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.

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.

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.

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.