Object To explore the procedures in per-operative harvesting and management of fresh human cochlear specimens for research. Methods During trans-cochlear surgery to remove large petro-clival meningiomas causing life-t...Object To explore the procedures in per-operative harvesting and management of fresh human cochlear specimens for research. Methods During trans-cochlear surgery to remove large petro-clival meningiomas causing life-threatening compression on the brainstem, cochleae are normally destroyed and drilled away in order to reach the apical petrous and clivus region. Instead the cochlea can be dissected out after ethical per-mission was obtained from the local ethical committee (EPN) and allowance gained from the patients. Sur-gery is performed by a team consisting of oto-and neurosurgeons as a two-day procedure with total petro-sectomy in combination with an inferior re-routing of the facial nerve. Fixation of the cochleae was done in the operating room as soon as the specimens had been separated from the temporal bones. Decalcification began after hours’to overnight’s fixation for 4 weeks. Sectioning parallel to the modiolus (mid-modiolus) was performed with a cryostat microtome. The sections were subjected to immunofluorescence (IF). Results Using freshly prepared 4%paraformaldehyde (PFD) solution, adequate fixation of fine inner ear structures was achieved with hours’immersion of the cochlear specimens. Decalcification in 6.2% ethylene di-amine-tetracetic acid (EDTA) solution for 4 weeks yielded a thoroughly decalcified cochlea. Experiences in processing 14 human cochleae and analysing main landmarks in five human inner ear plastic/silicone casts showed that the oval window/stapes footplate are backward tilted, at an angle about 15 degrees, from the plane perpendicular to the modiolar axis. The distance from the modiolar apex to the anterior border of the oval window/footplate in these inner ear casts measured between 4 and 5 mm. High quality IF staining was obtained. Conclusion Surgically obtained human cochlear specimen, when properly processed, contains ide-ally preserved antigenicity for immunohistochemical study. Adequate orientation during sectioning helps ob-tain optimal mid-modiolar sections showing fine structures of the cochlea.展开更多
Stapes surgery for otosclerosis has been proved to be a very satisfying procedure. However, the condition is difficult for the patients with no or little hearing gain after surgery and for those who had sudden or grad...Stapes surgery for otosclerosis has been proved to be a very satisfying procedure. However, the condition is difficult for the patients with no or little hearing gain after surgery and for those who had sudden or gradual hearing loss after a successful air-bone gap closure in the follow-up period. The issue of re-exploring the middle ear is challenging. A general review of this subject from several points of view remains lacking. In this study, articles related with the revision surgery for otosclerosis have been reviewed after a Pub Med research and common and/or contradictory points were documented. The aim of this study is to give an insight to diagnostic and therapeutic approaches forthe clinicians in patients who need a revision surgery. In conclusion, prosthesis problems, loose prosthesis in stapedotomy and migrated prosthesis in stapedectomy are the most common causes for revision surgery. Most important indicators which effect better hearing outcome following revision surgery are those ears with the presence of incus, with no obliteration of oval window, with small fenestra stapedotomy and the experience of surgeon. The risk of neurosensorial hearing loss in revision cases is not high but the hearing gain is limited as compared to primary cases. The rate of 10 d B air-bone gap closure is around 60%-70% at most and even less promising results have been reported. Patient's demands and expectations have to be clarified in a realistic way.展开更多
基金supported by ALF grants from the Uppsala University Hospital and Uppsala Universitythe Foundation"Tysta Skolan"+1 种基金the Sellander Foundationthe Swedish Deafness Foundation(HRF)
文摘Object To explore the procedures in per-operative harvesting and management of fresh human cochlear specimens for research. Methods During trans-cochlear surgery to remove large petro-clival meningiomas causing life-threatening compression on the brainstem, cochleae are normally destroyed and drilled away in order to reach the apical petrous and clivus region. Instead the cochlea can be dissected out after ethical per-mission was obtained from the local ethical committee (EPN) and allowance gained from the patients. Sur-gery is performed by a team consisting of oto-and neurosurgeons as a two-day procedure with total petro-sectomy in combination with an inferior re-routing of the facial nerve. Fixation of the cochleae was done in the operating room as soon as the specimens had been separated from the temporal bones. Decalcification began after hours’to overnight’s fixation for 4 weeks. Sectioning parallel to the modiolus (mid-modiolus) was performed with a cryostat microtome. The sections were subjected to immunofluorescence (IF). Results Using freshly prepared 4%paraformaldehyde (PFD) solution, adequate fixation of fine inner ear structures was achieved with hours’immersion of the cochlear specimens. Decalcification in 6.2% ethylene di-amine-tetracetic acid (EDTA) solution for 4 weeks yielded a thoroughly decalcified cochlea. Experiences in processing 14 human cochleae and analysing main landmarks in five human inner ear plastic/silicone casts showed that the oval window/stapes footplate are backward tilted, at an angle about 15 degrees, from the plane perpendicular to the modiolar axis. The distance from the modiolar apex to the anterior border of the oval window/footplate in these inner ear casts measured between 4 and 5 mm. High quality IF staining was obtained. Conclusion Surgically obtained human cochlear specimen, when properly processed, contains ide-ally preserved antigenicity for immunohistochemical study. Adequate orientation during sectioning helps ob-tain optimal mid-modiolar sections showing fine structures of the cochlea.
文摘Stapes surgery for otosclerosis has been proved to be a very satisfying procedure. However, the condition is difficult for the patients with no or little hearing gain after surgery and for those who had sudden or gradual hearing loss after a successful air-bone gap closure in the follow-up period. The issue of re-exploring the middle ear is challenging. A general review of this subject from several points of view remains lacking. In this study, articles related with the revision surgery for otosclerosis have been reviewed after a Pub Med research and common and/or contradictory points were documented. The aim of this study is to give an insight to diagnostic and therapeutic approaches forthe clinicians in patients who need a revision surgery. In conclusion, prosthesis problems, loose prosthesis in stapedotomy and migrated prosthesis in stapedectomy are the most common causes for revision surgery. Most important indicators which effect better hearing outcome following revision surgery are those ears with the presence of incus, with no obliteration of oval window, with small fenestra stapedotomy and the experience of surgeon. The risk of neurosensorial hearing loss in revision cases is not high but the hearing gain is limited as compared to primary cases. The rate of 10 d B air-bone gap closure is around 60%-70% at most and even less promising results have been reported. Patient's demands and expectations have to be clarified in a realistic way.
