Development of a calcium alginate tympanostomy tube.

Objectives/hypothesis: Tympanostomy tubes (TTs) are prone to complications resulting in part from the unpredictable duration that the TT remains in the tympanic membrane. General anesthesia may be necessary to remove TTs that fail to extrude. The purpose of this study was to develop a TT that could be dissolved on demand but remain functional with exposure to common otologic exposures.

Study Design: Prospective in vitro analysis.

Methods: Dissolvable TTs were developed from calcium alginate. Mechanical properties and occlusion susceptibility were optimized by varying ingredient concentrations and compared to commonly used commercial TTs using in vitro measures.

Results: Alginate TTs had a greater compressive strength than commercial silicone tubes. TTs composed of 0.5 M CaCl were stronger than high molarity CaCl concentrations. Uncoated alginate TTs showed a 20% reduction in occlusion propensity. Exposure of alginate TTs to otological solutions for 24 hours resulted in degradation of their mechanical properties, but they remained superior to commercial silicone TTs.

Conclusions: Alginate TTs appear to be a good alternative to commercial tubes based on high mechanical strength and low occlusion propensity. Furthermore, unlike commercial TTs, alginate TTs have the potential to be dissolved in vivo if retained.