Relation between anterior ethmoidal artery course on computed tomography and supraorbital ethmoid cell and Keros classification.

PURPOSE: The anterior ethmoidal artery (AEA) is an important risk area in endoscopic sinus surgery. This study aimed to evaluate the course of AEA according to the Keros classification and the presence of supraorbital ethmoid cell (SOEC) and to prevent possible complications by emphasizing the importance of preoperative paranasal computed tomography (CT) imaging. This approach will increase the effectiveness of endoscopic sinus surgery and improve patient safety. METHODS: The paranasal CT scan images of patients aged > 18 years between October 2020 and November 2021 from our center were retrospectively analyzed. The images were primarily evaluated in the coronal plane, and the sagittal and axial planes were utilized to evaluate variations in AEA regarding the skull base. Furthermore, the relation of AEA course with Keros classification and SOEC was evaluated. The study included 1000 patients aged 18-80 years (right and left, a total of 2000 samples). RESULTS: Grade 3 AEA was the most common regarding the skull base. Keros Type 2 was the most common classification. Overall, 48.7% patients had SOEC. The incidence of Grade 3 AEA was higher among patients with SOEC and a higher Keros classification compared with those without SOEC and a lower Keros classification. Furthermore, Keros Type 3 was the most associated with SOEC presence. CONCLUSION: Consistent with the literature, the probability of Grade 3 AEA in patients with high Keros classification and SOEC was significantly higher in our study. Therefore, we consider that preoperative imaging according to Keros classification and SOEC presence can predict AEA course and guide surgery.

"Boot-on-Donut" procedure for anterior and large septal perforation.

BACKGROUND: Surgical closure of large nasoseptal perforation (NSP) is challenging. The use of an extended anterior ethmoidal artery (eAEA) flap to reconstruct NSP may present with difficulties for NSPs which have their upper edge in a high position. METHOD: We propose adding a "donut-shape" flap from surrounding septal tissue to the eAEA flap. Thus, the inverted edges of this flap allow to cover the uppermost aspect of the NSP. A series of 18 patients with complete closure of NSPs was included. CONCLUSION: This novel "Boot-on-Donut" technique consisting of the eAEA flap (Boot) and inverted edges (Donut) is a feasible procedure that allows to reconstruct large NSP located superiorly.

Examination of ethmoidal roof regarding Keros and Yenigun classifications in a Turkish population: a computerized tomography study.

PURPOSE: Understanding ethmoid roof morphology is crucial to prevent complications in endoscopic sinus surgery. This study aimed to evaluate the morphological properties of the ethmoidal roof regarding gender and age differences using Keros and Yenigun classifications on high-resolution computed tomography images. METHODS: We retrospectively analyzed 891 high-resolution computed tomography paranasal sinus study images and measured the depth of the cribriform plate in coronal sections and the anterior-posterior length in axial planes. The study retrospectively examined CT images of paranasal sinuses of patients living in the eastern Anatolian region of Turkey. RESULTS: In both Keros and Yenigun Classifications, the most common class was type 2, and the least common class was type 3. According to Keros et al.'s method, no significant difference was observed between men and women (p = 0.698). However, according to Yenigun et al., the average values of women in terms of the anterior-posterior distance of the ethmoid roof were significantly higher than men (p = 0.001). When examined according to age, a very low, negative correlation was revealed regarding Keros and Yenigun classifications (p = 0.047 and p < 0.001 retrospectively). According to Keros and Yenigun's classification, there was no significant difference between the left and right sides (p = 0.488 and p = 0.919, respectively). CONCLUSION: The morphological properties of the ethmoidal roof have importance to be considered for preoperative planning. Studying larger patient groups and meta-analyses that gather various research results about this subject might help better understand the ethmoidal roof morphology among populations.

Radiological relationship of the ethmoid slit with the frontal sinus and the anterior ethmoidal artery and applications to the frontal sinus drillout.

PURPOSE: To compare two types of CT acquisition parameters: CT scan of the facial bone and CT scan of the sinuses, for studying the ethmoidal slit and its relationship with the frontal sinus and anterior ethmoidal artery. MATERIALS AND METHODS: Retrospective study of 145 scans of the sinuses and 79 of the facial bones performed between 2012 and 2016. On each scan, the visibility of the ethmoidal slits, their length, their distance from the ethmoidal artery, and their relationship with the anterior and posterior wall of the frontal sinus were studied. RESULTS: The ethmoidal slit was better visualized on CT scans of the facial bone (58.2%) than on those of the sinuses (43.1%) (p = 0.02). The distance between the anterior ethmoidal artery and the anterior part of the cribriform plate was 9.3 mm for CT scans of the facial bone and 8.4 mm for CT scans of the sinuses. The theoretical risk of damaging the glabellar soft tissue and that of damaging the meninges during a frontal sinusotomy was evaluated, respectively, at 9.6% and 26.1% for CT scans of the facial bone, and at 6.2% and 21.5% for sinus scans. CONCLUSIONS: CT scans of the facial bone are better than CT scans of the sinuses for identifying ethmoidal slits and their distance from the canal of the anterior ethmoidal artery. The identification of these elements is relevant for the surgeon during frontal sinus surgery and makes it possible to assess the risk of damaging the glabellar soft tissue or meninges. Performing a CT scan of the facial bone seems preferable to that of a CT scan of the sinuses in certain pathological situations, such as cerebrospinal rhinorrhea or revision surgeries of the frontal sinus.

Anatomical landmarks for localisation of the anterior ethmoidal artery: a combined radiological and cadaveric (endoscopic) study.

PURPOSE: The anterior ethmoidal artery is a major surgical landmark that is susceptible to iatrogenic injury during surgery of the anterior ethmoidal sinus, frontal sinus, and skull base. The present study aimed to define the location of the anterior ethmoidal artery in relation to specific anatomical landmarks using radiological imaging and endoscopic dissection. METHODS: Eighty-six anterior ethmoidal arteries were assessed using computed tomography scans (bilateral analyses) and forty anterior ethmoidal arteries were assessed using cadaveric specimens (bilateral analyses). The skull base, anterior nasal spine, anterior axilla of the middle turbinate, and nasal axilla were morphometrically analysed to determine their reliability as anterior ethmoidal artery landmarks. RESULTS: Distances to the skull base, anterior nasal spine, and nasal axilla displayed statistically significant differences between sexes and sides (p < 0.05). All landmarks demonstrated excellent reliability as anatomical landmarks for the localisation of the anterior ethmoidal artery, radiologically and endoscopically (ICC values ranged from 0.94 to 0.99). CONCLUSION: The middle turbinate axilla was the most reliable landmark, due to the lack of statistically significant differences according to sex and laterality, and the high inter-rater agreement between measurements. Anatomical knowledge of variations and relationships observed in the present study can be applied to surgeries of the anterior ethmoidal sinus, frontal sinus, and skull base to improve localisation of the anterior ethmoidal artery, preoperatively and intraoperatively, and avoid iatrogenic injury of the vessel.

Position of the anterior ethmoidal foramen and trauma to the cranial base during transconjunctival medial orbital decompression: a systematic literature review.

PURPOSE: To review the literature on the location of the anterior ethmoidal foramen (AEF) and trauma during transconjunctival medial wall decompression. METHODS: A comprehensive literature search was conducted using the PubMed, Embase, and Scopus databases, combining the terms "olfactory fossa" and "fovea ethmoidalis" with "trauma," "cerebrospinal fluid leak," "pneumocephalus," "orbital decompression," and "anterior ethmoidal artery" (AEA). All cases of cranial base trauma during medial orbital decompression and the anatomical studies on the location of the AEF and the course of the AEA were reviewed. RESULTS: Ninety-four articles were identified, of which 37 were related to the AEF, 41 reported the course of the AEA, and 16 to reported cases of cranial base trauma. Out of these cases, 10 were related to transconjunctival medial orbital decompression, affecting 11 patients. Most AEFs are situated at the frontoethmoidal suture, but up to 38.15% of AEFs are located above the suture on the frontal bone. Most AEFs are adjacent to the roof of the ethmoidal sinus. The distance of the AEF to the cranial base increases in the presence of supraorbital ethmoidal cells (SOEC). CONCLUSIONS: The position of the AEF is variable and should not be considered a safe landmark for all patients.

Applications of Co2 laser in endoscopic surgery for sinonasal neoplasms.

OBJECTIVE: The aim of the study is to assess safety, effectiveness, and potential advantages of CO2 fiber laser during endoscopic endonasal surgery for the resection of sinonasal neoplasms. We present text, images, and videos to show our experience with this new device recently introduced in endoscopic endonasal surgery and as a potential tool for educational purpose. METHODS: Six patients affected by benign or malignant sinonasal tumors who underwent endoscopic resection between January and May 2021 were enrolled in the study. Surgical approach was conducted via standardized centripetal endonasal technique. During the surgery we evaluated instrument ergonomics, quality in section on both healthy tissue and tumor, coagulation, and bleeding control from major vessels. RESULTS: In our experience, CO2 fiber laser has proved to have good ergonomics, as well as to be a safe and effective tool for the resection of both neoplastic and healthy tissues. Cauterization was efficient only in vessels with average diameter lower than 1 cm. Prolonged procedural time, costs, and necessity of learning-curve and expertise are possible drawbacks. CONCLUSION: Co2-fiber laser is an effective tool which can aid the surgeon during endoscopic endonasal approach to sinonasal neoplasms.

Usefulness of computed tomography in predicting ethmoidal arterial bleeding in refractory epistaxis.

PURPOSE: Epistaxis that is refractory to conservative management can be treated with endoscopic sphenopalatine artery ligation (ESPAL). Although rare, ethmoidal artery (EA) bleeding can be a cause of rebleeding after successful ESPAL. EA bleeding is diagnosed by angiography and can also be identified during surgical exploration. However, since the angiographic embolization of the EA is contraindicated, surgical hemostasis is mandatory. This study investigated whether paranasal sinus (PNS) CT could provide information for predicting EA bleeding without angiography in patients with refractory epistaxis requiring ESPAL. METHODS: Forty-seven patients, who were surgically treated [with ESPAL or EA ligation (EAL)] for refractory epistaxis from March 2010 to June 2019, were retrospectively analyzed. A positive PNS CT finding for EA bleeding was defined as the presence of soft tissue densities having continuity with the EA pathway, accompanied by a partially deficient surrounding bony canal. These findings as well as soft tissue densities in each paranasal sinus were compared between the ESPAL and EAL groups. RESULTS: All patients in the EAL group had positive CT findings of EA bleeding, compared to only 12.2% in the ESPAL group (P < 0.001). The rate of soft tissue densities within the frontal and sphenoid sinuses were noted in 26.8% and 17.1% of patients in the ESPAL group, compared to 83.3% and 83.3% of patients in the EAL group (P = 0.013 and P = 0.003, respectively). CONCLUSION: PNS CT might be useful for predicting EA bleeding in patients with refractory epistaxis requiring surgical hemostasis.

Anatomical variations of anterior ethmoidal artery at the ethmoidal roof and anterior skull base in Asians.

PURPOSE: The variations of the anterior ethmoidal artery (AEA) in different populations should be recognized by surgeons to prevent unwarranted complications during surgery. The aim of this study was to assess the anatomical variations of AEA in Asian population. METHODS: A cross-sectional study of 252 AEA identified by computed tomography (CT) of the paranasal sinuses. The multiplanar CT images were acquired from SOMATOM® Definition AS+ and reconstructed to axial, coronal and sagittal view at 1 mm slice thickness. RESULTS: 42.5% of AEA was within skull base (grade I), 20.2% at skull base (grade II) and 37.3% coursed freely below skull base (grade III). The prevalence of supraorbital ethmoid cell (SOEC) and suprabullar cell (SBC) was 29.8% and 48.0%. The position of AEA at skull base has significant association with SOEC (p < 0.001), but not with SBC (p = 0.268). Type I Keros was 42.1% and Type 11 Keros was 57.9%. When lateral lamella's height is longer, the probability increases for AEA to course freely within the ethmoid sinus (p = 0.016). The mean distance of AEA from skull base was 1.93 ± 2.03 mm, orbital floor 21.91 ± 2.47 mm and nasal floor 49.01 ± 3.53 mm. CONCLUSIONS: The position of AEA at skull base depends on the presence of SOEC and length of lateral lamella, but not with SBC. When compared to European population, the mean distance between AEA and nasal floor is shorter in Asians.

Anatomical variations of the ethmoidal roof: differences between men and women.

AIM: During the paranasal sinuses surgery different complications may occur, both vascular and bony. The objective of the present study was to evaluate the ethmoidal roof configuration through the Keros and Yenigun classifications, analyzing results stratified by gender and side. MATERIALS AND METHODS: We retrospectively analyzed 120 high-resolution computed tomography paranasal sinus study images and measured the depth of the cribriform plate in a coronal view and the anterior-posterior length in a cross section. RESULTS: The Keros Type II was the most frequent and no statistically significant difference was found when comparing by gender. Yenigun type I was more prevalent, and a statistically significant difference was found between men and women in types I and II (p = 0.010 and p = 0.049, respectively). Statistical difference was observed in anterior-posterior means in the comparison between both classifications. In both, right and left side for men (p = 0.003 and p = 0.05) and women (p = 0.029 and p = 0.039). CONCLUSION: We demonstrate the morphological variability that exists in this region. Gender differences that must be considered by the surgeon to avoid complications. Further studies are needed to evaluate the value of these findings when predicting surgical complications. A CT before PNS surgery is already widely accepted.

Septal branches of the anterior ethmoidal artery: anatomical considerations and clinical implications in the management of refractory epistaxis.

PURPOSE: Epistaxis is a commonly presenting complaint. In severe cases, nosebleeds may occur despite antero-posterior nasal packing and often in the absence of identifiable sources of bleeding. In such cases, epistaxis may occur from septal branches of the anterior ethmoidal artery (sbAEA). The purposes of this study are to highlight the clinical role of the sbAEA in different fields of endoscopic endonasal surgery and to evaluate the efficacy and safety of their selective endoscopic endonasal ligation in the management of refractory epistaxis. METHODS: A retrospective review was performed of all patients presenting with epistaxis who underwent endoscopic endonasal coagulation of sbAEA in three Italian tertiary-care referral centers between October 2010 and October 2017. RESULTS: A total of 30 patients met the inclusion criteria. Sixteen patients had never experienced nosebleeds before, while 14 patients recalled previous epistaxes. Seventeen patients were treated under local anesthetic, while 13 required general anesthesia. No intra- or post-operative complications were observed and none of the patients received nasal packing after the procedure. In all cases the coagulation was effective in controlling the bleeding, with only two relapses in the series (2/30, 6.7%). CONCLUSIONS: The sbAEA are of great interest in endoscopic endonasal surgery, both as surgical landmarks and as feeding vessels for a variety of pedicled nasal flaps. What is more, they can be crucial for the management of refractory epistaxis. Their selective endoscopic coagulation represents an effective and safe procedure in cases of difficult-to-control epistaxis from the upper nasal fossa, with several advantages over nasal packing.

A study of the anterior ethmoidal artery and a new classification of the ethmoid roof (Yenigun classification).

Aims of this study are to analyze the association of the anterior ethmoidal artery's (AEA) visualization with variations in its adjacent structures in coronal, axial, and sagittal CT images, to assess its relation with the ethmoid roof, and, based on this relation, to introduce a new classification for the ethmoid roof. A retrospective, cross-sectional study was performed in a tertiary referral center. In this retrospective, cross-sectional study, the coronal, axial, and sagittal CTs of 184 patients have been surveyed and the AEA canal, the ethmoid roof, and their relations with surrounding structures have been assessed. The Keros classification used to measure the depth of the lateral lamella of the cribriform plate (LLCP) in the ethmoid roof has been modified to include anterior-posterior length of the LLCP. It was shown that the visualization of the AEA canal increases in a statistically significant manner with an increase in the superior-inferior depth and the anterior-posterior length of the LLCP bilaterally. In the presence of supraorbital pneumatization, AEA visualization was shown to increase bilaterally significantly. This study demonstrated a positive correlation between the AEA canal, the LLCP superior-inferior depth, and the anterior-posterior length. It was shown that with the increased depth and length of the LLCP and in the presence of supraorbital pneumatization, the visualization of the artery and hence the injury risks are increased. The LLCP anterior-posterior length is as clinically relevant as is its depth, and a radiologic classification has been defined according to the anterior-posterior length of the LLCP.

Three-dimensional evaluation of the danger zone of ethmoidal foramens on the frontoethmoidal suture line on the medial orbital wall.

INTRODUCTION: It is clear that the importance of the ethmoidal foramen (EF) is based on its vascular contents. The frontoethmoidal suture (FS) line is recommended as more reliable navigational landmark for identifying the EF. MATERIALS AND METHODS: The vertical orientation between the EF and the FS line was studied in 188 orbits using a computer software program. RESULTS: 146 anterior EFs (77.7 %) and 42 anterior EFs (22.3 %) were situated in the FS line as intrasutural and extrasutural, respectively. 146 posterior EFs (77.25 %) and 8 posterior EFs (4.25 %) were presented as intrasutural and extrasutural, respectively. Although accessory EFs were detected in 25.5 % specimen exhibited an extrasutural location. Majority of the EFs (1-4 EFs) were situated on the FS line. The mean distances from the FS and the anterior EF, the posterior EF and the accessory EF were measured as 2.1 ± 0.5, 2.0 ± 1.5 and 2.3 ± 1.2 mm, respectively. The range of the distances from the FS to the anterior EF, posterior EF and accessory EF were -1.2 to 3.32 , -1.02 to 5.76 and -1.1 to 3.65 mm, respectively. CONCLUSION: The ranges of EF changed within 1-6 mm. As the FS is not a single point, it is more suitable to make the incision 7 mm above the suture line. The data from this study to help the orbital surgeons explain and avoid unexpected hemorrhage during the orbital procedures such as posttraumatic orbital reconstruction, orbital tumor resections, anterior skull base reconstruction, and orbital decompression surgery.

The Upper Attachment of the Uncinate Process and Anterior Ethmoidal Artery.

OBJECTIVE: Variations in the upper attachment of the uncinate process (UP) are important because they can affect frontal sinus drainage and change the morphology. Functional endoscopic sinus surgery (FESS) is the primary technique used to treat chronic medically refractory rhinosinusitis. Uncinectomy is the basis of FESS technique to obtain the best possible result from surgery. The anterior ethmoidal artery (AEA) enters the nasal cavity through the orbital medial wall (lamina papyracea) may also be affected by the upper attachment of the UP. The aim of this study was to investigate a possible link between UP variations and the course of the AEA. MATERIALS AND METHODS: This retrospective, computed tomography (CT)-based, anatomic study was conducted on 200 healthy adults (100 females and 100 males) by screening bilateral paranasal sinus images. The upper attachment of the UP was classified in 6 types (1-6) based on the Liu classification. The AEA was divided into 4 types (A-D) based on location: anterior to the frontal sinus (A), between the frontal sinus and the middle nasal turbinate (B), and anterior to the posterior ethmoidal cells (C and D). All the CT images were evaluated simultaneously by 2 anatomists and 1 radiologist. RESULTS: Of the total cases (200 right and 200 left side), 48.8% were type 1 UP attachment, 11.0% type 2, 12% type 3, 9% type 4, 18% type 5, and 1.2% type 6. The AEAs were classified as 12.2% type A, 71.8% type B, 15.2% type C, and 0.8% type D. CONCLUSION: The course of the AEA through the nasal cavity was observed to shift anteriorly from the ethmoidal bulla to the frontal sinus in patients with UP attached to the lamina papyracea and middle turbinate. Remarkably, the AEA always coursed anterior from the middle nasal turbinate line.

The Complete Anatomy of the Anterior Ethmoidal Artery: A Meta-Analysis with Implications for Sinus and Skull Base Surgery.

Background: The anatomical characteristics of the anterior ethmoidal artery (AEA) exhibit a high degree of variability, especially regarding its topography. Methods: PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Google Scholar were searched to identify all studies that included information regarding the morphometric and topographical characteristics of the AEA. Results: Ultimately, a compilation of 38 studies meeting the predetermined criteria, and possessing comprehensive and pertinent data, were incorporated into the current meta-analysis. In the overall analysis, reports of the AEA being embedded within the skull base or at the level of the skull base producing a bony protrusion were found in 56.91% of cases (95% CI: 43.55-69.80%). The mean diameters of the AEA in the intraorbital and intracranial areas were 0.94 mm and 0.76 mm, respectively. Moreover, the artery coursed most commonly between the second and third lamellae, with a prevalence of 65.82% (95% CI: 55.39-75.56%). Conclusions: The AEA may be at a high risk of iatrogenic injury during various sinus and skull base surgeries, especially if the surgeon performing these procedures is unfamiliar with the vast number of variations this vessel may exhibit. The spatial relationship between this vessel and the skull base is especially variable, and understanding this variability goes hand in hand with intraoperative safety.

The tortuous course of the anterior ethmoidal artery in the orbit: A cadaveric study.

AIM: The study aimed to define the coursing pattern of the anterior ethmoidal artery (AEA) in the orbit to minimize complications during endoscopic interventions. MATERIALS AND METHODS: A total of ten formalin-fixed cadaveric halves were included in the study. Orbital regions were shown with a superior approach. The superior rectus and superior oblique muscles, as well as the connective tissue and vessels were removed to observe the path of the anterior ethmoidal artery. Measurements such as the width of the artery, the anterior-posterior length of the U formation, the length of the intraorbital part of the ophthalmic artery, and the distance of the AEA from its opthalmic origin to the anterior ethmoidal foramen were made. RESULTS: Ten of the AEAs originated from the ophthalmic artery. The AEA branches originated from the ophthalmic artery approximately 18.4 mm after the orbital artery entered the orbital, and the mean width of the AEAs was 0.82 mm. In seven of the total anterior ethmoidal arteries, they coursed in the intraethmoidal cavities below the cranial base. The mean distance from the origin of AEAs to the medial wall of the orbit was 4.9 mm. After leaving the ophthalmic artery, seven of the AEAs were coursing forward and turned back ('U' turn formation), which have proximately 1.5 mm in anteroposterior direction. CONCLUSION: The anterior ethmoidal artery is 0.8 mm wide, originates from the distal part of the ophthalmic artery, entering the orbit after a 1.5 mm U-turn.

A Consistent Endoscopic Landmark to Identify the Anterior Ethmoidal Artery.

OBJECTIVE: The anterior ethmoidal artery (AEA) is an important structure to identify during endoscopic sinus surgery. Although identification on imaging is easily taught, a consistent endoscopic landmark for the AEA, independent of anatomic ethmoid cell variation, is lacking, leaving many surgeons unclear about the exact location without dependence on navigation. Here, we describe a consistent endoscopic landmark, regardless of anatomical ethmoid variation. METHODS: We prospectively enrolled adult patients undergoing endoscopic surgery involving frontal and ethmoid sinuses in this observational study. The AEA landmark was defined simply as the septation or ridge one step back along the ethmoid skull base from the posterior table of the frontal sinus. The gold standard to calculate the sensitivity of our endoscopic landmark was an image-navigation system, registered to within 1.5 mm accuracy, locating the AEA within three planes. Both endoscopic and computerized tomography (CT) images of the pointer at the landmark were taken simultaneously. The concordance of endoscopic to navigation images was independently assessed by three blinded rhinologists. RESULTS: Forty patients were included in our study with 73 sides analyzed. Diagnoses included chronic rhinosinusitis without polyps (52.5%), with polyps (22.5%), recurrent acute sinusitis (15%), sinonasal tumors (7.5%), and odontogenic sinusitis (2.5%). The AEA was accurately identified using our endoscopic landmark in 97.3% of the cases (71/73). Of the two cases in which the AEA was not found within the landmark, the artery was located ≤1 mm posteriorly. CONCLUSION: We describe a consistent endoscopic landmark to identify the AEA, conserved across various clinical diagnoses and anatomic variations in sinus structure. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1096-1099, 2024.

Enhancing the coverage and rotation of anterior ethmoidal artery flap for septal perforation closure: Insights from a flap design study.

BACKGROUND AND OBJECTIVES: The anterior ethmoidal artery flap (AEA) is a pedicle endonasal flap frequently used to repair septal perforations (SP). The posterior incision is the most complex to perform. The primary objective was to determine the minimum height of the posterior incision (PI) of an AEA completely cover an anterior septal perforation. MATERIALS AND METHODS: A cadaveric specimen was sectioned in the sagittal plane and a SP of 1 cm was created anteriorly. The PI of the AEA flap was made progressively at a height of 10, 20, 30, and 40 mm. The complete closure of the SP and the angle of rotation (AR) of the flap were assessed. RESULTS: According to the length of the PI the following results were obtained: PI = 10 mm: The SP was covered partially, and the AR was 45º. PI = 20 mm: The SP was fully covered, and the AR was 63º. PI = 30 mm and 40 mm: The SP was fully covered with redundant tissue. This study shows that an anterior ethmoidal artery flap that includes the nasal floor and the inferior meatus mucosa combined with a posterior incision of 20 mm could result in adequate coverage of all margins of an anterior SP up to area 1a of the septum.

Accessory anterior ethmoidal nerve and artery: a cadaveric case report.

The anterior ethmoidal artery (AEA) is an important surgical landmark for procedures involving the anterior cranial fossa. Many variations in the location and branching pattern of the AEA have been reported throughout the literature. These anatomical variations are important for surgeons to be familiar with as injury to the AEA can lead to massive haemorrhage, orbital haematomas, and cerebrospinal fluid rhinorrhoea. Anatomical landmarks such as the ethmoidal foramen can be used to identify the location of the AEA; however, it is also important to consider that the foramen may have variable presentations. If there is ever difficulty with identification of the AEA, surgeons should pursue a high-resolution computed tomography to minimise the risk of surgical complications. In this report, we present a rare case of a variant accessory anterior ethmoidal artery and nerve, and variations in the ethmoidal foramen found during cadaveric dissection.

Analysis of the Correlation of the Lamina Papyracea-to-Midline Distance with the Location of Anterior Ethmoidal Artery and Keros Classification.

The aim of the study was to investigate the relations between anatomical structures that are susceptible to inadvertent injuries during the surgery using preoperative computed tomography (CT) scans. 153 CT scans were reviewed and the distance from the lamina papyracea (LP) to the midline and the distance of the anterior ethmoidal artery (AEA) to the skull base were measured bilaterally. Also, the depth of olfactory fossa was measured and categorized using the Keros classification. The measurements were analyzed to determine whether LP-to-midline distance was correlated with the distance between the AEA and the skull base and Keros classification. Additionally, correlation of Keros classification with the distance from the AEA to the skull base was investigated. In a total of 306 measurements, 26 (%8.49) were classified as Keros type I, 200 (65.35%) as Keros type II and 80 (25.14%) as Keros type III. Statistically, LP-to-midline distances on the right and left sides were significantly associated with the distance from the AEA to the skull base on the same side (R:p < 0.001, L:p = 0.01) and the Keros classification on the same side (R:p < 0.001, L:p = 0.004). Also, a significant association was found between the Keros classification and the distance from the AEA to the skull base (R:p < 0.001, L:p = 0.02). The locations of anatomical structures are defined in relation to each other during the development of maxillofacial bones. CT scans should be examined and anatomical structures and relations among them reviewed very carefully before ESS. Otherwise, some accidental injuries may arise during the surgery while trying to avoid complications. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-03931-x.