Gastric peroral endoscopic myotomy for management of refractory gastroparesis in patients with gastric neurostimulator devices: a multicenter retrospective case control study

BACKGROUND AND AIMS

Gastric neurostimulation (GNS) and gastric peroral myotomy (G-POEM), therapies for refractory gastroparesis, are associated with suboptimal outcomes. We studied the role of G-POEM as a salvage therapy in patients with refractory symptoms after GNS implantation.

METHODS

This was a multicenter, retrospective, matched case-control study. Consecutive patients with a GNS device and who underwent G-POEM as a salvage therapy for clinical failure (cases) and patients without GNS implantation and who underwent G-POEM for refractory gastroparesis (control) between October 2018 and August 2021 were included. The primary outcome was clinical success after G-POEM.

RESULTS

A total of 123 patients (mean age 45.7 ± 14.7 years; 88 female subjects [72%]) underwent G-POEM therapy during the study: 41 cases and 82 controls. Clinical success was achieved in 66% in the case group and 65% in the control group (P = .311), during a median total clinical follow-up time of 11.8 (interquartile range, 2.4-6.3) months. In the case group, the mean Gastroparesis Cardinal Symptom Index score decreased from 2.8 ± 1.8 to 1.5 ± 1.9 (P = .024), and gastric retention at 4 hours improved from 45% ± 25.8% to 16.6% ± 13.1% (P = .06). The mean delta improvement in the subscales of nausea/vomiting (1.3 ± .6 vs .9 ± 1.1, P = .044) and bloating (1.6 ± 1.3 vs 1.2 ± 1.4, P = .041) were significantly higher in cases than in controls.

CONCLUSIONS

Among patients with refractory symptoms after GNS, G-POEM can be a reasonable salvage therapy to provide further symptomatic relief with evidence of a potential additive effect of both G-POEM and GNS.

Gastroparesis and Gastroparesis Syndromes as Neuromuscular Disorders

Gastroparesis syndromes (GpS) are a spectrum of disorders presenting with characteristic symptoms increasingly recognized as being gastrointestinal (GI) neuromuscular disorders (NMDs). This review focuses on GpS as a manifestation of neurologic disorders of GI NMD. GpS can be associated with systemic abnormalities, including inflammatory, metabolic, and serologic disorders, as well as autoimmune antibodies via nerve and muscle targets in the GI tract, which can be treated with immunotherapy, such as intravenous immunoglobulin. GpS are associated with autonomic (ANS) and enteric (ENS) dysfunction. Disorders of ANS may interact with the ENS and are the subject of continued investigation. ENS disorders have been recognized for a century but have only recently begun to be fully quantified. Anatomic structural changes in the GI tract are increasingly recognized in GpS. Detailed descriptions of anatomic changes in GpS, and their correlation with physiologic findings, have opened a new era of investigation. The management of GpS, when viewed as GI NMD, has shifted the paradigms of both diagnosis and treatment. This article concludes with current approaches to GpS directed at underlying neuromuscular pathology.

AGA Clinical Practice Update on Management of Medically Refractory Gastroparesis: Expert Review

DESCRIPTION

Delayed gastric emptying on objective testing defines gastroparesis, but symptoms overlap with functional dyspepsia and do not correlate well with gastric emptying delay. This review outlines a strategy for defining, diagnosing, and managing refractory gastroparesis.

METHODS

The Best Practice Advice statements presented here were developed from review of existing literature combined with expert opinion to provide practical advice. Because this was not a systematic review, formal rating of the quality of evidence or strength of recommendations was not performed. BEST PRACTICE ADVICE.

A Systematic Review of the Therapeutic Role of Gastric Pacemakers in Adults With Gastroparesis

Gastroparesis or gastric stasis is the delayed transit of the ingested contents through the stomach in the absence of mechanical obstruction. It can have multiple etiologies, most commonly idiopathic (ID) and diabetic (DM). Gastroparesis can cause significant distress to patients as it leads to symptoms like intractable nausea and vomiting, weight loss, abdominal bloating, early satiety, etc. The pathogenesis is mainly thought to be due to the dysfunction of the gastric pacemaker cells, i.e., interstitial cells of Cajal (ICC), and their interaction with the other gastric motor function regulatory components. There are several proposed treatment options for gastroparesis. Despite that, most patients remain refractory to medical treatment and require additional interventions for symptomatic relief. One such intervention is gastric electrical stimulation or gastric pacemaker, which aids in improving gastric motility. We have searched PubMed, PubMed Central (PMC), Medline, Science Direct, and Google Scholar for articles pertaining to the use of gastric electrical stimulation in gastroparesis published in the last 10 years. The keywords used include "gastroparesis", "gastric stasis", "gastric pacemaker'', "gastric electrical stimulation", "nausea", "vomiting", "abdominal bloating", "gastric neuromodulation". We have finally included twelve studies that were the most relevant to our research question and met the quality assessment criteria. Exclusion criteria consisted of pediatric population studies, studies conducted on animals, books, and grey literature. Overall, these twelve studies helped evaluate the impact of gastric pacemakers on symptoms of gastroparesis like nausea, vomiting, weight loss, abdominal bloating, and quality of life. We found that most studies favored gastric pacemakers, improving the incidence of nausea and vomiting in patients with gastroparesis. There was a marked improvement in the BMI as well. On the other hand, most open-labeled studies showed improved quality of life and Gastroparesis Cardinal Symptom Index (GCSI) scores, while randomized controlled trials and meta-analyses did not reflect the same result. In addition, some other parameters improved with gastric pacemakers, Inflammatory markers, insulin levels (especially in diabetics), and the number of hospitalizations. In conclusion, gastric pacemaker is a potential treatment option for patients with medically refractory gastroparesis. As noted from the results of our study, nausea/vomiting, weight loss, and overall GCSI scores have shown marked improvement with gastric electrical stimulation (GES). Nevertheless, more extensive research is needed to understand better the full extent of this device's use as a viable treatment option for patients suffering from gastroparesis.

Gastric electrical stimulation improves symptoms and need for supplemental nutrition in children with severe nausea and vomiting: A ten-year experience

BACKGROUND

Gastric electrical stimulation (GES) is a promising therapy for children with severe nausea and vomiting, but information on long-term outcomes is limited. We sought to evaluate the long-term efficacy and safety of GES and to describe patient benefit and satisfaction.

METHODS

Using a prospective registry, we identified patients aged <21 years treated with GES at our institution between 2009 and 2019. Encounters were selected at baseline prior to GES and at follow-up at 1 month, 12 months, and the most recent visit. We compared symptoms, route of nutrition, and medication usage at baseline to follow-up timepoints. Factors associated with improvement were evaluated. We recorded complications and need for battery replacement. We contacted families to administer the Glasgow Children's Benefit Inventory (GCBI) and a parent satisfaction questionnaire.

KEY RESULTS

Eighty-five patients (68.2% female, median age 15.8 years) completed a trial of temporary GES due to severe nausea and vomiting. Seventy-seven (90.6%) had a positive response and underwent permanent stimulator placement. Use of tube feeding or parenteral nutrition (PN) decreased from 72.7% at baseline to 29.9% at the most recent follow-up (p < 0.001). Higher baseline vomiting severity was associated with the ability to stop supplemental nutrition by 1 month (p < 0.05). Fourteen patients (18.2%) had complications, primarily due to stimulator-associated discomfort, and 29 (37.7%) required battery replacement. Median GCBI was +52.1, indicating health-related benefit.

CONCLUSIONS AND INFERENCES

Children with severe nausea and vomiting treated with GES experienced significant and durable improvement in symptom severity and their ability to tolerate oral nutrition.

The Surgeon's Role in Gastric Electrical Stimulation Therapy for Gastroparesis

INTRODUCTION

Gastroparesis, which can be viewed as a syndrome featuring nausea, vomiting, and abdominal pain, and associated other symptoms and findings, is increasingly seen by surgeons. Gastroparesis is associated with a number of gastrointestinal anatomic and physiologic findings.

MATERIALS AND METHODS

This article reviews the use of bioelectric therapy of neuromodulation, via gastric electrical stimulation, for patients with drug refractory gastroparesis syndromes including surgical aspects of device placement and subsequent management.

RESULTS AND DISCUSSION

In addition to an overall approach to the placement and subsequent management of gastric electrical stimulation devices, several newer concepts are discussed. The role of pyloric dysfunction in gastroparesis is also discussed including how stimulation devices and pyloric therapies may be used in concert. The additions of full-thickness gastrointestinal biopsies along with other physiologic, including GI electrophysiology, as well as some serologic measures, are also discussed. In addition, evolving approaches and emerging technologies for bioelectric neuromodulation of the gastrointestinal tract are introduced.

CONCLUSIONS

Gastroparesis syndromes can be approached in a systematic manner based on known pathophysiology and when indicated can be helped with surgical therapies including neuromodulation.

Pathophysiology of Gastroparesis Syndromes Includes Anatomic and Physiologic Abnormalities

BACKGROUND

Factors underlying gastroparesis are not well defined.

AIMS

We hypothesized that multiple systems may be involved in patients with gastroparesis symptoms and performed a comparative physiologic study.

METHODS

We studied 43 consecutive eligible patients with gastroparetic symptoms categorized by GI symptoms, metabolic status, illness quantification, and gastric physiology. Patients were evaluated by two methods in each of five core areas: inflammatory, autonomic, enteric, electrophysiologic, and hormonal with abnormalities examined by correlations.

RESULTS

Patients had similar GI symptoms regardless of baseline gastric emptying or diabetic/idiopathic status, and all patients demonstrated abnormalities in each of the 5 areas studied. Nearly all patients presented with elevated markers of serum TNFα (88%) and serum IL-6 (91%); elevated cutaneous electrogastrogram frequency (95%); and interstitial cells of Cajal count abnormalities (inner: 97%, outer: 100%). Measures of inflammation correlated with a number of autonomic, enteric anatomy, electrophysiologic and hormonal abnormalities.

CONCLUSIONS

We conclude that patients with the symptoms of gastroparesis have multiple abnormalities, when studied by traditional, as well as newer, diagnostic assessments. Inflammation appears to be a fundamental abnormality that affects other organ systems in symptomatic patients. Future work on gastroparetic syndromes and their treatment may benefit from a focus on the diffuse nature of their illness, diverse pathophysiologic mechanisms involved, especially the possible causes of underlying inflammation and disordered hormonal status.

TRAIL REGISTRY

This study is registered with Clinicaltrials.gov under study # NCT03178370 https://clinicaltrials.gov/ct2/show/NCT03178370 .

Comparison of the Status of Interstitial Cells of Cajal in the Smooth Muscle of the Antrum and Pylorus in Diabetic Male and Female Patients with Severe Gastroparesis

Females dominate in the area of gastroparesis (GP), making up to 70–80% of these patients. One attractive hypothesis is that females have less smooth muscle reserve and thus less resilience to recover from an insult. Our aim was to investigate if there are gender differences in the number of interstitial cells of Cajal (ICC) in the antral and pyloric smooth muscle of diabetic (DM) patients with severe gastroparesis refractory to standard medical management. Full thickness antral and pyloric biopsies were obtained during surgery to implant a gastric electrical stimulation system and perform a pyloroplasty. Thirty-eight DM patients (66% females, n = 25; mean age 44) who failed medical therapies provided antral biopsies. Pyloric tissue samples were also collected from 29 of these patients (65% females, n = 19). Tissues were stained with H&E and c-Kit for the presence of ICC. ICC depletion was defined as less than 10 cells/HPF. In the antrum, 40% of females had significant ICC depletion, similar to 38% in males. In the pylorus, 68% of females had depletion of ICC, compared to 80% depletion in males. When combining both antral and pyloric smooth muscle regions, ICC depletion was similar in males (40%) when compared to females (38%). In diabetic patients with severe GP, females and males showed similar degrees of reduction in antral ICC, while more males had depletion of pyloric smooth muscle ICC compared to their female counterparts. Future larger studies should focus on whether differences in other smooth muscle biomarkers can be identified between males and females.

Role of Gastric Electrical Stimulation in the Treatment of Gastroparesis

Introduction: Gastric electrical stimulation (GES) is a surgically implanted treatment option for drug refractory gastroparesis syndromes. Evidence supporting use of GES and the pathophysiology of gastroparesis syndromes is not widely known. We conducted a descriptive review to elucidate the pathophysiology of gastroparesis syndromes, with particular focus on gastrointestinal neuromodulation and the known mechanisms of action of GES. Methods: A descriptive review of PubMed, Web of Science and Cochrane Library was conducted using the keywords gastric electrical stimulation, gastroparesis, nausea, vomiting, neuromodulation, gastroparesis syndromes, central nervous system, gastric pacing and electrical stimulation. Results: 1040 potentially relevant articles were identified, of which 34 were included. These studies explored various central and peripheral effects of GES, as well as its effect on quality of life, hospital stay, mortality and health-related costs. Conclusion: Although evidence supporting gastrointestinal (GI) electrical stimulation and GI neuromodulation use is not widely known, GES does seem to offer significant improvement in symptom control, quality of life and other effects to many patients. GES exerts its effects through multiple central and peripheral mechanisms and has potential to modify the natural history of disease. Future work on gastroparetic syndromes and their treatment might be better focused in terms of pathophysiologic mechanisms. Improving outcomes with specific neuromodulation therapies, like GES, may offer improvements in health for many patients with refractory upper gastrointestinal symptoms.

Gastroparesis syndromes: Response to electrical stimulation

BACKGROUND AND AIMS

Factors underlying gastroparesis are not well defined, nor is the mechanism of action of gastric electrical stimulation (GES). We hypothesized that GES acts via several mechanisms related to underlying disordered pathophysiology.

METHODS

We studied 43 consecutive eligible patients with gastroparetic symptoms, previously evaluated by two methods in each of five core areas: inflammatory, autonomic, enteric, electrophysiologic, and hormonal; and also categorized by GI symptoms, metabolic status, illness quantification, and gastric physiology. We then studied 41 patients who underwent temporary GES for 5-7 days. Thirty-six of those patients were implanted and 30 were followed up at 6 months after permanent GES.

RESULTS

In previous but separately reported work, patients had similar GI symptoms regardless of baseline gastric emptying or diabetic/idiopathic status and all patients demonstrated abnormalities in each of the five areas studied. After GES, patients showed early and late effects of electrical stimulation with changes noted in multiple areas, categorized by improvement status.

CONCLUSION

Patients with symptoms of gastroparesis have multiple abnormalities, including systemic inflammation and disordered hormonal status. GES affects many of these abnormalities. We conclude electrical stimulation improves symptoms and physiology with (a) an early and sustained anti-emetic effect; (b) an early and durable gastric prokinetic effect in delayed emptying patients; (c) an early anti-arrhythmic effect that continues over time; (d) a late autonomic effect; (e) a late hormonal effect; (f) an early anti-inflammatory effect that persists; and (g) an early and sustained improvement in health-related quality of life. This study is registered with Clinicaltrials.gov under study # NCT03178370 (https://clinicaltrials.gov/ct2/show/NCT03178370).

Gastroparesis and Functional Dyspepsia: A Blurring Distinction of Pathophysiology and Treatment

Gastroparesis and functional dyspepsia are 2 of the most common gastric neuromuscular disorders. These disorders are usually confused, having both similarities and differences. The pathophysiology of these disorders involves abnormal gastric motility, visceral hypersensitivity, mucosal inflammation, and various cellular changes. Both disorders have similar symptoms such as epigastric pain or discomfort, early satiety, and bloating. If patients suspected of having either gastroparesis or functional dyspepsia present with upper gastrointestinal symptoms, they should undergo upper endoscopy to exclude an alternative organic cause. Although the gastric emptying rate is frequently assessed during the clinical workup of patients with gastroparesis or functional dyspepsia, the correlation between gastric emptying and the symptoms is generally poor. Once the diagnosis of gastroparesis or functional dyspepsia is made, treatment should focus on the predominant symptom. Recently, various treatment modalities have been developed and validated. Prokinetic agents are generally used as treatment for both gastroparesis and functional dyspepsia. Acid-suppressive therapy, Helicobacter pylori eradication, and use of drugs that enhance gastric accommodation are employed for functional dyspepsia. Psychoactive drugs are also effective in symptom control. For gastroparesis, antiemetic agents, ghrelin receptor agonists, and serotonergic agents are used aside from prokinetic agents. Acupuncture and gastric electrical stimulation can be attempted. In severe cases, endoscopic and surgical interventions are considered for symptom control.

Gastric Electrical Stimulator for Treatment of Gastroparesis

Patients with gastroparesis sometimes suffer from intractable nausea and vomiting, abdominal pain, and bloating, as well as a host of other symptoms that can often be difficult to control. Initially, patients are treated conservatively; some do well with conservative management but unfortunately some do not. Over the years, studies have shown the benefits of gastric electrical stimulation, which often results in symptomatic improvement and improvement in gastric emptying times. This article discusses the history of gastric electrical stimulation and its use in clinical practice to help those suffering from gastroparesis that is refractory to conservative medical management.

Pathophysiology of idiopathic gastroparesis and implications for therapy

OBJECTIVES

Idiopathic gastroparesis is a gastric motility disorder characterized by chronic upper gastrointestinal symptoms and delayed gastric emptying without an identifiable underlying condition. This review summarizes recent understanding of the pathophysiology and treatment of idiopathic gastroparesis.

MATERIALS AND METHODS

Structured literature search in the PubMed, Embase and ClinicalTrials.gov databases.

RESULTS

Idiopathic gastroparesis involves several alterations in gastric motility and sensation, including delayed gastric emptying, altered myoelectrical activity, impaired fundic accommodation, visceral hypersensitivity and disturbances in antropyloroduodenal motility and coordination. Multiple cellular changes have been identified, including depletion of interstitial cells of Cajal (ICC) and enteric nerves, as well as stromal fibrosis. The underlying cause of these changes is not fully understood but may be an immune imbalance, including loss of anti-inflammatory heme-oxygenase-1 positive (HO-1) macrophages. There is currently no causal therapy for idiopathic gastroparesis. The treatment ladder consists of dietary measures, prokinetic and antiemetic medications, and varying surgical or endoscopic interventions, including promising pyloric therapies. There are ongoing trials with several novel medications, raising hopes for future treatment.

CONCLUSIONS

Patients with idiopathic gastroparesis present several pathophysiological alterations in the stomach, where depletion of ICC is of special importance. Treatment is currently focused on alleviating symptoms through dietary adjustments, medication or surgical or endoscopic interventions.

Systematic review and meta-analysis: Gastric electrical stimulation for gastroparesis

BACKGROUND

Controlled trials of gastric electrical stimulation (GES) for gastroparesis reported no significant improvement in symptoms, while open label studies suggested substantial clinical benefits.

AIM

To determine if GES is effective in reducing symptoms in patients with gastroparesis.

METHODS

We searched PubMed and Embase for articles published in English (1990-2014) using "gastroparesis" as a search term restricted to "clinical trial". We included studies describing repeated patient-based symptom ratings before and during standardized treatments of at least one week duration.

RESULTS

Five studies randomly allocated patients to periods with or without GES. Total symptom severity (TSS) scores did not differ between these periods (0.17 [95% confidence interval: -0.06 to 0.4]; P=0.15). However, sixteen open label studies of GES showed a significant TSS decrease (2.68 [2.04-3.32]; Q=39.0; P<0.001). Other treatment modalities similarly improved TSS by 1.97 [1.5-2.44] for medical therapy (MED), by 1.52 [0.9-2.15] for placebo arms (PLA), and by 2.32 [1.56-3.06] for botulinum toxin (BTx). There were significant differences in baseline TSS ratings among these studies (GES: 6.28 [6.28-7.42]; MED: 4.76 [4.09-5.42]; PLA: 4.59 [3.77-5.42]; BTx: 6.02 [5.3-6.74]; Q=35.1; P<0.001). Meta-regression analysis showed these baseline differences to significantly impact TSS ratings during treatment (Q=71.8; P<0.001).

CONCLUSION

Independent of the treatment modality, baseline symptom severity impacts treatment results in gastroparesis. Considering the skewed population with refractory symptoms, regression to the mean likely contributes to the substantial discrepancies between the reported results of controlled and open label GES studies, raising questions about the use of GES outside of defined clinical trials.

Mini-laparotomy with Adjunctive Care versus Laparoscopy for Placement of Gastric Electrical Stimulation

We compared outcomes for two gastric electrical stimulation placement strategies, mini-laparotomy with adjunctive care (MLAC) versus laparoscopy without adjunctive care (LAPA). For electrode placement, the peritoneal cavity was accessed with either a single 2.5 to 3.0 cm midline incision (MLAC) or three trocar incisions (LAPA). For both groups, generator was placed subcutaneously over the anterior rectus sheath. For MLAC, adjunctive pain control measures were used for placement of both electrode and generator (transversus abdominus plane block). For LAPA, those that could not be completed by laparoscopy were converted to traditional open approach and kept in the analysis. MLAC (n = 128) resulted in shorter operative times than LAPA (n = 37) (median operative time: 87.5 vs 137.0 minutes, P ≤ 0.01). Hospital length of stay was also shorter for MLAC than for LAPA (median: 2.0 vs 3.0 days, P ≤ 0.01) without any increase in readmission rates to the hospital within 30 days of discharge (11.0 vs 16.2%, P = 0.39). After equalizing learning curves, these differences were even greater (median operative time: 84.5 vs 137.0 minutes, P < 0.01; median length of stay: 1.0 vs 3.0 days; P < 0.01) without increasing 30-day read-mission rates (9.1 vs 16.2%, P = 0.25). For implantation of gastric electrical stimulators, mini-laparotomy can result in improved outcomes when coupled with adjunctive pain control measures.

Gastric Electrical Stimulation and Sacral Electrical Stimulation: A Long-Term Follow-Up Study of Dual-Device Treatment

AIMS

The objective of this study was to investigate sacral electrical stimulation (SES) and gastric electrical stimulation (GES) by comparing upper and lower gastrointestinal (GI) and genitourinary (GU) symptoms and quality of life, before treatment and in the long term after treatment. We hypothesized that dual-device treatment would greatly improve upper and lower gastrointestinal and genitourinary symptoms, as well as quality of life.

METHODS

Fifty-four patients who underwent dual-device treatment (GES and SES) were enrolled in this study. Patients who had surpassed 24 months since the second-device insertion were included. Patients were evaluated before and after both devices were implanted and given a symptom questionnaire regarding their upper GI, lower GI, and GU symptoms and their quality of life.

RESULTS

With combined treatment, a statistically significant improvement was seen in upper GI, lower GI, and GU symptoms and quality of life. However, fecal incontinence and fecal urgency improvements did not reach statistical significance, likely due to the small sample size.

CONCLUSION

The implantation of two stimulators appears to be safe and effective to improve patients' quality of life for those with upper GI symptoms, bowel problems, and bladder dysfunction.

Long-term outcomes of gastric electrical stimulation in children with gastroparesis

BACKGROUND

Gastric electrical stimulation (GES) has been used in adults with gastroparesis. However its use has been limited in children. We describe the largest experience with GES in children with long-term outcomes.

METHODS

Data were collected on children who underwent GES over a 10-year period. Data regarding demographics, medical history, hospital course, and outcomes were collected and analyzed. Symptom scores (validated Likert scores) were compared using a paired Student's t test.

RESULTS

Overall, 97 patients underwent GES, and a majority were teenage Caucasian girls. Ninety-six had temporary GES (tGES), and 66 had improvement in their symptoms. A total of 67 underwent permanent implantation (pGES), and there was significant reduction in all individual symptoms (p<0.001) as well as the total symptom score (TSS) (p<0.0001) at 1, 6, 12, and >12 months. Recurrence of symptoms leading to device removal occurred in 7 cases. Forty-one patients had continued improvement in symptoms for over 12 months, with a mean follow-up of 3.5 years (range 1-9 years).

CONCLUSIONS

This study represents the largest experience of systematic application of GES in children. GES is a safe and effective therapy for selected children with intractable GP with continued symptomatic improvement at 1 year and beyond.

Temporary Endoscopic Stimulation in Gastroparesis-like Syndrome

Background/Aims

Gastroparesis-like syndrome (GLS) is defined as gastroparesis-like symptoms with normal gastric scintigraphy. While the efficacy of gastric electrical stimulation (GES) in gastroparesis is well known, the utility of GES in GLS is largely unknown. Our aim was to clarify the role of GES in GLS. We implanted consecutive patients with symptoms of gastroparesis with temporary gastric electrical stimulation and observed changes in gastric scintigraphy and total symptom score.

Methods

Five hundred and fifty-one patients suffering from symptoms of gastroparesis (nausea, vomiting, bloating/distension, anorexia/early satiety, and abdominal pain) with negative endoscopy underwent gastric scintigraphy with analysis of 1) solid radio-nuclide gastric emptying at 1, 2, and 4 hours (% remaining); 2) area under the gastric emptying curve (AUC) at 1, 2, and 4 hours; and 3) total gastric emptying test (GET) (the sum of 1, 2, and 4 hour values). Patients were stratified into: delayed gastric emptying, normal gastric emptying, and rapid gastric emptying (Appendix). Of the 551 patients in the larger cohort, 379 had implantation of temporary gastric electrical stimulation (tGES). Gastrointestinal symptoms and gastric emptying were com -pared pre and post tGES implantation.

Results

After tGES, 2 hour gastric retention decreased (P < 0.01) for the delayed patients, and increased (P < 0.001) for normal and rapid patients. These changes were accompanied by improvements (P < 0.001) in vomiting, nausea, and total symptom scores in all 3 subgroups.

Conclusions

Gastric electrical stimulation may be an effective therapy for treating the symptoms of gastroparesis with normal gastric emptying. Further exploration of endoscopic electrical stimulation as a treatment for gastroparesis-like symptoms with non-delayed gastric emptying is needed.

Gastroparesis in children

PURPOSE OF REVIEW

Gastroparesis is a disorder with delayed gastric emptying in the absence of mechanical obstruction. It is one of the more common dysmotilities that occur in the gastrointestinal tract, and is thought to primarily affect adults. Pediatric cases of gastroparesis were considered rare; however, recent evidence suggests growing recognition in children and adolescents. Therefore, it is important for the pediatric caregiver to understand the condition and the treatment options available.

RECENT FINDINGS

The majority of patients are women, and presentation is usually with symptoms of persistent nausea, emesis, postprandial pain and bloating, and early satiety. Weight loss may occur in some cases, though this is not universal. The majority of cases are idiopathic, with diabetes mellitus the second most common cause.

SUMMARY

Treatment consists of symptomatic relief with medication to counteract the nausea, emesis, pain, bloating, gastroesophageal reflux, early satiety, and improve gastric emptying. Dietary modification is also used with small meals and avoidance of high fiber and fat-containing foods. Recalcitrant cases of gastroparesis require the use of additional approaches such as jejunal feeds, intrapyloric botulinum toxin, gastric emptying procedures such as pyloroplasty, and gastric electrical stimulation. We will review these options in this article.

Surgical approaches to treatment of gastroparesis: gastric electrical stimulation, pyloroplasty, total gastrectomy and enteral feeding tubes

Gastric electrical stimulation (GES) is neurostimulation; its mechanism of action is affecting central control of nausea and vomiting and enhancing vagal function. GES is a powerful antiemetic available for patients with refractory symptoms of nausea and vomiting from gastroparesis of idiopathic and diabetic causes. GES is not indicated as a way of reducing abdominal pain in gastroparetic patients. The need for introducing a jejunal feeding tube means intensive medical therapies are failing, and is an indication for the implantation of the GES system, which should always be accompanied by a pyloroplasty to guarantee accelerated gastric emptying.

The stomach-brain axis

The stomach has distinct functions in relation to the ingestion and handling of solids and liquids. These functions include storage of the food before it is gradually emptied into the duodenum, mechanical crushing of larger food particles to increase the surface area, secretion of an acidic enzyme rich gastric juice and mixing the ingested food with the gastric juice. In addition, the stomach 'senses' the composition of the gastric content and this information is passed via the vagal nerve to the lateral hypothalamus and the limbic system, most likely as palatability signals that influence eating behaviour. Other sensory qualities related to the stimulation of gastric tension receptors are satiety and fullness. Receptors that respond to macronutrient content or gastric wall tension influence appetite and meal related hormone responses. The ingestion of food - in contrast to an infusion of nutrients into the stomach - has distinct effects on the activation of specific brain regions. Brain areas such as thalamus, amygdala, putamen and praecuneus are activated by the ingestion of food. Gastric nutrient infusion evokes greater activation in the hippocampus and anterior cingulate. The brain integrates these interrelated neural and hormonal signals arising from the stomach as well as visual, olfactory and anticipatory stimuli that ultimately influence eating and other behavioural patterns. Furthermore, there is now good evidence from experimental studies that gastric afferents influence mood, and animal studies point towards the possibility that gastric dysfunction may be a risk factor for mood disorders such as anxiety and depression. The stomach is also not only colonised by Helicobacter pylori but a large array of bacteria. While there is sufficient evidence to suggest that H. pylori may alter caloric intake and mood, the role of other gastric microbiome for the brain function is unknown. To address this appropriate targeted gastric microbiome studies would be required instead of widely utilised opportunistic stool microbiome studies. In summary, it is now well established that there are important links between the brain and the stomach that have significant effects on gastric function. However, the stomach also influences the brain. Disturbances in the crosstalk between the stomach and the brain may manifest as functional GI disorders while disturbances in the stomach-brain communication may also result in an altered regulation of satiety and as a consequence may affect eating behaviour and mood. These observations may enable the identification of novel therapies targeted at the gastroduodenum that positively alter brain function and treat or prevent conditions such as obesity or functional gastrointestinal disorders.