Which sling for which patient?
This roundtable is the first of a series on persistent questions in urogynecology. Future topics: lower urinary tract injury, hysterectomy routes, vaginal vault prolapse.
IN THIS ARTICLE
- How preop evaluation guides the decision
- Intrinsic sphincter deficiency: What it is and what to make of it
- Why the Burch procedure isn’t obsolete
OUR EXPERT PANELISTS
- Mickey Karram, MD, the moderator of this discussion, is director of urogynecology at Good Samaritan Hospital in Cincinnati and professor of obstetrics and gynecology at the University of Cincinnati.
- Jerry Blaivas, MD, is clinical professor of urology, Weill Cornell Medical Center, New York City.
- Mark Walters, MD, is head of the section of urogynecology and reconstructive pelvic surgery, Cleveland Clinic Foundation, Cleveland.
Slings abound, entering the market faster than research can evaluate every new modification as exhaustively as we would like. How should we determine what is best for a particular patient? That is the question we examine in this discussion—the first in a series of roundtables, Controversies in Pelvic Surgery.
Future topics in the series focus on other unsettled issues:
- Preventing and managing lower urinary tract injury
- How best to correct vaginal vault prolapse
- Choosing the right hysterectomy route
- Mesh augmentation in prolapse repair
We decided on a roundtable format for the series because it seems well suited to a review of sometimes spotty data, not to mention the onslaught of new products and procedures that, ironically enough, are intended to simplify our lives.
Choosing a sling for “uncomplicated” cases
DR. KARRAM: What is your sling procedure of choice for the uncomplicated patient who has primary stress urinary incontinence (SUI), urethral hypermobility, and what appears to be a healthy urethra?
DR. BLAIVAS: I prefer an old-fashioned, autologous, rectus fascial sling, or one made of soft prolene mesh, as described by Rodriguez and Raz1—although I place the sling a bit more proximal than most and dissect into the retropubic space. The autologous rectus fascial sling has a long-term success rate at least as good as any other procedure. Even though it requires at least a small suprapubic incision, the possibility of serious complication (vascular or bowel injury, urethral or vaginal erosion) is almost nil.
Allograft and xenograft slings do not have as good a long-term success rate, but the chance of serious complication is nearly nil. If I do use a synthetic, I prefer the technique developed by Dr. Raz because it utilizes a time-honored, safe technique and avoids the unnecessary expense of the disposable midurethral sling kits.
I place the autologous sling at the bladder neck because long-term studies confirm its safety and efficacy.
DR. WALTERS: I use the literature as a guide and perform either Burch colposuspension or a synthetic midurethral sling procedure.Although its popularity has waned slightly, the Burch operation—either open or laparoscopic—is very effective.
My midurethral sling of choice for the simplest cases, as well as those with coexistent prolapse, is the Monarc transobturator sling (American Medical Systems, Minnetonka, Minn). The outcome data for this procedure are preliminary, and it has not yet been shown to equal a classic tension-free vaginal tape (TVT) technique, but I find that it causes less voiding dysfunction and urgency in my hands.
KARRAM: I would probably use a conventional TVT sling procedure. The reason: There is a tremendous amount of data to support the use of TVT for all types of SUI. The data and our experience supports a very low erosion or excursion rate with the TVT tape. Since it is really the only synthetic midurethral sling that has been shown to be as effective as—if not more effective than—conventional repairs, it remains my procedure of choice in uncomplicated cases.
KARRAM: Do you use the same sling procedure for all patients? If so, do you test preoperatively to help determine appropriate tension? If not, how do you decide which sling to use on which patient?
WALTERS: I use 3 types of slings:
- the Monarc transobturator sling for simple primary SUI, SUI with prolapse, and potential SUI,
- TVT placed very loosely for recurrent SUI with leak point pressures over 60 cm H2O, and
- TVT placed with a little more tension under the urethra for patients who have recurrent SUI with leak point pressures under 60 cm H2O, but who lack a complete “drainpipe” urethra.
Technically, I also use a fourth sling—a full fascial sling for severe intrinsic sphincter deficiency (ISD)—although I haven’t done one of these procedures in over a year.
BLAIVAS: For the uncomplicated case, I use either an autologous rectus fascial sling, an allograft or xenograft, or one made of soft prolene mesh, depending on the patient’s preference. zenograft
If I suspect she is at risk for erosion of a synthetic sling due to prior sling erosion, previous pelvic radiation, concomitant urethral diverticulectomy, or pelvic/urethral reconstructive surgery, I avoid synthetics.
“I must emphasize that these are all touchy-feely things”
BLAIVAS: Preoperatively, in addition to a focused history, questionnaire and examination, I make use of diaries, pad tests, video-urodynamics, pressure flow studies, cystoscopy, leak point pressure tests, and the Q-tip test whenever possible.
If the patient has significant urethral hypermobility and a relatively high leak point pressure, I use a bladder neck sling without any added tension. If there is little urethral mobility and a low leak point pressure, I make the sling a bit tighter.
If the woman has impaired detrusor contractility or urethral obstruction according to detrusor pressure uroflow data, I make the sling a bit looser.
I must emphasize that these are all “touchy, feely” things, unsupported by any meaningful data.
I also adjust the tension, depending on the patient’s feelings about intermittent catheterization versus persistent sphincteric incontinence.
That said, there is still a lot more art than science to this issue. I almost always tie the slings very loosely, compared with what I see others saying or doing. I do this because, in my own learning curve, I quickly encountered problems of urethral obstruction but almost never made a sling too loose. As I gained experience, I tied them looser and looser without ever losing clinical efficacy.
KARRAM: I don’t use the same sling for every patient. Like both of you, I first look at the leak point pressure and review the patient’s subjective complaints. I also consider any chronic systemic disorders, such as asthma or chronic obstructive lung disease, that may put a patient at high risk for failure. The findings help me adjust the tension intraoperatively.
I also try to reproduce the stress incontinence with a cough or Valsalva maneuver if the surgery is performed under local anesthesia, or using suprapubic pressure if it is done under general anesthesia.
Most of my sling procedures involve TVT. Although I recently began to selectively utilize a transobturator approach for women with occult incontinence or mild disease, I am not fully convinced it will be as efficacious as a traditional TVT for SUI.
“No matter how slight the modification, each new sling is encumbered by a learning curve”
KARRAM: Industry aggressively promotes new sling procedures—new materials, new placement techniques, new needles to pass the sling material. There are so many products and procedures that it is difficult to compare them all. Do you think this will become a serious problem, with many procedures lumped together and each assumed as effective as a similar product?
BLAIVAS: Emphatically, yes. Each new sling, no matter how slight the modification seems to be, is encumbered by a new learning curve. That means that the first batch of patients each surgeon operates on will be subjected to a higher complication rate or lower efficacy.
There have been unexpected (and unpublished) deaths due to vascular and bowel injuries and a 1% to 9% vaginal or urethral erosion rate with synthetic slings. Disappointing medium-term efficacy of allograft and zenograft slings were recently published, and recent abstracts suggest that transobturator slings are less efficacious for women with ISD.
WALTERS: This problem not only exists, it has been worsening over the past several years. We still don’t know if the transobturator sling is as effective as TVT, for example, yet we are slowly adopting it because it is easier and probably safer.
The various instruments required for these operations may not be that different, but the absorbable and nonabsorbable prosthetic sling materials are. They should be evaluated constantly and compared with the TVT procedure.
In medicine, we can’t control what industry does, but we can continue to study and test the new procedures before we consider them standards.
KARRAM: I agree that the problem already exists. Although we have a substantial amount of data on the TVT mechanism and the Gynecare material (Ethicon, Somerville, NJ), we need to derive data for other slings. This may be very difficult, given the number of different materials and kits already on the market.
“We still don’t know if the transobturator is as effective as TVT, but we are slowly adopting it because it is easier and probably safer”
KARRAM: The current rage is the transobturator approach, although we have very little data about it. Theoretically, it is safer than TVT, since there is no need to pass the needles through the retropubic space, and thus it is unlikely to lead to vascular and bowel, or bladder and urethral injury.
Should go ahead and adopt it as a primary procedure, or do you recommend waiting for more data on its efficacy?
BLAIVAS: I do not recommend that it be adopted until it is proven safe and effective, but I feel the same way about most of the other slings as well. When performed by experts, almost all these procedures are very safe, but we don’t know very much about long-term efficacy. If someone selects the transobturator approach out of fear of complications from a different procedure, he or she is probably not skilled enough to perform these operations in the first place.
KARRAM: I agree that we need to wait until efficacy data are established. As slings become less and less invasive, industry is aggressively pushing them into the hands of novices. Most of the time these are gynecologists who have not performed antiincontinence surgery and may even lack cystoscopy privileges. Do you think this will be a problem down the road?
BLAIVAS: Yes, unless the procedures are dumbed down enough and they are truly safe and effective.
Transobturator and TVT learning curves and outcomes
WALTERS: As for the transobturator approach, I am convinced, based on my surgical experience over the past 2 years, that it is easier than TVT and results in less voiding difficulty and urgency.
However, I am not convinced that it is equivalent to retropubic TVT in cure rates for SUI. This issue especially needs to be rigorously tested.
In my experience, TVT has a very high cure rate for SUI, but can cause urgency, including intractable urge and voiding dysfunction requiring transection of the polypropylene tape. This rarely occurs with the transobturator sling, making it attractive for simple SUI.
The transobturator sling also is easier than TVT to learn and teach, and completely avoids any risk of retropubic hematoma and bowel perforation. Also, unless there is extensive prolapse, the risk of entering the bladder and urethra is practically nil, assuming you are able to pass the needle and touch your finger from the lateral side.
The next big, important study will likely be a randomized comparison of transobturator and TVT slings, similar to the way TVT was compared with the open Burch procedure.
“I perform cystoscopy on virtually every patient, and find abnormalities in 2% to 4% of cases a year”
WALTERS: For their own protection, I don’t think gynecologists should be doing surgery for prolapse and incontinence if they do not have privileges for cystoscopy.
KARRAM: I agree. It is very important that the gynecologists performing these procedures evaluate the patient thoroughly enough to decide wisely between surgical and nonsurgical management. Certainly they should have the ability to evaluate the lower urinary tract with cystoscopy before doing these procedures.