Nasal septal body has been described in the literature using numerous terms as swell body (SB), the septal turbinate , the septal cavernous body ,septal erectile tissue. Despite these many names, its exact role in nasal airway physiology has not been sufficiently studied.
The nasal septal swell body is known as the thickest part of nasal septum and it is closely related to internal nasal valve region which is the narrowest portion of the nasal cavity in the nasal valve region; therefore, any changes in volume of the nasal septal body may cause nasal obstruction.
This study has been conducted on twenty (20) patients from those attending the ENT outpatient clinic of Benha University hospitals and suffering from nasal obstruction due to deviated nasal septum with or without hypertrophied inferior turbinate, aged 18-49 years( mean age 33.5 y.) and was conducted between March 2016 and December 2016.
After proper preoperative evaluation through detailed history and examination by anterior rhinoscopy and by rigid nasal endoscopy and full investigations done to all patients also CT scan of the nose and paranasal sinuses to determine the thickness and location of the Nasal Septal Body(NSB) in both coronal and axial sections.Patients with acute sinusits or polyposis or previous nasal surgery or systemic uncontrolled disease like diabetes or hypertension were excluded from our study.
Under general anesthesia ,unilateral biopsies of the nasal septal body(from the side which shows compensatory hypertrophy), and the adjacent inferior turbinate have been obtained and processed and routinely were stained routinely with hematoxylin- eosin; representative sections were also stained with Masson's trichrome stain to allow better differentiation of stromal elements from smooth muscles also stained with Periodic acid–Schiff stain (PAS) to give better recognition of glandular tissue, The mean area % of collagen fibers deposition and PAS +ve reaction, were quantified.
Areas for further electron microscopic examination were chosen and the blocks trimmed .Ultra-thin sections were cut, collected on copper grids, and stained with 4% uranyle acetate and lead nitrate then sections were examined and electron micrographs were taken using transmission electron microscope(T.E.M) ,electron micrographs were obtained for qualitative assessment.
The nasal septal body is covered by pseudostratified columnar ciliated epithelium with goblet cells,the epithelium of septal body shows tall columnar cells and shows some invaginations mostly to increase surface area withthickened basement membrane also inferior turbinate is covered by pseudostratified columnar ciliated epithelium with goblet cells less crowded and thinner than that of the septal body, no invaginations are seen and thinner basement membrane.
Submucosa of nasal septal body is rich in seromucinious glands and venous sinusoids. Branching seromucinious glands are noticed reflecting high secretory functions of these glands but these glands are less numerous in inferior turbinate and also venous sinusoids are less in number and smaller than that of septal body. Submucosa of the inferior turbinate has been observed containing well developed fibrous stromamorethan that of the septal body.
Sections stained with Masson's trichrome and PAS show that Inferior turbinate having a prominence of collagen fibers with a mean proportion of 26.58%,in contrast to the septal body(SB), which had 13.76%.Septal swell body was found to have a prominence of glandular tissues with a mean proportion of 19.89%, in contrast to the IT, which had 7.89%.
At ultrastructural level, epithelial cells of septal body have large number of cilia and microvilli at their free border and with obviously noted intra-epithelial goblet cells (full with mucus)and are closely opposed to its neighbours ,the junctional complex between the cells are tightly sealed zone (tight junction), while the inferior turbinate mucosa shows lesser number of cilia implanted in the apical surface than that of septal body epithelial cells, tight junctions are slightly disrupted than that between septal body epithelial cells.
The submucosa of both septal body and inferior turbinate shows wide range of ultrastructural similarity and inflammatory cell infiltrate and it is noticed that the extracellular matrix of the inferior turbinate shows more well-arranged collagen fibers than that of the nasal septal body.
This study confirms the presence of venous sinusoids and abundant seromucinous glands in the nasal septal swell body and its histological and ultrastructural similarity to the inferior turbinate which demonstrate its significant role in humidification of the inspired air and controlling nasal air flow and nasal airway resistance. This should guide us to surgically reduce the volume of nasal septal body for treatment ofcertain nasal airway obstruction cases.
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