Functional recovery after abdominal surgery and the emerging role of acupuncture

Abstract

Gastrointestinal dysfunction is a common clinical problem following abdominal surgery. The delayed recovery of bowel function, along with abdominal distension, nausea, and inflammatory responses, prolongs the hospital stay and increases healthcare costs despite the global application of enhanced recovery after surgery (ERAS) programs. Despite the regular use of pharmacologic prokinetics and other supportive measures, rapid and sustained functional recovery remains elusive in many patients. A recent study demonstrated that patients with postoperative gastrointestinal dysfunction experienced improved recovery of gastrointestinal function and reduced inflammation when treated with acupuncture and moxibustion in addition to Western medicine treatment. According to their findings, complementary methods may offer benefit in addition to standard pharmacological management. This study also challenges the conventional definition and assessment of postoperative recovery. As surgical care focuses on restoring function instead of just avoiding complications, the systematic appraisal of adjunctive non-pharmacological interventions is warranted in ERAS pathways. Future research should focus on standardized recovery metrics, mechanistic clarification, and integration into multidisciplinary perioperative care models. This will help determine whether complementary therapies can meaningfully improve patient-centered outcomes after abdominal surgery.

Key Words: Enhanced recovery after surgery; Acupuncture; Electroacupuncture; Transcutaneous electrical acupoint stimulation; Postoperative ileus; Gastrointestinal recovery; Non-pharmacological interventions

Core Tip: Although improving with enhanced recovery after surgery (ERAS) protocols, postoperative gastrointestinal dysfunction, especially after abdominal surgery, remains a significant impediment to rapid recovery. Emerging evidence suggests that acupuncture and related non-pharmacological interventions, especially electroacupuncture and transcutaneous electrical acupoint stimulation, may facilitate gastrointestinal functional recovery, alleviate postoperative ileus, and enhance patient-related outcomes through neuroimmune and autonomic modulation. Providing these modalities to patients through multidisciplinary ERAS pathways may redefine the goal of functional recovery from complication avoidance to functional restoration and personalized perioperative care.

INTRODUCTION

Postoperative gastrointestinal dysfunction (PGD), such as delayed bowel motility, abdominal distension, nausea, and postoperative ileus, is a common and clinically relevant complication following abdominal surgery, even with standardization of enhanced recovery after surgery (ERAS) pathways[1-3]. Although ERAS protocols emphasize multimodal perioperative optimization, rapid and sustained recovery of gastrointestinal function remains challenging in a significant number of patients, prolonging hospital stay and increasing health care burden[4-6].

In recent years, there have been many ERAS pathways developed for various surgical procedures. Specific nonpharmacological interventions have attracted increasing interest[7-9]. Among these, acupuncture, electroacupuncture, and transcutaneous electrical acupoint stimulation (TEAS) are worthy of special mention[10-14]. Various randomized controlled trials and meta-analyses indicate that these modalities can reduce time to first flatus, first defecation, and first bowel sound recovery, while also reducing postoperative pain and nausea[15,16].

Studies have shown that, in addition to neural modulation, acupuncture directly influences gastrointestinal function[17,18]. Moreover, it seems to affect the immune system and prevent inflammation that can be triggered upon surgical stress and inflammatory responses[19-23]. Intervention protocols, acupoint selection, and outcome measures varied between studies making it difficult to integrate acupuncture in ERAS care model[24-26].

This opinion review aims to provide a perspective on current evidence on acupuncture and non-pharmacological interventions within ERAS pathways for enhancing gastrointestinal recovery after abdominal surgery with a focus on efficacy, mechanisms, safety and clinical integration, and to provide a conceptual shift to redefine functional recovery in modern perioperative medicine. Relevant literature was identified through targeted searches in major databases (e.g., PubMed and Web of Science), focusing on representative clinical trials, meta-analyses, and mechanistic studies to support key concepts rather than exhaustive systematic inclusion. A mechanistic framework (Figure 1) is illustrated to provide a conceptual overview of how acupuncture and non-pharmacological interventions may be integrated into ERAS pathways to promote postoperative gastrointestinal functional recovery.

Figure 1 Conceptual framework of acupuncture and non-pharmacological interventions integrated into enhanced recovery after surgery pathways for enhancing gastrointestinal functional recovery after abdominal surgery. ERAS: Enhanced recovery after surgery; TEAS: Transcutaneous electrical acupoint stimulation; GI: Gastrointestinal.

BURDEN OF PGD IN THE ERAS ERA

Even though minimally invasive surgery and ERAS have been introduced, PGD and postoperative ileus remain main contributors to delayed recovery after an abdominal procedure[27-29]. The genesis of such complications involves multiple mechanisms, including surgical stress, the influence of opioids, activation of the inflammatory process and autonomic imbalance[2,30].

Current medications like prokinetics and opioid-sparing strategies help very little, and have inconsistent effects, stressing the need for other therapies[4]. Redefining recovery measures to include gastrointestinal functional endpoints has become important as perioperative care transitions from complication management to functional restoration[31-33].

EFFICACY OF ACUPUNCTURE AND NON-PHARMACOLOGICAL INTERVENTIONS IN GASTROINTESTINAL RECOVERY

Clinical evidence from randomized trials and meta-analyses

Research shows that acupuncture-based treatments can help patients recover more quickly from surgery, although these findings should be interpreted with caution given the heterogeneity of study designs and intervention protocols[34]. Multiple meta-analyses report a reduction in time to first flatus, first defecation and recovery of bowel sounds after abdominal and colorectal surgeries[5,15,35].

Electroacupuncture of the acupoints ST36 and PC6 was superior to standard care or sham intervention in improving gastrointestinal motility and relieving symptoms in a consistent manner[27,36-38]. In addition, TEAS combined with electroacupuncture may have synergistic effects and further shorten recovery time and hospital stay[39-41].

The study suggests that different methods like thumbtack needle therapy and multimodal acupoint stimulation can be practically applied to help improve post-operative gastrointestinal function in ERAS[1,42]. The primary features, mechanisms, safety profiles and clinical implication of acupuncture and related non-pharmacological interventions of ERAS pathways are summarized in Table 1, while detailed descriptions in the main text are streamlined to avoid redundancy.

Table 1 Summary of acupuncture and non-pharmacological interventions within enhanced recovery after surgery pathways for enhancing gastrointestinal recovery after abdominal surgery.

Category	Key components	Main findings on gastrointestinal recovery	Mechanistic basis	Safety profile	Clinical implications
EA	EA at ST36, PC6, ST37 and related acupoints	Significantly shortens time to first flatus, defecation, and bowel sound recovery; reduces postoperative ileus and hospital stay	Vagal nerve activation, neuroimmune modulation, anti-inflammatory signaling, regulation of enteric nervous system	Generally safe with minimal mild adverse events	Effective core adjunct modality for ERAS to accelerate functional recovery after abdominal surgery
TEAS	Non-invasive electrical stimulation at specific acupoints	Improves bowel motility, reduces postoperative nausea and vomiting, enhances early gastrointestinal function restoration	Autonomic nervous system regulation and brain-gut axis modulation	High safety and patient acceptability due to non-invasive nature	Suitable for standardized integration into perioperative ERAS protocols
Combined EA + TEAS	Multimodal acupoint stimulation strategies	Additive or synergistic effects on gastrointestinal recovery and shorter length of hospital stay	Enhanced neuroimmune and autonomic co-regulation	Favorable safety with good tolerability	Promising optimized strategy for multimodal ERAS care
Thumbtack needle and intradermal acupuncture	Continuous low-intensity acupoint stimulation	Accelerates recovery of bowel sounds and exhaust time; improves postoperative symptoms	Sustained neuromodulation and microcirculation improvement	Minimal complications and high compliance	Practical for long-duration perioperative stimulation within ERAS pathways
Acupuncture plus rehabilitation or integrative therapies	Acupuncture combined with rehabilitation or multimodal care	Further improvement in gastrointestinal recovery, symptom relief, and quality of recovery	Multi-target regulation including neural, immune, and hormonal pathways	Safe with low incidence of adverse events	Supports multidisciplinary perioperative recovery models
Other non-pharmacological ERAS components	Gum chewing, early mobilization, supportive NPIs	Moderate improvement in intestinal motility and symptom relief	Gastrointestinal reflex stimulation and autonomic activation	Generally safe	Complementary strategies but usually less effective than acupuncture-based interventions
Mechanistic evidence (overall)	Neuroimmune and autonomic modulation pathways	Restoration of gastrointestinal motility and reduced inflammation contributing to faster recovery	Vagal tone enhancement, cytokine inhibition (e.g., inflammatory mediators), brain-gut axis regulation	Mechanistically plausible and biologically supported	Provides theoretical basis for integrating acupuncture into ERAS
Safety and feasibility in ERAS	Multimodal non-pharmacological integration	No significant increase in postoperative complications; improved patient-centered outcomes	Non-pharmacological neuromodulation without systemic drug burden	Excellent overall safety profile	Feasible, acceptable, and cost-effective adjunct in modern ERAS pathways

EA: Electroacupuncture; ERAS: Enhanced recovery after surgery; TEAS: Transcutaneous electrical acupoint stimulation; NPIs: Non-pharmacological interventions.

Comparative effectiveness of different non-pharmacological modalities

In addition to acupuncture, there have been studies on gum chewing, rehabilitation, and multimodal supportive therapies as non-pharmacological ERAS components, which have demonstrated modest but consistent benefits in promoting gastrointestinal motility within ERAS pathways[43]. But generally, acupuncture has been reported as a promising modality for promoting gastrointestinal recovery in some analyses, although direct comparisons with other ERAS components remain limited and should be interpreted cautiously[44-46]. Network meta-analyses suggest that invasive acupuncture and electroacupuncture are superior to single-support strategies and combined non-pharmacological treatments have additive benefits on postoperative ileus and recovery quality, highlighting their potential role as adjunctive rather than replacement strategies within multimodal ERAS protocols[44,47-49].

MECHANISTIC BASIS: NEUROIMMUNE AND AUTONOMIC REGULATION

Vagal nerve and brain-gut axis modulation

Studies suggest that acupuncture primarily exerts its effects through modulation of the autonomic nervous system and brain-gut axis[2,11,50]. Experimental evidence suggests that electroacupuncture has the capacity to enhance vagal tone and restore gastrointestinal motility through neuroimmune pathways[19,20]. Activation of α7 nicotinic acetylcholine receptors and the cholinergic anti-inflammatory pathway, is involved in the improvement of postoperative ileus[51].

Anti-inflammatory and neuroimmune effects

PGD pathophysiology is mainly caused by postoperative inflammation[52]. Research suggests that acupuncture reduces pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-α and inhibits T helper cell 1 inflammatory responses, which may ameliorate intestinal inflammation and accelerate motility recovery[20,53-55]. The multi-target regulatory effects of acupuncture on various neurohumoral factors involved in perioperative regulatory effects may be due to the modulation of gastrointestinal hormones, neurotransmitters and microcirculation[56-58].

SAFETY PROFILE AND CLINICAL FEASIBILITY

Overall, acupuncture or related nonpharmacological interventions are considered safe, with no reports of severe adverse events in various clinical trials and systematic reviews[5,10,59]. According to Zhou et al[53], when these procedures are added to ERAS pathways, there is no substantial increase in postoperative complications[1,53,60]. Techniques such as TEAS and thumbtack needles provide added convenience, sustained stimulation, patient mobilization, and high acceptability, facilitating inclusion in multidisciplinary perioperative care models[1,47,61].

INTEGRATION OF ACUPUNCTURE INTO MULTIDISCIPLINARY ERAS PATHWAYS

Multiple studies indicate that acupuncture can be effectively integrated into standardized ERAS protocols, and may improve recovery outcomes and not interrupt the routine perioperative workflow[4,40]. Acupuncture-based neuromodulatory intervention may be a useful adjunct non-pharmacological measure to improve gastrointestinal motility restoration within the multimodal perioperative optimization framework of ERAS which emphasizes early mobilization, opioid-sparing analgesia and functional recovery[62]. Multimodal integrative programs that combine acupuncture, rehabilitation and conventional medical management have effectively resulted in reduced hospital stay and postoperative complications[63].

Despite the promising results of studies on direct brain stimulation and other procedures, they are not without challenges. These challenges include lack of standardized protocols, variability in practitioner expertise, and limited consensus on optimal timing and stimulation parameters[24,25]. Limited awareness, insufficient interdisciplinary collaboration, and lack of institutional support hinder large-scale adoption in ERAS global guidelines.

LIMITATIONS OF CURRENT EVIDENCE AND FUTURE DIRECTIONS

The current literature is heterogeneous in study design, acupoint, and outcomes making them incomparable which limits synthesizing the evidence, and may introduce potential bias in estimating treatment effects[25,64]. Moreover, a lot of clinical studies that exist have small samples, different types of acupuncture interventions and different definitions of gastrointestinal recovery. Thus, their benefits may not be generalizable. Numerous trials have limited sample sizes, inadequate blinding, and limited follow-up duration, limiting their ability to draw long-term conclusions[5].

Future investigations should place a premium on multi-center randomized controlled trials with standardized acupuncture protocols along with objective biomarkers of gastrointestinal motility as well as long-term patient centered outcomes. Studies of mechanisms involving neuroimaging, inflammation, and autonomics must also be included for clarity of biological mechanisms and optimal use[2,11].

CONCLUSION

To summarize, there is a growing body of evidence supporting the use of acupuncture and other related non-pharmacological treatments as adjuncts in ERAS pathways, although current findings are limited by heterogeneity and methodological variability. The aforementioned modalities have been associated with faster restoration of gastrointestinal function in many studies, although the current evidence remains heterogeneous and should be interpreted with caution. In spite of being feasible and clinically promising, challenges remain in its clinical application such as standardization, mechanistic clarification, and implementation at scale in clinical ERAS protocols. In the future, high-quality multicenter randomized controlled trials with standardized intervention protocols and outcome measures are required to refine treatment parameters and establish evidence-based guidelines. In turn, this would redefine postoperative recovery beyond mere complication prevention towards the full restoration of functions.