Appendix 1:

Exclusion criteria

Subjects who satisfied any one of the following exclusion criteria were not eligible for this study: Transvesically measured postvoid residual volume >400 mL Currently in urinary retention Chronic urinary retention Medications impairing bladder contractibility Uncorrectable bleeding disorders or long-term anticoagulation that cannot be stopped Recent myocardial infarction or coronary artery stent placement Any of the following diseases which appear to involve the bladder: myasthenia gravis, diabetes neuropathy, multiple sclerosis, spinal cord injury, or Parkinson’s disease Any patient with idiopathic atonic bladder Major pelvic fractures that involved damage to the external urinary sphincter Recently completed definitive radiation therapy for prostate cancer Active localized or systemic infections; including active urinary tract infection Active cystolithiasis, urethral strictures, bladder neck contracture, or acute prostatitis affecting bladder function If patient’s PSA value >PSA age-adjusted normal value, patient needs to have a negative biopsy before participating in the study Confirmed malignancy of the prostate Bladder cancer treated with TURBT within 12 months or any patients treated with BCG Bilateral hydronephrosis on renal ultrasound Urethral strictures or a residual volume >400 mL Immunocompromised Previous TURP

PSA: prostate-specific antigen; TURBT: transurethral resection of bladder cancer; BCG: Bacillius Calmette-Guerin; TURP: transurethral resection of the prostate.