Efficacy of Low-Intensity Extracorporeal Shockwave Therapy in Treatment of Erectile Dysfunction - A Randomized Controlled Trial With Sham Therapy

Objectives

1. To investigate the efficacy and safety of LI-ESWT in treatment of moderate and severe ED
2. To investigate the effect of LI-ESWT on nocturnal penile tumescence and rigidity.

Research Plan and Methodology

1. Study Design This is a prospective, two-centre randomized controlled trial involving United Christian Hospital and Tseung Kwan O Hospital. The study will be conducted in accordance with the Declaration of Helsinki and the International Conference on Harmonisation, Good Clinical Practice Guidelines (ICH-GCP). This RCT will be registered with ClinicalTrials.gov.
2. Patient selection and recruitment Patients would be recruited in the urology outpatient clinics. Subjects who fulfilled selection criteria would be counselled to participate in the study. Written consent would be obtained.
3. Randomisation, allocation concealment and blinding Patients are randomised to either LI-ESWT or sham therapy in a ratio of 1:1. Randomisation is performed with a random number table. The designated operator who perform the procedure is not blinded. Patients were blinded throughout the procedures, during clinical follow-up and data analysis.
4. Study Intervention Patients would undergo a 4-week washout period of oral phosphodiesterase inhibitors after recruitment. Severity of ED would be assessed by the International Index of Erectile Function - Erectile Function Domain (IIEF-EF) & International Index of Erectile Function (IIEF-5) questionnaires and Erection Hardness Score(EHS) after the washout. Nocturnal penile tumescence (NPT) and rigidity would be measured by the Rigiscan at the night prior to the first treatment.

All procedures would be performed by a designated nurse consultant(co-investigator) in an office setting using an electromagnetic linear shockwave machine. The nurse consultant has received overseas andrology training, as well as on-hand machine operation training by ESWT product specialist. Patient would be positioned in a supine position. Shockwaves would be delivered to the stretched penis at proximal, mid and distal penile shaft and bilateral crura of penis. (Energy: 0.1-0.25 mJ/mm2; 3000pulses per session; Frequency 3Hz) Treatment consists of 6 sessions over 5 weeks in total. It would be a twice-weekly treatment with one-week interval of resting period. Patient would be discharged home after each treatment session. Sham therapy would be given with a modified probe which no shockwave would be emitted. A working noise would still be generated which mimicked active treatment. 5. Post-procedure management Clinical assessment would be conducted at week 4, week 26 and week 52 after completion of treatment. NPT would be measured at week 4. At all follow-up the IIEF-EF and EHS would be assessed. Any complications would be assessed and documented according to Clavien-Dindo classification. 6. Sample Size Calculation In a recent meta-analysis, the mean improvement in IIEF-EF was 4.23. At 5% significance level and 80% power, 33 subjects were needed in each treatment and sham group (Total 66 subjects). Overall 84 subjects would be recruited with 20% of drop out expected (i.e. 42 subjects in each group). 7. Study Period The expected study period would last for 44 months, including 30 months of subject enrolment, 2 months of treatment and 12 months of follow-up. 8. Statistical Analysis The results would be analysed according to intention-to-treat principle. Mann-whitney U test would be used to study the IIEF-EF results, as well as all other non-parametric continuous variables in secondary outcomes. Chi-square test would be used for categorical variable, independent samples t-test would be used for parametric continuous variable.