Mechanical evaluation of balloon-type gastrostomy devices

Purpose is to evaluate the durability of two commonly used gastrostomy devices. The performance of balloon-type gastrostomy devices was evaluated in an accelerated aging failure mode as well as a feeding tube interlock pullout failure mode. Two commonly used devices were tested: MINI (Applied Medical Technology Inc.) and MIC-Key (Kimberly Clark/Ballard Medical). In the aging test, devices (n = 20) from each manufacturer were pressurized and subjected to controlled pH and temperature conditions to evaluate the product life. In the pullout failure test, devices were subjected to controlled mechanical loading to evaluate the force at which each plastic interlock pulls out of the rubber that encapsulates it. In the aging testing, the MIC-Key devices had a lifespan of 98 ± 34 h and the MINI survived for 1187 ± 422 h. The difference was statistically significant (p < 1 × 10-9). In the pullout testing, the MIC-Key failed at 183 ± 24 N whereas the MINI failed at 202 ± 26 N (p < 0.04). Pullout strength for both devices appears adequate in view of estimated in vivo loads during normal use of the device with the MINI requiring a statistically significantly greater pullout strength. Although the aging tests were performed using an accelerated protocol, the aging tests suggest that the in vivo lifespan and failure mode of the MINI may be superior to the MIC-Key.