Gastroparesis: pathogenesis, diagnosis and management

Machine learning-based prediction of gastroparesis risk following complete mesocolic excision

BACKGROUND

Gastroparesis is a major complication following complete mesocolic excision (CME) and significantly impacts patient outcomes. This study aimed to create a machine learning model to pinpoint key risk factors before, during, and after surgery, effectively predicting the risk of gastroparesis after CME.

METHODS

The study involved 1146 patients with colon cancer, out of which 95 developed gastroparesis. Data were collected on 34 variables, including demographics, chronic conditions, pre-surgery test results, types of surgery, and intraoperative details. Four machine learning techniques were employed: extreme gradient boosting (XGBoost), random forest (RF), support vector machine (SVM), and k-nearest neighbor (KNN). The evaluation involved k-fold cross-validation, receiver operating characteristic (ROC) analysis, calibration curves, decision curve analysis (DCA), and external validation.

RESULTS

XGBoost excelled in its performance for predictive models. ROC analysis showed high accuracy for XGBoost, with area under the curve (AUC) scores of 0.976 for the training set and 0.906 for the validation set. K-fold cross-validation confirmed the model's stability, and calibration curves indicated high predictive accuracy. Additionally, DCA highlighted XGBoost's superior patient benefits for intervention treatments. An AUC of 0.77 in external validation demonstrated XGBoost's strong generalization ability.

CONCLUSION

The XGBoost-fueled predictive model for post-surgery colon cancer patients proved highly effective. It underlined gastroparesis as a significant post-operative issue, associated with advanced age, prolonged surgeries, extensive intraoperative blood loss, surgical techniques, low serum protein levels, anemia, diabetes, and hypothyroidism.

Medication reconciliation enhances the accuracy of gastric emptying scintigraphy

BACKGROUND

Gastroparesis (GP) is a prevalent sensorimotor disorder characterized by delayed gastric emptying without mechanical obstruction, posing significant diagnostic challenges. Gastric emptying scintigraphy (GES) is the gold standard for diagnosing GP. However, its accuracy can be compromised by many medications that affect gastric motility. This study evaluates the impact of medication reconciliation on the diagnostic accuracy of GES.

RESULTS

A significant proportion of patients (75%) were on medications known to affect gastric motility. Recommendations for medication adjustments were communicated, with 30% non-adherence. Adjustments in GES interpretations were necessary for 20% of patients following comprehensive medication reviews. The involvement of radiopharmacists facilitated accurate diagnostic conclusions, underscoring the critical role of medication reconciliation in GES accuracy.

CONCLUSION

Medication reconciliation enhanced the accuracy of GES in diagnosing gastroparesis, emphasizing the need to integrate clinical pharmacy practices into nuclear medicine. This interdisciplinary approach not only improves diagnostic accuracy but also enhances patient safety, advocating for the adoption of such practices in the management of gastroparesis.

Initial experience and outcomes of per oral pyloromyotomy for the treatment of refractory gastroparesis

BACKGROUND

Gastroparesis can be a debilitating disease process for which durable treatment options are lacking. While dietary changes and pharmacotherapy have some efficacy, symptoms frequently recur and some patients progress to needing supplemental enteral feeding access. Per oral pyloromyotomy (POP) has been shown to be a durable minimally invasive treatment option for refractory gastroparesis with a low side effect profile, and therefore has been performed at this institution for the past 6 years.

METHODS

This was a retrospective case series of all patients who underwent a POP at a single institution over a 6-year period (2018-2023). Patient demographics, preoperative symptomatology and subsequent workup, postoperative complications, and symptom recurrence were collected and analyzed.

RESULTS

There were 56 patients included in the study. There was a 1.8:1 female:male ratio. The average patient age was 56 years old (range 23-85). The average duration of symptoms was 1-3 years. Thirty-eight percent of patients had undergone previous endoscopic therapy for gastroparesis (pyloric botox injection or pyloric dilation) and 16% of patients underwent multiple endoscopic therapies. Twenty-nine percent of patients were on a medication for gastroparesis. Past surgery was the most common gastroparesis etiology for POP (50% of patients). Diabetes (23%) and idiopathic (19%) were the other most common gastroparesis etiologies for POP. Nausea was the most common symptom at first follow-up (30%) but these patients continued to improve with 14% of patients continuing to endorse nausea at 6 months. Twenty-seven percent of patients developed symptom recurrence. Forty percent of patients with symptom recurrence underwent a repeat endoscopic or surgical therapy.

CONCLUSIONS

In this present study, POP leads to durable results in approximately 75% of patients with minimal complications. Furthermore, the majority of patients who do develop symptom recurrence do not require additional gastroparesis interventions.

Frequency-Specific Effects of Noninvasive Median Nerve Stimulation on Gastric Slow Wave Activity in Humans

OBJECTIVES

The present study explored the effects of different frequencies of noninvasive median nerve stimulation (nMNS) on two autonomic responses: gastric slow waves under water-loading condition and heart rate variability (HRV). To the best of our knowledge, this is the first study to document the effects of different frequencies of nMNS on gastric slow waves (GSW) in humans under 5-minute water-loading condition.

MATERIALS AND METHODS

Twenty healthy adult participants were fitted with a noninvasive body-surface gastric mapping, electrocardiogram (ECG), and a transcutaneous electrical nerve stimulation device and administered with four different nMNS frequencies (placebo-0 Hz, 40 Hz, 120 Hz, and 200 Hz) on four separate counterbalanced days. After the baseline and stimulation periods, a 5-minute water-load test was applied, and a post-water-load period also is recorded for ECG and GSW activity. Time-domain HRV parameters are analyzed with repeated-measures one-way analysis of variance (ANOVA) and a post hoc Tukey multiple comparison test. Parameters that failed normality tests underwent a Freidman test with a post hoc Dunn multiple comparison test. GSW data are analyzed with repeated-measures mixed-effects ANOVA.

RESULTS

In empty stomach (baseline vs stimulation), only the 40-Hz frequency statistically significantly (p = 0.0129) increased GSW amplitude in comparison with its own baseline. In full (distended) stomach, 40-Hz and 200-Hz stimulations showed a statistically significant difference (post hoc multiple comparison adjusted, p = 0.0016 and p = 0.0183, respectively) in the Gastric Rhythm Index in comparison with the change obtained by placebo stimulation (baseline vs poststimulation periods); 120-Hz nMNS showed a statistically significant difference (p = 0.0300) in the stress index in comparison with the decrease observed in the placebo group. However, 120-Hz nMNS did not induce a statistically significant change in gastric electrical activity compared to placebo stimulation. The nMNS did not follow the linear "dose-response" relationship between nMNS frequency and gastric/HRV parameters.

CONCLUSIONS

The 40-Hz and 200-Hz nMNS frequencies showed the most promising results in response to gastric distension, in addition to 40 Hz for an empty stomach. Further research is essential to explore the potential therapeutic effects of these frequencies on gastric diseases such as gastroparesis, gastroesophageal reflux disease, and functional dyspepsia that can be used in wrist wearables.

A global bibliometric and visualized analysis of the status and trends of gastroparesis research

BACKGROUND

Gastroparesis has a substantial impact on the quality of life but has limited treatment options, which makes it a public health concern. No bibliometric studies on gastroparesis have been published thus far. Thus, this article aims to summarize and analyze research hotspots to provide a reference for clinical researchers.

MATERIALS AND METHODS

Gastroparesis-related research articles were searched in the Web of Science Core Collection (WOSCC), and relevant information was extracted after screening. A total of 1033 documents were analyzed with the bibliometric method using Microsoft Excel, Citespace, and VOSviewer.

RESULTS

Overall, our search retrieved 1033 papers contributed by 966 research institutions from 53 countries. Since 1980, publications in this field have increased rapidly. United States (n = 645) and Temple University (n = 122) were the most productive country and institution, respectively. Parkman, with 96 publications, was the most prominent author.

CONCLUSIONS

Research hotspots in gastroparesis can be summarized into four domains: innovation in diagnostic modalities, change of oral therapeutic agents, choice of surgical interventions, and pathological mechanisms. Future research on gastroparesis should focus on the quality of life of patients, diagnostic techniques, pyloromyotomy, and transpyloric stent placement.

Treatment of postsurgical gastroparesis syndrome with Fu's subcutaneous needling: A case report

Postsurgical gastroparesis syndrome is a syndrome of significantly delayed gastric emptying in the absence of mechanical obstruction after surgery. We presented a case of 69-year-old male patient who suffered from progressive nausea, vomiting and stomach fullness, with a bloating abdomen ten days after laparoscopic radical gastrectomy for gastric cancer. Conventional treatments such as gastrointestinal decompression, gastric acid suppression therapy and intravenous nutritional support were administrated, but there were no obvious improvements in nausea, vomiting, abdominal distension of this patient. Fu's subcutaneous needling was performed once a day for three days, for a total of three treatments. After three days of Fu's subcutaneous needling intervention, he was free of symptoms of nausea, vomiting and stomach fullness. His gastric drainage volume reduced from 1000 ml per day to 10 ml per day. Upper gastrointestinal angiography showed normal peristalsis of remnant stomach. In this case report, Fu's subcutaneous needling showed a potential role of gastrointestinal motility enhancement and gastric drainage volume decrement, which provided a safe and convenient method in palliative care of postsurgical gastroparesis syndrome.

Prox2 and Runx3 vagal sensory neurons regulate esophageal motility

Vagal sensory neurons monitor mechanical and chemical stimuli in the gastrointestinal tract. Major efforts are underway to assign physiological functions to the many distinct subtypes of vagal sensory neurons. Here, we use genetically guided anatomical tracing, optogenetics, and electrophysiology to identify and characterize vagal sensory neuron subtypes expressing Prox2 and Runx3 in mice. We show that three of these neuronal subtypes innervate the esophagus and stomach in regionalized patterns, where they form intraganglionic laminar endings. Electrophysiological analysis revealed that they are low-threshold mechanoreceptors but possess different adaptation properties. Lastly, genetic ablation of Prox2 and Runx3 neurons demonstrated their essential roles for esophageal peristalsis in freely behaving mice. Our work defines the identity and function of the vagal neurons that provide mechanosensory feedback from the esophagus to the brain and could lead to better understanding and treatment of esophageal motility disorders.

A prediction nomogram for postoperative gastroparesis syndrome in right colon cancer: a retrospective study

PURPOSE

To investigate the high-risk factors for postoperative gastroparesis syndrome (PGS) in right colon cancer and to build a prediction nomogram for personalized prediction of PGS.

METHODS

Our study retrospectively analyzed 361 patients with right colon cancer who underwent right hemicolectomy at The First Hospital of Putian City in Fujian Province, China and who were hospitalized between January 2012 and July 2022. Multivariate logistic regression was used to determine the independent risk factors for PGS and to establish a nomogram model. Furthermore, discrimination, calibration, and clinical benefits were used to evaluate the model.

RESULTS

The multivariate logistic regression revealed that dissection of the subpyloric lymph nodes (No. 206 lymph node) (OR 5.242, P = 0.005), preoperative fasting blood glucose level (OR 3.708, P = 0.024), preoperative albumin level (OR 3.503, P = 0.020), and total operative time (OR 4.648, P = 0.014) were independent risk factors for PGS. Based on the above four factors, the area under the ROC curve (AUC) and C-index of the nomogram were 0.831. The prediction nomogram's calibration curve was closer to the ideal diagonal, and the Hosmer‒Lemeshow test indicated that the nomogram fit well (P = 0.399). Moreover, the decision curve analysis revealed that the model can present better clinical benefits when the threshold probability was between 1 and 28%, and the internal validation verified the dependability of the model (C-index = 0.948).

CONCLUSIONS

A risk prediction nomogram based on perioperative factors provided the physician with a simple, visual, and efficient tool for the prediction and management of PGS in right colon cancer.

Novel insights into the pathogenic impact of diabetes on the gastrointestinal tract

Type 2 and type 1 diabetes are common endocrine disorders with a progressively increasing incidence worldwide. These chronic, systemic diseases have multiorgan implications, and the whole gastrointestinal (GI) tract represents a frequent target in terms of symptom appearance and interdependent pathophysiological mechanisms. Metabolic alterations linked with diabetic complications, neuropathy and disrupted hormone homeostasis can lead to upper and/or lower GI symptoms in up to 75% of diabetic patients, with multifactorial involvement of the oesophagus, stomach, upper and lower intestine, and of the gallbladder. On the other hand, altered gastrointestinal motility and/or secretions are able to affect glucose and lipid homeostasis in the short and long term. Finally, diabetes has been linked with increased cancer risk at different levels of the GI tract. The presence of GI symptoms and a comprehensive assessment of GI function should be carefully considered in the management of diabetic patients to avoid further complications and to ameliorate the quality of life. Additionally, the presence of gastrointestinal dysfunction should be adequately managed to improve metabolic homeostasis, the efficacy of antidiabetic treatments and secondary prevention strategies.

Prevalence and clinical correlates of antinuclear antibody in patients with gastroparesis

BACKGROUND

Autoimmunity may play a role in the pathogenesis of gastroparesis in a subset of patients. Antinuclear antibody (ANA) testing is often used to screen for autoimmune disorders.

AIMS

1) Determine prevalence of a positive ANA in patients with gastroparesis; 2) Describe characteristics of idiopathic gastroparesis patients with positive ANA.

METHODS

Patients were assessed with gastric emptying scintigraphy (GES), symptom assessment via Patient Assessment of Upper GI Symptoms [PAGI-SYM], and blood tests-ANA, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP).

RESULTS

Positive ANA was seen in 148 of 893 (17%) patients with gastroparesis, being similar in idiopathic (16% of 536 patients), T1DM (16% of 162), T2DM (18% of 147), and postfundoplication (19% of 48 patients) gastroparesis. Among 536 patients with idiopathic gastroparesis, ANA titer 1:40-1:80 was seen in 33 (6%) patients, 1:160-1:320 in 36 (7%) patients, and ≥1:640 in 17 (3%) patients. Increasing ANA titer was associated with female gender (p = 0.05), Hispanic ethnicity (p = 0.02), comorbid rheumatoid arthritis (p = 0.02), systemic sclerosis (p = 0.004), and elevated ESR (p = 0.007). ANA positivity was associated with lower total GCSI (p = 0.007) and lower nausea/vomiting subscale (p = 0.0005), but not related to gastric emptying.

CONCLUSIONS

The prevalence of a positive ANA in patients with gastroparesis was high at ~17% and did not differ significantly based on etiology. In idiopathic patients, ANA positivity was associated with rheumatoid arthritis, systemic sclerosis, and elevated ESR. ANA-positive gastroparesis represents a subset who often have other autoimmune symptoms or disorders, but less severe nausea and vomiting.

Efficacy and safety of long-term transcutaneous electroacupuncture versus sham transcutaneous electroacupuncture for delayed gastric emptying after distal gastrectomy: study protocol for a randomized, patient-assessor blinded, controlled trial

Background

Delayed gastric emptying (DGE) after distal gastrectomy impacts patients’ nutritional status and quality of life. The current treatments of DGE seem unsatisfactory or need invasive interventions. It is unknown whether transcutaneous electroacupuncture (TEA) is effective in treating DGE.

Methods

A total of 90 eligible participants who underwent distal gastrectomy will be randomly allocated to either the TEA group (n = 60) or the sham transcutaneous electroacupuncture (sham-TEA) group (n = 30). Each participant will receive TEA on the bilateral acupoints of Zusanli (ST36) and Neiguan (PC6) for 4 weeks. The primary outcomes will be the residual rates of radioactivity in the stomach by gastric scintigraphy and total response rates. The secondary outcomes will be endoscopic features, autonomic function, nutritional and psychological status, serum examination, and quality of life (QoL). The adverse events will also be reported. The patients will be followed up 1 year after the treatment.

Discussion

The findings of this randomized trial will provide high-quality evidence regarding the efficacy and safety of long-term TEA for treating DGE after distal gastrectomy.

Trial registration

Chinese Clinical Trial Registry ChiCTR2000033965. Registered on 20 June 2020

Relationship Between Gastric Emptying Rate and Simultaneously Assessed Symptoms in Functional Dyspepsia

METHODS

During a GE test (breath test with ¹³C-octanoic acid labelled 250 kcal solid meal), the severity of 6 symptoms (postprandial fullness, epigastric pain and burning, bloating, nausea and belching) was assessed, every 15 min, before meal-intake and 4h postprandially. The sum of individual symptom scores generated the meal-related symptoms score; the sum of all symptoms generated overall meal-related symptom severity (OSS). Data were compared in patients with normal and delayed GE (cut-off T_1/2≥ 109 min). Data are shown as mean±SEM.

RESULTS

504 patients were included, of which 382 patients (67% female, age 43.8±0.8 years, BMI 23.3±0.2 kg/m²) had normal and 122 patients (77% female, age 42.7±1.5 years, BMI 23.2±0.6 kg/m²) had delayed GE. OSS tended to be higher in patients with delayed GE (81.8±3.4 vs. 99.5±7.1, p=.05). Only nausea was significantly higher in patients with delayed GE (11±0.8 vs. 16±1.6, p=.01). No correlations were observed between GE rate and any of the symptoms (OSS: r=0.06, p=.2; nausea: r=0.06, p=.1). The symptom severity time course showed a significant difference only for nausea, with increased severity ratings 90 min after the meal (p<.01) in delayed GE compared to normal GE patients.

CONCLUSION

The severity of symptoms in functional dyspepsia and idiopathic gastroparesis, even when assessed during the GE test meal, is not correlated to gastric emptying rate. (Ethics committee University Hospital of Leuven study number S55426).

Upper Gastrointestinal Motility, Disease and Potential of Stem Cell Therapy

Many gastrointestinal motility disorders arise due to defects in the enteric nervous system. Achalasia and gastroparesis are two extremely debilitating digestive diseases of the upper gastrointestinal tract caused in part by damage or loss of the nitrergic neurons in the esophagus and stomach. Most current pharmacological and surgical interventions provide no long-term relief from symptoms, and none address the cause. Stem cell therapy, to replace the missing neurons and restore normal gut motility, is an attractive alternative therapy. However, there are a number of hurdles that must be overcome to bring this exciting research from the bench to the bedside.

Esophageal High-Resolution Manometry for Diagnosing the Severity of the Chronic Intestinal Pseudo-Obstruction: A Case Series

BACKGROUND

Chronic intestinal pseudo-obstruction (CIPO) is a severe and refractory intestinal motility disorder. However, due to its rarity and difficult histological investigation, its pathophysiology has not been characterized.

AIM

Therefore, in this study, we aimed to determine the role of esophageal high-resolution manometry (HRM) in CIPO and the histological and clinical characteristics of the disease.

METHODS

Patients with CIPO were analyzed for clinical characteristics; histological findings; and clinical courses after therapeutic intervention. In addition, HRM was performed to determine the esophageal involvement.

RESULTS

Eleven patients were diagnosed with CIPO, and five required the long period of parenteral nutrition showing impaired esophageal motility including achalasia and absent contractility diagnosed with HRM. The four of these five cases showed acute onset of the CIPO following the triggering events of pregnancy, appendicitis, and surgery. In contrast, other six patients with normal or Jackhammer esophagus on HRM had moderate severity of CIPO with gradual onset. The histological analyses revealed that the loss of the intestinal neural ganglion cells and layers by inflammation, destruction, and atrophy are related to the severity of the clinical course of the disease and esophageal HRM findings of achalasia and absent contractility.

CONCLUSIONS

HRM may be useful to diagnose the severity of the clinical course and to determine the therapeutic options for CIPO.

Closure of Petersen's Space Lowers the Incidence of Gastric Food Retention after Distal Gastrectomy with Gastrojejunostomy in Gastric Cancer Patients

Purpose

Delayed gastric emptying usually manifests as gastric food retention. This study aimed to evaluate the incidence of gastric food retention after distal gastrectomy with gastrojejunostomy in gastric cancer patients and identify the risk factors for its development.

Materials and Methods

We retrospectively enrolled 245 patients who underwent distal gastrectomy with gastrojejunostomy for gastric cancer at Boramae Medical Center between March 2017 and December 2019. We analyzed the presence of gastric food residue via computed tomography (CT) scans at 3 and 12 months postoperatively and analyzed the risk factors that may influence the development of gastric food retention.

Results

CT scans were performed on 235 patients at 3 months and on 217 patients at 12 months postoperatively. In the group that received closure of Petersen's space, the incidence of gastric food retention was significantly low as per the 3- and 12-month postoperative follow-up CT scans (P=0.028 and 0.003, respectively). In addition, hypertension was related to gastric food retention as per the 12-month postoperative follow-up CT scans (P=0.011). No other factors were related to the development of gastric food retention. In the multivariate analysis, non-closure of Petersen's space (hazard ratio [HR], 2.54; 95% confidence interval [CI], 1.20–5.38; P=0.010) was the only significant risk factor for gastric food retention at 3 months postoperatively, while non-closure of Petersen's space (HR, 2.81; 95% CI, 1.40-5.64; P=0.004) and hypertension (HR, 2.30; 95% CI, 1.14–4.63; P=0.020) were both significant risk factors for gastric food retention at 12 months postoperatively.

Conclusions

Closure of Petersen's space has an effect on decrease the incidence of gastric food retention after distal gastrectomy with gastrojejunostomy in gastric cancer patients.

Assessment of pyloric sphincter distensibility and pressure in patients with diabetic gastroparesis

BACKGROUND

Recent studies have shown that pyloric distensibility is altered in 30-50% of gastroparetic patients but the number of diabetic patients included in prior reports has been small. The aim of the present study was to assess pyloric sphincter measurements in diabetic patients with gastroparesis and to determine whether diabetes characteristics were correlated to pyloric disfunction.

METHODS

Pyloric distensibility and pressure were measured using EndoFLIP^® system in 46 patients with diabetic gastroparesis (DGP) and compared with 21 healthy volunteers (HV), and 33 patients with idiopathic gastroparesis (IGP). Altered pyloric distensibility was defined as the measurement below 10 mm² /mmHg at 40 ml of inflation. In diabetic patients, blood glucose, glycated hemoglobin, duration, complications, and treatments were collected.

KEY RESULTS

Mean pyloric distensibility at 40 ml of inflation was lower in DGP and IGP groups with, respectively, 10.8 ± 0.9 mm² /mmHg and 14.8 ± 2.2 mm² /mmHg in comparison with the HV group (25.2 ± 2.3 mm² /mmHg; p < 0.005). 56.5% of patients had a decreased pyloric distensibility in the DGP group, 51.5% of patients in the IGP group, and 10% of patients in the HV group. No correlation was found between pyloric sphincter measurements and diabetes characteristics, including blood glucose, glycated hemoglobin, diabetes mellitus type, neuropathy, or GLP1 agonists intake.

CONCLUSION AND INTERFERENCES

Pyloric sphincter distensibility and pressure were altered both in diabetic and idiopathic gastroparesis. Pyloric sphincter distensibility was not correlated to diabetes parameters.

Rapid, non-invasive measurement of gastric emptying rate using transcutaneous fluorescence spectroscopy

Gastric emptying rate (GER) signifies the rate at which the stomach empties following ingestion of a meal and is relevant to a wide range of clinical conditions. GER also represents a rate limiting step in small intestinal absorption and so is widely assessed for research purposes. Despite the clinical and physiological importance of gastric emptying, methods used to measure GER possess a series of limitations (including being invasive, slow or unsuitable for certain patient populations). Here, we present a new technique based on transcutaneous (through-the-skin) fluorescence spectroscopy that is fast, non-invasive, and does not require the collection of samples or laboratory-based analysis. Thus, this approach has the potential to allow immediate reporting of clinical results. Using this new method, participants receive an oral dose of a fluorescent contrast agent and a wearable probe detects the uptake of the agent from the gut into the blood stream. Analysis of the resulting data then permits the calculation of GER. We compared our spectroscopic technique to the paracetamol absorption test (a clinically approved GER test) in a clinical study of 20 participants. Results demonstrated good agreement between the two approaches and, hence, the clear potential of transcutaneous fluorescence spectroscopy for clinical assessment of GER.

Practical management approach to gastroparesis

Gastroparesis is a syndrome characterised by delayed gastric emptying in the absence of mechanical obstruction. Symptoms can include early satiety, abdominal pain, bloating, vomiting and regurgitation which cause significant morbidity in addition to nutritional deficits. There is a higher prevalence in diabetics and females, but the incidence in the Australian population has not been well studied. Management of gastroparesis involves investigating and correcting nutritional deficits, optimising glycaemic control and improving gastrointestinal motility. Symptom control in gastroparesis can be challenging. Nutritional deficits should be addressed initially through dietary modification. Enteral feeding is a second-line option when oral intake is insufficient. Home parenteral nutrition is rarely used, and only accessible through specialised clinics in the outpatient setting. Prokinetic medication classes that have been used include dopamine receptor antagonists, motilin receptor agonists, 5-HT₄ receptor agonists and ghrelin receptor agonists. Anti-emetic agents are often used for symptom control. Interventional treatments include gastric electrical stimulation, gastric per-oral endoscopic myotomy, feeding jejunostomy and gastrostomy/jejunstomy for gastric venting and enteral feeding. In this article we propose a framework to manage gastroparesis in Australia based on current evidence and available therapies.

Gastric ablation as a novel technique for modulating electrical conduction in the in vivo stomach

Gastric motility is coordinated by underlying bioelectrical "slow wave" activity. Slow wave dysrhythmias are associated with motility disorders, including gastroparesis, offering an underexplored potential therapeutic target. Although ablation is widely used to treat cardiac arrhythmias, this approach has not yet been trialed for gastric electrical abnormalities. We hypothesized that ablation can create localized conduction blocks and modulate slow wave activation. Radiofrequency ablation was performed on the porcine serosa in vivo, encompassing a range of parameters (55-85°C, adjacent points forming a line, 5-10 s/point). High-resolution electrical mapping (16 × 16 electrodes; 6 × 6 cm) was applied to define baseline and acute postablation activation patterns. Tissue damage was evaluated by hematoxylin and eosin and c-Kit stains. Results demonstrated that RF ablation successfully induced complete conduction block and a full thickness lesion in the muscle layer at energy doses of 65-75°C for 5-10 s/point. Gastric ablation may hold therapeutic potential for gastric electrical abnormalities in the future.NEW & NOTEWORTHY This study presents gastric ablation as a new method for modulating slow wave activation and propagation in vivo, by creating localized electrical conduction blocks in the stomach, validated by high-resolution electrical mapping and histological tissue analysis. The results define the effective energy dose range for creating conduction blocks, while maintaining the mucosal and submucosal integrity, and demonstrate the electrophysiological effects of ablation. In future, gastric ablation can now be translated toward disrupting dysrhythmic slow wave activation.

Metoclopramide nasal spray for management of symptoms of acute and recurrent diabetic gastroparesis in adults

Introduction: Gastroparesis (GP) is characterized by delayed gastric emptying in the absence of mechanical obstruction. About 75% of GP patients are females. Diabetes and idiopathic are the two commonest etiologies of GP. Up to two-thirds of the GP patients do not have significant symptom responses to medical therapies, and there is a paucity of available oral prokinetic agents with only one medication approved by the U.S. Food and Drug Administration (FDA) for this indication. The oral and parenteral formulations of metoclopramide were FDA approved in 1979 to treat symptoms of acute and recurrent diabetic GP. Now, more than 40 years later, a nasal preparation of metoclopramide (Gimoti^TM) was approved in June 2020 for the same indication.Areas covered: PubMed search using the keywords 'nasal metoclopramide' and 'diabetic gastroparesis.' This article aims to provide a concise review of the pharmacology, clinical efficacy, and tolerability of nasal metoclopramide.Expert opinion: The nasal formulation can be systemically absorbed without relying on the passage through a poorly emptying stomach, thus assuring the delivery of a therapeutic dose of metoclopramide, even during episodes of vomiting. Hence, metoclopramide nasal spray has the potential to be used during an acute flare, potentially avoiding hospitalizations.

Feasibility, safety, and long-term efficacy of gastric peroral endoscopic myotomy (G-POEM) for postsurgical gastroparesis: a single-center and retrospective study of a prospective database

BACKGROUND

Postsurgical gastroparesis is recognized as a gastrointestinal dysfunction syndrome following foregut surgery. Gastric peroral endoscopic myotomy (G-POEM) is suggested as a minimally invasive therapy for gastroparesis. But the long-term efficacy and safety of G-POEM in treating postsurgical gastroparesis are rarely explored.

METHODS

The primary outcomes included the symptomatic improvement based on gastroparesis cardinal symptoms index (GCSI) and the improvement of gastric emptying. The secondary outcomes included the improvement of gastroesophageal reflux symptoms and complications of G-POEM.

RESULTS

The severity of postsurgical gastroparesis was not associated with the onset time and the course of the disease. G-POEM significantly reduced GCSI throughout the follow-up period (p < 0.0001). For different anastomotic site, a significant improvement of GCSI was found at 6 month post-G-POEM (F_4,165 = 74.18, p < 0.0001). Subscale analysis of GCSI showed that nausea/vomiting, post-prandial fullness/early satiety, and bloating were improved significantly at 6-month post-G-POEM (p < 0.0001, respectively). Half-emptying and whole-emptying time were significantly shortened in patients with different anastomotic site post-G-POEM (half-emptying time: F_3,174 = 65.44, p < 0.0001; whole-emptying time: F_3,174 = 54.85, p < 0.0001). The emptying of ioversol was obviously accelerated after G-POEM. GCSI wasn't related to pyloric length, pyloric diameter, and thickness of pyloric wall. GERDQ was also used to evaluate the clinical efficacy of G-POEM. For each time points, GERDQ didn't differ significantly in patients with different anastomotic site (F_4,104 = 0.8075, p = 0.5231). For patients with different anastomotic site, GERDQ was improved significantly at different time points (F_4,104 = 59.11, p < 0.0001). The higher the esophageal anastomotic site was, the faster G-POEM improved the symptoms of gastroesophageal reflux. No one required re-hospitalization for any complication.

CONCLUSION

G-POEM is a minimally invasive therapy with long-term effectiveness and safety in treating postsurgical gastroparesis.

Normative values for gastric motility assessed with the 3D-transit electromagnetic tracking system

BACKGROUND

The Motilis 3D-Transit system allows ambulatory description of transit patterns throughout the gastrointestinal tract and offers an alternative method for studying gastric motility. We aimed to establish normative values for gastric motility assessed with the method.

METHOD

A total of 132 healthy volunteers ingested the 3D-Transit capsule for assessment of gastrointestinal transit times. Recordings from 125 subjects were used for definition of normative values. Forty-six subjects were studied on two consecutive days. Recordings were reanalyzed using newly developed software providing information on gastric emptying (GE) as well as contraction frequency and movement during gastric contractions.

RESULTS

The median GE time was 2.7 hours (range 0.1-21.2). In 89% of subjects, the capsule passed the pylorus within a postingestion period of 6 hours. The median frequency of gastric contractions was 3.1 per minute (range 2.6-3.8). The frequency was higher in women (3.2, range 2.7-3.8) than in men (3.0, range 2.6-3.5) and increased with age (0.004 per year) (P < .05). The median amplitudes were 35° (range 4-85) when based on rotation of the capsule and 11 mm (range 6-31) when based on capsule change in position. The rotation amplitude was higher in women and decreased with increasing BMI (P < .05). The position amplitude was also higher in women and increased with the amount of calories in the test meal, but decreased with increasing BMI and age (P < .05). Day-to-day variation (P > .05) was considerable while inter-rater variability was small.

CONCLUSION AND INFERENCES

We have established normative values for gastric motility assessed with the 3D-Transit system.

The Role of GI Peptides in Functional Dyspepsia and Gastroparesis: A Systematic Review

Functional dyspepsia (FD) and gastroparesis (GP) are common disorders of the upper gastrointestinal tract. The pathophysiology of these conditions is likely to be heterogenous, and factors such as altered motility, sensitivity and response to nutrition have been identified as putative underlying mechanisms. Motility, sensitivity as well as responses to nutrition can be influenced or mediated by peptide hormones and serotonin released from the gastrointestinal mucosa. This review summarizes the role of GI peptides in functional dyspepsia and gastroparesis. In most studies, the levels of somatostatin, ghrelin, and motilin did not differ between healthy volunteers and FD or GP patients, but higher symptom burden was often correlated with higher peptide levels. Ghrelin and motilin receptor agonists showed promising results in improvement of the gastric emptying, but the link with improvement of symptoms is less predictable. Serotonin agonists have a potential to improve symptoms in both FD and idiopathic gastroparesis. Drugs acting on the GLP-1 and on the PYY receptors deserve further investigation. There is a need for systematic large scale studies.

A Novel Approach in Spinal Cord Stimulation for Enhancing Gastric Motility: A Preliminary Study on Canines

Background/Aims

Gastroparesis is commonly seen in patients with diabetes and functional dyspepsia with no satisfactory therapies. Dysautonomia is one of the main reasons for the imbalanced motility. We hypothesized that spinal cord stimulation (SCS) is a viable therapy for gastroparesis via the autonomic modulation to improve gastric motility. The aim is to find an optimal method of SCS for treating gastroparesis.

Methods

Eight healthy-female dogs were implanted with a gastric cannula, a duodenal cannula, 2 multi-electrode spinal leads, and an implantable pulse generator. Gastric motility index (MI) was used to determine the best stimulation location/parameters of SCS. Optimized SCS was used to improve glucagon-induced gastroparesis.

Results

With fixed parameters, SCS at Thoracic 10 (T10) was found most effective for increasing gastric MI (37.8%, P = 0.013). SCS was optimized with different parameters (pulse width: 0.05–0.6 msec, frequency: 5–500 Hz, motor threshold: 30–90%) on T10. Our findings revealed that 0.5 msec, 20 Hz with 90% motor threshold at T10 were the best parameters in increasing MI. Glucagon significantly delayed gastric emptying, and this inhibitory effect was partially blocked by SCS. Gastric emptying at 120 minutes was 25.6% in the control session and 15.7% in glucagon session (P = 0.007 vs control), while it was 22.9% with SCS session (P = 0.041 vs glucagon). SCS with the optimal parameters was found to maximally enhance vagal activity and inhibit sympathetic activity assessed by the spectral analysis of heart rate variability.

Conclusions

SCS with optimized stimulation location and parameters improves gastric motility in healthy-dogs and accelerates gastric emptying impaired by glucagon via enhancing vagal activity.

Role of Gastric Emptying in Symptoms of Gastroparesis

The symptoms of gastroparesis, such as nausea, vomiting, postprandial fullness, early satiety and abdominal pain, frequently impair the quality of life of the affected individuals. The diagnosis of gastroparesis is made after structural etiologies are ruled out and an assessment of gastric function shows delayed gastric emptying. The role of the delay in gastric emptying in the pathogenesis of symptoms of gastroparesis has been debated, with some studies suggesting an association between delayed gastric emptying and the upper gastrointestinal symptoms, while others do not. The recent literature supports the importance of using reliable methods to assess gastric emptying, as delay in gastric emptying measured on a reliable test (4-h scintigraphy or breath test) is associated with the severity of upper gastrointestinal symptoms. In addition to measuring total gastric emptying, evaluation of regional gastric retention in the proximal and distal stomach and whole gut transit to assess small intestinal and colonic transit may provide additional useful information in patients with more generalized symptoms of gastrointestinal dysmotility.

Influence of Gastric Emptying and Gut Transit Testing on Clinical Management Decisions in Suspected Gastroparesis

INTRODUCTION

Gastric emptying scintigraphy (GES) or wireless motility capsules (WMCs) can evaluate upper gastrointestinal symptoms in suspected gastroparesis; WMC tests can also investigate lower gut symptoms. We aimed to determine whether these tests impact treatment plans and needs for additional diagnostic evaluation.

METHODS

In a prospective, multicenter study, 150 patients with gastroparesis symptoms simultaneously underwent GES and WMC testing. Based on these results, investigators devised management plans to recommend changes in medications, diet, and surgical therapies and order additional diagnostic tests.

RESULTS

Treatment changes were recommended more often based on the WMC vs GES results (68% vs 48%) (P < 0.0001). Ordering of additional test(s) was eliminated more often with WMC vs GES (71% vs 31%) (P < 0.0001). Prokinetics (P = 0.0007) and laxatives (P < 0.0001) were recommended more often based on the WMC vs GES results. Recommendations for prokinetics and gastroparesis diets were higher and neuromodulators lower in subjects with delayed emptying on both tests (all P ≤ 0.0006). Laxatives and additional motility tests were ordered more frequently for delayed compared with normal WMC colonic transit (P ≤ 0.02). Multiple motility tests were ordered more often on the basis of GES vs WMC findings (P ≤ 0.004). Antidumping diets and transit slowing medications were more commonly recommended for rapid WMC gastric emptying (P ≤ 0.03).

DISCUSSION

WMC transit results promote medication changes and eliminate additional diagnostic testing more often than GES because of greater detection of delayed gastric emptying and profiling the entire gastrointestinal tract in patients with gastroparesis symptoms.

TRANSLATIONAL IMPACT

Gastric scintigraphy and WMCs have differential impact on management decisions in suspected gastroparesis.

Gastric emptying scintigraphy results may influence the selection of the type of bariatric surgery: A cohort study

Bariatric surgery (BAS) may result in adverse outcomes that include appearance of gastrointestinal (GI) symptoms and/or failure to reach the weight reduction goal. This retrospective study tested the hypothesis that pre-operative gastric emptying (GE) abnormality is responsible for adverse post-surgical outcomes.Pre-operative GE was performed using the standard solid-meal GE scintigraphy (GES) in 111 consecutive patients (105 females and 6 males, mean age 46.2 years, range 20-70 years) who were evaluated for BAS. All underwent BAS - 93 had laparoscopic sleeve gastrectomy (LSG) and 18 had Roux-en-Y (ReY) gastric bypass. All had short-term (3-6 months) and long-term (up to 54 months) follow-up with review of symptoms, physical, and laboratory examinations. Chi-square analysis was performed. P-value < .05 was considered significant.Of the 111 patients, 83 had normal and 28 had abnormal pre-op GES. Sixty-eight were asymptomatic and 43 were symptomatic prior to surgery. Following surgery, 81 patients were asymptomatic and 30 were symptomatic at long-term follow-up. There was no significant difference between pre-op GE results and post-surgical adverse clinical outcome (p = ns). However, GES results seem to have guided the selection of surgical procedure significantly (P = .008).Pre-operative GE study was not a strong predictor of clinical outcome in BAS. Although, it influenced the type of surgery, as when the GES was abnormal, the patient was more likely to undergo ReY and when GES was normal, they favored LSG. Interestingly, many of our symptomatic patients at 6 months post-op were asymptomatic after long-term follow-up.

A Prospective Multicentric Postmarketing Observational Study to Characterize the Patient Population with Reduced Gastrointestinal Motility among Indian Diabetic Patients Receiving Itopride: The Progress Study

AIMS

This study was intended to assess the clinical profile of Indian diabetic patients with reduced gastrointestinal (GI) motility and to understand the role of itopride in addressing reduced GI motility (gastroparesis) symptoms and maintaining glycemic control.

MATERIAL AND METHODS

Patients with established reduced GI motility (scintigraphy), with varying degree of GI symptoms, receiving itopride 150 mg as per physicians' discretion were enrolled. Clinical profile, changes in symptom severity, glycemic indices, tolerability, and quality of life (QoL) after 8-week therapy (Patient assessment of upper GI disorders-QoL [PAGI-QoL]) were assessed.

RESULTS

Mean ± standard deviation age of enrolled population (n = 41) was 51.8 ± 12.39 years. Average duration of gastroparesis since underlying etiology was 67.7 ± 59.76 months. Common symptoms reported at baseline were bloating (68.3%), postprandial fullness (61.0%), nausea (51.2%), early satiety (41.5%), heartburn (39.0%), and vomiting (9.8%). Itopride therapy resulted in significant improvement in all symptoms (P < 0.001), which correlated with improved QoL (PAGI-QoL score reduction: 13.8 ± 11.48; P < 0.0001). Moreover, significant improvement in glycemic indicators was also evident (mean change from baseline hemoglobinA1c -0.5 ± 1.18; fasting plasma glucose -15.3 ± 43.61; postprandial plasma glucose -24.6 ± 57.20).

CONCLUSIONS

Itopride showed effectiveness in addressing symptoms of reduced GI motility in diabetics, with improved QoL. Significant improvement in glycemic indices was also evident posttreatment with itopride. This study sheds light on the role of prokinetics, not only for symptom relief but also for improving glycemic control in diabetic patients with reduced GI motility, thus providing a holistic approach for the management of these patients.

Efficacy and feasibility of G-POEM in management of patients with refractory gastroparesis: a systematic review and meta-analysis

Background and aim  Clinical management of patients with gastroparesis is challenging. Prior pyloric targeted procedures are either invasive or have questionable long-term efficacy. Gastric per-oral endoscopic myotomy (G-POEM) has been recently introduced as a minimally invasive approach. In this review, we performed a meta-analysis to evaluate the feasibility and efficacy of this technique in the management of patients with refractory gastroparesis. Methods  PubMed, Embase, and Scopus databases were searched to identify relevant studies published through May 2018. Weighted pool rates (WPR) of the clinical resolution were calculated. Pooled values of Gastroparesis Cardinal Symptom Index (GCSI) before and after the procedure were compared. Pooled difference in means comparing gastric emptying before and after the procedure was calculated. Fixed or random effect model was used according to the level of heterogeneity. Results  Seven studies with 196 patients were included in the meta-analysis. The mean value of procedure duration was 69.7 (95 % confidence interval [95 % CI]: 39 - 99 minutes) and average estimate of hospital stay was 1.96 (95 % CI: 1.22 - 2.95) days. The WPR for clinical success was 82 % (95 % CI: 74 % - 87 %, I ²  = 0). Compared with pre-procedure GCSI values, mean values of GCSI were reduced significantly at 5 days (-1.57 (95 % CI:-2.2,-0.9), I ²  = 80 %) ( P  < 0.001). Mean values of gastric emptying were significantly decreased 2 - 3 months after the procedure (-22.3 (95 %CI: -32.9, - 11.6), I ²  = 67 %) ( P  < 0.05). Conclusion  Due to the high rate of clinical success and low rate of adverse events, G-POEM should be considered in management of refractory gastroparesis.

Regional gastrointestinal pH profile is altered in patients with type 1 diabetes and peripheral neuropathy

BACKGROUND

Gastrointestinal (GI) symptoms, such as nausea and bloating, are common in people with type 1 diabetes (T1DM). Autonomic dysfunction can lead to changes in the GI secreto-motor function which can be associated with GI symptom development. We hypothesized that regional pH profiles in T1DM differs from health and would be associated with objective physiological/clinical markers.

METHODS

Forty-seven T1DM with confirmed diabetic sensory peripheral neuropathy and 41 healthy age-matched subjects underwent standardized wireless motility capsule testing. T1DM completed the gastroparesis cardinal symptom index (GCSI) and the gastrointestinal symptom rating scale. Disease duration, glycemic control, insulin usage, and 24-hour heart rate variability testing were evaluated.

KEY RESULTS

In comparison to healthy subjects, gastric, and large bowel median pH were lower in T1DM (1.8 ± 1.6 vs 2.9 ± 1.5, P = 0.001 and 6.7 ± 0.6 vs 7.0 ± 0.5, P = 0.003, respectively). Additionally, change in pH across the pylorus was lower while change in pH across the ileocecal junction was higher in T1DM (5.2 ± 1.5 vs 5.8 ± 0.5, P = 0.003 and 1.8 ± 0.4 vs 1.3 ± 0.4, P < 0.0001, respectively). No difference was found in small bowel median pH. Gastric median pH was associated with small bowel transit time (r = 0.30, P = 0.049). Change in pH across the pylorus was negatively associated with fasting glycose (r = -0.35, P = 0.027). Small bowel median pH was associated with nausea (r = 0.42, P = 0.005) and small bowel transit time (r = 0.48, P = 0.0007). Large bowel median pH was associated with nausea (r = 0.35, P = 0.018) and the total GCSI score (r = 0.34, P = 0.023).

CONCLUSIONS AND INFERENCES

The GI pH profile in T1DM with DSPN is different from healthy subjects. Changes in pH profile may have important therapeutic implications and influence pharmacotherapeutic bioavailability.

Enteric neural stem cell therapies for enteric neuropathies

BACKGROUND

Enteric neuropathies exist as a wide range of human disorders which impact on gastrointestinal motility. Current standard therapies for enteric neuropathies are limited to surgical resection or manipulation (eg, myotomy) of affected gut segments or medical management including both therapy (eg, prokinetic pharmacotherapy) and support such as parenteral nutrition. However, such treatments often result in poor prognosis and significant morbidity. The current limitations in treatment options for enteric neuropathies underline the need for alternative approaches to treat these devastating diseases. Recent advances have highlighted the potential of enteric neural stem cells as a possible treatment option for regenerative medicine, in such cases.

PURPOSE

The purpose of this review is to provide an up-to-date synopsis of the enteric neural stem cell research field. Here, we review in detail the initial characterization of enteric neural stem cells, early preclinical studies validating their use in murine models through to the most recent findings of therapeutic rescue of diseased gut tissue. We additionally pose a number of questions regarding these recent findings which will need to be addressed prior to clinical translation of this exciting cellular therapeutic.

Bacterial overgrowth, dysbiosis, inflammation, and dysmotility in the Cystic Fibrosis intestine

Gastrointestinal disease in Cystic Fibrosis (CF) is caused by defective chloride and bicarbonate transport in intestinal cells leading to reduced intraluminal fluidity, increased mucous viscosity and consequently development of intestinal inflammation, dysbiosis and often times dysmotility. This triad is also referred to as the "CF gut". A diagnosis is mainly based on clinical observation and treatment is often times decided empirically. This review of the literature should provide CF caregivers with some tools to identify intestinal inflammation, dysbiosis and dysmotility as possible cause for their patient's gastrointestinal complaints and provide an overview of our current approach to its management.

Gastric per-oral endoscopic myotomy for refractory gastroparesis: a detailed description of the procedure, our experience, and review of the literature

BACKGROUND AND AIMS

Gastric per-oral endoscopic myotomy (G-POEM) was introduced four years ago as an investigational procedure for refractory gastroparesis. The safety and efficacy were currently evaluated. With our recent studies on G-POEM, we share our experience and knowledge through the discussion of a detailed description of the procedure and review of the literature. To our knowledge, this is the first systemic review on this new therapeutic endoscopic procedure.

METHODS

The indications and contraindications, various aspects of the procedure, and efficacy assessment are discussed based on our experience and current available data.

RESULTS

Preoperative preparation, detailed description of the procedure, post-procedural care, and results in the literature are presented. The procedure is safe and effective. 70-80% of patients have significant improvement in overall symptoms and quality of life in short-term (6 months) follow-up, as assessed by Gastric Cardinal Symptom Index and Short Form 36.

CONCLUSIONS

G-POEM is a feasible and effective procedure for refractory gastroparesis based on early and limited data. Well-designed prospective studies are expected to advance and evaluate this new procedure in the future.

Regional gastrointestinal contractility parameters using the wireless motility capsule: inter-observer reproducibility and influence of age, gender and study country

BACKGROUND

The wireless motility capsule concurrently measures temperature, pH and pressure as it traverses the gastrointestinal tract.

AIMS

To describe normative values for motility/contractility parameters across age, gender and testing centres.

METHODS

Healthy participants underwent a standardised wireless motility capsule assessment following an overnight fast and consumption of a meal of known nutritional content. Traces were divided into regions of interest and analysed using 2 software packages (MotiliGI and GIMS Data Viewer). Inter-observer agreement was independently assessed by 2 investigators.

RESULTS

Normative data for motility/contractility parameters (maximum amplitude, mean peak amplitude, contraction frequency and motility index) are presented for 107 individuals (62 male, median age 40 years, range 18-78). MotiliGI-Gastric, small bowel and colonic maximal contraction amplitude correlated with age (r = .24, P = .01; r = .22, P = .02; and r = .2, P = .04 respectively). Small bowel motility index was higher in females than males (150.4 ± 12 vs 122 ± 7.6, P = .04). Inter-observer agreement was excellent for transit times, pH and contractility/motility parameters. GIMS Data viewer-Gastric, small bowel and colonic log_e motility index correlated with the respective area under the contraction curve, total contractions, sum of amplitudes and contraction frequency (all r>.35, P < .0003) but not with transit times.

CONCLUSIONS

Our analysis provides normative data for motility/contractility parameters. Log motility index summarises a number of measures. In future, the measurement of contractile activity with the wireless motility capsule may potentially aid in the diagnosis of disease states such as visceral myopathic disorders.

Relating gastric scintigraphy and symptoms to motility capsule transit and pressure findings in suspected gastroparesis

BACKGROUND

Wireless motility capsule (WMC) findings are incompletely defined in suspected gastroparesis. We aimed to characterize regional WMC transit and contractility in relation to scintigraphy, etiology, and symptoms in patients undergoing gastric emptying testing.

METHODS

A total of 209 patients with gastroparesis symptoms at NIDDK Gastroparesis Consortium centers underwent gastric scintigraphy and WMCs on separate days to measure regional transit and contractility. Validated questionnaires quantified symptoms.

KEY RESULTS

Solid scintigraphy and liquid scintigraphy were delayed in 68.8% and 34.8% of patients; WMC gastric emptying times (GET) were delayed in 40.3% and showed 52.8% agreement with scintigraphy; 15.5% and 33.5% had delayed small bowel (SBTT) and colon transit (CTT) times. Transit was delayed in ≥2 regions in 23.3%. Rapid transit was rarely observed. Diabetics had slower GET but more rapid SBTT versus idiopathics (P ≤ .02). GET delays related to greater scintigraphic retention, slower SBTT, and fewer gastric contractions (P ≤ .04). Overall gastroparesis symptoms and nausea/vomiting, early satiety/fullness, bloating/distention, and upper abdominal pain subscores showed no relation to WMC transit. Upper and lower abdominal pain scores (P ≤ .03) were greater with increased colon contractions. Constipation correlated with slower CTT and higher colon contractions (P = .03). Diarrhea scores were higher with delayed SBTT and CTT (P ≤ .04).

CONCLUSIONS & INFERENCES

Wireless motility capsules define gastric emptying delays similar but not identical to scintigraphy that are more severe in diabetics and relate to reduced gastric contractility. Extragastric transit delays occur in >40% with suspected gastroparesis. Gastroparesis symptoms show little association with WMC profiles, although lower symptoms relate to small bowel or colon abnormalities.

Contractile Protein Expression and Phosphorylation and Contractility of Gastric Smooth Muscles from Obese Patients and Patients with Obesity and Diabetes

Ingested food is received, mixed, and ground into chyme by distinct gastric motility patterns. Diabetes impairs gastric muscle function, but the mechanisms underlying diabetes-induced gastric muscle dysfunction are unknown. Here, we compared the expression and phosphorylation of Ca²⁺ sensitization and contractile proteins in human gastric muscles from obese nondiabetic and diabetic patients. We also compared the spontaneous phasic contractions and the contractile responses evoked by electrical field stimulation of cholinergic motor neurons. Fundus and antrum muscles were obtained from sleeve gastrectomies and were used in in vitro myobath contractile studies and for capillary electrophoresis and immunodetection of γ-actin, CPI-17, pT38-CPI-17, MYPT1, pT853-MYPT1, pT696-MYPT1, myosin light chain (MYL9), pS19-MYL9, myosin light chain kinase (MYLK), protein phosphatase-1δ (PP1δ), and Rho-associated kinase (ROCK2). In diabetic fundus muscles, MYLK, ROCK2, and PP1δ expression was unchanged; MYPT1 and CPI-17 expression was decreased; and the pT853/MYPT1 and pT38/CPI-17 ratios, but not the pT696/MYPT1 ratio, were increased. Although MYL9 expression was increased, the pS19/MYL9 ratio was unchanged in diabetic fundus muscles. In diabetic antrum muscles, MYLK and MYL9 expression was unchanged, but ROCK2, CPI-17, and PP1δ expression was decreased. The pT38/CPI-17 ratio was unchanged, while the pS19/MYL9, pT853/MYPT1, and pT696/MYPT1 ratios were decreased, consistent with the reduced ROCK2 expression. The frequencies of spontaneous phasic contractions from nondiabetic and diabetic gastric fundus and antrum muscles did not significantly differ from each other, regardless of age, sex, or diabetic status. The fold increases in the contractions of diabetic fundus and antrum muscles in response to increased frequencies of electrical field stimulation were significantly lower compared to nondiabetic fundus and antrum muscles. The altered contractile responses and the protein expression and phosphorylation in gastric muscles of obese patients with diabetes illustrate the importance of understanding how smooth muscle Ca²⁺ sensitization mechanisms contribute to gastric motility.

Gastrointestinal Motility Problems in Critically Ill Patients

Gastrointestinal (GI) motility problems are common complications in critical care patients. GI problems contribute to an increased risk of morbidity and mortality. Toxic megacolon (TM) is a type of acquired megacolon categorized as a medical emergency and includes severe inflammation affecting all layers of the colon wall. The high incidence of GI complications in critically ill patients requires the critical care nurse to provide close monitoring of patients at risk and an acute awareness of the causation, signs and symptoms, and treatment of various GI motility disorders, including gastroparesis, ileus, and TM.

Transplantation of enteric nervous system stem cells rescues nitric oxide synthase deficient mouse colon

Enteric nervous system neuropathy causes a wide range of severe gut motility disorders. Cell replacement of lost neurons using enteric neural stem cells (ENSC) is a possible therapy for these life-limiting disorders. Here we show rescue of gut motility after ENSC transplantation in a mouse model of human enteric neuropathy, the neuronal nitric oxide synthase (nNOS^−/−) deficient mouse model, which displays slow transit in the colon. We further show that transplantation of ENSC into the colon rescues impaired colonic motility with formation of extensive networks of transplanted cells, including the development of nNOS⁺ neurons and subsequent restoration of nitrergic responses. Moreover, post-transplantation non-cell-autonomous mechanisms restore the numbers of interstitial cells of Cajal that are reduced in the nNOS^−/− colon. These results provide the first direct evidence that ENSC transplantation can modulate the enteric neuromuscular syncytium to restore function, at the organ level, in a dysmotile gastrointestinal disease model.

Isolated human and mouse enteric nervous system stem cells (ENSCs) are capable of integrating and promoting innervation of the mouse colon. Here the authors show that transplantation of mouse ENSCs into a mouse model of human enteric neuropathy restores colon motility.

Acute Slow Wave Responses to High-Frequency Gastric Electrical Stimulation in Patients With Gastroparesis Defined by High-Resolution Mapping

BACKGROUND AND AIMS

High-frequency gastric electrical stimulation (GES) has emerged as a therapy for gastroparesis, but the mechanism(s) of action remain unclear. There is a need to refine stimulation protocols for clinical benefit, but a lack of accurate techniques for assessing mechanisms in clinical trials, such as slow wave modulation, has hindered progress. We thereby aimed to assess acute slow wave responses to GES in gastroparesis patients using high-resolution (HR) (multi-electrode) mapping, across a range of stimulation doses achievable by the Enterra stimulation device (Medtronic Inc., MN, USA).

MATERIALS AND METHODS

Patients with medically refractory gastroparesis (n = 8) undergoing device implantation underwent intraoperative HR mapping (256 electrodes). Baseline recordings were followed by four protocols of increasing stimulation intensity, with washout periods. Slow wave patterns, frequency, velocity, amplitude, and dysrhythmia rates were quantified by investigators blinded to stimulation settings.

RESULTS

There was no difference in slow wave pattern, frequency, velocity, or amplitude between baseline, washout, and stimulation periods (all p > 0.5). Dysrhythmias included ectopic pacemakers, conduction blocks, retrograde propagation, and colliding wavefronts, and dysrhythmia rates were unchanged with stimulation off vs. on (31% vs. 36% duration dysrhythmic; p > 0.5). Symptom scores and gastric emptying were improved at 5.8 month follow-up (p < 0.05).

CONCLUSIONS

High-frequency GES protocols achievable from a current commercial device did not acutely modulate slow wave activity or dysrhythmias. This study advances clinical methods for identifying and assessing therapeutic GES parameters, and can be applied in future studies on higher-energy protocols and devices.

Per-Oral Pyloromyotomy (POP): An Emerging Application of Submucosal Tunneling for the Treatment of Refractory Gastroparesis

A growing body of literature supports the use of laparoscopic pyloroplasty as a minimally invasive treatment of refractory gastroparesis that has failed conservative measures and for benign gastric outlet obstruction. Endoscopic pyloric dilation, stent placement, and Botox have been described for similar indications, but often with transient or mixed results. Per-oral pyloromyotomy has recently been proposed as an endoscopic alternative to surgical pyloroplasty or pylormyotomy because it is less invasive by its nature and potentially more durable than current endoscopic treatments.

Is Gastroparesis Found More Frequently in Patients with Cystic Fibrosis? A Systematic Review

Cystic fibrosis (CF) is associated with different gastrointestinal motility disturbances and syndromes. We aim to assess gastric emptying in patients with CF compared to healthy controls by a systematic review of existing literature. Medical databases and abstracts from major gastroenterology and CF meetings were reviewed. Emptying times in CF patients were compared with healthy controls using random effects models. Subgroup analysis stratified results by age and diagnostic modality. Nineteen studies from 7 countries included 574 subjects (359 CF patients and 215 controls). Using pooled analysis frequency of gastroparesis was high (38%, 95% CI 30-45%) but results were highly dependent on the diagnostic modality. Delayed gastric emptying is more common in CF compared to general population. Scintigraphy identified rapid gastric emptying in a subgroup of CF patients, but this finding disappeared with adequate pancreatic enzyme replacement and after other diagnostic modalities were included.

Novel insights into the effects of diabetes on gastric motility

Recent data from the Diabetes Control and Complications Trial/Epidemiology of Diabetic Interventions and Complications cohort indicate that the disease burden of gastroparesis in diabetes remains high, consistent with the outcome of cross-sectional studies in type 1 and 2 diabetes. An improved understanding of the pathogenesis of diabetic gastroparesis at the cellular level has emerged in the last decade, particularly as a result of initiatives such as the National Institute of Health funded Gastroparesis Clinical Research Consortium in the US. Management of diabetic gastroparesis involves dietary and psychological support, attention to glycaemic control, and the use of prokinetic agents. Given that the relationship between upper gastrointestinal symptoms and the rate of gastric emptying is weak, therapies targeted specifically at symptoms, such as nausea or pain, are important. The relationship between gastric emptying and postprandial glycaemia is complex and inter-dependent. Short-acting glucagon-like peptide-1 agonists, that slow gastric emptying, can be used to reduce postprandial glycaemic excursions and, in combination with basal insulin, result in substantial reductions in glycated haemoglobin in type 2 patients.

Reprogramming of Gastric Motility with "Pulse Therapy" (Metoclopramide and Erythromycin) in Severe Gastroparesis

Gastroparesis is a very common condition, however many times it becomes difficult to manage even after long-term treatment due to multiple etiologies or improper therapy. Patients with severe gastroparesis are considered candidates for gastric electrical stimulants. The "Pulse Therapy" using metoclopramide and erythromycin to reprogram gastric motility can delay or even avoid the need for gastric electrical stimulants. This case report focuses on a patient with severe gastroparesis, who was considered for a gastric pacemaker implantation and was instead treated successfully with "Pulse Therapy." As a part of this regimen, he was given metoclopramide continuously for 3 months along with pulses of erythromycin for 10 days a month for 3 months. Patient recovered dramatically that he no longer remained a candidate for gastric pacemaker implantation. This case study emphasizes on how the proper use of prokinetic agents based on symptoms and gastric emptying study can reprogram the stomach motility in these patients with severe gastroparesis.