Do not dilate or pull down on the sling with any kind of urethra dilator. The sling is more robust than the urethral mucosa, and we now appreciate that this practice is associated with urethral erosion.
If the problem is deemed to be excessive obstruction or over-resistance, and it is fewer than 10 days postop, the patient may be offered a minor revision; the original incision is reopened, the sling material is identified, and the sling arms (lateral to the urethra) are grasped with clamps. Gentle downward traction can loosen the sling.
The sling should be grasped laterally and not at the midpoint; some sling materials will stretch and fracture where the force is applied. A little bit of gentle downward traction (3-5 mm) will often give you the needed amount of space for relieving some of the obstruction.
Beyond 10 days postop, tissue in-growth makes such a sling adjustment difficult, if not impossible. At this point, I recommend transecting the entire sling in the midline.There is differing opinion about whether a portion of the mesh should be resected; I believe that such a resection is usually unnecessary, and that a simple midline release procedure is the best approach.
A study we performed more than a decade ago on surgical release of TVT showed that persistent post-TVT voiding dysfunction can be successfully managed with a simple midline release. Of 1,175 women who underwent TVT placement for stress urinary incontinence and/or intrinsic sphincter deficiency, 23 (1.9%) had persistent voiding dysfunction. All cases of impaired emptying were completely resolved with a release of the tape, and the majority remained cured in terms of their continence or went from “cured” to “improved” over baseline. Three patients (13%) had recurrence of stress incontinence (Obstet. Gynecol. 2002;100:898-902).
We used to wait longer before revising the sling out of fear of losing the entire benefit of the sling. As it turns out, a simple midline release (leaving most, if not all, of the mesh in place) is usually just enough to treat the new complaint while still providing enough lateral support so that the patient retains most or all of the continence achieved with the sling.
Complaints of de novo urge incontinence, or overactive bladder, should be taken seriously. Urge incontinence has even more significant associations with depression and poor quality of life than stress incontinence. In the absence of retention, usual first-line therapies for overactive bladder can be employed, including anticholinergic medications, behavioral therapies, and physical therapy. Failing these interventions, my assessment for this complaint will be similar to that for retention; I’ll look for evidence of too much resistance, such as difficulty in passing a catheter, a “speed bump” cystoscopically, or an elevated pDet on pressure-flow studies, for instance.
If any of these are present, I usually offer sling release first. If, on the other hand, there is no evidence of over resistance in a patient who has de novo urge incontinence or overactive bladder and is refractory to conservative measures, a trial of sacral neuromodulation or botox injections is considered the next step.
Erosion remains a difficult complication to understand. Long-term follow-up data show that it occurs after 3%-4% of sling placements, rather than 1% as originally believed. Data are inconsistent, but there probably is a slightly higher incidence of vaginal erosion with a transobturator sling, given more contact between the sling and the anterior vaginal wall.
There are hints in the literature that erosion may be related to technique – perhaps to the depth of dissection during surgery – but this is difficult to quantify. Moreover, many of the reported cases of erosion occur several years, or longer, after surgery. It is hard to blame surgical technique for such delayed erosion.
As we’ve seen with previous generations of mesh, there does not appear to be any window of time after which erosion is no longer a risk. We need to recognize that there is a medium- and long-term risk of erosion and appreciate its presenting symptoms: Recurrent urinary tract infection, pain with voiding, urgency, urinary incontinence, and microscopic hematuria of new onset.
Prevention may well entail preoperative estrogenization. The science looking at the effect of estrogen on sling placement is becoming more robust. While there are uncertainties, I believe that studies likely will show that topical estrogen in the preoperative and perioperative phases plays an important role in preventing erosion from occurring. Personally, I am using it much more than I was 10 years ago.