Ameliorating effect of transcutaneous electroacupuncture on impaired gastric accommodation induced by cold meal in healthy subjects

Acupuncture and moxibustion intervention in functional dyspepsia: Gastric and duodenal regulation

Functional dyspepsia (FD) is a brain-gut interaction disorder located in the stomach and duodenum, which has complex pathophysiological mechanisms, and there is no effective treatment for FD. Acupuncture and moxibustion have been proven to have definite and significant efficacy on FD. Focusing on the affected area and combined with the potential pathophysiology of FD, here we discuss the possible mechanisms of acupuncture and moxibustion in treating FD to guide future clinical and experimental research. We argue that the pathological causes of FD can be roughly divided into gastrointestinal dysfunction, duodenal low-grade inflammation, visceral hypersensitivity, and duodenal intestinal barrier and microbial imbalance. Correspondingly, the possible mechanisms of acupuncture and moxibustion in treating FD are elucidated from the perspective of how they improve gastric accommodation, regulate gastrointestinal motility, reduce gastric visceral sensitivity, regulate eosinophil-mast cell axis, inhibit low-grade inflammatory responses, and possibly regulate intestinal microbial homeostasis and duodenal barrier function through the microbiota-gut-brain axis. Although some evidence is still lacking, acupuncture remains a promising treatment for FD. In the future, it is necessary to conduct additional clinical and experimental research on acupuncture and moxibustion in treating FD to further explore their effects and mechanisms.

Effect and mechanism of needleless transcutaneous neuromodulation on gastrointestinal function after pancreaticoduodenectomy

BACKGROUND

Gastrointestinal motility disorders tend to develop after pancreaticoduodenectomy (PD). The objectives of this study were: (1) to investigate the impact of needleless transcutaneous neuromodulation (TN) on the postoperative recuperation following pancreaticoduodenectomy (PD), and (2) to explore the underlying mechanisms by which TN facilitates the recovery of gastrointestinal function after PD.

METHODS

A total of 41 patients scheduled for PD were randomized into two groups: the TN group (n = 21) and the Sham-TN group (n = 20). TN was performed at acupoints ST-36 and PC-6 twice daily for 1 h from the postoperative day 1 (POD1) to day 7. Sham-TN was performed at non-acupoints. Subsequent assessments incorporated both heart rate variation and dynamic electrogastrography to quantify alterations in vagal activity (HF) and gastric pacing activity.

RESULTS

1)TN significantly decreased the duration of the first passage of flatus (p < 0.001) and defecation (p < 0.01) as well as the time required to resume diet (p < 0.001) when compared to sham-TN;2)Compared with sham-TN, TN increased the proportion of regular gastric pacing activity (p < 0.01);3) From POD1 to POD7, there was a discernible augmentation in HF induced by TN stimulation(p < 0.01);4) TN significantly decreased serum IL-6 levels from POD1 to POD7 (p < 0.001);5) TN was an independent predictor of shortened hospital stay(β = - 0.349, p = 0.035).

CONCLUSION

Needleless TN accelerates the recovery of gastrointestinal function and reduces the risk of delayed gastric emptying in patients after PD by enhancing vagal activity and controlling the inflammatory response.

The Overlap Subgroup of Functional Dyspepsia Exhibits More Severely Impaired Gastric and Autonomic Functions

GOALS

A combination of multiple tests was introduced to noninvasively investigate the differences in pathophysiologies among functional dyspepsia (FD) subgroups, including postprandial distress syndrome (PDS), epigastric pain syndrome (EPS), and overlap.

BACKGROUND

It has not been extensively evaluated whether different pathophysiologies are involved in FD subgroups.

STUDY

This multicenter study included 364 FD patients fulfilling Rome IV criteria and 47 healthy controls. A combined noninvasive gastric and autonomic function test was performed: The electrogastrogram and electrocardiogram were recorded simultaneously in the fasting state and after a drink test. Symptoms after drinking were recorded using visual analog scale.

RESULTS

(1) Compared with HC, FD patients showed a decreased maximum tolerable volume (MTV) ( P <0.01) and percentage of normal gastric slow waves [normal gastric slow waves (%NSW)] ( P <0.01), and increased postdrinking symptoms, anxiety ( P <0.01), and depression ( P <0.01). The drink reduced %NSW in both FD patients and HC; however, the effect was more potent in patients. (2) The PDS and overlap groups displayed a reduced MTV ( P <0.05). The overlap group exhibited a higher symptom score at 30 minutes after drinking, and higher anxiety and depression scores, and a higher sympathovagal ratio than the EPS ( P <0.05 for all) and PDS ( P <0.01 for all). (3) In the PDS subgroup, the MTV, postprandial sympathovagal ratio, and depression were associated with the overall dyspepsia symptom scale (DSS, P =0.034, 0.021, 0.043, respectively). No significant associations were found in the other 2 subgroups.

CONCLUSIONS

The combination of multiple tests can detect pathophysiological abnormities in FD patients. Overall, patients with overlap symptoms display more severe pathophysiologies.

Non-invasive neuromodulation: an emerging intervention for visceral pain in gastrointestinal disorders

Gastrointestinal (GI) disorders, which extend from the esophagus to the anus, are the most common diseases of the GI tract. Among these disorders, pain, encompassing both abdominal and visceral pain, is a predominant feature, affecting the patients' quality of life and imposing a substantial financial burden on society. Pain signals originating from the gut intricately shape brain dynamics. In response, the brain sends appropriate descending signals to respond to pain through neuronal inhibition. However, due to the heterogeneous nature of the disease and its limited pathophysiological understanding, treatment options are minimal and often controversial. Consequently, many patients with GI disorders use complementary and alternative therapies such as neuromodulation to treat visceral pain. Neuromodulation intervenes in the central, peripheral, or autonomic nervous system by alternating or modulating nerve activity using electrical, electromagnetic, chemical, or optogenetic methodologies. Here, we review a few emerging noninvasive neuromodulation approaches with promising potential for alleviating pain associated with functional dyspepsia, gastroparesis, irritable bowel syndrome, inflammatory bowel disease, and non-cardiac chest pain. Moreover, we address critical aspects, including the efficacy, safety, and feasibility of these noninvasive neuromodulation methods, elucidate their mechanisms of action, and outline future research directions. In conclusion, the emerging field of noninvasive neuromodulation appears as a viable alternative therapeutic avenue for effectively managing visceral pain in GI disorders.

Clinical Efficacy and Mechanism of Transcutaneous Neuromodulation on Functional Dyspepsia

BACKGROUND AND AIMS

Prokinetics and proton pump inhibitors are first-line drugs for functional dyspepsia (FD) patients. However, no available treatment is effective for most FD patients, and the pathogenesis is still unclear. The purpose of this study was to investigate the therapeutic effect of transcutaneous neuromodulation (TN) on FD and its potential mechanisms.

MATERIALS AND METHODS

Fifty-seven FD patients were enrolled in the study and randomly divided into 3 groups (TN Neiguan (PC6) group, TN Zusanli (ST36) group, and sham TN group) that received corresponding treatment respectively for 4 weeks. Then, all the patients enrolled received TN PC6 combined with ST36 treatment for another 4 weeks. Dyspepsia symptom questionnaire, Medical outcomes study item short form health survey (SF-36), Hospital Anxiety and Depression Scale were used to assess the severity of symptoms. Gastric accommodation, gastric emptying rate, and related parameters of electrogastrogram were used to assess the pathophysiological mechanism of FD. The possible gastrointestinal hormonal mechanism involved was assessed by detecting serum ghrelin, neuropeptide Y, and vasoactive intestinal peptide. The possible duodenal inflammation mechanism involved was assessed by detecting duodenal mucosa.

RESULTS

TN treatment reduced the dyspepsia symptom score ( P <0.05) and improved the quality of life. After TN treatment, the gastric accommodation ( P <0.01), the gastric emptying rate ( P <0.01), and the percentages of preprandial ( P <0.05) and postprandial ( P <0.05) gastric slow waves (GSW) were increased. The proportions of preprandial ( P <0.05) and postprandial ( P <0.05) gastric electrical rhythm disorder were reduced. The double acupoint combination therapy further enhanced the therapeutic effect of single acupoint. In addition, the levels of ghrelin ( P <0.001) and neuropeptide Y ( P <0.001) were significantly increased, the level of vasoactive intestinal peptide ( P <0.001) was significantly decreased, and the total number of mast cells ( P <0.001) in the duodenal bulb was significantly decreased after double acupoints combination therapy.

CONCLUSIONS

TN treatment significantly improves the dyspepsia symptoms of FD patients and their quality of life. TN treatment increases the percentage of normal GSW, reduces the proportion of gastric electrical rhythm disorder, and improves the gastric accommodation and gastric emptying rate. The therapeutic effect of TN may be caused by regulating gastrointestinal hormone secretion and alleviating local inflammatory responses in duodenum. In addition, the improvement of TN on GSW was closely related to the decrease of bradygastria.

Clinical efficacy and mechanism of transcutaneous neuromodulation on ineffective esophageal motility in patients with gastroesophageal reflux disease

BACKGROUND

Esophageal motility disorder is one of the pathogenesis of gastroesophageal reflux disease (GERD). The clinical and functional relationship between the ineffective esophageal motility (IEM) and GERD have been found. PPI is a widely used drug of this diaease, but some patients have poor efficacy. The purpose of this study was to investigate the efficacy and possible mechanism of Transcutaneous Neuromodulation in these patients.

METHODS

Fifty-six patients with GERD with IEM were enrolled and randomly divided into two groups, one group was TN ST-36 group, the other group was sham TN group. The GERD questionnaire (GerdQ), quality of life score, MOS item short from health survey (SF-36), Hospital Anxiety and Depression Scale (HADS) were used to assess the severity of symptoms. High-resolution esophageal manometry (HRM) test was performed to assess low esophageal sphincter (LES) pressure and distal contractile integral (DCI). The heart rate variability (HRV) test was performed to assess autonomic nervous function.

KEY RESULTS

Compared with sham TN, chronic TN treatment decreased the GERD-Q score (p < 0.001). The anxiety score (p = 0.058) and depression score (p = 0.156) were decreased, but there were no statistical differences. Chronic TN treatment also significantly improved the quality of life of patients, mainly in physical function, physical pain, overall health, vitality, social function, emotional function, and mental health. Acute TN treatment increased the DCI (p < 0.001) and LES pressure (p < 0.001) significantly and decreased the combined percentage of failed and weak peristalsis (p < 0.001). Concurrently, acute TN enhanced vagal activity (p < 0.001).

CONCLUSIONS AND INFERENCES

IEM is an important link in the pathogenesis of GERD. Chronic TN treatment can significantly improve the clinical symptoms of patients. Acute TN treatment can significantly increase LES pressure and DCI and reduce the frequency of esophageal lost peristalsis and weak peristalsis. The improvement of esophageal motility in GERD patients with IEM by TN treatment may be related to the regulation of autonomic nervous function.

Transcutaneous Electrical Acustimulation Improves Irritable Bowel Syndrome With Constipation by Accelerating Colon Transit and Reducing Rectal Sensation Using Autonomic Mechanisms

INTRODUCTION

Slow colon transit and visceral hypersensitivity are recognized as major pathophysiological mechanisms in irritable bowel syndrome with constipation (IBS-C). However, there is a lack of therapies targeting both abdominal pain and colonic motility. This study was designed to investigate the long-term effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) in patients with IBS-C.

METHODS

Fifty-two patients with IBS-C were randomized into 2 groups: daily TEA for 4 weeks (n = 26) and daily sham-TEA for 4 weeks (n = 26). The number of complete spontaneous bowel movements per week (CSBMs/week, primary outcome), Irritable Bowel Syndrome Severity Scoring System, Patient Assessment of Constipation Quality of Life, visual analog scale (VAS) pain score, colonic transit time, and anorectal physiology were evaluated before treatment and at the end of the treatment. Colonic transit was assessed with radiopaque markers. Electrocardiograms were recorded for assessing autonomic functions.

RESULTS

(i) TEA improved constipation and abdominal pain. After the treatment, the number of CSBMs/week during the last week in the TEA group was higher than that in the sham-TEA group (3.5 ± 1.6 vs 2.3 ± 0.6, P = 0.002). Similar effects were also noted in the visual analog scale pain score ( P = 0.002) and Irritable Bowel Syndrome Severity Scoring System score ( P = 0.025). In addition, there was a significant improvement in the quality of life of patients with constipation. The Patient Assessment of Constipation Quality of Life total score was significantly decreased in the TEA group ( P = 0.004). (ii) Compared with sham-TEA, TEA improved colon transit ( P = 0.002) and increased the threshold of rectal sensation (desire to defecate, P = 0.004; maximum tolerability, P &lt; 0.001). (iii) TEA increased vagal activity, compared with sham-TEA ( P &lt; 0.05); at the end of the treatment, the vagal activity was significantly correlated with colon transit and the CSBMs/week.

DISCUSSION

TEA improves constipation and symptoms of IBS by accelerating colon transit and reducing rectal sensation, possibly mediated by using the autonomic mechanisms.

Low-frequency electrical stimulation promotes the recovery of gastrointestinal motility following gynecological laparoscopy (Review)

The rapid recovery of gastrointestinal transit is critical for clinical recovery following laparoscopic procedures, including gynecological laparoscopies (GLs). Rehabilitation interventions post-surgery may provide significant prevention against early post-operative gastrointestinal motility disorders and maid aid in the acceleration of post-operative recovery in patients undergoing GLs. Among others, low-frequency electrical stimulation (LFES) has been demonstrated to pronouncedly mitigate the symptoms caused by gastrointestinal motility disorders; thus, this has attracted increasing attention over the past decade. The present study aimed to present an overview of the efficacy and application of LFES in gastrointestinal motility recovery following GL procedures.

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

Transcutaneous Electrical Acustimulation Improved the Quality of Life in Patients With Diarrhea-Irritable Bowel Syndrome

BACKGROUND AND AIM

Patients with diarrhea-dominant irritable bowel syndrome (IBS-D) experience abdominal pain and reduced quality of life and need effective treatments. This study aimed to evaluate whether transcutaneous electrical acustimulation (TEA) at two acupuncture points, LI4 and ST36, could improve pain and quality of life of patients with IBS-D.

MATERIALS AND METHODS

A total of 42 patients with IBS-D who met the Rome IV criteria were randomly divided into two groups: TEA and sham-TEA. TEA was performed through acupoints Hegu (LI4) and Zusanli (ST36) for one hour twice daily for one month, using previously established parameters; sham-TEA was delivered in the same way as TEA but without actual electrical current stimulation.

RESULTS

The sham-TEA group showed a significantly higher rate of drop-out than the TEA group (29% vs 0%, p = 0.021). TEA, but not sham-TEA, significantly improved quality of life (before: 78.55 ± 9.62, after: 85.97 ± 9.49, p < 0.0001). Both TEA and sham-TEA reduced abdominal pain; however, TEA was more potent than sham-TEA (p = 0.014). The IBS symptom severity scale score was reduced by both TEA and sham-TEA. Autonomic functions assessed by plasma norepinephrine and pancreatic polypeptide were not altered with TEA, nor was interleukin 10 or interleukin 6.

CONCLUSIONS

TEA at LI4 and ST36 improves abdominal pain and quality of life of patients with IBS-D, probably mediated by mechanisms other than autonomic function or inflammatory cytokines.

Integrative Effects and Vagal Mechanisms of Transcutaneous Electrical Acustimulation on Gastroesophageal Motility in Patients With Gastroesophageal Reflux Disease

INTRODUCTION

Impaired esophageal and gastric motilities are known to contribute to symptoms of gastroesophageal reflux disease (GERD). However, there is a lack of GERD therapy, targeting both gastric and esophageal functions. This study was designed to investigate the effects of transcutaneous electrical acustimulation (TEA) on symptoms of GERD and gastroesophageal functions and possible mechanisms in patients with GERD.

METHODS

Thirty patients with GERD with ineffective esophageal motility were equally divided and randomized into a 4-week sham-TEA or 4-week TEA treatment. The GERD questionnaire (GerdQ), GERD health-related quality-of-life questionnaire, high-resolution esophageal manometry, a nutrient drink test, the electrogastrogram, and ECG were performed to assess the severity of reflux symptoms, low esophageal sphincter (LES) pressure, distal contractile integral (DCI), gastric accommodation, gastric slow waves (GSW), and autonomic functions, respectively.

RESULTS

Compared with sham-TEA, the 4-week TEA treatment significantly decreased the GerdQ score (P = 0.011) and GERD health-related quality of life (P = 0.028) and improved nutrient drink-induced fullness (P < 0.001) and belching (P < 0.001) in patients with GERD. Although only acute TEA significantly enhanced LES pressure (P < 0.05), both acute and chronic TEA remarkedly increased DCI (P < 0.05) and reduced the incidence of ineffective esophageal contractions during wet swallows (P = 0.02). In addition, chronic TEA significantly increased gastric accommodation and the percentage of postprandial normal GSW compared with sham-TEA and baseline. Concurrently, TEA-enhanced vagal activity (P = 0.02) and the vagal activity positively correlated with LES pressure (r = 0.528; P = 0.003) and DCI (r = 0.522; P = 0.003).

DISCUSSION

The TEA treatment performed in this study improves reflux-related symptoms, increases DCI, reduces the incidence of ineffective esophageal contractions during wet swallows, and improves gastric accommodation and slow waves. The improvement in GERD symptoms might be attributed to the integrative effects of TEA on these gastroesophageal functions mediated via the vagal mechanism.

Transcutaneous auricular vagal nerve stimulation improves functional dyspepsia by enhancing vagal efferent activity

This study was designed to investigate whether transcutaneous auricular vagal nerve stimulation (taVNS) would be able to improve major pathophysiologies of functional dyspepsia (FD) in patients with FD. Thirty-six patients with FD (21 F) were studied in two sessions (taVNS and sham-ES). Physiological measurements, including gastric slow waves, gastric accommodation, and autonomic functions, were assessed by the electrogastrogram (EGG), a nutrient drink test and the spectral analysis of heart rate variability derived from the electrocardiogram (ECG), respectively. Thirty-six patients with FD (25 F) were randomized to receive 2-wk taVNS or sham-ES. The dyspeptic symptom scales, anxiety and depression scores, and the same physiological measurements were assessed at the beginning and the end of the 2-wk treatment. In comparison with sham-ES, acute taVNS improved gastric accommodation (P = 0.008), increased the percentage of normal gastric slow waves (%NSW, fasting: P = 0.010; fed: P = 0.007) and vagal activity (fasting: P = 0.056; fed: P = 0.026). In comparison with baseline, 2-wk taVNS but not sham-ES reduced symptoms of dyspepsia (P = 0.010), decreased the scores of anxiety (P = 0.002) and depression (P < 0.001), and improved gastric accommodation (P < 0.001) and the %NSW (fasting: P < 0.05; fed: P < 0.05) by enhancing vagal efferent activity (fasting: P = 0.015; fed: P = 0.048). Compared with the HC, the patients showed increased anxiety (P < 0.001) and depression (P < 0.001), and decreased gastric accommodation (P < 0.001) and %NSW (P < 0.001) as well as decreased vagal activity (fasting: P = 0.047). The noninvasive taVNS has a therapeutic potential for treating nonsevere FD by improving gastric accommodation and gastric pace-making activity via enhancing vagal activity.NEW & NOTEWORTHY Treatment of functional dyspepsia is difficult due to various pathophysiological factors. The proposed method of transcutaneous auricular vagal nerve stimulation improves symptoms of both dyspepsia and depression/anxiety, and gastric functions (accommodation and slow waves), possibly mediated via the enhancement of vagal efferent activity. This noninvasive and easy-to-implement neuromodulation method will be well received by patients and healthcare providers.

Effects of electroacupuncture on stress-induced gastric dysrhythmia and mechanisms involving autonomic and central nervous systems in functional dyspepsia

Electroacupuncture (EA) is widely used as an effective method to treat stress-related disorders. However, its mechanisms remain largely unknown. The aim of this study was to investigate the effects and mechanisms of EA on gastric slow wave (GSW) dysrhythmia and c-Fos expression in the nucleus of the solitary tract (NTS) induced by stress in a rodent model of functional dyspepsia (FD). Rats in the neonatal stage were treated using intragastric iodoacetamide. Eight weeks later, the rats were implanted with electrodes in the stomach for the measurement of GSW and electrodes into accupoints ST36 for EA. Autonomic functions were assessed by spectral analysis of heart rate variability. Rats were placed for 30 min in a cylindrical plastic tube for acute restraint stress. The involvement of a central afferent pathway was assessed by measuring c-Fos-immunoreactive cells in the NTS. 1) EA normalized restraint stress-induced impairment of GSW in FD rats. 2) EA significantly increased vagal activity (P = 0.002) and improved sympathovagal balance (P = 0.004) under stress in FD rats. 3) In FD rats under restraint stress, plasma norepinephrine concentration was increased substantially (P < 0.01), which was suppressed with EA. 4) The EA group showed increased c-Fos-positive cell counts in the NTS compared with the sham EA group (P < 0.05) in FD rats. Acute restraint stress induces gastric dysrhythmia in a rodent model of FD. EA at ST36 improves GSW under stress in FD rats mediated via the central and autonomic pathways, involving the NTS and vagal efferent pathway.

Transcutaneous Electrical Acustimulation Improves Gastrointestinal Disturbances Induced by Transcatheter Arterial Chemoembolization in Patients With Liver Cancers

BACKGROUND

Gastrointestinal (GI) disturbances occur in patients who receive chemotherapy via transcatheter arterial chemoembolization (TACE) and could last for an extended period of time in some cases. Antiemetic drugs have a potential risk of developing hepatic failure and are ineffective for delayed nausea and emesis. Transcutaneous electrical acustimulation (TEA) has recently been reported to exert antiemetic and prokinetic effects, but it is unknown whether it has an ameliorating effect on TACE-induced GI disturbances.

AIM

This study was designed to evaluate effects and mechanisms of noninvasive TEA on GI symptoms in patients treated with TACE.

MATERIALS AND METHODS

Seventy-four patients with liver cancers (eighteen female; age 63.4 ± 1.1 years) scheduled for TACE were randomized to TEA (n = 37) or sham-TEA (n = 37). TEA was performed via acupoints, ST36 and PC6 using parameters previously optimized for GI motility (1 h, bid) from the postoperative day 0 (POD0) to POD2. Sham-TEA was performed using the same parameters via non-acupoints. Symptom questionnaires were completed daily. The electrogastrogram (EGG) and electrocardiogram (ECG) were recorded in the fasting state for 30 mins to assess gastric slow waves and autonomic functions, respectively, before and after the 3-day treatment.

RESULTS

1) In the acute phase (<24 h), TEA showed no effects on any of GI symptoms, compared with sham-TEA. 2) In the delayed phase (>24 h), TEA, compared with sham-TEA, decreased the percentage of patients who experienced nausea on POD3 (0% vs. 13.5%, p = 0.021), the nausea score on POD3 (p = 0.022), the anorexia score on POD2 (p = 0.040) and POD3 (p = 0.004), and the bloating score (POD1-3: p < 0.01). 3) In comparison with sham-TEA, TEA increased the number of spontaneous bowel movements (p = 0.001) and the Bristol score of the first stool (p = 0.014) and decreased the number of patients with the use of laxatives (p = 0.022). 4) Physiologically, the 3-day TEA but not sham-TEA increased the percentage of normal gastric slow waves (p < 0.001) and vagal activity (p = 0.006). The vagal activity was negatively correlated with the anorexia score (r = -0.267, p = 0.026). It was found that the sympathovagal ratio and tumor size>5 cm were independent risk factors predicting the occurrence of nausea in patients after TACE.

CONCLUSION

TEA improves major TACE-induced GI disturbances in the delayed phase, including nausea, bloating, impaired gastric pace-making activity, and constipation in patients with liver cancers via the autonomic pathway.

Ameliorating Effects and Autonomic Mechanisms of Transcutaneous Electrical Acustimulation in Patients With Gastroesophageal Reflux Disease

BACKGROUND/AIM

Gastric dysmotility is one of pathophysiologies of gastroesophageal reflux disease (GERD). The aim of this study was to investigate the effects of transcutaneous electrical acustimulation (TEA) on gastric accommodation and gastric slow waves, and evaluate possible mechanisms in patients with GERD.

METHODS

Thirty patients were studied in two randomized sessions of sham-TEA and TEA with the measurements of esophageal high-resolution manometry (HRM), gastric accommodation assessed by a nutrient-drinking test, electrogastrogram (EGG), electrocardiogram (ECG), and postprandial dyspeptic symptoms.

RESULTS

Compared with sham-TEA, TEA improved nutrient drinking-induced fullness (42.0 ± 3.3 vs. 31.0 ± 3.5, P = 0.003) at 10 min after the drink, and belching right after the drink (22.0 ± 4.6 vs. 11.7 ± 3.1, P = 0.012) and at 10 min (16.0 ± 3.8 vs. 3.0 ± 1.5, P = 0.002) after the drink. TEA also improved gastric accommodation (954 ± 37 mL vs. 857 ± 47 mL, P = 0.001) and normalized maximal drink-induced impairment in gastric slow waves. Concurrently, TEA enhanced vagal activity assessed from spectral analysis of heart rate variability in the postprandial state (0.42 ± 0.03 vs. 0.49 ± 0.04, P = 0.039). The vagal activity was positively correlated with the percentage of normal slow waves (r = 0.528; P = 0.003) and negatively correlated with the regurgitation score (r = -0.408, P = 0.025).

CONCLUSIONS

Acute TEA increases gastric accommodation, improves gastric slow waves, and reduces postprandial fullness and belching, possibly mediated via the vagal mechanisms.

Ameliorating Effects of Transcutaneous Electrical Acustimulation Combined With Deep Breathing Training on Refractory Gastroesophageal Reflux Disease Mediated via the Autonomic Pathway

AIMS

To investigate the effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) combined with deep breathing training (DBT) on refractory gastroesophageal reflux disease (rGERD).

METHODS

Twenty-one patients with rGERD were recruited and randomly assigned to receive either only esomeprazole (ESO, 20 mg bid) (group A, n = 7), TEA + DBT + ESO (group B, n = 7), or sham-TEA + DBT + ESO (group C, n = 7) in a four-week study. The reflux diagnostic questionnaire (RDQ) score and heart rate variability (HRV) were recorded and evaluated at baseline and at the end of each treatment. Blood samples were collected for the measurement of serum acetylcholine (Ach) and nitric oxide (NO). Esophageal manometry and 24-hour pH monitoring were performed before and after the treatment.

RESULTS

After treatment, 1) the participants in group B had significantly lower scores of RDQ and DeMeester and increased lower esophageal sphincter pressure (LESP) than those in group C (all p < 0.05), suggesting the role of TEA; 2) low frequency band (LF)/(LF + HF) ratio in groups B and C was decreased, compared with group A (p = 0.010, p = 0.042, respectively); high frequency band (HF)/(LF + HF) ratio in B and C groups was significantly increased, compared with group A (p = 0.010, p = 0.042, respectively); 3) The serum Ach in groups B and C was significantly higher than group A (p = 0.022, p = 0.046, respectively); the serum NO in groups B and C was significantly lower than group A (p = 0.010, p = 0.027, respectively).

CONCLUSIONS

TEA combined with the DBT can effectively improve the reflux symptoms in rGERD patients by increasing LESP and reducing gastroesophageal reflux, which may be mediated via the autonomic and enteric mechanisms.

Review article: treatment options for functional dyspepsia

BACKGROUND

Functional dyspepsia, consisting of epigastric pain syndrome and postprandial distress syndrome, is a prevalent functional gastrointestinal disorder. To date, only limited treatment options are available and conflicting results in terms of efficacy have been reported. Consequently, nonpharmacological treatment options are increasingly being explored for functional dyspepsia.

AIM

To provide an overview of current pharmacological and nonpharmacological treatment options for functional dyspepsia.

METHODS

A literature search was conducted on Pubmed and other sources to identify relevant studies.

RESULTS

Acid suppressive therapy reduced symptoms in 30%-70% of the patients, with higher benefit in epigastric pain syndrome and superior effectiveness for proton pump inhibitors compared to H₂ -antagonists. Prokinetic agents, primarily used to treat postprandial distress syndrome, showed variable efficiency: 59%-81% responder rate for dopamine receptor antagonists, 32%-91% for serotonin-4-receptor agonists and 31%-80% for muscarinic receptor antagonists. H Pylori eradication, recommended in infected patients, was effective in 24%-82%. Refractory symptoms are addressed with neuromodulators. However, their efficacy in functional dyspepsia remains incompletely elucidated, available data showing symptom reduction in 27%-71% of the patients. Regarding herbal agents, peppermint oil reduced symptoms in 66%-91%, rikkunshito in 29%-34% and iberogast in 20%-95%. Lastly, acupuncture, cognitive behavioural therapy and hypnotherapy may help to provide symptom control, but research on their efficacy remains sparse.

CONCLUSIONS

None of the available therapies is effective in the majority of patients without being associated with major side effects. Developing new treatment options is challenging due to the heterogeneity of functional dyspepsia, the lack of readily identified target mechanisms and the poor association between pathophysiological disturbances and symptoms.

Transcutaneous electrical acustimulation synchronized with inspiration improves gastric accommodation impaired by cold stress in healthy subjects

BACKGROUND

The aim of this study was to investigate whether transcutaneous electrical acustimulation (TEA) synchronized with inspiration (STEA), a method known to enhance vagal activity, was more effective than TEA in improving cold stress-induced impairment in gastric accommodation (GA) and dyspeptic symptoms in healthy subjects.

METHODS

Each of fifteen healthy subjects was studied in five randomized sessions: control (warm nutrient liquid), cold nutrient liquid (CNL), CNL+sham-TEA, CNL+TEA, and CNL+STEA. The subjects were requested to drink Ensure until reaching maximum satiety. STEA was performed using the same parameters as TEA but asking the subjects to breathe in when they sensed each stimulation train. The electrogastrogram (EGG) and electrocardiogram (ECG) were recorded to assess gastric slow waves (GSW) and autonomic functions, respectively.

KEY RESULTS

GA was reduced with the CNL in comparison with the warm drink but increased with TEA and STEA; STEA was more potent than TEA in improving GA; STEA was more potent in improving GSW than TEA; STEA significantly increased vagal activity and decreased sympathetic activity compared with TEA.

CONCLUSIONS AND INFERENCES

TEA synchronized with inspiration is more potent than TEA in improving cold stress-induced impairment in GA and GSW and dyspeptic symptoms and might be a novel noninvasive therapy for treating stress-induced dysmotility and dyspeptic symptoms.

Ameliorating effects and mechanisms of chronic electroacupuncture at ST36 in a rodent model of dyspepsia induced by cisplatin

BACKGROUND

Chemotherapy-associated dyspepsia syndrome (CADS) is among the most intensive side effects and critical concerns for patients with cancer. To investigate the effects and mechanisms of chronic electroacupuncture (EA) at ST36 on chemotherapy-associated dyspeptic symptoms (CADS) in rats.

METHODS

Cisplatin (8 mg/kg, ip) was given once to establish CADS model. EA or sham-EA treatment was then performed one hour daily for 21 days.

KEY RESULTS

(a) EA treatment decreased kaolin intake within 24 hours (1.67 ± 0.23 g vs 2.36 ± 0.37 g in sham-EA, P < 0.05); EA increased food intake (9.43 ± 2.28 vs 4.32 ± 1.26 in sham-EA, P < 0.05) and cisplatin-induced reduction of body weight (426.38 ± 13.25 vs 407.92 ± 13.26 in sham-EA, P = 0.05). (b) The incidence of normal behavioral satiety sequence (53%) in EA group was greater than that in sham-EA (32%) group (X²  = 17.68, P < 0.01). (c) EA increased the percentage of normal gastric slow waves (82.6 ± 5.98 vs 22.8 ± 1.90 in sham-EA, P < 0.05). (d) EA normalized cisplatin delayed gastric emptying (71.3% ± 6.8% vs 44.6% ± 11.2% in control, P < 0.05). (e) EA decreased ratio of heart rate variability (0.30 ± 0.03 vs 0.56 ± 0.05 in sham-EA, P < 0.05). (f) EA decreased fasting ghrelin, glucagon-like peptide-1 and peptide YY (P < 0.01 vs sham-EA for all).

CONCLUSIONS AND INFERENCES

Chronic EA ameliorates dyspepsia symptom and improves gastric dysmotility induced by Cisplatin, mediated via the vagal and gastrointestinal hormonal mechanisms.

Electroacupuncture via chronically implanted electrodes improves gastric dysmotility mediated by autonomic-cholinergic mechanisms in a rodent model of functional dyspepsia

BACKGROUND

Electroacupuncture (EA) has been shown to be effective in reducing symptoms in patients with functional dyspepsia (FD). However, its mechanisms remain largely unknown. The aim of this study was to investigate mechanisms of the prokinetic effects of EA in a rodent model of FD.

METHODS

A FD model was established by neonatal treatment of iodoacetamide (IA). Eight weeks later, the rats were implanted with electrodes in the stomach for the measurement of gastric slow waves (GSW) and electrodes into acupoints ST36 for EA. Autonomic functions were assessed by the spectral analysis of heart rate variability.

KEY RESULTS

(i) The IA-treated rats ("FD" rats) showed increased dysrhythmia in both fasting and fed states (P < .01) as well as during rectal distention (P < .02). EA reduced the percentage of dysrhythmia (P < .05 for both fasting and fed) and normalized RD-induced impairment in GSW in "FD" rats. Atropine blocked the effect of EA on GSW. (ii) "FD" rats showed delayed gastric emptying (P = .001 vs control) that was accelerated with EA (P = .01, vs sham-EA). (iii) "FD" rats showed increased plasma norepinephrine (P = .006, vs control) that was suppressed with EA (P = .003) and reduced vagal activity that was improved with EA.

CONCLUSIONS AND INFERENCES

Gastric motility (GSW and GE) is impaired in rats treated with IA, possibly attributed to impaired autonomic functions. EA improves GSW and accelerates GE mediated via the autonomic and cholinergic mechanisms.

Efficacy of needleless transcutaneous electroacupuncture in synchronization with breathing for symptomatic idiopathic gastroparesis: A blinded and controlled acute treatment trial

BACKGROUND

Needleless transcutaneous electroacupuncture (TEA) improves nausea and myoelectrical activity in diabetic gastroparesis (GP). Synchronized TEA (STEA), which combines synchronized breathing with TEA, is more potent than TEA in enhancing vagal activity in healthy subjects.

AIMS

To investigate whether STEA improves symptoms, electrogastrogram (EGG) and vagal activity in idiopathic gastroparesis (IGP).

METHODS

Eighteen IGP subjects underwent 2 randomized visits (sham at non-acupoints or real STEA at acupoints) consisted of a 30-minute baseline, an Ensure challenge to provoke nausea, followed by 60-minute treatment with sham or real STEA, and 15-minute observation period. Severity of nausea, EGG, and vagal activity (based on electrocardiogram and serum Pancreatic Polypeptide, PP) were recorded.

RESULTS

In sham or STEA, the nausea scores of 2.7 ± 0.5 and 1.9 ± 0.5 at fasting baseline, respectively, increased to 5.9 ± 0.4 and 5.8 ± 0.3 during Ensure test (P < .05, vs baseline), subsequently reduced to 3.4 ± 0.6 with sham or 3.6 ± 0.6 with STEA, respectively (P < .05, vs Ensure period). Experiments with sham and STEA started with similar % of normal waves on EGG (66.4 ± 3.9 and 61.8 ± 3.0, respectively); decreased to 63. 5 ± 4.1 and 58.2 ± 2.8 during the Ensure test. After STEA, there was ~24% increase in % of normal waves, significantly different from the sham (6.0%) (P < .01). In sham or STEA, vagal activity was identical at baseline and after the Ensure. STEA induced a 3-fold increase in vagal activity compared with sham (P < .01). Ensure increased serum PP levels, and both treatments decreased the PP CONCLUSIONS: In IGP, STEA is not superior to Sham in decreasing nausea, but is more effective in improving gastric dysrhythmia.

Needleless Transcutaneous Electrical Acustimulation: A Pilot Study Evaluating Improvement in Post-Operative Recovery

BACKGROUND

Functional gastrointestinal disturbance occurs after abdominal surgeries and could last for an extended period of time in some cases. This study was designed (1) to evaluate the effects of needleless transcutaneous electrical acustimulation (TEA) on postoperative recovery, and (2) to investigate the mechanisms involving autonomic function in postoperative patients after removal of gastrointestinal cancers.

METHODS

Forty-two patients (33 male, age: 69.5 ± 1.5 years) scheduled for abdominal surgical removal of gastrointestinal cancers were randomized to TEA (n = 21) and sham-TEA (n = 21). TEA was performed via acupoints ST36 and PC6 1 h twice daily from the postoperative day (POD) 1 to day 3. Sham-TEA was performed at non-acupoints.

RESULTS

(1) TEA improved major postoperative symptoms by about 30%, including a reduction in time to defecation by 31.7% (P < 0.01 vs. sham-TEA), time to first flatus by 35.9% (P < 0.001), time to ambulation by 42.8% (P < 0.01), time to resuming diet by 26.5% (P < 0.01) and hospital stay by 30% (P < 0.05) as well as pain score by 50% (P < 0.01). (2) TEA significantly increased vagal activity (P < 0.001) and decreased sympathetic activity on POD 4 (P < 0.001) compared with POD 1 as well as the serum level of NE (P < 0.05). (3) The vagal activity, high frequency assessed from the spectral analysis of heart rate variability, was negatively correlated with time to resuming diet, whereas the sympathetic measurement, serum norepinephrine was positively correlated with time to resuming diet and time to flatus. (4) TEA but not sham-TEA decreased TNF-α by 17.4% from POD 1 to POD 4. (5) TEA was an independent predictor of a shorter hospital stay.

CONCLUSIONS

Needleless TEA improves major postoperative symptoms by enhancing vagal and suppressing sympathetic activities.

Transcutaneous electroacupuncture alleviates postoperative ileus after gastrectomy: A randomized clinical trial

AIM

To investigate the efficacy and safety of transcutaneous electroacupuncture (TEA) to alleviate postoperative ileus (POI) after gastrectomy.

METHODS

From April 2014 to February 2017, 63 gastric cancer patients were recruited from the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China. After gastrectomy, the patients were randomly allocated to the TEA (n = 33) or control (n = 30) group. The patients in the TEA group received 1 h TEA on Neiguan (ST36) and Zusanli (PC6) twice daily in the morning and afternoon until they passed flatus. The main outcomes were hours to the first flatus or bowel movement, time to nasogastric tube removal, time to liquid and semi-liquid diet, and hospital stay. The secondary outcomes included postoperative symptom assessment and complications.

RESULTS

Time to first flatus in the TEA group was significantly shorter than in the control group (73.19 ± 15.61 vs 82.82 ± 20.25 h, P = 0.038), especially for open gastrectomy (76.53 ± 14.29 vs 87.23 ± 20.75 h, P = 0.048). Bowel sounds on day 2 in the TEA group were significantly greater than in the control group (2.30 ± 2.61/min vs 1.05 ± 1.26/min, P = 0.017). Time to nasogastric tube removal in the TEA group was earlier than in the control group (4.22 ± 1.01 vs 4.97 ± 1.67 d, P = 0.049), as well as the time to liquid diet (5.0 ± 1.34 vs 5.83 ± 2.10 d, P = 0.039). Hospital stay in the TEA group was significantly shorter than in the control group (8.06 ± 1.75 vs 9.40 ± 3.09 d, P = 0.041). No significant differences in postoperative symptom assessment and complications were found between the groups. There was no severe adverse event related to TEA.

CONCLUSION

TEA accelerated bowel movements and alleviated POI after open gastrectomy and shortened hospital stay.

Functional dyspepsia and gastroparesis

PURPOSE OF REVIEW

This review summarizes recent progress in the epidemiology, pathophysiology and treatment of functional dyspepsia and gastroparesis.

RECENT FINDINGS

The definition of functional dyspepsia and its subgroups has been revised in the recent Rome IV consensus. In gastroparesis, the symptom pattern and its similarities and differences from functional dyspepsia have been a focus of recent research. In functional dyspepsia, pathophysiological research continued to evaluate gastric sensorimotor dysfunctions, but low-grade inflammatory changes and loss of mucosal integrity in the duodenum is a new topic of intense research. Treatment advances include new prokinetics such as acotiamide and the ghrelin receptor agonist relamorelin. The efficacy of tricyclic antidepressants was recently reviewed and mirtazapine is a new agent used in the treatment of functional dyspepsia and gastroparesis. In gastroparesis, research has focused on the role of macrophages in loss of interstitial cells of Cajal, and on the role of pyloric resistance as a target for therapy, using botulinum toxin injection and gastric per-endoscopic pyloric myotomy.

SUMMARY

The functional dyspepsia definition and subgrouping were updated in the Rome IV consensus. Research focuses on duodenal mucosal alterations in functional dyspepsia and pyloric resistance in gastroparesis. New treatments include novel prokinetics and pylorus-directed interventions.

Effect of Electroacupuncture on the NTS is modulated primarily by acupuncture point selection and stimulation frequency in normal rats

Background

The effect of electroacupuncture (EA) is affected by both the acupuncture point selection and the frequency of stimulation. However, little is known regarding acupuncture point and simulation frequency selection. Neuronal activation of the nucleus of the solitary tract (NTS) is one of the important targets of EA for modulating gastrointestinal function. This study investigated the effects of various combinations of EA frequencies and acupuncture points on NTS neurons.

Methods

Rats were randomly divided into normal, 2 Hz EA, 100 Hz EA and the alternate 2/100 Hz EA groups. Then rats in each group were randomly divided into the following two subgroups according to the acupuncture point: ST 36 group and ST 25 group. All the rats underwent electrode implantation surgery. Rats in all EA groups received one treatment with EA (a constant square wave at, 2 Hz,100 Hz or 2/100 Hz frequencies with intensities ranging from 1 to 2 mA), and NTS neuronal activation was recorded before and after EA treatment. Finally, to confirm the effect of EA on the NTS, minimal acupuncture was administered and its effect on NTS was detected.

Results

ST 36 stimulated with 2 Hz EA significantly increased the population of excited NTS neurons and spike frequency. However, ST 36 stimulated with 100 Hz or 2/100 Hz EA produced only a transient effect on the activity of NTS neurons and did not induce any effect on the spike frequency. Furthermore, the excitatory effect of 100 Hz or 2/100 Hz EA on NTS neurons in the ST 36 group was lower than 2 Hz EA at the same point. When applied to ST 25, 2 Hz EA had no significant excitatory effect on NTS neurons or spike frequency. However, 100 Hz EA or 2/100 Hz EA at ST 25 decreased both NTS neuronal excitability and spike frequency. By comparing the effects of different EA combinations, it was shown 2 Hz EA applied to ST 36 had the strongest excitatory effect on NTS neurons, while 100 Hz EA applied to ST 25 had the greatest inhibitory effect. Minimal acupuncture stimulation produced no effect on NTS neurons.

Conclusion

EA’s effects on NTS were mainly affected by the acupuncture point selection, but the frequency of EA also played a role. Different combinations of acupuncture points and frequency selection may lead to different EA effects on NTS neuronal excitability.

Electroacupuncture treatment partly promotes the recovery time of postoperative ileus by activating the vagus nerve but not regulating local inflammation

Postoperative ileus (POI) after abdominal surgery significantly lowers the life quality of patients and increase hospital costs. However, few treatment strategies have successfully shortened the duration of POI. Electroacupuncture (EA) is a modern way of administering acupuncture and widely used in various gastrointestinal (GI) diseases in the world. Here, we studied the effect of EA on POI and its underlying mechanisms. Intestinal manipulation resulted in significant delays of GI transit, colonic transit and gastric emptying. Surgery also up-regulated c-fos in nucleus of the solitary tract (NTS) and induced inflammation response in the small intestine. Further, operation and inhale anesthesia inhibited NTS neuron excitation duration for the whole observation time. EA administered at ST36 indeed shortened the recovery time of GI and colonic transit, and significantly increased the gastric emptying. EA also significantly activated the NTS neurons after operation. However, there was no anti-inflammation effect of EA during the whole experiment. Finally, atropine blocked the regulatory effect of EA on GI function, when it was injected after surgery, but not before surgery. Thus, the regulatory effect of EA on POI was mainly mediated by exciting NTS neurons to improve the GI tract transit function but not by activating cholinergic anti-inflammatory pathway.

Effects of Transcutaneous Electrical Acustimulation on Refractory Gastroesophageal Reflux Disease

Objective. To investigate effects and possible mechanisms of transcutaneous electrical acustimulation (TEA) performed by a wearable watch-size stimulator for refractory gastroesophageal reflux disease (RGERD). Methods. Twenty patients diagnosed as RGERD were enrolled in the study and randomly divided into four groups: esomeprazole group (Group A), esomeprazole combined with TEA group (Group B), esomeprazole combined with sham-TEA group (Group C), and esomeprazole combined with domperidone group (Group D). HRM and 24 h pH-impedance monitoring and GerdQ score were used to measure related indexes before and after treatment. Results. (1) TEA significantly increased LESP, compared with PPI treatment only or PPI plus sham-TEA. After pairwise comparison, LESP of Group B was increased more than Group A (P = 0.008) or Group C (P = 0.021). (2) PPI plus TEA decreased not only the number of acid reflux episodes but also the number of weak acid reflux episodes (P = 0.005). (3) Heartburn and reflux symptoms were improved more with PPI + TEA than with PPI treatment only or PPI plus sham-TEA (GerdQ scores, P = 0.001). Conclusion. TEA can improve symptoms in RGERD patients by increasing LESP and decreasing events of weak acid reflux and acid reflux; addition of TEA to esomeprazole significantly enhances the effect of TEA.