Silastic slings for female incontinence

Biocompatibility assessment of synthetic sling materials for female stress urinary incontinence

PURPOSE

We evaluated the performance and complications of currently available synthetic sling materials with a focus on in vitro and in vivo biocompatibility, and acceptance in the human body.

MATERIALS AND METHODS

We reviewed the MEDLINE database for relevant literature pertaining to various synthetic sling materials. The Food and Drug Administration regulations regarding the regulation and biocompatibility testing of synthetic meshes were also reviewed.

RESULTS

Many synthetic meshes used for sling construction were introduced before rigorous Food and Drug Administration regulations were passed and, thus, some became associated with unique complications. Most meshes used in pubovaginal and mid urethral sling surgery are associated with high short-term success rates and relatively few intraoperative complications. Despite modifications and additives, slings constructed from polytetrafluoroethylene and polyethylene are poorly accepted by the human body. Flexible, macroporous, polypropylene meshes appear to integrate more completely with human tissue than other synthetic materials. However, multifilament and nonknitted polypropylene slings may integrate poorly.

CONCLUSIONS

The composition, weave and pore size of each material are unique. These properties are responsible for the strength and durability of the material, as well as the ultimate acceptance and incorporation in the human body. Each material should be individually evaluated and patients should be counseled appropriately before implantation.

Bladder neck pubovaginal slings

Over the past 30 years, the pubovaginal sling has surpassed retropubic and transvaginal suspensions as the most common surgical operation for correcting stress urinary incontinence. This resurgence has been due in part to innovative technological advances that have shortened operative times and expedited postoperative recovery. The introduction of novel allografts, xenografts and synthetic materials has also been accompanied by unique complications, previously not encountered with autologous materials. The aim of this review is to compare the available sling materials in the context of biocompatibility and efficacy.

Laparoscopic colposuspension in women with previously failed anti-incontinence surgery

OBJECTIVES

To assess the effectiveness of laparoscopic colposuspension after previously failed anti-incontinence surgery.

METHODS

Retrospective review of 10 cases, all with urodynamically proven grade 2 genuine stress incontinence.

RESULTS

All patients were subjectively cured at 3 months or more follow-up. The mean hospital stay was 2.9 days, the mean time until normal voiding was 1.7 days, and the mean blood loss was 39 ml.

CONCLUSION

Laparoscopic colposuspension may be useful after failed anti-incontinence surgery. However, larger numbers are needed with objective longer term follow-up.

A follow up of silastic sling for genuine stress incontinence

OBJECTIVE

To assess the use of silastic sling for genuine stress incontinence.

DESIGN

Retrospective descriptive analysis.

SETTING

Tertiary referral centre for urogynaecology.

SUBJECTS

Eighty-eight women with urodynamically proven genuine stress incontinence, 10 had coexistent detrusor instability. In 74 women, the sling operation was for recurrent incontinence.

INTERVENTION

A low Pfannenstiel incision was used and a suburethral tunnel dissected to insert the sling, which was attached under minimal tension with non-absorbable sutures to each ileopectineal ligament.

MAIN OUTCOME MEASURES

Clinical and urodynamic data were assessed between two and three months post-surgery; thereafter clinical assessment and pad testing were performed at yearly intervals for five years.

RESULTS

The subjective cure at three months was 81% and the objective cure was 69%. There was a fall in success rate with increasing number of continence operations, and this was statistically significant for women with three or more previous continence operations (P < 0.05). Neither age, parity nor menopausal status made a statistical difference to the cure rate. Twenty-three women had reached their fifth year follow up and the success rate using life table analysis was 71%. Post-operatively, 29 women had detrusor instability: 22 women developed detrusor instability de novo and seven had detrusor instability presurgery. Urodynamic findings postsurgery showed an increase (P < 0.001) in outflow resistance. Four women required removal of sling for voiding difficulties. Ten women developed sling erosions: five vaginal, four bladder erosions and one urethral erosion. After removal of the sling, seven women still remained continent.

CONCLUSIONS

A silastic sling operation for the treatment of genuine stress incontinence provides a good long term cure, considering that 45% of women had two or more previous failed continence operations. The high prevalence of detrusor instability and voiding difficulties postsurgery should be noted.

The effect of obesity on the outcome of successful surgery for genuine stress incontinence

In a study of 190 patients with genuine stress incontinence, 91 patients were of normal weight, 66 overweight and 33 obese as determined by their Body Mass Index at the time of operation which was either a colposuspension (143) or a silastic sling insertion (47). Body mass index was found to significantly alter the outcome.