Anterior Clinoid Process Pneumatization Research Articles

Unravelling the Complex Relationship Between Frontal Sinus Pneumatization and Paranasal Sinus Anatomical Variants: Insights from CT Imaging.

The aim of this study was to analyse the relationship between frontal sinus pneumatization and its effect on various variations of paranasal sinuses on paranasal sinus CT scan. A total number of 100 patients (51 males, 49 females) were included in this study. Patients were divided into three groups on the basis of their frontal sinus pneumatization extent on paranasal sinus CT as Type 1 pneumatization (aplasia and hypoplasia), Type 2 pneumatization (medium) and Type 3 pneumatization (hyperplasia). The prevalence of various variations like pneumatization of upper and middle turbinate, presence of agger nasi, Haller and Onodi cell, maxillary sinus hypoplasia, extent of sphenoid sinus pneumatization, pneumatization of anterior clinoid process, pterygoid process and greater wing of sphenoid sinus, dehiscence and protrusion of internal carotid artery and optic nerve types were ascertained and compared within each group. The prevalence of Onodi cell, anterior clinoid process and greater wing of sphenoid pneumatization and optic nerves type 3 and 4 were higher in Type 3 frontal sinus pneumatization group as compared with other groups. Excessive pneumatization of frontal sinus has various effects on paranasal sinus variations. Surgeons dealing with endoscopic sinus surgery, maxillofacial and skull base surgery must be vigilant of association between these variations preoperatively for avoiding complications.

Minimally Invasive Posterolateral Transcavernous Transtentorial Approach: 2-Dimensional Operative Video.

MIPLATTA uses a "key-exposure" concept aligning a small minipterional craniotomy with variations of extradural transcavernous transtentorial corridors to access the skull base. Safety and efficiency depend on mastery of the anterior clinoid process (ACP) and cavernous sinus (CS). Preoperative planning includes assessment of ACP pneumatization; tumor epicenter relative to the CS, ACP, and tentorium; and pattern of venous drainage (role of vein of Labbé). 1. Interfascial flap for facial nerve preservation.2. Minipterional craniotomy with extradural anterior clinoidectomy.3. Variable Transcavernous dissection according to the Hakuba method4. Dural opening parallel to the Sylvian fissure.5. Transtentorial with possible Kawase.6. Closure with autologous graft into the clinoidal triangle and water-tight dural closure. Incomplete release of the optic and oculomotor nerves during anterior clinoidectomy may lead to deficits. Insufficient caudal extent of the craniotomy may cause undue retraction on Labbé and a temporal lobe infarct. Thorough anatomic knowledge of the CS is a key for catastrophe prevention. 1. Basic MIPLATTA with minipterional and extradural anterior clinoidectomy (Hakuba approach) for optic nerve decompression and parasellar lesions.2. Extended MIPLATTA adds oculomotor nerve transposition and cavernous sinus peeling for middle fossa, sphenoid ridge, and giant clinoid tumors.3. Full MIPLATTA adds Kawase and internal auditory canal exposure with endoscopic-assisted microsurgery for tumors invading the posterior fossa.The patients consented to both surgery and publication of their images. Permission was obtained appropriately for the publication of the cadaveric images. The anatomic images and animations in the surgical anatomy section of the video are sole property of www.neurosurgicalanatomy.com and Neurosurgical Anatomy by Arnau Benet, MD, who shall retain copyright, and used with permission.

Prevalence of Anatomical Variations of Sphenoid Sinus and Its Adjacent Structures Pneumatization and Its Significance: A CT Scan Study.

The purpose of our study was to assess the prevalence of variations and type of sphenoid sinus and its adjacent structures pneumatization and its significance. This prospective study included 114 patients who underwent CT of the paranasal sinuses. The CT scan in axial, coronal and mid sagital section were analysed to assess the type of pneumatization of the sphenoid sinus and its adjacent structures like; anterior clinoid process, greater wing of sphenoid and pterygoid process. The sphenoid sinus pneumatization was classified into Conchal, Presellar, and Sellar types, later comprised of sellar and post-sellar types. Out of 114 cases of pneumatized sphenoid sinus, 5.2% cases were conchal type, 26.3% cases Presellar type and 68.4% cases sellar type. The one or more adjacent structures was pneumatized in 71 (62.2%) of cases. The adjacent structures which found to be pneumatized are anterior clinoid process in 26.3%, Pterygoid process in 23.6%, and greater wing of sphenoid in 12.3% cases. The pneumatization of adjacent structures was more prevalent in sellar type of sphenoid sinus, followed by pre-sellar type and no pneumatization in conchal type. The anterior clinoid process pneumatization was present in 26.1% of cases, in which 3 (2.6%) cases in pre-sellar type and 27 (23.5%) cases in sellar type. It was unilaterally pneumatized in 13 (11.4%) and bilaterally in (17 (14.9%) cases. The pterygoid process pneumatization was present in 27 (23.6%) of cases, unilateral in 16 (14%) cases and bilateral in 11 (9.6%) cases. The Greater wing of sphenoid pneumatization was found in 14 (12.3%) cases, no cases in conchal types, 2 (1.8%) in pre-sellar type, and 12 (10.4%) in sellar type There was no statistically difference found in between right and left side of sphenoid sinus and its structure pneumatization. The extent of pneumatization of the sphenoid sinus has clinical and surgical implications in sinus diseases, sellar and central skull base lesions.

Anatomical Variations of the Optic Nerve in the Sphenoid Sinus: Do Ethnic Variations Matter?

There are several variations in the anatomical relations of the optic nerve with the sphenoid sinus. Proper understanding of these variations is clinically important to minimize injuries associated with surgical procedures that involve the sphenoid sinus. CT scans of paranasal sinuses obtained prior to any endoscopic surgery in the sphenoid sinus area is useful for designing operative strategies. Ethnic variations in sinonasal anatomy have been documented. The objective was to study the pattern of relationship between optic nerve and the sphenoid sinus using computerized tomographic imaging in a north Indian population, to compare our findings with previous studies in different ethnic groups and find out if ethnic variations in such a relationship matter. A prospective study was conducted on 300 patients who underwent computed tomography of the paranasal sinuses from Sept 2020 to June 2021. Relationship of optic nerves to the sphenoid sinuses was categorized according to DeLano classification. Pneumatization of the anterior clinoid process and bony dehiscence of optic nerve was also observed. Type 1 position of optic nerve was seen in 69.3%, Type 2 in 20.9%, Type 3 in 3% and Type 4 in 6.8% of sinuses. The pneumatization of anterior clinoid process (ACP) was observed in 10.5% and the bony dehiscence of optic nerve was noted in 6.5% sinuses. Bony dehiscence of optic canal had associated ACP pneumatization in 64.1% sinuses.The variability of the relation of optic nerve to the sphenoid sinus even in the persons of same ethnicity precludes a definite role of ethnicity in these variations. Other factors possibly contributing to such a relationship have been discussed.

Assessment of the Anterior Clinoid Process and Optic Strut in Chiari Malformation Type I: A Computed Tomography Study.

Objective This study aimed to evaluate morphological features of the anterior clinoid process (ACP) and the optic strut (OS) in Chiari malformation Type I (CM-I). Methods The study universe consisted of computed tomography images of 41 CM-I patients and 45 normal subjects. Comparison of the parameters for CM-I and the control group was performed with the Student's t -test. A " p < 0.05" was accepted as the significance level. Results ACP length was smaller in CM-I than the control group ( p < 0.001). In contrast to ACP length, ACP angle ( p < 0.001), OS length ( p = 0.022), and the distance between ACP and OS ( p = 0.020) were found greater in CM-I in comparison to the control group ( p < 0.05). ACP width ( p = 0.233) and OS width ( p = 0.376) were similar in both groups. ACP pneumatization in CM-I group was found as 12.20%, whereas in the control group as 8.90%. Two different types about the pneumatization were identified in CM-I group (Type 1: 4.9% and Type 2: 7.3%), whereas three different types in the control group (Type 1: 3.3%, Type 2: 4.4%, and Type 3: 1.1%). Relative to ACP, three different types about OS position were identified in CM-I group (Type C: 31.70%, Type D: 64.60%, and Type E: 3.70%) and the control group (Type C: 7.80%, Type D: 64.40%, and Type E: 27.80%). Conclusion Shorter ACP, wide-angled ACP, longer OS, and more anteriorly located OS were found in CM-I group compared with the normal group. Our findings showed that the pneumatization of ACP was not affected by CM-I.

Correlation between Pneumatization Variants of Paranasal Sinuses and Skull Base and Spontaneous Cerebrospinal Fluid Rhinorrhea: A Case-Control Study

Introduction: Spontaneous cerebrospinal fluid rhinorrhea (SCSFR) is the most common type of cerebrospinal fluid leakage and may cause serious cerebral complications. The aim of this research was to investigate the relationship between the degree of pneumatization variants of the paranasal sinus and skull base and the incidence of SCSFR. Methods: In total, 131 patients with SCSFR were analyzed, and 50 patients suffering from the nasal septal deviation were selected as controls. The pneumatization of the paranasal sinus and skull base was observed by CT scan. Results: Among the 137 fistulas, 55 (40.15%) were found in the ethmoid sinus. The incidences of Onodi cells (27.27 vs. 8%) and type 3 lateral recess of the sphenoid sinus (LRSS, 70.37 vs. 22%) in the SCSFR subgroups were significantly higher than those in the control group (p < 0.05). Moreover, the occurrence of SCSFR was linearly correlated with the classification of Onodi cells and LRSS (p < 0.05). There was no significant difference in the incidence of frontal cells, anterior clinoid process pneumatization, and posterior clinoid process pneumatization between the SCSFR patients and the controls. Conclusion: The most common site of SCSFR is the ethmoid sinus. The excessive pneumatization of the Onodi cell and LRSS increases the risk for the occurrence of SCSFR in the ethmoid sinus and sphenoid sinus, respectively. The possible association between the paranasal sinus ontogeny and SCSFR pathophysiology needs further studies.

Delayed Vision Loss Post Assault-Induced Zygomatic Fracture Repair in a Patient with an Ipsilateral Anterior Clinoid Process Pneumatization, A Case Report

A 27-year-old male presented one week after surgical repair of his fractured left zygomatic arch, 5 weeks post-assault, complaining of persistent blurred vision in the left eye and worsening migraine headaches. Magnetic resonance images (MRI) revealed no intra-orbital pathologies or optic neuropathy but demonstrated a clearly delineated air-filled space of the left anterior clinoid process (ACP). No vision threatening pathologies were identified and surgical treatment was not recommended. His blurred vision remained at 6-month follow up. We report a case of delayed vision loss and headache post zygomatic fracture repair surgery in patient with a confirmed ipsilateral ACP pneumatization.

Anatomical Variations of the Sphenoid Sinus and its Adjacent Critical Structures Using Cone Beam Computed Tomography: A Cross-Sectional Study

Background: The aim of the study was to determine the anatomical variations of the sphenoid sinus and its adjacent critical structures using Cone-Beam Computed Tomography (CBCT).&#x0D; Methods: This cross-sectional study was conducted on CBCT scans of 67 females and 84 males between 18 to 67 years. Presence/ absence of intersphenoid septa, sphenoid sinus pneumatization and its type (conchal, presellar, sellar, and postsellar a and b), protrusion of the optic canal and carotid canal into the sphenoid sinus, optic canal and carotid canal dehiscence, and Anterior Clinoid Process (ACP) pneumatization was evaluated on CBCT scans, and their prevalence and correlation were calculated. Data were analyzed by the Chi-square test (alpha=0.05).&#x0D; Results:The prevalence of intersphenoid septa was 98.68%. Postsellar type a was the most common type of sphenoid sinus pneumatization with a prevalence of 41.3%. The prevalence of conchal, presellar, sellar and postsellar b types was 0, 11, 30, and 17.7%, respectively. The prevalence of optic canal and carotid canal protrusion into the sphenoid sinus was 50 and 52.7%, respectively. The prevalence of optic canal and carotid canal dehiscence was 48.3 and 40.3%, respectively. The prevalence of ACP pneumatization was 45%. Optic canal and carotid canal protrusion had a significant correlation with ACP pneumatization (p&lt;0.001). Also, carotid canal and optic canal protrusion and dehiscence were significantly correlated with degree of sphenoid sinus pneumatization (p&lt;0.001).&#x0D; Conclusion: Sphenoid sinus pneumatization significantly increases the likelihood of carotid canal, optic canal protrusion into the sphenoid sinus and their dehiscence, therefore, a preoperative 3D imaging is strongly recommended prior to trans-sphenoidal surgical procedures.

Racial, Ethnic, and Gender Variations in Sinonasal Anatomy.

Complications during endoscopic sinus surgery often result from unfavorable anatomy. The prevalence rates of such anatomic findings vary tremendously in the literature, in part due to the small, homogenous populations previously studied. To characterize the prevalence of sinonasal anatomic variants among ethnic groups and genders seen at an academic medical center. This is a retrospective cross-sectional study of adult subjects who underwent CT imaging of the sinuses from January 2019 to November 2020 at a tertiary academic setting. CT scans were analyzed systematically by 3 trained study personnel for the presence of critical sinus anatomic variants that endoscopic sinus surgeons typically evaluate for preoperatively. Chi-squared tests and analyses of variance were conducted to detect differences in the prevalence of structural findings between genders and races/ethnicities. A total of 489 subjects (57% female) were included: 44 Asian, 14 Black/African American, 101 Hispanic/Latino, 203 White, 127 Other. The prevalence of the following anatomical variants differed by race/ethnicity: Haller cells, Type 3 optic nerve, Onodi cells, maxillary septations, sphenoid lateral recess, anterior clinoid process pneumatization, and carotid artery dehiscence. Asian subjects had higher rates of Haller cells (48% vs 16%, P < .001) and Type 3 optic nerve (18% vs 4%, P = .022) compared to Hispanic subjects, as well as a higher prevalence of Onodi cells (39% vs 17%, P = .003) compared to White subjects. Males had a higher prevalence of mesenteric anterior ethmoid arteries (62% vs 45%, P < .001) and dehiscent carotid arteries (30% vs 21%, P = .024). Certain sinonasal anatomic variants, which have direct implications for complications during endoscopic sinus surgery, were found to be significantly more prevalent in some demographic groups. Surgeons should be aware of these differences in their review of preoperative imaging for safe surgical planning.

Change in the Location of the Optic Strut Relative to the Anterior Clinoid Process Pneumatization.

This study aimed to peruse the alteration of the position of the optic strut (OS) according to the anterior clinoid process (ACP) pneumatization. This retrospective study conducted on cone-beam computed tomography images of 400 patients with a mean age of 36.49±15.91 years. Anterior clinoid process length, width, and angle were measured as 10.56±2.42mm, 5.46±1.31mm, and 42.56±14.68 degrees, respectively. The tip of ACP was measured as 6.60±1.50mm away from the posterior rim of OS. In the 631 sides (78.87%) did not have ACP pneumatization. In the cases with ACP pneumatization, three different configurations were identified as follows: Type 1 in 71 sides (8.87%), Type 2 in 56 sides (7%), and Type 3 in 42 sides (5.23%). Relative to ACP, the location of OS was determined as follows: Type A in 29 sides (3.64%), Type B in 105 sides (13.12%), Type C in 344 sides (43%), Type D in 289 sides (36.12%), and Type E in 33 sides (4.12%). The spread of data related to the attachment site of OS according to the presence or absence of ACP pneumatization showed that the location of OS was affected by ACP pneumatization ( P <0.001). In ACPs with pneumatization, the frequency of OS position relative to ACP was found as follows: Type A in none of sides (0%), Type B in 8 sides (7.6%), Type C in 53 sides (15.4%), Type D in 88 sides (30.4%), and Type E in 20 sides (60.6%). The main finding of this study was that the location of OS relative to ACP was affected by ACP pneumatization. In ACPs with pneumatization, OS was located more posteriorly compared with ACPs without pneumatization.

A Study of Anatomical Variations of Sphenoid Sinus on CT PNS: Our Experience.

Sphenoid sinus anatomical variations are very common, its prior knowledge is very essential while doing skull base surgery to avoid catastrophic complications which might be due to damage of surrounding neurovascular structures. This retrospective observational study was done to examine the different anatomical variations of sphenoid sinus on CT PNS which was conducted in KMCH, Katihar from May 2019 to April 2020 involving 60 cases above 15years of age who had undergone CT PNS. Sellar type of pneumatization was seen in 66.7%, pterygoid process pneumatization was seen in 25%. Single septation was present in 43.3%, septum attached to optic nerve was seen in 33.3%, onodi cell was seen in 36.7%, anterior clinoid process pneumatization was seen in 13.3% of cases. By this study we came to a conclusion that preoperative assessment of sphenoid sinus anatomy and its variations is mandatory to avoid surrounding neurovascular structure damage and CSF leak.

Evaluating the frequency of anatomical variations of the sinonasal region in pediatric and adult age groups according to gender: computed tomography findings of 1532 cases

BackgroundThe aim of the present study was to evaluate retrospectively the frequency of anatomical variations in sinonasal region, which were frequently seen in our cases, for whom coronal section paranasal computed tomography imaging (CPNCT) was taken, as well as the correlation of these variations with age and gender and correlations of identified anatomical variations with one another.In the study, CBCT scans of a total of 1532 (825 males and 707 females) cases were evaluated in order to determine the prevalence of anatomical variations of the nasal cavity and paranasal sinuses. All the images were taken by a multi-detector CT device (Aquilion, Toshiba medical system, Tokyo, Japan).ResultsMost frequently detected three anatomical variations were septum deviation (79.7%), concha bullosa (40.9%), and ethmoid bulla (21.0%) according to the frequency order. When the frequency of anatomical variations was evaluated according to gender, septum deviation, concha bullosa, and anterior clinoid process pneumatization were more frequently observed in males and Onodi cell in females (p < 0.05).When the relationships of the anatomical variations with one another were evaluated, it was found that the possibility of the presence of concha bullosa in the septum deviation cases and the presence of ethmoid bulla in the cases with Haller cell septum were higher (p < 0.05).In terms of the anatomical variations that were evaluated by taking age as the independent variable, a statistically significant difference was observed in pterygoid process pneumatization, Haller cell, pneumatized crista galli, ethmoid bulla, and paradoxical middle concha between the adult and children age groups (p < 0.05).ConclusionIn terms of the frequency of occurrence to various sinonasal region variations, statistically significant differences were observed between both genders and age groups. The correlations of the detected variations with each other were also remarkable. Consequently, it is believed that comprehensive studies and serious objective evaluations evaluating the change of frequency of anatomical variations according to age and gender besides their correlation with each other are required.

Analysis of correlation between the pneumatization degree of paranasal sinuses and skull base and spontaneous cerebrospinal fluid rhinorrhea

Objective:To investigate the relationship between the pneumatization degree of paranasal sinuses and skull base and the incidence of spontaneous cerebrospinal fluid rhinorrhea （SCSFR）. Methods:Date of 107 patients with SCSFR were reviewed retrospectively. Using CT scans, investigator evaluated the pneumatization degree of paranasal sinuses and skull base, and compared classifications of various imaging characteristics between SCSFR group（case group） and nasal septum deviation group（control group）, including frontal cells, Onodi cell, lateral recess of sphenoid sinus （LRSS）, pneumatization of anterior clinoid process and pneumatization of posterior clinoid process. Results:One hundred and eight fistulas are found among 107 cases. The most common site of the fistulas is found in ethmoid sinus （38.89%）, followed by olfactory cleft（37.04%）, sphenoid sinus （21.30%） and frontal sinus （2.77%）.The incidence of Onodi cell was significantly different between case and control group（χ²=4.755, P<0.05）, and the classification of Onodi cell has a linear effect on the occurrence of SCSFR （Z=3.345, P<0.05）, which suggests the increasing level of Onodi cell can increase the probability in occurrence of SCSFR. The incidence of type Ⅲ LRSS in the case group is significantly higher than in the control group（χ²=18.725, P<0.05）,a linear correlation is found between the classification of LRSS and the incidence of SCSFR （Z=3.578, P<0.05）.There was no significant difference in the incidence of frontal cells between the two groups（χ²=0.672, P>0.05）, nor was there a linear relationship between the classification of frontal cells and the incidence of SCSFR （Z=0.503, P>0.05）. Pneumatization of anterior clinoid process and posterior clinoid process were no significant difference between case and control （P>0.05）,nor were there linear relationships between their classifications and SCSFR （P>0.05）. Conclusion:The most common site of SCSFR is ethmoid sinus, followed by olfactory cleft,the hyperpneumatization of the LRSS and Onodi cell are closely related to its pathogenesis.

The pneumatization of the sphenoid sinus, its variations and relations with surrounding neurovascular anatomic structures: A computerized tomography study

Introduction and objectivesThe wide range of variability of SS pneumatization and relation with surrounding structures can result in serious complications; seeing that, the assessment of regional anatomy is essential for both surgeons and radiologists. We mainly aim to reveal the possible correlation between the SS pneumatization types and protrusion/dehiscence of the adjacent neurovascular structures in a larger population by using computerized tomography (CT) images. MethodsThe type of SS pneumatization (I–IV), pneumatization of anterior clinoid process (ACP), greater wing of sphenoid (GWS), and pterygoid process (PP) was evaluated. Protrusion and dehiscence of ICA, ON, MN, and VN was noted. Results1003 patients were included into the study. ICA, ON, and MN protrusions were not seen in patients with the type I or II SS on both sides. These protrusions were most frequently seen along with the type IV SS on both sides (p < 0.05). ICA, ON, MN, and VN dehiscence was not found in any patients with the type I SS. The rate of ICA protrusion increased with presence of GWS and PP; ICA dehiscence was found to be positively correlated with ACP, GWS, and PP pneumatization. ConclusionsVariations, either amount or the extent, of the pneumatization of the SS are related with the presence of protrusion/dehiscence of ICA, ON, MN and VN. Knowing and reporting these relations can decrease the rate of complications during skull base surgery.

STUDY ON THE OPTIC NERVE VARIATIONS IN RELATION TO POSTERIOR PARANASAL SINUSES USING CT IN TERTIARY CARE CENTRE

Background and objectives: Optic nerve has a close relationship with the posterior paranasal sinuses. Depending on the degrees of pneumatization of these sinuses, the optic nerve may indent the sinus wall or protrude into them, predisposing the nerve to injury during sinus surgeries. Aim was to analyse the optic nerve variations in relation to the posterior paranasal sinuses and to categorize the subjects as per DeLano's classification.&#x0D; Methods: Cross-sectional study was conducted on 336 patients above 16 years of age who underwent computed tomographic evaluation of head and brain. From volume data, multiplanar reconstructions were made in axial, coronal and sagittal planes and analysed in both bone and soft-tissue windows. Relationship of optic nerve with posterior paranasal sinuses were categorised into 4 types according to DeLano's classification. Bony dehiscence of optic canal and pneumatization of anterior clinoid process were also assessed.&#x0D; Results: 672 optic nerves were assessed, the most common optic nerve type identified was type 1 (62.6%), followed by type 2 (18.6%). Types 3 and 4 were seen equally in number (9.6% each). Dehiscence of optic nerve canal and pneumatization of anterior clinoid process (ACP) was seen respectively on 66 (9.8%) and 75 (11.2%) sides. Compared to type 1 and 4 optic nerves, dehiscence of bony optic canal was statistically more significant in type 2 and 3 nerves. 45.5% individuals with anterior clinoid process pneumatization had associated optic canal dehiscence, which was found to be statistically significant.&#x0D; Conclusion: Optic nerve variations were identified and classified according to DeLano’s classification. The range was within international limits and type 1 was the most common occurrence. When compared to other similar studies among Indian population, disparity observed in the frequency of optic nerve types and bony optic canal dehiscence in our study, were probably due to differences in ethnicity and size of study group. Association of bony optic canal dehiscence with type 2 &amp; 3 optic nerves and ACP pneumatization with type 3 optic nerve was found to be statistically significant, making them more vulnerable to injury during surgery. Knowledge of optic nerve relation with posterior paranasal sinuses, and its identification in preoperative computed tomography (CT) scan are important to avoid injury to optic nerve.&#x0D; Keywords: Optic nerve, sphenoid sinus, posterior ethmoid cell, Onodi cell, anterior clinoid process pneumatization, optic canal dehiscence.

Normal Variations in Sphenoid and Their Significance Regarding Endoscopic Sinus Surgeries: Multislice Computed Tomographic Study

Background:Sphenoid sinus (SS) is one of the most variables of all sinuses and its relation to vital vascular and nervous elements as optic nerve (ON), cavernous sinus, pituitary gland, and internal carotid arteries. This makes its transsphenoidal approach a challenge for functional endoscopic sinus surgeries (FESS). We aimed to delineate SS radiologically using multislice computed tomography (MSCT), to show normal variations in pneumatization pattern, septation, intercarotid distance, bony covering of carotid artery and ON, to provide successful and safe FESS -transsphenoidal surgeries and to decrease morbidity and mortality during its surgeries. Methods and materials: A prospective observational study on 210 patients from May 2017 to July 2019 was conducted and included all cases requiring MCTS, with free sphenoid sinus. We excluded patients who have pathology in SS, or previous SS surgery. Results: Onodi cells presented in 67 of cases case (31.9%) from whom 30 cases (14.3%) were bilateral, and 143 cases were absent (68.1%). Pneumatization of SS, sellar (adult) type is the most common type of pneumatization that presented in 160 cases (76.2%), presellar (juvenile) type in 48 cases (22.9%), then conchal (fetal) type only in 2 cases (0.95%). The relation between pneumatization of anterior clinoid process (ACP) and dehiscence of ON showed that among 168 cases who had absent ACP pneumatization, 159 of them showed no ON dehiscence (94.6%). Pneumatization of greater wing of sphenoid was in 28 cases (41.8%). Type I ON presented in 321 cases (76.4%), type II was in 54 (12.8%), type III was in 21 (5%), and type IV was in 24 cases (5.7%). Inter sphenoid septum was found in 119 cases (56.7%), multiple septa were found in 87 (41.4%), and no septum in 4 cases (1.9%). Dehiscence in carotid artery occurred in 17% of cases. Conclusion: We concluded SS variations, septation pattern, type of pneumatization, and onodi cells. All that will help preoperative regarding transsphenoidal surgeries, as that decrease morbidity and mortality by avoiding injury of important structures.

Radiologic analysis of correlations between sinonasal anatomical variations in patients with nasal septal deviation

Objective: This study aims to analyze the sinonasal anatomical variations accompanying the nasal septal deviation, the correlations between these variations, and their relationship with the septal deviation angle.Methods: In this retrospective study, preoperative paranasal computed tomography (CT) scans of 206 patients who underwent septoplasty between January 2015 and December 2019 were examined. In CT scans, different nasal septal deviation types, Keros classification, optic nerve type, ethmoid air cell variants, nasal concha variants, paranasal sinus pneumatization variants, and the correlation between accessory pneumatization variants and their relationship with the septal deviation angle were analyzed.Results: In patients with nasal septal deviation, supraorbital ethmoid cell, anterior clinoid process pneumatization and onodi cell were more frequent compared to the literature. Any significant correlation between the nasal septal deviation angle and the presence of sinonasal variants was not detected (p &amp;gt; 0.05). Correlations were significant between the presence of Frontal sinus hypoplasia and Haller cell (ϕ = -0.142, p = 0.042), Supraorbital Ethmoid cell (ϕ = -0.173, p = 0.013) and Paradoxal middle concha (ϕ = 0.152, p = 0.029).Conclusion: Careful examination of paranasal CTs before craniomaxillofacial surgeries is important to determine sinonasal anatomic variants, to determine the appropriate treatment plan and to prevent possible complications peroperatively.

Reproducibility of a new classification of the anterior clinoid process of the sphenoid bone.

Background: Pneumatization of the anterior clinoid process (ACP) affects paraclinoid region surgery, this anatomical variation occurs in 6.6–27.7% of individuals, making its preoperative recognition essential given the need for correction based on the anatomy of the pneumatized process. This study was conducted to evaluate the reproducibility of an optic strut-based ACP pneumatization classification by presenting radiological examinations to a group of surgeons.Methods: Thirty cranial computer tomography (CT) scans performed from 2013 to 2014 were selected for analysis by neurosurgery residents and neurosurgeons. The evaluators received Google Forms with questionnaires on each scan, DICOM files to be manipulated in the Horos software for multiplanar reconstruction, and a collection of slides demonstrating the steps for classifying each type of ACP pneumatization. Interobserver agreement was calculated by the Fleiss kappa test.Results: Thirty CT scans were analyzed by 37 evaluators, of whom 20 were neurosurgery residents and 17 were neurosurgeons. The overall reproducibility of the ACP pneumatization classification showed a Fleiss kappa index of 0.49 (95% confidence interval: 0.49–0.50). The interobserver agreement indices for the residents and neurosurgeons were 0.52 (0.51–0.53) and 0.49 (0.48–0.50), respectively, and the difference was statistically significant (P < 0.00001).Conclusion: The optic strut-based classification of ACP pneumatization showed acceptable concordance. Minor differences were observed in the agreement between the residents and neurosurgeons. These differences could be explained by the residents’ presumably higher familiarity with multiplanar reconstruction software.

Relation between optic and carotid canals with sphenoid sinus in patients with communicant hydrocephalus: a computed tomography evaluation study.

There are neuro-ophthalmologic findings in patients with communicant hydrocephalus (CH). To investigate the relationships of the optic canal and carotid canal classifications at sphenoid sinus and anterior clinoid process (ACP) pneumatization in patients with CH. In this multicentric retrospective cross-sectional study, the cranial computed tomography (CT) images of 38 patients with CH (20 men, 18 women) and 40 controls (25 men, 15 women) were included. Optic and carotid canal classification at sphenoid sinus, ACP pneumatization, and sphenoid sinus septation were evaluated. In the CH group, type 3 optic canal was detected in 21.1% of the patients and type 4 optic canal was detected in 2.6% of the patients on the left side which was significantly different from the control group (P<0.05). In the CH group, type 3 carotid canal was detected in 21.1% of the patients (left) and 18.4% of the patients (right). ACP pneumatization was present in 13.2% of the patients in the CH group bilaterally. There were positive correlations between optic canal classifications and ACP pneumatization (P<0.05). There were also positive correlations between the right and left carotid canal classifications and ACP pneumatization (P<0.05). To avoid complications, CT should be evaluated carefully in patients with CH before surgical interventions in sphenoid sinuses and surgeons should work carefully in the sphenoid sinus or adjacent structures. The protrusion possibility of the optic canal or carotid canal to the sphenoid sinus may be higher in pneumatized ACP patients.

Anatomical Variations of the Nose and Paranasal Sinuses: A Computed Tomographic Study.

Retrospective study. Tertiary care center in the southern part of India. Radiological images of paranasal sinuses belonging to chronic rhinosinusitis patients managed between June 2016 and November 2018. The studied characteristics in the CT images included the deviated nasal septum (DNS), concha bullosa (CB), Haller cell (HC), Onodi cell (OC), pneumatization of anterior clinoid process (ACP), pterygoid base (PB), superior turbinate, inferior turbinate, crista galli (CG), and nasal septum. The height of the lateral lamella of the cribriform plate, the sphenoid pneumatization pattern, and the optic nerve relationship with sphenoid sinus were studied separately. The associations between these factors, and with maxillary sinus opacifications were also investigated. A total of 151 adult patients' CT images were analyzed. The most common manifestations noted were DNS, CB and pneumatized PB, seen in 83.4%, 49% and 47% of the patients respectively. The rates of HC, OC, pneumatized septum, pneumatized CG, and pneumatized ACP were 39%, 23%, 27%, 43% and 27% in that order. Rates of most of these variations were within the range reported in the literature. Chi square test revealed that the OC was independently associated with pneumatized CG and pneumatized septum. The maxillary sinus opacification was related to DNS and CB, but not with protrusion of tooth root into the sinus. Most of the anatomical variations were comparable with the reports across the globe, however, the associations between these variationsweren't commonin our cohort.