Intranasal landmarks for adequate L-strut preservation during endoscopic septoplasty

A 10- to 15-mm L-strut in the dorsal and caudal areas of the nasal septum is preserved during septoplasty to maintain structural stability and prevent external deformity. However, during endoscopically performed septoplasty the surgeon has a very different perspective, which may create a more challenging situation to ensure adequate strut preservation. No reliable intranasal landmarks have been established. We establish intranasal landmarks that may be used during endoscopic septoplasty (ES) to safely maintain sufficient caudal and dorsal support. A cadaveric anatomic study was performed.

Measurements were made using calipers in 15 human cadavers (8 male and 7 female subjects), totaling 30 nasal passages. The caudal strut distance was measured from the inferior concha to the caudal aspect of the quadrangular cartilage. The dorsal strut height was measured from a line parallel to the nasal dorsum that extended from the middle turbinate (MT) axilla to the nasal vestibule (termed the "axillary line").

Using the inferior concha and the vertical MT attachment as endoscopic landmarks, the average caudal and dorsal struts measured 18.9 and 16.4 mm,, respectively. Strut size was larger in male subjects than female subjects; however, dimensions remained >10 mm in all cadavers, establishing these landmarks as safe and effective for determining extent of cartilage resection.

The inferior turbinate and vertical MT attachment may be used to guide the extent of cartilage resection during ES. Use of the described conchal and axillary lines as landmarks allow for preservation of an adequate L-strut during ES and may reduce support related complications.