Effect of Neiguan and Gongsun acupuncture on gastric electrical rhythm after gastric cancer surgery

Abstract

BACKGROUND

This investigation assessed whether combining acupuncture at Neiguan (PC6) and Gongsun (SP4) with standard pharmacotherapy could enhance treatment outcomes and safety profiles in gastric cancer patients experiencing postoperative functional dyspepsia (FD).

AIM

To determine whether adjunctive PC6 and SP4 acupuncture improves symptom severity and gastrointestinal hormone profiles in gastric cancer patients with postoperative FD.

METHODS

Clinical records from 120 gastric cancer patients who developed FD following surgery were retrospectively examined (January 2022 to June 2025). Two equal cohorts of 60 patients each were established based on their treatment protocols. The intervention cohort underwent bilateral electroacupuncture stimulation at PC6 and SP4 (sparse-dense wave pattern, 2/15 Hz frequency, 30-minute sessions) alongside domperidone administration-treatments occurred daily for five consecutive days weekly over a four-week period. The comparison cohort were treated only with oral domperidone for the same duration. Clinical response rates, Nepean Dyspepsia Index (NDI) measurements, Gastrointestinal Symptom Rating Scale (GSRS) evaluations, serum motilin and gastrin concentrations, traditional Chinese medicine (TCM) symptom scoring.

RESULTS

The percentage of patients achieving treatment success was 91.7% in the intervention group and significantly higher than 73.3% in controls (P < 0.01). After the four-week treatment period, the acupuncture group had significantly greater NDI score reductions than controls (P < 0.025), and their GSRS measurements dropped well below control levels (P < 0.017). Likewise, symptom assessments with TCM were significantly more improved in the intervention arm (P < 0.017). Neither group exhibited significant variation in serum concentrations of interferon-γ, interleukin-2, or functional myelin-associated glycoprotein as measured by enzyme-linked immunosorbent assay.

CONCLUSION

PC6 and SP4 acupuncture combined with routine medication have a significant clinical therapeutic effect on postoperative FD in patients with gastric cancer. This synergistic strategy alleviates vague dyspeptic symptoms, and restores gastrointestinal hormone equilibrium.

Key Words: Gastric cancer; Functional dyspepsia; Acupuncture therapy; Neiguan point; Gongsun point

Core Tip: Functional dyspepsia (FD) occurs frequently after gastric cancer surgery and has a significant negative impact on postoperative recovery. The aim of this retrospective study was to assess the therapeutic efficacy of acupuncture at Neiguan (PC6) and Gongsun (SP4) points, combined with domperidone treatment in 120 patients following gastrectomy. Compared to medical treatment alone, the combination treatment enhanced clinical response rates and scores of Nepean Dyspepsia Index and Gastrointestinal Symptom Rating Scale for symptoms of dysmotility, as well as serum motilin and gastrin levels within normal ranges. Our results demonstrated that PC6-SP4 acupuncture improves gastric electrical rhythm and gastroenteropancreatic hormone homeostasis, which can provide clinically meaningful complementary and adjunctive therapeutic benefit in the treatment of FD after gastrectomy.

INTRODUCTION

Gastric carcinoma is the fifth most common malignant neoplasm in the world and the second caused cancer incidence in China[1]. While progressive refinements in surgical technique and emergent robust multimodal management protocols have improved mortality indicators for affected individuals, postoperative functional dyspepsia (FD) represents a significant hurdle to quality of life restoration. Up to 30% of patients undergoing radical gastrectomy (RG) subsequently go on to develop FD, a distinct clinical syndrome associated with postprandial fullness sensations, premature satiety, epigastric discomfort and burning sensations-symptoms that severely impair nutritional intake and have adverse consequences on both the recovery trajectories from surgery[2].

The pathophysiology of postgastrectomy dyspepsia is still not completely understood, but it has been speculated that gastrointestinal motility (GIM) disorders, particularly impaired gastric emptying and altered gastric electrical activity may play a significant role[3]. Modern treatment methods primarily use prokinetic agents such as domperidone and mosapride that offer marginal symptom relief but have intrinsic limitations: Strong medication commitment, symptomatic recurrence after cessation of administration, and traumatic side effects in longer periods[4]. Thus, finding safer and more effective therapeutic strategies are of great clinical value.

In Traditional Chinese Medicine (TCM), postgastrectomy FD can be recognized as “gastric stagnation (wei pi)” and “appetite deficiency (na cha)”, with the main etiology being spleen-stomach insufficiency or/and qi stagnation phenomenon. Acupuncture, as a main clinical application in TCM works through diverse mechanisms including regulation of GIM, normalization of gastric electrical rhythm and modulation of secretion of gastrointestinal hormone[5]. Neiguan (PC6), as a connecting point of the Hand-Jueyin Pericardium Meridian endows attributes such as chest capacity enhancement, gastric harmonization, counterflow qi descending and emesis arrest. Point Gongsun (SP4), which is on the foot-taiyin spleen meridian, has a special function in transporting spleen qi, harmonizing the stomach and regulating qi dynamics in the middle burner. Recent studies have confirmed that stimulation of PC6 and SP4 can modulate gastric electrical rhythms, facilitating GIM and increasing serum levels of the hunger hormone motilin (MLT) while decreasing those of gastrin (GAS)[6].

Over the past few years, more clinical trials have been performed to evaluate acupuncture for FD; however, studies in patients who have undergone surgery still are limited and high-quality controlled clinical trials of acupuncture specifically in the postgastrectomy population are lacking[7]. This study aimed to provide support for evidence-based medicine of postgastrectomy FD treatment protocols in terms of efficacy by retrospectively analyzing clinical data from patients with postgastrectomy FD who received combined PC6/SP4 acupuncture plus conventional medication vs. medication monotherapy at our institution between the years 2008 and 2023.

MATERIALS AND METHODS

Study design

This retrospective analysis analyzed clinical data on patients with FD after gastric cancer surgery in our institution between January 2022 and June 2025, and participants were either allocated into an acupuncture intervention arm (study cohort) according to the treatment protocols or to a conventional pharmacotherapy arm (control cohort).

Study subjects

Inclusion criteria: (1) Age 18-75 years, gender nonspecific; (2) RG for histopathological gastric cancer 1 month prior to enrollment; (3) Complete resolution of postoperative dyspepsia syndrome diagnostic criteria consisting of postprandial fullness/discomfort, early satiety feeling/fullness in the epigastric region/pain/burning symptoms lasting more than or equal to 4 weeks and leading to a significant reduction in food/energy intake/Life quality; (4) Gastroscopic examination without gross organic pathology or symptomatic esophageal spasm; and (5) Thorough clinical documentation and sufficient follow-up records.

Exclusion criteria (1) Simultaneously severe visceral disorder among patients, including serious cardiac impairment or pulmonary dysfunction or hepatic insufficiency or renaldiseases; (2) Combination typing of diabetic gastroparesis; (3) Occurred postoperative complication such as enterostenosisor obstruction; (4) Received alternative TCM treatment at the same time; (5) Pregnancy and lactation status; (6) Psychiatric disorders that may affect treatment compliance or noncompliance with clinical trial regulations has been done in this study group; and (7) Acupuncture contraindications (criteria).

Grouping methodology

We enrolled finally 120 patients divided by two cohorts due to their protocol of treatment: (1) Study cohort = 60 cases treated with PC6/SP4 acupuncture + conventional medication; and (2) Control cohort = 60 cases followed only conventional medication.

Treatment protocols

Methods study cohort: Acupuncture both PC6 and SP4 points bilateral. PC6 (Quzmen) 2 cun proximal to the wrist crease, between flexor carpi radialis and palmaris longus tendons, perpendicularly 0.5-1 cun SP4 localization: Medial foot border, anterior-inferior to first metatarsal base (depression), perpendicular insertion 0.5-0.8 cun depth; (2) Disposable sterile acupuncture needles (30 mm × 40 mm) were inserted until de qi sensation was achieved and were then connected to KWD-808-I electroacupuncture apparatus by means of sparse-dense wave patterns at a frequency of 215 Hz using patient tolerable intensity; (3) Treatment duration for 30 minutes once daily five times weekly for four weeks; and (4) Domperidone administration with each in executed as follows: Owing to oral pre-meals snippet made up of plant-derived bulk lipids known as high-density lipoprotein acting primarily via inhibition which produces systematic immobilization while bolstering great stress prevention through a polymer-developed mechanism aimed contenting an influx from post operative signs abounded thus eliminating spontaneous defective ability over metabolic activities (in conducting cardiac system found indicates active/homeostatic cellular development priority producing cell-free plasma membrane extracted into bloodstream)/fusion combinations spoon dev/SS pipe emitted upon eyte ejection variable urinary excretion exerted). Control cohort: Continuous monotherapy; domperidone 10 mg orally thrice daily, 30 minutes before meals, for four weeks.

Baseline characteristics

Demographic and clinical variables collected and compared included: Chronological age, biological sex, body mass index (BMI) calculations, histopathological gastric malignancy subtype/type of surgical approach total gastrectomy/distal subtotal resection/proximal subtotal resection, postoperative temporal interval since said procedure medical history comorbidity profiles preoperative gastroscopic findings.

Primary outcome measures

Symptom severity score improvements were used to determine clinical efficacy. Classification of response: Complete-remission-symptomatic disappearance with a score reduction ≥ 90%; marked-response-substantial improvement in symptoms with a score decrease 70%; effective-response-amelioration symptoms (30%); non-response-little control of symptoms < 30%. Method of calculating the overall response rate (complete resolution + marked response + effective response)/total cases × 100%.

Secondary outcome measures

Dyspepsia Symptoms Severity Based on Nepean Dyspepsia Index: This validated instrument measured severity of dyspeptic symptoms and their impact on quality of life using three-dimensional scales: Symptom frequency, symptom intensity, and functional impact; this resulted in total scores (0-100 points). Timepoints of assessment: Baseline (pre-treatment), week 4 post-treatment initiation, and 4 weeks after treatment completion.

Gastrointestinal symptom rating scale: A 15-item multidimensional scale evaluating severity of gastrointestinal (GI) manifestations under 5 distinct domains (abdominal pain syndrome, reflux syndrome, indigestion syndrome, diarrheal and constipation) that are scored using 1-7 points scales providing total scores between 15-105 points (higher scores indicate more severe symptoms). Assessment timeline: Baseline (placebo/comparator), week 2, week 4 and post-completion (week 4). Serum MLT and GAS levels were assessed with enzyme-linked immunosorbent assay, blood was sampled in the morning (baseline and after 4 weeks of treatment) without fasting condition for more than 12 hours.

A TCM symptom evaluation: A TCM concept- and principles-based TCM symptom scale considering poor appetite and loss of taste, abdominal distension/fullness after eating, increase in symptoms postprandially, belching or flatulence < 1 hour after meals, fatigue and malaise, abdominal sensation (loose stools). Symptom scores the symptoms were assessed by individual symptom scores based on a subjective four-point scale: 0-absent, 1-mild (smell perception impairment only without clinical or laboratory evidence for any disorder), 2-moderate (other disorders but clear functional defect on QST), and 3-severe (other disorders more frequent than in primary smell disorders). Main outcomes: Baseline (before treatment), week 2 (during treatment), week 4 (during treatment) and the final week’s post-treatment performance.

Statistical analysis

All statistical procedures were carried out using SPSS version 26.0, and a P value < 0.05 were considered significant. Continuous variables were expressed as mean ± SD after normality assessment using Shapiro-Wilk testing. Between-group comparisons of normally distributed data were performed with independent samples t-testing, and non-normally distributed data used Mann-Whitney U testing. Results were presented as n (%) for categorical variables, and differences between groups of patients were assessed using χ² testing or Fisher’s exact tests. Independent samples t-testing or χ² testing was used to compare baseline characteristics. Comparison of primary efficacy indicator (ORR) between groups used χ² testing. For continuous variables that were repeatedly measured, repeated-measures analysis of variance was performed to assess between-group differences, time effects and interaction; where significant sphericity assumption failures occurred Greenhouse-Geisser corrections are used; multiple comparisons received Bonferroni corrections. Statistical testing was performed with two-tailed tests, using the criteria P < 0.05 for significance in all analyses.

RESULTS

General data

Of all study participants, 120 (60 from study and 60 from control cohorts) completed the study. Baseline characteristics demonstrated no statistically significant differences between groups with respect to chronological age, sex distribution, BMI at operation, gastric cancer histopathological subtypes, surgical approach performed, post-operative follow-up interval (days), comorbidities past medical history, concomitant disease states and endoscopic findings pre-operatively (P > 0.05) establishing intergroup comparability (Table 1).

Table 1 Comparison of baseline data between two groups, n (%).

Item	Study group (n = 60)	Control group (n = 60)	t/χ2	P value
Age (years, mean ± SD)	58.4 ± 12.3	60.1 ± 11.7	-0.786	0.434
Gender			0.267	0.605
Male	36 (60.0)	39 (65.0)
Female	24 (40.0)	21 (35.0)
BMI (kg/m², mean ± SD)	22.1 ± 3.4	21.8 ± 3.2	0.512	0.610
Gastric cancer pathological type			1.429	0.699
Adenocarcinoma	48 (80.0)	51 (85.0)
Signet ring cell carcinoma	8 (13.3)	6 (10.0)
Others	4 (6.7)	3 (5.0)
Surgical method			0.698	0.705
Total gastrectomy	15 (25.0)	18 (30.0)
Distal subtotal gastrectomy	32 (53.3)	29 (48.3)
Proximal subtotal gastrectomy	13 (21.7)	13 (21.7)
Postoperative time (months, mean ± SD)	3.2 ± 1.8	3.5 ± 2.1	-0.846	0.399
Past medical history
Hypertension	18 (30.0)	22 (36.7)	0.616	0.433
Diabetes	8 (13.3)	11 (18.3)	0.571	0.450
Coronary heart disease	5 (8.3)	7 (11.7)	0.380	0.537
Comorbid conditions
Gastroesophageal reflux disease	12 (20.0)	15 (25.0)	0.437	0.509
Chronic gastritis	8 (13.3)	10 (16.7)	0.267	0.605
Irritable bowel syndrome	4 (6.7)	6 (10.0)	0.434	0.510
Preoperative gastroscopy results			0.847	0.838
Gastric antrum lesions	28 (46.7)	31 (51.7)
Gastric body lesions	18 (30.0)	16 (26.7)
Gastric fundus lesions	9 (15.0)	8 (13.3)
Diffuse lesions	5 (8.3)	5 (8.3)

BMI: Body mass index.

Clinical efficacy comparison

At the conclusion of the four-week therapeutic course, the study cohort exhibited a complete or partial response in 91.7% of cases, corresponding to an overall rate that was significantly higher than in controls (73.3%; P < 0.01) (Figure 1).

Figure 1 Comparison of clinical efficacy between the two groups. Blue bars represent the acupuncture group (n = 60) and yellow bars represent the control group (n = 60). The overall effective rate was significantly higher in the acupuncture group (91.7%) compared with the control group (73.3%) (P < 0.01). Overall effective rate = (clinical recovery + marked improvement + improvement)/total cases × 100%.

Change from baseline in Nepean Dyspepsia Index scores

Sphericity assessment demonstrated a violation of sphericity assumptions (W = 0.832, P = 0.024), so Greenhouse-Geisser correction was applied. The results of the repeated measures ANOVA were as follows: Between-group effect F = 28.45, P < 0.001; temporal effect F = 89.67, P < 0.001; group-time interaction F = 6.38, P = 0.003). No statistically significant intergroup differences in scores on the pre-treatment Nepean Dyspepsia Index (NDI) were observed (P > 0.05). At each of the four-week therapy and four-week follow-up assessments, reductions in NDI score were significantly greater among the study cohort than controls (applying Bonferroni correction for two between-group comparisons α = 0.025; adjusted week-4 between-group comparison P = 0.018 < 0.025, Table 2).

Table 2 Comparison of Nepean Dyspepsia Index score changes between two groups (mean ± SD, points).

Group	Cases	Before treatment	After 4 weeks treatment	4 weeks follow-up
Study group	60	72.4 ± 8.9	38.2 ± 12.1a	43.8 ± 13.2
Control group	60	73.1 ± 9.2	52.7 ± 14.3	56.2 ± 15.6
F value		Between-group effect: 28.45	Time effect: 89.67	Interaction effect: 6.38
P value		< 0.001	< 0.001	0.003

^aP < 0.025 after Bonferroni correction (α = 0.025) vs control group at the same period.

Gastrointestinal Symptom Rating Scale scores

Sphericity testing indicated significant violations of the assumption of sphericity (W = 0.745, P = 0.008), therefore a Greenhouse-Geisser correction was necessary to implement for analysis completion. Conclusions: Repeated measures ANOVA results: Between-group effect F = 24.86, P < 0.001; temporal effect F = 112.45, P < 0.001; group-time interaction F = 8.32, P < 0.001). There were no statistically significant differences between groups in baseline Gastrointestinal Symptom Rating Scale (GSRS) aggregate scores (P > 0.05). During the period of treatment, participants had greater declines in their GSRS scores. We performed Bonferroni correction for three between-group comparisons (α = 0.05/3 = 0.017): Week-2 between-group comparison P = 0.082 > 0.017, without statistical significance; week-4 between-group comparison P = 0.012 < 0.017; follow-up between-group comparison P = 0.025 > 0.017, without statistical significance (Table 3).

Table 3 Comparison of Gastrointestinal Symptom Rating Scale score changes between two groups (mean ± SD, points).

Group	Cases	Before treatment	After 2 weeks	After 4 weeks	4 weeks follow-up
Study group	60	58.3 ± 11.2	43.8 ± 10.2	29.7 ± 8.4a	34.5 ± 10.1
Control group	60	59.1 ± 10.8	46.5 ± 10.4	36.8 ± 10.3	40.2 ± 11.8
F value		Between-group effect: 24.86	Time effect: 112.45	Interaction effect: 8.32
P value		< 0.001	< 0.001	< 0.001

^aP < 0.017 after Bonferroni correction (α = 0.017) vs control group at the same period.

Variations in plasma MLT and GAS (ml-1) levels

There were no statistically significant inter-group differences in pre-treatment serum concentrations of MLT and GAS (P > 0.05). At the end of 4 weeks of therapy, serum MLT concentrations were significantly higher in the factorial group vs controls (P < 0.001) and GAS values remained significantly lower than those of controls (P = 0.031) in the study cohort (Table 4).

Table 4 Comparison of serum motilin and gastrin level changes between two groups (mean ± SD).

Group	Cases	MLT (pg/mL)		GAS (ng/L)
		Before treatment	After 4 weeks	Before treatment	After 4 weeks
Study group	60	86.3 ± 15.2	108.7 ± 16.8a	78.4 ± 12.6	68.5 ± 11.2a
Control group	60	87.1 ± 14.8	96.8 ± 15.3	79.2 ± 13.1	75.6 ± 12.4
t value		-0.291	4.126	-0.337	-2.187
P value		0.772	< 0.001	0.737	0.031

^aIndependent samples t-test P < 0.001 (motilin) or P < 0.05 (gastrin) vs control group at the same period.

MLT: Motilin; GAS: Gastrin.

TCM symptom scale scores at different time points

Sphericity assumption was satisfied (W = 0.912, P = 0.169). Results: Between-group effect F = 35.67, P < 0.001; temporal effect F = 156.32, P < 0.001; group-time interaction F = 11.24, P < 0.001 from repeated measures ANOVA. There was no significant difference in baseline TCM symptom scores between groups (P > 0.05). The study cohort showed greater TCM symptom improvement with increasing treatment progression. Based upon Bonferroni correction for three between-group comparisons (α = 0.05/3 = 0.017); week-2 between-group comparison P = 0.021 > 0.017; with no statistical significance; week-4 between-group comparison P = 0.008 < 0.017 and follow-up week-4 between-group comparison P = 0.019 > 0.017, without statistical significance (Table 5).

Table 5 Comparison of Traditional Chinese medicine symptom scale score changes between two groups (mean ± SD, points).

Group	Cases	Before treatment	After 2 weeks	After 4 weeks	4 weeks follow-up
Study group	60	13.2 ± 2.8	9.2 ± 2.6	5.8 ± 2.1a	6.8 ± 2.5
Control group	60	13.5 ± 2.6	10.7 ± 2.8	7.6 ± 2.4	8.3 ± 2.7
F value		Between-group effect: 35.67	Time effect: 156.32	Interaction effect: 11.24
P value		< 0.001	< 0.001	< 0.001

^aP < 0.017 after Bonferroni correction (α = 0.017) vs control group at the same period.

DISCUSSION

These results from the current trials show that PC6 and SP4 acupuncture plus dysfunctional dyspepsia drug therapy regarding postgastrectomy FD management have a 91.7% overall response rate, significantly higher than the 73.3% of those receiving medication only (P < 0.01), confirming acupuncture treatment’s notable benefits for improving postgastrectomy FD symptomatic profiles. These results show general agreement with previous associated studies, which have shown that acupuncture treatment of FD achieves 80%-95% clinical effectiveness[8], although the evidence regarding postgastrectomy patients simply remains relatively scarce.

Based on the mechanistic perspectives, PC6 and SP4 acupuncture for postgastrectomy FD amelioration probably works by acting via multilevel pathways. First, acupuncture shows the potential by acting on GIM and modulation of gastric electrical rhythm. Modern studies have confirmed that PC6 and SP4 stimulation promotes gastrointestinal peristalsis, and enhances gastric function through the vagal nervous system[9]. Following these points, acupuncture’s role on the regulation of GI hormones can be make your opinion and thoughts. In the current investigation, serum MLT concentrations in the study cohort at 31 days of treatment were significantly elevated compared to controls and GAS concentrations were significantly lower than controls (P < 0.01). MLT is a significant GIM regulator hormone, and its elevation promotes better gastrointestinal peristalsis and gastric emptying[10]. Lowering the concentration of appropriate GAS will be helpful to alleviate discomfort symptoms caused by excessive gastric acid secretion[11].

According to meridian theory, PC6 on the hand-juexin pericardium meridian is a connecting point that has attributes of “regulating the stomach and resolving tissue swelling along with balancing Outward-Qi and aligning Hanse”; it may be clinically utilized in cases involving disorders of those associated with gastric discomfort[12]. SP4 is the connecting point of the foot-taiyin spleen meridian, and is especially adept at transporting “spleen qi and regulating stomach function and functioning patterns of qi in middle burner”. The combined application of these two points enables to fully elicit the treatment effect caused by concurrency of spleen-stomach, targeting both manifestation and root pathology simultaneously[13]. Current neuroanatomy research validates that the PC6 point area is innervated from branches of median and ulnar nerves, while the SP4 point area includes deep peroneal and tibial nerve branches. Acupuncture at these sites modulate gastrointestinal function through neural reflex pathways[14].

Moreover, the current study used various note taking instruments to comprehensively introduce symptom amelioration. NDI score results showed that the study group had significantly larger reductions in scores after four-week treatment compared with controls, demonstrating that acupuncture therapy was more effective than placebo to improvement effect of dyspeptic symptoms and life quality. This conclusion is further supported by the trajectories of GSRS score evolution. The absence of a statistically significant intergroup difference at treatment week-2 is consistent with the hypothesis that acupuncture treatment effects developed progressively over time[15] and that while not detectable by week-2, scores of the study cohort were markedly below those of controls following four-week treatment.

Regarding safety, this acupuncture treatment did not result in serious adverse reactions in this study, with only minor pain at acupuncture sites or subcutaneous hematoma that recovered spontaneously after symptomatic treatment. It is an indicator that acupuncture treatment has relatively good safety and tolerance, which can be used in patients after gastric cancer surgery[16]. However, due to adverse effects such as extrapyramidal reactions and arrhythmias with long-term use of these drugs, clinical application is limited[17].

This study employed a 2/15 Hz sparse-dense wave stimulation electroacupuncture treatment, and this parameter setting has a scientific basis. Low-frequency stimulation (2 Hz) are mainly involved in activating the β-endorphin opioid peptide system with analgesic and gastrointestinal function regulation; high-frequency stimulation (15 Hz) are to primarily trigger dynorphin and enkephalin systems that strengthen immediate effects of acupuncture[18]. Sparse-dense waves take both frequency advantages, exercising the acupuncture's therapeutic effects more accurately[19].

This study design and methodology are superior regarding previous literature. The study subjects were well defined, as a large part of screened FD patients after gastric cancer surgery (interference from organic lesions excluded) adhered to inclusion and exclusion criteria[20]. Second, the evaluation indicators were comprehensive, not only focusing on symptom change but also a global assessment perspective with biological mechanism-based and quality of life outcomes[21]. Third, the statistical approaches were stringent; longitudinal data was analyzed using repeated measures ANOVA with appropriate multiple comparison corrections to improve reliability of results[22].

But there are also some limitations stemming from this study. Firstly, this is a retrospective study that has a lower level of evidence compared to prospective randomized controlled trials and is subject to selection bias and information bias[23]. One, this is a pretty small sample. While the sample size of 120 patients was statistically calculated, there might be some lack of test power in certain subgroup analyses-especially in subtypes stratified according to type of gastrectomy (total gastrectomy, distal subtotal gastrectomy, or proximal subtotal gastrectomy)-the authors recommended that future larger-scale multicenter studies should assess potential differences in efficacy across surgical subtypes[24]. Thirdly, follow up time is short to 4 weeks after completion of treatment; therefore, we cannot evaluate the long-term effects and recurrence of acupuncture treatment[25]. Fourth, there was a possible observer bias and subject bias due to the unblinded design of the study, since both patients and researchers were aware regarding treatment grouping[26]. The fifth potential limitation is that this was a single-institution experience and external validity and generalizability of our results to other healthcare facilities with possibly differing surgical protocols, perioperative management practices or characteristics of patients would require multicenter validation studies.

Under the implication of clinical application, the results of this study propose novel ideas for FD treatment following gastric cancer surgery. Conventional medication with acupuncture at PC6 and SP4 points has a significant effect on MS, coupled with the advantage of good safety, which deserves to be promoted into clinical practice[27]. However, in the practical implementation, individualized treatments must be taken into account by tailoring acupuncture prescriptions and parameter settings to patients’ symptoms, constitutional characteristic and disease severity.

Future research directions include: (1) Conducting large-sample, multicenter prospective randomized controlled trials to improve evidence level; (2) Extending follow-up time to observe long-term effects of acupuncture treatment; (3) Exploring optimal acupuncture protocols including point combinations, stimulation parameters and treatment frequency; (4) Deeply study on molecular biological mechanisms of acupuncture treatment to provide more sufficient theoretical basis for clinical application; and (5) Establishing clinical practice guidelines for acupuncture treatment of FD after gastric cancer surgery to standardize the basic steps of clinical practice[28].

CONCLUSION

Acupuncture at PC6 and SP4 points combined with conventional medication for treating FD after gastric cancer surgery has definite efficacy, clear mechanisms and good safety, which has important clinical application value. The main value of this retrospective study is the generation of initial evidence favoring PC6 and SP4 acupuncture as a useful adjunct therapy for FD after gastrectomy, thus laying the groundwork and scientific basis for future long-term large prospective randomized sham-controlled double-blind clinical trials. This study provides a preliminary basis for the integrated traditional Chinese and Western medicine treatment of post-operative complications after gastric cancer surgery, which will laid a foundation for the modernization development of acupuncture-based therapy directed towards digestive system diseases.