Is the Keros classification alone enough to identify patients with the 'dangerous ethmoid'? An anatomical study.
CONCLUSIONS
By means of three-dimensional display of the critical measurements, the authors suggest a novel definition of 'dangerous ethmoid'. Parallel to Keros type III, the proposed determining factors include: olfactory fossa width >6 mm, its distance to the medial nasal concha (turbinate) <20 mm and to the orbit interval of <10 mm. Clinical evaluation of these preliminary criteria based only on radiological data is required and underway.


OBJECTIVE
Detailed pre-operative assessment of sinus computer tomography (CT) scans reduces the frequency of severe complications in patients undergoing endoscopic sinus surgery (ESS). The authors aimed to identify a sub-set of anatomical features pre-disposing to major post-operative complications.


METHODS
Sinus computer tomography (CT) scans of patients of a single institution qualified for ESS were examined. Besides the Keros classification, authors focused on the anatomic measurements as follows: the olfactory fossa depth, width, and its distance from the medial nasal concha and the medial wall of the orbit (referred to as 'critical measurements'). The sample comprised 120 consecutive CT exams, without clinical validation.


RESULTS
Keros type I, II, and III was noted in 9.2%, 75.8%, and 15.0% of cases, respectively. Despite some statistically significant correlations, it was not possible to identify the patient age, sex, and side of body clearly correlating with the critical measurements.
a Department of Otolaryngology , Medical University of Gdańsk , Gdansk , Poland.
Andrzej
A
Skorek
a Department of Otolaryngology , Medical University of Gdańsk , Gdansk , Poland.
Dmitry
D
Tretiakow
b Department of Neurosurgery , Medical University of Gdańsk , Gdansk , Poland.
Tomasz
T
Szmuda
a Department of Otolaryngology , Medical University of Gdańsk , Gdansk , Poland.
Tomasz
T
Przewozny
D000328:Adult; D000368:Aged; D005004:Ethmoid Bone / Q000000981:diagnostic imaging* / Q000293:injuries; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D057605:Natural Orifice Endoscopic Surgery / Q000009:adverse effects*; D013517:Otorhinolaryngologic Surgical Procedures / Q000009:adverse effects*; D010256:Paranasal Sinuses / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
CSF leakage; Ethmoid bone; Keros classification; endoscopic sinus surgery