Vaginal slings or urinary incontinence slings are medical devices placed under the urethra through a small incision to treat incontinence symptoms. Stress urinary incontinence (SUI) can be classified in three forms: intrinsic sphincter deficiency (ISD), urethral hypermobility or male loss of internal and external sphincter functionality. Slings are commonly used in women who have urethral hypermobility. A sling will stop the hypermobility, but the patient may still have stress urinary incontinence due to an intrinsic sphincter deficiency (ISD). ISD occurs when the urethral sphincter is unable to generate enough resting pressure to prevent urine from seeping out. Urethral hypermobility, also known as Type II SUI, is due to weakened anatomic urethral support, often caused by childbearing. Male loss of sphincter functionality is relatively rare. Vaginal slings directly compete with bulking agents; however, slings are considered the leading technology for treating SUI.