Botulinum Toxin Urethral Sphincter Injection for Dysfunctional Voiding

Inclusion Criteria: * Adults with age of 20 years old or above. * Free of active urinary tract infection. * Free of bladder outlet obstruction on enrollment. * Patients should have severe dysuria or urinary retention, large residual urine and have been treated with medication or other therapeutic modality for over 3 months. Exclusion Criteria: * Patients with severe cardiopulmonary disease and such as congestive heart failure, arrhythmia, poorly controlled hypertension, not able to receive regular follow-up. * Patients with bladder outlet obstruction on enrollment. * Patients with uncontrolled confirmed diagnosis of acute urinary tract infection. * Patients have laboratory abnormalities at screening including: Alanine aminotransferase (ALT) \> 3 x upper limit of normal range aspartate aminotransferase (AST) \> 3 x upper limit of normal range. * Patients have abnormal serum creatinine level \> 2 x upper limit of normal range. * Patients with any contraindication to be urethral catheterization during treatment. * Female patients who is pregnant, lactating, or with child-bearing potential without contraception. * Patients with any other serious disease considered by the investigator not suitable for general anesthesia or in the condition to enter the trial. * Patients participated investigational drug trial within 1 month before entering this study. * Written informed consent has been obtained.