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.