1,721,264 research outputs found
Petrous bone cholesteatoma: clinical longitudinal study.
Full text linkAbstract The object of this retrospective study was to describe a series of patients with petrous bone cholesteatomas, paying particular attention to classification, diagnosis, surgical strategy, results, complications and recurrences. Furthermore, the study was designed to evaluate the impact of imaging techniques on an early diagnosis. Topographically, the petrous bone cholesteatomas of the present series were grouped using Sanna’s classification and different surgical approaches were used. High resolution CT and/or MRI were used to follow-up the patients. The case notes of 52 patients with petrous bone cholesteatomas who were referred to our hospital for surgery between 1987 and 2003 were reviewed postoperatively. There were 45 primary cases and 7 recurrences. The facial nerve had been inWltrated and compressed by the cholesteatoma in 18 patients. Fourteen were managed with cable grafts using sural nerve or great auricular nerves. About 26 patients with preoperative grade Ivconfirmed their normal facial function in 23 cases. In the other ten patients, the preoperative facial paralysis was due to compression by the cholesteatoma and its removal provided partial recovery of facial function in four patients. Our study compared two observation periods (1987–1996 and 1997–2003) when the diffusion and the availability of imaging techniques in our national health system had considerably increased. Two important factors emerged: firstly, the number of less extensive surgical approaches was higher in the more recent observation period, proving that cholesteatomas smaller in size had been diagnosed. Secondly, preoperative facial paralysis was less frequent in the same period—falling to 25% of cases of total facial paralysis from the 45.8% of the earlier period practically half as much. The partial paralyses instead increased slightly, demonstrating that otologists have become more sensitive to and pay more attention to this symptom
Self-crimping superelastic nitinol prosthesis and malleostapedotomy: a temporal bone study.
No full textOBJECTIVE:
The aim of this study was to compare the results of application of 2 types of superelastic nitinol prostheses.
STUDY DESIGN:
Temporal bones study with planned data collection.
SETTING:
Tertiary referral center.
SUBJECTS AND METHODS:
Malleostapedotomy was performed in 15 human temporal bones implanting 3 different prostheses: manually crimping polytetrafluoroethylene (MC-PTFE) piston, nitinol self-crimping polytetrafluoroethylene (SC-PTFE) piston, and a modified nitinol self-crimping polytetrafluoroethylene (mSC-PTFE) piston. The first 2 have a diameter of 0.4 mm and length of 7 mm, whereas the mSC-PTFE piston has a diameter of 0.4 mm but a length of 7.75 mm. We evaluated various parameters of prosthesis attachment-that is, the time for implantation of SC and mSC nitinol loop pistons and the MC platinum loop piston, the quality of attachment of the prostheses to the malleus, their positions with respect to the center of the stapes footplate, and the protrusion of the piston into the vestibule.
RESULTS:
The mSC-PTFE superelastic nitinol prosthesis showed a statistically significant difference in mean operation time (mSC vs SC, P < .0001; SC vs MC, P < .0001; mSC vs MC, P < .0001). The protrusion of the piston into the vestibule was highly reproducible in all 3 prostheses.
CONCLUSION:
Because of its greater length, the mSC-PTFE allows for management of the most varied anatomical conditions. At the same time, its self-crimping nature prevents the risk of distortion of the prosthesis by the crimping process and reduces the operation time in combination with standardized bending of the prosthesis shaft
Modified retrolabyrinthine approach with partial labyrinthectomy: Anatomic study
Full text linkThis study was undertaken to evaluate the feasability of the modified retrolabyrinthine approach (traditional retrolabyrinthine approach plus resection of the posterior semicircular canal) to expose the entire fundus of the internal auditory canal (IAC). This approach is advocated by its proponents to manage acoustic neuromas reaching the lateral IAC and with the preservation of hearing as the goal. Little anatomic data directly estimate the limitations of this exposure. Measurements were recorded from 25 cadaver temporal bones dissected with this modified approach. The distances were taken between the porus acousticus (inferior and superior portions), the dome of the jugular bulb, the midportion of the sigmoid sinus, and the fundus of the IAC (inferior and superior portions). All of the measurements were then compared with those of the translabyrithine approach. The current study shows that despite the sacrifice of the posterior semicircular canal, the superior lateral fundus cannot be completely visualized. There is a distance (on average 1.1 mm) that differentiates the superior area of the IAC accessible with translabyrithine and modified retrosigmoid techniques. This value is smaller than that observed in the classic retrosigmoid approach indicating that the modified technique affords a more adequate, even if not ideal, exposure to minimize the risk of recurrence. The modified retrolabyrinthine approach provided an optimal exposure of the inferior half of the IAC. A superior blind area, smaller than that of the traditional retrolabyrinthine technique, cannot be completely approached via this route. We believe that this approach can be considered as an alternative technique in selected cases especially for tumors involving the inferior vestibular nerve
Intra-operative facial nerve monitoring. Its predictive value after skull base surgery
No full textPurpose: Facial nerve monitoring can be used to predict post-operative facial function after skull base surgery. In this study three methods of prediction of facial function were compared. These methods utilize various parameters of the evoked electromyographic monitoring. Material and methods: Twenty-three patients who underwent surgery for skull base diseases were retrospectively reviewed. Amplitude of ongoing electromyographic activity, stimulation current thresholds and amplitude of evoked response were analysed. The predictive value of the three methods was correlated with post-operative facial nerve function. Results: The method that used only the stimulation thresholds predicted the final post-operative facial function in 86.9 per cent of the patients. The second employed a mathematical ratio which combined the amplitude of evoked response and the stimulation current thresholds and confirmed the prediction of the facial function in 91.3 per cent of the patients. The last method does not consider the stimulation thresholds greater than 0.05 mA and failed to predict the final VIIth nerve function in patients in whom the stimulation was greater than 0.05 mA. Conclusion: Analysis of prognostic value demonstrates that the first two methods had the smaller degree of variation showing the better sensitivity
Response to letter to the editor: comment on usher's syndrome: evaluation of the vestibular system with cervical and ocular vestibular evoked myogenic potentials and the video head impulse test
No full textIn our clinical study, a vestibular protocol to evaluate patients affected by Usher’s syndrome was designed to investigate their otolith and ampullary functions. All patients were selected by the ophthalmologists who adopted various parameters (severity of hearing loss,
the presence of vertigo, the severity and the age of visual loss onset). The main purpose of our study was to evaluate the presence of ‘‘latent’’ vestibular damage in patients clinically classified as USH2, who theoretically should not have any damage to the vestibular receptors. Although we were aware of the importance of the genetic screening technique, as claimed in the ‘‘Discussion’’ section (1), genetic studies to analyze the type of genetic mutation present for better characterizing USH I or USH II patients were not performed.
Genetic analysis of allelic mutation related to the Usher syndrome type and subclass (MYO7A, CDH23, PCDH15, USH1C, USH1G, USH2A, ADGRV1/GPR98, DFNB31, CLRN1, PDZD7) is actually under way for all patients enrolled in the study (2,3). These genetic results will be compared with the vestibular tests to clarify whether the clinical classification adopted confirms the results of the study
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