Role of Anatomic variations of Uncinate Process in Frontal Sinusitis

The Upper Attachment of the Uncinate Process and Anterior Ethmoidal Artery

OBJECTIVE

Variations in the upper attachment of the uncinate process (UP) are important because they can affect frontal sinus drainage and change the morphology. Functional endoscopic sinus surgery (FESS) is the primary technique used to treat chronic medically refractory rhinosinusitis. Uncinectomy is the basis of FESS technique to obtain the best possible result from surgery. The anterior ethmoidal artery (AEA) enters the nasal cavity through the orbital medial wall (lamina papyracea) may also be affected by the upper attachment of the UP. The aim of this study was to investigate a possible link between UP variations and the course of the AEA.

MATERIALS AND METHODS

This retrospective, computed tomography (CT)-based, anatomic study was conducted on 200 healthy adults (100 females and 100 males) by screening bilateral paranasal sinus images. The upper attachment of the UP was classified in 6 types (1-6) based on the Liu classification. The AEA was divided into 4 types (A-D) based on location: anterior to the frontal sinus (A), between the frontal sinus and the middle nasal turbinate (B), and anterior to the posterior ethmoidal cells (C and D). All the CT images were evaluated simultaneously by 2 anatomists and 1 radiologist.

RESULTS

Of the total cases (200 right and 200 left side), 48.8% were type 1 UP attachment, 11.0% type 2, 12% type 3, 9% type 4, 18% type 5, and 1.2% type 6. The AEAs were classified as 12.2% type A, 71.8% type B, 15.2% type C, and 0.8% type D.

CONCLUSION

The course of the AEA through the nasal cavity was observed to shift anteriorly from the ethmoidal bulla to the frontal sinus in patients with UP attached to the lamina papyracea and middle turbinate. Remarkably, the AEA always coursed anterior from the middle nasal turbinate line.

Osteomyelitis of Frontal Sinus: A Rare Sequelae of Acute Bacterial Sinusitis Associated With Anatomical Variations in the Frontal Sinus Drainage Pathway

Frontal osteomyelitis is characterized by localized osteal inflammation of the frontal bone. This is a rare complication of acute frontal sinusitis. The present case is being reported to highlight the likely role of anatomical variations in frontal sinus drainage pathways in the causation of this complication apart from other known predisposing factors like young age and immunocompromised state. The patient initially presented with seizures, fever, and headache and was diagnosed with viral encephalitis. However, the symptoms gradually progressed to cause right eye swelling and an increase in the severity of headache without any nasal complaints. Diagnostic nasal endoscopy revealed mucopurulent secretions in both nasal cavities. Computed tomography and magnetic resonance imaging diagnosed the anatomical variations, the extent of sinus involvement, and frontal osteomyelitis. Antimicrobial therapy for an extended duration of four weeks, along with functional endoscopic sinus surgery resulted in excellent outcomes.

Anatomical Variants of the Uncinate Process: A Challenge in the Endoscopic Surgery of the Nose and Paranasal Sinuses

Importance To identify the anatomical variants of the uncinate process relevant to surgical intervention during the nose and paranasal sinus surgeries. Objective To evaluate the frequency of anatomical variants of the uncinate process in a population of northeast Mexico and compare it with another population. Methods Retrospective study, descriptive and analytical, randomly selected patients with radiological evaluation at Hospital Universitario Dr. José Eleuterio González, Monterrey, Mexico. Images were obtained from the Radiology Department. A total of 149 patients aged from 18 to 79 years with paranasal sinus-CT performed between January 2019 and December 2021 were analyzed. The variables evaluated were uncinate process anatomical variations by age group, radiological classification of the superior attachment of the uncinate process, and morphological variations. Main outcomes and measures The primary study outcome was the determination of the most frequent insertion of uncinate process in the northeast Mexican population. Results The 149 CT scans comprised 71 females with a mean age of 38.28 ± 16.7 years and 78 males, with a mean age of 41.8 ± 15.01 years. The most frequent uncinate process of superior attachment was type one, observed in 57.7% of males (n=45) and 50.7% of females (n=37) (p=0.494). Type one was most observed on the right side (57.7%). Type four was the second most common type, present in 12.8% of males (n=10) and 12.7% of females (n=9) (p=0.82). Conclusion Knowledge about the types of variations in the insertion of the uncinate process is fundamental prior to any endoscopic sinus surgery. The surgeon must be familiar with this detail when approaching patients with sinonasal pathology.

Computed Tomographic Comparison of Length, Width and Angulation of Ethmoidal Infundibulum in Patients With and Without Maxillary Sinusitis

Ethmoidal infundibulum (EI) is an important part of the osteomeatal complex, which provides the main pathway for the maxillary sinus drainage. This study aimed to compare the length, width, and angulation of EI in patients with/without maxillary sinusitis using computed tomography (CT). This cross-sectional study evaluated 818 spiral CT scans of patients with/without maxillary sinusitis (n = 409 maxillary sinuses in each group) classified according to the clinical symptoms and the Lund-Mackay score for mucosal thickening. The degree of mucosal thickening (on axial and coronal sections), anatomical variations namely concha bullosa (CB), ethmoidal bulla (EB), and Haller cells (HCs), the form of EI (on coronal sections), the length, width and angulation of EI, and degree of nasal septal deviation (on coronal sections) were all evaluated. Data were analyzed by parametric and non-parametric tests (alpha = 0.05). The frequency of EB (P < 0.001), EI form (P < 0.001) and HC (P = 0.011), and the length and width of EI (P < 0.001) were significantly different in patients with and without maxillary sinusitis. The length and width of EI were significantly correlated with the degree of mucosal thickening (P < 0.01). The frequency of CB (P = 0.002), EB (P < 0.001), and HC (P = 0.002), and the EI form (P < 0.001) were significantly different in groups with different degrees of mucosal thickening. EI was wider and shorter in patients with maxillary sinusitis. By an increase in mucosal thickness, the length of EI decreased while its width increased. Also, the frequency of EB and HC, and the EI form were significantly different in the two groups.

Relationship between the Superior Attachment of the Uncinate Process and Pneumatization of the Middle Turbinate—A Radiological Study

Objective: the superior attachment of the uncinate process (SAUP) is highly variable. Lateral types of SAUP are associated with frontal rhinosinusitis. SAUP in the middle turbinate is more common when the middle turbinate is aerated. We aim to refine these findings by studying the relationship between the SAUP type and the different subtypes of pneumatization of the middle turbinate. Methods: 200 CT sinonasal scans were analyzed by an otolaryngologist and a radiologist. All CT scans were analyzed to study the type of the middle turbinate concha bullosa and lamellar cell and the type of SAUP. Results: 379 sides were analyzed. The prevalence of the various types of SAUP were: Type I: 43.80%, Type II: 22.16%, Type III: 16.36%, Type IV: 3.69%, Type V: 9.76%, and Type VI: 4.22%. When studying the pneumatization of the middle turbinate and the SAUP types, we only found a statistically significant association between the lateral attachment of the uncinate process and the presence of a lamellar cell (p = 0.029). Conclusion: lateral types of SAUP are more likely in the presence of a lamellar cell. This finding, therefore, renders checking for lateral SAUP types in the presence of a lamellar cell even more relevant than when studying the pre-surgical CT scan. In those cases, it is advisable to perform a careful and complete uncinectomy.

[The investigation of the histological differences between the mucosa on the nasal and sinus sides of uncinate process of chronic rhinosinusitis]

Objective:The aim of this study is to check whether histopathological differences exist between the nasal side and the sinus side of uncinate process of chronic rhinosinusitis and the histopathological basis of nasal polyp was discussed. Methods:The uncinate processes of chronic rhinosinusitis and control subjects were enrolled from October 2016 to April 2017. The following histopathological data were assessed: height of basement membrane, the proportion of glands in the sub-epithelium, the numbers of goblet cells and inflammatory cells. Results:A total of 116 patients were recruited, including 38 chronic rhinosinusitis with nasal polyps（CRSwNP）, 58 chronic rhinosinusitis without nasal polyps（CRSsNP） and 20 controls. There was no significant difference between age and gender distribution（P>0.05）. The basement membrane was significantly thinner on the sinus side of the 3 groups' uncinate processes than on the nasal side except CRSwNP group（P<0.05）. The basement membrane of CRSwNP and CRSsNP was significantly higher than control uncinate processes（P<0.05）. Inflammatory cells number were significantly increased in CRSwNP and CRSsNP than in the control uncinate processes, and the nasal side was obviously more than the sinus side in the CRSwNP and CRSsNP groups（P<0.05）. The number of goblet cells was more on the sinus side of the 3 groups uncinate processes than on the nasal side, that of CRSsNP and control were significant difference between the nasal side and sinus side（P<0.05）. The proportion of glands was larger on the sinus and nasal side of the uncinate processes in CRSwNP and CRSsNP than that of the control uncinate processes（P<0.05）, and the proportion of glands was significantly greater on the nasal side than on the sinus side of the uncinate processes in CRSwNP（P<0.05）. Conclusion:Histopathological differences exist between the nasal side and sinus side of the ups of CRSwNP, CRSsNP and control. The nasal side is more prone to polyps than the sinus side, which may be related to the thickening of basement membrane, the increase of inflammatory cells and gland area, and the decrease of goblet cells.

Association between the insertion type of the uncinate process and the development of Frontal Sinus Mucoceles - is there a relationship?

BACKGROUND

The frontal sinus drainage pathway is formed by either the ethmoid infundibulum or the middle meatus, which depends on the superior insertion of the uncinate process. According to Landsberg & Friedman the are 6 types of superior uncinate process insertion. The aim of this study is to find an association between the uncinate process insertion type and the development of frontal sinus mucoceles.

METHODS

Fifty sinus CT scans were analysed. Exclusion criteria were previous nasal surgeries, malignancy, polyposis and an insufficient image quality. Superior insertions of the uncinate process were analysed according to the Landsberg & Friedman classification. The results were tabulated and analysed using SPSS 25.0.

RESULTS

The analysis revealed type 1 insertion in 6% of the CT scans, type 2 in 32%, type 3 in 26%, type 4 in 0%, type 5 in 28% and type 6 in 8%. Despite 44% of the CT scans with frontal sinus mucocele showing a type 2 insertion of the uncinate process, both the Chi-Square test and the Cramer's V test showed no statistical significance (p>.05). Logistic regression also showed that uncinate process insertion type does not influence the likelihood of development of frontal sinuses mucoceles.

CONCLUSIONS

The insertion of the uncinate process does not influence the development of frontal sinus mucoceles.

Anatomic Variations of Ethmoid Roof and Risk of Skull Base Injury in Endoscopic Sinus Surgery: Statistical Correlations

BACKGROUND

Recent developments in endoscopic sinus surgery (ESS) have increased the need to investigate the complex anatomic variations in the ethmoid roof and skull base, to inform the surgeon about the risk of damaging these crucial areas during ESS.

OBJECTIVE

To offer a detailed description of sinus anatomy focusing on the key surgical landmarks in ESS and frontal recess surgery to standardize a systematic approach during the preoperative sinuses imaging evaluation.Methodology: A total of 220 computed tomography (CT) scans were reviewed to obtain six sets of measurements: the depth of the cribriform plate (CP); the length of the lateral lamella of the cribriform plate (LLCP); the angle formed by the LLCP and the continuation of the horizontal plane passing through the CP; the position of the anterior ethmoidal artery (AEA) at the skull base; the extent of frontal sinus pneumatization (FSP); the type of superior attachment of the uncinate process (SAUP).

RESULTS

The length of the LLCP was statistically significantly correlated with the different Keros classification types, the angle formed by the LLCP with the continuation of the horizontal plane passing through the CP, and with the AEA position at the skull base. The depth of the olfactory fossa was correlated with FSP.

CONCLUSIONS

According to the Keros and Gera classifications, the data obtained from these evaluations allow the assessment of anatomic-radiological risk profiles and can help identify those patients who are high risk for ethmoid roof injury.

Endoscopic frontal recess anatomy directed by the drainage pathways using the connecting plates as landmarks

PURPOSE

To investigate the anatomical features of frontal recess (FR) drainage, and the classification of FR cells and frontal sinus (FS).

METHODS

Fifty sides from 30 adult cadaver heads were examined. FR cells and FS along the drainage pathways were dissected under 0° and 70° endoscopic views using unique connecting structures between the uncinate process and the ethmoid bulla as landmarks.

RESULTS

Connecting plates between the uncinate process and the ethmoid bulla were discovered and termed medial suprainfundibular plate (MSIP), which were observed on each cadaver head, and lateral suprainfundibular plate (LSIP) on 92% (46/50) sides. Separated by MSIP, two drainage pathways were identified and named medial pathways of the FR (MPFR) medial to the MSIP and the lateral pathways of the FR (LPFR) in the lateral side. Different drainage pathways of the FS were confirmed, in which drained into the MPFR in 37 and into the LPFR in 13 of the cadaver sides.

CONCLUSIONS

MSIP is the critical landmark for the recognition of MPFR, LPFR, and the classification of FR cells. The FR resection along LPFR and MPFR facilitated excellent exposure of FS.