Evaluation of Tadalafil in Combination with Low-Intensity Pulsed Ultrasound (LIPUS) for Erectile Dysfunction: A Protocol for a Randomized Controlled Trial (SPIRIT Compliant)

Background Erectile dysfunction (ED) is characterized by a persistent inability to achieve and maintain sufficient penile erection for satisfactory sexual performance persisting for at least six months. Low-intensity pulsed ultrasound (LIPUS), a noninvasive therapy, has shown potential in improving ED by promoting the regeneration of connective tissue, blood vessels, and cavernous nerves, as well as reducing inflammation. This study aims to evaluate the clinical efficacy and histological changes in the corpus cavernosum of patients with ED treated with tadalafil combined with LIPUS through a randomized controlled trial. Methods This study will enroll 114 patients diagnosed with ED who will be randomly assigned to either the treatment group or the control group in a 1:1 ratio using simple random sampling. The treatment group will first receive 5 mg of tadalafil daily combined with twice-weekly LIPUS therapy for 4 weeks. Following a 4-week interval with daily 5 mg tadalafil alone (no LIPUS treatment), the same combined treatment regimen will be repeated. The control group will receive only 5 mg of tadalafil daily. The primary outcome will be assessed using the minimal clinically important difference (MCID) based on the International Index of Erectile Function-5 (IIEF-5) at each follow-up visit. Additional assessments will include the Erection Hardness Score (EHS), penile blood flow parameters, and elasticity values for a comprehensive evaluation. Discussion The study aims to evaluate the efficacy of tadalafil combined with LIPUS for treating ED and to improve the evaluation of treatment response in erectile dysfunction by integrating blood flow parameters and two-dimensional shear wave elastography. Trial registration : Trial registration: ClinicalTrials.gov, NCT06543628. Registered 5th August 2024, https://clinicaltrials.gov/study/NCT06543628