[1] Univ Maryland, Ctr Med, Dept Otorhinolaryngol Head & Neck Surg, Baltimore, MD 21201 USA
[2] Mayo Clin & Mayo Fdn, Coll Med, Dept Otolaryngol Head & Neck Surg, Rochester, MN 55905 USA
[3] Mayo Clin & Mayo Fdn, Coll Med, Dept Lab Med & Pathol, Rochester, MN 55905 USA