Expert Panel Presentation:
Urinary Retention Following Midurethral Tapes
Overactive Bladder (OAB)
By Kristin Jenkins
Quebec City, Que. Obstruction after sling procedures is not rare and the incidence is probably underestimated, Dr. J. Christian Winters told delegates to Urogynecology Quebec 2007.
Patients with refractory LUTSdespite normal PVR may be obstructed, said Dr. Winters, who is professor and chairman, Louisiana State University Health Sciences Center, New Orleans, LA. Transvaginal sling incision can be successful at relieving symptoms, however there is some risk of recurrent SUI, he said. Urethrolysis, he added, is rarely indicated.
“There is a huge amount of underreporting of complications [with sling procedures],” said Dr. Winters. Complications associated with mid-urethral slings include everything from transient voiding dysfunction, hematoma formation, bladder perforation (5%) and vaginal extrusion of tape to major complications such as tape erosion in the urethra or bladder, vascular injury and/or neuropathy, bowel injury and urinary retention in 2-3%.
The most common cause of retention following a mid-urethral tape is excessive tension placed at the time the sling is secured. “It’s not just retention, it’s also obstruction,” pointed out Dr. Winters. Talk to the patient, he advised, and find out when symptoms first appeared. “The history is the most important. Ask the patient, ‘Did symptoms occur at the time of the sling?’ ”
Talking to the patient may be more effective than urodynamics at determining the cause of obstruction, pointed out Dr. Winters. “There is no normative data,” he said, “and there are a number of authors who suggest that this doesn’t correlate.”
Timing of intervention is also crucial. “If you wait too long and storage problems develop,” said Dr. Winters, “they may not go away.”
The best approach is to go back in and loosen the tape within days of surgery. “It’s better to loosen the tape within the week rather than going in later and transsecting it,” said Dr. Winters. “This just opens the door to recurrence.” Make sure you know where the sling is before you try to adjust it, he added.
Although the most common complications seen with midurethral tapes are bladder perforation and voiding dysfunction, “we must also consider and be able to treat sling erosions and post-operative infections,” said Dr. Vincent Lucente, medical director of the Institute for Female Pelvic Medicine & Reconstructive Surgery, New Orleans. “Infections and erosions are extremely debilitating,” noted Dr. Lucente. In addition, “A lot of voiding dysfunction is ‘under the radar,’” he said.
The reported incidence of UTIs is 4.1% while the incidence of bladder and urethral erosions is 5/90,000 and 6/90,000 respectively. The true incidence of vaginal erosion/exposure and delayed bowel erosion remains unknown.
Vaginal erosion can be prevented by avoiding superficial placement of tape under the mucosa, said Dr. Lucente. “Use plenty of local anesthetic/fluid at mid-urethra and for periurethral dissection,” he advised, adding that it’s best to use synthetic materials specifically designed for suburethral placement. For intervention, consider local excision of the mesh and if the erosion is small, estrogen cream.
To prevent urethral erosion, avoid excessive suburethral dissection and don’t place the tape under tension. For a retropubic approach, use a catheter guide and a Foley. Should urethral erosion occur, the strategy should be local excision of mesh, layered closure of the urethra and an indwelling urethral catheter for several days.
To prevent injury to the bowel, you need to place the TVT-R close to the pubic symphysis, said Dr. Lucente. In the event of delayed bowel injury, particularly if the mucosa is compromised, it may be necessary to resect the bowel. Otherwise, the approach should be dissection and oversewing of the serosal defect.
Although wound infections are rare, consider the use of pre-operative antibiotics, such as Ancef 1 gm IV or Gent/Clinda 80 mg/600 mg IV or Vancomycin 1 gm. For post-op infection, said Dr. Lucente, “consider outpatient antibiotic treatment PO versus inpatient IV.”
Following a mid-urethral sling, be prepared for a difference of opinion with your patient as to what constitutes a satisfactory post-operative outcome, warned Dr. Roger Dmochowski, professor in the department of urologic surgery, Vanderbilt University Medical Center, Nashville, TN. Dr. Dmochowski is also director of the Vanderbilt Continence Center.
“The definition of failure is ‘all over the map,’ ” he told delegates. “In a patient’s eyes, “failure may be seen as any leakage at all, whereas in a surgeon’s eyes, success may be only 1-2 pads a day.”
The best way to eliminate major vascular and bowel injury and to minimize erosion into the bladder is to avoid the retropubic space, said Dr. Dmochowski.
In discussing overactive bladder (OAB) following a mid-urethral sling, Dr. Geoffrey Cundiff asked, “Do mid-urethral slings cure or cause OAB?”
“OAB is really a reflection of voiding obstruction,” concluded Dr. Cundiff. In patients with de novo OAB following a mid-urethral sling and normal PVR, treatment should include bladder re-training and the use of anticholinergics. In patients with elevated PVR and either de novo OAB or persistent OAB, sling release is the way to go.
Similarly, in the patient with persistent OAB and normal PVR, consider the use of anticholinergics and/or Botox or sacral nerve stimulation, said Dr. Cundiff.