Acoustic neuroma surgery: Difference between revisions
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==Surgery== | ==Surgery== | ||
[[Surgery]] is the mainstay of treatment for acoustic neuroma. Selection of a particular approach is based on several factors, including the size and location of the tumor and whether or not preservation of hearing is a goal. There are three | [[Surgery]] is the mainstay of treatment for acoustic neuroma. Selection of a particular approach is based on several factors, including the size and location of the tumor and whether or not preservation of hearing is a goal. There are three standard surgical approaches for the excision of an acoustic neuroma: | ||
* Translabyrinthine | * Translabyrinthine approach | ||
* Retromastoid suboccipital | * Retromastoid suboccipital approach | ||
* Middle fossa | * Middle fossa approach | ||
===Microsurgery=== | ===Microsurgery=== |
Revision as of 16:57, 11 January 2019
Acoustic neuroma Microchapters | |
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Acoustic neuroma surgery On the Web | |
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Risk calculators and risk factors for Acoustic neuroma surgery | |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Simrat Sarai, M.D. [2]
Overview
Surgery is the mainstay of treatment for acoustic neuroma. Patient with age under 65 years and/or medium to large-grade tumors and/or significant hearing loss, and/or higher headache severity scores will have more satisfying outcomes from surgery in comparison with observation. There are three main surgical approaches for the removal of an acoustic neuroma: translabyrinthine, retrosigmoid or sub-occipital, and middle fossa. Selection of a particular approach is based on several factors, including the size and location of the tumor and whether or not preservation of hearing is a goal.
Indications
Indications for surgery for acoustic neuroma include:[1][2][3]
- Age < 65 years old
- Moderately large to large tumor
- Growing tumors
- Significant hearing loss
- Higher headache severity scores
Surgery
Surgery is the mainstay of treatment for acoustic neuroma. Selection of a particular approach is based on several factors, including the size and location of the tumor and whether or not preservation of hearing is a goal. There are three standard surgical approaches for the excision of an acoustic neuroma:
- Translabyrinthine approach
- Retromastoid suboccipital approach
- Middle fossa approach
Microsurgery
Microsurgical tumor removal can be done at one of three levels: subtotal removal, near total removal or total tumor removal. Subtotal removal is indicated when anything further risks life or neurological function. In these cases the residual tumor should be followed for risk of growth (approximately 35%). If the residual grows further, treatment will likely be required. Periodic MRI studies are important to follow the potential growth rate of any tumor. Near total tumor removal is used by experienced centers when small areas of the tumor are so adherent to the facial nerve that total removal would result in facial weakness. The piece left is generally less than 1% of the original and poses a risk of regrowth of approximately 3%. Periodic MRI studies are important to follow the potential growth rate of any tumor. Many tumors can be entirely removed by surgery. Microsurgical techniques and instruments, along with the operating microscope, have greatly reduced the surgical risks of total tumor removal. Preservation of the facial nerve to prevent permanent facial paralysis is the primary task for the experienced acoustic neuroma surgeon. Preservation of hearing is an important goal for patients who present with functional hearing.
Translabyrinthine approach
The translabyrinthine approach can be preferred for acoustic tumors larger than 3 cm and for smaller tumors when hearing preservation is not considered. [4]
Retrosigmoid/sub-occipital approach
The incision for this approach is located in a slightly different location. This approach creates an opening in the skull behind the mastoid part of the ear, near the back of the head on the side of the tumor. The surgeon exposes the tumor from its posterior (back) surface, thereby getting a very good view of the tumor in relation to the brainstem. When removing large tumors through this approach, the facial nerve can be exposed by early opening of the internal auditory canal. Any size tumor can be removed with this approach. One of the main advantages of the retrosigmoid approach is the possibility of preserving hearing. For small tumors, a disadvantage lies in the risk of long-term postoperative headache.
Middle fossa approach
This approach is in a slightly different incision location and is utilized primarily for the purpose of hearing preservation in patients with small tumors, typically confined to the internal auditory canal. A small wind of bone is removed above the ear canal to allow exposure of the tumor from the upper surface of the internal auditory canal, preserving the inner ear structures.
Advantages of surgery
- Tumor is completely removed and risk of recurrence is less than 0.1%
- One follow-up MRI is needed
- Hearing is preserved and it is stable over time
Disadvantages of surgery
- In some cases, hearing cannot be saved
- Long period of recovery, 4-6 day of hospital stay and 4-6 weeks to regain strength and balance
- Leakage and infection of cerebrospinal fluid through the wound
- Hearing loss
- Facial numbness and weakness
- Ringing in the ear
- Balance problems
- Persistent headaches
- Stroke or brain bleeding
Stereotactic radiosurgery
In single dose treatments, many hundreds of small beams of radiation are aimed at the tumor. This results in a high dose of radiation to the tumor and very little to any surrounding brain structures. Many patients have been treated this way with high success rates. Facial weakness or numbness, in the hands of experienced radiation physicians, occurs in only a small percent of cases. This can be performed with either the linear accelerator or gamma knife. Radiosurgery is a treatment option for patients with smaller tumors (<3 cm) or for patients with enlarging tumors who are not candidates for surgery.
- Complications of stereotactic radiosurgery include:
Stereotactic radiosurgery and fractionated stereotactic radiotherapy
Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (SRT) represent comparable noninvasive treatments for acoustic neuromas. Studies demonstrated at 1-year follow-up, a significantly higher rate of serviceable hearing preservation was achieved in SRT sporadic tumor patients and may therefore be preferable to alternatives including surgery, SRS, or possibly observation in patients with serviceable hearing .[5][6]
References
- ↑ {{Cite journal | author = Jason C. Nellis, Jeff D. Sharon, Seth E. Pross, Lisa E. Ishii, Masaru Ishii, Jacob K. Dey & Howard W. Francis | title = Multifactor Influences of Shared Decision-Making in Acoustic Neuroma Treatment | journal = [[Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology]] | volume = 38 | issue = 3 | pages = 392–399 | year = 2017 | month = March | doi = 10.1097/MAO.0000000000001292 | pmid = 27930442 }}
- ↑ {{Cite journal | author = D. M. Kaylie, E. Gilbert, M. A. Horgan, J. B. Delashaw & S. O. McMenomey | title = Acoustic neuroma surgery outcomes | journal = [[Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology]] | volume = 22 | issue = 5 | pages = 686–689 | year = 2001 | month = September | pmid = 11568680 }}
- ↑ A. Wright & R. Bradford (1995). "Management of acoustic neuroma". BMJ (Clinical research ed.). 311 (7013): 1141–1144. PMID 7580712. Unknown parameter
|month=
ignored (help) - ↑ T. H. Lanman, D. E. Brackmann, W. E. Hitselberger & B. Subin (1999). "Report of 190 consecutive cases of large acoustic tumors (vestibular schwannoma) removed via the translabyrinthine approach". Journal of neurosurgery. 90 (4): 617–623. doi:10.3171/jns.1999.90.4.0617. PMID 10193604. Unknown parameter
|month=
ignored (help) - ↑ DAVID W. ANDREWS, M.D., OSCAR SUAREZ, M.D., H. WARREN GOLDMAN, M.D., PH.D., M. BEVERLY DOWNES, M.S., GREG BEDNARZ, PH.D., BENJAMIN W. CORN, M.D., MARIA WERNER-WASIK, M.D., JEFFREY ROSENSTOCK., M.D. AND WALTER J. CURRAN, JR., M.D. (2001). "STEREOTACTIC RADIOSURGERY AND FRACTIONATED STEREOTACTIC RADIOTHERAPY FOR THE TREATMENT OF ACOUSTIC SCHWANNOMAS: COMPARATIVE OBSERVATIONS OF 125 PATIENTS TREATED AT ONE INSTITUTION". Elsevier Science.
- ↑ STEPHANIE E. COMBS, M.D., THOMAS WELZEL, M.D., DANIELA SCHULZ-ERTNER, M.D., PETER E. HUBER, M.D., PH.D., AND JURGEN DEBUS, M.D., PH.D. (2010). "DIFFERENCES IN CLINICAL RESULTS AFTER LINAC-BASED SINGLE-DOSE RADIOSURGERY VERSUS FRACTIONATED STEREOTACTIC RADIOTHERAPY FOR PATIENTS WITH VESTIBULAR SCHWANNOMAS". Int. J. Radiation Oncology Biol. Phys. 76: 193.