Frontal sinus septations predict the presence of supraorbital ethmoid cells

Correlation Analysis of the Pneumatization of the Supraorbital Ethmoid Cell and the Position of the Anterior Ethmoidal Artery

OBJECTIVES

This study aimed to measure the supraorbital ethmoid cell (SOEC) and characterize the relationship between the degree of SOEC pneumatization and the position of the anterior ethmoidal artery (AEA) in relation to the skull base.

METHODS

Computed tomography (CT) scans of 100 patients were analyzed. The correlation between the pneumatization of SOEC and the distance of the AEA from the skull base was explored by Spearman's correlation rho efficient test.

RESULTS

The distance of the AEA from skull base was 3.10 (2.60,3.60) mm in patients with SOEC compared with 0.6(0.40,2.10)mm in those without(P < .001). In 50.5% of the patients, the AEA was located below the skull base; the incidence of this localization was significantly higher in those with SOEC than in those without (78.79%vs22.77%, P < .001). Compared to female patients, male patients owned greater SOEC height (9.65vs8.20mm, P = .007). The SOECs volume (r = 0.45, P < .001), height (r = .30, P = .003), and transverse diameter (r = 0.28, P = .005) were all significantly correlated with the distance of the AEA from the skull base.

CONCLUSIONS

The pneumatization of SOEC critically impact the distance between the AEA and skull base. The higher the degree of pneumatization, the farther from the skull base the AEA will be, increasing the risk of complications during nasal endoscopic surgery. These results provide an important reference for protecting the AEA during nasal endoscopic surgery.

Multidetector CT of the Nasal Cavity and Paranasal Sinuses Variations in 73 Patients

Detailed knowledge of the anatomy of the nasal cavity and paranasal sinuses is very important in the diagnosis of pathological processes, planning of endoscopic surgery, and radiologic guiding techniques during certain operations. Observational study. Clinic of Neurosurgery, Institute and Department of Anatomy and Pathology, Clinic and Department for Otorhinolaryngology and Maxillofacial Surgery, Faculty of Medicine. Two heads with brains were serially cut in the axial and coronal planes. 73 individuals, who were enrolled among 1848 patients, underwent examination by multidetector computerized tomography. A nasal septal deviation was seen in 65.8%, and septal pneumatization in 11%. Superior concha pneumatization was observed in 1.4% of patients, middle concha bullosa in 30.2%, and its hypoplasia in 1.4%. The lamina papyracea dehiscence was also present in 1.4%. The uncinate process was absent in 1.4%, and it was pneumatized in 4.2%. Agger nasi cells were noticed in 34.3%, and Haller and Onodi cells in 20.7% each. The olfactory fossa was shallow in 9.7%, deep in 31.6%, and very deep in 58.9%. Absence of the frontal sinus was seen in 9.7%. The presellar type of the sphenoidal sinus was present in 11%, the sellar in 35.7%, and the postsellar in 53.5%. Hypoplasia of the maxillary sinus was revealed in 1.4%, and hyperpneumatization in 4.2%. The sinus floor was usually below the level (60.3%), at the same level (20.7%), or above the level of the nasal floor (19.2%). The bony septum within the sinus was seen in 52.1%. The presented data are of a great significance in order to avoid a misdiagnosis of the anatomic variations, to make a proper diagnosis of certain diseases, and for safe endonasal operations.

Anatomic Variations of Paranasal Region in Migraine

PURPOSE

To assess the incidence of anatomical variations of the paranasal region on computed tomography in migraine patients compared with control subjects.

METHODS

Paranasal computed tomography scans of 2 groups consisting of 50 migraine patients and 50 control subjects were evaluated, retrospectively. The presence of anatomic variations and the unilateral or bilateral presence of these variations were noted. Appropriate statistical tests were performed to compare the migraine and control groups, using a threshold P value of 0.05 for statistical significance.

RESULTS

The migraine group included 39 female and 11 male patients with mean age of 39.9 (range: 18-65) years. The control subject group included 29 female and 21 male patients with mean age of 41.9 (range: 18-73) years. Anatomic variations noted included nasal septal deviation and spur, paradoxical curvature of middle concha, agger nasi cell, infraorbital ethmoidal (Haller) cells, sphenoethmoidal (Onodi) cells, supraorbital ethmoidal air cells, concha bullosa, uncinate bulla, and pneumatized crista galli. Of these variations, only the presence of Haller cells was statistically significantly higher in the migraine group compared with controls (P = 0.007). The unilateral presence of Onodi (P < 0.001), unilateral presence of supraorbital ethmoidal air cells (P = 0.012), and bilateral presence of concha bullosa (P = 0.016) were statistically significantly higher in the migraine group. There was no statistically significant difference between the unilateral or bilateral presence of Haller cells in migraine patients compared with controls (P > 0.05).

CONCLUSION

Radiographic assessment of the paranasal sinuses is useful to elucidate potential points of pathology in migraine patients. The specific contribution of Haller cells to migraine headache symptoms and safe methods for surgical decompression warrant further study.

International Frontal Sinus Anatomy Classification and anatomic predictors of low-lying anterior ethmoidal arteries

BACKGROUND

The International Frontal Sinus Anatomy Classification (IFAC) was introduced to more accurately characterize ethmoid and frontal sinus pneumatization patterns. The prevalence of IFAC cells and their anatomic associations have not been described.

OBJECTIVE

The goal was to examine the prevalence of IFAC cells and determine radiologic features associated with a low-lying anterior ethmoidal artery (LAEA).

METHODS

Imaging of adult patients who underwent computed tomographies from January 2015 to March 2016 were retrospectively reviewed by using the IFAC classification. We also measured the distance from the skull base to the anterior ethmoidal artery (AEA), the height of the lateral lamella of the cribriform plate, and anterior-posterior diameter from the anterior wall of the frontal sinus to the skull base (APF). Patients with a history of sinus surgery, trauma, malignancy, or congenital anomaly were excluded. Statistical analysis was performed by using Pearson correlation coefficients and χ2 tests.

RESULTS

A total of 95 patients met the inclusion criteria. There was a significant association between supraorbital ethmoid cells and an LAEA (p < 0.001), with a significant effect size (φ = 0.276, p = 0.007). An inverse relationship was observed between Keros type I classification I and an LAEA (p < 0.001), with a significant effect size (φ = -0.414, p = 0.000). Significant associations were found between the AEA distance from the skull base and the cribriform lateral lamella height (R = 0.576, p < 0.001). In addition, there was a significant association between the AEA distance from the skull base and the APF (R = 0.497, p < 0.001).

CONCLUSION

The presence of a supraorbital ethmoid cell and a wide APF were associated with an LAEA. There was a significant relationship between Keros type I classification and the AEA adjacent to the skull base. Delineation of these anatomic relationships may be helpful during endoscopic sinus surgery to avoid complications.

Diagnostic Performance of Multidetector Computed Tomography (MDCT) in Diagnosis of Sinus Variations

Background

In this prospective study, we looked for correlations between anatomic variants of paranasal sinuses and chronic or recurrent sinusitis.

Material/Methods

Two hundred and forty (240) patients with clinical features of chronic rhinosinusitis were examined; patients with first-onset or allergic sinusitis and pregnant females were excluded. Routine multi-slice CT of the paranasal sinuses was performed to look for mucosal disease of the paranasal sinuses, drainage pathways, and presence of anatomical variations and their relation to known sinus drainage pathways.

Results

Anatomic variations were very frequent, and we classified them into four easily recognized groups: nasal septum variations, middle turbinate variations, uncinate process variations, and ethmoidal variations. Deviated nasal septum was the most frequent variation in patients with chronic or recurrent sinusitis, and it was detected in 48.8% of cases. Agger nasi cells and concha bullosa were equally frequent (30.6%), and Haller cells were detected in 11.2%. Uncinate process variations were detected in 18.1%, and the large ethmoid bulla was detected in 10%.

Conclusions

The importance of anatomic variations is that they can compromise drainage pathway of the related sinus, which results in inflammatory sinus disease. Anatomical variations are not diseases on their own and may be present as incidental findings in patient with chronic sinusitis.

Virtual Mapping of the Frontal Recess: Guiding Safe and Efficient Frontal Sinus Surgery

Objective To define relationships between the frontal sinus opening, ostia of other frontal recess cells, and endoscopic landmarks and to develop a clinically useful framework to guide frontal sinus surgery. Study Design Retrospective review. Setting Tertiary care academic referral center. Methods Adult patients with computed tomography (CT) without sinonasal pathology were included. Virtual endoscopy (using OsiriX) and corresponding CT reconstructions were used to identify all visible ostia in the frontal recess and characterize their positions in spaces between the uncinate/agger nasi (U), bulla ethmoidalis (EB), and middle turbinate (MT). Results Two hundred sides in 100 patients (median age 51 years, 62% female) were analyzed. The "center" of each map was defined as the intersection of spaces between U, EB, and MT. The frontal sinus opening was in the "center" in 53% of frontal recesses, lateral to this position in 29%, and anterior in 11%. When the frontal sinus opening was at the "center," anterior ostia drained frontal Kuhn T cells in 51% and intersinus septal cells in 23%. The skull base attachment of the apical strut of the uncinate process demarcated medial and lateral within the space between U and EB, with the opening to the frontal sinus medial in 68% and lateral in 31%. Left-right asymmetry in frontal sinus openings was noted in 46% of patients. Conclusion Combining preoperative imaging and knowledge of these anatomic relationships may facilitate more efficient frontal outflow tract identification and instrumentation. This represents the first and largest description of ostial configurations relative to endoscopic structural landmarks.

LEVEL OF EVIDENCE

4.

Computed Tomographic Analysis: The Effects of Frontal Recess Morphology and the Presence of Anatomical Variations on Frontal Sinus Pneumatization

The aim of this study is to describe the morphology of frontal recess area with its anatomical variations and to reveal if frontal recess morphology and the anatomical variations related to that region have effects on the pneumatization of the frontal sinuses. The frontal sinus and recess morphometry of 136 sides of 68 dry skulls were evaluated on multislice high-resolution computed tomography. The relationships between frontal sinus and frontal recess measurements were analyzed by correlation and linear regression analysis. The variables between the groups of anatomical variations were analyzed by Mann-Whitney U test and χ test or Fisher exact test. A positive relationship between the sagittal length of spina nasalis interna and morphometric measurements of frontal sinus was revealed (P <0.05). Agger nasi cells were present in 64.2% of sides, supraorbital ethmoid cells (SOECs) in 19.6%, type 3 frontal cells (FCs) in 18.9%, suprabullar cells in 24.3%, and frontal bulla was noted in 5.4%. Intersinus septal cells were observed in 16.2% of the skulls. There were statistically different increases in the measurements of frontal sinus morphometry in the presences of SOECs and type 3 FCs (P <0.05). The diameter of frontal sinus ostium was decreased in the presences of AN, SOEC, type 3 FC, and supraorbital ethmoid cell statistically (P = 0.049, P = 0.029, P = 0.043, P <0.001 respectively). In conclusion, frontal sinus pneumatization was affected by the spina nasalis interna and the presence of anatomical variations related to frontal recess or ostium region instead of the morphology of that area.

CT of Anatomic Variants of the Paranasal Sinuses and Nasal Cavity: Poor Correlation With Radiologically Significant Rhinosinusitis but Importance in Surgical Planning

OBJECTIVE

The purpose of this study was to determine the incidence of sinonasal anatomic variants and to assess their relation to sinonasal mucosal disease.

MATERIALS AND METHODS

A retrospective evaluation of 192 sinus CT examinations of patients with a clinical history of rhinosinusitis was conducted. The CT scans were evaluated for the presence of several anatomic variants of the sinonasal cavities, and the prevalence of each variant was calculated. Prevalences of all sinonasal anatomic variants were compared between patients who had minimal to no apparent imaging evidence of rhinosinusitis and those who had radiologic evidence of clinically significant rhinosinusitis.

RESULTS

The most common normal variants were nasal septal deviation, Agger nasi cells, and extension of the sphenoid sinuses into the posterior nasal septum. We found no statistically significant difference in the prevalence of any of the studied anatomic variants between patients with minimal and those with clinically significant paranasal sinus or nasal cavity disease.

CONCLUSION

Analysis of every routine CT scan of the paranasal sinuses obtained for sinusitis or rhinitis for the presence of different anatomic variants is of questionable value unless surgery is planned.