Segment Of Facial Canal Research Articles

Incidence of Facial Canal Dehiscent Noted Intraoperatively in Unsafe Chronic Suppurative Otitis Media: A Retrospective Study

Background: Dehiscence of the facial canal is a matter of great concern for an otologist as one of the most dreaded complications of mastoid surgery is injury to the facial nerve study was carried to determine the intra operative presence of facial canal dehiscence in primary and revision cholesteatoma surgery in a tertiary care centre. And also, our second goal was to identify association between FCD and other intra-operative pathological findings such as labyrinthine fistula, Dural plate dehiscence, sinus plate dehiscence in a group of patients with cholesteatoma surgery. Methods: A retrospective study was carried out in the department of Otorhinolaryngology in a tertiary referral hospital, Gujarat among 302 patients. The study’s inclusion criterion was primary and revision CWU and CWD tympano-mastoidectomy in patients who suffered from (CSOM) with cholesteatoma and exclusion criterion was charts with inadequate documentation. In addition, tympanoplasty cases were excluded as the study evaluated both tympanic and mastoid segments of facial nerve canal. Pre-operative clinical data and intra-operative findings were documented in a formatted questionnaire. Results: It was found that the incidence of FCD in our study of unsafe CSOM surgery was 21.22%. Conclusions: The surgeon should keep in mind during the procedures performed in the middle ear could potentially traumatize or damage the facial nerve at the site of dehiscence. A longer duration and more extensive cholesteatoma increase the chance of finding a dehiscent facial nerve. To this, we can prevent facial nerve paralysis and other complications in post-operative period and reduce the rate of morbidity.

Assessment of Mass Effect Sign at High-Resolution Computed Tomography in Prediction of Cholesteatoma.

The aim of this study was to assess the accuracy of mass effect sign in the diagnosis of cholesteatoma at high-resolution computed tomography (HRCT). This prospective study included 32 ears in 24 patients with chronic otitis media who underwent HRCT of the temporal bone. Otoscopic and operative notes were recorded. Image analysis was done both qualitatively and quantitatively. In the qualitative analysis, mass effect was evaluated visually by comparing both ears together in 4 certain anatomical sites. Ossicular erosions, erosion of tegmen tympani, erosion of tympanic segment of facial nerve canal, and the presence of lobulated nondependent opacity were also evaluated. In the quantitative analysis, we calculated the difference between the distances of the described anatomical sites in both ears. Qualitative analysis of mass effect sign showed 97.1% accuracy in detecting cholesteatoma. Ossicular erosions showed 69.2% accuracy in the diagnosis of cholesteatoma. In the quantitative analysis, we found that the cutoff point of 0.45 mm in the difference of aditus measure between both ears showed 85.3% accuracy in differentiating cholesteatoma from otitis media. The cutoff point of 0.75 mm in the differences in supratubal measure showed 86.1% accuracy. The cutoff point of 0.45 mm in the medial to incus measure showed 100% accuracy. High-resolution computed tomography is highly valuable for the detection of mass effect sign, which has great importance in diagnosing cholesteatoma.

RETRACTED: Variations in the labyrinthine segment of facial nerve canal revealed by high-resolution computed tomography

To study variations in the labyrinthine segment of fallopian canal and the associated middle and inner ear malformations. The high-resolution computed tomography (HRCT) images of the temporal bone in 24 patients with congenital variations in the labyrinthine segment of fallopian canal were analyzed retrospectively. The length of labyrinthine segment of the facial nerve and angle of the first genu of 10 normal subjects were also measured. Based on the original axial images, multi-planar reformation (MPR) and curved-planar reformation (CPR) images of bilateral ossicular chains, inner ear structure and fallopian canal were reconstructed. HRCT features of congenital variations in the labyrinthine segment of the facial nerve were analyzed, including its beginning site, dehiscence, length, angle of the first genu and the associated middle and inner ear malformations. Among the normal subjects, the length of labyrinthine segment of the facial nerve was 3.56±0.41mm, and angle of the first genu was 71.87±8.09°. Five types of variations in the labyrinthine segment of the facial nerve were found in 45 ears of 24 cases, including dehiscence in geniculate fossa in 25 ears, anteromedial displacement at the beginning site in 27 ears (widening of Bill's bar in 7 cases), enlargement of the angle of the first genu in 30 ears with an average value of 107.2° (96.0-126.0°), increase of length in 30 ears with an average length of 6.8mm (5.2-8.3mm) and bifurcation in one ear. Associated middle ear malformation in 6 ears and inner ear malformation in 36 ears were also found. A variety of congenital variations may occur in the labyrinthine segment of the facial nerve and they are often associated with middle or inner ear malformations, which can be clearly displayed by HRCT with MPR or CPR images.

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.

Correlation of HRCT mastoid with clinical presentation and operative findings in ear diseases

<p class="abstract"><strong>Background:</strong> <span lang="EN-IN">HRCT is found to be extremely useful for evaluating the ear diseases involving the external auditory canal, middle ear cavity, vertical segment of facial nerve canal, vestibular aqueduct, tegmen tympani, sigmoid sinus plate, sinodural angle, carotid canal, jugular fossa, infra and supralabrynthine air cells and temporomandibular joint.<strong> </strong>Our main objective was to correlate the clinical presentation and operative findings of ear diseases with HRCT mastoid. </span></p><p class="abstract"><strong>Methods:</strong> <span lang="EN-IN">This study is done in our institute otorhinolaryngology dept. from April 2014 to April 2016. This is prospective study involves 36 patient belonging to different age and sex groups with high suspicious of ear diseases. We have taken detail history of each patient with complete ear nose throat examination done and after that all patient were investigated with routine blood investigation, X-ray and HRCT mastoid to correlate clinical finding and subjected for operation to compare operative findings with HRCT finding. </span></p><p class="abstract"><strong>Results:</strong> <span lang="EN-IN">Determined using Pearson chi square test indicated a statistically significant correlation between HRCT temporal bone with clinical presentation and operative findings of ear diseases (p<0.05). </span></p><p class="abstract"><strong>Conclusions:</strong> <span lang="EN-IN">With the advent of modern high-resolution CT scanners, detailed demonstration of temporal bone anatomy is practically possible now. We have been able to identify many significant structures not demonstrated by any of the known imaging modalities. The improved contrast and soft tissue a definition possible with HRCT has resulted in production of excellent images of soft tissue lesions in air spaces. Hence HRCT appears to be the diagnostic modality of choice for cholesteatomas and other soft tissue lesions in middle ear.</span></p>

Incidence of Facial Nerve Canal Dehiscence in Primary and Revision Cholesteatoma Surgery.

The aim of this retrospective study was to determine the incidence of facial canal dehiscence (FCD) in primary and revision cholesteatoma surgery in a tertiary referral center. Moreover, our second goal was to identify association between FCD and other intra-operative pathological findings in a group of patients with cholesteatoma surgery. Inclusion criteria were primary and revision canal wall up and canal wall down tympanomastoidectomy in patients who suffers from chronic otitis media (COM) with cholesteatoma. An exclusion criterion was charts with in adequate documentation. In addition tympanoplasty cases were excluded due to evaluate both tympanic and mastoid segments of facial nerve canal. Preoperative clinical data and intra-operative findings were documented in a formatted questionnaire. We found the incidence of FCD in COM surgery was 18%. There was no difference between the primary and revision surgeries regarding its incidence. In addition, there was association between some preoperative or intra-operative findings of COM, such as middle fossa dural dehiscence, external auditory canal polyp, facial nerve paralysis, labyrinthine fistula, and FCD. In conclusions we found that there was no difference between primary and revision surgeries regarding the incidence of FCD. Surgeons should consider effective measures to prevent intra-operative facial nerve trauma in COM surgeries.

CT study on the development of facial nerve canal in children

Objective: To assess the characteristics of facial nerve canal between normal anatomy and dysplasia of children in different ages. Methods: A total of 492 health ears were divided into six groups, neonatal group (<1 m , n=42), infancy group(1 m-1 y, n=106), toddler group(1-3 y, n=102), preschool group (3-6 y, n=100), school group(6-10 y, n=60)and adolescent group (10-14 y, n=82). The length and diameter of facial nerve canal and that angles of first and second genu were measured with CT in each group. Results: ①The lengths of facial nerve canal in neonatal and infancy group were shorter than other four groups, especially in the mastoid segments of facial nerve canal. The lengths of mastoid segments in neonatal, infancy, toddler, preschool, school and adolescent groups were 5.03±0.84, 6.25±1.40, 8.34±1.38, 9.70±1.34, 10.84±1.41 and 12.17±1.83 mm, with P<0.05, respectively. After school age, the lengths of labyrinthine and tympanic segment grew slowly or developed completely (P>0.05). ② The diameter of labyrinth and tympanic segment in neonatal group were narrower than other five groups (P<0.05), but no significant difference among them in other groups (P>0.05). ③The dysplasia of facial nerve canal were occurred on 978 locations. Among them, the percentage of dehiscence, aberrance, partially expanding and bifurcation were 72.9%(713/978), 5.1%(50/978), 18.9%(185/978) and 3.1%(30/978) respectively. The percentage of dehiscence in geniculate fossa segment was decreased significantly with age (neonatal group 85.7%(36/42), infancy group 59.4%(63/106), toddler group 39.2%(40/102), preschool group 33%(33/100), school group 30%(18/60)and adolescent group 26.8%(22/82), with P<0.05). Except the dehiscence of geniculate fossa and mastoid segment, there was no significant difference in the occurrence rate of the other variants (P>O.05). Conclusions: The growth of length and dehiscence in labyrinth segment of facial nerve canal are significant in difference ages. The changes of diameter and angles of first and second genu in facial nerve canal, and the rate of other dysplasia are individual.

Study of demonstrating main operative section of facial recess approach using double oblique multiplanar reconstruction on multislice CT

Objective To explore the method of demonstrating main operative section of facial recess approach with multi-slice CT by using double oblique muttiplanar reconstruction.Methods Similarly as surgical procedure of facial recess approach,30 (60 eras) normal temporal bones in cadavers were reconstructed to observe main operative sections and anatomical marks.Main images of operative section of facial recess approach were reconstructed using double oblique multiplanar reconstruction on multislice CT.With the reference of operative anatomical marks,the ratios of visibility of anatomical marks on the transverse plane,coronal plane,sagittal plane and double oblique were calculated and compared.The degree,of which major anatomical landmarks were displayed on the same plane ( axial,coronal,sagittal,or doubleoblique sagittal plane),was classified using the following criteria: level 4: 100％ of anatomical landmarks were presented in the same plane; level 3: 90％ to 99％ of anatomical landmarks were presented in the same plane; level 2: 80％ to 89％ of anatomical landmarks were presented in the same plane; level 1: 70％ to 79％ of anatomical landmarks were presented in the same plane ; level 0: ＜ 70％ of anatomical landmarks were presented in the same plane.Classification data were tested by chi-square test.Results Four key operative section were involved in facial recess approach,which were of oblique sagittal orientation.The central mark of the first key operative section was semicircular canal by using double oblique multi-planar reformation.On reconstructed images of the first key operative section,horizontal reference line was short process of incus,and the angle adjusting the reference line on the transverse plane was 22.15° ±5.22°.On the reconstructed images of the first key operative section,coronal reference line was tympanic segment of facial canal,and the angle adjusting the reference line on the coronal plane was 14.35° ± 4.02°.On the reconstructed images of the second key operative section,the central mark was fossa incudis,the horizontal reference line was short process of incus and the angle was 20.15° ± 5.52°,while the coronal reference line was tympanic segment of facial cana,and the angle was 13.15° ± 3.33°.On the reconstructed operative images of the third key section,the central mark was pyramidal eminence,the horizontal reference line was the horizontal portion of the facial nerve and the angle was 32.53° ±5.22°,while the coronal reference line was the tympanic segment of facial nerve,and the angle was 15.05° ± 4.43°.On the fourth reconstructed images of the key operative section,the central mark was the posterior border of round window,the horizontal reference line was the superior border of oval window,and the angle was 50.15° ± 8.02°,while the coronal reference line was the tympanic segment of facial nerve,and the angle was 15.25° ± 4.12°.For the four planes (double-oblique sagittal,axial,coronal,or sagittal plane),the results of the degree to which they could include the major anatomical landmarks in the same layer of the first section were: level 4 in 60 sides,level 2 in 12 sides and level 3 in 48 sides,level 2 in 15 sides and level 3 in 45 sides,level 3 in 10 sides and level 4 in 50 sides,respectively.The results of the second section were: level 4 in 60 sides,level 2 in 11 sides and level 3 in 49 sides,level 2 in 13 sides and level 3 in 47 sides,level 3 in 11 sides and level 4 in 49 sides,respectively.The results of the third section were: level 4 in 60 sides,level 2 in 10 sides and level 3 in 50 sides,level 2 in 11 sides and level 3 in 49 sides,level 3 in 9 sides and level 4 in 51 sides,respectively.The results of the fourth section were: level 4 in 60 sides,level 2 in 9 sides and level 3 in 51 sides,level 2 in 8 sides and level 3 in 52 sides,level 3 in 5 sides and level 4 in 55 sides,respectively.The four planes differed significantly in the degree to which they could include the major anatomical landmarks in the same layer ( x2 =123.3200,121.4231,122.4011,125.4213,all,P ＜ 0.05 ).The visibility ratio of every section is 100％ (60/60).Conclusion Double oblique multi-planar reformation is a new method to demonstrate landmarks of operative section of facial recess approach in one slice.The reconstructive images of operative section with double oblique multi-planer reconstruction may provide valuable information for operation. Key words: Temporal bone; Tomography, X-ray computed; Anatomy, regional; Otologic surgical procedures