[Reiterated intravesical instillation of capsaicin in neurogenic detrusor hyperreflexia: a 5-years experience of 100 instillations].

INTRODUCTION: Capsaicin is a topic and specific C-fiber afferent neurotoxic. After spinal-cord injury, C-fiber afferent proliferate in the bladder mucosae and are involving in detrusor hyperreflexia

AIM OF THE STUDY: To investigate middle-term efficacy and tolerance of intravesical instillation of capsaïcin in spinal-cord injured patients presenting severe urinary incontinence refractory to usual therapy due to detrusor hyperreflexia.

METHODS: Thirty patients receveid a first intravesical instillation of 1mMol/L Capsaïcin solution in 30% alcohol. The efficacy (voiding diary, pads, quality of life, maximum cystometric capacity, maximum detrusor pressure, first and normal desire to void) and tolerance were evaluated before, 1 month and 3 months after each instillation, completed by anual cystoscopy. In patients who responded favorably to this instillation, repeated instillations were proposed when symptoms recurred.

RESULTS: 25 patients (83.3%) were improved after the initial instillation (decrease of incontinence-frequency-urgency, best quality of life, rise on maximal cystometric capacity), since the 15(th) day and for 3.2 months. 76 reiterative instillations were performed in 22 patients (2 to 9 instillations per patient). 91.2% of them remained successfull, during an average period of 4.2 months. It does not appear loss of benefits after iterative instillations. Transient and moderate adverse effects followed 86% and 79% of the first and reiterated instillation (exacerbation of incontinence, supra-pubic pain). Two patients have presented a begnin and transient inflammatory cystitis after reiterated instillation.

DISCUSSION-CONCLUSION: Intravesical instillation of capsaïcin are an effective treatment for incontinence and associated symptoms caused by neurogenic detrusor hyperactivity. Propositions to improve immediate tolerance are debated.