1.  Field of the Invention
The present invention relates generally to a surgical instrument and a method for treating female urinary incontinence and in particular to a needle and mesh configuration for creating a sling beneath the urethra. 
2.  Background Discussion
Women account for more than 11 million of incontinence cases.  Moreover, a majority of women with incontinence suffer from stress urinary incontinence (SUIT).  Women with SUIT involuntarily lose urine during normal daily activities and movements, such as laughing, coughing, sneezing and regular exercise. 
SUI may be caused by a functional defect of the tissue or ligaments connecting the vaginal wall with the pelvic muscles and pubic bone.  Common causes include repetitive straining of the pelvic muscles, childbirth, loss of pelvic muscle tone, and estrogen loss.  Such a defect results in an improperly functioning urethra.  Unlike other types of incontinence, SUI is not a problem of the bladder. 
Normally, the urethra, when properly supported by strong pelvic floor muscles and healthy connective tissue, maintains a tight seal to prevent involuntary loss of urine.  When a woman suffers from the most common form of SUI, however, weakened muscle and pelvic tissues are unable to adequately support the urethra in its correct position.  As a result, during normal movements when pressure is exerted on the bladder from the diaphragm, the urethra cannot retain its seal, permitting urine to escape.  Because SUI is both embarrassing and unpredictable, many women with SUI avoid an active lifestyle, shying away from social situations. 
U.S. Pat.  No.  5,112,344 describes a method and apparatus for treating female incontinence.  The surgical instrument for the application of a filamentary element into the body comprises a tubular shaft having a handle at one end and a flexible needle slidably receivable in the shaft and adapted at one end to receive a filamentary element.  The method of treating female incontinence comprises looping a filamentary element between the wall of the vagina and the rectus abdominis sheath in the anterior wall of the abdomen whereby it passes to each side of the urethra, tightening the loop to bring the vaginal wall and the urethra into the correct spatial relationship to the pubis allowing the development of scar tissue between the vaginal wall and the anterior wall of the abdomen pubic symphysis and removing the filamentary element. 
U.S. Pat.  No.  5,899,909 discloses a surgical instrument comprising a shank having a handle at one end and connecting means at the other end to receive, one at a time, two curved needle-like elements which are connected at one end to one end of a mesh intended to be implanted into the body.  In practice, the mesh is passed into the body via the vagina first at one end and then at the other end at one side and the other, respectively, of the urethra to form a loop around the urethra, located between the urethra and vaginal wall.  The mesh is extended over the pubis and through the abdominal wall and is tightened.  The mesh ends are cut at the abdominal wall, and the mesh is left implanted in the body.  This trans-vaginal procedure is exemplified by the TVT product sold by the Gynecare franchise of Ethicon Inc., a Johnson & Johnson Company, of Somerville, N.J., USA.  In this procedure two 5 mm needles pass a PROLENE mesh trans-vaginally and through the abdomen to create a tension-free support around the mid urethra.  U.S. Pat.  No.  5,899,909 is incorporated herein by reference in its entirety. 
An alternate method to treat SUI is the sling procedure.  In this procedure a needle or other suture-retrieving device is first inserted through the abdomen, above the pubic bone.  The needle is guided behind the pubic bone, through the subrapubic fascia around the urethra, and out of the body through an incision in the anterior vaginal wall.  At this point sutures are attached to the needle(s) and pulled up back through the abdominal cavity, where the sutures are fastened to the rectus muscle. 
Techniques for protecting against the puncture of the internal structures during this type of procedure have included laparoscopic procedures.  This involves making an incision in the abdomen and inserting a video scope to watch the progress of the needles as they pass through the abdominal cavity.  These additional incisions are not optimal for the patient.  Also, the needles which pass through the abdomen are not designed to capture a mesh but rather a suture which has been previously attached to the mesh or harvested fascia.  Thes is needles are generally in the diameter range of about 0.090 ins.  to about 0.120 inches.  Therefore, the needles do not create a large channel through the fascia.  The channel is only wide enough to pass the suture.  Accordingly, the sutures do not possess the elongation properties of the PROLENE mesh and therefore can not provide the tension-free support of the TVT.  Also attaching a mesh directly to these needles is not optimal because it is very difficult, if at all possible, to pull the mesh through the narrow channel created by the needle. 
It would be beneficial to provide a surgical system for use in implanting a mesh within a female body to prevent incontinence that can be implanted either through a trans-vaginal approach or a trans-abdominal approach. 
This invention addresses that need and overcomes the deficiencies of the prior art.