URINARY INCONTINENCE INJECTION TREATMENT

urinary incontinence injection treatment: The injection of bulking materials into the bladder neck and periurethral muscles is used to increase outlet resistance. Bulking substances include silicone polymers (Macroplastique); cross-linked bovine collagen; Teflon; PTFE; and carbon coated zirconium beads (Durasphere).

Indications of urinary incontinence injection treatment
Stress incontinence secondary to demonstrable intrinsic sphincter deficiency (ISD), with normal bladder muscle function. Used in adults and children.

Contraindications of urinary incontinence injection treatment
UTI; untreated bladder dysfunction; bladder neck stenosis. Improved outcome in patients without urethral hypermobility (which is better treated with a sling or, less commonly, an artificial urinary sphincter).

Pre-injection evaluation
Stress test; Q-tip test; videourodynamics to diagnose ISD and exclude detrusor overactivity.

Injection techniques
Requires either a local block, or a general anaesthetic, with full antibiotic cover. Suburethral injections are given by a transurethral (retrograde) route using a cystoscope and cystoscopic injection needle to inject the bulking agent suburethrally. In men, the injection should be proximal to external sphincter to avoid sphincter spasm, or in the proximal membranous urethra beside verumontanum following radical prostatectomy. In women, a periurethral (percutaneous) technique can also be used, with endoscopic or USS guidance. In women, 2 injections are recommended; in men, 3 or 4 circumferential injections are administered, with the aim of achieving urethral muscosal apposition and closure of the lumen. Overall success rate ~50 - 70%.5,6

Complications of urinary incontinence injection treatment
Urinary urgency; urinary retention (which may need ISC or SPC insertion); haematuria; cystitis; distant migration of the injected particles (PTFE, Macroplastique), and risk of granuloma formation (PTFE), although no adverse consequences are reported. Often, repeat treatments are needed (reinjection rates with collagen are ~20%).