Report: Most studies on mini-slings of low quality

February 1, 2011

Many studies on mini-slings have widely varying outcome measures as well as insufficient follow-up periods.

Key Points

Toronto-Many studies on mini-slings have widely varying outcome measures as well as insufficient follow-up periods, researchers from South Africa and the United Kingdom recently reported.

The systematic review was designed "to be inclusive and get enough numbers," said first author Stephen Jeffery, MD, a consultant urogynecologist at Groote Schuur Hospital and the University of Cape Town in Cape Town, South Africa. "We did include a lot of the studies, but the quality of the studies overall was not good."

One of the shortcomings of the studies is a lack of standardization in outcome measures, noted Dr. Jeffery, who presented the findings at the 2010 joint meeting of the International Continence Society and the International Urogynecological Society.

Dr. Jeffery and colleagues identified 59 studies that they regarded as suitable for inclusion in the review, but two were excluded because subjects were not human or were cadavers. The remaining 57 studies consisted of 11 published articles in peer-reviewed journals and 46 conference abstracts. Other outcome measures included urodynamic testing and pad testing.

The majority of the studies (37) used the Gynecare TVT SECUR (Ethicon Inc., Somerville, NJ), while another 12 used the MiniArc (American Medical Systems, Minnetonka, MN), and one used the Ajust (Bard Medical, Murray Hill, NJ). Five studies did not identify the slings that were used, and others used several slings.

A total of 32 studies indicated the type of study that was conducted: a randomized, controlled trial, retrospective analysis, or prospective analysis. A total of 45 studies took into account the follow-up period, with the mean follow-up period for all studies being 36 weeks. Thirty of 45 studies had a follow-up of more than 6 months, and Dr. Jeffery emphasized that less than 6 months follow-up is not adequate to make conclusions about efficacy.

Third of studies have insufficient follow-up

"A third of studies reported less than 6 months' follow-up. As a paper, this may raise more questions than provide answers" about the efficacy of mini-slings, Dr. Jeffery said.

The researchers found the overall subjective cure rate to be 70%, while the overall objective cure rate was 81%. The objective cure rates often surpassed the subjective cure rates.

"Just because the patient is not leaking does not the mean the patient is cured," Dr. Jeffery pointed out. "Someone could not be leaking, but have groin pain or have a problem voiding."

The risk of bladder injury and groin and hip pain after insertion of the mini-slings was less than 1%, which is less than complication rates reported after insertion of retropubic and trans-
obturator tapes.

The rate of groin pain should not be given considerable weight since only 11 trials included in the review reported on that complication, noted Dr. Jeffery, adding that mini-slings have been purported to avoid the risk of groin pain.

"If you are trying to motivate people to use mini-slings, then you should report on that complication," he said.

Dr. Jeffery has received travel grants and speaker fees from American Medical Systems and Johnson & Johnson and has received honoraria from Bard Medical.