Pain Relief During Cystoscopic Ureteral Stent Extraction by Transcutaneous Electrical Acupoint Stimulation: A Double-Blinded, Randomized, Controlled Trial

Qiaoling Chen,1,* Huidan Lian,2,* Junlu Wang,2,* Lili Chen,3 Ruolin Shi,4 Meizi Qian2 1Operating Room, Pingyang Hospital Affiliated to Wenzhou Medical University, Pingyang County, Wenzhou, Zhejiang, 325400, People’s Republic of China; 2Department of Anesthesia, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People’s Republic of China; 3Department of Nursing, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People’s Republic of China; 4Operating Room, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ruolin Shi, Operating Room, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People’s Republic of China, Email [email protected] Meizi Qian, Department of Anesthesia, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People’s Republic of China, Email [email protected]: Acupuncture has pain-relief effects, but no data are available on transcutaneous electrical acupoint stimulation (TEAS) for pain relief during transurethral removal of ureteral stents. This study aimed to evaluate the efficacy of TEAS in reducing pain during cystoscopic ureteral stent extraction.Methods: This prospective, double-blinded, randomized controlled trial enrolled 122 patients scheduled for cystoscopic ureteral stent removal between June 2023 and March 2024. Participants were randomized into three groups: TEAS at Hegu (LI4) and Neiguan (PC6) (Group A, n=37), TEAS at Sanyinjiao (SP6) and Zusanli (ST36) (Group B, n=38), and sham TEAS (Group C, n=47). TEAS or sham TEAS were administered 30 minutes before the procedure. The primary endpoint was pain measured by visual analog scale (VAS) at stent removal (T2). Secondary endpoints included VAS at cystoscope insertion (T1) and 10 minutes post-procedure (T3), along with hemodynamic parameters.Results: Baseline characteristics were comparable (p > 0.05). Both TEAS groups showed significantly lower VAS scores during stent removal (T2: median 0.00 [IQR: 0.00– 2.50] for Group A and median 0.00 [IQR0.00– 2.50] for group B vs 0.00 [IQR: 2.00– 5.00] for Group C; p = 0.027) and at 10 minutes post-procedure (T3: median 0.00 [IQR: 0.00– 0.00] for Group A and median 0.00 [IQR0.00– 1.00] for group B vs 0.00 [IQR: 0.00– 2.00] for Group C; p = 0.012). Repeated measures ANOVA with gender and age group as covariates revealed a significant Time × Gender interaction (F = 7.044, p = 0.006), indicating different temporal patterns of pain reduction between males and females. However, no significant interaction was found involving the Age Group factor or the three-way interaction with the treatment groups. No significant hemodynamic differences were observed. One patient in Group C withdrew due to severe pain.Conclusion: TEAS effectively reduces procedural and post-procedural pain during cystoscopic ureteral stent extraction without affecting hemodynamic stability. Notably, the analgesic effect of TEAS demonstrated gender-specific temporal patterns (Time × Gender interaction, p = 0.006), being more pronounced in female patients, while remaining consistently effective across all age groups. These findings support TEAS as a valuable non-pharmacological analgesic adjunct in outpatient urological procedures, though further multicenter and heterogeneous population studies are warranted to validate its generalizability.Keywords: transcutaneous electrical acupoint stimulation, TEAS, cystoscopic ureteral stent extraction, randomized controlled trial, pain management