AIM OF STUDY
According to Blaivas classification intrinsic sphincter deficiency (ISD) is defined when genuine stress incontinence is associated with a fixed urethra and a maximum closure pressure less than 20cmH2O on urethral pressure profilometry. Women suffering of such condition are reported to have a lower success rate when a Burch colposuspension is performed. Amongst the available treatments for ISD, the intra- or para-urethral injection of different materials (gax collagen, autologous fat, macroplastique etc) has been reported. Macroplastique has the advantage to be readily available, it does not need to be stored in a fridge, it doesn't require a skin test and, theoretically, it should not be reabsorbed like the other materials. The aim of this study is to evaluate the success and the complications rate of macroplastique as a treatment of women with ISD.

METHODS
In this study we only included women with genuine stress incontinence on cystometry with a maximum urethral closure pressure < 20cmH2O and a fixed urethra demonstrated with a < Q-Tip < 30°. All this women underwent an intraurethral injection of Macroplastique, which was repeated after some time up to 3 times when required. The intraurethral injection was performed cystoscopically using a 30° lenses under local anaesthetic. Each time the injection was performed in 3 different points at the level of the bladder neck (Hrs 3-6-9). No catheter was placed after injection and each patient was invited to void spontaneously after maximum of 4 hours. A post-void residual was checked with ultrasound and a catheterisation was performed when needed. All women were reassessed both subjectively and urodynamically at 3, 6, 9 and 12 months. In case of failure women were re-booked for a repeat injection up to 3 times. All the data were then stored into a specifically designed database and analysed.

RESULTS
From 1996 to 1999 we included 20 women with a mean age of 69 years (range 52-87 yrs). Preoperatively five women used no more than 2 pads/day, 9 used 3-4 pads/day and 6 women more than 5 pads/day. The mean maximum urethral closure pressure was 16.5cmH2O (SD ± 7.4 cmH2O) and the mean functional urethral length was 19.5mm (SD ± 3.5mm). Five women had a previous retropubic surgery, 5 vaginal surgery, 1 had a vulvectomy, 3 pelvic radiotherapy whereas 7 had not any previous therapy. A total of 32 macroplastique implants were performed with a mean amount/implant of 5.3ml (range 2.5-10ml) and a mean amount/patient of 8.25ml (range 2.5-17.5ml). After a mean follow-up of 7 months (range 3-13 months) all women were reassessed. Seven women (35%) were subjectively cured and 6 (30%) objectively, eight women (40%) were improved and 5 (25%) the same. Two women (10%) complained of de-novo detrusor instability and no one had voiding difficulties.

CONCLUSION
In this study we found that only 35% of women with intrinsic sphincter deficiency can be cured. However when also improvement is considered the rate of success increases up to 75%. This is reasonably good result, especially considering this group of selected women, which are generally considered at high risk for surgical failure. A longer assessment for efficacy is needed to confirm these data.