An investigation of the basic physics of irrigation in urology and the role of automated pump irrigation in cystoscopy.
OBJECTIVE
To investigate the effects of height, external pressure, and bladder fullness on the flow rate in continuous, non-continuous cystoscopy and the automated irrigation fluid pumping system (AIFPS).


METHODS
Each experiment had two 2-litre 0.9% saline bags connected to a continuous, non-continuous cystoscope or AIFPS via irrigation tubing. Other equipment included height-adjustable drip poles, uroflowmetry devices, and model bladders.


METHODS
In Experiment 1, saline bags were elevated to measure the increment in flow rate. In Experiment 2, saline bags were placed under external pressures to evaluate the effect on flow rate. In Experiment 3, flow rate changes in response to variable bladder fullness were measured.


RESULTS
Elevating saline bags caused an increase in flow rates, however the increment slowed down beyond a height of 80 cm. Increase in external pressure on saline bags elevated flow rates, but inconsistently. A fuller bladder led to a decrease in flow rates. In all experiments, the AIFPS posted consistent flow rates.


CONCLUSIONS
Traditional irrigation systems were susceptible to changes in height of irrigation solution, external pressure application, and bladder fullness thus creating inconsistent flow rates. The AIFPS produced consistent flow rates and was not affected by any of the factors investigated in the study.
Urology Unit, Department of Surgery, University of Melbourne, Austin Health, Melbourne, VIC, Australia.
Dwayne
D
Chang
Rustom P
RP
Manecksha
Konstantinos
K
Syrrakos
Nathan
N
Lawrentschuk
D001331:Automation; D003558:Cystoscopy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008954:Models, Biological; D007507:Therapeutic Irrigation / Q000295:instrumentation / Q000379:methods*; D001743:Urinary Bladder; D014572:Urology