Frontal Recess Cells in International Frontal Sinus Anatomy Classification (IFAC); Prevalence, Infection Incidence, and Relation to Frontal Sinus Infection in Chronic Sinusitis Patients

Frontal recess cells have many types with different sizes, arrangement, and extend. It plays an important role in successful functional endoscopic sinus surgery (FESS) as most causes of failure are related to it. Outline the prevalence of the frontal recess cells, pathological incidence of each cell regarding to frontal sinus pathology. Prospective study on 100 consecutive patients (200 sides) complaining from nasal and sinus symptoms which did not respond to medical management and indicated for FESS. Anterior group was infected in 30.8%; agger nasi cell (ANC) present in 97% (25.8% infected, 74.2% not infected), supra agger cell (SAC) present in 48% (39.6% infected, 60.4% not infected), supra agger frontal cell (SAFC) present in 11% (36.4% infected, 63.6% not infected). Posterior group was infected in 24.8%; supra bulla cell (SBC) present in 72% (30.6% infected, 69.4% not infected), supra bulla frontal cell (SBFC) present in 23% (17.4% infected, 82.6% not infected), supra orbital ethmoid cell (SOEC) present in 42% of cases (19% infected, 81% not infected). Medial group [frontal septal cell (FSC)] was present in 21% (33.3% infected, 66.7% not infected). FSC, SAC, SAFC, and SBC showed high infection rate in association with infected frontal sinus, while, the SOEC, ANC, and SBFC did not have such high infection rate. Frontal recess cells show no difference in their prevalence either if the frontal sinus infected or not, however their infection rate show significant difference.

Effectiveness of Functional Endoscopic Sinus Surgery in Surgical Management of Ethmoid Polyps

Background: Aim: To assess efficacy of functional endoscopic sinus surgery in surgical management of ethmoid polyps.Methods:One hundred twelve adult patients age ranged 18- 38 years of either gender with ethmoid polyps underwent FESS under general anesthesia. The extent of surgery was decided based on the findings in pre-operative CT scan of paranasal sinuses. Anterior ethmoidectomy, posterior ethmoidectomy, middle meatus antrostomy and clearance of frontal recess were performed in all the patients. Five functional criteria were evaluated as nasalobstruction , anosmia, rhinorrhea, post nasal drip, head ache and facial pain.Results:Pre- operative nasal obstruction percentage was 3.42 and post- operative ercentage was 2.10, Anosmia percentage was 2.14 and 1.15, Rhinorrhea percentage was 3.56 and 2.08 and ocular problem in 1 and synechia in 4 cases.Conclusions:Functional endoscopic sinus surgery found to be effective in management of ethmoid polyps and hence can be the treatment of choice.

The Effects of Suprabullar Pneumatization on the Orientation of Its Surrounding Anatomical Structures Relevant to the Frontal Drainage Pathway

Objective: The aim of this study was to evaluate the effects of suprabullar pneumatization on the orientation of the frontal sinus outflow structures and its association with the volume of anterior ethmoid sinus. Methods: A retrospective chart review of computed tomography of paranasal sinuses (CTPNS) images was conducted. A total of 370 sides of the CTPNS of 185 patients were analyzed. Results: The course of anterior ethmoidal artery (AEA) along the skull base (p = 0.04) and position of AEA at the second lamella (p = 0.04) was significantly associated with the type of suprabullar pneumatization. The AEA is expected to be lower at the skull base and at a longer distance from the second lamella with the increase in grading of the suprabullar pneumatization. The distance of AEA to the second lamella (p < 0.001) and third lamella (p = 0.04) was significantly different depending on the type of suprabullar pneumatization, which indicates AEA is expected to be at a longer distance from the second lamella and third lamella in higher grade suprabullar pneumatization. The type of suprabullar pneumatization has a significant but weak association with the anterior ethmoid sinus volume (p = 0.04). Conclusions: There is a significant effect of the type of suprabullar pneumatization on the orientation of the surrounding anatomical structures at the frontal recess. The type of suprabullar pneumatization is influenced by the anterior ethmoid sinus volume, which suggests it has a possible role in the frontal drainage pathway.

Remote Training of Functional Endoscopic Sinus Surgery With Advanced Manufactured 3D Sinus Models and a Telemedicine System

Objective: Traditionally, cadaveric courses have been an important tool in surgical education for Functional Endoscopic Sinus Surgery (FESS). The recent COVID-19 pandemic, however, has had a significant global impact on such courses due to its travel restrictions, social distancing regulations, and infection risk. Here, we report the world-first remote (Functional Endoscopic Sinus Surgery) FESS training course between Japan and Australia, utilizing novel 3D-printed sinus models. We examined the feasibility and educational effect of the course conducted entirely remotely with encrypted telemedicine software.Methods: Three otolaryngologists in Hokkaido, Japan, were trained to perform frontal sinus dissections on novel 3D sinus models of increasing difficulty, by two rhinologists located in Adelaide, South Australia. The advanced manufactured sinus models were 3D printed from the Computed tomography (CT) scans of patients with chronic rhinosinusitis. Using Zoom and the Quintree telemedicine platform, the surgeons in Adelaide first lectured the Japanese surgeons on the Building Block Concept for a three Dimensional understanding of the frontal recess. They in real time directly supervised the surgeons as they planned and then performed the frontal sinus dissections. The Japanese surgeons were asked to complete a questionnaire pertaining to their experience and the time taken to perform the frontal dissection was recorded. The course was streamed to over 200 otolaryngologists worldwide.Results: All dissectors completed five frontal sinusotomies. The time to identify the frontal sinus drainage pathway (FSDP) significantly reduced from 1,292 ± 672 to 321 ± 267 s (p = 0.02), despite an increase in the difficulty of the frontal recess anatomy. Image analysis revealed the volume of FSDP was improved (2.36 ± 0.00 to 9.70 ± 1.49 ml, p = 0.014). Questionnaires showed the course's general benefit was 95.47 ± 5.13 in dissectors and 89.24 ± 15.75 in audiences.Conclusion: The combination of telemedicine software, web-conferencing technology, standardized 3D sinus models, and expert supervision, provides excellent training outcomes for surgeons in circumstances when classical surgical workshops cannot be realized.

Supplements and refinements to current classifications and nomenclature of the fronto-ethmoidal transition region by systematic analysis with 3D CT microanatomy

Objective: The microanatomy of the fronto-ethmoidal transition region has been addressed in several classifications. CT stereoscopic imaging (3DCTSI) provides improved display and delineates three defined complex “spaces”, the Frontal Sinus/Frontal Recess Space, the Infundibular Space of the Ethmoid Uncinate Process, and the Ethmoid Bulla Space (FSRS, IS-EUP, EB), none of which were adequately described with the “cell” terminology. We present details on the 3D microanatomy, variability, and prevalence of these spaces. Methods: 3D stereoscopic imaging displays (3DCTSI) were created from 200 datasets. The images were analyzed and categorized by a radiologist (SJZ), and consultant otolaryngologists, focusing on 3D microanatomy of the fronto-ethmoidal transition, the frontal recess/frontal sinus, and drainage pathways, in comparison to established anatomical classification systems. Results: The anterior ethmoid is subdivided into seven groups with the following core properties and prevalence: 1. The horizontal roof of the IS-EUP is attached to the superior half of the frontal process of the maxilla (19%); 2. The IS-EUP extends into the frontal recess (6.5%); 3. The IS-EUP extends into the frontal recess and the frontal sinus (18.5%); 4. A bulla is seen in the medial frontal sinus (3%); 5. The ethmoid bulla and supra bullar space extend into the frontal sinus (7%); 6. Lamellae extend into the FSRS antero-superiorly (25%); 7. FSRS expansion expands below the upper half of the frontal process of the maxilla (FSRS) (21%). Conclusion: 3-D analysis of the detailed anatomy provides important new anatomic information with the increased focus on precision surgery in the region.