The objective of this study is to determine whether bilateral sacral nerve stimulation with First stage tined lead placement test is more effective than unilateral stimulation, among patients with non obstructive urinary retention.

Inclusion Criteria:

• Patients who signed the informed consent
• Patients (male and female), aged between 18-70 years, with non obstructive urinary retention.

Two specific subcategories of retention are included

1. Incomplete voiding or incomplete retention (>100 cc residual) such as hesitancy or intermittency, that are due to an acontractile detrusor or due to urethral sphincter overactivity. The overactivity of the sphincter may occur in absence of detrusor contraction and may be the cause of the lack of detrusor activity.
2. Complete retention. These individuals are completely unable to void.

All patients must have the potential for storing an adequate volume of urine:

i.e., at least 100 ml

Exclusion Criteria:

• Known psychiatric disorders
• Current or plans of pregnancy
• Known neurologic diseases or impairment; including DM (severe or uncontrolled diabetes; or diabetes with peripheral nerve involvement), spinal cord injury, MS
• Reiter's syndrome
• Concomitant medical conditions that would limit the success of the procedure such as: active degenerative disc disease, spinal cord injury< 6 months old, bleeding complications, CVA< 6 months old etc.
• Extra urethral incontinence
• Pelvic pain of uncertain etiology that is not associated with a voiding dysfunction or where pelvic pain is the primary complaint/ diagnosis.
• Anatomic obstructive voiding disorders
• Current urinary tract infection
• Malignancy of urinary tract
• Severe grade III/ IV pelvic prolapse, cystocele, urethrocele, enterocele
• Proven interstitial cystitis or clinical symptoms of interstitial cystitis