The Frontal Sinus and Frontal Recess: Anatomical, Radiological and Surgical Concepts

Abstract Introduction The frontal sinus (FS) is the most complex of the paranasal sinuses due to its location, anatomical variations and multiple clinical presentations. The surgical management of the FS and of the frontal recess (FR) is technically challenging, and a complete understanding of its anatomy, radiology, main diseases and surgical techniques is crucial to achieve therapeutic success. Objectives To review the FS and FR anatomy, radiology, and surgical techniques. Data Synthesis The FS features a variety of anatomical, volumetric and dimensional characteristics. From the endoscopic point of view, the FR is the point of greatest narrowing and, to have access to this region, one must know the anatomical limits and the ethmoid cells that are located around the FR and very often block the sinus drainage. Benign diseases such as chronic rhinosinusitis (CRS), mucocele and osteomas are the main pathologies found in the FS; however, there is a wide variety of malignant tumors that can also affect this region and represent a major technical challenge to the surgeon. With the advances in the endoscopic technique, the vast majority of diseases that affect the FS can be treated according to Wolfgang Draf, who systemized the approaches into four types (I, IIa, IIb, III). Conclusion Both benign and malignant diseases that affect the FS and FR can be successfully managed if one has a thorough understanding of the FS and FR anatomy, an individualized approach of the best surgical technique in each case, and the appropriate tools to operate in this region.

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A Radiological Study Assessing the Prevalence of Frontal Recess Cells and the Most Common Frontal Sinus Drainage Pathways

American Journal of Rhinology and Allergy ◽

10.1177/1945892419826228 ◽

2019 ◽

Vol 33 (3) ◽

pp. 323-330 ◽

Cited By ~ 3

Author(s):

Luan V. Tran ◽

Ngoc H. Ngo ◽

Alkis J. Psaltis

Keyword(s):

Frontal Sinus ◽

Building Blocks ◽

Sinus Surgery ◽

Virtual Planning ◽

Frontal Recess ◽

Planning Software ◽

Anatomical Classification ◽

Computed Tomography Scans ◽

Vietnamese Population ◽

Sinus Drainage

Background To date, there are numerous studies documenting the prevalence of frontal recess cells, but only 1 study using the newly developed International Frontal Sinus Anatomical Classification (IFAC) system. The identification of the frontal cells and their influence on the frontal drainage pathway plays an important role in endoscopic frontal sinus surgery. Objective The aim of this study is to document the radiological prevalence of various types of frontal cells, as classified by IFAC and the most common frontal sinus drainage pathways based on its anatomic relationships with these cells. Methods Using a novel preoperative virtual planning software (Scopis Building Blocks), consecutive computerized tomography scans of the sinuses of patients were analyzed for the prevalence of frontal cells, as classified by the by IFAC, and the frontal sinus drainage pathways at the Ear Nose Throat Hospital of Ho Chi Minh City, Vietnam. Results In this study, 208 computed tomography scans of consecutively selected frontal sinuses of 114 patients were included for analysis. The agger nasi cell was present in 95.7% of reviewed scans. The frontal cells prevalence was as follows: supra agger cell (SAC): 16.3%, supra agger frontal cell (SAFC): 13%, supra bulla cell (SBC): 46.2%, supra bulla frontal cell (SBFC): 4.3%, supra orbital ethmoid cell: 17.3%, and frontal septal cell: 10.6%. The most common frontal sinus pathway type in relation to frontal cells was medial to SAC (70.6%), medial to SAFC (81.5%), anterior to SBC (88.5%), and anterior to SBFC (100%). In cases that had 2 frontal cells group, the drainage pathway was medial to SAC/SAFC and anterior to SBC/SBFC in most cases. Conclusion This study documents the prevalence of frontal cells (classified by IFAC) using a novel preoperative virtual planning software in the Vietnamese population. It demonstrates predominantly medial anteromedial frontal drainage pathways as related to these frontal cells.

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Frontal Sinus Fractures: Current Concepts

Craniomaxillofacial Trauma & Reconstruction ◽

10.1055/s-0029-1234020 ◽

2009 ◽

Vol 2 (3-4) ◽

pp. 161-175 ◽

Cited By ~ 26

Author(s):

E. Bradley Strong

Keyword(s):

Frontal Sinus ◽

Treatment Algorithm ◽

Surgical Techniques ◽

Treatment Strategies ◽

Cerebrospinal Fluid Leak ◽

Current Treatment ◽

Frontal Recess ◽

Patient Morbidity ◽

Frontal Sinus Fracture ◽

Key Steps

Frontal sinus injuries may range from isolated anterior table fractures resulting in a simple aesthetic deformity to complex fractures involving the frontal recess, orbits, skull base, and intracranial contents. The risk of long-term morbidity can be significant. Optimal treatment strategies for the management of frontal sinus fractures remain controversial. However, it is critical to have a thorough understanding of frontal sinus anatomy as well as the current treatment strategies used to manage these injuries. A thorough physical exam and thin-cut, multiplanar (axial, coronal, and sagittal) computed tomography scan should be performed in all patients suspected of having a frontal sinus fracture. The most appropriate treatment strategy can be determined by assessing five anatomic parameters including the: frontal recess, anterior table integrity, posterior table integrity, dural integrity, and presence of a cerebrospinal fluid leak. A well thought out management strategy and meticulous surgical techniques are critical to success. The primary surgical goal is to provide a safe sinus while minimizing patient morbidity. This article offers an anatomically based treatment algorithm for the management of frontal sinus fractures and highlights the key steps to surgical repair.

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Radiological study of the myriad variations in frontal sinus anatomy: an institutional study

International Journal of Otorhinolaryngology and Head and Neck Surgery ◽

10.18203/issn.2454-5929.ijohns20190762 ◽

2019 ◽

Vol 5 (2) ◽

pp. 369

Author(s):

Sreenivas Vepamininti ◽

Soumya M. Seetharam ◽

Jomy George ◽

Hemanth Vamanshankar ◽

Poonam K. Saidha

Keyword(s):

Paranasal Sinuses ◽

Frontal Sinus ◽

Chronic Sinusitis ◽

Signs And Symptoms ◽

Anatomical Variations ◽

Sinus Disease ◽

Radiological Study ◽

Medical College ◽

Sinus Drainage ◽

Axial Ct

Background: The frontal sinus is a challenging area for endoscopic surgeons. The variations in the frontal sinus differs so much among individuals that there are forensic applications. A detailed radiological study of the sinus is important for understanding the pathophysiology of sinusitis and as a prerequisite for frontal sinus drainage procedures. Aims and objectives were to document the anatomical variations of the frontal sinus (radiological) and to correlate the variations with the signs and symptoms of sinusitis.Methods: Coronal and axial CT paranasal sinuses scans of 30 consecutive patients who attended the Otolaryngology clinic OPD in St. John’s medical college and hospital, Bangalore, India with signs/symptoms of chronic sinusitis were evaluated between January to July 2018. Results: The average frontal sinus diameter in patients with sinusitis was 6.65 mm. The prevalence of frontal cells in our study was 48%. Agger nasi cells were the most common cells seen. Frontal sinus disease was found in 72% of the studied sides in the scans.Conclusions: Frontal sinus anatomy varies with different ethnicities. It is very important to study the frontal sinus anatomy before exploring the sinus for disease clearance and avoid surgical complications.

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3D CT stereoscopic imaging: an improved anatomical understanding of the anterior ethmoid sinus and frontal sinus drainage pathway

Rhinology online ◽

10.4193/rhin20.061 ◽

2020 ◽

Vol 3 (3) ◽

pp. 202-220

Author(s):

S.J. Zinreich ◽

F.A. Kuhn ◽

N.R. London Jr. ◽

D. Kennedy ◽

M. Solaiyappan ◽

...

Keyword(s):

Frontal Sinus ◽

Three Dimensional ◽

Uncinate Process ◽

Small Sample ◽

Middle Meatus ◽

Stereoscopic Imaging ◽

X Ray ◽

Frontal Recess ◽

Sinus Drainage

OBJECTIVE: The objective of this presentation is to display a series of new anatomical concepts and terms regarding the frontal si- nus, its drainage pathway and cells vs. spaces of the anterior ethmoid, based on Three-Dimensional Computer X-ray Tomography Stereoscopic Imaging (3DCTSI) and contrast these concepts to those reported in the current literature. METHODS: Given the new anatomic observations provided by 3DCTSI, and the widespread anatomic variations a small sample was initially selected to describe our observations. Six exemplary cases according to the “Classification of Fronto-Ethmoidal cells” by Kuhn, Bent et al., Lee et al., expanded by Wormald et al., and adopted by Ramakrishnan et al., Huang et al., and Void et al. (1-7) were chosen to illustrate our detailed anatomic observations. Additional observations and data of prevalence identified in a larger series will follow. RESULTS and CONCLUSION: Conceptually, the anterior ethmoid “cells” are in essence “spaces” with openings that communicate with the middle meatus and/or the ethmoidal infundibulum. The frontal sinus and frontal recess are a united and continuous three-dimensional, irregularly shaped space, the Frontal Sinus/Recess Space (FSRS). The uncinate process has two segments: the Ethmoidal Uncinate Process (EUP), which encompasses the Infundibular Space of the EUP (IS-EUP), currently known as the Agger Nasi cell; and the Turbinal Uncinate Process (TUP), which borders the Turbinal Infundibulum (TI) medially. The superior attach- ment of the EUP will be detailed in each of the six cases (Table 2). The middle meatus and infundibular passages are the drainage pathways from the frontal sinus and maxillary sinus to the nasal cavity.

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

American Journal of Rhinology and Allergy ◽

10.2500/ajra.2009.23.3350 ◽

2009 ◽

Vol 23 (5) ◽

pp. 502-505 ◽

Cited By ~ 7

Author(s):

Seth J. Isaacs ◽

Parul Goyal

Keyword(s):

Computed Tomography ◽

Frontal Sinus ◽

Three Dimensional ◽

Surgical Techniques ◽

Ct Images ◽

Outflow Tract ◽

Sinus Surgery ◽

3D Ct ◽

Sinus Disease ◽

Frontal Recess

Background 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. Methods 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. Results 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. Conclusion 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.

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Endoscopic approach to the frontal sinus with modified Lothrop technique. Outcomes in a large Argentinean center

Journal of Otolaryngology-ENT Research ◽

10.15406/joentr.2019.11.00424 ◽

2019 ◽

Vol 11 (2) ◽

pp. 140-143

Author(s):

Carlos S Ruggeri ◽

Sebastian Aragon ◽

Ana Laura Cajelli ◽

Lourdes Principe ◽

Agustin Martinez Font ◽

...

Keyword(s):

Surgical Technique ◽

Frontal Sinus ◽

Malignant Tumors ◽

Fungal Sinusitis ◽

Modified Technique ◽

Allergic Fungal Sinusitis ◽

Transnasal Approach ◽

History Of ◽

Sinus Drainage ◽

Unilateral Block

Objectives: To determine the permeability of the frontal drainage obtained by the modified Lothrop surgical technique. Study design: Descriptive and retrospective. Methods: Patients treated with modified Lothrop technique to widening the frontal recess drainage pathway which was obstructed by inflammatory or tumor diseases in the Rhinology section of the Hospital Italiano in Buenos Aires were included between April 2011 and December 2017. Patients with minor permeabilizations were excluded (Draf I-II). Results: 16 patients were treated, 7 women and 9 men, the youngest was 24 and the oldest 90. The average age was 56 years. The etiologies of diseases affecting the frontal sinus were allergic fungal sinusitis (2/16), recurred frontal mucocele with a history of Draf 2 (3/16), recurred frontal mucocele to external surgery with obliteration (1/16), frontal mucocele, nasal polyposis and cystic fibrosis (1/16), previous frontal sinusitis surgery (4/16), frontal mucopioceles (2/16) and malignant tumors originating in the ethmoid and frontal sinus (3/16). An unilateral block drainage of the frontal by mucosal hyperplasia was diagnosed in a patient, caused by her allergic fungal rhinosinusitis 5 years after Lothrop surgery. Moreover the patient was operated again by transnasal approach permeabilizing the frontal sinus. Another patient had a total obstruction of the frontal drainage and was successfully repeated with the same surgical technique. The other patients had permeable frontal drainage and were asymptomatic during the average follow-up of 3.5years. Conclusion: The obtained permeability of the frontal sinus drainage with Lothrop modified technique was 87.50% (14/16). With rescue endonasal assisted surgery, frontal sinus patency was 100%.

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Teaching Residents Frontal Sinus Anatomy Using a Novel 3-Dimensional Conceptualization Planning Software-Based Module

American Journal of Rhinology and Allergy ◽

10.1177/1945892418801264 ◽

2018 ◽

Vol 32 (6) ◽

pp. 526-532 ◽

Cited By ~ 2

Author(s):

Philip G. Chen ◽

Ahmed Bassiouni ◽

Christine B. Taylor ◽

Alkis J. Psaltis ◽

Abdulaziz Alrasheed ◽

...

Keyword(s):

Frontal Sinus ◽

Simulation Training ◽

Third Party ◽

Ct Scans ◽

Educational Module ◽

3 Dimensional ◽

Frontal Recess ◽

Planning Software ◽

Cell Structures ◽

Sinus Drainage

Background The Frontal Sinus Masterclass (FSMC) is an effective method for teaching frontal sinus anatomy. A third party developed new software using the same 3-dimensional building block concept. The authors sought to determine whether the use of the software for the educational module yielded similar results to the original FSMC, which used wooden blocks. Methods The study was performed at a sinus course for residents. A precourse test assessed the ability to decipher frontal sinus anatomy prior to the course. Computed tomography (CT) scans of the sinuses were evaluated in triplanar view, and participants attempted to reconstruct the anatomy using the new software. Subsequently, the course instructor explained the anatomy and showed a short corresponding surgical video of the frontal sinusotomy. Cases progressed in anatomical difficulty and inflammatory load. A postcourse test determined knowledge after the course. Results In sum, 50 residents completed the pre- and postcourse tests. Overall scores increased from 60.5% to 65.2% ( P = .004). Subanalysis also demonstrated improved ability to locate the frontal drainage pathway from 32.5% to 46% ( P = .011) and label the frontal recess cell structures from 64% to 67.6% ( P = .045). Conclusion There is minimal literature on proven methods for teaching frontal sinus anatomy. Objectively, participants of the modified FSMC simulation training using new software improved their ability to recognize cells of the frontal recess on CT scans. They especially exhibited better localization of the frontal sinus drainage pathway. Subjectively, participants reported benefit from the course and felt they would be better surgeons.

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Endoscopic Anatomic Characterization of the Frontal Recess and Its Implications in Frontal Sinus Surgery

ORL ◽

10.1159/000114530 ◽

2008 ◽

Vol 70 (2) ◽

pp. 84-90 ◽

Cited By ~ 1

Author(s):

Zhou Bing ◽

Han Demin ◽

Liu Huachao ◽

Huang Qian ◽

Zhang Luo ◽

...

Keyword(s):

Frontal Sinus ◽

Sinus Surgery ◽

Frontal Recess ◽

Frontal Sinus Surgery

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Frontal Sinus Drainage in Acute Pediatric Sinusitis With Intracranial Complications

American Journal of Rhinology and Allergy ◽

10.1177/1945892421991311 ◽

2021 ◽

pp. 194589242199131

Author(s):

Stephen R. Chorney ◽

Adva Buzi ◽

Mark D. Rizzi

Keyword(s):

Surgical Procedures ◽

Frontal Sinus ◽

Case Series ◽

Primary Objective ◽

Acute Sinusitis ◽

Intracranial Abscess ◽

Repeat Surgery ◽

Initial Surgery ◽

Intracranial Complications ◽

Sinus Drainage

Background The indication for frontal sinus drainage is uncertain when managing pediatric acute sinusitis with intracranial complications. Objective The primary objective was to determine if addressing the frontal sinus reduced need for subsequent surgical procedures in children presenting with acute sinusitis complicated by intracranial abscess. Methods A case series with chart review was performed at a tertiary children’s hospital between 2007 and 2019. Children under 18 years of age requiring surgery for complicated acute sinusitis that included the frontal sinus with noncontiguous intracranial abscess were included. Outcomes were compared among children for whom the frontal sinus was drained endoscopically, opened intracranially, or left undrained. Results Thirty-five children with a mean age of 11.1 years (95% CI: 9.9-12.3) met inclusion. Most presented with epidural abscess (37%). Hospitalizations lasted 12.9 days (95% CI: 10.2-15.5), 46% required a second surgery, 11% required three or more surgeries, and 31% were readmitted within 60 days. Initial surgery for 29% included endoscopic frontal sinusotomy, 34% had a frontal sinus cranialization and 37% did not have any initial drainage of the frontal sinus. Groups were similar with respect to demographics, severity of infection, need for repeat surgery, length of stay, and readmissions (p > .05). Further, persistence of cranial neuropathies, seizures, or major neurological sequelae after discharge were no different among groups (p > .05). Conclusion Drainage of the frontal sinus, when technically feasible, was not associated with reduced surgical procedures or increased complications and there is unclear benefit on measured clinical outcomes.

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Molecular Determinants of Soft Tissue Sarcoma Immunity: Targets for Immune Intervention

International Journal of Molecular Sciences ◽

10.3390/ijms22147518 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7518

Author(s):

Marcella Tazzari ◽

Laura Bergamaschi ◽

Alessandro De Vita ◽

Paola Collini ◽

Marta Barisella ◽

...

Keyword(s):

Soft Tissue ◽

Malignant Tumors ◽

Soft Tissue Sarcomas ◽

Point Of View ◽

Molecular Features ◽

Molecular Determinants ◽

Genetic Landscape ◽

Current Therapies ◽

Cumulative Evidence

Soft tissue sarcomas (STSs) are a family of rare malignant tumors encompassing more than 80 histologies. Current therapies for metastatic STS, a condition that affects roughly half of patients, have limited efficacy, making innovative therapeutic strategies urgently needed. From a molecular point of view, STSs can be classified as translocation-related and those with a heavily rearranged genotype. Although only the latter display an increased mutational burden, molecular profiles suggestive of an “immune hot” tumor microenvironment are observed across STS histologies, and response to immunotherapy has been reported in both translocation-related and genetic complex STSs. These data reinforce the notion that immunity in STSs is multifaceted and influenced by both genetic and epigenetic determinants. Cumulative evidence indicates that a fine characterization of STSs at different levels is required to identify biomarkers predictive of immunotherapy response and to discover targetable pathways to switch on the immune sensitivity of “immune cold” tumors. In this review, we will summarize recent findings on the interplay between genetic landscape, molecular profiling and immunity in STSs. Immunological and molecular features will be discussed for their prognostic value in selected STS histologies. Finally, the local and systemic immunomodulatory effects of the targeted drugs imatinib and sunitinib will be discussed.

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