Effect of Buccal Acupuncture with Patient-Controlled Analgesia on Pain, Inflammation, and Coagulation in Gastric Cancer Patients

Summary

Here, we present a protocol to study buccal acupuncture + PCIA in 142 GC patients to examine pain, inflammation, coagulation, and analgesic mechanisms.

Abstract

Buccal acupuncture combined with patient-controlled analgesia (PCIA) is commonly used after surgery. This study focused on the effects of acupuncture combined with PCIA on postoperative pain, inflammatory response, and coagulation function in patients with gastric cancer (GC). From March 2024 to January 2025, 142 GC patients were selected and assigned to a routine group (79 cases) and a buccal acupuncture group (63 cases). Pre- and postoperative levels of serum pain mediators (SP, PGE2, β-EP, and Glu), inflammatory markers (IL-6, TNF-α, IL-10, and CD11b), coagulation function parameters (PT, APTT, TT, D-D, and TAT), platelet activation (GP IIb/IIIa, CD62P, GMP-140, and PAC-1) were detected. Serological indexes indicated post-treatment reductions in SP, PGE2, and Glu as well as an elevation in β-EP in the buccal acupuncture group (P<0.05). Moreover, more pronounced decreases in IL-6 and CD11b, and increases in IL-10, were observed in the buccal acupuncture group compared to the routine group (P<0.05). Regarding blood coagulation function, lower post-treatment D-D, TAT, and sCD62P were observed in the buccal acupuncture group compared with the routine group (P<0.05). Meanwhile, GP IIb/IIIa, CD62P, GMP-140, and PAC-1 in the buccal acupuncture group were lower than in the routine group (P<0.05). Buccal acupuncture combined with PCIA may exert analgesic effects through multiple mechanisms, including regulating the balance of pain mediators, relieving inflammation, enhancing vascular endothelial function, and correcting a hypercoagulable state. It can also improve clinical analgesic outcomes and reduce opioid consumption with good safety.

Introduction

Laparoscopic surgery for gastric cancer (GC) is minimally invasive, yet postoperative pain, hyperinflammatory response, and coagulation disorders remain significant issues hindering patient recovery¹. Patient-controlled analgesia (PCIA) is the main program of postoperative analgesia in clinical practice², and its effect has been verified many times^3,4. In recent years, Traditional Chinese Medicine (TCM) has been internationally recognized for its excellent safety in clinical applications^5,6. Buccal acupuncture, as an emerging branch of TCM micro-acupuncture technology, has been confirmed in a number of studies that combined with PCIA can better improve the pain of patients after surgery⁷. Zhu DX et al. clearly pointed out that buccal acupuncture combined with PCIA can reduce postoperative pain in GC patients⁸. However, this study found that analgesic studies on buccal acupuncture combined with PCIA usually only observe the pain changes of patients from a subjective perspective, such as the visual analog scale (VAS)⁹. Few studies have explored the mechanism of acupuncture combined with PCIA from objective clinical indicators.

This study is the first to examine the effects of buccal acupuncture combined with PCIA on objective clinical indicators, including pain mediators, coagulation function, and platelet activation, in GC patients, thereby confirming the multisystem regulatory effects of buccal acupuncture on the human body. The results of this study will help clinicians to better understand the analgesic mechanism of buccal acupuncture combined with PCIA.

Protocol

The study received approval from the Hospital of Jiangnan University and adhered strictly to the principles of the Helsinki Declaration. This is a retrospective observational study, and clinical trial registration was not required in accordance with the relevant national guidelines for retrospective research at the time of study design and implementation. The reagents, consumables, and equipment needed are listed in the Table of Materials.

1. Research subjects

A retrospective study was conducted on 142 GC patients admitted to our hospital from March 2024 to January 2025. The sample size was calculated using PASS software.

Inclusion criteria: (1) Histologically confirmed GC (TNM stage I-III); (2) Planned or completed standard laparoscopic radical operation with D2 lymph node dissection; (3) Age 40–75 years, regardless of sex, with a body mass index (BMI) of 18.5–28 kg/m²; (4) No preoperative neoadjuvant chemoradiotherapy; (5) No non-protocol analgesic use within 24 h after operation.

Exclusion criteria: (1) Severe heart/liver/renal failure, autoimmune disease, active infections, or coagulation dysfunction; (2) Facial skin injuries or infections; (3) Long-term use of anticoagulants/antiplatelet drugs (e.g., warfarin, clopidogrel for >1 week); (4) Past chronic pain history (Visual Analogue Scale [VAS] score ≥4 persisting > 3 months); (5) Psychiatric or cognitive impairments; (6) Prior acupuncture treatment.

Among them, 79 patients received standard postoperative analgesia (routine group), and another 63 patients also received buccal acupuncture therapy (buccal acupuncture group) (Supplementary Figure 1). The two groups showed comparable baseline data, such as age, sex, and BMI (P>0.05, Table 1).

2. Grouping and interventions

PCIA pump (sufentanil 1.5 µg/kg + tropisetron 10 mg, background dose 2 mL/h), low-molecular-weight heparin (4000 IU daily starting 12 h post-surgery), and cefuroxime (1.5 g every 8 h for 24 h), and venous blood sampling for coagulation function was performed at 08:00 the next morning (12 h after LMWH administration, before the next dose) to avoid the direct influence of LMWH on coagulation index detection. All patients in both groups received the above standardized postoperative analgesia, anticoagulation, and anti-infection management, with routine vital sign monitoring and postoperative care in accordance with the clinical pathway for laparoscopic radical gastrectomy for GC.

1. Buccal acupuncture
   Buccal acupuncture intervention was initiated 12 h after surgery, once daily for 3 consecutive days, with the same acupoint selection and operative method for each treatment: the left dorsal, bilateral Zhongjiao, and Xiaojiao acupoints. Alcohol disinfection was performed before needle insertion. Using specialized disposable buccal acupuncture needles (0.18 mm × 13 mm), practitioners applied tube pressure before quick skin penetration, then inserted the needles vertically to a depth of 3 mm with a 30-min retention time. All needle insertion and manipulation were performed by licensed TCM acupuncturists with more than 5 years of clinical experience in buccal acupuncture to ensure intervention standardization.

3. Blood collection and testing

Fasting venous blood was collected from patients 1 day before surgery (baseline, before treatment) and 72 h after surgery (post-treatment) for the following tests:

1. Plasma enzyme-linked immunosorbent assay (ELISA)
   A capture antibody (diluted 1:100) was added to the 96-well plate and incubated at 4 °C overnight. Each well was blocked with 200 µL of 5% BSA-PBS, followed by the addition of 100 µL of the plasma sample to be tested (β-EP at 1:2 dilution, TAT at 1:10 dilution) and a 2-h incubation. Then, biotinylated secondary antibody (1:2000), Streptavidin-HRP, and TMB substrate were added in turn, with the OD value measured at 450 nm.
2. Serum ELISA
   50 µL of standard/sample was combined with 50 µL of antibody detection reagent for 2 h at room temperature. After adding 100 µL of streptavidin-HRP, the reaction was developed with 100 µL of TMB substrate and stopped with 2 M H₂SO₄. IL-6, TNF-α, and IL-10 levels were determined using dual-wavelength measurement at 450 nm/540 nm.
3. Radioimmunoassay
   EDTA plasma (1 mL) was acidified with 1% TFA and subjected to solid-phase extraction using a C18 column. Following the addition of the secondary antibody-PEG complex, the mixture was centrifuged (3500 × g, 20 min), and the SP precipitation radioactivity (cpm) was measured using a γ counter.
4. Chemiluminescence assay:
   An automated electrochemiluminescence analyzer was used to detect PGE2 levels.
   1. Flow cytometry
      After incubating with 100 µL of EDTA-anticoagulated whole blood and 5 µL of antibodies, 2mL of BD Pharm Lyse buffer was added. Samples were analyzed on a flow cytometer, and the mean fluorescence intensity (MFI) of CD11b, GP IIb/IIIa, CD62P, GMP-140, and PAC-1 was calculated using FlowJo v10.
   2. Coagulation function analysis
      ​An automated coagulation analyzer was utilized to detect PT, APTT, TT, and D-D levels.

4. Statistical analysis

Data analysis was conducted using SPSS 26.0. Chi-square tests were used to compare counting data [n(%)]. Continuous variables, reported as χ±s), were analyzed using the independent samples t-test (with paired t-tests for within-group comparisons). Bonferroni correction was used to adjust P values for multiple comparisons across multiple outcome indicators, and P values <0.05 were considered statistically significant.

Results

Effect of buccal acupuncture combined with PCIA on serum pain mediators
Baseline pain mediator levels were similar in the two groups (P>0.05). Post-intervention, both groups showed significant changes in the levels of these pain mediators, with marked reductions in SP, PGE2, and Glu as well as elevated β-EP (P<0.05). However, the buccal acupuncture group exhibited more pronounced improvements than the routine group (P<0.05) (Figure 1).

Discussion

This study is the first to systematically evaluate the multi-target regulatory effects of buccal acupuncture combined with PCIA therapy on pain mediators, inflammatory responses, and coagulation function in patients undergoing GC laparoscopic surgery. The results indicated that buccal acupuncture not only effectively alleviated pain (as evidenced by reduced SP, PGE2, and Glu and elevated β-EP) but also reduced inflammation (reflected in selective suppression of IL-6 and neutrophil CD11b expression) while mitigating ...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Buccal acupuncture	Maanshan Bond Medical Devices Co., LTD	Registration Number: 20202080581	Microneedle therapy for treating systemic diseases by needling specific acupoints on the cheek
Cefuroxime	Glaxo Wellcome UK Limited	Batch Number: H20020200	The second-generation cephalosporin antibiotics exert broad-spectrum antibacterial effects by inhibiting the synthesis of bacterial cell walls.
Electrochemiluminescence analyzer	Roche	cobas e 411	Medical detection equipment based on electrochemiluminescence technology detects trace substances through antigen-antibody reactions combined with electroluminescence signals.
Flow cytometer	Beckman Coulter	CytoFLEX nano	Instruments based on the principle of optical detection measure the physical and chemical characteristic parameters of cells in liquid flow to achieve automatic analysis and sorting of cells. ‌
Fully automatic blood coagulation analyzer	Mindray	C2000-A	The levels of coagulation factors, anticoagulation systems and fibrinolytic systems in human and animal blood samples were detected and analyzed through techniques such as coagulation method, chromogenic substrate method and immunoturbidimetry.
IL-10 ELISA Kit	Beijing Yishao Shenzhou Technology Co., LTD	SEKA10947
IL-6 ELISA Kit	Beijing Yishao Shenzhou Technology Co., LTD	KIT10395A	A biological detection tool based on antigen-antibody specific reactions and enzyme catalytic amplification systems is widely used in the fields of medicine, biology and environmental monitoring.
Low-molecular-weight heparin	Hainan General Alliance Pharmaceutical Co., LTD	Batch Number: H20010300	An antithrombin III -dependent antithrombotic drug, mainly used for the prevention and treatment of deep vein thrombosis, and is also suitable for the prevention of blood clots in hemodialysis.
PCIA pump	Henan Longshan Medical Devices Co., LTD	Registration Number: 20202140237	A medical device that helps patients relieve pain caused by surgery, trauma or chronic diseases by continuously or on-demand delivering painkillers to the body.
Radioimmunoassay analyzer	Revvity Biomedical (Shanghai) Co., LTD	GC-911r	An instrument used to determine the binding degree of radioactive markers and antibodies in the body, often employed to measure hormones, drugs, tumor markers, etc. in the blood.
SPSS	IMB	v.26.0	Used for data statistics, data mining and predictive analysis.
Sufentanil	EuroCept B.V.	Batch Number: H20150125	A potent opioid analgesic and also a specific μ -receptor agonist.
TNF-α ELISA Kit	Youlike (Shanghai) Life Sciences Co., LTD	YLK1341E
Tropisetron	Fu 'an Pharmaceutical Group Ningbo Tianheng Pharmaceutical Co., LTD	Batch Number: H20052460	A 5-HT3 receptor antagonist, mainly used for the prevention and treatment of nausea, vomiting and postoperative vomiting caused by cancer chemotherapy.