Frontal Sinus Ostium Research Articles

A Case of Orbital Emphysema Associated with Frontal Sinus Pneumocele

Orbital emphysema is usually caused by trauma and fracture of an orbital bone, allowing air to pass from the sinuses into the orbit. Orbital emphysema without any significant trauma is rare. We present a case of a 67-year-old-woman who complained of left exophthalmos without any history of trauma, sneezing, or sinus surgery. Computed tomography scanning showed left orbital emphysema protruding the eyeball forward. The left frontal sinus was remarkably enlarged associated with a partial defect of the orbital roof, allowing air entry into the orbit. In addition, the frontal sinus ostium was occluded with the mucocele that served as a one-way valve between the frontal and the ethmoidal sinuses. We performed frontal craniotomy and removed the mucocele and the inner table of frontal bone to communicate the frontal sinus with the nasal cavity. After operation, her exophthalmos was improved.

Analysis of the Agger nasi cell and frontal sinus ostium sizes using computed tomography of the paranasal sinuses

The Agger nasi cell (ANC) and the frontal sinus ostium (FO) are important structures that can influence the anatomy and physiology of the frontal recess. The aim of this study was to evaluate the presence and size of ANC and the FO and correlate them according to gender, race and among themselves. MethodA prospective study with 40 patients who underwent CT of the paranasal sinuses with sagittal reconstruction. Measurements: ANC (APAN) anteroposterior diameter, ANC (CCAN) craniocaudal diameter, ANC (LLAN) side-to-side diameter, anteroposterior diameter of the FO (APFO) and side-to-side diameter of the FO (LLFO). ResultsTwenty-two patients were male and 18 females, mean age 33.7 years. Most patients were white (45%), followed by browns (32.5%), blacks (20%) and asians (2.5%). The ANC was present in 98.7% of patients. There was statistical difference for APAN on females and LLAN on females and on the total sample. There were no differences for all measurements regarding gender, as well as the race. ANC and FO measurements showed positive correlation, but poor or very poor. ConclusionThe prevalence of ANC in our sample was high and did not show a statistically significant difference for most measurements. The correlation between measurements of ANC and the FO was poor or very poor.

Closure of the Frontal Sinus Ostium by a Block of Bone

Mucoceles are benign, slow-growing lesions. Frontal sinus mucoceles are caused by the obstruction of the sinus ostium and seromucous secretions fill the inside of the cyst. The size of the cyst and the destroyed sinus walls gradually expands. Cystic mass can lead to orbital or intracranial complications when it overflows beyond the boundaries of the sinus. In this manuscript, we presented an unexpected cause of frontal mucocele in which the closure of the frontal sinus ostium is caused by a block of bone. A case of orbital complications is presented.

High-resolution computed tomography analysis of the frontal sinus ostium: A pilot study

PurposeIdentification and exposure of the frontal sinus recess (FSR) during endoscopic sinus surgery (ESS) are challenging due to the variable anatomy, the narrow opening of the frontal sinus ostium (FSO), and the proximity of vital anatomic structures. Hence, a strong understanding of frontal sinus anatomy is required to prevent intracranial entry. Consistent and easily identifiable landmarks and measurements could assist safe entry into the FSO. In this study, we determine the distances from the columella and anterior nasal spine (ANS) to the nasofrontal beak (NFB) and anterior skull base (ASB) using high-resolution computed tomography (HRCT) scans. MethodsA radiographic analysis was performed at a tertiary care medical center. Measurements from the ANS to the NFB and ASB, and from the columella to the NFB and ASB were made using sagittal HRCT. Thirty-two HRCT scans were analyzed by three observers, and the mean distances and standard deviations were calculated. ResultsThe mean distance from the ANS to the NFB was 52.3±3.4mm in men and 47.7±3.5mm in women (p<0.0001). Mean distance from the ANS to the ASB was 61.8±4.1mm in men and 56.5±4.1mm in women (p<0.0001). Mean distance from the columella to the NFB was 58.9±2.3mm in men and 53.0±3.3mm in women (p<0.0001), and from the columella to the ASB was 67.9±3.7mm in men and 61.3±4.1mm in women (p<0.0001). ConclusionWhile performing FSR exposure in ESS, it is recommended to stay a distance of less than 66.9mm in men and 60.6mm in women from the columella to minimize intracranial complications.

Mapping the frontal sinus ostia using virtual endoscopy

To determine the relative location of the frontal sinus opening to other frontal cells using virtual endoscopy; and to assess whether the relative location of the frontal sinus ostium can be predicted. Retrospective analysis of high-resolution computed tomography scans from 50 adult patients without frontal sinus disease or previous sinus surgery. Using virtual endoscopy software, 100 frontal recesses were mapped for the presence and relative position of the frontal sinus ostium to the following cells: agger nasi (ANC); frontal bullar; frontal types 1, 2, and 3; supraorbital ethmoid; suprabullar; and intersinus septal cells. ANC and frontal type 3 cells were present in 92% and 45% of frontal recesses, respectively. All other cell types had a prevalence of ≤ 25%. Fifty percent of recesses had two rows of ostia anterior to posterior (AP), and the frontal opening was anterior in 52%. When there were three rows of cells AP (39%), the frontal opening was in the center in 64% of cases. Thirty-five percent of recesses had two rows of ostia medial to lateral (ML), and the frontal opening was medial 80% of the time. When there were three rows of openings ML (45%), the frontal opening was in the center 56% of the time. The frontal sinus recess is variable and complex. Virtual endoscopy can be used to analyze the frontal recess and assist in presurgical planning. Although there is variability in the ostial configuration present in the frontal recess, the probable position of the frontal sinus ostium can be predicted.

Frontal Infundibular Cells: Pathway to the Frontal Sinus

A frontal infundibular cell (FIC) is an uncommon anatomic variant of an anterior ethmoid pneumatization that originates from the frontal recess and typically extends into the lumen of the frontal sinus ostium. FICs may show several anatomic variants that impact the anatomy of the frontal recess. Familiarity with these variants is required for safe endoscopic sinus surgical procedures. We conducted a retrospective chart review, examining 1,040 frontal recesses in 520 adults with no frontal sinus disease, to explore the anatomy of the healthy frontal recess and to describe the prevalence of FICs in patients without a history of conditions that cause frontal pneumatization. Review of axial and coronal computed tomography data, which were reformatted for sagittal reconstruction, was performed at a computer workstation. Bent and Kuhn's classification was used to define types of FICs. We identified 167 patients (32.1%) as having unilateral or bilateral FICs. Type I infundibular cells were the most common type (found in 15.7% of the entire study population). Type II and type III FICs were found in 3.8% and 12.1%, respectively; type IV FICs were present in 0.4%. The FIC has not been emphasized as an important potential cause of frontal sinus obstruction in the radiology literature, but clinicians should specifically watch for it on all routine computed tomography of the frontal sinus. Fine-cut computed tomography scans aid in the identification of each individual cell and allow the surgeon to formulate a clear and precise surgical plan. A surgical plan with a thorough understanding of the anatomy enables confident dissection of this complex and difficult area.

Long‐term results after primary frontal sinus surgery

The objectives of this study were to evaluate the long-term frontal ostium patency rate and symptom improvement in patients undergoing primary endoscopic frontal sinusotomy (Draf 2A) and to assess the impact of patient factors, disease factors, and frontal ostium size on surgical outcomes. Retrospective chart review was used. Endoscopic assessment of frontal ostium patency and patient-reported symptoms were prospectively collected on patients who underwent primary frontal sinusotomy between January 2003 and December 2009. A total of 109 patients underwent primary endoscopic surgery on 210 frontal sinuses over the study period. The overall patency rate was 92%. Complete resolution of symptoms was noted in 85 patients (78%). Stenosis of the frontal sinus ostium correlated significantly with persistence of symptoms, infection, or polyp recurrence (p = 0.0066), and frontal ostium size (p < 0.03). No significant correlation could be found between the presence of eosinophilic mucin, asthma, polyposis, and smoking on patency or resolution of symptoms. To our knowledge, this is the largest study of primary endoscopic frontal sinus surgery in the literature. The technical and subjective measures of success are high. Frontal ostium size correlates with risk of stenosis of the frontal sinus. Patients with a stenosed frontal ostium and residual frontal sinus disease are more likely to be symptomatic or have endoscopic evidence of polyp recurrence or endoscopic evidence of persistent infection. Asthma, eosinophilic mucin chronic rhinosinusitis (EMCRS), allergy, and smoking do not appear to affect outcomes.

The Draf III Mucosal Grafting Technique

The Draf III procedure is an advanced surgical option for frontal sinus disease refractory to endoscopic frontal sinusotomy and is used to expose the anterior limit of resection of the skull base during endoscopic management of anterior skull base tumors. Our objective was to evaluate outcomes of a strategy using mucosal grafts to decrease postoperative closure. Prospective cohort. Tertiary care facility. Patients requiring a Draf III procedure were prospectively enrolled in the study. Demographics, reason for the procedure, percentage graft viability, and complications were recorded. The primary outcome measure was anterior-posterior (AP) diameter at 3 months. Mucosal grafting was performed during 29 Draf III procedures from 2008 to 2011. Twenty-seven patients (average age, 58 years) were available for measurement at 3 months (average postoperative follow-up, 15.4 months; range, 3-30 months). Reasons for the procedure included tumor (n = 14), chronic rhinosinusitis (CRS) with frontal ostium stenosis (n = 12), and trauma (n = 1). Average intraoperative AP diameter was 11.7 mm. All patients met the definition of success (<50% reduction in diameter), maintaining a patent combined frontal sinus ostium for the duration of follow-up (average diameter 10.8 mm at 3 months). Nine patients with CRS and frontal ostium stenosis had openings similar to the entire cohort (>1-year follow-up; average, 19.3 months) with significant symptom reduction (SNOT-22 preop 62.3 ± 20.8 vs 3 months 27.8 ± 14.8 and 1 year 21.4 ± 13.6; P < .0001). Cicatricial stenosis and osteoneogenesis are common following the Draf III procedure. This study indicates that the use of mucosal grafts may assist with postoperative stenosis and should be considered a routine strategy for preventing closure.

Role of nasal middle turbinectomy in nasal headache

Objective: To analyse the results of total resection of middle turbinate and partial resection of middle turbinate on nasal headache Design: Prospective study of chronic rhinogenic headache in 40 patients between January 2011 and December 2011, 25females and 15males,their age range was 18-55years,with a mean age of 32.4 years and their range of duration of headache was 1-20 years, with a mean duration of headache 6.125 years.The operation of total resection of middle turbinate has been performed in 40 ethmoidectomies & a control group of partial resection of middle turbinate has been performed by the same author in 40 ethmoidectomies. All the patients underwent pre-operative & post-operative assessment with a questionnaire of headache, using the visual analogue scale (VAS). Results: Total resection of middle turbinate showed complete cure of headache in 40 ethmoidectomies (100 percent) by questionnaire (subjective analysis). A control group of partial resection of middle turbinate showed complete cure in 20 ethmoidectomies (50 percent ), improvement (by 70%) in 4 ethmoidectomies (10 percent) & unchanged or worsened headache in 16 ethmoidectomies (40 percent) by subjective analysis at the last follow- up.The difference was statistically highly significant(P<0.01). Conclusion: Total resection of nasal middle turbinate in ESS is a good choice in chronic rhinogenic headache, not responding to usual medical anti-headache treatment & not septic. I. Introduction Each patient completed a questionnaire to elicit information on medications, medical history and the patient's subjective assessment of pre-operative & post-operative rhinogenic headache using standarized symptoms questionnaire quality of life score by Lund and Macky, the visual analogue scale (VAS). The scoring is range from 0 to 10 in which 0 represents no symptom & 10 represents greatest severity . 1 Local anesthetic test is done during the attack of headache. The nose is decongested then a piece of cotton soaked in xylocaine 2%, adrenaline 1:200.000 is put in the nose at any suspected contact area in the nose. The cotton is left for 5 minutes. Positive test is considered if the patient shows improvement of headache severity more than 50%. The simple presence of an intranasal pathology does not prove its role in headache causation.The etiologic role of this pathology should be confirmed by diagnostic local anesthetic testing as the source of pain. 2 The appropriate management of the middle turbinate remains controversial and arguments for its resection and for its preservation have been proposed. 3-5 Davis et al. reported that middle turbinectomy was the most important variable in predicting patency of the middle meatus antrostomy .6 A standard ESS Technique is done, the uncinate process is incised and removed & the middle turbinate is medialized with a freer elevator, the ethmoid bulla is entered & removed. A posterior ethmoidectomy is performed. The frontal sinus ostium is identified with a blunt curved suction .The natural ostium of the maxillary sinus is identified .The sphenoid sinus is entered medially and inferiorly as indicated. At this point, the procedure is essentially completed except for planning in regard to prevention of post-operative complications . 7 the present author has performed these procedures, as previously described, 7 on 40 patients with chronic rhinogenic headache. At a mean follow-up of 6 months. The patients were seen in the office 1 week post-operatively, any crusts are suctioned from the middle meatus & ethmoid, saline nasal irrigations were administrated. All the patients were followed up by endoscope and questionnaire of headache. The aim of this report was to review the cases of total resection of middle turbinate performed on nasal headache and compare the results with those of partial resection of middle turbinate performed by the same author at the same institution & period.

The Role of Endoscopic Surgery in the Treatment of Nasal Inverted Papilloma

1.1 Object: To explore the indications for surgical approach of nasal inverted papilloma based on clinical data. 1.2 Methods: In a retrospective study, clinical date of 72 patients with inverted papilloma operated at Anhui Provincial Hospital from 2000 to 2008. A preoperative CT scan was performed in all cases. 1.3 Result: There was no recurrence in any of the two T1 cases. T2--seven recurrence cases among 32 endoscopic cases and one among the four lateral rhinotomy, one among the three combined cases. T3--endoscopic: five recurrences in 22 cases, lateral rhinotomy: one in five cases, combine: one in two. T4--lateral rhinotomy: one case. 1.4 Conclusion: Based on the extensions and sites of the lesions, we should have different approaches to different cases. The endonasal microsurgial approach should be preferred to the cases with tumors localized in the ethmoid, sphenoid, maxilary sinus and frontal sinus ostium.

Evolution of the Draf III Procedure: Mucosal Grafting Technique

Objective: The Draf III procedure is an advanced surgical option for frontal sinus disease refractory to endoscopic frontal sinustomy and also delineates the anterior limit of skull base tumors during endoscopic resection. Our objective was to evaluate outcomes of a novel strategy utilizing mucosal grafts to decrease postoperative closure. Method: Patients with frontal sinus pathology requiring a Draf III procedure were prospectively enrolled in the study. Demographics, reason for the procedure, percent graft viability, and complications were recorded. The primary outcome measure was anterior-posterior (AP) diameter at 3 months. Results: Mucosal grafting technique was performed during 19 Draf III procedures from August 2008 to November 2010. Seventeen patients (average age 54 years) were available for endoscopic measurement at 3 months with an average postoperative follow-up of 13.5 months (4-24). Reasons for the procedure included tumor (n = 9), frontal ostium stenosis (n = 7), and trauma (n = 1). Fourteen patients (83%) had complete mucosal graft viability. Average intraoperative AP diameter was 12.3 mm. All patients maintained a patent combined frontal sinus ostium for the duration of follow-up with an average diameter of 10.9 mm at 3 months and no closure &gt;25% of intraoperative size. Conclusion: Cicatricial stenosis and osteoneogenesis are common following the Draf III procedure in up to 50% of individuals. The present study demonstrated that the mucosal grafting technique decreases Draf III stenosis when compared with historical series and should be considered a routine strategy for preventing postoperative closure.

The frontal intersinus septum takedown procedure

Unilateral frontal sinus obstruction presents a surgical challenge when outflow tract osteoneogenesis or dense scarring is present. Frontal sinus obliteration is often employed as a last resort, but this procedure has potential long-term complications. In some cases, endoscopic modified Lothrop or unilateral drillout procedures may be effective options; however, restenosis rates are often high. Here we report our experience using frontal intersinus septum takedown (FISST) to address unilateral obstruction while preserving the opposite frontal outflow tract. A retrospective review was performed of 12 patients with unilateral frontal sinus opacification due to irreversible frontal recess obstruction who underwent FISST. Surgical outcomes were assessed based on symptoms and computed tomography (CT) resolution of frontal sinus disease. All 12 patients undergoing FISST had significant improvement in their symptoms. Ten postoperative CT scans were available for review, all showing continued patency of the interfrontal connection, and nine out of 10 with resolution of radiographic frontal sinus disease. Eleven of the procedures were performed via trephination, and one was achieved endoscopically. In patients with one obstructed frontal sinus and a functional contralateral sinus, removal of the intersinus septum allows for adequate sinus drainage and significant clinical improvement. The success of FISST may be surprising given knowledge of mucociliary clearance patterns, but may be effective because of the naturally dependent position of the frontal sinus ostium.

A sheep model to investigate the role of fungal biofilms in sinusitis: fungal and bacterial synergy

The role of fungi in the spectrum of chronic rhinosinusitis (CRS) is poorly understood. Fungal biofilms have recently been discovered in CRS patients. We have developed an animal model for the investigation of sinonasal fungal biofilms. The role of type I hypersensitivity and pathogenic bacteria is presented. Thirty sheep were sensitized with fungal antigens-Aspergillus fumigatus and Alternaria alternata, or control. Endoscopic surgery was performed to expose both frontal sinus ostia-1 was occluded. Fungi with or without Staphylococcus aureus were inoculated into the sinus. Skin-prick tests assessed for fungal allergy. Fungal and S. aureus biofilms, histology, and culture rates were assessed. Forty-five percent of experimental sheep were sensitized to fungal antigen. Only 1 sinus inoculated with fungus developed minimal fungal biofilm. Eighty percent developed fungal biofilm when S. aureus was co-inoculated. The presence of hypersensitivity to fungus was not related to fungal biofilm development. Significant fungal biofilm only occurred when S. aureus was the co-inoculum. Hypersensitivity was not requisite. The relationship of S. aureus to fungal biofilms is of great clinical interest. Fungi may be opportunistic pathogens that simply require inflamed mucosa with weakened innate defenses; alternatively, a cross-kingdom synergy could be contributing to fungal proliferation.

The Effect of Expandable Polyvinyl Acetate Packing for Preventing Stenosis of the Frontal Sinus Ostium

The aim of this study was to evaluate the effect of repeated expandable polyvinyl acetate (EPA) packing for preventing stenosis of the frontal sinus ostium after patients undergo functional endoscopic sinus surgery (FESS). A nonrandomized, prospective study of 20 patients with chronic frontal sinusitis was conducted based on the Lund-Mackay scoring system. EPA was packed, for 3 days/week, in total, three times for 3 weeks, into the left frontal sinus ostium right after FESS. For the control, the right side frontal sinus ostium was left unpacked. After 6 months, the patency of the frontal sinus ostium was measured with a ruler under endoscopic guidance and the patency was classified as obstructed, stenotic, or patent according to the size. Obstruction developed in the right side in four patients and in the left side in two patients. Stenosis was found in the right side in eight patients and in the left side in one patient. The ostium of the frontal sinus was patent in the right side in 8 patients and patent in the left side in 17 patients. The sizes of the ostia were significantly different between the frontal sinuses on both sides 6 months after FESS (p < 0.05). The outcome of repeated EPA packing was favorable in patients undergoing FESS.

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.

Hidden unilateral agenesis of the frontal sinus: human cadaver study of a potential surgical pitfall

Purpose The aim of the study was to attract attention to the surgical significance of unilateral agenesis of the frontal sinus hidden by the overlapping expansion of the contralateral sinus toward the agenetic side. Materials and methods Retrospective review of endoscopic transnasal sinus dissections of 55 human cadavers (42, formalin fixated; 13, fresh frozen) was done in a tertiary care academic medical center. Surgical and radiologic findings were noted. Results Absence of right frontal sinus ostium in the presence of a connection between the right and left frontal sinuses was demonstrated in 2 (3.6%) cadavers. An absent and an incomplete septum between the frontal sinuses were also noted in these cadavers. No accompanying abnormality of other sinuses was found, and no evidence of previous sinus surgery was noted in these 2 cadavers. Conclusions If one of the frontal sinus ostia cannot be found during sinus surgery, although this sinus and its recess can be seen on the thick-sliced coronal computed tomographic (CT) scans, keep in mind that it may be (3.6%) an agenetic frontal sinus hidden by the extensive pneumatization of the contralateral sinus that is crossing the midline. It may not be possible to foresee this variant preoperatively by endoscopic examinations or thick-sliced CT scans. If there is suspicion, thin-sliced CT scans with reconstruction will be ideal to confirm the agenesis of the frontal sinus and to avoid complications. In the presence of such variant of frontal sinus, 1-sided successful frontal sinusotomy is adequate because this sinus or cell will already be drained through the treated frontal recess.

Balloon Catheter Dilatation for Frontal Sinus Ostium Stenosis in the Office Setting

Frontal sinus ostium stenosis (FSOS) is problematic even for expert surgeons. Balloon catheter (BC) technology has been recently introduced to rhinology. The aim of this study is to assess technical feasibility and effectiveness of BC dilatation of FSOS in the office setting. This retrospective, multi-institutional case series describes all patients who underwent BC dilatation of FSOS in the office setting in the year ending December 31, 2007. Six adult patients underwent a total of seven BC dilatations of FSOS in the clinical setting. The pretreatment ostium size was 1-2 mm. Four of the dilatations were performed with a 5-mm lacrimal BC (LacriCATH, Quest Medical, Allen, TX) and three dilatations were executed with a 7-mm sinus BC (SinuCATH, Quest Medical). All procedures were performed using topical anesthesia only. No complications occurred. Five of the six dilated FSOS dilatations were deemed successful after one BC dilatation. One ostium contracted >50% and required repeat BC dilatation. All ostia have remained patent with a follow-up range of 4-9 months. No subject has required formal surgical revision. This preliminary report describes BC of FSOS in the office setting. The technique may serve as a safe and feasible alternative, potentially avoiding formal revision sinus surgery in select patients.

Rapports endoscopiques entre l’ostium du sinus frontal et l’artère ethmoïdale antérieure : implications chirurgicales

Objectives The anterior ethmoidal artery represents a major danger in the dissection of the anterior ethmoid roof. In addition to hemorrhage, its injury exposes the patient to the risk of orbital haematoma and requires intraoperative and postoperative vigilance. The goal of this study was to describe the anatomical relationship between the frontal sinus ostium and the anterior ethmoidal artery, such as they are observed with the endoscope during nasalization. Materials and methods Consecutive patients with no surgical history or agenesia of the frontal sinuses, with an indication for ethmoidal complete exenteration with ablation of the mucous membrane (nasalization), were included in a prospective descriptive study. When dissection of the anterior ethmoidal roof was finished, the relationship between the frontal sinus ostium and the anterior ethmoidal artery were filmed and drawn on a diagram during surgery. A photograph of the relationship between the frontal sinus ostium and anterior ethmoidal artery was selected afterward from the film. Results Sixty-eight ethmoids were operated (30 bilateral, eight unilateral) with no complications. The anterior ethmoidal artery was visible in 60 cases (88%), 31 out of 34 cases on the left side (45%) and 29 out of 34 cases on the right side (43%); it was not visible in eight cases (12%), three cases on the left (4.5%) and five cases on the right (7.5%). In the most frequent anatomical configuration (45 cases, 66%), the frontal sinus ostium was separated from the anterior ethmoidal artery by a single ethmoidal cell. The other anatomical configurations were: presence of two cells between the frontal sinus ostium and the anterior ethmoidal artery in 11 cases (16%), and three cells in one case (1%) or absence of the ethmoidal cell between the frontal sinus ostium and the anterior ethmoidal artery (the anterior ethmoidal artery was located on the posterior wedge of the frontal ostium) in three cases (4%). The comparison of the 30 bilateral cases showed a symmetrical relationship between the frontal sinus ostium and the anterior ethmoidal artery in 20 cases (67%). Conclusions These data are addressed to surgeons seeking the anterior ethmoidal artery starting from the frontal sinus ostium. Localization of the frontal sinus ostium, which can be achieved by retrograde cannulation of the frontal sinus or using a transcutaneous frontal drain, appears to be a reliable technique to dissect the roof of the anterior ethmoid and locate the anterior ethmoidal artery.

Estudo da anatomia do recesso frontal por meio de dissecção endoscópica em cadáveres

INTRODUÇÃO E OBJETIVO: O óstio do seio frontal freqüentemente apresenta difícil reconhecimento devido a estruturas anatômicas que encobrem sua visibilização. O objetivo principal desse estudo foi identificar e descrever as estruturas anatômicas do recesso frontal que dificultam o reconhecimento do óstio do seio frontal. CASUÍSTICA E MÉTODOS: Foi realizado um estudo prospectivo por meio de dissecção endoscópica consecutiva de 32 cadáveres (59 fossas nasais), 10 (31,25%) do sexo feminino e 22 (68,75%) do sexo masculino. Após exérese endoscópica da porção inferior do processo uncinado, com a preservação da sua inserção superior, avaliamos quais estruturas anatômicas necessitavam ser removidas até a completa visibilização endonasal do óstio do seio frontal. RESULTADOS E CONCLUSÃO: A visibilização do óstio do seio frontal após a exérese da porção inferior do processo uncinado foi possível em apenas 11 (18,64%) fossas nasais. O processo uncinado (recesso terminal) representou a principal estrutura anatômica que dificultou o reconhecimento endonasal do óstio do seio frontal, ocorrendo em 45 (76,27%) fossas nasais, seguido pela bolha etmoidal (16,95%) e a célula agger nasi (6,78%).

Frontal recess anatomy study by endoscopic dissection in cadavers

The frontal sinus ostium is frequently difficult to recognize because of anatomical structures that hide it. The objective of the present study was to identify and describe the frontal recess anatomy that impairs the endoscopic recognition of the frontal sinus ostium. A prospective study was conducted by consecutive endoscopic dissections of 32 cadavers (59 sides), 10 (31.25%) females and 22 (68.75%) males. After resection of the lower portion of the uncinate process, with preservation of its upper insertion, we evaluated which anatomical structures needed to be removed for complete visualization of the frontal sinus ostium. Visualization of the frontal sinus ostium after resection of the lower portion of the uncinate process was possible in only 11 (18.64%) nasal cavities. The uncinate process (terminal recess) was the main anatomical structure that impaired the recognition of the frontal sinus ostium, present in 45 (76.27%) nasal cavities, followed by the ethmoid bulla (16.95%) and agger nasi cells (6.78%).