Dos and don'ts for handling common sling complications.
Oftentimes, complications can be significantly more impactful than the original urinary incontinence. It is important to take the complications of sling placement seriously. Let patients know that their symptoms matter, and that there are ways to manage complications.
With more long-term data and experience, we have learned more about what to do, and what not to do, to prevent, diagnose, and manage the complications associated with midurethral slings. Here is my approach to the complications most commonly encountered, including bladder perforation, voiding dysfunction, erosion, pain, and recurrent stress urinary incontinence.
I will not address vascular injury in this article, but certainly, this is a surgical emergency that needs to be handled as such. As described in the February 2015 edition of Master Class on midurethral sling technique, accurate visualization toward the ipsilateral shoulder during needle passage is an essential part of preventing vascular injuries during retropubic sling placement.
Bladder perforation has consistently been shown to be significantly more common with retropubic slings than with transobturator slings. Reported incidence has ranged from 0.8% to 34% for tension-free vaginal tape (TVT) procedures, with the higher rates seen mainly in teaching institutions. Most commonly, the reported incidence is less than 10%.
Bladder perforation has no effect on the efficacy of the treatment, and no apparent long-term consequences, as long as the injury is identified. Especially with a retropubic sling, cystoscopy should be performed after both needles are placed but prior to advancing the needles all the way through the retropubic space. Simply withdrawing a needle will cause little bladder injury while retracting deployed mesh is significantly more consequential.
I recommend filling the bladder to approximately 300 cc, or to the point where you can see evidence of full distension such as flattened urethral orifices. This confirms that the bladder is under enough distension to preclude any mucosal wrinkles or folds that can hide a trocar injury.
The first step upon recognition of a perforation is to stay calm. In the vast majority of cases, simply withdrawing the needle, replacing it, and verifying correct replacement will prevent any long-term consequences. On the other hand, you must be fully alert to the possibility that the needle wandered away from the pubic bone, and consequently may have entered a space such as the peritoneum. Suspicion for visceral injury should be increased.
Resist the temptation to replace the needle more laterally. This course correction is often an unhelpful instinct, because a more lateral replacement will not move the needle farther from the bladder; it will instead bring it closer to the iliac vessels. Vascular injuries resulting from the surgeon's attempts at needle replacement are unfortunate, as a minor complication becomes a major one. The key is to be as distal as possible--as close to the pubic bone as possible--and not to replace the needles more laterally
Postoperative drainage for 1-2 days may be considered, but there is nothing in the literature to require this, and many surgeons do not employ any sort of extra catheterization after surgery where perforation has been observed.
Some degree of voiding dysfunction is not uncommon in the short term, but when a patient is still unable to void normally or completely after several days, an evaluation is warranted. As with bladder perforation, reported incidence of voiding dysfunction has varied widely, from 2% to 45% with the newer midurethral slings. Generally the need for surgical revision is about 2%.
There are two reasons for urinary retention: insufficient contraction force in the bladder or too much resistance. If retention persists beyond a week--in the 7- to 10-day postop time period--I assess whether the problem is resulting from too much obstruction from the sling, some form of hypotonic bladder, other surgery performed in conjunction with sling placement, medications, or something else.
Difficulty in passing a small urethra catheter in the office may indicate excessive obstruction, for instance, and there may be indications on vaginal examination or through cystoscopy that the sling is too tight. A midurethral "speed bump," or elevation at the midpoint, with either catheterization or the scope is consistent with overcorrection.
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 overresistance, 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 ingrowth 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 postTVT 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.
I like the convenience of the Vagifem tablet (Novo Nordisk, Plainsboro, N.J.), and am reassured by data on systemic absorption with the 10-mcg dose, but any vaginal cream or compounded suppository can be used. I usually advise 4-6 weeks of preoperative preparation, with nightly use for 2 weeks followed by 2-3 nights per week thereafter.
Smoking is also a likely risk factor. Data are not entirely consistent, but I believe we should provide counseling and encourage smoking cessation before the implant of mesh.
Management is dependent on when the erosion occurs or is recognized. When erosion occurs within 6 weeks after surgery, primary repair is an option. When erosion is detected after the 6-week window and is causing symptoms, a conservative trim of bristles poking through the vaginal mucosa is worth a try. I do not advise more than one such conservative trim, however, as repeated attempts and series of small resections can make the sling exceedingly difficult to remove if more complete resection is ultimately needed. After one unsuccessful trim, I usually remove the whole sling belly, or most of the vaginal part of the sling.
For slings made of type 1 macroporous mesh, resection of the retropubic or transobturator portions of the mesh usually is not required. In the more rare situation where those pelvic areas of the mesh are associated with pain, I favor a laparoscopic approach to the retropubic space to facilitate minimally invasive removal.
Postop pain, sling failure
Groin pain, or thigh pain, sometimes occurs after placement of a transobturator sling. As I discussed in the previous Master Class on midurethral sling technique, I have seen a significant decrease in groin pain in my patients--without any reduction in benefit--with the use of a shorter transobturator sling that does not leave mesh in the adductor compartment of the thigh and groin.
For persistent groin pain, I favor the use of trigger point injection. Sometimes one injection will impact the inflammatory cycle such that the patient derives long-term benefit. At other times, the trigger point injection will serve as a diagnostic; if pain returns after a period of benefit, I am inclined to resect that part of the mesh.
Pain inside the pelvis, especially on the pelvic sidewall (obturator or puborectalis complex) usually is related to mechanical tension. In my experience, this type of discomfort is slightly more likely to occur with the transobturator slings, which penetrate through the muscular pelvic sidewall and lead to more fibrosis and scar tissue formation.
In most cases of pain and discomfort, attempting to reproduce the patient's symptoms by putting tension on particular parts of the sling during the office exam helps guide management. If I find that palpating or putting the sling on tension recreates her complaints, and conservative injections have provided temporary or inadequate relief, I usually advocate resecting the vaginal portion of the mesh to relieve that tension.
In cases of recurrent stress urinary incontinence (when the sling has failed), a TVT or repeat TVT is often warranted. The TVT sling has been demonstrated to work after nearly every other previous kind of anti-incontinence procedure, even after a previous retropubic sling. There are few data on mesh removal in such cases. I believe that unless a previously placed but failed sling is causing symptoms, there is no need to resect it. Mesh removal is significantly more traumatic than mesh placement, and in most cases it is not necessary.
Caption: Urethroscopy following another physician's attempt at sling loosening with a urethral dilator and downward traction: The urethra gave way before the sling did.
Caption: Laparoscopy weeks after TVT placement: Intraperitoneal segment of mesh shows needle entry during placement; bowel injury was narrowly avoided in this case.
BY CHARLES RARDIN, M.D.
Dr. Rardin reported that he has no relevant financial disclosures.
Please note: Illustration(s) are not available due to copyright restrictions.
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|Publication:||OB GYN News|
|Date:||Apr 1, 2015|
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