Hearing preservation in acoustic neuroma surgery: importance of adhesion between the cochlear nerve and the tumor

2002 ◽  
Vol 97 (2) ◽  
pp. 337-340 ◽  
Author(s):  
Takuzou Moriyama ◽  
Takanori Fukushima ◽  
Katsuyuki Asaoka ◽  
Pierre-Hugues Roche ◽  
David M. Barrs ◽  
...  
Keyword(s):  
Acoustic Neuroma ◽  
Hearing Preservation ◽  
Cochlear Nerve ◽  
Significant Prognostic Factor ◽  
Speech Discrimination ◽  
Middle Fossa ◽  
Content Type ◽  
Middle Fossa Approach ◽  
Acoustic Neuromas ◽  
Fine Print

Object. To evaluate the possible prognostic factors for hearing preservation, the authors retrospectively reviewed the results of 30 consecutive acoustic neuroma operations in which hearing preservation was attempted, in a total series of 63 acoustic neuromas. Methods. Intracanalicular tumors or those that extended less than 3 mm outside the porus acusticus (10 cases) were resected via the middle fossa approach. The retrosigmoid approach was used for tumors exceeding the limits for the middle fossa approach (20 cases). Overall, hearing was preserved (pure tone average ≤ 50 dB and speech discrimination score ≥ 50%) in 21 patients (70%). There were 11 patients with severe adhesion between the cochlear nerve and tumor capsule, and 19 without. Hearing was preserved postoperatively in only two (18.2%) of 11 patients with severe adhesion, whereas all 19 without severe adhesion had hearing preservation. Conclusions. The presence or absence of severe adhesion in the interface between the cochlear nerve and the tumor might be the most significant prognostic factor for hearing preservation postsurgery.

Preservation of hearing in patients undergoing excision of acoustic neuromas and other cerebellopontine angle tumors

1985 ◽  
Vol 63 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Charles H. Tator ◽  
Julian M. Nedzelski
Keyword(s):  
Tumor Size ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Hearing Preservation ◽  
Cochlear Nerve ◽  
Consecutive Series ◽  
Speech Discrimination ◽  
Content Type ◽  
Acoustic Neuromas ◽  
Fine Print

✓ Microsurgical techniques have made it possible to identify and preserve the cochlear nerve from its origin at the brain stem and along its course through the internal auditory canal in patients undergoing removal of small or medium-sized acoustic neuromas or other cerebellopontine angle (CPA) tumors. In a consecutive series of 100 patients with such tumors operated on between 1975 and 1981, an attempt was made to preserve the cochlear nerve in 23. The decision to attempt to preserve hearing was based on tumor size and the degree of associated hearing loss. In cases of unilateral acoustic neuroma, the criteria for attempted preservation of hearing were tumor size (2.5 cm or less), speech reception threshold (50 dB or less), and speech discrimination score (60% or greater). In patients with bilateral acoustic neuromas or tumors of other types, the size and hearing criteria were significantly broadened. All patients were operated on through a suboccipital approach. Hearing was preserved postoperatively in six (31.6%) of the 19 patients with unilateral acoustic neuromas, although the cochlear nerve was preserved in 16. Of the six patients with postoperative hearing, three retained excellent hearing, and the other three had only sound awareness and poor discrimination. Hearing was preserved in three cases with other CPA tumors, including an epidermoid cyst and small petrous meningiomas in the internal auditory canal. Of the two cases with bilateral tumors, hearing was preserved in one. Of the 23 patients in whom hearing preservation was attempted, nine (39.1%) had some postoperative hearing, which in six was equal to or better than the preoperative level. Thus, it is worthwhile to attempt hearing preservation in selected patients with CPA tumors.

Preservation of hearing in surgery for acoustic neuromas

1993 ◽  
Vol 78 (6) ◽  
pp. 864-870 ◽  
Author(s):  
Michael E. Glasscock ◽  
James W. Hays ◽  
Lloyd B. Minor ◽  
David S. Haynes ◽  
Vincent N. Carrasco
Keyword(s):  
Hearing Preservation ◽  
Middle Cranial Fossa ◽  
Senior Author ◽  
Speech Discrimination ◽  
Content Type ◽  
Auditory Evoked Response ◽  
Surgical Access ◽  
Acoustic Neuromas ◽  
Cranial Fossa ◽  
Fine Print

✓Preservation of hearing was attempted in 161 cases of histologically confirmed acoustic neuroma removed by the senior author between January 1, 1970, and September 30, 1991. There were 136 patients with unilateral tumors: 22 patients had bilateral tumors (neurofibromatosis 2) and underwent a total of 25 procedures. Hearing was initially preserved in 35% of patients with unilateral tumors and in 44% of those with bilateral tumors. Results are reported in terms of pre- and postoperative pure tone average and speech discrimination scores. Surgical access to the tumor was obtained via middle cranial fossa and suboccipital approaches. The latter has been used more often over the past 5 years because of a lower associated incidence of transient facial paresis. Persistent postoperative headaches have been the most common complication following the suboccipital approach. The results of preoperative brain-stem auditory evoked response (BAER) studies were useful in predicting the outcome of hearing preservation attempts. Patients with intact BAER waveform morphology and normal or delayed latencies had a higher probability of hearing preservation in comparison to those with abnormal preoperative BAER morphology.

scholarly journals Middle cranial fossa approach for acoustic neuroma

2021 ◽  
Vol 5 (2) ◽  
pp. V12
Author(s):  
Paul W. Gidley ◽  
Joel Z. Passer ◽  
Joshua C. Page ◽  
Franco DeMonte
Keyword(s):  
Acoustic Neuroma ◽  
Hearing Preservation ◽  
Middle Cranial Fossa ◽  
Middle Fossa ◽  
Surgical Indications ◽  
Total Resection ◽  
Technical Aspects ◽  
Middle Fossa Approach ◽  
Acoustic Neuromas ◽  
Cranial Fossa

The middle fossa approach for the resection of small acoustic neuromas is a viable, but underutilized treatment modality with the goal of hearing preservation. The authors aim to demonstrate this approach and its nuances through this video presentation. A 38-year-old man presented with an incidentally discovered small, intracanalicular acoustic neuroma that was initially observed, but growth was noted. The patient had good hearing, and therefore a hearing preservation approach was offered. A gross-total resection was achieved, and the patient maintained good hearing postoperatively. This video demonstrates relevant anatomy, surgical indications, technical aspects of resection, including reconstruction, and postoperative outcomes. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21124

Cochlear implantation in an intralabyrinthine acoustic neuroma patient after resection of an intracanalicular tumour

1996 ◽  
Vol 110 (6) ◽  
pp. 570-573 ◽  
Author(s):  
Tetsuya Tono ◽  
Yasuaki Ushisako ◽  
Tamotsu Morimitsu
Keyword(s):  
Cochlear Implant ◽  
Acoustic Neuroma ◽  
Cochlear Implantation ◽  
Therapeutic Strategy ◽  
Cochlear Nerve ◽  
Middle Fossa ◽  
Middle Fossa Approach ◽  
Tumour Removal ◽  
Bilateral Acoustic Neuroma

AbstractThis case study describes a therapeutic strategy using a cochlear implant for a bilateral acoustic neuroma deafened patient. The cochlear nerve had previously been sacrificed on one side during tumour removal, but on the remaining side a functioning cochlear nerve was assessed by electric promontory stimulation in spite of a neuroma extending into the vestibular labyrinth. The patient was successfully stimulated with a Nucleus 22- channel implant after removal of the intracanalicular portion of the neuroma via a middle fossa approach.

Vasoactive treatment for hearing preservation in acoustic neuroma surgery

2001 ◽  
Vol 95 (5) ◽  
pp. 771-777 ◽  
Author(s):  
Christian Strauss ◽  
Barbara Bischoff ◽  
Mandana Neu ◽  
Michael Berg ◽  
Rudolf Fahlbusch ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Acoustic Neuroma ◽  
Auditory Evoked Potentials ◽  
Consecutive Series ◽  
Hearing Level ◽  
Pathophysiological Mechanism ◽  
Content Type ◽  
Acoustic Neuromas ◽  
Vasoactive Medication ◽  
Fine Print

Object. Delayed hearing loss following surgery for acoustic neuroma indicates anatomical and functional preservation of the cochlear nerve and implies that a pathophysiological mechanism is initiated during surgery and continues thereafter. Intraoperative brainstem auditory evoked potentials (BAEPs) typically demonstrate gradual reversible loss of components in these patients. Methods. Based on this BAEP pattern, a consecutive series of 41 patients with unilateral acoustic neuromas was recruited into a prospective randomized study to investigate hearing outcomes following the natural postoperative course and recuperation after vasoactive medication. Both groups were comparable in patient age, tumor size, and preoperative hearing level. Twenty patients did not receive postoperative medical treatment. In 70% of these patients anacusis was documented and in 30% hearing was preserved. Twenty-one patients were treated with hydroxyethyl starch and nimodipine for an average of 9 days. In 66.6% of these patients hearing was preserved and in 33.3% anacusis occurred. Conclusions. These results are statistically significant (p < 0.05, χ2 = 5.51) and provide evidence that these surgically treated patients suffer from a disturbed microcirculation that causes delayed hearing loss following removal of acoustic neuromas.

Results of acoustic neuroma radiosurgery: an analysis of 5 years' experience using current methods

2001 ◽  
Vol 94 (1) ◽  
pp. 1-6 ◽  
Author(s):  
John C. Flickinger ◽  
Douglas Kondziolka ◽  
Ajay Niranjan ◽  
L. Dade Lunsford
Keyword(s):  
Acoustic Neuroma ◽  
Gamma Knife Radiosurgery ◽  
Current Treatment ◽  
High Rate ◽  
Tumor Control ◽  
Hearing Level ◽  
Speech Discrimination ◽  
Facial Weakness ◽  
Content Type ◽  
Fine Print

Object. The goal of this study was to define tumor control and complications of radiosurgery encountered using current treatment methods for the initial management of patients with unilateral acoustic neuroma. Methods. One hundred ninety patients with previously untreated unilateral acoustic neuromas (vestibular schwannomas) underwent gamma knife radiosurgery between 1992 and 1997. The median follow-up period in these patients was 30 months (maximum 85 months). The marginal radiation doses were 11 to 18 Gy (median 13 Gy), the maximum doses were 22 to 36 Gy (median 26 Gy), and the treatment volumes were 0.1 to 33 cm3 (median 2.7 cm3). The actuarial 5-year clinical tumor-control rate (no requirement for surgical intervention) for the entire series was 97.1 ± 1.9%. Five-year actuarial rates for any new facial weakness, facial numbness, hearing-level preservation, and preservation of testable speech discrimination were 1.1 ± 0.8%, 2.6 ± 1.2%, 71 ± 4.7%, and 91 ± 2.6%, respectively. Facial weakness did not develop in any patient who received a marginal dose of less than 15 Gy (163 patients). Hearing levels improved in 10 (7%) of 141 patients who exhibited decreased hearing (Gardner-Robertson Classes II–V) before undergoing radiosurgery. According to multivariate analysis, increasing marginal dose correlated with increased development of facial weakness (p = 0.0342) and decreased preservation of testable speech discrimination (p = 0.0122). Conclusions. Radiosurgery for acoustic neuroma performed using current procedures is associated with a continued high rate of tumor control and lower rates of posttreatment morbidity than those published in earlier reports.

Vascularized temporalis muscle flap for the treatment of otorrhea

2003 ◽  
Vol 98 (5) ◽  
pp. 1128-1132 ◽  
Author(s):  
Gabriel C. Tender ◽  
Scott Kutz ◽  
Deepak Awasthi ◽  
Peter Rigby
Keyword(s):  
Intracranial Pressure ◽  
Muscle Flap ◽  
Middle Fossa ◽  
Temporalis Muscle ◽  
Increased Intracranial Pressure ◽  
Content Type ◽  
Middle Fossa Approach ◽  
Medial Side ◽  
Temporalis Muscle Flap ◽  
Fine Print

✓ The surgical treatment for cerebral spinal fluid (CSF) fistulas provides closure of the bone and dural defects and prevents the recurrence of brain herniation and CSF fistula. The two main approaches used are the transmastoid and middle fossa ones. The authors review the results of performing a modified middle fossa approach with a vascularized temporalis muscle flap to create a barrier between the repaired dural and bone defects. Fifteen consecutive cases of CSF fistulas treated at the authors' institution were retrospectively reviewed. All patients presented with otorrhea. Eleven patients had previously undergone ear surgery. A middle fossa approach was followed in all cases. The authors used a thin but watertight and vascularly preserved temporalis muscle flap that had been dissected from the medial side of the temporalis muscle and was laid intracranially on the floor of the middle fossa, between the repaired dura mater and petrous bone. The median follow-up period was 2.5 years. None of the patients experienced recurrence of otorrhea or meningitis. There was no complication related to the intracranial temporalis muscle flap (for example, seizures or increased intracranial pressure caused by muscle swelling). One patient developed hydrocephalus, which resolved after the placement of a ventriculoperitoneal shunt 2 months later. The thin, vascularized muscle flap created an excellent barrier against the recurrence of CSF fistulas and also avoided the risk of increased intracranial pressure caused by muscle swelling. This technique is particularly useful in refractory cases.

Hearing conservation in acoustic neuroma surgery via the posterior fossa

1990 ◽  
Vol 104 (6) ◽  
pp. 463-467 ◽  
Author(s):  
D. L. Baldwin ◽  
T. T. King ◽  
A. W. Morrisin
Keyword(s):  
Posterior Fossa ◽  
Acoustic Neuroma ◽  
Hearing Preservation ◽  
Cochlear Nerve ◽  
Surgical Removal ◽  
Speech Discrimination ◽  
Hearing Conservation ◽  
Operative Morbidity ◽  
Number Of Patients ◽  
Principle Objective

AbstractAn increasing number of patients with an acoustic neuroma present with useful hearing in the tumour ear. Surgical removal of these tumours via the posterior fossa route may enable preservation of the cochlear nerve and otic capsule without increasing the morbidity to the facial nerve. The results of treating 51 cases of acoustic neuroma via the posterior fossa is presented. Forty four tumours measured less than 20 mm in diameter in the cerebellopontine angle and surgery was undertaken with hearing preservation as a principle objective. In 26 cases, the cochlear nerve was preserved anatomically and post-operative hearing at levels better than mean pure tone threshold of 50 dB or 50 per cent speech discrimination was recorded in 14 patients. The preservation of hearing represents a worthwhile surgical goal in selected patients with an acoustic neuroma without increasing the operative morbidity.

Extended middle fossa approach: quantitative analysis of petroclival exposure and surgical freedom as a function of successive temporal bone removal by using frameless stereotaxy

2004 ◽  
Vol 100 (4) ◽  
pp. 695-699 ◽  
Author(s):  
Frank P. K. Hsu ◽  
Gregory J. Anderson ◽  
Aclan Dogan ◽  
Joseph Finizio ◽  
Akio Noguchi ◽  
...  
Keyword(s):  
Temporal Bone ◽  
High Speed ◽  
Internal Auditory Canal ◽  
Frameless Stereotaxy ◽  
Middle Fossa ◽  
Content Type ◽  
Middle Fossa Approach ◽  
Bone Removal ◽  
Stereotactic System ◽  
Fine Print

Object. Conventional wisdom regarding skull base surgery says that more extensive bone removal equals greater exposure. Few researchers have quantitatively examined this assertion, however. In this study the authors used a frameless stereotactic system to measure quantitatively the area of petroclival exposure and surgical freedom for manipulation of instruments with successive steps of temporal bone removal. Methods. With the aid of high-power magnification and a high-speed drill, 12 cadaveric specimens were dissected in four predetermined, successive bone removal steps: 1) removal of the Kawase triangle; 2) removal of the Glasscock triangle; 3) removal of the cochlea together with skeletonization of the anterior internal auditory canal; and 4) inferior displacement of the zygoma. Step 1 offered 62 ± 43 mm2 of exposed petroclival area, with 84 ± 69 mm2 of surgical freedom; Step 2, 61 ± 22 and 76 ± 58 mm2; Step 3, 128 ± 47 and 109 ± 87 mm2; and Step 4, 135 ± 38 and 102 ± 69 mm2, respectively. Conclusions. The middle fossa approach provided a means surgically to expose the petroclival area. When examined quantitatively by using a frameless stereotactic device, the authors determined that the removal of the cochlea and skeletonization of the anterior internal auditory canal (Step 3) provided the most significant increase in both exposure and surgical freedom. Removal of the zygoma improved neither exposure nor surgical freedom.

Trigeminal schwannomas: removal of dumbbell-shaped tumors through the expanded Meckel cave and outcomes of cranial nerve function

2002 ◽  
Vol 96 (3) ◽  
pp. 453-463 ◽  
Author(s):  
Ossama Al-Mefty ◽  
Samer Ayoubi ◽  
Esam Gaber
Keyword(s):  
Cranial Nerve ◽  
Nerve Function ◽  
Middle Fossa ◽  
Total Removal ◽  
Content Type ◽  
Middle Fossa Approach ◽  
Cranial Nerve Function ◽  
Nerve Paresis ◽  
Abducent Nerve ◽  
Fine Print

Object. As in patients with vestibular schwannomas, advances in surgical procedures have markedly improved outcomes in patients with trigeminal schwannomas. In this article the authors address the function of cranial nerves in a series of patients with trigeminal schwannomas that were treated with gross-total surgical removal. The authors emphasize a technique they use to remove a dumbbell-shaped tumor through the expanded Meckel cave, and discuss the advantage of the extradural zygomatic middle fossa approach for total removal of tumor and preservation or improvement of cranial nerve function. Methods. Within an 11-year period (1989–2000), 25 patients (14 female and 11 male patients with a mean age of 44.4 years) with benign trigeminal schwannomas were surgically treated by the senior author (O.A.) with the aim of total removal of the tumor. Three patients had undergone previous surgery elsewhere. Trigeminal nerve dysfunction was present in all but two patients. Abducent nerve paresis was present in 40%. The approach in each patient was selected according to the location and size of the lesion. Nineteen tumors were dumbbell shaped and extended into both middle and posterior fossae. All 25 tumors involved the cavernous sinus. The zygomatic middle fossa approach was particularly useful and was used in 14 patients. The mean follow-up period was 33.12 months. In patients who had not undergone previous surgery, the preoperative trigeminal sensory deficit improved in 44%, facial pain decreased in 73%, and trigeminal motor deficit improved in 80%. Among patients with preoperative abducent nerve paresis, recovery was attained in 63%. Three patients (12%) experienced a persistent new or worse cranial nerve function postoperatively. Fifth nerve sensory deficit persisted in one of these patients, sensory and motor dysfunction in another, and motor trigeminal weakness in the third patient. In all patients a good surgical outcome was achieved. One patient died 2 years after treatment from an unrelated cause. In three patients the tumors recurred after an average of 22.3 months. Conclusions. Preservation or improvement of cranial nerve function can be achieved through total removal of a trigeminal schwannoma, and skull base approaches are better suited to achieving this goal. The zygomatic middle fossa approach is particularly helpful and safe. It allows extradural tumor removal from the cavernous sinus, the infratemporal fossa, and the posterior fossa through the expanded Meckel cave.

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