Objective
The purpose of this study was to evaluate the clinical effectiveness of intravesical oxybutynin chloride instillation in the management of neurogenic bladder dysfunction in spinal cord injured patients.

Method
Fifty-two spinal cord injured patients with hyperreflexic or hypertonic neurogenic bladder were treated with intravesical oxybutynin instillation therapy. The purified oxybutynin chloride was dissolved in sterile water and mixed with normal saline. This oxybutynin solution was instilled twice a day for 7 days. The urodynamic studies were compared before and after the instillation. Total volume of daily incontinence was also monitored.

Results
After the intravesical oxybutynin instillations, mean maximal bladder capacity increased from 212.13 to 323.81 ml (p＜0.01), mean bladder compliance increased from 11.73 to 18.56 ml/cmH₂O (p＜0.01), mean maximal detrusor pressure decreased from 67.19 to 50.90 cmH₂O (p＜0.01) and mean daily amount of incontinence decreased from 735.58 to 201.73 ml (p＜0.01). No significant differences were found between the groups according to the level of injury, completeness of injury, duration since onset of injury and the presence of asymptomatic bacteriuria.

Conclusion
This study proved that intravesical instillation of oxybutynin solution is an effective method in spinal cord injured patients with hyperreflexic or hypertonic neurogenic bladder dysfunction regardless the level and completeness of injury, as well as duration since the onset of injury or the presence of asymptomatic bacteriuria.