The InVance sling was designed to treat incontinence following radical prostatectomy in adult males. We have adapted this procedure to treat incontinence in boys that arises from an incompetent bladder neck. We have used this technique for the past seven years in boys with a history of spina bifida, spinal cord injury as well as bladder exstrophy and describe our results.
Since April of 2005, seventeen boys have been treated for incontinence resulting from an incompetent bladder neck. There ages at the time of surgical treatment ranged from seven to twenty years. Followup ranged from 24 months to 74 months. All patients underwent pre-operative urodynamics demonstrating adequate bladder capacity and compliance. Cystography confirmed the presence of an incompetent bladder neck. The patients underwent the placement of an out-patient perineal bulbar urethral sling (AMS InVance) and then resumed intermittent catheterization either via the urethra or through a mitrofanoff.
Of the seventeen boys undergoing this procedure, 65 % (11/17) are improved. Of this number 27 % (3/11) are dry and the remaining 73 % (8/11) are damp with occasional pad use. The remaining 35% (6/17) are failures with 6/17 being completely wet of which 3 required sling removal for infection. Of the improved patients, only one went on to bladder decompensation requiring subsequent augmentation. Of the 11 improved patients 45% (5) required some form of revision, primarily for screw displacement. No patients experienced urethral erosion and no patients had difficulty with catheterization post sling placement.
The AMS InVance sling has been employed in our patient population with mixed success. While 65% are improved, only 18% are completely dry. Of those with improvement, a significant number required revision as the result of inadequate anchor fixation. The relatively small screw size (5mm) used in the AMS InVance system may not have sufficient bone stability for the long term compressive demands in these pediatric patients. Other challenges faced by this approach include an 18% infection rate. While the compressive bulbar sling can be effective, modification to the current approach must be made before it can be generally recommended.