for the greater vulnerability of females to diabetic gastric dysfunction.

Electrogastrography in the management of pediatric functional dyspepsia and motility disorder

PURPOSE

Electrogastrography (EGG) is a noninvasive investigation for recording gastric myoelectrical activity. We hypothesize that children with functional dyspepsia (FD) and gastrointestinal (GI) motility disorder have abnormal gastric myoelectrical activity. We aim to study the dyspepsia symptom scores and EGG of these children and compare them with those of the normal population.

METHODS

Seventeen children aged 6 to 18 years with persistent dyspepsia symptoms but with normal investigations were recruited as the FD group. Nine children with same age as the FD group with known upper GI motility disorder were recruited as the GI group. Eight normal healthy children were recruited as controls (CL). Dyspepsia symptom score (0-18) was charted, and all had EGG performed. Gastric slow wave frequency of 2 to 4 cycles per minute is defined as normogastria. Electrogastrography is regarded as abnormal when normogastria occurs in less than 70% of recorded time. Wilcoxon rank sum test and Fisher's Exact test were performed with statistical significance at P value equal to .05.

RESULTS

Mean dyspepsia symptom score was significantly different in comparing FD and GI with CL groups (FD, 6.71; GI, 5.54; CL, 0.25; P < .001). Abnormal EGG patterns occur more often in FD than in CL (FD, 58.9%; CL, 12.5%; P = .042). Abnormal EGG patterns were found in 55.6% of GI and 12.5% of CL (P = .131).

CONCLUSIONS

Electrogastrography is a useful and noninvasive armamentarium for evaluating the abnormal myoelectrical activity in children with FD and GI motility disorder.

A case report on a patient suffering from recurrent vomiting episodes, whose condition improved markedly during pregnancy and breast feeding

Background

The normal physiology of the gastrointestinal tract has been only cursorily examined. Consequently, the pathophysiology of disturbances of the gastrointestinal functions is poorly known. Recurrent vomiting is one of many functional conditions for which it is difficult to find an explanation and to treat. In the following a case is described of a patient presenting with recurrent vomiting episodes, whose condition improved spontaneously during pregnancy and breast feeding.

Case presentation

A woman with recurrent vomiting episodes over several years was examined by esophagogastroduodenoscopy. This showed a non-peristaltic ventricle. Treatment with the procinetic drug cisapride (Prepulsid^®) improved the peristalsis and reduced the symptoms. During pregnancy and breast feeding, she was free of symptoms, in spite of having discontinued her medication with cisapride (Prepulsid^®).

Conclusion

The fact that the patient improved during pregnancy and breast feeding, would seem to indicate the involvement of factors in the physiology of pregnancy and breast feeding that are of importance for gastric motility. This deserves further investigation.

Mirtazapine for severe gastroparesis unresponsive to conventional prokinetic treatment

Gastroparesis is a condition of abnormal gastric motility characterized by delayed gastric emptying without evidence of mechanical outlet obstruction. The authors describe complete remission of recurrent postprandial discomfort, nausea, and vomiting within 1 week of starting mirtazapine in a gastroparetic patient who had failed to respond, in 7 months, to conventional prokinetics (erythromycin, metoclopramide, domperidone, perphenazine, itopride, bethanechol, and/or tegaserod) and pyloric injection of botulinum toxin. This is the first report to show that mirtazapine may be an effective alternative when gastroparesis is refractory to conventional measures.

Systematic review: applications and future of gastric electrical stimulation

BACKGROUND

Over the past 20 years, gastric electrical stimulation has received increasing attention among researchers and clinicians.

AIM

To give a systematic review on the effects, mechanisms and applications of gastric electrical stimulation.

METHODS

Medline was used to identify the articles to be included in this review. Key words used for the search included gastric electrical stimulation, gastric pacing, electrical stimulation, stomach, gastrointestinal motility, central nervous system, gastroparesis, nausea and vomiting; obesity and weight loss. Combinational uses of these keywords were made to identify relevant articles. Most of the articles included in this review ranged from 1985 to 2006.

RESULTS

Based on the general search, the review was structured as follows: (i) peripheral and central effects and mechanisms of gastric electrical stimulation; (ii) clinical applications of gastric electrical stimulation for gastroparesis and obesity and (iii) future development of gastric electrical stimulation.

CONCLUSIONS

Great progress has been made during the past decades. Gastric electrical stimulation has been shown to be effective in normalizing gastric dysrhythmia, accelerating gastric emptying and improving nausea and vomiting. Implantable device has been made available for treating gastroparesis as well as obesity. However, development of a new device and controlled clinical studies are required to further prove clinical efficacy of gastric electrical stimulation.

Update on gastrointestinal scintigraphy

Nuclear medicine offers a variety of studies for evaluating motility throughout the gastrointestinal tract. Gastric emptying remains the "gold standard" for studying gastric motor function, but its application in most centers remains limited to measuring only total gastric emptying in spite of data that show assessment of both fundal and antal function is of clinical value for evaluating patients with dyspepsia. Similarly, newer methods to study small bowel and colon transit have not gained widespread use. This review summarizes the state-of-the-art of prior established and newer scintigraphic studies with an emphasis on their clinical applications.

Abnormal ghrelin and pancreatic polypeptide responses in gastroparesis

Vagal nerve dysfunction has been implicated in the pathogenesis of diabetic gastroparesis, but its role in idiopathic gastroparesis remains uncertain. The increase in pancreatic polypeptide with sham feeding is often used as a measure of vagal integrity. Ghrelin has been suggested to function as an appetite-stimulating hormone from the gut to the brain acting through vagal afferent pathways. Systemic ghrelin also rises in part due to vagal efferent pathways. Alterations in ghrelin and its effects on appetite could play a role in gastroparesis. In this study we aimed [1] to investigate the presence of vagal nerve dysfunction in patients with idiopathic and diabetic gastroparesis and [2] to determine if alterations in ghrelin concentrations occur in gastroparesis. Normal subjects and patients with diabetic, idiopathic, or postsurgical gastroparesis underwent a sham feeding protocol. Serial blood samples were obtained for plasma ghrelin and pancreatic polypeptide. Sham feeding was characterized by an increase in pancreatic polypeptide and ghrelin in normal controls and patients with idiopathic gastroparesis. The changes in pancreatic polypeptide and ghrelin levels in diabetic and postsurgical gastroparesis were significantly less than those in normal subjects. Vagal nerve dysfunction, as evidenced by an impaired pancreatic polypeptide response with sham feeding, is present in diabetic gastroparesis but not idiopathic gastroparesis. Systemic ghrelin concentrations increased with sham feeding in normal subjects and patients with idiopathic gastroparesis but not in diabetic or postsurgical gastroparesis. Vagal function and regulation of ghrelin levels are impaired in diabetic gastroparesis.

Gastric electrical stimulation has an immediate antiemetic effect in patients with gastroparesis

BACKGROUND

Electrical stimulation has been successfully employed to treat diseases involving electro-pathology in the heart, skeletal muscles, and the brain, but not in the GI tract.

AIM

This study examined the clinical feasibility and efficacy of GES in treating patients with severe gastroparesis.

METHODS

Nausea, vomiting, GEA, and liquid and solid gastric emptying were monitored in eleven patients with refractory gastroparesis at baseline and after one week of continuous electrical stimulation administered at 12 cycles/min. Eight patients were subsequently implanted with permanent stimulation devices. Follow-up studies were conducted after 1, 3, 6, and 12 mo. of stimulation.

RESULTS

After one week of stimulation, patients' quantified symptoms of nausea and vomiting decreased significantly, and liquid emptying and GEA improved. This improvement was maintained over time in the patients who continued to receive stimulation. Emptying of solids showed progressive improvement that became significant after 3 mo. The three patients who did not receive stimulation after the trial period showed significantly higher symptoms at 12 mo.

CONCLUSION

This paper demonstrates that GES at a frequency of 12 cycles/min has an immediate antiemetic effect, followed by an improvement in disordered gastric emptying.

Delayed gastric emptying: Whom to test, how to test, and what to do

Gastroparesis, or delayed gastric emptying, is a common cause of chronic nausea and vomiting as seen in a gastroenterology practice. Diabetic, postsurgical, and idiopathic causes remain the three most common forms of gastroparesis. In addition to nausea and vomiting, symptoms of gastroparesis may include early satiety, postprandial fullness, and abdominal pain. Physiologic changes that may explain symptoms in patients with gastroparesis, in addition to delayed gastric emptying, include impaired fundic accommodation, antral hypomotility, gastric dysrhythmias, pylorospasm, and perhaps visceral hypersensitivity. Diagnosis of gastroparesis is best determined using a radioisotope-labeled solid meal with scintigraphic imaging for at least 2 hours, and preferably 4 hours, postprandially. Most commonly, a 99mTc sulfur colloid-labeled egg sandwich with imaging at 0, 1, 2, and 4 hours is used. Extension of the gastric emptying test to 4 hours improves the accuracy of the test, but unfortunately, this is not commonly performed at many centers. Emptying of liquids remains normal until the late stages of gastroparesis and is less useful. The aims of treatment should be to control symptoms and maintain adequate nutrition and hydration. Patients should be advised to eat small meals and to limit their intake of fat and fiber. Additional dietary recommendations may include increasing caloric intake in the form of liquids. For diabetic patients, control of blood glucose levels is important, as symptom exacerbation is frequently associated with poor glycemic control. Specific treatment often begins with metoclopramide, 10 mg, up to four times daily, after a discussion of possible side effects with the patient. An antiemetic agent, such as prochlorperazine, 5 to 10 mg orally or 25 mg by suppository, can be added on an as-needed basis every 4 to 6 hours to control nausea. If these antiemetic medications are not effective, or if side effects develop, orally dissolving ondansetron, 8 mg every 8 to 12 hours, can be tried on an as-needed basis. If this regimen is unsuccessful, then alternative prokinetic agents--erythromycin, 125 mg, or tegaserod, 6 mg, prior to meals--can be tried. For cases refractory to these treatments, referral to a center with US Food and Drug Administration permission to use domperidone should be considered. Alternatively, symptom modulators such as low-dose tricyclic antidepressants can be tried to reduce symptoms, but these do not improve gastric emptying. In patients for whom all medical therapy fails, other options that are tried at experienced centers include the injection of botulinum toxin into the pylorus, placement of a feeding jejunostomy, and/or placement of a gastric electrical stimulator.

Efficacy and efficiency of gastric electrical stimulation with short pulses in the treatment of vasopressin-induced emetic responses in dogs

The aim of this study was to determine the most effective and efficient anti-emetic parameters of short-pulse gastric electrical stimulation (GES) in dogs. Seven female beagle dogs implanted with four pairs of gastric electrodes were studied in eight randomized sessions (saline, vasopressin, and six GES sessions with different parameters). Each session consisted of four 20-min recordings of gastric slow waves and symptoms. In sessions 1 and 2, saline and vasopressin, respectively, were infused during the second 20-min period. The protocol of the other six sessions was the same as session 2 except that GES was continuously applied. It was found that: (1) vasopressin induced gastric dysrhythmia and emetic response (P < 0.01, anova); (2) short-pulse GES with a frequency of 14 or 40 Hz and pulse width of 0.1 or 0.3 ms, but not 0.6 ms was able to reduce symptoms induced by vasopressin; (3) short-pulse GES with a pulse width of 0.3 ms was the most effective in preventing vasopressin-induced symptoms; (4) none of the tested GES methods improved vasopressin-induced gastric dysrhythmia. We conclude that vasopressin induces gastric dysrhythmia and symptoms. Short-pulse GES with a pulse width of 0.3 ms and frequency of 14 Hz is most effective and efficient in preventing vasopressin-induced emetic responses in dogs.

Gastroparesis: clinical update

Gastroparesis refers to chronically abnormal gastric motility characterized by symptoms suggestive of mechanical obstruction and delayed gastric emptying in the absence of mechanical obstruction. It may be idiopathic or attributable to neuropathic or myopathic abnormalities, such as diabetes mellitus, postvagotomy, postviral infection, and scleroderma. Dietary and behavioral modification, prokinetic drugs, and surgical interventions have been used in managing patients with gastroparesis. Although mild gastroparesis is usually well managed with these treatment options, severe gastroparesis may be very difficult to control and may require referral to a specialist center if symptoms are intractable despite pharmacological therapy and dietetic support. New advances in drug therapy, botulinum toxin injection, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. This article critically reviews the advances in the field from the perspective of the clinician.

Treatment of gastroparesis: a multidisciplinary clinical review

This clinical review on the treatment of patients with gastroparesis is a consensus document developed by the American Motility Society Task Force on Gastroparesis. It is a multidisciplinary effort with input from gastroenterologists and other specialists who are involved in the care of patients with gastroparesis. To provide practical guidelines for treatment, this document covers results of published research studies in the literature and areas developed by consensus agreement where clinical research trials remain lacking in the field of gastroparesis.

Gastric electrical stimulation in gastroparesis: where do we stand?

Gastroparesis is a chronic disabling condition of impaired gastric motility that results in decreased quality of life. Currently available medical therapy consists of prokinetic and/or antiemetic therapy, dietary modifications, and nutritional supplementation. For patients with medication-resistant gastroparesis a non-pharmacological therapy, gastric electric stimulation, has evolved over the last decade. Based on the frequency of the electrical stimulus, gastric electric stimulation can be classified into low- and high-frequency gastric electric stimulation. The first method aims to normalize gastric dysrhythmia and entrain gastric slow waves and accelerates gastric emptying, whereas high-frequency gastric electric stimulation is unable to restore normal gastric emptying, but nevertheless stunningly reduces symptoms, such as nausea and vomiting, re-establishes quality of life, nutritional state in all patients, and metabolic control in patients with diabetic gastroparesis. Gastric electric stimulation presents a new possibility in the treatment of gastroparesis.

Nutrition and motility disorders

The purpose of this article is to give an overview of the relation between feeding and gastrointestinal symptoms and complaints, and to review different motility disorders that have implications for food intake. We also report the consequences for nutrition state and the evidence-based principles of dietary modification in patients with motility disorders.

Irritable bowel syndrome and inflammatory bowel disease: interrelated diseases?

In the past inflammatory bowel disease (IBD), celiac disease and irritable bowel syndrome (IBS) were regarded as completely separate disorders. Now, with the description of inflammation, albeit low-grade, in IBS, and of symptom overlap between IBS and celiac disease, this contention has come under question. Is there true overlap between these disorders? Despite the limitations of available data one cannot but be struck by some areas of apparent convergence: IBD and celiac disease in remission, lymphocytic colitis and microscopic inflammation in IBS, in general, and, especially, in the post-infectious IBS category. The convergence between latent celiac disease and sub-clinical IBD, on the one hand, and IBS, on the other, appears, based on available evidence, to be somewhat spurious and may largely relate to misdiagnosis, a phenomenon which may also explain the apparent evolution of IBS into IBD in some studies. Similarities between IBS and lymphocytic colitis are more striking and less readily dismissed; as for IBS, well documented instances of progression of lymphocytic colitis to full-blown IBD are infrequent, suggesting a true separation between this disorder and classical IBD. Do IBS and lymphocytic colitis represent different responses to similar triggers? Will some of the 'inflamed' IBS subgroup be reclassified as part of the spectrum of lymphocytic colitis in the future? Will inflammation emerge as a common underlying factor in the pathogenesis of IBS? The answer to these and many questions must await further study of this fascinating area.

Electrical stimulation for gastroparesis

BACKGROUND

Gastroparesis is a disabling, and sometimes fatal, disease that often does not respond to medical treatment. This single-surgeon prospective study examines the safety and 6-month efficacy of electrical stimulation for the treatment of gastroparesis.

METHODS

Sixteen patients with medically refractory gastroparesis underwent laparoscopic implantation of an electrical stimulator device (Enterra Therapy, Medtronic, Minneapolis, MN, USA) consisting of a subcutaneous stimulator and two gastric wall leads. Gastric emptying scans (GES) confirmed the diagnosis of gastroparesis. Patients were evaluated preoperatively using a self-administered GI symptomatology questionnaire and RAND 36 Health Survey. Once patients were >6-months from implantation, a repeat GES was obtained and patients completed a postoperative GI symptomatology questionnaire and RAND 36 Health Survey. Ten of 16 patients in this case series were >6-months from implantation. One was lost to follow-up. An F-test was used to establish equality of standard deviations between the 16 patients evaluated preoperatively and the subset of 10 patients evaluated postoperatively. A Student's t-test was used to evaluate the significance of differences in pre- and postoperative results.

RESULTS

Average operating time was 117 min with no intraoperative complications. The majority of patients were discharged on postoperative day 1. There were two complications in the postoperative period. Patients experienced a significant decrease in nausea and vomiting as measured by the GI symptomatology questionnaire. Half of all patients no longer required gastric prokinetic medications and there was a subjective reduction of pyrosis, early satiety, and epigastric pain. A significant increase in quality of life as measured by the RAND 36 Health Survey was seen, and six of eight patients no longer demonstrated gastroparesis on GES.

CONCLUSION

Laparoscopic implantation of an electrical stimulation device is a safe and effective treatment by subjective and objective standards for the management of medically refractory gastroparesis.

Gastric Motility, Gastroparesis, and Gastric Stimulation

Gastroparesis is the most common disorder of gastric motility. It is frequently overlooked in clinical practice because the symptoms of gastroparesis are nonspecific. This article reviews normal and abnormal gastric motility, discusses the etiology and pathogenesis of gastroparesis, and provides an overview on new treatment options for gastroparesis, including gastric stimulation.

New management approaches for gastroparesis

Management of patients with gastroparesis is challenging. Although the syndrome has multiple causes and knowledge of the pathophysiology and natural history is far from complete, a number of common management principles can be applied. The relatively poor correlation between upper-gastrointestinal symptoms and disordered gastric emptying represents a major difficulty in the therapeutic approach, and evidence to support the efficacy of current management strategies is often suboptimal, especially in relation to long-term therapy. In this review, the common causes and pathophysiology of gastroparesis are summarized, the diagnostic approach considered, and the evidence to support medical and surgical therapies reviewed. These therapies include currently available prokinetic drugs, novel medical therapies, and the promising technique of gastric electrical stimulation.

Chronic gastric electrical stimulation for gastroparesis reduces the use of prokinetic and/or antiemetic medications and the need for hospitalizations

To investigate the effect of chronic gastric electrical stimulation (GES) on the daily use of prokinetics and antiemetics, hospitalizations, total symptom score (TSS), SF-36 status for health-related quality of life (HQOL), and gastric emptying of a solid meal, we evaluated 37 gastroparetic patients preoperatively and 1 year after undergoing GES implant. Prokinetic and antiemetic use was significantly reduced. Of 27 patients on at least one prokinetic at baseline, 8 were off at 1 year. Twenty-six patients requiring antiemetics before surgery decreased to 17. Mean TSS was significantly reduced and the reduction for patients off medications was significantly better than for patients still on medications. Overall SF-36 scores for HQOL were significantly improved, and patients off antiemetics had a significantly higher HQOL score than for patients on antiemetics at 1 year. Hospitalizations decreased from 50 +/- 10 days for the year prior to GES therapy to 14 +/- 3 days (P < 0.05). However, gastric emptying was not significantly improved. Conclusions are as follows. (1) Chronic GES significantly reduced the use of prokinetic/antiemetic medications and the need for hospitalization in gastropraretic patients, whose clinical and quality of life outcomes also significantly improved. (2) These data provide evidence of the positive economic impact of this new therapy on long-term clinical outcomes in gastroparetic patients not responding to standard medical therapy.

Disturbances of motility and visceral hypersensitivity in irritable bowel syndrome: biological markers or epiphenomenon

Motility and visceral hypersentitivity are regarded as the primary mechanisms of symptom development in irritable bowel syndrome(IBS). While a variety of motor abnormalities have been described throughout the gastrointestinal tract in IBS, their specificity and relationship to symptoms remain unclear. Visceral hypersensitivity is ubiquitous in functional gastrointestinal disease and is especially common in IBS. Again, however, its specificity for IBS has been questioned. Many factors, including stress and psychopathology,complicate the interpretation of these phenomena and new re-search suggests that mucosal inflammation and luminal factors may be more fundamental to the etiology of this common disorder.

Is gastric electrical stimulation superior to standard pharmacologic therapy in improving GI symptoms, healthcare resources, and long-term health care benefits?

CONTEXT

Severe upper gastrointestinal (GI) motor disorders, including gastroparesis (GP), can consume significant health care resources. Many patients are refractory to traditional drug therapy.

OBJECTIVE

To compare symptoms, healthcare resource utilization and costs in two groups of patients with the symptoms of GP: those treated via gastric electrical stimulation (GES) and those treated with traditional pharmacological agents in an intensive outpatient program (MED).

DESIGN

A long-term comparison of patients with devices (n = 9) vs intensive medical therapy (n = 9).

SETTING AND PATIENTS

A total of 18 eligible patients with the symptoms of GP reported for 1-year baseline and long-term treatment for 3 years.

INTERVENTIONS

Patients with the symptoms of GP were treated by a GES or intensive medical therapy (MED).

MAIN OUTCOME MEASURES

GP Symptoms, healthcare resource utilization using investigator-derived independent outcome measure score (IDIOMS) and total hospital (inpatient and outpatient) billing costs.

RESULTS

Gastrointestinal symptoms were significantly different from baseline (F = 3.03, P < 0.017) with GP patients treated via GES showing more sustained improvement over 36 months than those treated via MED. Healthcare resource usage, measured via the IDIOMS, significantly improved at 12, 24 and 36 month follow-up for GES patients (F = 10.49, P < 0.001), compared with patients receiving medical therapy, who demonstrated further deterioration. GP patients treated via GES also proved superior to medical therapy at 24 and 36 months with regard to decreased costs (F = 4.85, P < 0.001). Within group comparisons indicated significantly reduced hospital days for both patient groups; however, no statistical differences were noted between groups in terms of hospital days. Three of nine patients in the MED group died primarily from i.v. access related problems; none of the GES patients died.

CONCLUSION

We conclude that GES is more effective in improving long-term GI symptoms and costs, and decreasing use of healthcare resources than intensive medical therapy, in this sample of patients with the symptoms of GP followed for 3 years. Certain patients with GP form a high-risk group in terms of costs, quality of life, morbidity and mortality.

Review article: gastric emptying in functional gastrointestinal disorders

Although delayed gastric emptying has been described in several functional gastrointestinal disorders, and appears to be especially common in functional dyspepsia, the relationship of this finding to symptoms and basic pathophysiology is difficult to define. The delineation of the interactions between delayed gastric emptying, on the one hand, and symptom pathogenesis, on the other, has been hampered by several factors. These include the limitations of the methodology itself, the extent of overlap between the various functional disorders and the sensitivity of gastric emptying to factors external to the stomach, be they elsewhere within the gastrointestinal tract, in the central nervous system or in the environment. In many instances, delayed gastric emptying is an epiphenomenon, reflecting the overlap between inadequately defined functional syndromes, shared pathophysiology or the activation of physiological interactions between the various organs of the gut. In others, it may imply a truly diffuse motor disorder. The disappointments attendant on attempts to alleviate symptoms through approaches designed to accelerate gastric emptying should therefore not come as a surprise. Pending the definition of the true significance of delayed gastric emptying in all functional gastrointestinal disorders, caution should be exerted in the interpretation of this finding in a patient with functional symptoms.

American Gastroenterological Association technical review on the diagnosis and treatment of gastroparesis

This literature review and the recommendations herein were prepared for the American Gastroenterological Association Clinical Practice Committee. The paper was approved by the Committee on May 16, 2004, and by the AGA Governing Board on September 23, 2004.

Responsiveness and interpretation of a quality of life questionnaire specific to upper gastrointestinal disorders

BACKGROUND AND AIMS

The Patient Assessment of Upper Gastrointestinal Disorders-Quality of Life (PAGI-QOL) has been developed and validated to assess quality of life in gastroesophageal reflux disease, dyspepsia, and gastroparesis. The aim of this work was to assess responsiveness of the PAGI-QOL to clinical changes and provide guidance for the interpretation of score changes.

METHODS

The analysis was based on 2 observational multicenter, longitudinal, 8-week observation studies, one in the United States and one in 5 European countries. The Overall Treatment Effect scale completed by patients and clinicians at 8 weeks was used to define groups of improved, worsened, and stable patients. Responsiveness was assessed by describing the change in PAGI-QOL scores for each of these groups, comparing these changes over time, and calculating effect sizes and standardized response means. These data were used to define the minimal clinically important difference.

RESULTS

A total of 1736 patients with upper gastrointestinal disorders were analyzed. High sensitivity to change over time was demonstrated, with effect sizes and standardized response means in improved patients for the PAGI-QOL total score ranging from 0.79-1.41. A change of 0.4 for the PAGI-QOL total score might be considered as the minimal clinically important difference when comparing pretreatment and post-treatment PAGI-QOL total scores.

CONCLUSIONS

The PAGI-QOL questionnaire is a responsive and clinically relevant instrument for assessing quality of life in patients with upper gastrointestinal disorders.

Effect of high-frequency gastric electrical stimulation on gastric myoelectric activity in gastroparetic patients

The aim of this study was to investigate the effect of gastric electrical stimulation (GES) on gastric myoelectric activity (GMA) and to identify possible mechanisms that could help explain how high-frequency GES is effective in treating nausea and vomiting associated with gastroparesis. Fifteen gastroparetic patients who received high-frequency GES were enrolled. Two pairs of temporary pacing wires were implanted on the serosa of the stomach along the greater curvature during surgery for placement of the permanent stimulation device. Two-channel serosal recordings of GMA before and during GES were measured. A gastric emptying test and severity of nausea and vomiting were assessed at baseline and at 3 months of GES. Power spectral and cross correlation analyses revealed that impaired propagation of slow waves (50%), tachygastria (30%) and abnormal myoelectric responses to a meal (50%) were the main abnormalities observed at baseline. GES with a high frequency significantly enhanced the slow wave amplitude and propagation velocity, and resulted in a significant improvement in nausea and vomiting but did not entrain the gastric slow wave or improve gastric emptying after 3 months of GES.

Treatment of gastroparesis

Gastroparesis is a condition of impaired gastric motility that can be chronic and result in decreased quality of life and complete disability. Once the diagnosis of gastroparesis is established, the clinician's attention should immediately focus on restoring nutritional status, providing symptomatic relief from nausea and vomiting, and improving gastric motility. Combination therapy is the rule rather than the exception, and most patients require multiple prokinetic and antiemetic modalities for adequate symptom relief. Currently available medications are often inadequate to achieve therapeutic goals, and newer modalities, such as gastric electrical stimulation, which has been shown to decrease symptoms and improve quality of life, should be employed at a low threshold. Several novel therapeutic options are under investigation and may also become part of the routine treatment of gastroparesis.