Anterior Ethmoidal Artery Emerging Anterior to Bulla Ethmoidalis: An Abnormal Anatomical Variation in Waardenburg's Syndrome

Abstract

In endoscopic sinus surgery, the anterior ethmoidal artery (AEA) is usually identified as it traverses obliquely across the fovea ethmoidalis, posterior to the bulla ethmoidalis and anterior to or within the ground lamella's attachment to the skull base. Injury to the AEA may result in hemorrhage, retraction of the AEA into the orbit, and a retrobulbar hematoma. The resulting increase in intraorbital pressure may threaten vision. Waardenburg's syndrome (WS) is a rare congenital, autosomal dominantly inherited disorder, distinguished by characteristic facial features, pigmentation abnormalities, and profound, congenital, sensorineural hearing loss. We present a case of AEAs located anterior to the bulla ethmoidalis in a 36-year-old male with WS and chronic rhinosinusitis. The anatomic abnormality was not obvious on a preoperative computed tomography scan and was discovered intraoperatively when the left AEA was injured, resulting in a retrobulbar hematoma. The hematoma was immediately identified and decompressed endoscopically without lasting complications. The AEA on the right was identified intraoperatively and preserved. The characteristic craniofacial features in WS were probably associated with the abnormal vascular anatomy. Endoscopic sinus surgeons should be aware of these potential anatomic anomalies in patients with abnormal craniofacial development.

Study of Anthropometric Measurements of the Anterior Ethmoidal Artery using Three-dimensional Scanning on 300 Patients

“…12 When completely severed, however, the AEA may retract to the inside of the orbit and continue to bleed, resulting in retrobulbar hemorrhage. 6,13 The progression causes loss of visual acuity or even amaurosis if orbital decompression is not performed. 11 Lesion to the middle portion of the AEA, where it gets into the lateral lamella of the lamina cribrosa, may lead to CSF fistula.…”

“…11 Lesion to the middle portion of the AEA, where it gets into the lateral lamella of the lamina cribrosa, may lead to CSF fistula. 13 The AEA embolization is dangerous, because it can cause retrograde migration of particles to the ophthalmic artery with risk of blindness. 14 Several studies have developed techniques to facilitate AEA identification, either through CT scan analyses or cadaver dissection.…”

“…Many landmarks for distance have been tested, such as the anterior nasal spine, the axilla of the middle turbinate, the lacrimal crest, and the frontal recess. 2,4,6,8,13,15 The aim of this study was to analyze and compare the measurements from the AEA to the ethmoid bulla and to the frontal beak through facial CT scan, while identifying their intraindividual and interindividual variations.…”

WITHDRAWN: The utilization of paranasal sinus coronal tomography scans as a predictor for the anterior ethmoidal artery course.

“…Recognize the position and course of AEA through focused reading of CT scan of the patients is very crucial before surgery, As Wong et al described that the area of the AEA is fundamental and important for surgeon due to their worries regarding the possible complications (such as bleeding, CSF leak and, retrobulbar hematoma) that can occur if there is injury to the AEA or its surrounding area [7]. Moreover, many authors mentioned that AEA is a good anatomical landmark to locate the frontal recess, which aids in both frontal and ethmoid sinus surgery as well as for the localization the skull base in endonasal surgery [1,2,4].…”

“…Due to varying variable relations between the AEA and the ethmoid roof during its path through the nasal cavity from the medial orbital wall towards the olfactory fossa, the artery is at risk during surgical procedures [4,5]. Accordingly, identifying its course allows the surgeon during endoscopic procedures to avoid unwanted damage to it which may leads to intraorbital bleeding if the AEA retracted back to orbit due to injury at the lateral side of the artery ( proximal to the AEF) or can produce cerebrospinal uid leak if the damages occurs at the medial aspect of the artery [6,7].…”