The dehiscent facial nerve canal

Post-traumatic Delayed Facial Nerve Palsy: Report of 2 Cases and Systematic Review

OBJECTIVE

Delayed facial nerve palsy (dFNP) secondary to head injury is definitely uncommon. Although the mechanism of immediate facial nerve paralysis is well-studied, its delayed presentation remains debated. Given the dearth of available information, we reported herein our experience with 2 cases of posttraumatic dFNP. This systematic review aimed to evaluate all available information on dFNP and to assess treatment outcome also comparing conservatively and surgically approaches.

DATA SOURCES

Pubmed, Scopus, and Web of Science databases were systematically screened.

REVIEW METHODS

The protocol of this investigation was registered on PROSPERO in April 2023 and the systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement.

RESULTS

Both patients in the case studies showed a complete recovery within 2 to 3 months after the head trauma. One of them still reported a subjective taste alteration at last control. After the application of the inclusion-exclusion criteria, 9 manuscripts with adequate relevance to this topic were included in the systematic review. The study population consisted of 1971 patients with a diagnosis of posttraumatic facial nerve palsy, of which 128 with a dFNP.

CONCLUSIONS

dFNP due to head trauma is a rarely encountered clinical entity, and optimal treatment still remains to be elucidated. Based on the reported data, it seems rational to propose a conservative approach for dFNP with steroid administration as a first line in most cases, indicating surgery in severe and/or refractory cases.

Endoscopic Findings on Facial Nerve Anatomy During Exclusive Endoscopic Stapedotomy: Clinical Considerations and Impact on Surgical Results

BACKGROUND

Variations along the facial nerve (FN) course present considerable challenges in the surgical treatment of otosclerosis, often complicating the procedure. Existing knowledge of its tympanic tract and its implications primarily comes from microscopical procedures. This study aims to assess endoscopic findings of FN anatomy in a healthy tympanic cavity and its impact on the stapedotomy procedure, focusing on the risk of complications and functional hearing outcomes.

METHODS

A retrospective study on exclusive endoscopic stapedotoplasties between October 2014 and October 2021 at our Otorhinolaryngology University Department was carried out. An evaluation of intraoperative endoscopic findings reviewed in surgical descriptive and/or video records was conducted to assess their potential negative impact on the surgery. Demographic data, preoperative and postoperative hearing thresholds, as well as intraoperative and postoperative complications were analyzed.

RESULTS

One hundred fifty-seven subjects were included. A FN partially overhanging the oval window was observed in 7.3% (n=12): 10 prolapsing with bony canal dehiscence and 2 without any detected dehiscence. Each procedure was successfully completed without any issues related to the anomalous anatomy, and in no case, switching to the microscope for the handling of the prosthesis near the dehiscent nerve was required. No facial paralysis occurred, with an early- or long-term postoperative House-Brackman grade of 1 (n=157, 100%). Only 3/157 patients (1.9%) showed a sensorineural threshold reduction of ≥20 dB HL, but a significant air-bone gap improvement was observed (mean closure of 18.36 dB HL, P -lt; .0001).

CONCLUSION

The endoscope promotes a concrete description of tympanic FN anatomy, and endoscopic stapes surgery appears to be a safe and viable option when dehiscent or prolapsed FNs reduce the footplate's exposure.

Impact of Intraoperative Findings on Hearing in Revision Ear Surgery

Introduction

Hearing results after chronic ear surgery encompass recurrence, localization and extent of cholesteatoma, type of surgery, ossiculoplasty methods, but rarely interpret intraoperative findings. This study aimed to analyze the impact of intraoperative findings in revision tympanomastoidectomy in predicting postoperative hearing.

Materials and Methods

This was a retrospective non-randomized cohort of 101 patients treated for recurrent chronic otitis media by tympanomastoidectomy. The patients' demographics, localizations of disease recurrence and perioperative hearing results were analyzed.

Results

Logistic regression showed that presence of tympanic perforation (p=0.036), ossicular chain damage (p=0.006), were negatively associated with improved hearing postoperatively. Attic cholesteatoma was associated with better postoperative hearing (p=0.045). Presence of tympanic perforation (p=0.050), alongside perifacial localization of imflammation (p=0.021) and ossicle destruction (p=0.013) were associated with worse postoperative hearing results. Multivariate analysis confirmed that tympanic perforation (p=0.040, F=4.401), and ossicular chain involvement (p=0.025, F=5.249), were consistent negative predictors of hearing improvement, while postoperative deterioration of hearing was associated with tympanic perforation (p=0.038, F=4.465) and facial nerve dehiscence (p=0.045, F=4.160).

Conclusions

Comparison of postoperative revision tympanomastoidectomy hearing outcomes revealed significant positive reductions in air-bone gap values, primarily at low and mid frequencies. Postoperative hearing results at high frequencies are not affected by revision surgery.

A Study of Intraoperative Incidence of Fallopian Canal Dehiscence in Cases of Cholesteatoma

Aims

Our study aimed to find the incidence of fallopian canal dehiscence during surgery for cholesteatoma, to compare this incidence with a homogenous control group (otosclerosis) and to find the incidence of a labyrinthine fistula if fallopian canal dehiscence is present.

Material and Methods

Prospective case control study design was used in the setting of a tertiary care referral center. Subjects included 60 patients. 30 patients diagnosed with cholesteatoma were taken as cases and 30 patients with conductive or mixed hearing loss suspected of otosclerosis were taken as controls. The method was identification of bony dehiscence under operating microscope. In case of finding of dehiscence of fallopian canal, presence of labyrinthine fistula was searched. The cases underwent modified radical mastoidectomy and controls underwent exploratory tympanotomy after giving a written informed consent. Institutional ethics committee clearance was obtained.

Results

Fallopian canal dehiscence was recorded in all subjects. 50% of cases and 3.3% of controls showed presence of fallopian canal dehiscence. This correlation was statistically significant (p < 0.001). Also 26.7% cases with fallopian canal dehiscence had a semicircular canal fistula (4 out of 15),but this finding was not significant (p = 0.100).

Conclusion

From our study it was evident that there were very high chances of finding a fallopian canal dehiscence in cases of cholesteatoma than in cases undergoing exploratory tympanotomy. Also, presence of labyrinthine fistula with fallopian canal dehiscence was likely but not significant.

A novel imaging scoring method for identifying facial canal dehiscence: an ultra-high-resolution CT study

OBJECTIVES

Facial canal dehiscence (FCD), typically found in the tympanic segment, is a risk factor for facial nerve injury. An imaging scoring method was proposed to identify FCD based on ultra-high-resolution CT.

METHODS

Forty patients (21 females and 19 males, mean age 44.3 ± 17.4 years), whose tympanic facial canal (FC) was examined during otological surgery, were divided into the FCD group (n = 29) and the control group (n = 11) based on surgical findings. Imaging appearance of tympanic FC was scored 0-3: 0 = no evident bony covering, 1 = discontinuous bony covering with linear deficiency, 2 = discontinuous bony covering with dotted deficiency, and 3 = continuous bony covering. Both lateral and inferior walls were assigned a score as L_FCD and I_FCD, respectively. An FCD score was calculated as L_FCD + I_FCD. The diagnostic value of the FCD score was tested using the ROC curve.

RESULTS

The inter-observer agreement was moderate for the lateral wall (Cohen's κ coefficient 0.416, 95% CI 0.193-0.639), and good for the inferior wall (Cohen's κ coefficient 0.702, 95% CI 0.516-0.888). In the FCD group, the most common appearance for both walls was discontinuous bony covering with linear deficiency (L_FCD = 1, 22/29, 75.9%; I_FCD = 1, 15/29, 51.7%). An FCD score of less than 4 was associated with high sensitivity (0.82) and specificity (0.93) for identifying FCD, with an AUC of 0.928.

CONCLUSIONS

Using the proposed scoring method, FCD score < 4 could identify FCD of the tympanic segment with high concordance with surgical findings.

KEY POINTS

• Imaging appearance of the tympanic facial canal (FC) is divided into four types based on ultra-high-resolution CT images. • The most common appearance of FC with facial canal dehiscence (FCD) is discontinuous bony covering with linear deficiency. • An FCD score, consisting of scores of the lateral and inferior walls, less than 4 is highly indicative of FCD.

[Anatomical and clinical characteristics of the chorda tympani]

The article presents information about the applied and clinical anatomy of the chorda tympani. Brief information is given about the history of its discovery, embryonic and postnatal development, features of anatomy, topography and morphology. The clinical aspects of the lesion and methods of studying the function of the chorda tympani are described.

Osteoclast activity sculpts craniofacial form to permit sensorineural patterning in the zebrafish skull

Efforts to understand the morphogenesis of complex craniofacial structures have largely focused on the role of chondrocytes and osteoblasts. Along with these bone-creating cells, bone-resorbing osteoclasts are critical in homeostasis of adult skeletal structures, but there is currently limited information on their role in the complex morphogenetic events of craniofacial development. Fundamental aspects of skull formation and general skeletal development are conserved from zebrafish to mammals. Using a cathepsinK reporter, we documented osteoclast location in the developing zebrafish skull over several weeks, from 5.18 mm to 9.6 mm standard length (approximately 15 to 34 days post fertilization). While broad distribution of osteoclasts is consistent across individuals, they are sparse and the exact locations vary among fish and across developmental time points. Interestingly, we observed osteoclasts concentrating at areas associated with neuromasts and their associated nerves, in particular the hyomandibular foramina and around the supraorbital lateral line. These are areas of active remodeling. In contrast, other areas of rapid bone growth, such as the osteogenic fronts of the frontal and parietal bones, show no particular concentration of osteoclasts, suggesting that they play a special role in shaping bone near neuromasts and nerves. In csf1ra mutants lacking functional osteoclasts, the morphology of the cranial bone was disrupted in both areas. The hyomandibular foramen is present in the initial cartilage template, but after the initiation of ossification, the diameter of the canal is significantly smaller in the absence of osteoclasts. The diameter of the supraorbital lateral line canals was also reduced in the mutants, as was the number of pores associated with neuromasts, which allow for the passage of associated nerves through the bone. Our findings define important and previously unappreciated roles for osteoclast activity in shaping craniofacial skeletal structures with a particular role in bone modeling around peripheral cranial nerves, providing a scaffold for wiring the sensioneural system during craniofacial development. This has important implications for the formation of the evolutionarily diverse lateral line system, as well understanding the mechanism of neurologic sequelae of congenital osteoclast dysfunction in human craniofacial development.

Prevalence of facial canal dehiscence and other bone defects by computed tomography

INTRODUCTION

The facial nerve is the most vulnerable structure during otological surgeries. Facial canal dehiscence (FCD) is the main risk factor for iatrogenic injuries. Its prevalence in clinical studies ranges between 6 and 33.3%, while anatomical studies report 25-57%. The objective was to determine the prevalence of FCD stratified by age and gender in a healthy population.

MATERIALS AND METHODS

Temporal bones from high-resolution computed tomography (CT) were analyzed. Patients with a history of trauma or tumors of the temporal bone, cholesteatomas, chronic middle ear disease, and any pathology that could modify the bone's anatomy, were excluded.

RESULTS

A total of 184 temporal bones were included. FCD was observed in 94 (51.2%) of the analyzed bones. The tympanic portion was the most frequently affected site with 91 (49.5%), followed by the mastoid segment with 3 (1.6%). No dehiscence was found in the labyrinth portion. We observed 30 (31.9%) of the FCD involved the oval window. Other bone defects identified with the FCD included: 11 (11.7%) with a lateral semicircular canal fistula and 7 (7.4%) with tegmen tympani erosions.

CONCLUSION

FCD has a high prevalence among healthy patients. A pre-surgical otological evaluation using high-resolution CT should be indicated to properly assess the patient and reduce the risk of injury.

Correlation between Surgical Outcome and Stage of Acquired Middle Ear Cholesteatoma: Revalidation of the EAONO/JOS Staging System

OBJECTIVES

This study aimed to evaluate the intraoperative findings, recurrence rate, and hearing outcome of cholesteatoma surgery and correlate them with the newly proposed EAONO/JOS Joint Consensus Statement.

MATERIALS AND METHODS

The records of 407 patients diagnosed with chronic otitis media and cholesteatoma between 2009 and 2017 were reviewed. After the exclusion of records with unsatisfactory surgical notes and anamnesis, 353 patients were included in the study. The 290 patients who had undergone primary surgery and 63 who had undergone revision surgery were evaluated separately.

RESULTS

Total 162 of 290 (56%) patients had retraction pocket cholesteatoma and 128 of 290 (44%) patients had non-retraction pocket cholesteatoma. Eighty (28%) patients had stage I, 114 (39%) had stage II, 91 (31%) had stage III, and 5 (2%) had stage VI disease. The recurrence rate was 6.9% (20/290). The average age of these patients at the time of the second operation was 23.31±10.3 years. Twelve patients had (60%) recurrent cholesteatoma, and eight (40%) had residual cholesteatoma. Hearing outcome and surgical technique were significantly associated with the disease stage; however, the recurrence rate showed no such association.

CONCLUSION

We concluded that the EAONO/JOS staging system is beneficial for estimating the postoperative hearing results and planning the surgical technique. However, there was no significant relationship between the recurrence rate and the EAONO/JOS staging system. We believe that additional factors, such as infection, ossicles, and invasion, predict the recurrence. Widespread use of the EAONO/JOS staging system will enable better evaluation of surgical outcomes and prognosis.

Radioanatomic Assessment of the Geniculate Ganglion Dehiscence and Dimension: A Cadaveric Study

OBJECTIVE

The main aim of this study placed on cadavers was to compare the data related to geniculate ganglion (GG) dehiscence and dimension obtained from computed tomography (CT) with dissection values.

METHODS

This study was conducted on 20 temporal bones obtained from 10 cadavers (4 female, 6 male) aged between 45 and 92 (71.50 ± 15.98) years. All the measurements related to GG dimension were performed with a CT scanner and microdissection.

RESULTS

The size of GG including its area, length, and width did not show statistically significant differences in terms of sex, side, and assessment method (CT and cadaveric dissections). The dehiscent GG was observed in 6 (30%) and 5 (25%) out of 20 temporal bones in CT and cadaveric dissections, respectively. The presence and absence of GG dehiscence in CT and dissection were similar in 75%.

CONCLUSIONS

Our findings based on dissection data suggest that radiologic evaluation of dehiscent GG detection might be erroneous by 25%, which highlights that surgeons should be careful when lifting the dura to prevent GG injury during middle cranial fossa surgical approaches. On the other hand, there was no statistical difference between CT and dissection measurements related to GG dimension.

Percutaneous Threshold of Facial Nerve Stimulation Predicts Facial Canal Dehiscence

Iatrogenic facial nerve (FN) injury is one of the most feared complications of otologic surgery. Dehiscence of the bony covering of the FN within the temporal bone increases FN vulnerability to accidental injury. High-resolution computed tomography (HRCT) of the temporal bone is used preoperatively to assess middle ear and mastoid anatomy; however, it is unreliable for detecting facial canal dehiscence. In this study, our aim was to determine if preoperative percutaneous FN stimulation could predict middle ear facial canal dehiscence. Between January 2015 and February 2017, we performed preoperative HRCT and percutaneous FN stimulation on adult patients who underwent otologic surgery at our institution. Stimulation was performed with a monopolar probe placed on the skin over the stylomastoid foramen. Electrical stimuli ranged from 0 to 40 milliamperes (mA). Recordings were made from ipsilateral facial muscles. Dependent variables included threshold to compound muscle action potential (CMAP), threshold to maximum amplitude of CMAP, and maximum amplitude of CMAP for each muscle. A retrospective chart review was performed. Seventy patients met inclusion criteria. Of the 24 with an intraoperatively confirmed dehiscence, 10 were identified preoperatively by the attending surgeon on HRCT. Averages of the lowest recorded threshold to CMAP (5.1mA v. 9.1mA), and an average of the threshold to CMAP (8.9 mA. 11.8 mA) of dehiscent versus non-dehiscent nerves were significantly different (p < .05). In conclusion, percutaneous FN stimulation is a simple and cost-effective tool that can give the surgeon important preoperative information about FN anatomy.

CT Imaging Categorization and Biomarker Study of Anomalous Tympanic Segment of the Facial Nerves in Patients With Hearing Loss in the Absence of Microtia

The purpose of this study is to categorize anomalous tympanic facial nerve (FN) on high-resolution computed tomography (HRCT) and to determinate the significance of associated temporal bone anomalies and congenital syndromes without microtia in patients with hearing loss. A retrospective analysis of HRCT findings in 30 temporal bones in 18 patients with anomalous FN was performed. Abnormalities of the tympanic FN were categorized as follows: category 1: FN medially positioned, but above the oval window; category 2: FN in the oval window niche; and category 3: FN below the oval window. Potential associated findings that were assessed included stapes abnormalities, oval window atresia, and inner ear anomalies, as well as the presence of a known congenital syndrome with hearing loss. The most common type of anomalous tympanic FN was category 1 (67%, n = 20), following by group 2 (20%, n = 6) and group 3 (13%, n = 4). Stapes anomalies were detected in 77% of temporal bones (n = 23), oval window atresia was detected in 43% of temporal bones (n = 13), and inner ear anomalies were detected in 70% of temporal bones (n = 21). Anomalous tympanic facial nerves in temporal bone with conductive hearing loss were often (60%) not associated with oval window atresia. The combination of aberrant tympanic FN and inner ear anomalies was significantly (P = .038) associated with a known congenital syndrome (6 patients), including CHARGE syndrome, oculo-auriculo-vertebral spectrum, Pierre-Robin sequences, and Down syndrome. Therefore, an anomalous tympanic FN in conjunction with inner ear anomalies appears to be a biomarker for certain congenital syndromes with hearing loss in the absence of microtia.

Anatomical Features of Intratemporal Course of Facial Nerve and its Variations

Introduction

Facial nerve has the longest and complex course in its bony canal. The anatomical variations make the nerve prone to injury during mastoid surgeries. Having a thorough anatomical knowledge and its variations is must for the surgeons to avoid injury to this vital structure and for the safe surgery. The objective of the study was to describe the anatomical variations of intratemporal portion of facial nerve.

Materials and methods

The study was conducted in the department of otorhinolaryngology in the temporal bone dissection laboratory of a tertiary health care centre. Fifty wet temporal bones were dissected by the same team of surgeons for the duration of one year to study the various anomalies of the intratemporal course of the facial nerve and its relations with the other important middle ear structures.

Results

The mean length of the labyrinth, tympanic and mastoid segment of the facial nerve was 4.1 mm (±0.6 mm), 9.34 mm (±1.12 mm) and 12.8 mm (±1.8 mm), respectively. The mean distance between the horizontal segment and posterior edge of the oval window was 3.1 mm (±1.03 mm). Dehiscence in the tympanic segment was observed in three temporal bones (6%). Two (4%) specimens had bifurcation of the mastoid segment of the facial nerve. In all dissected temporal bones, the chorda tympani travelled in an ascending path.

Conclusion

The most common site for facial nerve anomaly is the tympanic portion. Anomalous conditions that can place the nerve at risk of being injured by the surgeons are highlighted here.

Endoscopic versus microscopic approach in attic cholesteatoma surgery

PURPOSE

Compare the outcomes of primary exclusive endoscopic ear surgery with those of the microscopic ear surgery in a group of patients affected by attic cholesteatoma.

MATERIALS AND METHODS

Eighty patients suffered from attic cholesteatoma. Forty patients surgical treated with endoscopic ear surgery and forty patients surgical treated with microscopic ear surgery.

RESULTS

No statistical differences were found in the parameters analysed (frequency of facial nerve dehiscence, age, disease duration, site of dehiscence) between the endoscopic and microscopic groups indicating a homogeneous selection thus providing a good comparison of the outcomes between the two groups. None of the patients in our survey developed postoperative iatrogenic facial palsy. Graft success rate was 100% in both groups. The overall operation time of endoscopic ear surgery presented a mean value of 87.8min, while in the group of patients treated via microscopic ear surgery a lower mean value of 69.9min was reported. The average healing time was 36.3days for the endoscopic subgroup and 47.8days for the microscopic subgroup.

CONCLUSION

The surgical outcomes of endoscopic ear surgery are comparable to those of the conventional approach in terms postoperative air-conduction, graft success rate and taste sensation. The analysis of postoperative pain and healing times showed better results for EES. The mean operative times of endoscopic ear surgery gradually shortened as the surgeons gained expertise in performing one-hand surgery.

Comparison of Treatment Outcomes Following Either Prefrontal Cortical-only or Dual-site Repetitive Transcranial Magnetic Stimulation in Chronic Tinnitus Patients: A Double-blind Randomized Study

OBJECTIVES

We evaluated treatment outcomes following single-site repetitive transcranial magnetic stimulation (rTMS) in the dorsolateral prefrontal cortex (DLPFC) and dual-site rTMS in the auditory cortex (AC) and DLPFC (AC + FC).

STUDY DESIGN AND PATIENTS

This prospective randomized double-blind trial initially included 19 patients with chronic tinnitus and 17 of these patients received rTMS on the left AC and left DLPFC or only the left DLPFC. The subjects were randomly allocated to either the dual-site rTMS (AC + FC) protocol (Group 1, n = 9) or the singlesite rTMS (DLPFC) protocol (Group 2, n = 8). Group 1 received daily treatments with 2,000 pulses applied to the AC and 1,000 pulses applied to the DLPFC for 4 days (total of 12,000 pulses) and Group 2 received daily treatments with 3,000 pulses applied the DLPFC for 4 days (total of 12,000 pulses).

MAIN OUTCOME MEASURES

The severity of tinnitus was assessed before rTMS treatment using the Tinnitus Handicap Inventory (THI) and the self-rated Visual Analog Scale. These measures were used to determine the awareness, loudness, annoyance, and effects of tinnitus on daily life at 1, 2, 4, and 12 weeks after treatment.

RESULTS

The improvement in THI score was significantly better in Group 1 than in Group 2, even after controlling for the between-group differences in pretreatment THI score. In terms of psychological factors, Group 1 exhibited significant improvements in scores on the State-Trait Anxiety Inventory (STAI) for both state anxiety (STAI-X1) and trait anxiety (STAI-X2) at 12 weeks posttreatment and scores on the Pittsburgh Sleep Quality Index at 4 weeks posttreatment. Group 2 showed an improvement in only the STAI-X2 score at 12 weeks posttreatment.

CONCLUSIONS

The rTMS protocol effectively suppressed tinnitus in the dual-site rTMS (AC+FC) group but not in the single-site rTMS (DLPFC) group. Although recent evidence has shown that non-auditory cortices in the tinnitus network play an important role in the generation of tinnitus, our findings indicate that rTMS on non-auditory cortical sites alone may not be sufficient for treatment. Thus, dual-site rTMS in the AC and DLPFC may be preferable for controlling this condition.

Micro-CT study of the dehiscences of the tympanic segment of the facial canal

PURPOSE

To depict the anatomy of the tympanic segment of the facial canal using a 3D visualization technique, to detect dehiscences, and to evaluate their frequency, location, shape, and size.

METHODS

Research included 36 human temporal bones (18 infant and 18 adult samples) which were scanned using a Nanotom 180N device. The final resolution of the reconstructed object was 18 µm. Obtained micro-CT data were subsequently processed by the volume rendering software.

RESULTS

The micro-CT study allowed for the 3D visualization of the tympanic segment of the facial canal and detects dehiscences in the studied material in both infants and adults. Most of the dehiscences (66.7 %) involved the inferior wall of the tympanic segment in infants as well as in adults, and were located above and backward to the oval window. The most frequent dehiscence shape was elliptic (66.7 % in infants; 50 % in adults). Furthermore, we observed dehiscences of fusiform and trapezoidal shape in infants. Length of the dehiscences in most cases ranged from 0.5 to 1.4 mm (50 % in infants; 75 % in adults).

CONCLUSIONS

Volumetric reconstructions demonstrated the course of the tympanic segment of the facial canal and its relationship with the tympanic cavity. Knowledge about the size and location of any dehiscence within the tympanic segment of the facial canal is necessary due to the surgical significance of this region. If a dehiscence occurs, there is an increased risk of injury to the facial nerve during the operations or spread of inflammation from the middle ear.

Relation between Ossicular Erosion and Destruction of Facial and Lateral Semicircular Canals in Chronic Otitis Media

Introduction  Chronic otitis media can cause multiple middle ear pathogeneses. The surgeon should be aware of relation between ossicular chain erosion and other destructions because of the possibility of complications. Objective  This study aimed to investigate the rates of ossicular erosion in cases of patients with and without facial nerve canal destruction, who had undergone mastoidectomy due to chronic otitis media with or without cholesteatoma. Methods  We retrospectively analyzed three hundred twenty-seven patients who had undergone tympanomastoidectomy between April 2008 and February 2014. We documented the types of mastoidectomy (canal wall up, canal wall down, and radical mastoidectomy), erosion of the malleus, incus and stapes, and the destruction of facial and lateral semi-circular canal. Results  Out of the 327 patients, 147 were women (44.95%) and 180 were men (55.04%) with a mean age 50.8 ± 13 years (range 8-72 years). 245 of the 327 patients (75.22%) had been operated with the diagnosis of chronic otitis media with cholesteatoma. FNCD was present in 62 of the 327 patients (18.96%) and 49 of these 62 (79.03%) patients had chronic otitis media with cholesteatoma. The correlation between the presence of FNCD with LSCC destruction and stapes erosion in chronic otitis media with cholesteatoma is statistically significant ( p  < 0.05). Conclusion  Although incus is the most common of destructed ossicles in chronic otitis media, facial canal destruction is more closely related to stapes erosion.

Facial Nerve Paralysis in Patients With Chronic Ear Infections: Surgical Outcomes and Radiologic Analysis

Objectives

The purpose of this study was to investigate the clinical features, radiologic findings, and treatment outcomes in patients of facial nerve paralysis with chronic ear infections. And we also aimed to evaluate for radiologic sensitivities on facial canal, labyrinth and cranial fossa dehiscences in middle ear cholesteatomas.

Methods

A total of 13 patients were enrolled in this study. Medical records were retrospectively reviewed for clinical features, radiologic findings, surgical findings, and recovery course. In addition, retrospective review of temporal bone computed tomography (CT) and operative records in 254 middle ear cholesteatoma patients were also performed.

Results

Of the 13 patients, eight had cholesteatomas in the middle ear, while two patients exhibited external auditory canal cholesteatomas. Chronic suppurative otitis media, petrous apex cholesteatoma and tuberculous otitis media were also observed in some patients. The prevalence of facial paralysis in middle ear cholesteatoma patients was 3.5%. The most common involved site of the facial nerve was the tympanic segment. Labyrinthine fistulas and destruction of cranial bases were more frequently observed in facial paralysis patients than nonfacial paralysis patients. The radiologic sensitivity for facial canal dehiscence was 91%. The surgical outcomes for facial paralysis were relatively satisfactory in all patients except in two patients who had petrous apex cholesteatoma and requiring conservative management.

Conclusion

Facial paralyses associated with chronic ear infections were observed in more advanced lesions and the surgical outcomes for facial paralysis were relatively satisfactory. Facial canal dehiscences can be anticipated preoperatively with high resolution CTs.

The intra-operative incidence of Fallopian canal dehiscence during surgery for cholesteatoma: a prospective case-control study and review of the literature

OBJECTIVE

To investigate Fallopian canal dehiscence (FCD) during cholesteatoma surgery.

STUDY DESIGN

Prospective case-control study.

PATIENTS

Four hundred and one patients with cholesteatoma and 172 with otosclerosis.

INTERVENTIONS

Therapeutic.

SETTING

District general hospital.

MAIN OUTCOME MEASURES

(i) Intra-operative incidence of FCD during (a) surgery for cholesteatoma versus a homogeneous control group (patients with otosclerosis); (b) revision surgery for cholesteatoma as compared to primary surgery. (ii) Intra-operative incidence of a fistula if FCD is present.

RESULTS

Data were prospectively collected and analysed using chi-square tests. FCD was found in 19% of cases versus 5.2% of controls. Intra-operative incidence of (i) FCD during cholesteatoma surgery versus otosclerosis surgery was statistically very highly significant (P < 0.0001, OR = 5.43); (ii) FCD during revision versus primary cholesteatoma surgery was not statistically significant (P = 0.83); and (iii) encountering a fistula in the presence of FCD during cholesteatoma surgery was statistically very highly significant (P < 0.0001, OR = 6.71).

CONCLUSIONS

A surgeon is more likely to encounter FCD during cholesteatoma surgery than in stapes surgery. If during cholesteatoma surgery FCD is found, then a fistula is also more likely to be present, mainly of the semicircular canal. The incidence of FCD is not increased in revision surgery. These findings are very relevant for any otologist undertaking cholesteatoma surgery.

Differences in clinical characteristics of fallopian canal dehiscence associated with pars flaccida and pars tensa cholesteatomas

This study investigated the difference in clinical characteristics of fallopian canal dehiscence associated with pars flaccida and pars tensa cholesteatomas for the purpose of increasing the preoperative detectability of dehiscence. A total of 189 ears of patients 7-80 years of age (mean 42 years) with pars flaccida cholesteatoma and 63 ears of patients 9-84 years of age (mean 50 years) with pars tensa cholesteatoma were studied. All patients had undergone prior surgical management at our institution from January 2006 to April 2012. The incidence of fallopian canal dehiscence and its location were compared between pars flaccida and pars tensa cholesteatomas. Intraoperative findings of coexistent pathologies, including destruction of the stapes superstructure, labyrinthine fistula, and dural exposure, were compared between the dehiscence and no-dehiscence groups for the two types of cholesteatomas. The incidence of dehiscence was significantly higher in patients with pars tensa cholesteatoma (55.6 %) than in patients with pars flaccida cholesteatoma (26.5 %). Dehiscence located posterior to the cochleariform process occurred slightly more frequently in patients with pars tensa cholesteatoma than in those with pars flaccida cholesteatoma. In patients with pars flaccida cholesteatoma, labyrinthine fistulas and dural exposure were significantly more frequent in the dehiscence group than in the no-dehiscence group. Fallopian canal dehiscence is more frequent in patients with pars tensa cholesteatoma than in those with pars flaccida cholesteatoma. Especially in patients with pars flaccida cholesteatoma, paying special attention to these coexisting pathologies is important to increase preoperative detectability of dehiscence.