Publications
Ethan Sherman, Patrick Antonelli, Roger Tran-Son-Tay.
In-vitro testing of tympanostomy tube occlusion.
Otolaryngol Head Neck Surg. 2009 Nov;141(5):598-602
Objective: Tympanostomy tubes (TTs) are commonly rendered non-functional by mucus plug formation. The purpose of this study was to determine if an in vitro model could be developed to assess TT plug formation with results consistent with human trials. Study Design: An ear chamber was designed to mimic middle ear air and mucus flow conditions in post-TT otorrhea. TT occlusion was tested and correlated to published in vivo results. Methods: TTs that had previously been studied in vivo (Goode T, and Reuter Bobbin collar buttons) were placed in the model chamber. Pooled, homogenized, human middle ear mucus and an analog, egg white, were delivered at 80 ul per hour through the TTs. An air bolus was delivered every two minutes to simulate swallowing. Chamber pressure was monitored over 2.5 hours. Occlusion was determined by a pressure peak and visual confirmation. Results: Obstruction was found in 60% of the Reuter Bobbin and 40% of the Goode TTs using the mucus analog. These results are similar to those reported from previous in vivo studies. No plugging was reported for either TT using homogenized human ear mucus. Conclusions: The in vitro TT chamber simulates the in vivo environment and yields results consistent with in vivo observations. This model system may allow for rapid prototyping and evaluation of new TTs that may be less vulnerable to occlusion.
http://www.ncbi.nlm.nih.gov/pubmed/19861197
Ethan Sherman, Patrick Antonelli, Roger Tran-Son-Tay.
Development of a calcium alginate tympanostomy tube.
Laryngoscope. 2010 Dec;120(12):2473-7
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.
Herrero NA, Sherman EG, Adelson RT.
Analysis of flap tension in surgical rejuvenation of the midface: a cadaver study.
Otolaryngol Head Neck Surg. 2011 Feb;144(2):191-5
OBJECTIVE: To determine the flap tension present for 2 different surgical approaches for midface lifts and whether a gingivobuccal incision for release of the midface periosteum will diminish the resultant load on the midface flap. STUDY DESIGN: Cadaver study. SETTING: Anatomy laboratory at the University of Florida. SUBJECTS AND METHODS: Twelve fresh-frozen cadaver heads are subjected to a transblepharoplasty (TB) approach on one side of the cadaver head while a transtemporal (TT) approach is performed on the contralateral side. The tension (grams) generated by moving the midface flap a distance of 1.03 cm is recorded by a digital load cell. A gingivobuccal incision is made on each side to allow transoral periosteal release (TOPR) of the midface flap, and the experiment is repeated. Three trials are performed for each operation, and the average load is calculated. A paired t test is applied. RESULTS: The tension resulting from the TT approach (172 g) was not found to be significantly different from that of the TB approach (179 g; P = .75). Significant differences in the resultant tension were not appreciated when comparing standard techniques to TT with TOPR (141.5 g; P = .27) or for TB with TOPR (164.1 g; P = .45). DISCUSSION: An experimental method is described for determining flap tension in facial rejuvenation surgery. No significant difference is found between flap tensions generated in the TB and TT approaches to the midface.
Patel NA1, Sherman EG, Antonelli PJ.
Effect of tympanostomy tube surface on occlusion.
Int J Pediatr Otorhinolaryngol. 2012 Jul;76(7):960-2
OBJECTIVE: Premature tympanostomy tube (TT) occlusion frequently leads to TT replacement surgery. TT surface preparations have been suggested as a means of reducing TT occlusion. The purpose of this study is to determine if commercial TT compositions or surface preparations impact the rate of TT occlusion using an in vitro model. METHODS: Commercial TTs composed of titanium, fluoroplastic, and silicone, as well as human serum albumin coated titanium, phosphorylcholine coated fluoroplastic, and polyvinylpyrrolidone coated silicone TTs, were tested for occlusion development in a previously validated in vitro model that simulates middle ear air and mucus flow. RESULTS: Time to occlusion was longer with all coated TTs relative to all uncoated TTs (p=0.038). Polyvinylpyrrolidone coated silicone TTs had the lowest rate of occlusion and improvement relative to silicone (36% vs. 70%). Time to occlusion was longer in all coated TTs, but individually, none reached statistical significance. CONCLUSION: TT composition and surface preparations do not dramatically impact the development of TT occlusion. All tested surface coatings seem to delay TT occlusion in this in vitro model. In vivo testing will be necessary to validate these findings.