Vaginal, bladder or urethral extrusion usually presents after a few months of sling surgery but can occur after many years. The usual presentation of vaginal tape extrusion is either discomfort, pain, dyspareunia, partner dyspareunia (hispareunia) or vaginal discharge, but some of these patients can be asymptomatic. Meta-analysis has shown that vaginal extrusion of tape appears to be increased with the transobturator approach [21, 23] and is more likely to occur at the lateral vaginal sulci. The horizontal orientation of the needle passage with TOT possibly predisposes to it. Possible reasons for vaginal extrusion include incomplete closure of vaginal incision, wound infection or excessive foreign body reaction.

The management of vaginal extrusion can be conservative with observation only [29] or topical estrogen especially in the early postoperative period. If unsuccessful, surgical approach becomes necessary usually with vaginal excision or trimming of the exposed mesh, with closure of vaginal wall defect. This has been shown to be done successfully in the outpatient setting as well. If the mesh material is infected or the extrusion is recurrent, it becomes necessary to remove the entire sling.

Extrusion into the urinary tract- bladder or urethra is a potential complication with both types of sling approach. In patients who are diagnosed with sling extrusion into the urinary tract, most often it is the result of a missed perforation. Hence the importance of cystourethroscopy following sling surgery needs to be stressed.

Urethral sling extrusion can result from placement of the mesh deep in the periurethral fascia or from excessive tensioning of the sling. Patients can present with recurrent UTI, frequency and urgency, hematuria or decreased urinary stream. The management of urethral erosion involves removal of the sling and repair of the defect over a catheter, with re-approximation of periurethral fascia. Reinforcing the repair with a labial pad of fat can reduce the tension over the repair and promote healing. Indwelling catheter for a minimum of 2 weeks is recommended [30]. There are reports of successful management of urethral slings using endoscopic scissors or laser treatment [31].

Bladder extrusion of the tape can present with irritative bladder symptoms of frequency, urgency, urge incontinence, hematuria or lower abdominal pain. Patients with these symptoms not responding to conservative measures need cystoscopy to identify bladder extrusion. Surgical management of bladder extrusion can be done endoscopically, via cystoscope or laparoscope, or openly through a retropubic or vaginal approach. In extrusions into the bladder involving a large surface area, open excision may be preferred over endoscopic excision; however, the latter is becoming increasingly possible. Laparoscopy-assisted endoscopic excision is another option; indeed, it may be the preferred route. After excision, indwelling catheter for 2 weeks allows healing of the defect.

Patients with insidious voiding dysfunction following sling surgery can present with changes in voiding pattern such as hesitancy, poor stream, straining to void, sensation of incomplete emptying, and increased postvoid residual urine volume (PVR) or with development of de novo urgency symptoms. Klutke et al. noted a 2.8 % rate of obstructive symptoms that ultimately required transvaginal sling release in a series of 600 patients who underwent TVT [32]. Voiding dysfunction with the retropubic approach is around 3.4 % and with transobturator approach is 2.0 % in the TOMUS trial [33]. The increased incidence of voiding dysfunction in the TVT group is to be expected, as a sling inserted in this manner has a propensity to cause more obstruction than a sling inserted via the transobturator approach, reflecting the vector of pull. Evaluating the risk factors for voiding dysfunction after sling surgery, the study also showed that concomitant surgery does not increase the risk.

Preoperative urodynamic variables have been evaluated to assess their predictive value in postoperative voiding dysfunction. Some studies have shown that low preoperative peak flow rate, abnormal uroflow pattern or increased PVR can be predictive of postoperative voiding problem [34, 35]. On the other hand, some have stated that there are no preoperative urodynamic variables which can offer successful prediction [32, 36].

Evaluation in patients with post-op voiding dysfunction includes history of preoperative voiding patterns such as the use of Valsalva maneuver for emptying and other incontinence surgeries in the past. Pelvic examination should evaluate for urethral mobility and fecal impaction. Cystoscopy may be needed in ascertaining the symptom etiology.

Early intervention is required in women needing catheterization. The timing of intervention in other cases is determined by the degree of patient distress, time interval between the surgeries, and the onset of obstructive symptoms. In patients with predominant storage symptoms, the initial option would be behavioral modifications such as restriction of fluid intake, timed voiding and double voiding. Antimuscarinics and vaginal estrogen for irritative symptoms and alpha blockers for retention symptoms can be tried. Urethral dilatation has shown some benefit, but recent studies have shown dilatation to be ineffective and may predispose to urethral erosion [37].

Persistent symptoms may justify urodynamics to assess bladder outlet obstruction, but studies have shown it may not carry a good predictive value. In the presence of obstructive features and failure of conservative management, sling release is indicated. Surgical intervention for postoperative voiding dysfunction is needed in 1–2 % of patients and more commonly with retropubic slings [38]. Mobilization of the sling, division of the sling and a formal urethrolysis are the different surgical techniques used in sling release. Mobilization of the sling by loosening it is possible only in early interventions [39]. If this fails, the sling is divided either in the midline or laterally. A transvaginal midline sling division may appear simple, but the risk of urethral injury is high, since the sling is more commonly incorporated into the surrounding tissues in late interventions. With the catheter in place, a 2 cm longitudinal vaginal incision is made below the mid-urethra. The sling is identified by a combination of sharp and blunt dissection and with the help of a sound in the urethra. When the sound is withdrawn gradually with downward pressure, one can feel a “step-off” at the site of the sling. A right angle clamp is passed between the urethra and the sling, and the sling is incised in between the arms of the clamp. It is important to identify the sling, as scar tissue can be confused with the sling [40].

Lateral division of the sling can be helpful in avoiding urethral injury and the technique has been described by Long et al. [41]. The dissection is carried laterally towards the ischiopubic rami from the midline incision, sling is dissected away from the periurethral fascia and divided between two hemostats at 3 or 9 o’clock position. This leaves a “J”-shaped portion of the sling intact.

In a nationwide analysis by Laurikanien et al. [42], after a midline or lateral sling division, 49 % of patients were completely cured of retention. Using the lateral incision technique, Game et al. [43] quoted a 70 % continence rate after sling division. A formal urethrolysis involves dissection and entry into the retropubic space either via the abdominal or vaginal approach with resolution of voiding in 85 % of patients.

Urinary tract infection appears to be a common problem following sling surgery and recurrent UTI, defined as more than three episodes of UTI symptoms in a year, occurs in 2–4 %. A preoperative history of recurrent UTI, intra-op bladder perforation, occurrence of UTI within first 6 weeks of surgery, and a PVR >100 ml appear to be independent risk factors for recurrent UTI in the postoperative period [44]. In the TOMUS [33] trial, the risk of UTI was increased in those with concomitant surgery compared to those with mid-urethral sling alone. Postoperative recurrent UTI more significantly should alert the possibility of undiagnosed bladder or urethral tape extrusion and/or insidious voiding problem. Recurrent UTI is reported in 53 % of patients with obstructive feature. Identification and correction of the underlying problem are important in treating these patients.