The Effect of Endoscopic Injections of Dextranomer Based Implants on Continence and Bladder Capacity: A Prospective Study of 31 Patients

Abstract

A prospective study was conducted to assess the efficacy of dextranomer based implants as a new bulking agent for endoscopic treatment of pediatric structural incontinence.A total of 33 children and adolescents 5 to 18 years old with severe incontinence due to sphincteric incompetence (exstrophy-epispadias in 13, neuropathic bladder in 16, bilateral ectopic ureters in 4) were enrolled in the study. All but 1 patient wore diapers. Preoperative evaluation consisted of medical history, pad test, urine culture, urinary tract ultrasound and videourodynamics. This evaluation was repeated 6 months and 1 year after treatment and then on a yearly basis. Of the patients 14 had 2 and 1 had 3 treatment sessions to achieve a definitive result. At each evaluation the patient was considered cured-dryness interval of 4 hours confirmed by pad test, significantly improved-minimal incontinence requiring no more than 1 pad a day with less than 10 gm. leakage during pad test; and no further treatment required, and treatment failure-no significant improvement. Videourodynamics were mainly useful to study the evolution of the bladder capacity, activity and compliance. Followup after the last injection ranged from 6 to 36 months (mean 18).The mean injected volume was 3.9 ml. (range 1.6 to 12) and the procedure lasted a mean of 30 minutes (10 to 60). In the postoperative period 2 patients had temporary dysuria and 10 had a nonfebrile urinary tract infection. At 1 month 24 of the 33 patients (73%) were dry or improved. Two patients were subsequently excluded from study for noncompliance with followup. At 6 months 17 of 31 patients (55%), at 1 year 13 of 28 (46%), at 2 years 10 of 23 (43%) and at 3 years 10 of 20 (50%) were dry or improved. Similar success occurred in cases of neuropathic bladder (57%) and exstrophy-epispadias complex (46%). Success rate of re-treated patients was 35%. Of 13 patients with a normal initial bladder capacity 3 had a bladder decompensation requiring augmentation after 6 months. Also an increase of at least 50% in capacity was observed in 12 of 18 patients with an initial small bladder. No side effect related to the substance was observed.Endoscopic treatment of pediatric structural urinary incontinence with dextranomer implant, a nontoxic, nonimmunogenic, nonmigrant synthétic substance, was effective after 3 years in half of our patients. It may also be beneficial for patients with small bladder functional capacity. As the success rate decreased during the first year of followup, the result observed at 1 year seems to remain stable subsequently.