Jugular Bulb Position Research Articles

Radioanatomical evaluation of the subtympanic sinus in children under five years old and its clinical implications - high resolution computed tomography study.

This study aimed to evaluate subtympanic sinus (STS) and its vicinity in high-resolution computed tomography (HRCT) scans of children under five years old with non-diseased temporal bones. We divided the whole group into children under 24 months of age (first stage of pneumatisation development) and between 25 and 60 (second stage). We have determined the width of the entrance to STS, depth of the STS, type in relation to facial nerve according to Anschuetz classification, the pneumatisation of posterior and medial air cell tracts, and jugular bulb position. All the HRCTs (280 temporal bones) were analyzed according to the multiplanar reconstruction protocol with symmetrization. STS's mean width and depth were 2.71 ± 0.60mm and 3.26 ± 1.11mm, respectively. The most common STS type was type A (59.3%), followed by type B (30.7%) and type C (10%). The posterior air cell tract (retrofacial cells) was present in 39.3%. The medial air cell tract (hypotympanic cells) was present in 30.7% The jugular bulb position affected the final shape of STS in 17.5%. The results support the necessity of the classification for the STS. Our study may help with surgical planning regarding endoscopic ear procedures and gives a broader understanding of how pneumatization or jugular bulb might correlate with the final shape of the retrotympanum. The historical remarks track the term's origin for clarity in research and respect for earlier investigators.

Jugular bulb and skull base pathologies: proposal for a novel classification system for jugular bulb positions and microsurgical implications.

OBJECTIVE There is no definitive or consensus classification system for the jugular bulb position that can be uniformly communicated between a radiologist, neurootologist, and neurosurgeon. A high-riding jugular bulb (HRJB) has been variably defined as a jugular bulb that rises to or above the level of the basal turn of the cochlea, within 2 mm of the internal auditory canal (IAC), or to the level of the superior tympanic annulus. Overall, there is a seeming lack of consensus, especially when MRI and/or CT are used for jugular bulb evaluation without a dedicated imaging study of the venous anatomy such as digital subtraction angiography or CT or MR venography. METHODS A PubMed analysis of "jugular bulb" comprised of 1264 relevant articles were selected and analyzed specifically for an HRJB. A novel classification system based on preliminary skull base imaging using CT is proposed by the authors for conveying the anatomical location of the jugular bulb. This new classification includes the following types: type 1, no bulb; type 2, below the inferior margin of the posterior semicircular canal (SCC), subclassified as type 2a (without dehiscence into the middle ear) or type 2b (with dehiscence into the middle ear); type 3, between the inferior margin of the posterior SCC and the inferior margin of the IAC, subclassified as type 3a (without dehiscence into the middle ear) and type 3b (with dehiscence into the middle ear); type 4, above the inferior margin of the IAC, subclassified as type 4a (without dehiscence into the IAC) and type 4b (with dehiscence into the IAC); and type 5, combination of dehiscences. Appropriate CT and MR images of the skull base were selected to validate the criteria and further demonstrated using 3D reconstruction of DICOM files. The microsurgical significance of the proposed classification is evaluated with reference to specific skull base/posterior fossa pathologies. RESULTS The authors validated the role of a novel classification of jugular bulb location that can help effective communication between providers treating skull base lesions. Effective utilization of the above grading system can help plan surgical procedures and anticipate complications. CONCLUSIONS The authors have proposed a novel anatomical/radiological classification system for jugular bulb location with respect to surgical implications. This classification can help surgeons in complication avoidance and management when addressing HRJBs.

Radiological requirements for surgical planning in cochlear implant candidates.

Objective:This study is concerned with clarification of radiological findings that should be addressed and reported in patients listed for cochlear implant (CI) operation. These findings may force a surgeon to consider modifications of the surgical approach by a CI surgeon.Materials and Methods:The study was performed from January 2015 to January 2016. It included 50 patients with severe-to-profound sensorineural hearing loss who fulfilled the criteria for CI. Patients underwent CI surgery in the Department of Otolaryngology. All patients underwent preoperative computed tomography (CT) and magnetic resonance imaging (MRI) assessment in the Department of Diagnostic Radiology. Combined examination of the CT and MRI by the radiologist and the surgeon was advocated.Results:Many anatomical variants were observed regarding the pattern of mastoid pneumatization, position of middle cranial fossa dura, sigmoid sinus position jugular bulb position, and the size and position of the mastoid segment of facial nerve canal. Labyrinthitis ossificans was seen in 3 patients (6%), otospongiosis in 1 patient (2%), and dilated vestibular aqueduct and endolymphatic sac in 9 patients (18%).Conclusion:Cochlear implantation is a major treatment modality in patients with severe-to-profound sensorineural hearing loss. Radiological evaluation is integral in surgery planning.

The relationship between jugular bulb position and jugular bulb related inner ear dehiscence: a retrospective analysis

ObjectiveHigh jugular bulb (HJB) can erode inner ear structures creating a jugular bulb related inner ear dehiscence (JBID). The aim of this study was to analyze the relationship between the position of jugular bulb (JB) and JBID using high-resolution computed tomography (HRCT). Material and methodsIn this retrospective study HRCT images of 552 ears of 276 patients with hearing loss, otogenic vertigo, tinnitus or idiopathic peripheral facial nerve paralysis were analyzed. HJB type-1 was defined when JB dome reached above the inferior part of the round window, but was below the inferior edge of the internal acoustic meatus (IAM). HJB type-2 was defined when the dome of JB was higher than the inferior edge of IAM. The frequencies and types of HJB were evaluated. JBID for each HJB type was determined. Frequencies of JBID eroding the vestibular aqueduct (VA), the cochlear aqueduct and the posterior semicircular canal were examined. ResultsHJB type-1 and HJB type-2 were found in 19% (105/552) and in 15.8% (87/552) of studied ears. JBID showed to be in 3.8% (21/552) of all ears. 90.5% (19/21) of JBID revealed eroding of VA. Jugular bulb related cochlear aqueduct dehiscence and jugular bulb related posterior semicircular canal dehiscence were found in one ear each. The frequency of jugular bulb related vestibular aqueduct dehiscence (JBVAD) in patients with HJB reaching above IAM was higher than in patients with HJB lower than IAM. ConclusionsHJB is common, but JBID is rare. JBID prevalently erodes VA. HJB rising above IAM is most at risk to show JBVAD.

High Computed Tomographic Correlations between Carotid Canal Dehiscence and High Jugular Bulb in the Middle Ear

Both carotid canal dehiscence (CCD) and high jugular bulb (HJB) are thought to increase the potential for disastrous consequences during middle ear surgery. Clinical co-presentation of these two great vessel variants has not yet been described. This study aims to determine the relationship between CCD and HJB based on a computed tomographic (CT) temporal bone evaluation. High-resolution CT scans of 408 temporal bones obtained from 208 adults were recruited. Carotid canal integrity, jugular bulb position, petrous apex pneumatization and the minimal thickness of the carotid canal wall (TCW) facing the tympanic cavity were examined and measured for the incidence of CCD and/or HJB. Other variables including gender, age, laterality and the presence of otitis media or mastoiditis were also collected for analysis. CCD was found in 28 ears (6.9%); 19 of these were found to also have HJB (67.9%). The presence of CCD was significantly correlated with HJB presentation. The minimal TCW in HJB ears was significantly thinner than that of normally positioned jugular bulbs. Moreover, after controlling for other candidate variables, the independent factors of age (younger or older than 50 years) and jugular bulb position (high vs. normal) were found to predict the presence of CCD. In conclusion, HJB tends to coexist with a thinner carotid canal wall. This finding emphasizes the need to be watchful for the coexistence of these two great vessel anomalies when surgeons encounter an aged patient presenting either CCD or HJB during middle ear surgery.

High jugular bulb in the translabyrinthine approach to the cerebellopontine angle: anatomical considerations and surgical management

Evidence of a high jugular bulb position (HJBP) during the translabyrinthine approach may compromise the surgical removal of cerebellopontine angle (CPA) tumours. We report a simple surgical procedure to safely manage this frequent normal variation and comment on various alternative options. The translabyrinthine approach included a complete skeletonization of the sigmoid sinus and of the presigmoid dura. A thin eggshell bone was left at the jugular bulb surface. The dome of the jugular bulb was gently dissected from the jugular fossa and gradually retracted downward in a tailored way, allowing the surgeon to drill below the internal auditory meatus. A small piece of bone was wedged over the jugular dome in order to maintain its lowered position. Among 178 consecutive translabyrinthine approaches performed for the removal of large CPA tumors, the use of this procedure was required in 44 cases of HJBP. Excepting minimal venous bleeding easily controlled in several cases, we never observed any complication from this procedure nor failure to expose the inferior compartment of the CPA. The HJBP can be systematically diagnosed with the preoperative CT-scan using bone window imaging. Our results demonstrate that the described procedure is safe and effective to widen the operative corridor that is required for the exposure of the inferior compartment of the CPA in this anatomical situation.

Anatomical considerations of high jugular bulb in lateral skull base surgery.

In order to study high jugular bulb management in lateral skull base surgery, an anatomical study was conducted on 30 temporal bones by examining the relationship between the internal auditory canal (IAC) and the jugular bulb. The following parameters were measured: 1) Height of the jugular bulb (H)... distance between the level of jugular bulb dome and the line passing through the confluence of the sigmoid sinus with the jugular bulb (SS-JB), 2) Mastoid length (ML)... distance between the mastoid process and middle cranial fossa dura, 3) Distance between the most inferior part of the porus acousticus and jugular bulb dome (A), 4) Distance between the porus acousticus and SS-JB (B). The jugular bulb was defined as high when it occupied more than two thirds of (B). The incidence of a high jugular bulb was 23 per cent in this study. When the jugular bulb was high, the mean (H) and (A) were 9.4 +/- 1.9 mm and 2.7 +/- 0.5 mm, respectively. (H) was higher on the right side than on the left side. No statistically significant difference was found between small and large mastoids (t-test: p > 0.05). It was concluded that when a high jugular bulb was encountered during lateral skull base surgery, the jugular bulb position allows a very small working area inferior to the IAC. In these cases, a 3 or 4 mm depression of the jugular bulb is necessary in order to expose the lower cranial nerves. This can be accomplished by lowering the jugular bulb with the technique already described.

Asymptomatic high jugular bulb in the pediatric population

The jugular bulb is the connection between the-sigmoid sinus and the internal jugular vein with the upper extent of the bulb becoming rounded and lying in the jugular fossa. The jugular bulb is recognized as the vein and the surrounding bone. The jugular bulb may present in a variety of positions and dimensions within the temporal bone. In addition to the inconsistency of the jugular bulb position, the bony covering may be altered secondary to abnormal bone formation, remodeling, or infection. A dehiscent jugular bulb is an uncommon finding within the middle ear and should be recognized before middle ear exploration. In the pediatric population, the detection of a dehiscent jugular bulb is paramount to preventing serious and potentially fatal consequences when performing a myringotomy. Several investigators have previously reported a dehiscent jugular bulb within the middle ear. The first description was made by Page1 in

Jugular bulb position in the cranial base and its relation to cranial venous system

Target CT images of 147 patients and digital subtraction angiography (DSA) images of 15 patients were examined to assess the relation between jugular bulb position and intracranial veins. First, relation of jugular bulb position to venous volume was examined from CT. The height of the jugular bulb was measured from the lower margin of the tympanic annulus to the apex of the jugular bulb by counting CT slices individually on the both side. The heights of the right and left jugular bulbs were 4.0 +/- 3.9 mm and 2.0 +/- 3.9 mm respectively, indicating that the right jugular bulb was higher than the left, consistent with previous reports. The depth of the sigmoid sinus sulcus, which may reflect the venous volume, was measured on the slice showing the internal auditory canal. The right side was 6.7 +/- 2.2 mm deep, while the left side was 5.3 +/- 2.0 mm in depth. These measurement also showed that the height of jugular bulb and depth of the sulcus of the sigmoid sinus were closely related. The jugular bulb was higher on the side with the deeper sigmoid sinus sulcus (correlation coefficient r = 0.73). Frontal head and neck angiography were performed after bolus injection of contrast medium. Angiographic images were modified and examined by means of a digital subtraction process. A result from angiography was consistent with the measurement of CT. The side with greater venous flow has the higher jugular bulb. And such difference in right and left venous flows was observed at and pproximately to the transverse sinuses.(ABSTRACT TRUNCATED AT 250 WORDS)

Jugular bulb position and shape are unrelated to temporal bone pneumatization

The position and shape of the jugular bulb are undependable, and thus can add difficulty to temporal bone surgery. The present study addresses the hypothesis that position and shape of the jugular bulb correlate with the extent of temporal bone pneumatization. Systematic study was done in 25 unilateral cadaver specimens. Pneumatization was determined using both the classic Runström II radiograph, and computed tomography. Jugular bulb shape and position were determined by anatomic dissection and computed tomography. No association of jugular bulb shape or position, with pneumatization, was found. However, the dissection-determined distance from the plane of the lateral semicircular canal to the roof of the jugular bulb (2 to 15 mm), had a good correlation (r = 0.70, p less than .001) with the distance from the internal auditory canal to the apex of the jugular bulb (1.5 to 15.0 mm).