Endoscopic repair of nasal septal perforation with anterior ethmoidal artery flap using tunnel technique.

PURPOSE: Septal perforations (SPs) present a distinct challenge. There are many described surgical approaches with variable success rates. The goal of this study is to describe a new technique in repairing SP. METHODS: A case series of eighteen patients with anterior septal perforation who underwent endoscopic repair with the "tunnel technique" based on anterior ethmoid artery flap (AEA) were analyzed. Demographic data, etiology, size of perforation, and success rate were collected. RESULTS: Eighteen cases with male predominance (67%) were enrolled from 2019 to 2022. The average perforation size was 1.5 cm (0.5- 3.6 cm). The success rate of complete SP closure was 94% (n = 17/18) with no complications after surgery. The patients were followed up for 7 ± 5.2 months. CONCLUSIONS: AEA flap reconstruction with the tunnel technique is associated with favorable outcomes in SP closure. The tunnel technique provides a useful flap bolster and minimizes the use of other supportive measures. This technique offers an addition to other techniques for septal perforation repair. LEVEL OF EVIDENCE: Level 4.

Characteristics of Posterior Ethmoidal Artery and Its Relationship with Anterior Ethmoidal Artery and Skull Base on CT Scan.

Objective: Investigation of the anterior and posterior ethmoidal arteries on computed tomography (CT) scans of the sinuses before and during surgery is important, especially for inexperienced surgeons. The aim of this study was to examine the anatomical characteristics of the posterior ethmoid artery in Vietnamese and the distance from the posterior ethmoid artery to the anterior ethmoid artery and the skull base on CT scan. Methods: A cross-sectional study was conducted involving patients aged ≥18 years who underwent CT scan imaging at the Ear, Nose and Throat Hospital of Ho Chi Minh City from February 2023 to July 2023. Results: There were 100 patients in this study, of whom 51% (51/100) were female and 49% (49/100) were male. Patient ages ranged from 20 to 84 years. Their average age was 40.92±14.65 years. The distance on CT scan between the posterior and anterior ethmoidal arteries was 13.98±1.95 mm (9.3 to 18.6 mm). This distance in males was significantly higher than female (p=0.001). However, there is no difference in this distance between the left and right side (p=0.67). The distance between the posterior ethmoid artery and skull base ranged from 0 to 5.4 mm. The average distance between the posterior ethmoidal artery and skull base on CT scan was 0.95±0.94 mm. The diameter of the posterior ethmoid artery was 0.57-0.91 mm. The average diameter of the posterior ethmoidal artery on CT scan was 0.76±0.09 mm. Conclusion: The characteristics of the posterior ethmoid artery should be considered when examining the CT scan. Distance from the posterior ethmoid This study provides useful information on the characteristics of the posterior ethmoid artery on CT scans, which can be applied in endoscopic sinus surgery and skull base surgery.

A Detailed Assessment of Variations of Ethmoid Roof, Olfactory Fossa, and Anterior Ethmoidal Artery on CT Scan of Paranasal Sinuses of 200 Patients.

To study and analyse the variations in ethmoid roof anatomy and estimate the anatomical location and variations of AEA on CT scans. The study is conducted on 200 patients for detailed analysis of the olfactory fossa (OF) depth, supraorbital pneumatisation, and AEA location and distance from the skull base. In our study, Keros type II was predominant type seen followed by type I. Asymmetry was noted in 32/200 subjects (16%). The anterior ethmoidal artery (AEA) canal was seen in 341/400 sides (85.2%). We found Keros type II was the most common type in our study. We also found grade I anterior ethmoidal artery as the most common variant and the dangerous grade III anterior ethmoidal artery was least common type found in this study, and there was a significant association of Keros type II with increasing anterior ethmoidal artery grading.

Severe unilateral refractory epistaxis arising from the septal branch of the anterior ethmoid artery.

KEY POINTS: The septal branch of the anterior ethmoid artery (sbAEA) is an underrecognized source of severe refractory epistaxis. Herein, we describe the presentation, predisposing factors, treatment strategies, and outcomes of a series of patients with this condition.

Supraorbital ethmoid cells (SOECs), anterior ethmoid artery notch and ethmoid roof relation in PNSCT.

OBJECTIVES: We investigated supraorbital ethmoid cell (SOEC) presence and types in paranasal sinus computed tomography (PNSCT). METHODS: The PNSCT images of 188 adult patients (93 males and 95 females) were evaluated as SOEC group (n = 87 sides), and non-SOEC group (n = 289 sides, control). In both groups, anterior ethmoid artery (AEA) notch-ethmoid roof distance and presence of AEA canal were evaluated. In the SOEC group, SOEC types (type 1 to 3) and SOEC angle are also examined. RESULTS: SOEC was detected in 87 sides (23.13 %). SOEC type 2 was the most detected type (71.3 %). AEA notch-ethmoid roof distance of the SOEC group was significantly higher than those in the non-SOEC group. AEA notch-ethmoid roof distance of the SOEC Type 3 group was significantly higher than SOEC Type 2 group. AEA notch-ethmoid roof distance was 3.74 ± 1.81 mm in the SOEC group and 0.68 ± 1.16 mm in the non-SOEC group. When SOEC types were considered, this distance was 5.29 ± 2.66 mm in type 3, 3.35 ± 1.35 mm in type 2 and 3.48 ± 0.92 mm in type 1. In higher SOEC types, SOEC angle; and AEA notch-ethmoid roof distance increased. CONCLUSION: In more pneumatized SOEC presence, SOEC angle increase, and AEA notch-ethmoid roof distance increases, AEA runs inferiorly in the ethmoid cells and freely below the skull base; and is more susceptible to injury. The surgeons should be more careful not to damage AEA in the FESS when detecting well-pneumatized SOECs (SOEC Type 3).

Anatomical Factors that Can Predict the Structure of Lamina Papyracea for Endoscopic Sinus Surgery.

OBJECTIVES: This study investigated morphological variations of lamina papyracea, the structure that should be carefully considered when opening posterior ethmoid sinus during endoscopic sinus surgery, to avoid injury. STUDY DESIGN: This study employed axial, coronal, and sagittal computed tomography. METHODS: Using computed tomography images of 228 face-sides, various anatomical parameters were determined: distances of the anterior and posterior ethmoid arteries from the skull base, and from the third lamella; changes in the angles of the lamina papyracea at the anterior and posterior ethmoid sinuses; and presence or absence of supraorbital ethmoid cell (SECs), Onodi cell, and Haller cell. The relationship between the distances which indicate the point of maximum projection by the lamina papyracea among third lamina and posterior ethmoid artery into the posterior ethmoid sinus and these anatomical factors were analyzed statistically. RESULTS: The projection distance of lamina papyracea into the posterior ethmoid sinus was -2.6 mm to 3.4 mm, and in 41.2% of cases, projection in the direction of the nasal cavity was greater than that of the lamina papyracea at the anterior ethmoid sinus. This distance increased with increasing distance of the maximum projection point from the skull base and increasing floating distances of the anterior and posterior ethmoid arteries. The number of subjects with large projection distances was increased among those with floating posterior ethmoid arteries. In addition, subjects with SECs had significantly greater projection distances. CONCLUSIONS: Particular care should be taken to avoid injury to the lamina papyracea when opening the posterior ethmoid sinus in subjects with floating anterior or posterior ethmoid arteries, and/or SEC. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E19-E25, 2021.

Pediatric Septal Perforation Repair With the Endoscopic Anterior Ethmoid Artery Flap.

Pediatric nasal septal perforations can lead to crusting, obstruction, whistling, and recurrent epistaxis. Current approaches for pediatric nasal septal repair center on combination endonasal and external approaches. Herein we describe the successful utilization of a purely endoscopic anterior ethmoid artery flap, an established technique in adults, for nasal septal perforation repair in 3 children aged 12 to 13 years who presented with septal perforations ranging in size from 6 to 12 mm. Successful closure was achieved with an endoscopic anterior ethmoid artery flap, with all patients achieving complete closure and symptom resolution. Children with nasal septal defects are typically treated with temporizing measures until early adulthood, when definitive open repair may be performed. Our initial experience with the anterior ethmoid artery flap technique suggests that this surgery may be easily performed in children as young as 12 years, without the use of previously described adjunctive procedures such as turbinate translocation.

Estimation of the ethmoid roof depth and length of lateral lamella of the cribriform plate, upper attachment of the uncinate process and anterior ethmoid artery in multiplanar reconstructions of Computed Tomography.

The aim is to assess the relationship of Anterior Ethmoid Artery with the Upper Attachment of the Uncinate Process and their relation with the Lateral Lamella of the Cribriform Plate in multiplanar reconstructions (i.e. coronal, axial and sagittal) of Computed Tomography. We measured the depth of the olfactory fossa, the length of the LLCP and determined the most superior attachment of the uncinate process, which designates boundaries of the frontal recess anteriorly, laterally and medially [20,22]. METHODS: All CT examinations were performed using the 320-detector Aquilion ONE CT Scanner (Canon Medical Systems, Otawara, Japan). Axial, coronal,sagittal reconstructions were performed by using dedicated workstation software (Vitrea Enterprice Siute, Version 6.7; Vital Images, Minnetonka USA). The Statistica 13 software was used for the analysis, results were considered statistically significant at the level of p<0,05. RESULTS: The most frequent types of Uncinate Process according to Landsberg- Friedman criteria in group of mens are: type I-30,77%,type II-30,77%, type III-26,92%, type VI-7,69%, type V-3,85%, type IV-0% respectively. In women's group: type III-44,12%,type II-32,35%, type I-8,82%,type V-8,82%, type IV-5,88%, type VI-0%. The median LLCP length in the anterior-posterior dimension measures 13 mm i. e. Yenigun type II on the both sides. The median value of depth in the superior-inferior dimension of the LLCP in the ethmoid roof is 5 mm i.e. Keros type II on both sides. The mean distance between Anterior Ethmoid Artery and Upper Attachment of the Uncinate Process measures approximately 9,73 mm and 9,16 mm on the right and left side respectively. CONCLUSIONS: The assessment of the AEA, UAUP and configuration of the anterior skull base on CT multiplanar reconstructions contribute to optimazing the results of frontal sinus surgery.

Angiographic study of the transdural collaterals at the anterior cranial fossa in patients with Moyamoya disease.

Unlike its parietal, temporal, and occipital counterparts, the frontal lobe has a broad basal surface directly facing the anterior cranial fossa dura mater which could permit establishment of transdural collaterals (TDCs) with the frontal lobe. Studies on the TDCs from the anterior cranial fossa in moyamoya disease (MMD) are scarce and inadequately investigated. A retrospective study of 100 hemispheres in 50 patients who were diagnosed with MMD by catheter angiography between January 2015 and June 2019 was performed in our institution. TDCs through the anterior ethmoid artery (AEA) or posterior ethmoid artery (PEA) were divided into 3 types respectively based on their respective angioarchitecture. Furthermore, we also studied TDCs to the temporal, parietal, and occipital lobes and collaterals from the posterior circulation to the territory of the anterior cerebral artery. TDCs through the AEA and PEA were identified in 89 (89/100, 89%) and 73 (73/100, 73%) of the hemispheres. The vascularization state of the frontal lobe was good in 89 (89/100, 89%) hemispheres. Rete mirabile and TDCs through the PEA were statistically different among patients with different Suzuki stages. No statistical difference was noted in TDCs through the AEA, frontal TDCs from other sources, and the vascularization state of the frontal lobe with regard to different Suzuki stages. TDCs through the AEA and PEA at the anterior cranial fossa play a very important role in compensating the ischemic frontal lobe. The frontal lobe could be well compensated in most of the patients with TDCs at the anterior cranial fossa.

Reliability of the supraorbital ethmoid cell vs Keros classification in predicting the course of the anterior ethmoid artery.

BACKGROUND: We previously showed that the supraorbital ethmoid cell (SOEC) is a reliable landmark for identifying the anterior ethmoid artery (AEA). Recent data have suggested that Keros classification is also a dependable predictor. We aim to characterize the location of the AEA and its relation to the skull base in patients with and without SOEC using the Keros classification. METHODS: Retrospective radiographic evaluation of computed tomography (CT) scans of 76 patients (40 with SOEC, 36 without) was conducted. Distance of AEA from skull base and prevalence of AEA outside of the skull base were measured on each side and compared between groups using the 2-sample t test and χ2 test, respectively. Subgroup analysis was carried out based on the Keros classification. RESULTS: Mean distance of AEA from the skull base was 1.32 ± 1.5 mm in patients with SOEC and 0.47 ± 1.08 mm in those without (p < 0.001). Prevalence of AEA outside of the skull base was 53.8% in those with SOEC and 18.1% in those without (p < 0.001). Comparing patients with SOEC to those without, AEA was found below the skull base in 30% vs 0% of cases with Keros type 1 (p = 0.45), 58% vs 14.5% with Keros type 2 (p < 0.001), and 60% vs 50% with Keros type 3 (p = 0.72). CONCLUSION: The presence of SOEC is associated with a higher prevalence of the AEA coursing below the level of the skull base in all Keros types, thus placing the artery at greater risk for injury. Careful surgical planning is needed to avoid potential orbital complications.

Ethmoid pneumatization and a large frontal-orbital-ethmoid mucocele.

Frontal-orbital-ethmoid mucocele is a slow-growing retention cyst of the fronto-ethmoid complex secondary to blockage of the sinus ostia. It may produce significant disfigurement of the periorbital region necessitating surgical intervention. Prior to surgery, it is imperative to study the mucocele's extent through the variable patterns of ethmoid pneumatization as evident from clinical, imaging (computed tomogram) and endoscopic evaluation. This is illustrated in a case study of a 41-year-old woman presenting with fullness below the right eyebrow, progressive proptosis, and gaze restriction. The provisional diagnosis of frontal-orbital-ethmoid muco(pyo)cele was confirmed at endoscopic surgery, when it was drained and marsupialized through ethmoidectomy and frontal sinusotomy. Understanding the relationship of an enlarging mucocele with the inconsistent pattern of ethmoid pneumatization is the primary determinant for an uneventful and complete surgery, and to minimize recurrence. The gradually expanding mucocele occupies the path of least resistance and encroaches into the available spaces of ethmoid labyrinth, distorting key anatomic landmarks and making surgical intervention potentially challenging. Thus, preoperative imaging corroborated with naso-endoscopy is of paramount importance to trace the lesion along ethmoid pneumatization, and determine the relative positions of structures vulnerable to surgery. This often requires a comparative study of the contralateral side because the mucocele generally obscures the pneumatization pattern and vital landmarks on its side. The present imaging tutorial studies the extent of a large frontal-orbital-ethmoid mucocele through interpretation of multiplanar computed tomography cuts, keeping in mind the unpredictable nature of its expansion as a function of the highly individualistic ethmoid pneumatization.

Nasal branch of the anterior ethmoid artery: a consistent landmark for a midline approach to the frontal sinus.

BACKGROUND: Frontal sinusotomy can be challenging when significant scarring or distorted anatomy is present. Identifying a reliable anatomic structure, when traditional landmarks or navigation are absent, may assist the surgeon in revision and complicated frontal sinusotomies via a midline approach. We aimed to characterize the anatomic relationship of the nasal branch of the anterior ethmoid artery (NBAEA) to the frontal infundibulum, specifically the first olfactory fili, posterior frontal infundibulum, and anterior cribriform plate. METHODS: Dissection of the NBAEA was carried out in 11 cadaveric heads, resulting in a total of 21 dissections (1 aplastic frontal). Mean with standard deviation and a range were established for 7 relative measurements. RESULTS: The total length of NBAEA cleft when present (mean 2.43 mm), the anterior edge of NBAEA cleft to anterior infundibulum coronal plane (mean 1.71 mm), the posterior edge of NBAEA cleft to posterior infundibulum coronal plane (mean 3.33 mm), the posterior edge of NBAEA cleft to 1st olfactory fili (mean 2.86 mm), and the first olfactory fili to posterior infundibulum coronal plane (mean 0.48 mm) were consistent measurements supporting the use of the NBAEA as a consistent anatomical landmark for the correct surgical coronal trajectory into the midline frontal sinus. CONCLUSION: The NBAEA is a consistent anatomic landmark with minimal intercadaveric and intracadaveric variation. It can be used reliably as a "sentinel artery" notifying the surgeon when one is approaching the first olfactory fili, to determine the correct trajectory into the midline frontal sinus.

Prevalence of supraorbital ethmoid air cells among Filipinos

Objective@#This study aims to determine the prevalence of supraorbital ethmoidal cells (SOEC) among Filipinos in a single tertiary government institution. @*Methods@#Study Design: Retrospective review of CT scan images. Setting: Single Tertiary Institution. Patients: 123 patients aged 13-years-old and above.@*Results@#A total of 474 CT scans (60 PNS and 414 Craniofacial) performed during the study period were considered, with 55 excluded for age < 13, and 296 excluded for craniofacial fractures. None had congenital craniofacial deformities. Eighty-five of 123 CT scans (69.11%) or 147 of 246 sides (59.76%) demonstrated supraorbital ethmoidal cells. There were 62 (72.94%) males and 23 (27.06%) females, ages ranging from 13 to 83 (mean age between male and female was 39.53 and 43.57). The scans showed 62 (50.41%) patients with bilateral and 23 (18.70%) with unilateral SOEC. Twenty-two (25.9%) patients were identified with chronic rhinosinusitis and two of whom were considered to have maxillary sinus mass. Two out of 5 patients with SOEC presented with aplastic/hypoplastic frontal sinus.@*Conclusion@#Our study suggests that Filipinos may have a higher prevalence rate of SOEC than their Chinese, Japanese and Korean counterparts and bilateral SOEC are more predominant than unilateral SOEC.

Analysis of the Relationship between the Location of the Anterior Ethmoid Artery and Keros Classification.

Objective We sought to identify a relationship between skull base height and anterior ethmoid artery (AEA) anatomy. Study Design Retrospective radiologic chart review. Setting University of Arkansas for Medical Sciences. Subjects Patients seen in a tertiary rhinology clinic between September 2014 and October 2015. Methods Review of 101 maxillofacial computed tomography scans with institutional review board approval. Skull base height and AEA locations were measured on each side. Prevalence of the AEA outside of the skull base and distance of the AEA from skull base were calculated and compared with Keros classification using χ2 testing. Comparisons of skull base height between sexes and age and distance between skull base and the AEA among Keros 2 and Keros 3 patients were made using an unpaired, 2-tailed t test. Results The AEA was located below the skull base in 25.7% of cases and more often in Keros type 3 (55%) than in Keros type 2 (29.5%) or Keros type 1 (0%) ( P < .05). Male patients were significantly more likely to have a greater average skull base height (5.25 vs 4.28 mm) and to have AEAs below the skull base (38.4% vs 14.8%). In addition, the distance of the AEA from the skull base was significantly higher in Keros type 3 patients compared with Keros type 2 patients (4.55 vs 3.42 mm, P = .001). Conclusions Variations in the AEA pathway occur more in male patients and those with higher Keros classifications. The distance between the variant AEA and the skull base increases with higher Keros classification. Keros classification can yield insight to the location of the AEA.

Classification of suprabullar pneumatization according to the skull base attachment of the second lamella.

The skull base attachment of the second lamella and suprabullar pneumatization are likely to be consistent landmarks if they are systematically classified. This study aimed to classify the pneumatization pattern according to the second lamella skull base attachment. A total of 202 computed tomography sides of 101 patients who underwent endoscopic sinus surgery were studied. Suprabullar pneumatization was defined as air cells present above the ethmoid bulla between the second and third lamellae. Its pattern was classified according to the air cell number and location as in the frontal cell classification. Type 0 suprabullar pneumatization was defined as no air cells between the ethmoid bulla and skull base; type 1, as a single suprabullar cell; and type 2, as multiple suprabullar cells above the ethmoid bulla. In type 3 pneumatization, the second lamella extended into the frontal sinus forming a frontal bullar cell. Type 2 was the most prevalent (40.1 %), followed by types 1, 3, and 0 (24.3, 23.3, and 12.4 %, respectively). The distance between the second lamella and anterior ethmoid artery was 8.93, 8.30, 8.50, and 11.25 mm in types 0, 1, 2, and 3 pneumatization, respectively. No patients had intraoperative injuries in the anterior ethmoid artery or lateral lamella. The second lamella skull base attachment and suprabullar pneumatization pattern could be systematically classified and be a consistent landmark to identify the frontal sinus opening.

Surgical Management of Severe Epistaxis.

Many patients with severe epistaxis benefit from endoscopic intervention for control of bleeding. Critical maneuvers to improve endoscopic visualization during surgery include head-of-bed elevation, application of topical vasoconstrictors, and local injection of vasonstrictors. Controlled, hypotensive anesthesia may also decrease intraoperative blood loss and improve visualization during surgery. Intractable posterior epistaxis can be controlled with high rates of success with endoscopic sphenopalatine artery ligation. Although less common, intractable anterior epistaxis may be controlled by anterior ethmoid artery ligation once this artery is identified as the primary source. Less common sources of severe epistaxis are also discussed in this article.

Hemorrhagic Complications of Endoscopic Sinus Surgery.

Major complications during endoscopic sinus surgery are rare and occur in 0.36% to 3.1% of patients. Postoperative hemorrhage accounts for 23% to 39% of complications. Despite being rare, major hemorrhage can be serious for the patient. This article discusses hemorrhagic complications during and following endoscopic sinus surgery, focusing on a review of the surgical anatomy, common pitfalls to avoid, preventative measures, and management of certain catastrophic complications for which preparedness can mean the difference between life and death.

Frontal sinus septations predict the presence of supraorbital ethmoid cells.

OBJECTIVES/HYPOTHESIS: This study is undertaken to determine if the presence or absence of multiseptated frontal sinuses is associated with the presence or absence of supraorbital ethmoid cells (SOECs). STUDY DESIGN: Analysis of prospectively collected data. METHODS: Sixty consecutive patients with chronic rhinosinusitis were identified from a prospectively collected database at a tertiary-referral institution as having full-sinus computed tomography (CT) scans. Preoperative or initial CT scans of the sinuses were reviewed, specifically identifying the presence or absence of supraorbital ethmoid air cells (SOECS) and frontal sinus multiseptated sections on coronal imaging. Statistical analysis was performed using the chi-squared test to evaluate any association between the two structural entities. RESULTS: Sixty total patients were identified, for a total of 120 sides. Of the 61 sides with frontal septations, 43 (70%) had SOECs present and 18 (30%) did not. Of the 59 sides without frontal sinus septations, 13 (22%) had SOECs present and 46 (78%) did not (chi squared = 28.3; P = 0.0000001). The difference in the presence of supraorbital ethmoid cells between whites and blacks is also statistically significant (chi squared = 4.23; P = 0.040). CONCLUSION: The presence of frontal sinus septations appears to be significantly associated with and predictive of the presence of supraorbital ethmoid cells. Thus, identifying frontal sinus septations on sinus CT is implicated with more complex anatomy of the frontal recess.

Evaluation of anterior ethmoidal artery by 320-slice CT angiography with comparison to three-dimensional spin digital subtraction angiography: initial experiences.

OBJECTIVE: To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference. MATERIALS AND METHODS: From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated. RESULTS: The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 ± 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 ± 0.01 mSv) (p < 0.001). CONCLUSION: 320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases.

Evaluation of Anterior Ethmoidal Artery by 320-Slice CT Angiography with Comparison to Three-Dimensional Spin Digital Subtraction Angiography: Initial Experiences

OBJECTIVE: To explore the usefulness of 320-slice CT angiography (CTA) for evaluating the course of the anterior ethmoidal artery (AEA) and its relationship with adjacent structures by using three-dimensional (3D) spin digital subtraction angiography (DSA) as standard reference. MATERIALS AND METHODS: From December 2008 to December 2010, 32 patients with cerebrovascular disease, who underwent both cranial 3D spin DSA and 320-slice CTA within a 30 day period from each other, were retrospectively reviewed. AEA course in ethmoid was analyzed in DSA and CTA. In addition, adjacent bony landmarks (bony notch in medial orbital wall, anterior ethmoidal canal, and anterior ethmoidal sulcus) were evaluated with CTA using the MPR technique oriented along the axial, coronal and oblique coronal planes in all patients. The dose length product (DLP) for CTA and the dose-area product (DAP) for 3D spin DSA were recorded. Effective dose (ED) was calculated. RESULTS: The entire course of the AEA was seen in all 32 cases (100%) with 3D spine DSA and in 29 of 32 cases (90.1%) with 320-slice CTA, with no significant difference (p = 0.24). In three cases where AEA was not visualized on 320-slice CTA, two were due to the dominant posterior ethmoidal artery, while the remaining case was due to diminutive AEA. On MPR images of 320-slice CT, a bony notch in the orbital medial walls was detected in all cases (100%, 64 of 64); anterior ethmoidal canal was seen in 28 of 64 cases (43.8%), and the anterior ethmoidal sulcus was seen in 63 of 64 cases (98.4%). The mean effective dose in CTA was 0.6 +/- 0.25 mSv, which was significantly lower than for 3D spin DSA (1.3 +/- 0.01 mSv) (p < 0.001). CONCLUSION: 320-slice CTA has a similar detection rate for AEA to that of 3D spin DSA; however, it is noninvasive, and may be preferentially used for the evaluation of AEA and its adjacent bony variations and pathologic changes in preoperative patients with paranasal sinus diseases.