Are we mindful of nasal dorsal integrity during septal surgery? An
imaging study of nasal keystone area
Abstract
Objectives: Review of radiological images of the keystone area to assess
risk of disruption to the nasal dorsum when separating the
osseo-cartilaginous junction in septoplasty. Methods: A Cross sectional
radiological study of adults who underwent CT scan of paranasal sinuses.
Outcome measures included were: The Length of the keystone area (shorter
length implies a higher risk of disruption) and a high-risk shape (high
risk shape implies shorter keystone area) that can predispose to
disruption of nasal dorsal integrity during septoplasty surgery. Certain
nasal dimensions were evaluated to determine if they add risk to the
dorsum. Results: CT scans of 343 patients were reviewed. The mean
keystone area length was initially 10.42 mm that came down to 7.43 mm
after adjustment in patients with high-risk shape. 31.5% of subjects
were at risk of disruption to the dorsum due to short keystone area
length <5 mm. Relatively shorter nasal bones (nasal bone
length: overall dorsal length <0.49%) were associated with a
shorter keystone area length (P = 0.004). Age, gender, septal deviation
are not risk factors as they did not significantly influence keystone
area length. Conclusions: One third of our patients (31.5%) had short
KSA length < 5mm which carries higher risk of disruption to
the dorsum integrity upon complete detachment of osseo-cartilaginous
junction. We recommend preoperative CT imaging for thorough evaluation
and precise measurement of KSA. Patients with relatively shorter nasal
bones detected on examination (and confirmed radiologically), need to be
recognized as they are more likely to have shorter KSA