Assessment of variations in sphenoid sinus pneumatization in Indian population: A multidetector computed tomography study

Evaluation of Sphenoid Sinus Variations in Cleft Lip and Palate Patients: A Comprehensive Cone Beam Computed Tomography Analysis

OBJECTIVE

This study aims to compare sphenoid sinus variations between unilateral and bilateral cleft lip and palate (CLP) patients and healthy controls using CBCT images. It is notable for its large sample size and comparison of unilateral and bilateral cleft patients, cleft and noncleft sides, and different age groups.

DESIGN

Retrospective cohort study.

SETTING

University Hospital.

PATIENTS

CBCT images of 97 CLP patients (76 unilateral, 21 bilateral) and 97 healthy controls were evaluated.Main Outcome Measures: Sphenoid sinus main types, sellar subtypes, clival, and lateral extensions were assessed for all groups.

RESULTS

A significant increase in the anterior type was observed in both unilateral and bilateral CLP groups. The bilateral CLP group had a higher prevalence of the lesser wing type. In CLP and control groups, lesser wing, combined type, and lateral type were statistically significantly lower under 13 years of age.

CONCLUSIONS

The study highlights an elevated prevalence of anterior pneumatization in unilateral and bilateral CLP individuals, emphasizing its significance in surgery planning due to proximity to critical structures like the optic nerve and sphenopalatine artery. The increased prevalence of the lesser wing type in bilateral CLP patients requires extra caution during anterior clinoidectomy. Lower pneumatization rates in CLP patients under 13 suggest their sphenoid sinus development is similar to that of healthy individuals. Understanding these variations is crucial for appropriate surgical planning and avoiding complications during transsphenoidal surgery.

Surgical Navigation in the Anterior Skull Base Using 3-Dimensional Endoscopy and Surface Reconstruction

Importance

Image guidance is an important adjunct for endoscopic sinus and skull base surgery. However, current systems require bulky external tracking equipment, and their use can interrupt efficient surgical workflow.

Objective

To evaluate a trackerless surgical navigation system using 3-dimensional (3D) endoscopy and simultaneous localization and mapping (SLAM) algorithms in the anterior skull base.

Design, Setting, and Participants

This interventional deceased donor cohort study and retrospective clinical case study was conducted at a tertiary academic medical center with human deceased donor specimens and a patient with anterior skull base pathology.

Exposures

Participants underwent endoscopic endonasal transsphenoidal dissection and surface model reconstruction from stereoscopic video with registration to volumetric models segmented from computed tomography (CT) and magnetic resonance imaging.

Main Outcomes and Measures

To assess the fidelity of surface model reconstruction and accuracy of surgical navigation and surface-CT model coregistration, 3 metrics were calculated: reconstruction error, registration error, and localization error.

Results

In deceased donor models (n = 9), high-fidelity surface models of the posterior wall of the sphenoid sinus were reconstructed from stereoscopic video and coregistered to corresponding volumetric CT models. The mean (SD; range) reconstruction, registration, and localization errors were 0.60 (0.24; 0.36-0.93), 1.11 (0.49; 0.71-1.56) and 1.01 (0.17; 0.78-1.25) mm, respectively. In a clinical case study of a patient who underwent a 3D endoscopic endonasal transsphenoidal resection of a tubercular meningioma, a high-fidelity surface model of the posterior wall of the sphenoid was reconstructed from intraoperative stereoscopic video and coregistered to a volumetric preoperative fused CT magnetic resonance imaging model with a root-mean-square error of 1.38 mm.

Conclusions and Relevance

The results of this study suggest that SLAM algorithm-based endoscopic endonasal surgery navigation is a novel, accurate, and trackerless approach to surgical navigation that uses 3D endoscopy and SLAM-based algorithms in lieu of conventional optical or electromagnetic tracking. While multiple challenges remain before clinical readiness, a SLAM algorithm-based endoscopic endonasal surgery navigation system has the potential to improve surgical efficiency, economy of motion, and safety.

Anatomical variation in the sphenoidal sinuses in patients with chronic rhinosinusitis: A CT scan study

Computerized tomography (CT) of the skull base region has become an indispensable tool for endoscopic sinonasal surgery.

Objectives

Fundamental knowledge of the sinus anatomy is crucial for preoperative surgical planning. The aim of this research was to evaluate associations between the anatomical variations sphenoidal sinuses and chronic rhinosinusitis (CRS) by using CT.

Methods

A descriptive study was performed on patients with CRS, who were referred to the department of radiodiagnosis and imaging for CT scanning. Parameters were compared between the study and control groups.

Results

Among the anatomical variations, the presence of bilateral accessory septa within the sphenoidal sinus, and dehiscence and protrusion of the internal carotid artery and optic nerve (ON), were high in men and women in the case group compared with the control group. Among the anatomical variations in the sinonasal region of the male participants, a significant association (p < 0.05) was observed with ON protrusion and ON dehiscence. ON protrusion (OR = 2.168) in men was associated with elevated risk of CRS in the study population.

Conclusion

Knowledge of the anatomical variations in the sphenoid sinuses enables better understanding of the limits of surgical dissection during the treatment of sphenoid sinus surgeries.

Computed tomography-based assessment of sphenoid sinus and sella turcica pneumatization analysis: a retrospective study

Background

A preoperative three-dimensional examination of the sphenoid sinus anatomy, its pneumatization pattern, and its relevance to neighboring neurovascular constructions is crucial to preventing possible complications. In this study, the aim was to evaluate the relationship between sphenoid sinus pneumatization types and the sella turcica using computed tomography (CT).

Methods

CT data from 420 patients referred to the Department of Dentomaxillofacial Radiology were evaluated retrospectively. Sella pneumatization types were classified as conchal, presellar, incomplete sellar, and complete sellar, and they were evaluated. Obtained data were evaluated using the IBM SPSS 25.0 (Armonk, New York, USA) package program.

Results

CT images of 420 individuals, including 174 women and 246 men with a mean age of 43.87 ± 17.58 years, were included in the study. When the sella turcica morphologies were evaluated, the most widespread morphological type was irregularity in the posterior part of the dorsum sella, in 51.2% of cases. In addition, a statistically significant correlation was found between the pneumatization of the sphenoid sinus and the morphological types of sella (p < 0.05).

Conclusion

In this research endeavor, the predominant observation comprised the complete sellar sphenoid sinus pneumatization type, exhibiting irregularity in the posterior aspect of the dorsum sella, representing one of the sellar types. Notwithstanding, it is imperative to conduct additional investigations to establish the generalizability of the present study's findings.

Extended sphenoidotomy combined with transpterygoid approach for sphenoidal sinus inverted papilloma

PURPOSE

Inverted papilloma of the sphenoid sinus (IPSS) is a rare tumor with debated surgical management due to its proximity to vital structures. The aim of this manuscript is to highlight the role of a transpterygoid approach (TPA) and pedicle-orientated strategy in case of involvement of critical structures in IPSS and compare it with data from the literature.

METHODS

Patients with primary IPSS between January 2000 and June 2021 were included. Pre-operative CT/MRI were analyzed to classify the pneumatization of the SS and predict the insertion point of the inverted papilloma. All patients were treated with a trans-sphenoidal approach which was combined with a TPA in case of lateral insertion point. A systematic search was also performed to summarize the available literature.

RESULTS

Twenty-two patients were treated for IPSS. By CT, the SS was categorized with type III pneumatization in 72.8% of cases. Eleven patients (50%) were treated with a TPA with a statistical association with the insertion point on the SS lateral wall (p = 0.01), rather than a SS pneumatization (p = 0.63). The overall success was 95.5% after a mean follow-up of 35.9 months. For the literature, 26 publications were included on 97 patients and described a trans-sphenoidal approach with a success rate of 84.6% after a mean follow-up of 24.5 months.

CONCLUSION

IPSS is generally treated with a sphenoidotomy approach, although in selected cases, a TPA should be preferred to expose the whole SS lateral wall though allowing a complete pedicled oriented resection of the tumor.

Combined Radiological and Endoscopic Evaluation of Sino Nasal Anatomical Variations in Patients of Chronic Rhinosinusitis: A North Indian Study

To determine the prevalence of anatomical variations of nasal cavity and paranasal sinuses of patients with chronic rhinosinusitis (CRS) on CT scan imaging. To correlate the Anatomical variations with the extent of CRS. 100 patients attending the ENT outpatient department with clinically diagnosed CRS were selected for study based on inclusion and exclusion criteria. Patients were subjected to CT scan and diagnostic nasal endoscopy. The correlation of anatomical variation with severity of CRS based on radiological score and endoscopic score was observed. Deviated nasal septum was the most common anatomical variation observed in 71% cases. Followed by Agger nasi (68%), concha bullosa (55%), Onodi cell (25%), Haller cell (14%), frontal sinus hypoplasia (2%) and uncinate bulla (1%) respectively. Statistically significant relationship of radiological score with left side Bullous Concha Bullosa and highly statistically significant relationship with Haller Cell was observed. While statistically significant relationship between Deviated Nasal Septum on left side with endoscopic score was also observed. Correlation of anatomical variation with CRS concludes on the note that some variations cause impaired sinus drainage and ventilation leading to recurrent sinusitis. Also, incidence of these variations was comparable to other studies done in asymptomatic population therefore, simply detection of a solitary anatomical variant itself does not determine predisposition to disease or the pathogenesis of the CRS and that we should have a critical look out for these anatomical variations from point of view of surgical management.

Management of a pediatric patient with spontaneous cerebrospinal fluid leak in the lateral recess of sphenoid sinus and meningoencephalocele: A case report and literature review

INTRODUCTION AND IMPORTANCE

Spontaneous cerebrospinal fluid (CSF) leak in the lateral recess of the sphenoid (LRS) sinus in a pediatric population is rare and is surgically challenging to repair.

CASE PRESENTATION

We report a case of a 13-year-old girl with hydrocephalus and a ventriculoperitoneal shunt who presented with a two-month history of clear rhinorrhea from the right nostril. Computed tomography (CT) of the head was performed and showed CSF leak through a defect in the lateral recess of the sphenoid sinus. Defect closure was achieved using an endoscopic endonasal approach.

CLINICAL DISCUSSION

CSF leak with meningoencephalocele from the sphenoid sinus is amongst the most difficult cases for repair. Yet the successful rate of repair is as high as 90 % if done endoscopically. Moreover, the location of the defect determines the surgical approach.

CONCLUSION

Spontaneous CSF rhinorrhea from the lateral recess of the sphenoid (LRS) sinus, although rare, requires prompt diagnosis and treatment, as it may lead to significant mortality and morbidity.

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.

Pneumatization of the Greater Wing of Sphenoid Utilization for Lateral Wall Decompression

The goal of orbital decompression for thyroid orbitopathy is to expand the orbital space for the contents with various techniques described. Deep lateral wall decompression is a procedure that expands the orbit by removing bone from the greater wing of sphenoid however its effectiveness is dependent on the volume of bone removed. Pneumatization of the greater wing of sphenoid is defined as an extension of the sinus beyond the VR line (a straight line crossing the medial edges of the vidian canal and the foramen rotundum) which is a demarcation between the sphenoid body and the lateral parts of the sphenoid bone, including the greater wings and pterygoid process. We present a case of complete pneumatization of the greater wing of sphenoid affording a greater volume of bony decompression in a patient with significant proptosis and globe subluxation as a result of thyroid eye disease.

Sex Determination Using Human Sphenoid Sinus in a Northeast Iranian Population: A Discriminant Function Analysis

Statement of the Problem

Sex determination, using skeletal remains, is of paramount importance in forensic studies. The skull accounts for the most sexual dimorphism after the pelvis. Recent studies have shown that paranasal sinuses are valuable in sex determination and considering the location of the sphenoid sinus, the risk of traumatic injuries to this structure is low.

Purpose

The present study aimed to evaluate the morphology of the sphenoid sinus and determine the validity of sphenoid sinus volume (SSV) in sex determination using cone beam computed tomography (CBCT) images.

Materials and Method

In this cross-sectional retrospective study, CBCT images of 469 Iranian patients (186 male and 283 female), aged 24-45 years, were selected. The morphology of the sphenoid sinus was recorded. 3D Slicer software (4.10.0) was used to assess SSVs in coronal and axial planes. For data analysis, t-test, chi-square test, and discriminant function analysis (DFA) were performed using predictive analytics software (ver. 18.0).

Results

The most common morphology of the sphenoid sinus in both genders was the sellar type (50.5%). SSV was significantly larger in males than in females (p< 0.001). DFA showed that the capability of SSV in sex identification was 86.0% and 92.9% in males and females, respectively.

Conclusion

The findings of this study suggest that SSV is a reliable variable in gender discrimination in a northeast Iranian population. However, since the morphology of the sphenoid sinus and sex were independent of each other, the morphology of the sphenoid sinus is not a suitable indicator for sex determination.

Relationship of sphenoid sinus to adjacent structures in South India: a retrospective cross sectional study

Background

Sphenoid sinus is one of the most inaccessible paranasal sinuses. Advent of minimally invasive trans-nasal trans-sphenoidal approach over the past few years has provided an additional armament in the hands of skull-base surgeons to access pathologies adjoining base of skull. Close relationship of vital neurovascular structures with sphenoid sinus and variability of their protrusions into the sinus make these structures more vulnerable to iatrogenic trauma during surgical procedures. Preoperative assessment of such variations is imperative to avoid unintentional damage. The present study is a retrospective study conducted on CT scan records of 140 patients with an aim to evaluate prevalence of vital structures invaginating into sphenoid sinus and their clinical implications. The internal carotid artery (ICA), optic nerve (ON), maxillary nerve (MN), and Vidian nerve (VN) were assessed for protrusion into the sphenoid sinus and their dehiscence. Attachment of septum to protruding structures was also assessed. Data was statistically analyzed in the form of frequency and percentage to evaluate the prevalence of neurovascular invaginations into sphenoid sinus and their clinical implications.

Results

ICA invagination was observed in 16% of males and 12% of females with males showing higher frequency on left side. Protrusion of ON was seen in 13% of males and 10% of females with higher prevalence in bilateral category. Twenty-four percent of study population had MN prominences which included 13% of males and 11% of females with higher reflection of bilateral presentation. Highest prevalence of 44% was observed in VN protrusions with equal distribution (22%) among each sex. Majority of these were bilaterally located. Dehiscence of ICA was observed in 9%, ON in 29%, MN in 10%, and VN in 30% of study population. Dehiscence brings these structures closure to sinus mucosa with increased risk of involvement in sinus disease. Septal attachment to ICA and ON was present in 7% and 15% cases respectively.

Conclusion

Preoperative assessment of anatomical configuration of sphenoid sinus and associated neurovascular structures is mandatory to minimize per-operative complications. This study provides statistical data on anatomical variations in neurovascular structures protruding into the sphenoid sinus, their dehiscence, and septal attachments in South Indian population.

Racial, Ethnic, and Gender Variations in Sinonasal Anatomy

BACKGROUND

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.

OBJECTIVE

To characterize the prevalence of sinonasal anatomic variants among ethnic groups and genders seen at an academic medical center.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

Anatomical Variations of Sphenoid Sinus in South Indian Population: All That You Need for Trans-Sphenoidal Pituitary Surgery

Pituitary adenomas are one among the most common neurosurgical tumors with an incidence of 10-25% among intracranial neoplasms (Ezzat et al., Cancer 101:613-619, 2004). Surgical management for the same has been practiced since long, and has evolved from trans cranial approach to endoscopic trans sphenoidal method (Hammer and Radberg, Acta Radiol 56:401-422, 1961). Preoperative radiological analysis with CT &MRI is inevitable in planning endonasal trans-sphenoid surgery to avoid complications because of the high variability concerned with sphenoid anatomy. The present study intends to analyze the incidence of various anatomical variations of sphenoid sinus in a cohort of south Indian population as detected by CT& MRI and assess its impact on surgical approach. Retrospective analysis of CT&MRI images of patients who underwent Endonasal Trans-sphenoidal resection of pituitary tumors at JSS Hospital Mysuru from a period of 2009 to 2020 is done. Anatomical variations of sphenoid sinus esp. degree of pneumatization, sellar configuration, septation pattern, inter carotid distance were evaluated. Results were significant and in concordance with other similar studies. Most frequently encountered pnuematization was sellar type and least was conchal type Sphenoid sinus pneumatization is directly linked to safe access to sella. Presence of septae within sinus need to be identified preoperatively to avoid damage and confusion intraoperatively. A meticulous preoperative analysis of sphenoid sinus anatomy will help surgeon in smooth conduct of a complication free surgery.

Cone beam computed tomography evaluation of sphenoid sinus in different sagittal skeletal pattern

Purpose

The purpose of this study is to explore sphenoid sinus variations in individuals with various sagittal skeletal anomalies using cone-beam computed tomography (CBCT).

Materials and methods

We retrospectively analyzed sphenoid sinus pneumatization on CBCT images of 126 patients aged 18-86 years. The anteroposterior skeletal relationships of the maxilla and mandible were classified as skeletal class I, II or III using the A point-nasion-B point (ANB) angle measured in the sagittal plane. The extensions of the sphenoid sinus were evaluated on three planes including axial, sagittal and coronal sections.

Results

The study population consisted of 84 females (66.7%) and 42 males (33.3%), including 52 (41.3%) class I, 38 (30.1%) class II, and 36 (28.6%) class III cases. The conchal type of sphenoid sinus was not encountered. Presellar sinuses were detected in only 3 (5.8%) class I cases. Incomplete sinuses were detected in 16 (30.8%) class I, 7 (18.4%) class II, and 15 (41.7%) class III cases. Complete sinuses were detected in 33 (63.4%) class I, 31 (81.6%) class II, and 21 (58.3%) class III cases. Lateral extensions were found in 103 (40.9%) of the 252 sinus walls: 33 (31.7%) in class I, 45 (59.2%) in class II, and 25 (34.7%) in class III sinuses.

Conclusion

Regional sphenoid sinus anatomy can be carefully examined via CBCT. The sphenoid sinus pneumatization did not differ significantly in patients exhibiting different types of sagittal skeletal closure, with the exception of the lesser wing type.

Investigation of the prevalence and main features of skull-base anomalies and characteristics of the sphenoid sinus using cone-beam computed tomography

Objectives

This study aimed to define the prevalence and characteristics of skull base anomalies and the features of sphenoid sinus pneumatization (SSP).

Materials and Methods

Five hundred cone-beam computed tomography scans were evaluated retrospectively for the presence of fossa navicularis magna (FNM), canalis basilaris medianus (CBM), sphenoid emissary foramen (SEF), and/or Onodi cells (OC). Patterns of the SSP and sphenoid sinus mucosa dimensions (SSMD) were also recorded.

Results

The prevalence of FNM, CBM, SEF, and OC was 26.0%, 22.4%, 47.4%, and 18.4%, respectively. Two hundred sixty-two (52.4%) sellar-type SSP were defined, followed by post-sellar 191 (38.2%), pre-sellar 31 (6.2%), and conchal 16 (3.2%) types. The frequency of SSMD less than 1 mm, 1-3 mm, and greater than 3 mm was 40.6%, 38.4%, and 21.0%, respectively. An SEF was detected more frequently in females, while SSMD greater than 3 mm was more frequent in males. An FNM was more prevalent in the 18-29 and 30-39 age groups and SEF was significantly less frequent in patients over 60 years of age compared to other age groups. A sinus mucosa larger than 3 mm was more common in the younger than 18 year group. The frequency of post-sellar-type pneumatization was lower in patients younger than 18 years.

Conclusion

Skull-base anomalies are common and may be detected incidentally during imaging procedures. The sphenoid sinus, its variations, and pneumatization patterns should also be taken into consideration in imaging procedures performed for various purposes.

Pituitary MRI Standard and Advanced Sequences: Role in the Diagnosis and Characterization of Pituitary Adenomas

Pituitary adenomas (PAs) represent the most frequently found lesions in the sellar region; however, several other lesions may be encountered in this region, such as meningiomas, craniopharyngiomas, and aneurysms. High-quality imaging is fundamental for diagnosis, characterization, and guidance of treatment planning of PAs. Sellar magnetic resonance imaging (MRI) is considered the imaging modality of choice for the evaluation of lesions in the sella turcica. The sellar MRI standard protocol includes coronal and sagittal T1-weighted spin-echo sequencing with and without gadolinium-based contrast agent and coronal T2-weighted (T2w) fast-spin echo sequencing. A systematic MRI approach to the pituitary region generally provides information that includes the size and shape of the PA, the presence of cysts or hemorrhage within the tumor, its relationship with the optic pathways and surrounding structures, potential cavernous sinus invasion, sphenoid sinus pneumatization type, and differential diagnosis with other sellar lesions. The standard protocol is sufficient for the evaluation of most cases; however, some advanced techniques (susceptibility imaging, diffusion-weighted imaging, 3D T2w high-resolution sequences, magnetic resonance elastography, perfusion-weighted imaging) may render additional information, which may be important for some cases. In this "approach to the patient" manuscript, we will discuss the use of standard and advanced MRI sequences in the diagnosis and characterization of PAs, including MRI features associated with treatment response that may aid in presurgical evaluation and planning, and red flags that may point to an alternative diagnosis.

The Evaluation of Variations in Patterns of Sphenoid Sinus Pneumatization Using Computed Tomography in a South Indian Population

Background and objective

Knowledge about sphenoid sinus pneumatization is critical for skull base surgeries and functional endoscopic sinus surgery (FESS) in order to avoid serious complications like postoperative meningitis, sinusitis, cerebrospinal fluid (CSF) rhinorrhea, and intracranial hematoma. In this study, we aimed to assess the proportion of anatomical variants in sphenoid sinus pneumatization and to determine the common sphenoid pneumatization pattern in a South Indian population.

Methods

This retrospective study was conducted over a period of six months from July 2019 to December 2019 among 573 patients who underwent non-contrast CT (NCCT) or contrast-enhanced CT (CECT) of the brain, paranasal sinuses (PNS), orbit, and face.

Results

Most of the patients were in the age group of 20-39 years. The male-to-female ratio was 2.45:1. Among the posterior extensions, the most common variant was type D, followed by type C, type B, and type A. Among the clival extensions, the most common variant was Cliv-A, followed by Cliv-B, Cliv-C, and Cliv-D. The most common lateral wall pneumatization was bilateral lateral wall pneumatization followed by unilateral sinus wall pneumatization. Lat-A was the most common lateral wall pneumatization pattern followed by Lat-D, Lat-B, and Lat-C.

Conclusion

Our study intends to classify the sphenoid sinus pneumatization pattern and identify the most common variant among them, thereby guiding the skull base and FESS surgeons in choosing the correct mode of the operative procedure and also anticipating and avoiding complications of surgery.

Pneumatization Patterns of the Sphenoid Sinus in Adult Nigerians and Their Clinical Implications

BACKGROUND

The variant pneumatization patterns of the sphenoid sinus have significant surgical implications due to their associated inconsistent neurovascular relations. This study aimed at evaluating the pneumatization patterns of the sphenoid sinus in adult Nigerians.

METHODS

This was a retrospective study conducted at the Radiology Department of a Tertiary Hospital in Nigeria after obtaining institutional ethical approval. Brain Computed Tomography images of 336 patients (137 females, 199 males) aged ≥20 years were studied for the variant pneumatization patterns of the sphenoid sinus. Statistical Package for Social Sciences version 23 was used for data analysis. Chi-square test was used to assess for the association of the variants with gender and side. Pvalue was considered significant at <0.05.

RESULTS

The predominant pneumatization pattern in relation to the seller turcica was the sellar type (181;53.9%) followed by the presellar type (65;19.3%), post-sellar (62;18.5%), and lastly the conchal type (28;8.3%). The most prevalent clival recess was the subdorsal type (25;7.4%) followed by the dorsal (18;5.4%), combined (7;2.1%), and lastly occipital (3;0.9%). The frequency of pneumatized anterior clinoid process, greater wing of sphenoid and pterygoid process was 76;22.6%, 60;17.9% and 141;42% respectively and these showed significant side difference (P=0.001 each). None of the pneumatization patterns showed a significant gender difference. Sphenoid sinus agenesis was not observed.

CONCLUSION

The pneumatization patterns in our study varied from the findings in previous Nigerian studies and other populations. There is therefore the need for preoperative evaluation before endoscopic transsphenoidal surgical procedures.

Vidian Canal as a Transcranial Landmark: Anatomy, Technique, and Illustrative Cases

Objective The vidian nerve can be accessed in transcranial approaches in carefully selected patients to ensure its preservation and to serve as a landmark for sphenoid sinus entry. This report is to review a technique, evaluate it in laboratory settings, and present two illustrative cases.

Design The study involves cadaveric dissection and illustrative cases.

Setting The study conducted in a cadaveric dissection laboratory.

Participants The object of the study is one cadaveric head and two illustrative clinical cases.

Main Outcome Measures Two cases using this approach were illustrated, and a cadaver dissection was performed in a step-by-step fashion.

Results: The vidian canal can be accessed by drilling the anterolateral triangle. Two illustrated cases were presented; in one, the vidian nerve was used as part of a corridor to access the sphenoid sinus for tumor delivery, and in the other, the technique was used to find and preserve the vidian nerve during transcranial resection.

Conclusion Careful identification of the vidian canal in transcranial surgery is a beneficial technique in carefully selected cases which allows identification of the nerve both for its preservation in selected cases and to create the vidian–maxillary corridor for tumor resection. Knowing the anatomy and pneumatization variants is important in the surgical approach.

Volumetric and linear evaluation of the sphenoidal sinus of a Brazilian population, in cone beam computed tomography

The determination of sex from skeletal remains has been widely used in biological profile reconstruction since these are some of the last structures to perish after death. The sphenoid sinus is located deeply in the skull and is enveloped by diverse structures within the sphenoid body. It is, therefore, less predisposed to injuries and/or pathological changes. The aim of this study is to evaluate the possibility of determining sex in a Brazilian population by means of linear and volumetric measurements of the sphenoid sinus, in addition to identifying and quantifying the presence of extensions of this sinus in cone beam computed tomography (CBCT) scans. In total 268 CBCT scans were analysed, from patients aged between 22 and 70 years old, of which 145 were female, and 123 were male. The images, representative of a Brazilian population, were selected by a dental radiologist from a CBCT image bank. The volumetric measurements were made by means of the segmentation software ITK-SNAP 3.0® and the linear inferio-superior, latero-lateral and anteroposterior measurements, as well as the presence of extensions of the sphenoidal sinus, were made using the CS Imaging Software®. The results of this study suggested that when comparing men and women, there were no statistical differences in the linear measurements and extensions of the sphenoidal sinus, although the values were considerable in the extensions for the pterygoid processes and greater wings of the sphenoid bone, particularly in women. However, there was a statistically significant difference when the sphenoidal sinus volume was compared, as it was larger for men (11.364 mm³ ± 4.229 mm³) than for women (10.000 mm³ ± 3.615 mm³). In summary, the sphenoidal sinus volumetric measurements in CBCT exams are useful for determining the sex of unknown individuals.

Anatomographic Variants of Sphenoid Sinus in Ethiopian Population

Neurosurgeons often neglect the sphenoid sinus due to its deep location and difficulties in accessing during surgical interventions. Disease of the sphenoid sinus is difficult to diagnose since its presenting symptoms are difficult to recognize. Moreover, compared with other paranasal sinuses, the sphenoid sinus is considered the most variable air sinus in terms of its degree of pneumatization, number and position of inter-sinus septa, and its relationship with the surrounding anatomical structures. Anatomical variations of the sphenoid sinus are significant from a neurosurgical point of view. Understanding of these variations and its relationships with surrounding structures such as the internal carotid artery, optic nerve, and pituitary gland are clinically relevant to minimize injuries associated with surgical procedures that involve sphenoid sinus. We implemented principles of imaging using computed tomography to elucidate any anatomical variations of the sphenoid sinus in the Ethiopian population. We conducted a prospective study in 200 patients with ages 18-79, who underwent scans of the sphenoid sinus at the Tikur Anbessa Referral Teaching Hospital in 2017-2018. Our findings revealed an incidence of anatomographical variations in terms of pneumatization that varied between 2-50%. These variants include 2% conchal, 25.5% presellar, 50% sellar, and 22.5% postsellar pneumatization. We also demonstrated anatomographic variants in terms of septation, 77.5% single complete septa, 11.5% single incomplete, 10% double septa, and 1% absence of septa. In summary, the sellar pneumatization was found to be the most clinically relevant anatomographic variant among Ethiopians participating in the study, of which 90% were tomographically single septated. These variants must be taken into consideration during trans-sphenoidal surgery and knowledge of the variations has clinical implication in minimizing injuries during invasive surgical procedures involving the sphenoid sinus.

A new classification proposal for sphenoid sinus pneumatization: a retrospective radio-anatomic study

OBJECTIVES

The sphenoid sinus variations are very diverse and the frequency of these sinus variations is high. During operations involving the sphenoid sinus, such as pituitary surgeries, the surgeon should have detailed information about these variations. The aim of this study is to reclassify the sphenoid sinus pneumatizations in detail and to evaluate the incidence of pneumatization types in a Turkish population according to this classification.

METHODS

New classification proposal was made. In accordance with the proposed new classification, sphenoid sinus pneumatizations were evaluated on CBCT images.

RESULTS

When the posteroanterior pneumatization of 128 patients was evaluated; 2.3% conchal, 3.9% presellar, 35.9% sellar, and 57.8% postsellar pneumatization was detected. Of these cases, 28.9% had anterior pneumatization on the right and 23.4% on the left. When lateral direction pneumatizations were evaluated, lateral body type was found to be the most common on both right (44.1%) and left (42.5%) sides.

CONCLUSION

In this study, sphenoid sinus pneumatizations were evaluated three-dimensionally with the help of CBCT, and a new classification suggestion was made to eliminate the classification confusion we encountered in our previous studies. Pneumatizations and variations can affect the field of operation and even change planning. It should be taken into account that the paranasal sinuses may have variations due to their surgical importance and their close association with many vital structures.

Ten must know pseudolesions of the head and neck

Patients may present in the emergency setting for a variety of head and neck complaints such as fever, trouble swallowing, or a newly palpable mass. When reviewing radiologic head and neck exams for etiology of complaints, it is important to be familiar with the multiple pseudolesions that may mimic pathology. These may be normal variant anatomy, normal anatomy located in an atypical location, as well as iatrogenic or self-introduced foreign bodies. This review article discusses ten common pseudolesions encountered in the head and neck and their typical imaging appearance so that one does not mistake them for ominous pathology, thus preventing unnecessary follow-up, biopsy, or continued concern for the patient.

Sphenoid sinuses: pneumatisation and anatomical variants-what the radiologist needs to know and report to avoid intraoperative complications

PURPOSE

Sphenoid sinuses are pneumatised structures, placed in the body of the sphenoid bone, with highly variable morphology. The strict relationships with vascular and nervous structures determine the importance of their anatomical variants in otorhinolaryngology and neurosurgery; a precise understanding of the complex anatomy and anatomic variations of these structures is pivotal for radiological diagnosis of paranasal sinuses pathology and for surgical planning, to avoid potential complications. Our aim is to describe the anatomical variants of sphenoid sinuses, and to help general radiologists and specialists in endoscopic surgery in becoming familiar with these sensitive anatomical structures.

METHODS

A literature search of PubMed and Embase (Elsevier) databases was performed using the keywords "sphenoid sinus" and "anatomy, "sphenoid sinus" and "anatomic variants", "sphenoid sinus", and "anatomic variations".

RESULTS

We described the anatomical variants of the sphenoid sinuses anatomy, according to their size, shape, degree of pneumatisation, protrusion of anatomical structures into their lumen, superimposition of ethmoid cells (Onodi cells), and presence of accessory septations CONCLUSION: The information provided by this study may help in the identification and description of the anatomical variations of the sphenoid sinuses and their relationship to neurovascular structures.

Assessment of sphenoid sinus types in patients with cleft lip and palate on cone-beam CT

PURPOSE

The aim of this study is to examine the sphenoid sinus morphology and variations in patients with cleft lip and palate (CLP) on cone-beam computed tomography (CBCT) images, and to compare them with healthy controls.

METHODS

CBCT images of 54 patients (28 males and 26 females,) with CLP and 54 age- and gender-matched healthy individuals (28 males and 26 females) were retrospectively evaluated. Sphenoid sinus main types (conchal, presellar, sellar, postsellar), sellar subtypes, clival and lateral extensions, and sinus septation were analyzed in CLP and control groups. The data were statistically analyzed using Chi-square test to compare the groups.

RESULTS

A statistically significant difference was found between CLP and control groups for sphenoid sinus main types (p < 0.05). Presellar type was more commonly observed in CLP group (18.5%), while the postsellar (31.5%) and clival (17.7%) types were more frequent in control group. There was a significant difference between the groups among different sellar sinus subtypes (p < 0.05). A significant difference was detected between the groups for clival extensions of sphenoid sinus (p < 0.05), but no difference was found for the lateral extensions (p > 0.05). No significant difference was determined between groups for sphenoid sinus septation (p > 0.05).

CONCLUSION

Significant differences were found between the CLP and control groups in terms of sphenoid sinus main types, sellar subtypes and the clival extensions. Knowledge of sphenoid sinus pneumatization in patients with CLP is important for preventing complications during transsphenoidal surgery.

Vidian canal and sphenoid sinus: an MDCT and cadaveric study of useful landmarks in skull base surgery

PURPOSE

To present the anatomical variations of vidian canal (VC) and sphenoid sinus (SS), relative to other anatomical landmarks of skull base area, which may be helpful for safer surgical approach to this area.

MATERIALS

MDCT scans (128-row MDCT system) of 90 patients (mean age 62 years) and six cadaveric heads were studied, and the following parameters were evaluated: mean length and types of VC, distance between VC and foramen rotundum (FR) and optic canal (OC), position of the VC regarding the lateral pterygoid plate (MPTG) and petrous ICA, pneumatization of SS, position of intrasinus septum regarding ICA and OC, bone dehiscence and protrusion of ICA and OC into SS. Six cadaveric heads underwent MDCT and endoscopic dissection, and the type and length of VC were evaluated. The statistical significance was assessed using Chi-square (χ²) test. Significance level was set at p < 0.05.

RESULTS

A statistical analysis was performed between the measurements at both sides, as well as between measurements in MDCT and dissection of the six cadaveric heads. Statistically significant difference was found between right and left sides in the horizontal and vertical distances between FR and VC, as well as between VC and OC. Also, there was a statistically positive correlation between type II of VC and lateral pneumatization on the right side. There was not statistically significant difference concerning VC type and length between MDCT and dissection measurements.

CONCLUSION

Surgeons addressing skull base surgery must be familiar with the anatomical and positional variations of VC and SS in the preoperative CT images so as to avoid serious complications during surgery.

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

To evaluate the anatomical variations in computed tomographic (CT) images of paranasal sinuses and to investigate association between them.

DESIGN

Retrospective study.

SETTING

Tertiary care center in the southern part of India.

SUBJECTS

Radiological images of paranasal sinuses belonging to chronic rhinosinusitis patients managed between June 2016 and November 2018.

METHODS

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 variations weren't common in our cohort.

Contrasting Surgical Management of CSF Leak from Lateral Recess of Sphenoid Sinus and Its Surgical Outcomes: Our Experience

CSF leak from Lateral Recess of Sphenoid (LRS) sinus accounts for 35% of all CSF rhinorrhoea cases. There are various surgical techniques described for repair of LRS CSF leak. This study describes the experience of LRS leak repair in a tertiary care center with three different surgical techniques. Study comprises of 3 cases of LRS CSF leak that presented to J.S.S. Hospital, during the time period of July 2018-January 2019, who underwent endoscopic CSF leak repair. All three cases underwent endoscopic endonasal transpterygoid approach to the leak site. The closure technique opted for all three cases were different. For the first case free mucosal flap from ipsilateral middle turbinate was used, for the second ipsilateral nasoseptal flap (NSF) was used and contralateral NSF was used for the third. All the cases were followed up for a minimum of 3 months. In all the 3 cases the CSF leak site was located in the lateral recess of Sphenoid sinus. Encephalocele was noted in two cases, which were cauterised and closure was done as planned. Crusting was more in cases that underwent closure using free mucosal flap. Healing and take up was similar for both the ipsilateral NSF and contralateral NSF. The endoscope has revolutionized the management of CSF leak from the lateral recess of sphenoid sinus. These defects can be managed efficiently using multilayer closure of defect. For large defects, the Posterior nasoseptal flaps can be used. In addition, contralateral PNSF has lower chances of being devascularized due to injury to pedicle while drilling the pterygoid plates.