RESUMO
BACKGROUND: There is a need for an improved version of the implantable catheter for malignant ascites in the abdominal cavity. OBJECTIVE: New implantable catheters have been developed that drain ascites from the abdominal cavity to the bladder by applying pressure. Based on pigtail catheters, these newly designed catheters have silicone membranes and apertures. METHODS: Experimental instruments controlled flow rates and water level to observe changes of the activation pressure and its cycle time along flow rates and turns of catheters. Furthermore, various normality tests, difference tests and non-parametric tests were investigated to observe statistical validity. RESULTS: Cycle times were significantly affected by flow rate (3/4 cases of p< 0.05). The effects of flow rate on activation pressure, however, were not significant (1/4 case of p< 0.05). Cycle times were not significantly affected by the number of turns of the catheter (3/8 cases of p< 0.05). In contrast, the effects of the turns on activation pressure were significant (5/8 cases of p< 0.05). CONCLUSION: Overall, there was no significant difference between cycle times for 1.5 turns and 2.0 turns of catheters. In addition, catheters with 1.5 turns have a lower activation pressure than catheters with 2.0 turns. It is possible to customize catheters based on the ascites excretion and urination rates of various terminal patients.
