Title of the invention: URETHRA PROTECTION DEVICE Field of invention

The present invention relates generally to surgical instrument for protecting the lumen such as urethra during surgery such as sling procedure or any other surgery performed close to the lumen. More particularly, the invention provides a device to prevent inadvertent injury to the lumen during the surgical procedure such as sling surgery for stress urinary incontinence, anterior repair or vaginal vault repair, posterior sling, uterine suspension, cholecystectomy, transgastric procedure.

Background of the Invention

Female stress uήnary incontinence, defined as the unintentional loss of urine, is caused by anatomical defect function in the tissues or ligaments connecting the vagina wall with the pelvic muscles and pubic bone. Urinary incontinence not only affects number of female patients worldwide but also disturbs their normal day-to-day lifestyle and social appearances. Such a defect results in an improperly functioning urethra.

Various approaches have been devised in last few decades to treat mis problem. Those skilled in the art will be familiar with approaches ranging from pelvic floor exercises to surgical techniques such as Burch colposuspension in which sutures are placed around the bladder neck and Stamey-type endoscopic procedures in which loop sutures are placed so as to elevate the bladder neck.

Anatomically, the term "retropubic space" means that region of the female body that is posterior to the pubic bone (i.e. the region that is posterior to the pubic ramus and pubic symphysis). This is an area of loose connective tissue between the bladder with its related fascia and the pubis. It includes endopelvic fascia. The retropubic space extends upward to the rectus fascia, but does not include the suprapubic area with the rectus fascia itself. The retropubic space does not extend beyond the sacrum. The phrases "space of Retzius" or "cave of Retzius" is also used to describe portions of the retropubic space.

The term "endopelvic fascia" means tissue that covers the pelvic organs and surrounds vessels and nerves in the pelvic region (e.g. in the subperitoneal space). Endopelvic fascia includes collagen, elastin and smooth muscle. These structures surround and support the viscera in the pelvic cavity and extend from the pelvic floor to the rectus fascia and respiratory diaphragm. As used herein, endopelvic fascia can include pubocervical fascia and periurethral fascia. Endopelvic fascia is also referred to as visceral pelvic fascia.

The term "pubocervical fascia" means a sheet of thick fibrous tissue that is located on the vagina underneath the bladder. Pubocervical fascia is anterior vaginal fascia that fuses with vaginal tissue, providing a hammock for the urethra and bladder. Projrimally, the pubocervical fascia attaches to the cervix; distally it extends beneath the urethra and fuses with the perineal membrane of the ureogenital triangle; and laterally, it is connected to the pelvic wall at the fascial white line (arcus tendineus fasciae pelvis). The pubocervical fascia forms a horizontal platform that supports the bladder, and its anterior portion supports the urethra With increased abdominal pressure, the lower urinary tract is forced inferiorly and compressed against the pubocervical fascia while this fascial layer displaces to a lesser degree because of its elastic suspensory characteristics.

The use of sling to correct stress urinary incontinence has existed since the late 1990's. Understanding of the physiopathological concepts of female stress urinary incontinence (SUI) has consistently improved over the past decades and their application has lead to the development of numerous surgical techniques aimed at curing this disorder.

US Patent No. 5,1 12,344 discloses a method for treating female urinary incontinence without the necessity of opening the abdomen, which would require hospital care for may be four days. In this method a filamentary element (or mesh tape) is looped around the muscle tissue of the abdomen to either side of urethra to be implanted into the soft tissue between the vaginal wall and the abdominal wall extending over pubis and with the ends of the tape extending into vagina The tape is left in the body in order that fibrous ήssue shall develop around the tape, said scar tissue functioning as a supporting ligament in the

soft tissue. The tape is removed from the body when such scar tissue has developed, which may take about two months.

There are various reports of accidental injury urethra during such procedures. Surgeons need to check for such injury and correct the same, if any, during the procedure. Considerable time is spent in correcting such injuries. Also, urinary catheter is inserted and kept inserted for 3 - 4 days to allow the injury to heal. This causes discomfort and inconvenience to the patient. There are published research papers which discuss the other complication associated such urethral injury.

With above description as an example, other surgical procedure may be described such as posterior sling which is useful for vault suspension wherein a sling in passed through the posterior fornix in vaginal to para-rectal tissue. During such procedure, the surgeon needs to be careful not to damage the lumen of the rectum as this will create a major surgical complication.

Similarly for other surgical procedures involving lumen such as transgastric procedures or cholecystectomy or vessel harvesting, it is important to guide the surgical instrument such that it does not damage or injure the lumen.

The present invention provides a device, which when used during the surgical procedure is expected to reduce such inadvertent injuries to a significant extent.

Summary of invention

A device to prevent accidental injury to lumen is disclosed. The surgical instrument is used for protecting the lumen during surgery such as sling surgery or any other surgery performed close to any lumen. More particularly, the invention provides a device to prevent inadvertent injury to the urethra during the surgical procedure such as sling surgery for stress urinary incontinence, anterior repair or vaginal vault repair.

In one aspect of the invention, the device comprises of lumen probe or a shaft or a rod, a guard or a plate and mechanism to synchronize die said probe and said guard.

In other aspect of the invention, die said guard has wings which insert into the incision to keep the incision open during the surgery

In another aspect of the invention, the said lumen probe and Ae guard has handles which are designed in such a way that there is less interference with the surgical site.

In yet another aspect of the invention, the device, when held with reference to anatomical landmark such as pubic bone, the guard is parallel to the lumen protecting it.

In another aspect of the invention, the said guard, guides the deployment device or instrument so as to achieve particular angle of deployment

In another aspect of the invention, the guard is made into two smaller guards, which can be approximated to hold the lumen.

The device can be used with any surgical approach such as transobturator, retropubic or smaller mesh used in procedures like TVT - Secur, Gyneideas or such like.

Brief description of drawings

The attached drawings are sufficient to describe the device in detail and make the person skilled in the art understand the device construction and use.

Fig 1 is an isometric view of the first embodiment of lumen protection device. This figure shows construction of the device, lower and upper arm.

Fig 2 is a side view representation of the first embodiment showing the direction of working of the device

Fig 3 is an isometric view of the second embodiment of the lumen protection device.

Fig 4 is a schematic representation of the use of second embodiment of the device in lithotomy position of human female pelvis

Fig 5 is a schematic representation of the use of first embodiment of the device in sectional view of human female pelvis

Detail description of the invention

Device to protect the anatomical lumen such as urethra from damage during surgery is disclosed. The device will be useful in protecting the lumen even during other surgeries such as anterior repair, stress urinary incontinence procedure, vaginal repair, vault repair, cholecystectomy, or vessel harvesting.

The device comprises of a lumen probe and mechanism to protect the lumen during passage of the instrument around the lumen. As an example the device construction may comprise of a urethral probe, a thin sheet of tough material such as steel to guard the urethra and a clip like mechanism to control the movement of urethra probe with respect to the guard so as to protect the urethra during sling surgery.

In the first embodiment, as shown in fig 1 the device comprises of lumen probe 1 and lumen guard 5. The lumen probe and lumen guard is hinged at pin 25. Spring can be attached in hole 30 to keep the two arms close to each other under tension. The handle 15 of the lumen probe and handle 20 of the guard is pinched to open the device. The probe 1 is inserted in the lumen and guard 5 is placed around the lumen. As shown in fig 2, the distance 35 between the lumen probe and lumen guard is sufficient to keep the two probes parallel or as desired. The distance 35 can be adjusted in another embodiment.

To place a sling during sling surgery, an incision is made of the anterior vaginal wall. The lumen guard acting as urethral guard 5 is placed under the urethra after the incision.

In another embodiment, the urethral guard 5 has wing projections 10. These projections may be used to locate the incision or may also be used to keep the incision open. The

wings 10 can be used to guide the needle during sling surgery. Also, the wings 10, can be modified further to have specific shape to guide the needle during the sling surgery.

Fig 5 shows the schematic representation of the use of device in human female pelvic cross-section. In the fig 5, 75 is the vaginal opening and 85 is the urethral opening. Once the device is in place, the needle 70 may be inserted past the guard in the pelvic tissue 90. Once the needle is passed on both the sides, the urethral guard may be removed before further tensioning the mesh. The needles may then be removed as per the specific design of the sling procedure.

In another embodiment as shown in fig 3, device is made of urethral probe 50 and urethral guard 45. They are attached to handle 105 and 100 respectively. Spring 55 may be attached to produce tension between the two arms 50 and 45 is required.

As shown the fig 4, the device may be used in a vertical position. As described earlier, the urethral probe and urethral guard is inserted into the urethra and vagina respectively.

The device when placed in the urethra and vagina can be of help to understand the relative position of urethra, vagina and the incision. This helps the surgeon to maneuver the needles for the sling surgery to avoid the urethra.

In another embodiment, the device is pushed to the left side 110 when the right needle is being inserted. When the device is pushed in say the left side, the guard covers more of the right paraurethral space and hence allows for safer insertion of the needle in the right space. The same may be applied to left paraurethral space.

Similarly the device may be used to protect the rectum during the sling surgery wherein the lumen probe as a anal probe and guard is either placed in the vagina or on the dorsal side of the patient.

In another embodiment, the device comprises of lumen probe and a mechanism to guide the instrument such as needles around the lumen wherein there is no specific guard to protect the lumen but the needles are guided in such as fashion as to not injure the lumen during passage.

In some advance deployment devices, the lumen probe may act as a locator and an elaborate deployment mechanism may be build to deploy the needles in pre-guided direction and location.