Knudson Matthew J, Cooper Christopher S, Block Craig A, Hawtrey Charles E, Austin J Christopher
Division of Pediatric Urology, Department of Urology, University of Iowa, 200 Hawkins Drive, Iowa City, IA 52242, USA.
J Urol. 2006 Sep;176(3):1143-6; discussion 1146. doi: 10.1016/j.juro.2006.04.059.
We report the incidence of calcifications developing at the bladder neck/urethra in pediatric patients treated with glutaraldehyde cross-linked collagen for urinary incontinence.
We reviewed charts of patients treated with glutaraldehyde cross-linked collagen injections for urinary incontinence between 1994 and 1999. Etiology of incontinence, pertinent medical history, operative details and postoperative imaging were examined.
Of 31 patients 4 (13%) had development of submucosal calcifications in the bladder neck/urethra. All 4 patients had received multiple injections of glutaraldehyde cross-linked collagen for incontinence secondary to neurogenic bladder. The calcifications were confirmed surgically. Pathology reports available for 2 of 4 patients showed chronic inflammation without dysplasia or malignant changes. Mean followup was significantly different between calcified and noncalcified cases (10.3 vs 7.2 years, p = 0.009), as was total volume of collagen injected (21 vs 12 cc, p = 0.012). Mean time to diagnosis of calcifications was 8.8 years (range 7 to 11) after first injection. A total of 24 patients without calcification underwent bladder imaging at a mean of 6.8 years (+/-2.2) after glutaraldehyde cross-linked collagen injection, which was not significantly different than the time to diagnosis (p = 0.089). The number of injections was not significantly different between the 2 groups (p = 0.426).
Of our patients 13% had development of calcifications at the site of prior glutaraldehyde cross-linked collagen injections for incontinence. These calcifications were surrounded by chronic inflammation. Patients who have undergone glutaraldehyde cross-linked collagen injections may benefit from long-term followup with bladder imaging to detect and follow calcifications at prior injection sites.
