Pubovaginal sling is a procedure used to manage urinary incontinence, which is an underdiagnosed and underreported medical problem. [1, 2, 3, 4, 5, 6] Stress urinary incontinence (SUI) affects 15-60% of women. It is a disorder that affects both young and elderly individuals. For example, more than one fourth of nulliparous young college athletes experience SUI when participating in sports.
Female SUI may be broadly subcategorized into types I, II, and III, as follows:
Type I SUI is defined as urine loss occurring in the absence of urethral hypermobility. This is the mildest form of SUI.
Type II SUI is defined as urine loss occurring due to urethral hypermobility. This is also known as genuine stress urinary incontinence (GSUI).
Type III SUI is defined as urine leakage occurring from an intrinsic sphincter deficiency (ISD). ISD is a more complex form of female SUI.
The subcategories of female SUI can be ascertained by direct physical examination and by measuring an abdominal leak point pressure (ALPP). ALPP, also known as the Valsalva or stress leak point pressure, [7, 8] is defined as the lowest abdominal pressure necessary to cause urine leakage.
An ALPP less than 60 cm water is considered diagnostic of type III SUI, whereas an ALPP of 90-120 cm water is consistent with type II SUI. Values of 60-90 cm water reflect the presence of both type II and type III, in combination. An ALPP greater than 120 cm water is considered diagnostic of type I SUI. Recent experience suggests that leak point pressures need not be stratified as they were in the past, as new slings manage all types of SUI. The types of incontinence just listed are noted for descriptive and historical purposes only. 
Because of social stigma, an estimated 50-70% of women with urinary incontinence fail to seek medical evaluation and treatment. Of individuals with urinary incontinence, only 5% in the general community and 2% in nursing homes receive appropriate medical evaluation and treatment. Patients with urinary incontinence often endure this condition for 6-9 years before seeking medical therapy.
Pubovaginal sling procedures
Slings are becoming increasingly popular with urologists for the treatment of all types of female SUI. Pubovaginal slings have excellent overall success and durable cure rates (see the image below). The procedure involves placing a band of sling material directly under the bladder neck (ie, proximal urethra) or mid-urethra, which acts as a physical support to prevent bladder neck and urethral descent during physical activity. The sling also may augment the resting urethral closure pressure with increases in intra-abdominal pressure.
Von Giordano is usually credited with performing the first pubovaginal sling operation in 1907, using a gracilis muscle graft around the urethra. In 1914, Frangenheim used rectus abdominis muscle and fascia for pubovaginal slings. In 1942, Aldridge, Millin, and Read corrected urinary incontinence using fascial slings. In 1965, Zoedler and Boeminghous first introduced synthetic slings.
Several different sling procedures are currently used to treat incontinence. Whatever sling surgery is performed, one should use the technique that produces the best outcomes in the hands of that particular surgeon.
Historically, surgeons have used the rectus fascia pubovaginal sling for complex SUI after a failed anti-incontinence operation. In addition, surgeons performed this operation extensively for treatment of primary ISD.
Historically, surgeons have used the fascia lata sling for recurrent SUI after a failed anti-incontinence operation. Furthermore, this operation is used extensively for the treatment of primary ISD. If the abdominal tissues are weak and attenuated or if the vaginal tissues are atrophied or in short supply, constructing a pubovaginal sling from the leg fascia lata is an excellent choice. This procedure is more involved than the creation of the rectus fascial sling. The fascia lata sling gently compresses the bladder neck and increases the urethral resistance.
An alternative to a long rectus sling is construction of a short sling from a much smaller piece of abdominal fascia (rectus fascia suburethral sling). The surgical procedure is similar to that used for the rectus fascia pubovaginal sling, except that the harvested fascial tissue is much smaller and the operation time shorter. The advantage of this procedure is its simplicity. No extensive dissection in the suprapubic area is necessary, and the postoperative result is similar to that of the full-length fascial strip sling.
An alternative to a long fascia lata sling is the use of a postage stamp–sized patch of fascia lata from the outer thigh (fascia lata suburethral sling). The surgical procedure is similar to that for the fascia lata pubovaginal sling, except the harvested fascia is much smaller. This operation does not require extensive dissection in the thigh area, and the postoperative result is similar to that of the full-length fascia lata strip sling. Postoperative convalescence is shorter than that of the fascia lata pubovaginal sling procedure.
The vaginal wall suburethral sling helps restore urethral resistance by increasing urethral compression and improving mucosal coaptation of the bladder neck. This operation is attractive because it is simple and easy to perform. Postoperative complications are minimal, and the recuperative period is short. Vaginal sling surgery is relatively contraindicated in elderly women with atrophic vaginitis. If recognized before surgery, the atrophied vaginal wall may be revitalized with the administration of vaginal estrogen cream or tablets for 3-6 months.
The Gore-Tex patch sling compresses the bladder neck and restores the necessary urethral resistance to prevent involuntary SUI. This procedure is not performed commonly now and is described here more for historical purposes.
Recently introduced, tension-free vaginal tape (TVT) is a polypropylene-meshed tape that is placed at the mid-urethra.  The TVT device consists of polypropylene mesh tape (1.1 cm by 40 cm) covered by a plastic sheath and held by 2 stainless steel needles on both ends.
Studies by Mostafa et al and Zhang et al compared an adjustable anchored single incision mini-sling vs tension-free vaginal tape-obturator (TVT-O) in the management of female stress urinary incontinence. The studies reported that adjustable-anchored single incision mini-sling is associated with success rates when compared to standard midurethral sling at a minimum of 1-year follow-up and is a safe and effective treatment. [11, 12]
Future directions and controversies
Surgeons currently use a number of materials for constructing pubovaginal slings, with excellent outcomes. All types of SUI may be corrected with pubovaginal sling surgery. Serious complications from sling surgery are uncommon. The choice of sling material and sling surgery is predominantly one of surgeon preference, the condition of host fascia/tissue, and previous surgery. The ideal sling material to use and the method of fixation are controversial.
For recurrent SUI after vaginal or urethral erosion, it is advisable to use classic pubovaginal or hemislings constructed with rectus fascia; otherwise, the synthetic mid-urethral tension-free slings placed retrograde (tension-free vaginal tape [TVT]) or antegrade should suffice for most patients.
As better insight into the relationship between the sling materials and the host response is elucidated, the success rates of sling surgery will continue to improve. At present, synthetic polypropylene mesh mid-urethral slings seem to have some of the best durability with the least problems; they will be hard to improve on in the future.
In 2008 and later in 2011, the US Food and Drug Administration put an alert on the use of mesh in the vagina. While this primarily relates to vaginal prolapse mesh, the use of synthetic mesh in the vagina has come under scrutiny. One should, as always, go over the risks and benefits of the materials in advance of any surgical management. Still, synthetic mesh tapes (type 1 polypropylene mesh) has been the best studied material with the most stringent outcomes of any material ever, with the best outcomes. Perhaps tissue engineering using autologous stem cells is the next step in the evolution of pubovaginal slings for definitive correction of female SUI.
The common indications for pubovaginal sling surgery in women include SUI that affects quality of life and potential incontinence in a patient undergoing prolapse repair. Conservative treatment measures, including diet modification, pelvic floor exercises, smoking cessation, and weight loss, have typically failed in such patients. In addition, women at risk for generating high intra-abdominal pressures, including those who are obese, vigorous athletes, and those with chronic obstructive pulmonary disease, are well served by pubovaginal slings.
In men who have undergone prostatectomy and have ISD, the artificial urinary sphincter (AUS) is the criterion standard therapy. Researchers recently introduced the male sling as an alternative to AUS in correcting postprostatectomy incontinence. During a male sling operation, the surgeon places a supporting strap of material under the bulbar urethra and secures the suspension sutures to the pubic arch, next to the bulbar urethra.
Surgeons’ experience with the use of a male sling for SUI in men is still in its early stages, although many patients have undergone the procedure successfully and have had excellent results. A male sling seems best geared toward patients with milder degrees of incontinence (2-3 pads or fewer per day).
A clear contraindication to pubovaginal sling surgery is pure urge incontinence or mixed urinary incontinence (MUI) in which urge is the predominant component. An inherent risk of any sling procedure is de novo or worsening urge symptoms; thus, surgeons must identify and treat the presence of an urge component before surgery.
Conversely, poor detrusor function is a relative contraindication to sling surgery because the potential for urinary retention is increased. Women with absent or poor detrusor function in the presence of SUI are at a higher risk of experiencing prolonged postoperative urinary retention.
As a rule, for sling procedures, the patient must be completely anesthetized. The tension-free vaginal tape (TVT) procedure may be performed with either local or general anesthesia.
Surgeons currently use a number of materials for constructing pubovaginal slings: autologous tissues, allogenic grafts, and synthetic biomaterials. Synthetic slings may be fashioned from polypropylene, Gore-Tex, Marlex, Mersilene, or MycroMesh Plus. For treating intrinsic sphincter deficiency (ISD), the long-term success rates of the synthetic slings are higher than 85%. The long-term cure rates of cadaver tissue are not as good as was once hoped.
Serious complications from sling surgery may occur. However, urethral obstruction is a potential complication with all sling surgeries. The incidence of sling infection and erosion is higher when using synthetic materials. The potential complications must be weighed against the durable cure rates of synthetic slings and complication profiles of fascia slings (autologous).
The ideal sling material that produces consistently lasting results and minimizes morbidity remains elusive. In theory, the ideal sling material should last the lifetime of the patient. Researchers hope that advances in surgical techniques, biomechanical engineering, and design will produce the ideal sling material in the future.
Autologous tissue used for sling procedures include rectus fascia, fascia lata, and the anterior vaginal wall. Surgeons harvest autologous sling materials at the time of sling surgery. If a standard pubovaginal sling procedure is performed, harvest a 10 cm by 2 cm piece of tissue.
Allogenic grafts include cadaveric fascia lata and rectus fascia that have been processed by freeze-drying, gamma irradiation, or solvent dehydration. These tissues are harvested from cadaver donors and must be rehydrated at the time of sling surgery.
The advantages of allografts include shorter operating time and decreased morbidity. The disadvantages include the risk of bacterial infection and the possibility of transmitting intact genetic material to the recipient. Recently, the use of some cadaver allografts has been criticized for early degradation resulting in recurrent stress urinary incontinence (SUI) and accordingly is used less commonly now.
The benefits of synthetic materials are decreased operating time, less morbidity (ie, no need for large suprapubic incision), and the potential for better long-term durability. Potential risks of synthetic slings include vaginal and urethral tissue erosion.  Polypropylene tension-free synthetic slings appear to be the best-studied approach for the treatment of SUI. Consequently, most sling procedures performed today entail the use of some form of tension-free synthetic polypropylene sling.
For rectus fascia pubovaginal and suburethral sling procedures, vaginal wall suburethral sling procedures, and tension-free vaginal tape (TVT) procedures, place the patient in the dorsal lithotomy position.
For fascia lata pubovaginal and suburethral sling procedures, position the patient on her side with 1 leg slightly flexed.
All patients should have preoperative sterile urine culture. Administer broad-spectrum intravenous (IV) antibiotics 1 hour before skin incision. Identify any coexisting vaginal prolapse before surgery so that vaginal reconstruction may be performed simultaneously.
Counseling should address potential risks and complications (eg, bleeding, infection, persistent SUI, de novo urge incontinence, worsening urge incontinence, urinary retention). Complications unique to synthetic slings are sling infection, vaginal tissue erosion, and urethral transection and bladder injury. All patients undergoing pubovaginal sling surgery should be informed of the possible need for postoperative self-catheterization and short- and longer-term voiding dysfunction.
Performing a proper sling procedure requires adherence to certain fundamental principles. The 5 basic principles are as follows:
The sling is only as strong as its weakest link.
Sling size does matter.
Force vectors are important.
Slings should be tension-free (see the images below).
Slings should be biocompatible.Diagram shows 6-point fixation technique that allows even, lateral dispersion of force vectors on implanted sling. Edges of sling proper are affixed to underlying pubourethral fascia to prevent folding over or migration. When force vectors are lateralized rather than directed anteriorly toward pubis, tendency to pull up on sling to cause urethral obstruction is reduced.When weight-adjusted spacing nomogram is used for women with normal body weight, tie sling sutures over shod-covered hemostats by leaving 2-mm gap between hemostat and rectus fascia. For women who are obese, increase this gap incrementally according to amount by which they exceed ideal body weight (eg, 2-mm gap/25 lb). When using this method, tie suspension sutures looser for women who are obese.Weight-adjusted spacing nomogram. To tie suspension sutures on abdominal side, gauge tension on suspension sutures in inverse proportion to the patient's body weight. Before tying suspension sutures, clamp sutures with shod-covered hemostats to prevent inadvertent pulling up of sutures.
The weakest link of any sling may be the graft material, the suspension suture, or the origin or insertion site of the suspension sutures. Usually, the weakest link in an autograft or cadaver allograft is the sling edge where the suspension suture has been sutured in place. Suture pull-through at the sling edge is more common with autologous or cadaver patch slings.
Sling sizes in use today include classic pubovaginal slings, hemislings, and patch slings. The authors define a pubovaginal sling as a long strip of supporting material (ie, 2 cm by 14 cm) that spans from one edge of the rectus abdominis to the other. A hemisling is defined as a sling with a shorter strip of supporting material (ie, 2 cm by 7 cm) hung by suspension sutures. A patch sling is defined as a sling with a short graft (ie, 2 cm by 4 cm) hung by suspension sutures.
The success of a pubovaginal sling is predicated on its becoming completely engrafted or scarred in the retropubic space as the tissue remodels postoperatively. If the graft material simply disappears and engraftment or scarring does not take place, recurrent stress urinary incontinence (SUI) may develop.
A critical element is tying the suspension sutures to ensure continence without obstruction. Techniques that have been used include the following:
Vaginal packing, developed by Nichols in 1973
Spacer size of forefinger, developed by Benderev in 1994
Cystoscope at 30°, developed by Raz in 1997
Two fingers under the sutures, developed by McGuire in 1998
Transvaginal ultrasonography, developed by Yamada in 1998
Tension-free vaginal tape (TVT), developed by Ulmsten in 1999 
The biocompatibility of the sling material with the host is best when autologous tissues are used. Vaginal and urethral erosions resulting from unfavorable interaction between synthetic slings and the host tissue are well documented.
Some synthetics seem to be more predisposed to tissue rejections than others. Polyester meshes have relatively rigid and rough surfaces that cause intense inflammatory responses, with a 27% erosion rate. On the other hand, polypropylene mesh slings appear to have lower erosion rates (0-3%) than other synthetics. The meshlike matrix of the sling allows polypropylene to become incorporated into the host tissue, with minimal bacterial colonization and decreased erosion.
On July 13, 2011, the FDA issued a statement that serious complications are not rare with the use of surgical mesh in transvaginal repair of pelvic organ prolapse. The FDA reviewed the literature from 1996-2011 to evaluate safety and effectiveness and found surgical mesh in the transvaginal repair of pelvic organ prolapse does not improve symptoms or quality of life more than nonmesh repair. The review found that the most common complication was erosion of the mesh through the vagina, which can take multiple surgeries to repair and can be debilitating in some women. Mesh contraction was also reported, which causes vaginal shortening, tightening, and pain.
The FDA’s update states, “Both mesh erosion and mesh contraction may lead to severe pelvic pain, painful sexual intercourse or an inability to engage in sexual intercourse. Also, men may experience irritation and pain to the penis during sexual intercourse when the mesh is exposed in mesh erosion.” The FDA is continuing to review the literature regarding surgical mesh in the treatment of stress urinary incontinence and will issue a report at a later date. See the full update regarding surgical mesh in pelvic organ prolapse here: FDA Safety Communication: Update on Serious Complications Associated with Transvaginal Placement of Surgical Mesh for Pelvic Organ Prolapse.
The biocompatibility of cadaver allografts with the host has been variable. Whereas some authors have reported excellent early cure rates, others have reported poor results with cadaver fascia lata.  The lack of a durable cure is theorized to be due to early degradation of the cadaver allograft within the implanted host tissue. Whether this degradation is related to differences in tissue processing remains unclear at this time.
Rectus Fascia Pubovaginal Sling
The rectus fascia pubovaginal sling procedure is performed through the vagina and through a suprapubic incision above the pubic bone. After the patient is completely anesthetized, place her in a dorsal lithotomy position. Using sterile technique, prepare and drape the vagina, perineum, and suprapubic areas. Place a Foley catheter in the bladder.
Make a transverse lower abdominal incision (Pfannenstiel) over the suprapubic area. Harvest a long ribbon of rectus fascia (eg, 10 cm by 2 cm) from the lower abdomen.
Next, make a trapdoor incision on the anterior vaginal wall. Dissect the vaginal wall flap off the urethra to expose the bladder neck. Center the white fascial ribbon at the bladder neck. Bring up both ends of the rectus sling to the lower abdominal wall, and affix both ends of the sling to the abdominal fascia on either side (see the image below). The bladder neck now is nestled in the middle of the sling. Adjust the tension on the sling to provide adequate compression and coaptation of the bladder neck.
Pull up the vaginal wall flap to cover the sling in its entirety. Close the vaginal and abdominal incisions with absorbable sutures. Place a small suprapubic tube. Inspect the quality of the operation using cystoscopy (see the image below). At the end of the operation, place antibiotic-soaked vaginal packing. Routinely, the packing is removed the morning after the operation.
Potential complications include injury to the urethra, bladder, or ureters during the dissection. Bowel injury may occur during the insertion of the suprapubic tube; however, this injury is rare. Abdominal hernia formation is another potential risk.
If the sling is oversuspended or if excessive scarring occurs, delayed voiding or urethral obstruction may develop. New-onset urge incontinence occurs in 15-20% of individuals and necessitates anticholinergic therapy. Temporary urinary retention, necessitating self-intermittent catheterization, is rare (approximately 5%) but may occur following surgery.
Studies show an incidence rate of 3% for urethral obstruction by the sling. Chronic urinary retention from urethral obstruction may be corrected by urethrolysis or treated with lifelong intermittent catheterization.
Fascia Lata Pubovaginal Sling
The fascia lata pubovaginal sling procedure is performed via a combined thigh-abdominal-vaginal approach for this operation. After satisfactory induction of general anesthesia, position the patient on her side with 1 leg slightly flexed. Next, prepare and drape the outer thigh using sterile technique.
Initially, make a single 5-cm skin incision on the outer thigh. Using a special stripper, create an extended transverse thigh fascial flap. Harvest a long ribbon of strong glistening white fascia lata (eg, 10 cm by 2 cm). Place a small Penrose drain in the incision, and close the thigh wound.
Reposition the patient in the dorsal lithotomy position. Using sterile technique, prepare and drape the vagina, perineum, and suprapubic areas. Place a Foley catheter in the bladder.
Next, make a transverse incision over the suprapubic area. Then, make a small vertical incision on the anterior vaginal wall. Position the fascia lata sling underneath the bladder neck, and pass both ends of the sling up to either side of the abdominal wall. Sew the 2 ends of the fascia lata sling onto the abdominal wall. The bladder neck rests on the center of the sling.
Close the vaginal and the abdominal incisions. Place a small suprapubic tube. Check the quality of the operation using cystoscopy. At the end of the operation, place antibiotic-soaked vaginal packing that will be removed the following morning.
Potential complications specific to this operation are urethral or bladder perforation during the dissection of the bladder neck. In addition, postoperative leg pain may persist temporarily. Chronic leg pain has not been reported. The incidence of new-onset urge incontinence is approximately 7-9%.
The most serious drawback of the fascia lata sling is delayed voiding. Urinary retention occurs when the sling is pulled up too tightly or with the development of excessive fibrosis. The incidence of urinary retention is as high as 30% with this operation. If the sling is pulled up too tightly, the risk of permanent urinary retention approaches 100%. However, the urinary retention is often temporary, and successful resolution may occur up to 3 months after the surgery.
During the waiting period, the patient should perform clean intermittent catheterization. A resolution of urinary retention manifests by spontaneous voiding between catheterizations.
Urethral obstruction reportedly occurs in approximately 6% of patients undergoing this operation. If urinary retention persists 3 months after surgery, a simple transection of the sling (urethrolysis) should allow normal voiding. As an alternative to urethrolysis, some surgeons advocate lifelong self-catheterization.
Rectus Fascia Suburethral Sling
The rectus fascia suburethral sling procedure is performed through the vagina and through a lower abdominal incision above the suprapubic area. After anesthetizing, place the patient in the dorsal lithotomy position. Prepare and drape the vagina, perineum, and suprapubic area using sterile technique. Place a Foley catheter in the bladder.
Initially, make a short transverse suprapubic incision in the lower abdomen. Retrieve a small rectangular piece of rectus fascia (eg, 3 cm by 4 cm) from the suprapubic area. Anchor the 4 corners of the rectangular fascia with permanent nonabsorbable sutures.
Next, make a trapdoor incision on the anterior vaginal wall. Dissect the vaginal flap off the urethra to expose the bladder neck. Position the suburethral patch sling under the bladder neck. Then, transfer the suspension sutures from the vaginal side to the abdominal side, where they are tied securely (see the image below).
Close the vaginal and abdominal incisions. Place a small suprapubic tube, and perform cystoscopy. At the end of the operation, place antibiotic-soaked vaginal packing. Routinely, the packing is removed the morning after the operation.
Potential complications include injury to the urethra, bladder, or ureters during the dissection and during transfer of the suspension sutures. Bowel injury may occur during the insertion of the suprapubic tube. If the surgeon ties the sutures under tension, the risk of urethral obstruction may be significant. Temporary urinary retention reportedly occurs in approximately 18% of women.
Failure of the sling to cure incontinence can occur as a result of insufficient support of the bladder neck by the sling or secondary to an overactive bladder. New-onset urge incontinence develops in 15-20% of the cases. Chronic urinary retention, requiring lifelong self-intermittent catheterization, is rare but may occur after surgery.
Fascia Lata Suburethral Sling
The fascia lata suburethral sling procedure is performed via a combined thigh-abdominal-vaginal approach. After inducing anesthesia, position the patient on her side with 1 leg slightly flexed. Next, prepare and drape the outer thigh using sterile technique.
Make a single short incision on the outer thigh, and create a small thigh fascial flap. Harvest a white rectangular piece of fascia lata (eg, 3 cm by 4 cm), and close the thigh incision.
Then, reposition the patient in the lithotomy position. Prepare and drape the vagina, perineum, and suprapubic area using sterile technique. Place a Foley catheter in the bladder.
Next, make a small 5-cm suprapubic incision in the lower abdomen. Affix nonabsorbable suspension sutures to the 4 corners of the rectangle. Make a trapdoor incision on the anterior vaginal wall. Dissect the vaginal wall off the urethra to expose the bladder neck. Position the fascia lata patch sling at the bladder neck. Then, transfer the suspension sutures from the vaginal side to the abdominal side, and securely tie over the lower abdomen.
Close the vaginal flap to cover up the sling. Reapproximate the vaginal and abdominal incisions with absorbable sutures. Place a small suprapubic tube. Check the quality of the operation using cystoscopy. At the end of the operation, place antibiotic-soaked vaginal packing. Remove the packing the next morning.
Potential complications include injury to the urethra, bladder, or ureters during the dissection and during the transfer of the suspension sutures. Bowel injury may occur during the insertion of the suprapubic tube. If the surgeon ties the sutures under tension, the risk of urethral obstruction may be significant.
Failure of the sling to cure incontinence can result from insufficient support of the bladder neck by the sling or can occur secondary to an overactive. New-onset urge incontinence develops in 15-20% of the cases. Chronic urinary retention, necessitating lifelong self-intermittent catheterization, is rare but may occur after surgery.
Vaginal Wall Suburethral Sling
The vaginal wall suburethral sling procedure is performed through the vagina and through a small incision in the lower abdomen. After anesthetizing, place the patient in the lithotomy position. Prepare and drape the vagina, perineum, and suprapubic area using sterile technique. Place a Foley catheter in the bladder.
Initially, circumscribe an A-shaped incision within the vagina. Harvest a rectangular island of vaginal tissue, and create a proximal vaginal wall flap. Tailor the size of the vaginal island to the length and width of the urethra (eg, 1.5 cm by 3.5 cm). Anchor the 4 corners of the rectangular island of vaginal wall with nonabsorbable suspension sutures.
Next, make a transverse suprapubic incision. The suspension sutures pass from the vaginal side to the suprapubic side. Advance the proximal vaginal wall flap to cover up the sling and to restore the integrity of the vagina. Tie the suspension sutures over the lower abdomen (see the image below).
Close the vaginal and abdominal incisions, and place a small suprapubic tube. Examine the quality of the operation using cystoscopy. At the end of the operation, place antibiotic-soaked vaginal packing. The packing is removed the morning after the operation.
Potential complications at the time of the operation are bleeding, urethra or bladder perforation during the dissection, and ureter obstruction by the suspension sutures. One complication unique to this surgery is vaginal cyst formation; however, this is uncommon.
Any sling technique involves a risk of delayed voiding, obstructive urinary symptoms, and even permanent urinary retention. After vaginal sling surgery, approximately 1-5% of women need long-term intermittent self-catheterization for chronic urinary retention. Of the women undergoing this operation, 33% experienced resolution of preexisting urge incontinence. New-onset urge incontinence reportedly occurs in 15-43% of the cases; this usually responds to anticholinergic medication. Vaginal shortening has not been reported.
Gore-Tex patch sling
Gore-Tex is a white soft synthetic biomaterial that surgeons use widely, from general to cardiovascular surgery. [16, 17, 18] In the past, surgeons used a long strap of Gore-Tex as a pubovaginal sling for recurrent SUI when the individual’s native tissues were in short supply or of poor quality. A beltlike strap of Gore-Tex was wrapped around the bladder neck to compress and increase the urethral resistance (see the image below).
Although the continence rates were quite good, this technique fell out of favor because of a high rate of sling complications. Researchers observed that when Gore-Tex was used as a long strap, the incidence of bacterial infection was significant, necessitating removal of the sling in 23% of patients. However, when Gore-Tex was used as a short patch (eg, the size of a small postage stamp), the risk of infection and erosion remained low (3%, while the continence rate remained excellent.
The Gore-Tex patch sling compresses the bladder neck and restores the necessary urethral resistance to prevent involuntary SUI. This procedure is not performed commonly now and is described here more for historical purposes.
The potential complications specific to this operation include bleeding that requires blood transfusion; separation of the vaginal incision, thus exposing the sling; and urinary retention. The reported incidence of vaginal wall erosion with an exposed sling is 3%. Urethral or bladder erosion has not been reported but is a potential risk. If sling erosion occurs, the Gore-Tex material is easy to remove.
Failure of the Gore-Tex patch sling to cure incontinence can result from inadequate suspension of the sling or secondary to bladder hyperactivity and urge incontinence. New-onset urge incontinence occurs in 32% of women. Chronic urinary retention, requiring incision of the sling, is rare (3%) but may occur following surgery. Chronic retention is corrected easily by incising the sling.
If urethral obstruction occurs from oversuspension of the sling, the Gore-Tex sling is easy to correct because the sling is easily identified and incised.
Tension-Free Vaginal Tape
The TVT sling procedure is performed through the vagina, with 2 small lower abdominal incisions above the pubic bone. It may be done with either local or general anesthesia.
Place the patient in the dorsal lithotomy position. Prepare and drape the vagina, perineum, and suprapubic area using sterile technique. Place an 18F Foley catheter in the bladder.
If local anesthesia is used, apply the local anesthetic to the skin just above the pubic tubercle on both sides of the midline. Continue the application of the anesthetic on each side, through the rectus fascia, the rectus abdominis muscles, and into the space of Retzius.
Apply local anesthetic to the anterior vaginal wall. Make a small vertical incision on the anterior vaginal wall at the mid urethra. Tease the vaginal wall tissue off the urethra to expose the mid urethra, and dissect paraurethrally toward the endopelvic fascia.
Insert the rigid catheter guide (see the image below) into the Foley catheter. Have an assistant pivot the handle of the guide to the surgeon’s left to expose the patient’s left endopelvic fascia. Puncture the patient’s left endopelvic fascia with the TVT needle, and advance the needle through the space of Retzius and to the anterior abdominal wall. The needle must hug the posterior wall of pubic symphysis during this maneuver. Tent up the abdominal skin with the needle. Incise the skin over the needle, and allow the needle to emerge.
Fill the bladder with 250 mL saline. Perform cystoscopy with the needle in situ to rule out bladder and urethral injury. Empty the bladder. Advance the needle and the tape above the abdominal wall. Leave the needle in the abdomen.
Repeat the same procedure on the contralateral side. Make sure the tape does not twist during the insertion. Cut the tape at both abdominal ends, and remove the needles; however, leave the plastic sheath in place.
Note that the success of this operation is predicated upon performing a proper tension test. Although this device is marketed as tension-free, the surgeon must carry out the test to make sure that it is so. The manufacturer recommends performing the tension test by filling the bladder with 250 mL of saline and having the patient cough. The tape should be pulled upward on both sides until only a few drops leak out when the patient coughs.
Remove the plastic sheath from the tape, and close the vaginal and abdominal incisions.
Complications, including sling erosion (into either the vagina or bladder/urethra),  suprapubic abscesses, and urethral sloughing, are rare.  However, as with any other sling procedures, the risk of urinary retention still exists. Urethral obstruction secondary to TVT should be treated aggressively with urethrolysis (sling incision) within the first 3-6 weeks because the likelihood of spontaneous voiding without urethrolysis is rare. This must be a joint decision between patient and physician. The same applies for other synthetic mid-urethral slings placed in an antegrade fashion.
Transobturator Tape Sling
The transobturator tape (TOT) sling procedure is similar to the TVT procedure; however, the needle passers are placed in the medial portion of the obturator canal inside the groin creases at the level of the clitoris laterally. Tensioning is performed in much the same way as with TVT, and the sling is placed in a tension-free manner (see the image below). Care should be taken to keep from "buttonholing" the lateral aspect of the vagina at the level of the vaginal fornices.
Immediate Postoperative Care
After surgery, administer intravenous (IV) antibiotics for 24 hours or less. On the following morning, remove vaginal packing and IV lines. Also, remove the dressing over the incision. Discharge patients from the hospital with pain medications 1-3 days after surgery.
If suprapubic tubes are placed, instruct patients to check postvoid residual volumes via the suprapubic catheter. Remove the suprapubic catheter when patients are able to void spontaneously; this may be as early as a day after surgery or may take as long as 3 weeks. If patients still are experiencing retention at 3 weeks, remove the suprapubic tube and teach the patient self-intermittent catheterization.
Most patients undergoing mid-urethral tension-free sling procedures can be discharged without a catheter because most void in the recovery area.
Autologous urethral sling procedures have an approximately 70-95% overall long-term cure rate. Recent outcome analysis reveals that the lasting cure rate may be less than previously reported. 
For the rectus fascia pubovaginal sling, available medical literature reports a postoperative continence rate of 81-95% after 4 years, although a minimum of randomized trials exist for this procedure. For more than 10 years, many surgeons have successfully used this operation for treatment of intrinsic sphincter deficiency (ISD).
For the fascia latapubovaginal sling, long-term (>4 y) data show a 78-92% postoperative continence rate with this operation. Continence surgeons used this procedure for more than 22 years, with excellent results for complicated and simple stress urinary incontinence (SUI). Still, one must realize most data points with this and most rectus fascia series involve single-center, single-surgeon experiences with studies that include many dropouts not accounted for (completer analysis)
For the rectus fascia suburethral sling, the long-term postoperative continence rate 80-82% after 4 years. Some surgeons prefer this patch-sling operation to the long pubovaginal sling because of the reduced morbidity and the faster recuperative period.
For the fascia latasuburethral sling, the available medical literature reports an 80-92% lasting cure rate for more than 4 years. Some surgeons prefer this short suburethral sling to the long pubovaginal sling because of the reduced morbidity and the faster recuperative period.
For the vaginal wall suburethral sling, postoperative continence rates are 70-94% at a mean follow-up of 2 years. Long-term data for more than 4 years are not yet available. This sling operation does not require secondary harvesting of the abdomen or thigh; however, this surgery is no longer favored for the treatment of type III SUI. [22, 23]
For the Gore-Tex patch sling, the available medical literature reports a postoperative continence rate of 88% at a mean follow-up of 4.2 years. Surgeons have used this operation for more than 7 years. Women undergoing this operation have reported a high level of satisfaction with their experience.
For the tension-free vaginal tape (TVT) procedure, the long-term cure rate is 84% at a mean follow-up of over 10 years. Reich et al found an objective cure rate of 89.8% at a mean follow-up of more than 7 years.  The subjective cure rate was 82.4%; stress urinary incontinence improved in 13%, was unchanged in 2.8%, and worsened in 1.8% of patients.
Five years of follow-up data show that transobturator tape (TOT) procedures have good durability, and short-term studies have confirmed noninferiority to TVT procedures.  However, Schierlitz et al found that retropubic TVT was more effective than TOT sling in women with urodynamic SUI and ISD. 
Serious complications from sling surgery are uncommon. However, urethral obstruction may occur with any sling surgery. Urethral obstruction occurs because the surgeon tied the sling too tightly. The degree of obstruction reflects the patient’s voiding symptoms. Complete obstruction results in urinary retention, whereas partial obstruction manifests with voiding symptoms (eg, hesitancy, straining, urgency, urge incontinence).
Bleeding during transvaginal sling surgery is often troublesome and may be challenging to correct. Bleeding invariably occurs when the surgeon punctures the endopelvic fascia to facilitate the passage of suspension sutures. The technique of puncturing the endopelvic fascia is performed by many surgeons blindly under digital guidance. If one is not careful, heavy bleeding may ensue.
To prevent transvaginal hemorrhage, the authors advocate dissecting the anterior vaginal wall off the endopelvic fascia under direct vision. The plexus of veins is located at the 10- and 2-o’clock positions at the level of the bladder neck. Thus, proper anatomic dissection under direct vision allows preservation and avoidance of these veins when the endopelvic fascia is punctured. If one is concerned that these veins may become lacerated, these veins may be ligated prophylactically using 4-0 polyglactin in a figure-eight fashion.
If heavy bleeding is encountered, application of direct pressure the anterior vaginal wall slows down the bleeding and gives the surgeon more time to obtain better exposure. Then, one may suture-ligate the offending vessel under direct vision. These vessels are always located at the edges of the endopelvic fascia. Then, the sling is placed quickly, and the suspension sutures are tied.
The authors do not advocate packing the space of Retzius through the hole in the endopelvic fascia, because this may worsen the bleeding. Furthermore, stopping the bleeding
suprapubically is not necessary because the offending vessel is never identified.
An important complication that may occur with any sling surgery is urethral obstruction. [27, 28] Urethral obstruction occurs because the sling has been tied too tightly. The degree of obstruction reflects the patients’ voiding symptoms. Complete obstruction results in urinary retention, whereas partial obstruction manifests with voiding symptoms, including hesitancy, straining, urgency, and urge incontinence.
Methods to prevent urethral obstruction include placing 2 fingers under the suspension sutures when biological bladder neck slings are created, using a spacer, placing vaginal packing, angling a cystoscope at 30°, and using transvaginal ultrasonography to assess the proper urethrovesical angle as the suspension sutures are tied.
In spite of all of these precautions, the risk of urethral obstruction still exists, and the experience of the surgeon determines whether obstruction occurs. TVT synthetic procedures usually require some small amount of space between the sling and urethra and assurance that the sling will not spring up when placed.
Stress urinary incontinence
Approximately 5-10% of patients have recurrent or persistent SUI after sling surgery. Reasons for failure include (1) suture pull-through from the edge of the sling, (2) early degradation of sling material, (3) improper placement of the sling, and (4) making the sling too loose.
Suture pull-through from the sling edge is more common with autologous and cadaver tissues, whereas early degradation of sling material is isolated to cadaver allografts. Both of these conditions result in loss of either anatomic support or adequate resting urethral closure pressure. If the sling is placed too proximally (eg, bladder) or too loosely, inadequate resistance to the proximal urethra develops.
If the sling is too loose, some authors recommend suprapubic sling revision before resorting to complete sling reconstruction. A suprapubic sling revision is performed with the patient in the dorsolithotomy position. A suprapubic incision is made, and the suspension sutures are dissected out. Ipsilateral suspension sutures are pulled up.
The cotton swab test and the bladder leak test are performed. The cotton swab should be at zero degrees with respect to the floor, and the bladder should leak moderately when filled with 500 mL of water. The suspension sutures are affixed to the rectus fascia on the contralateral side, and the incision is closed.
New-onset urge incontinence or worsening urge incontinence is a potential complication of any sling surgery. Approximately 10-30% of patients may manifest de novo urge symptoms, whereas 50-60% may experience resolution or improvement of preoperative urge incontinence.
De novo urge incontinence usually is temporary and many times resolves over several weeks. Persistent urge incontinence may be treated successfully with pelvic floor exercises and bladder-relaxing medications, alone or in combination. De novo urge symptoms and frequency may be a sign of bladder outlet obstruction, even without high postvoid residual volumes and the surgeon must be aware of this happening.
Women who undergo surgery to construct a sling are at a significant risk of urinary retention. Although temporary in most cases, urinary retention may last a month or more. Permanent urinary retention may occur after 2-30% of pubovaginal sling surgeries.
While the condition persists, institute self-catheterization. As an alternative to catheterization, take down the surgery either by cutting the suspension suture or by freeing up the sling (ie, urethrolysis  ). Successful urethrolysis allows spontaneous voiding in 77-85% of women with urinary retention. To prevent recurrence of SUI after surgery, some surgeons perform the operation again at the time of urethrolysis, although this is not advised.
Complications specifically associated with the use of autologous, cadaver, and synthetic slings include sling infection and tissue erosion. The incidence of sling infection and erosion is higher when a synthetic biomaterial is used. Bowel perforation is a unique complication of TVT surgery. Specialists have detected intact DNA material in commercially processed cadaver allografts. Whether these genes are truly infectious remains unknown. Proper informed consent must be obtained when cadaver allografts are used.
Methods for avoiding sling erosion include the following:
Maximize the surgical exposure, and operate under direct vision. (The authors use a headlight and a self-retaining Lone-Star retractor.)
Employ meticulous surgical technique, and handle tissues gently.
Dissect in a nice avascular anatomic plane between the pubocervical fascia and the anterior vaginal wall to create thick anterior vaginal wall flaps, and use smaller midline incisions.
Make sure the sling is unfurled completely, using the 6-point fixation technique.
Tie the suspension sutures loosely enough to prevent obstruction, yet snugly enough to cure the incontinence. (The authors use the weight-adjusted spacing nomogram.)
Vaginal erosion associated with woven polyester slings treated with pressure-injected bovine collagen and Gore-Tex is treated with simple excision of the sling.
The patient is placed in the dorsal lithotomy position under general anesthesia. Vaginal inspection reveals the exposed sling. Often, the sling material is protruding through the vaginal incision. The sling material is either dissected out or simply pulled down with an Allis clamp, and the body of the sling is excised, leaving the suspension sutures intact. The vaginal wall is irrigated with antibiotic solution and closed.
As an alternative to formal excision and removal, a more conservative revision may be applied to polyethylene terephthalate (Mersilene) slings.  Surgical revision consists of trimming the exposed mesh as needed, excision of granulation tissue, and re-covering of the erosion in 2 layers.
For urethral erosions, the sling may be excised transvaginally, transurethrally, or both in combination. Then, the urethra is reconstructed by using a Martius labial fat pad graft as necessary. The vaginal wall is irrigated with antibiotic solution and closed.
Bowel perforation is a unique complication of TVT surgery and should not occur with other sling procedures.  Intact DNA material has been detected in commercially processed cadaver allografts. Whether these genes truly are infectious remains unknown. Proper informed consent must be obtained when cadaver allografts are used.
Patients return to the clinic for follow-up after surgery for removal of the catheter if it is left in place. Otherwise, the patient returns later if the catheter was removed in the recovery room.