Histology of inferior turbinate vascularity: A cadaveric study

BACKGROUND: The inferior turbinate which plays an important role in nazal physiology and it consists dynamic component of the nazal valve that is the narrowest part of the upper aerodigestive tract, and its pathologies are the common cause of the nazal obstruction. The histology, anatomical variations, glandular pattern and vascularity of these erectile structures on the lateral wall of the nazal cavity had been the subject of many investigations. In these studies, in which erectile structures and vascularity were evaluated, it was shown that blood flow in the posterior one-third of the turbinate increased. Majority of these datas are obtained from the evaluation of the materials which was gathered from nazal surgeries. The aim of this study is to evaluate the whole turbinate in the terms of the vascular structures histologically from the anterior to posterior and to determine regional differences, if any. MATERIALS AND METHODS: 13 inferior turbinates those were resected from 8 fresh frozen cadavers which gathered from Ege University Anatomy Department. Inferior turbinates are included those are suitable for histological preparation. Turbinates were separated into two groups; 7 right and 8 left turbinate. The resected turbinates are prepareted acid and alcohol and than were embedded in paraffin blocks. Each turbinate was divided into 3 main parts, anterior to posterior, 0.5 micron serial sections were viii evaluated. 10 sections were obtained from each one third of the turbinate, anterior, posterior and middle of the turbinate, and 30 sections in total were evaluated and these were stained with Hematoxylin & Eozin, Masson Trichrome and PAS. On the light microscope, large and enlarged arteries and veins were counted and the anterior, middle and posterior groups were collected. One way ANOVA test was applied in SPSS 21 software. In addition, two separate groups were created for the lateral and medial sides of the bone, and the arterial and venous structures were counted in all sections. Diameters of arteries were measured and the mean diameter in the each turbinate section were calculated by x10 magnification. RESULTS: In the anterior 1/3, the mean value for arterial sections was 33.25 (Min: 9, Max: 105, SD: 33.24, IR: 41), the mean value for venous sections were 308 (Min: 124; Max: 674; SD: 181,347; IR: 255). in the middle 1/3, mean values for arterial sections were 56,13 (Min: 16, Max: 158, SD: 52,179, IR: 79), mean values for the venous sections were 663,63 (Min: 179, Max: 1906; SD: 584,502; IR: 702). In the posterior 1/3, mean values for arterial sections were 35.63 (Min: 1, Max: 88, SD: 27.045, IR: 37), mean values for venous sections were 445.88 (Min: 88, Max: 819, SD : 269,683; IR: 546). Statistical analysis with one way ANOVA showed that the difference between the regions for venous structures in the anterior, middle and posterior 1/3 regions was p> 0.05 (= 0.202) and for arterial structures was p> 0.05 (= 0.449) ix DISCUSSION: Since 1940s, researches about the inferior turbinate, which is one of the corner stone in nazal physiology, still continue. Particularly, studies on how this erectile structure performs its function have been focused on glandular epithelium and vascular structures. In these anatomical studies, it was emphasized that vascularisation of posterior one-third is much more than anterior part of the turbinate and vascularisation is the most pronounced within the tail of the turbinate. However, in 2004, Philpott et al. conducted a CD34 immunohistochemistry study on tissue biopsies that different regions of the nazal cavity were taken from patients who underwent endoscopic sinus surgery. In this study, regional differences in microvascular structures was not seen. In our study, in the full-layer serial sections obtained from the whole turbinate, the arterial and venous structures were evaluated by light microscopy and it was compared whether there was any difference in the vascular structure in the anterior, middle and posterior groups. There has not been found any statistical differences between the distribution of the vascular structures of the inferior turbinate in the anterior, middle or posterior part. Unlike what is known about turbinate surgery complications, according to our study, it can be considered that bleeding can occur whichever part of the turbinate is operated. Further studies including surface area and vessel diameters are needed to evaluate the vascular pattern and to guide future surgical procedures, however.