Intersinus Septal Cell Research Articles

Evaluation of the Association between Paranasal Sinus Osteomas and Anatomic Variations Using Computed Tomography

Objective:The pathogenesis of paranasal sinus osteoma (PSO) has not been fully elucidated. It is thought that both embryological and developmental factors play a role in the etiology. The aim of the present study was to investigate the association of frequency and localization of PSOs detected on computed tomography (CT) examination with osteoma presence.Methods:In this retrospective study conducted in December 2017 through March 2020 in Gaziosmanpaşa University Faculty of Medicine, images of a total of 18,867 patients who underwent paranasal sinus, maxillofacial CT and brain CT angiography were reviewed for the presence of PSOs. Sizes of PSOs and accompanying mucosal pathologies were identified. Associations between PSOs and paranasal sinus variations were evaluated statistically compared to the control group (200 patients without PSO).Results:A total of 176 patients (0.92%) were found to have PSO. Average age of the patients with PSO was 59.9 years (range: 18–93). PSOs were unilateral in 152 patients while 24 patients had multiple osteomas. Female/male ratio was 1.1/1. PSOs were most commonly located in the frontal sinuses. Frequencies of vertical concha bullosa, secondary middle turbinate, twisted uncinate, supraorbital ethmoid cell, intersinus septal cell, ethmoidomaxillary cell, Haller’s cell, frontal sinus hypoplasia and sphenoid sinus hypoplasia were significantly higher in the patient group compared to the control group.Conclusion:Higher or lower incidence rates of some anatomic variations in the patients with PSO could be explained by the possible effects of genetic and/or environmental factor. Additional studies are needed to evaluate these possible associations.

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

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Computed Tomographic Analysis

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

Can sinus anatomy predict quality of life outcomes and operative times of endoscopic frontal sinus surgery?

PurposeEndoscopic sinus surgery (ESS) can manipulate sinus anatomy, but with limitations due to skull base and orbit anatomy. These anatomical structures dictate the maximal extent of ESS in the frontal recess and may limit surgical extent or operative duration. This study investigates the impact of these anatomical constraints on operative time and quality-of-life (QOL) outcomes. Materials and methodsPatients with medically refractory chronic rhinosinusitis undergoing Draf IIa frontal sinus surgery were prospectively enrolled. Anatomic measurements of the frontal sinus anatomy were collected during computed tomography review and included: widest distance between the frontal beak and posterior table, narrowest point in the ethmoid bed, Keros height, presence of an anterior ethmoid artery on a mesentery, and presence of inter-sinus septal cells. Primary outcomes included mean operative time and improvement in SinoNasal Outcome Test (SNOT-22) survey scores. Results63 adult participants were enrolled and followed 13.8 (5.2) months on average. The ethmoid bed mean width was 7.2 (1.4) mm, the mean distance from frontal beak to the posterior table at widest was 9.0 (2.7) mm, and mean Keros height was 5.1 (1.8) mm. 49/63 (83.1%) of participants had inter-sinus septal cells and 30/63(50.8%) had anterior ethmoid arteries on a mesentery. Mean operative time was 121.5 (44.0) min while SNOT-22 scores significantly (p<0.001) improved 26.1 (21.6) on average. Anatomic measurements were not predictive of operative time or mean QOL change (p>0.050). ConclusionsFrontal sinus surgery is an effective treatment for a range of frontal and ethmoid sinus anatomy. Further study with larger sample size and measures of more restricted anatomy might elucidate treatment limitations of ESS.

Drainage pathways of the frontal sinus on oblique multi-planar reconstruction CT scans

Oblique reconstruction CT images of frontal sinus drainage pathways were created with ONIS which is free DICOM viewer software. By placing the slice line of the cross sectional image on the drainage pathway of the frontal sinus in the sagittal view, the key oblique CT image could be generated in 96.9% of 65 normal paranasal sinuses that showed the frontal sinus and its drainage pathway simultaneously in one slice. The route of the drainage pathway was divided by the line of the uncinate process, and three variations were defined as follows: (1) inside, (2) outside to inside, and (3) outside. Additionally, three variations of the upper attachment site of the uncinate process were defined as follows: (1) outside: orbital wall, (2) upside: skull base or intersinus septum of the frontal sinus, and (3) inside: middle turbinate. The uncinate process was attached to the "outside" in 66.7%, and all of them had the "inside" pathway of drainage. The rest of them in whom the uncinate process was attached to the "upside" or "inside" had a drainage pathway of "outside to inside" or "outside." The anatomical relations between the frontal sinus and the anterior ethmoid cells such as agger nasi cell, frontal ethmoidal cell and intersinus septal cell were reasonably explained with these variations in the drainage pathway. The key oblique CT image showing the frontal sinus drainage pathway is the imaginary plane of the surgical pathway of instruments while they are inserted into the frontal sinus. Therefore, using the oblique CT image together with the sagittal CT image, we can get valuable information about the three dimensional anatomy of the frontal sinus before and during frontal sinusotomy.

Treatment of chronic frontal sinusitis with difficult anatomy: A hybrid balloon technique in four cases.

The presence of frontal cells poses unique challenges when using endoscopic approaches. This study describes the use of a balloon dilation system as an aid for functional endoscopic sinus surgery (FESS) to access the frontal sinus in cases that would traditionally require open approaches. We present a case series of four patients with chronic rhinosinusitis refractive to medical management who underwent FESS with the aid of a balloon dilation system at a tertiary referral center. All patients had variant forms of frontal sinus anatomy. Surgical techniques will be described and use of the balloon system will be reviewed. All patients (aged 13–68 years) successfully underwent fontal sinusotomies with the assistance of a balloon dilation system, which was used in a variety of ways: to dilate the narrow infundibulum of a high intersinus septal cell, to remove an anteriorly located type III frontal sinus cell, to expand the natural frontal ostium in the presence of excessive agger nasi pneumatization, and to remove a type IV frontal sinus cell. All patients were spared an osteoplastic flap or trephination, and there were no intraoperative complications. No postoperative bleeding, infection, or cerebral spinal fluid leaks were reported. Balloon dilation in combination with standard frontal sinus dissection techniques may be beneficial for a select group of patients with complex frontal anatomy. In this series of patients, the balloon dilation system was used as a tool during FESS and eliminated the need for open approaches.

Three-Dimensional CT Reconstruction and Virtual Endoscopic Study of the Ostial Orientations of the Frontal Recess

Safe and efficient endoscopic frontal sinus surgery requires a thorough knowledge of the location of the frontal sinus outflow tract. This study was designed to describe the prevalence of the different frontal recess cells and 3D analysis by virtual endoscopy of their ostial orientation in relation to the frontal ostium. Fifty high-resolution CT scans (100 sides) of disease-free paranasal sinuses were reviewed using triplanar and virtual 3D analysis. The prevalence and ostial locations of the frontal recess cells and the relationship of the various ostia to the frontal sinus ostium were mapped and analyzed. The cell type, prevalence, and most common relationship of the cell's ostium to the frontal ostium were intersinus septal cells, 7% medial and anterior; Kuhn type 1 cells, 28%, lateral and anterior; Kuhn type 2 cells, 6%, anterior and lateral; Kuhn type 3 cells, 11%, medial or lateral; supraorbital ethmoid cells, 11%, posterior; suprabullar cells, 68%, posterior; and frontal bullar cells, 16%, posterior or lateral. In 35% of the sides, none of the aforementioned cell types were found. There were many blind recesses that were seen in all locations except anterolateral to the frontal ostium. Openings of adjacent pneumatized middle turbinates were often posteromedial to the frontal ostium. Agger nasi cells were present in at least 86%, opening lateral to frontal ostium. Frontal outflow tract mapping by virtual endoscopy and knowledge of the ostial configurations will help surgeons perform more efficient and accurate surgery particularly for minimally invasive approaches including balloon dilation.

Anatomical Analysis of the Frontal Recess Cells in Endoscopic Sinus Surgery-An Indian Perspective

AbstractSurgery of the frontal sinus has gone a full circle from intranasal procedures to destructive and disfiguring external operations and now back to intranasal procedures but with endoscopes. Endoscopic surgery of the frontal sinus has always been a challenging experience because of the narrowness of the area, poor visibility, variable anatomy and encroachment by accessory cells such as agger nasi, frontal, intersinus septal cells on the drainage pathway. With the developments in optical aids such as endoscopes, which provide an angled view, better and brighter illumination, sophistication in the designs of instrumentation and development of imaging techniques, a renewed interest has been created in this area, but the knowledge of anatomy of this area is poor and does not meet the demands of the present day endoscopic surgeon. Moreover, no studies are available on Indian subjects.Our main interest in the present study was to study the various air cells which encroach the area of frontal recess and would need surgical removal to provide a good drainage and ventilation.

Comparison between Three-Dimensional and Triplanar Computed Tomography Imaging of the Frontal Recess

Despite advances in endoscopic surgical techniques, management of frontal sinus disease remains challenging. Much of this is related to the complex nature of frontal recess anatomy. A thorough understanding of frontal recess anatomy is paramount for the safety and success of frontal sinus surgery. Three-dimensional (3D) computed tomography (CT) may allow surgeons to obtain a more complete preoperative assessment of frontal recess anatomy. The purpose of this study was to determine if reconstructed 3D CT images as an adjunct to conventional triplanar imaging provide additional information regarding the frontal recess anatomy. A prospective study was performed. Two otolaryngologists reviewed the CT scans of 25 patients referred for routine paranasal sinus disease. The findings from review of the triplanar CT images were compared with the findings from review of the 3D reconstructions. Each study was assessed for (1) frontoethmoidal cells, (2) agger nasi cell, (3) subrabullar and frontal bullar cells, (4) intersinus septal cell, (5) superior uncinate process attachment site, and (6) and frontal sinus outflow tract. The examiners rated the usefulness of each study to identify each of the aforementioned anatomic subsites using a modified 5-point Likert scale. Intersinus septal cells, supraorbital ethmoid cells, and the anterior-posterior dimension of the frontal sinus outflow tract were better defined on the reconstructed 3D CT images. Three-dimensional CT is a useful adjunct to the conventional triplanar studies for the evaluation of frontal sinus and recess anatomy. This technique can define certain anatomic variants more effectively than 2D multiplanar reconstructed images.

Frontal Sinus Inverted Papilloma: Surgical Strategy Based on the Site of Attachment

The surgical management of inverted papilloma (IP) involving the frontal sinus (FS) remains a challenge given the narrow confines of the frontal recess and the close proximity to critical structures. The objective of this study was to elucidate a surgical strategy for management of frontal sinus IP based on the site of attachment. A retrospective chart review was performed on 18 patients with FS IP treated at the Pusan National University Hospital and the Cleveland Clinic Foundation between 1998 and 2008. The mean age was 53.8 years with a male/female ratio of 13:5. The sites of tumor attachment included the medial wall (MW; six cases), posterior wall (PW; five cases), diffuse (all walls involved; five cases), intersinus septal cell (three cases), lateral wall (two cases), and anterior wall (two cases). IP involvement was unifocal in 10 cases and multifocal in 8 cases. Unifocal IP attached to the MW or PW was managed strictly by endoscopic frontal sinusotomy (EFS) in five of six cases (83%). Multifocal IP required endoscopic modified Lothrop (EML) and/or open approaches (endoscopic frontal trephination [EFT], four, osteoplastic flap [OPF], one) in seven of eight cases (88%). One additional patient with bilateral anterior table involvement required OPF. Four (22%) patients developed recurrences. Two were managed by EML, one was managed by EFS, and one was managed by EFT and EFS. Two patients developed cerebrospinal fluid leaks that were managed endoscopically without untoward effects. All patients were free of disease at the time of last evaluation with a mean follow-up of 36.6 months. Frontal sinus IP with MW or PW involvement can generally be managed by standard EFS. Tumors with multifocal involvement often require EML, along with adjunct EFT in selected cases. OPF can be avoided as the primary surgical approach in most patients with sinonasal papilloma of FS.

Management of Frontoethmoidal Cells in Frontal Recess Surgery

Frontal recess surgery is the most demanding and technically challenging part of endoscopic sinus surgery. The complexity of the anatomy and proximity with the skull base, the orbit, and the anterior ethmoidal artery often make the endoscopic approach to the frontal sinus drainage pathway difficult and increase the possibility of complications. The basic key structures to the frontal recess are the agger nasi cell and the superior fusion of the uncinate process. Above the agger nasi, the four categories of frontoethmoidal cells contribute to the complexity of the anterior wall of the frontal recess, and the bulla ethmoidalis, the suprabullar cells, and frontal bulla cells may also narrow the frontal sinus outflow. The supraorbital cells are often associated with low position of the anterior ethmoidal artery. Finally, the intersinus septal cells displace the frontal sinus drainage pathway posterolaterally, draining anteriorly into one or both middle meatuses. Clear understanding of the three-dimensional anatomy of the area is of upmost importance for a successful surgical approach. Thorough preoperative study of the CT scan with graphical reconstruction, as described in the literature, is the best way to achieve this. The concept will be presented with examples of various pathologies and anatomical configurations. The aid of frontal mini trephination and the use of image guidance will be outlined. Finally, the balloon dilatation of the frontal drainage pathway will be discussed, with reference to possible indications and contraindications.

Frontal recess cells: a rare cause of frontal sinus pneumocoele

A pneumocoele is a pathologically expanding, air-containing paranasal sinus. Pneumocoeles are uncommon entities, with very few cases reported in the literature. The most plausible aetiological theory is that of a one-way valve effect allowing air into the sinus under increased pressure without pressure equilibration. Review of a frontal sinus pneumocoele caused by a type III frontal cell and intersinus septal cell. We present a patient with chronic sinusitis who developed a pneumocoele of her left frontal sinus with erosion into her orbit. This patient was a habitual, chronic nose-blower with a large type III frontal cell adjacent to an intersinus septal cell. We propose the new theory that, in our patient, such cells formed a one-way valve, causing air-trapping and pathological expansion of the frontal sinus. To our knowledge, there are no previously published cases that establish an association between large frontal cells and expansion of a pneumocoele.

Interfrontal Sinus Septal Cell: A Cause of Obstructing Inflammation and Mucoceles

Recent interest in the origin and complications associated with frontal intersinus septal cells prompted us to review our material looking for cases of the uncommon occurrence of a mucocele developing within such a cell. The purpose of this article was to present the imaging findings on 4 cases of mucoceles arising within surgically proven frontal intersinus septal cells. A retrospective review of the case material in our department of otolaryngology since 2000 was made looking for cases of patients with surgically proven frontal intersinus septal cell mucoceles. Institutional review board approval for the review was obtained. Four cases were identified that also had CT and/or MR imaging studies. Examples of 4 additional classic frontal sinus mucoceles and 3 anterior ethmoid mucoceles were also identified for comparison. All 4 of the cases of frontal intersinus septal cell mucoceles had an expanded midline frontal sinus cell, which thinned the posterior and/or anterior frontal sinus tables. The classic frontal sinus mucoceles were either to the left or right side, and any table thinning was off midline. The ethmoid mucoceles were clearly centered below the frontal sinuses. The rare occurrence of a frontal intersinus septal mucocele can be diagnosed on CT and MR imaging studies, because its appearance in the midline is clearly distinct from the more common classic frontal sinus mucoceles that develop within the left or right frontal sinus proper. Distinction is also routinely made from large anterior ethmoid mucoceles.

The Frontal Intersinus Septal Air Cell: A New Hypothesis of Its Origin

Air cells are often seen within the frontal intersinus septum. These cells have traditionally been thought to arise from displaced ethmoid cells from the frontal recess. This study explores the possibility that such cells may actually be diverticula from the frontal sinuses themselves and not of a direct ethmoid origin. A prospective study of 200 consecutive CT scans in the coronal and axial planes was performed on patients without a history of recent trauma. The images were interpreted independently by a radiologist and an otolaryngologist. The CT studies were evaluated for the presence of a central intersinus septal air cell. If such a cell was identified, it was further classified as either being completely isolated from both frontal sinuses by a bony rim or as a communicating diverticulum from one of the frontal sinuses. If a central cell was present, it was also assessed for how much of the height of the intersinus septum it involved (lower one-half or full height). There was a complete concordance of the results between the 2 observers. An intersinus septal air cell was seen in 61 (30.5%) of the 200 cases, and 85.3% of these cells were clearly seen to communicate anteromedially with either one of the frontal sinuses or both frontal sinuses (3 cases). In 9 (4.5%) of the 200 cases, the central cell had no demonstrable connection to either frontal sinus. Of the 61 cases with a central cell, 55 (90.16%) of the cells occupied the full height of the septum, and 6 (9.84%) only involved the lower half of the septum. Contrary to the present convention that frontal intersinus septal cells originate as displaced ethmoid cells from the frontal recess, we found that most such cells are actually diverticula from the frontal sinuses themselves.

Multiplanar Computed Tomographic Analysis of Frontal Recess Cells

Frontal recess anatomy can be very complex, with accessory cells such as frontal, agger nasi, and intersinus septal cells encroaching on the frontal recess and possibly contributing to obstruction of the frontal sinus. In this study, we determined the prevalence of these cells and their relationship to frontal sinusitis in patients who have (revision group) and have not (primary group) had previous sinus surgery. Multiplanar computed tomographic images were reconstructed on a computer workstation to determine the presence of frontal, agger nasi, and intersinus septal cells and frontal sinusitis. We also measured the diameter and area of the frontal isthmus for each sinonasal cavity. We were able to retrieve 106 of 117 images from a surgical database encompassing the previous 2 years. Tertiary care academic practice of the senior author. Frontal cells were found in 25.5% of frontal recesses, including 29.6% of sides in the primary group and 21.9% of sides in the revision group. We identified 33.0% of patients as having unilateral or bilateral frontal cells. Type I cells were the most common cell (18.4% of primary sinuses). The presence of frontal sinusitis and the diameter and area of the frontal isthmus were not significantly different for those patients with compared with patients without frontal cells. Intact agger nasi cells were identified in 86.7% of primary sinuses and 53.5% of revision sinuses. There was no increased incidence of frontal sinusitis in patients with persistent agger nasi cells in the revision group. When we evaluated multiplanar reconstructions, we identified frontal cells in 33.0% of patients overall, which was more common than previously reported. The findings of agger nasi cells indicated that these cells were likely addressed in less than half of previous sinus procedures. However, frontal cells and retained agger nasi cells were not associated with a higher incidence of frontal sinusitis, and there was no association between the size of the frontal isthmus and the presence of frontal sinusitis. Although anatomic variations in the frontal recess are likely to play a role in frontal sinusitis, mucosal inflammatory processes are likely to be a much more important etiologic factor.

The Intersinus Septal Cell: Anatomic, Radiologic, and Clinical Correlation

Functional endoscopic frontal sinus surgery requires detailed knowledge of intranasal anatomy. Occasionally frontal sinusitis involves the intersinus septal cell (ISSC), which has not been described in the modern era of nasal endoscopy and computed tomography (CT). To study the ISSC, we reviewed 300 CT scans: 200 clinical and 100 cadaveric. We found ISSC in 70 (35%) of clinical scans, with six subjects having multiple ISSC. The cadaveric prevalence was slightly less at 31%. We further classified the ISSC according to the following criteria: type I, enclosed completely within the thin intersinus septum or bridging its entire inferior-superior extent; type II, bordered partially by this thin septum and partially by the thick septal base formed by the nasofrontal bone; type III, enclosed completely within the nasofrontal bone, often extending between frontal recesses rather than the actual sinuses. This report supplements our radiologic ISSC analysis with our experiences in five clinical cases.