Effect of Mirabegron on Bladder Compliance

In many cases of neurogenic bladder patients, bladder compliance is lowered, which is a factor that deteriorates renal function. It is known that deterioration of renal function is accompanied in 50 to 70% of patients with low bladder compliance. For patients with poor bladder compliance, a consensus has not yet been established regarding the treatment method. This is especially true in the case of drug treatment rather than surgical methods. There are limited cases where bladder compliance is improved with anticholinergics, which have been conventionally administered to the patients. According to the existing literature, increase of bladder compliance was observed in some patients with anticholinergics such as tolterodine, propiverine, and oxybutynin. But the bladder compliances were not completely normalized in every patient. Moreover, adverse effects of anticholinergics have been reported in a significant number of the patients. The objective of this study is to analyze the effect of mirabegron (a beta3-adrenoceptor agonist) on bladder compliance in patients who had no effect on bladder compliance with prior anticholinergics treatment. In this study, low bladder compliance is defined as 20 ml/cmH2O or less.