Learning Objectives: Round Table (PET vs FETTO)
Introduction: The importance of PET in otology has long been underestimated. We have achieved some contributions on PET as follows.
Methods and Results:
-
1. We have developed a new technique to diagnose PET using the sitting CT (Kikuchi T, et al. Otol Neurotol, 2007; 28:199–203; Kikuchi T, et al. ORL J Otorhinolaryngol Relat Spec. 2009; 71:312-6.).
-
2. Development of a specially designed silicon plug (Kobayashi Plug) for intractable cases (Sato T, et al. Acta Otolaryngol 2005; 125:1158-63). It is introduced from the myringotomy site, and was effective for about 80% of the 250 ears in which other treatments were unsuccessful (Kikuchi T, et al. in preparation)
-
3. High incidence in middle ear cholesteatomas: Patulous condition of the Eustachian tube is identifiable in about 30% of middle ear cholesteatomas (Magnuson:1978, Kobayashi:1996, Ohta:2009) and the incidence is higher than 50% if tested after optional myringostomy. The interview on sniffing habit is very important but not enough to pick up all the cases with patulous condition of the ET. In addition to thorough questionnaires, sniff test with optional myringostomy is useful for preoperative diagnosis of PET or Eustachian tube closing failure (Asawapittayanont P, et al. submitted).
-
4. ‘Masked Patulous Eustachian Tube’: We have proposed the concept of ‘masked patulous Eustachian tube’ (Masked PET) (Kobayashi T et al: Tohoku J Exp Med. 2009; 218:317-24) frequently found in middle ear diseases causing conductive hearing loss, such as cholesteatomas, otosclerosis, and perforations of the tympanic membrane, etc. In this condition, symptoms of PET are concealed due to the hearing loss and appears after improvement of hearing by surgery (Hasegawa J, et al.: Acta Otolaryngol. 2006; 126:577-80; Kawase T, et al: Otol Neurotol. 2006; 27:600-3; Hori Y, et al:Otol Neurotol. 2006; 27:596-9).
Discussion: I will discuss the topics of this session, differentiation between PET and FETTO, based on the above mentioned personal experience.