RESUMEN
PURPOSE: Urethral pain syndrome is a chronic condition characterized by disturbing feeling or server pain sensed at the urethra without specific treatment. This double-center, two-arm controlled trial aimed to explore the efficacy of electrical pudendal nerve stimulation (EPNS) versus intravesical instillation (II) of heparin and alkalinized lidocaine for urethral pain syndrome (UPS). METHODS: Eighty eligible patients took three sessions of EPNS, or 1 session of II per week, for 6 consecutive weeks. The primary end point was the change of pelvic pain and urgency/frequency symptom (PUF) score from baseline to week 6. Secondary outcome measures included changes of visual analogue scale (VAS) score and three sub-score extracted from PUF score. RESULTS: The enrolled participants were all included in the intention-to-treat analyses, and baseline characteristics between the two groups were well balanced. The post-treatment PUF score decreased by 10.0 (7.00, 16.50) in the EPNS group, and by 7.0 (3.00, 10.00) in the II group. At the closure of treatment, the medians of changes in symptom score, bother score, pain-related score and VAS score were 6.50 (4.25, 10.00), 4.00 (2.00, 6.00), 6.00 (5.00, 8.00),4.50 (2.25, 6.00), respectively, in the EPNS group, and 4.00 (2.00, 7.00), 3.00 (1.00, 3.00), 3.00 (2.00, 6.00), 2.00 (1.00, 4.00), respectively, in the II group. All the between-group differences were statistically significant. CONCLUSION: Compared with the II, the EPNS results in superior pain control and better relief of lower urinary tract symptoms, and deserves further attention. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03671993).