Internal Carotid Artery Canal Research Articles

Ruptured infectious ICA pseudoaneurysm into the sphenoid sinus after maxillofacial infection, successfully treated by selective embolization

Background: Intracranial infectious aneurysms are cerebral aneurysms caused by pathogen-induced inflammation undermining the arterial wall. We present a rare case of inflammatory pseudoaneurysm of cavernous internal carotid artery (ICA).Case Description: A 51-year-old female with a recent diagnosis of acute lymphoblastic leukemia developed maxillofacial infection with Pseudomonas and Acinetobacter after chemotherapy onset. Initial plain computed tomography (CT) revealed bony dehiscence of the left ICA canal, as well as bilateral protrusion of the vessel within the sphenoid sinus. Following infection spread into the left sphenoid sinus, she presented with episodes of intermittent epistaxis, without any profound vascular abnormalities on postcontrast CT. CT angiography that was performed 15 days later, due to refractory epistaxis, illustrated a large narrow necked irregular shape pseudoaneurysm of the left paraophthalmic ICA, extending into the ipsilateral sphenoid sinus. The aneurysm was completely occluded by selective embolization without parent or adjacent vessel sacrifice, documented on both intraoperative and follow-up angiogram, with no recurrence of epistaxis.Conclusion: Conclusively, ruptured internal carotid infectious aneurysms are rare but potentially fatal causes of epistaxis when extended into the sphenoid sinus. Selective coiling is feasible and can provide definitive treatment of these lesions.

NEUROIMAGING DATA OF THE STUDY OF THE CHIASMAL-SELLAR REGION STRUCTURES

NEUROIMAGING DATA OF THE STUDY OF THE CHIASMAL-SELLAR REGION STRUCTURES

Anatomical Variations of the Jugular Foramen Region in Patients with Pulsatile Tinnitus.

Objective Structural anomalies of the jugular foramen (JF) and adjacent structures may contribute to development of pulsatile tinnitus (PT). The goal of this study was to assess anatomical variants in the ipsilateral JF region in patients with PT and to explore possible predisposing factors for PT. Methods One hundred ninety-five patients with PT who underwent CT angiography and venography of the temporal bone were retrospectively analyzed. Anatomic variants including dominance of the ipsilateral JF, bony deficiency of the sigmoid sinus and internal carotid artery canal, high riding or dehiscent jugular bulb, dehiscence of the superior semicircular canal, tumors in the JF region, or cerebellopontine angle were assessed. Results Of 195 patients with PT, the prevalence of a dominant JF on the ipsilateral side of patients with PT was 67.2%. Furthermore, the dominant JF demonstrated a significant correlation with the presence of ipsilateral PT ( p < 0.001). No anatomical variants were present in 22 patients (11.3%), whereas in patients with structural variants, bony deficiency of the sigmoid sinus was most common (65.6%), followed by high riding (54.9%) or dehiscent jugular bulb (14.4%). Dehiscent internal carotid artery canal (3.1%) and superior semicircular canal (4.1%) were occasionally identified, while arteriovenous fistula, arterial aneurysm and tumors arising from the JF region or cerebellopontine angle were rarely encountered. Conclusion Structural abnormalities of the JF and adjacent structures may predispose to the development of PT. Knowledge of these anatomical variants in the JF region may help establish a clinical strategy for addressing PT.

Эффективность использования электромагнитной навигационной системы при хирургическом лечении новообразований височных костей

Purpose of the work: Increasing the efficiency of surgical treatment of patients with destructive pathology of the temporal bones through intraoperative use of an electromagnetic navigation system. The article showed the results of using the electromagnetic navigation system for surgical treatment of patients with temporal bone paraganglioma types B and C, facial neuromas and chronic otitis media with an unfavourable form in which radical mastoidectomy was previously performed. The features of preoperative preparation for surgical treatment of patients, surgical approaches (retrofacial, infratemporal, transcochlear) are described. For retrofacial access, the reference points were: a horizontal semicircular canal, the bone wall of the internal carotid artery and the jugular vein bulb. For infratemporal access, the reference points were the wall of the carotid artery, the jugular vein bulb and the internal auditory meatus. For transcochlear access, the carotid artery wall, jugular fossa and internal auditory meatus are considered landmarks. The use of the navigation system made it possible to navigate the complex anatomy during the operation and avoid injury to vital structures (internal carotid artery canal, jugular vein bulb, semicircular canals, facial nerve). The need to use navigation systems especially increases with anomalies in the development of the ear and when the boundaries between anatomical structures are destroyed by an inflammatory process or a neoplasm.

Endoscopic endonasal bony landmarks of vertical petrous internal carotid: anatomic study

BackgroundEndoscopic endonasal direct exposure or vascular control of basal internal carotid artery (ICA) is difficult among soft tissue of infratemporal fossa.ObjectiveThe aim of this work was to develop surgical instructional model for direct exposure of vertical petrous (Vp) ICA relatively dependent on bony fixed landmarks.Materials and methodsEndoscopic endonasal drilling of 14 sides of dry skull models was presented. Different bony landmarks and measurements of Vp ICA canal were obtained.ResultsEndoscopic endonasal transpterygoid approach was performed. The medial pterygoid process and base were drilled to expose the vidian canal and foramen rotundum. The lateral pterygoid process was drilled following the slope of skull base to medial and lateral ends of foramen oval (FO). The spine of the sphenoid was drilled to obscure the tensor tympani canal and the bony Eustachian tube (ET). The bony end of ET was identified lateral to FO. The Vp ICA was exposed retrogradely by drilling the tubal process of tympanic bone (bone between FO and bony ET) downward, backward, and medially toward carotid foramen, forming an acute angle with horizontal petrous (Hp) ICA. The carotid foramen lies medial to styloid process. Three processes are identified sequentially from endonasal perspective; spine of sphenoid, tubal process of tympanic bone, and vaginal process of tympanic bone enclosing the styloid process laterally. The mean length of Vp ICA canal was 12.93±2.23 mm, mean width of FO was 5.04± 0.8 mm, and distance between FO and bony ET was 6.68±1.42 mm, representing surgical width of Vp ICA ~10 mm. The surgical corridor was ~10mm wide and 15mm long.ConclusionEndoscopic endonasal systematic orientation of bony fixed landmarks of Vp ICA exposure is described. The proposed endonasal bony pathway relatively bypasses the muscular compartment of infratemporal fossa. This model can help to obtain vascular control of basal ICA and retrograde identification of parapharyngeal ICA.

Pneumatization patterns of onodi cell on multidetector computed tomography

Background: Onodi cell is the most common anatomical variant of posterior ethmoidal air cells. Pneumatization patterns of Onodi cell are important clinically due to its proximity to optic nerve and internal carotid artery canal. Multidetector computed tomography (MDCT) provides the best imaging modality for identification and pneumatization pattern of Onodi cell. Objectives: The present study is done to know the patterns of pneumatization of Onodi cell by 128 slice MDCT. Materials and Methods: This was a retrospective analysis of paranasal sinuses in 1080 cases by MDCT in adults. Axial images of paranasal sinuses were taken by 128 MDCT with further multiplanar reconstruction to identify Onodi cell and their pneumatization patterns. Statistical analysis was done using SPSS version 20, and 95% confidence interval (CI) values were calculated using a confidence Interval calculator for proportional values. Results: A total of 260 cases (24.07%, CI - 21.52%–26.62%) showed Onodi cell among the total 1080 cases included in this study. Males formed more cases than females with 62.69% and 37.31%, respectively, Type II was the most common pattern of pneumatization with 56.55% (CI - 50.12–62.18), followed by Type I with 41.53% (CI - 35.54–47.52) and Type III with 1.92% (CI - 0.25–3.59) of cases. Conclusion: Onodi cell is the most common anatomical variation of ethmoidal sinuses with higher prevalence among Asian populations. Their patterns of pneumatization are important clinically to avoid surgical damage to optic nerve and internal carotid artery canals. Onodi cell is better detected with MDCT and helpful for sinonasal surgeons for a better surgical outcome.

Pulsatile tinnitus associated with dehiscent internal carotid artery: An irremediable condition?

Dehiscent internal carotid artery (ICA) in the middle ear is a rare condition, with conservative treatment primarily recommended. We report the case of a 63-year-old patient referred to the Ear, Nose, and Throat (ENT) ward for unbearable pulsatile tinnitus. Otoscopy revealed a normal right tympanic membrane, with pulsatile tinnitus but without hearing impairment. Based on imaging studies, including computed tomography (CT) and magnetic resonance imaging (MRI) of the temporal bone, as well as Doppler ultrasound of the internal carotid artery and sigmoid sinus, the diagnosis of ICA canal dehiscence into the tympanic cavity was established, thus excluding the diagnosis of aberrant ICA.Following the patient's own request, we undertook surgical correction, with the technique used described in the report. Immediately postoperatively, the pulsatile tinnitus had disappeared, with no surgical complications noted. At the 9-month follow-up, otoscopy revealed a healthy right tympanic membrane and the patient reported no remaining symptoms.

Internal carotid arterial canal size and scaling in Euarchonta: Re-assessing implications for arterial patency and phylogenetic relationships in early fossil primates

Primate species typically differ from other mammals in having bony canals that enclose the branches of the internal carotid artery (ICA) as they pass through the middle ear. The presence and relative size of these canals varies among major primate clades. As a result, differences in the anatomy of the canals for the promontorial and stapedial branches of the ICA have been cited as evidence of either haplorhine or strepsirrhine affinities among otherwise enigmatic early fossil euprimates. Here we use micro X-ray computed tomography to compile the largest quantitative dataset on ICA canal sizes. The data suggest greater variation of the ICA canals within some groups than has been previously appreciated. For example, Lepilemur and Avahi differ from most other lemuriforms in having a larger promontorial canal than stapedial canal. Furthermore, various lemurids are intraspecifically variable in relative canal size, with the promontorial canal being larger than the stapedial canal in some individuals but not others. In species where the promontorial artery supplies the brain with blood, the size of the promontorial canal is significantly correlated with endocranial volume (ECV). Among species with alternate routes of encephalic blood supply, the promontorial canal is highly reduced relative to ECV, and correlated with both ECV and cranium size. Ancestral state reconstructions incorporating data from fossils suggest that the last common ancestor of living primates had promontorial and stapedial canals that were similar to each other in size and large relative to ECV. We conclude that the plesiomorphic condition for crown primates is to have a patent promontorial artery supplying the brain and a patent stapedial artery for various non-encephalic structures. This inferred ancestral condition is exhibited by treeshrews and most early fossil euprimates, while extant primates exhibit reduction in one canal or another. The only early fossils deviating from this plesiomorphic condition are Adapis parisiensis with a reduced promontorial canal, and Rooneyia and Mahgarita with reduced stapedial canals.

Accuracy of computer-aided geometric three-dimensional reconstruction of the human petrous bone based on serial unstained celloidin sections.

The aim of this study was to present a comprehensive three-dimensional (3D) morphology of the petrous bone with computer image-processing technology, which could be beneficial for the teaching of anatomy and for surgical procedures. The unstained celloidin sections of human temporal bone were digitized with high resolution and quality, and then processed with Amira® software to include alignment, segmentation and reconstruction. The integral structure of the human inner ear was presented with computer modeling, including the petrous bone, bone labyrinth, internal carotid artery canal, internal jugular vein canal, sigmoid sinus, inferior petrosal sinus, glossopharyngeal meatus, vagal meatus, internal acoustic meatus, facial nerve canal, greater superficial petrosal nerve, vestibular aqueduct, extraosseous portion of the endolymphatic sac, round and oval window, processus cochleariformis and pyramidal eminence. The 3D model showed detailed structure of the external and internal petrous bone, as well as their spatial relationship. The present study suggests the feasibility of comprehensive 3D reconstruction of the petrous bone using unstained celloidin sections, which may provide advantages for future study.

Carotid Artery Compression Caused by the Cochlea.

We investigated the possible interference between the human internal carotid artery and the cochlea. The cochlea and the internal carotid artery (ICA) are anatomically closely related in the human temporal bone. The intimacy may even result in functional interferences. Here, we analyzed 324 human plastic inner ear corrosion casts including the ICA canal and jugular bulb. Results showed that in 23% (14 cases), the cochlea caused physical impression in the carotid canal (CA) with luminal restriction. In one case, there was no separation between the CC and the basal turn of the cochlea. The distance between the CC and the cochlea varied between 0 and 1 mm among these 14 specimens. The lumen restriction of the CC in the pyramid-axial projection varied between 39% and 79%. We speculate that the reduction in ICA canal lumen size caused by the cochlea may form a predilection site for intratemporal ICA plaque formation and therefore be clinically relevant.

Cochlear implant electrode misplacement: Incidence, evaluation, and management

To review the presentation and management of improper electrode array placement, and to help guide clinical decision-making. Retrospective case series. Pediatric and adult cochlear implant patients managed from January 2001 to present whose electrode arrays were not placed properly within the cochlea or extended beyond the cochlea into the internal auditory canal or adjacent structures. Four patients, three pediatric and one adult, were identified from over 824 cases (< 1%) managed over the study duration. All cases had normal cochlear anatomy. These cases were initially identified due to poor auditory skill development or absent behavioral responses following implantation, which prompted imaging. Two patients presented several years after surgery. Sites of improper placement included the eustachian tube, vestibule, internal carotid artery canal, and internal auditory canal (IAC). Intraoperative findings and management are reviewed. Electrode array malpositioning is a rare, but serious and correctable complication in cochlear implant surgery. A multidisciplinary approach, including prompt audiologic evaluation and imaging, is important, particularly when benefit from the implant is limited or absent. Management of electrode arrays in the IAC may be more challenging.

Pseudoaneurysm of petrous internal carotid artery presenting as aural polyp

A 62-year-old male presented with a rare case of pseudoaneurysm of petrous internal carotid artery (ICA) caused by chronic otitis media manifesting as right aural polyp. There was massive bleeding following aural polypectomy and histopathology came as inflammatory polyp. HRCT temporal bone showed defect in petrous part of right ICA canal and features suggestive of cholesteatoma. CT angiogram showed a laterally directed aneurysm from the junction of horizontal and vertical segment of petrous ICA. Right ICA trapping done using coil embolization. Postcoiling angiogram showed nonopacification of aneurysm and good cross circulation from opposite side. After two months right modified radical mastoidectomy was done and intraoperative findings showed automastoidectomy with cholesteatoma filling mastoid and middle ear and erosion of ossicles. There was no postoperative complications and patient is now on regular follow-up and is asymptomatic. Psedoaneurysm of petrous ICA is rare and psedoaneurysm as a complication of chronic otitis media is extremely rare.

Aberrant internal carotid artery in the middle ear with a deficiency in the origin of the anterior cerebral artery: A case report

An aberrant internal carotid artery (ICA) in the middle ear is rare and difficult to diagnose, and may lead to severe complications. We present here a case of aberrant ICA with a deficiency in the origin of the anterior cerebral artery. The only symptom was aural fullness, and a nonpulsatile and white tympanic mass in the anteroinferior area was noted. Computed tomography (CT) and magnetic resonance angiography (MRA) are useful tools that provide excellent visualization of the temporal bone for the diagnosis of aberrant ICA by the following features: intratympanic mass, enlarged inferior tympanic canaliculus, absence of the vertical segment of the ICA canal, and absence of bone covering the tympanic portion of the ICA. In addition, in this case, a deficiency in the origin of the anterior cerebral artery on the same side was identified by MRA, and cerebral arteriography and a carotid occlusion test were performed. Because of the deficiency in the origin of the anterior cerebral artery, the ICA compression revealed that there was almost no cross flow from the other ICA. Our experience illustrates that after confirmation of the diagnosis of aberrant ICA, localized treatment and/or surgical procedures should be considered carefully.

Aberrant Internal Carotid Artery in the Temporal Bone

To describe the clinical and radiological features of the vascular anomaly aberrant internal carotid artery (ICA) in the temporal bone and to discuss management strategies. Retrospective study. Sixteen cases of aberrant ICA were diagnosed between 1982 and 2003. Of 16 cases, 11 were recognized by imaging assessment, 4 were recognized during middle ear surgery, and 1 was recognized clinically. Among the 11 cases, 8 malformations were diagnosed because of otologic symptoms related to the abnormal ICA or chronic otitis, while the other 3 were identified incidentally because of an underlying accompanying disease. In 4 cases, the diagnosis was made during surgery related to chronic otitis media (n = 2) or conductive hearing loss (n = 2). In these 4 cases, massive bleeding resulted from surgical injury to the vessel. Packing the external auditory canal and the middle ear first controlled the bleeding. Endovascular procedure was required in 2 cases to exclude an aneurysm or to control bleeding but was followed by anterior cerebral stroke in 1 case. The aberrant ICA could be identified on computed tomographic scan by the following features: intratympanic mass, enlarged inferior tympanic canaliculus, absence of the vertical segment of the ICA canal, and absence of bone covering the tympanic portion of the ICA. Conventional angiography was mandatory when intervention was planned to control bleeding or aneurysm. This study highlights that aberrant ICA has to be identified before any middle ear surgery because misdiagnosis may lead to dramatic surgical complications, whereas diagnosis with computed tomographic scan is easy. Bleeding is a minor complication compared with the putative neurologic deficit due to endovascular occlusion.

Vascular anomalies, sutures and small canals of the temporal bone on axial CT

Purpose: Subtle bony structures, small canals and fine sutures cause sometimes problems in the analysis of CTs of the temporal bone. The aim of this study was: to analyze the visibility of subtle structures and to estimate the incidence of vascular anomalies. Patients and method: We retrospectively analyzed axial scans of 223 high-resolution CTs of the temporal bone obtained as single slice or spiral CT with 1 mm slice thickness. All CTs had clinical indications. Two experienced radiologists studied CTs regarding the visibility of the fine sutures, fissures and small canals and the occurrence of vascular anomalies. Results: The following structures were seen commonly: sphenosquamosal suture (76%), arcuate artery canal (93%), vestibular aqueduct (89%), mastoid emissary vein (82%), singular canal (56%). Not so commonly were observed: tympanosquamosal suture (31%), mastoid canaliculus (28%), lateral sigmoid sinus (28%), petrotympanic fissure (24%), tympanomastoid suture (10%). Seldom we identified: the inferior tympanic canaliculus (6%), high jugular bulb (6%), anterior sigmoid sinus (5%), dehiscent internal carotid artery canal (2%), persistent petrosquamosal sinus (1%), dehiscent jugular bulb (1%). Persistent stapedial artery, aberrant internal carotid artery, dehiscent jugular bulb, high jugular bulb with diverticulum, anterior and dehiscent sigmoid sinus were detected in below 1% of the analyzed temporal bones. The frequency of asymmetry of the jugular foramen, which varied between 3% and 42%, depended on different criterions of size. Conclusion: A profound knowledge of normal anatomy and anomalies of the temporal bone avoids misinterpretation as pathological lesions and iatrogenic bleedings.