Anatomical studies of the posterior petrous apex with regard to hearing preservation in acoustic neuroma removal

Domb, George H.; Chole, Richard A.

doi:10.1288/00005537-198011000-00003

Cited by 77 publications

(32 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In a left lateral position, the head fixed in a clamp in each animal a right lateral craniectomy of the posterior fossa was performed. Care was taken not to retract the cerebellum or to open the labyrinth, because both factors might disturb the BAEPs [9,[32][33][34]. The pre-operative BAEPs were used as the standard measurement.…”

Section: Methodsmentioning

confidence: 99%

Influence of blood supply, thermal and mechanical traumata on hearing function in an animal model

Braun

Richter

1996

Acta neurochir

View full text Add to dashboard Cite

Even with modern neurosurgical techniques preservation of functional hearing in acoustic neurinoma surgery is still impossible in a large number of cases. Due to the necessity of averaging the brainstem auditory evoked potentials (BAEP) this monitoring is not a real time measurement. Therefore the surgeon cannot be sure which manipulation during the tumour dissection has caused the loss of the BAEPs. The direct monitoring of the cochlear nerve (CNAP) may warn the surgeon earlier. But it is not able to explain, which manipulation has caused the worsening of the potentials. A loss of the waves after coagulation of a vessel next to the cochlear nerve may be the result of the heat or of the disturbance of the blood supply. Potentially harmful to cochlear nerve function may be the interruption of inner ear blood supply, thermal or mechanical traumata. Experimental studies are rare to nonexistent. We therefore tested selectively each trauma for its influence on the BAEPs in an animal model. In New Zealand rabbits a lateral craniectomy of the posterior fossa was performed. Care was taken not to retract the cerebellum or to open the inner ear system, because both factors might disturb the BAEPs. Each step of the operation was followed by BAEP recording. After reaching the internal auditory canal, the cerebellopontine angle of 6 animals was exposed to heated water with definitive increasing temperature. The BAEPs did not react significantly until 71 degrees C was reached and protein coagulation started. In the second group, the internal auditory artery of 6 rabbits was compressed with a microdissector for 3 minutes. Subsequently the BAEPs disappeared in all animals. In the last group a constant pressure of 10 g was applied to 6 cochlear nerves for 1 minute consistently causing the loss of the BAEPs. The results are statistically significant (p = 0.03). We therefore concluded that the blood supply of the inner ear is of the upmost importance for cochlear nerve function. Mechanical manipulation should be minimized whereas thermal traumatization of the nerve is only critical when the nerve itself is coagulated.

show abstract

Section: Methodsmentioning

confidence: 99%

Influence of blood supply, thermal and mechanical traumata on hearing function in an animal model

Braun

Richter

1996

Acta neurochir

View full text Add to dashboard Cite

show abstract

“…Some anatomical and radiological studies suggested the impossibility of exposing the fundus of the IAC without violating the semicircular canals, the vestibule or the endolymphatic sac 23,34 . A study recommends leaving about 32% of the lateral portion of the IAC without manipulation to avoid compromising the labyrinth structures 25 .…”

Section: Discussionmentioning

confidence: 99%

Surgical exposure of the internal auditory canal through the retrosigmoid approach with semicircular canals anatomical preservation

Leal

Silva

Ramina³

2015

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

Objective Evaluate the feasibility of an adequate exposure with anatomical preservation of labyrinth structures through retrosigmoid transmeatal approach (RSA) in surgeries for resection of acoustic neuromas/vestibular schwannomas (VS). Method Thirty patients underwent surgical resection and were preoperatively evaluated with fine slice high definition CT scans and 3D-MRI volumetric reconstructions. Extension of internal auditory canal (IAC) opening during surgery was measured using 3 mm right-angle calibrated hook and neuronavigation parameters. Postoperatively, the extension of IAC opening and integrity of the labyrinth were confirmed through preoperatively images procedures. Results The preoperative length of IACs varied between 7.8 and 12.0 mm (mean 9.3 mm, SD 0.98, 95%CI 8.9 to 9.6, and median 9.0 mm). Postoperative images demonstrated adequate opening of the IAC and semicircular channels integrity. Conclusion A complete drilling of the posterior wall of IAC through the RSA is feasible and allows direct visualization of the IAC-fundus without damaging the semicircular canals.

show abstract

“…Já nos acessos suboccipitais, esta parte obscura varia de 2mm 16,17 até zero 18,19 , conforme a via de acesso aproxima-se da linha sagital mediana do crânio. Entretanto, requer-se uma progressiva retração do cerebelo e cérebro nestes acessos.…”

Section: Discussionunclassified

Endoscopia do meato acústico interno pelo acesso retrolabiríntico

Cahali

Neto

et al. 2004

Rev. Bras. Otorrinolaringol.

View full text Add to dashboard Cite

O acesso direto à região do ângulo pontocerebelar pela via retrolabiríntica é seguro, entretanto, não permite a visão direta de todo o meato acústico interno (MAI) pela otomicroscopia. Os endoscópios podem ser utilizados na exploração do MAI por esta via. Objetivo: Nosso objetivo é avaliar a capacidade de inspeção do MAI com endoscópios de diferentes angulações. The retrolabyrinthine approach is a safe route to the cerebellopontine angle, which allows preservation of hearing and facial nerve function. However, it doesn't allow a straight view of the whole internal auditory canal (IAC) with the operating microscope. The endoscopes may be used to assess the IAC during retrolabyrinthine approaches. Aim:The objective of this study is to evaluate the capabilities of different angled endoscopes in assessing the IAC. o endoscope was significantly better than the others in the evaluation of the IAC and it should be considered the optic of choice in the assessment of the IAC during retrolabyrinthine approaches.Palavras-chave: ouvido interno, endoscopia, microscopia.

show abstract

Anatomical studies of the posterior petrous apex with regard to hearing preservation in acoustic neuroma removal

Cited by 77 publications

References 1 publication

Influence of blood supply, thermal and mechanical traumata on hearing function in an animal model

Influence of blood supply, thermal and mechanical traumata on hearing function in an animal model

Surgical exposure of the internal auditory canal through the retrosigmoid approach with semicircular canals anatomical preservation

Endoscopia do meato acústico interno pelo acesso retrolabiríntico

Contact Info

Product

Resources

About