Effect of the intravesical resiniferatoxin instillation evaluated by the ice provocative urodynamic study

Abstract

Study design: Prospective urodynamic investigation before and after intravesical resiniferatoxin instillation treatment. Objective: To evaluate the effectiveness of intravesical resiniferatoxin instillation for the treatment of neurogenic detrusor overactivity (NDO), using conventional and ice provocative urodynamic studies to monitor the activity of the unmyelinated C-fiber. Setting: Spinal Cord Injury Unit, Yonsei Rehabilitation Hospital, Seoul, Korea. Methods: A measure of 100 ml of resiniferatoxin solution, at a concentration of 100 nM diluted in 10% ethanol, was intravesically instilled into the bladder of 15 spinal cord injury patients with NDO. Conventional and ice provocative urodynamic studies were performed to evaluate the change in the involuntary detrusor activity, reflex volume, maximal bladder capacity, compliance, maximal detrusor pressure and reflex volume ratio 7 days before and 30 days after the instillation. Results: Before the intravesical resiniferatoxin instillation, all patients exhibited NDO in both the conventional and ice provocative urodynamic studies, with a mean reflex volume ratio of 0.4570.22. There was no significant change in the maximal bladder capacity, compliance and maximal detrusor pressure at the follow-up urodynamic study, but the reflex volume ratio was significantly increased (Po0.05) after the intravesical resiniferatoxin instillation. Among the 15 patients, three (20%) showed complete and nine (60%) partial suppression of the unmyelinated C-fiber activities. Conclusion: Intravesical resiniferatoxin instillation was partially controlled by the unmyelinated C-fiber activities, which were estimated by an ice provocative urodynamic study. Therefore, further studies on the optimal dosage and accurate indications for resiniferatoxin instillation are required.

Resiniferatoxin and Tetrodotoxin Induced NPY and TH Immunoreactivity Changes Within the Paracervical Ganglion Neurons Supplying the Urinary Bladder

“…Unfortunately, in such concentration the ethanol vehicle alone was noted to be irritating to the bladder mucosa. On the other hand, ethanol potentiated the response of vanilloid receptor-1 to capsaicin and their analogs (de Sèze et al 1998; Trevisani et al 2002; Kuo 2003; Shin et al 2006). After using 10 % ethanol, a small number of inflammatory cells in the lamina propria were reported (Silva et al 2001).…”

“…The aqueous insolubility of RTX necessitates the use of ethanol as a solvent for the instillation of this drug. In clinical trials 30 or 10 % ethanol which was prepared as the same on humans was used as a vehicle solution (Silva et al 2000; Kuo 2003; Shin et al 2006). Thus, the ethanol mixture that contained RTX was used in this experiment.…”

Refractory neurogenic detrusor overactivity

“…As C‐fibres control an involuntary sacral micturition reflex, inactive in normal adults but enhanced in patients with spinal NDO, RTX‐induced desensitisation inactivates the sacral reflex. RTX also suppresses ice‐water‐induced detrusor contractions in NDO patients (25,26). These contractions, which are usually absent in normal persons, are also driven by C‐fibre input.…”

The determination of sensation-dependent bladder emptying time in patients with complete spinal cord injury above T11

“…All others were classified in group B. 1, 16 We performed comparisons of general characteristics and urodynamic and clinical parameters between the two groups.…”

“…13,14 The low-compliance bladder receives special attention clinically because it causes deterioration of renal function as well as the development of hydronephrosis. 15,16 It is possible that there are many lowcompliance neurogenic bladders in complete SCI patients with the preserved desire to void, because the preserved desire to void in complete SCIs will be a vague response to strong stimuli. Therefore, research should first consider how many patients with the preserved desire to void in complete SCIs have well-controlled neurogenic bladders.…”