Periurethral collagen injection for the treatment of urinary incontinence in children

Purpose: We assessed the efficacy and safety of periurethral collagen injection for urinary incontinence in children with neurogenic bladder dysfunction. Materials and Methods: We treated 11 children (mean age 10.6 years) who had incontinence and neurogenic bladder dysfunction with periurethral injections of glutaraldehyde cross-linked collagen. All patients were on anticholinergics and all but 1 were on clean intermittent catheterization preoperatively. Four patients had previously undergone augmentation cystoplasty. All patients were assessed before and after injection with a subjective continence scale and multichannel urodynamics. Followup ranged from 4 to 20 months from the last injection. Results: Mean group Valsalva leak point pressure was 34.5 cm. water. Four of the 11 patients had an identifiable detrusor leak point pressure. Overall success rate was 55% with 4 patients dry and 2 improved. Success correlated with a minimum increase in Valsalva leak point pressure of 20 to 25 cm. water to greater than 60 cm. water. Three patients had no demonstrable Valsalva leak point pressure after injection. All 5 patients in whom treatment failed had no change in Valsalva leak point pressure, including 2 with small capacity, poorly compliant bladders preoperatively. Because they had a component of sphincteric insufficiency, they underwent injection in the hope of increasing capacity with increased continence. In 3 patients Valsalva leak point pressure was greater than 50 cm. water. Detrusor leak point pressure developed in 3 patients postoperatively, including 1 with significantly increased Valsalva leak point pressure. One patient with significantly increased Valsalva leak point pressure had urethral hypermobility postoperatively. Of the 3 patients who subsequently underwent augmentation cystoplasty 1 is now dry, 1 is wet and 1 died of complications unrelated to urological disease. Patients underwent 1 to 4 procedures (mean 2.5). Conclusions: Periurethral collagen injection may be effective for urinary incontinence in patients who have adequate capacity with good compliance and low Valsalva leak point pressure. When there is no response to repeat injections or a transient response, one should consider the possibility of bladder decompensation.