The bacteriostatic properties of ear tubes made of absorbable polylactic acid.

OBJECTIVE: Tympanostomy tube placement remains the most common reason children are brought to the operating room. Of the known complications, transient, recurrent, and chronic otorrhea represent the most common and challenging sequelae of tube insertion. This study was performed to determine if the acidic nature of the polymer of lactic acid (PLA), a possible material for the construction of ear tubes, would have bacteriostatic properties. MATERIAL AND METHODS: Experimental PLA tubes and control fluoroplastic tubes were inoculated with a broth of Pseudomonas aeruginosa or Staphylococcus aureus and incubated. Fluid recovered from the tubes was plated and incubated again. Colony counts were recorded at 24 and 48 h. Two separate trials were conducted for each organism. Repeated measures analysis of variance (ANOVA) models were used to assess the effects of the type of tube, the experimental run, and the tube by run interaction on colony counts. RESULTS: In the Pseudomonas experiments, the mean colony count of the PLA tube group (Run 1: 1.0; Run 2: 26.6) was significantly lower than the mean colony count in the fluoroplastic tube group (Run 1: 132.6; Run 2: 122.2; p=0.0150). Similarly, in the S. aureus experiments, the mean colony count of the PLA tube group (Run 1: 88.2; Run 2: 92.6) was significantly lower than the mean colony count in the fluoroplastic tube group (Run 1: 335.0; Run 2: 325.8; p<0.0001). CONCLUSION: PLA has many properties including an apparent bacteriostatic quality, which may make it an attractive material for the construction of tympanostomy tubes.

A computed tomographic guide to endoscopic sinus surgery: axial and coronal views.

SUMMARY: The purpose of this article is to correlate endoscopic surgical procedures in the sinuses with computer tomographic (CT) scans. Twelve commonly performed procedures were color-coded on a set of normal coronal and axial CT scans. The illustrated procedures are uncinectomy/antrostomy, anterior ethmoidectomy, posterior ethmoidectomy, sphenoidotomy, partial inferior turbinectomy, partial middle turbinectomy, septoplasty, frontal recess approach, dacrocystorhinostomy, orbital decompression, optic nerve decompression, and medial maxillectomy. Drainage of a medial orbital abscess is discussed but not illustrated. A brief description of the indications, surgical approach, and complications of each procedure is also provided.