Sándor LOVÁSZ, Péter TENKE
Urological Department, Jahn Ferenc Teaching Hospital, Budapest, Hungary

Aim: Topical intravesical medication via transurethral instillation
shows several advantages over oral or systemic therapy.
Intravesically administered drugs penetrate into vesical mucosa
and submucosa by passive diffusion. In order to enhance drug
transport, diuresis reduction had been widely used to prevent concentration
reduction and to prolong time of action. We sought for
a new method to enhance drug transport by profiting from high
pressure difference, and increased surface with thinning of bladder
mucosa at the same time.

Methods: We invented the use of a special balloon dilationcatheter
inside the bladder that let us press any sort of drug previously
injected around the balloon into the bladder mucosa by growing pressure as balloon grows bigger and bigger. As soon as
pressure reaches 80 cm H20 intravesical pressure (relative to
perivesical pressure), it is kept constant for a max. of 20 minutes.
Intravesical pressure can be measured indirectly inside the balloon
by subtracting perivesical pressure + balloon’s characteristics
from actually measured value.

Results: Our method let positively influence all parameters influencing
passive drug diffusion through urothelium (concentration
gradient, time of action, surface, diameter of urothelium). In
addition exact measurement of pressure-volume relation can be
used for the calculation of distensibility of the bladder wall.
Conclusion: Presented method of high pressure local intravesical
medical treatment of the bladder may provide a number of clinical
trials using different drugs (antibiotics, antiphlogistics,
steroids, hormones, local anaesthetics, etc.) and contribute to
improved efficacy of instillation therapy.