Diagnostic efficacy of high-resolution computed tomography findings in patients of chronic suppurative otitis media atticoantral type

<p><strong>Background: </strong>High resolution computed tomography (HRCT) provides information about anatomy and pathology of temporal bone and middle ear cleft, thus becoming important imaging modality in diagnosis and pre-operative planning in patients of chronic suppurative otitis media (attico-antral) CSOM (AA) type. The aim of study was to study disease extension and plan surgery accordingly in patients of CSOM (AA) and to study correlation between the HRCT findings and intra-operative findings of CSOM (AA) like soft tissue density mass, ossicular chain erosion, facial canal dehiscence, semi-circular canal erosion.</p><p><strong>Methods: </strong>Study of 70 patients clinically diagnosed of having CSOM (AA) in period between August 2018 to March 2020 was done at Sola civil hospital, Ahmedabad. All patients were advised HRCT temporal bone except those who had contraindications to CT scan, analysed and operated. Pre-operative CT-scan findings and intra-operative findings were compared for statistical analysis.</p><p><strong>Results: </strong>Soft tissue density was found in 100% of cases on HRCT temporal bone. Bony erosion seen in 25% of cases. 90% showed ossicular erosion. Lateral semi-circular canal fistula was observed in 10% of cases with facial canal dehiscence in 10% of cases. Intra-operative findings showed accuracy of HRCT in detecting soft tissue density to be 100%; bony erosion was observed in 25% cases. 10% patients had lateral semi-circular canal fistula. Facial canal dehiscence was seen in 15% cases.</p><strong>Conclusion: </strong>HRCT has proved quite useful and reliable to identify the disease extension before surgery and plan surgery accordingly.<p> </p>

Relationship Between Ossicular Chain Erosion and Facial Canal Dehiscence in Chronic Otitis Media Squamous

Introduction Chronic otitis media squamous is a gradually expanding destructive lesion and leads to complications by eroding the adjacent structures. Facial canal and ossicles are in close proximity in the middle ear space and they share the same pathogenesis of the bony erosion. Ossicular chain erosion found intraoperatively due to cholesteatoma, may suggest the likelihood of facial canal dehiscence. This study was conducted to assess the relationship between ossicular chain erosion and facial canal dehiscence in chronic otitis media squamous. MethodsIt is a retrospective chart review of patients who had mastoidectomy done for chronic otitis media squamous in Tribhuvan University Teaching Hospital from January 2014 to December 2018. The operative findings of facial canal dehiscence were correlated with ossicular chain status. ResultsAmong 158 cases, facial canal dehiscence was seen in 20 (12.7%), of which, 19/20 (95%) had ossicular erosion. Majority (90%) of dehiscence was in the horizontal segment. Incus was the most common ossicle to be eroded. Among the ossicles, stapes erosion was related to the facial canal dehiscence with odds ratio of 3.216 (1.235-8.374) and p-value 0.03. ConclusionAmong the ossicles, there is a relationship between the stapes erosion and the facial canal dehiscence in chronic otitis squamous. Erosion of ossicular chain especially stapes should alert surgeons towards the possibility of facial canal dehiscence.

Can MDCT Scan of the Temporal Bone Looking at Pneumatization Predict Surgical Vulnerability of the Facial Nerve?

Objectives: The aim of this study is to investigate the scutum–cochleariform process (CP) and scutum–promontorium distances according to the mastoid pneumatization condition. Methods: Two hundred temporal multidetector computed tomography scans (90 males and 110 females) were evaluated retrospectively. The scutum-CP and scutum–promontorium distances were measured. Facial canal dehiscence (FCD) in the tympanic segment and mastoid pneumatization were also evaluated. Results: The distances between scutum-CP and scutum–promontorium were not different between males and females and between right and left sides. Facial canal dehiscence in the tympanic segment was detected: 5.6% (right) and 7.8% (left) in males and 5.5% (right) and 10.0% (left) in females. Grade 4 (100%) pneumatization was detected mainly in 55.6% to 57.8% of the patients in both genders. Grade 0 (0%) pneumatization (sclerosis) was detected in 22.2% to 28.2% of both males and females. In more pneumatized mastoids, the scutum-CP and scutum–promontorium distances increased. In sclerotic mastoids, the scutum-CP and scutum–promontorium distances decreased. Facial canal dehiscence rates were not related to the mastoid pneumatization levels. Conclusion: Cochleariform process is an important landmark to localize the tympanic segment of the facial canal. In sclerosed mastoids, scutum-CP and scutum–promontorium distances decreased. There was no relationship between FCD rates and mastoid pneumatization levels. It may be due to the development of FCD that occurs during the intrauterine period. In endoscopic and classic ear surgeries, mastoid pneumatization must be evaluated preoperatively to avoid facial nerve injuries.

Cautionary Findings for the Presence of Facial Canal Dehiscence During Cholesteatoma Surgery

Our aim was to investigate the relationship between facial canal dehiscence (FCD) and surgical findings and procedures in patients with cholesteatoma. A total of 186 patients (118 males, 39.2 ± 15 years) who underwent surgery for advanced cholesteatoma between 2013 and 2018 were included in the study. The relationship between FCD and surgical findings was investigated via the surgical registries. The prevalence of FCD was 36.6% (68/186). The prevalence of FCD was 44%, and 13.2% for the patients who underwent canal wall down mastoidectomy (62/141) and canal wall up mastoidectomy (6/45), respectively ( P < .001). Facial canal dehiscence was detected in 73.9% of the 23 patients who had a lateral semicircular canal (LSCC) defect ( P < .001), in 61.9% of 21 patients who had a tegmen tympani defect, and in 58.1% of the 31 patients who had erosion on the posterior wall of the external auditory canal (EAC; P < .05). The prevalence of FCD was 3.1% in patients with isolated incus erosion, 59.1% in patients with erosion of malleus and incus, 60.7% in patients with erosion of stapes suprastructure and incus, and 43.2% in patients with whole ossicular chain deformation ( P < .001). The defects on LSCC, EAC, tegmen tympani, and malleus and incus might be cautionary findings for the presence of FCD during cholesteatoma surgery.

Is there a relationship between mastoid pneumatisation and facial canal dimensions?

ObjectiveTo evaluate mastoid pneumatisation and facial canal dimensions.MethodIn this retrospective study, 169 multidetector computed tomography scans of temporal bone were reviewed. Facial canal dimensions were evaluated at the labyrinthine, tympanic and mastoid segments using axial and coronal multidetector computed tomography scans of temporal bone. Mastoid pneumatisation and facial canal dehiscence were evaluated. Facial canal dehiscence was measured if it was found to be present.ResultsThis study showed that facial canal dimensions decreased in pneumatised mastoids. Facial canal dimensions in females were smaller than in males. Facial canal dehiscence was detected in 5.9 per cent and 6.5 per cent of the patients on the right and left sides, respectively. No correlations were found between facial canal dehiscence and mastoid pneumatisation. The length of dehiscence was 1.92 ± 0.44 mm (range, 0.86–2.51 mm) on the left side. In older subjects, left facial canal dehiscence was detected more, and the length of the dehiscence increased.ConclusionThis study concluded that during surgery, facial canal dehiscence should be kept in mind in order to avoid complications.