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.

Stereotactic radiosurgery for acoustic nerve tumors in patients with useful preoperative hearing: results at 2-year follow-up examination

1994 ◽  
Vol 80 (6) ◽  
pp. 1011-1017 ◽  
Author(s):  
Olusola K. Ogunrinde ◽  
L. Dade Lunsford ◽  
John C. Flickinger ◽  
Douglas Kondziolka
Keyword(s):  
Stereotactic Radiosurgery ◽  
Trigeminal Nerve ◽  
Cranial Nerve ◽  
Nerve Function ◽  
Content Type ◽  
Acoustic Neuromas ◽  
Cranial Nerve Function ◽  
Acoustic Nerve ◽  
Radiation Beams ◽  
Fine Print

✓ Twenty patients with acoustic nerve tumors (mean diameter ≤ 30 mm) and useful preoperative hearing were examined 2 years after stereotactic radiosurgery to determine the effectiveness of the surgery in the control of tumor growth and the preservation of cranial nerve function. Results showed tumor volume stabilization (12 cases) or reduction (seven cases) was achieved in a total of 19 patients (95%). Useful hearing (defined as Gardner and Robertson Class I or II) preservation was obtained in 100% of cases immediately postoperatively, 50% at 6 months, and 45% at both 1 and 2 years. Two years after stereotactic radiosurgery, facial nerve function was preserved in 90% of patients and 75% continued to have normal trigeminal nerve function. All patients returned to and maintained their preoperative functional status within 3 to 5 days after radiosurgery. These findings indicate that stereotactic radiosurgery with multiple isocenters and narrow radiation beams is a safe and effective management strategy for progressive acoustic nerve tumors. Auditory, facial, and trigeminal nerve function can be preserved in most patients. Prevention of further growth and preservation of cranial nerve function appear to be satisfactory goals in the current management of patients with acoustic neuromas.

Meningiomas involving the cavernous sinus: histological factors affecting the degree of resection

1997 ◽  
Vol 87 (4) ◽  
pp. 535-543 ◽  
Author(s):  
Chandranath Sen ◽  
Karin Hague
Keyword(s):  
Cavernous Sinus ◽  
Internal Carotid ◽  
Skull Base Surgery ◽  
Complete Resection ◽  
Nerve Function ◽  
Content Type ◽  
Factors Affecting ◽  
Cranial Nerve Function ◽  
Histological Factors ◽  
Fine Print

✓ Despite advances in the surgical treatment of meningiomas located at the skull base, surgery for meningiomas involving the cavernous sinus remains controversial. The controversy centers on whether complete resection of such a meningioma is possible while preserving cranial nerve function. To evaluate this question, the authors examined six patients with benign meningiomas involving the cavernous sinus. The pathological features of these tumors were evaluated and compared with the normal histoarchitecture of the cavernous sinus. The tendency of these tumors to be infiltrative is evident and this seems to occur along connective tissue planes within the cavernous sinus. This invasiveness can be explained by the peculiar structure of this region. The trigeminal nerve and ganglion seem to be particularly prone to invasion; this does not correlate with the degree of preoperative impairment of nerve function. Internal carotid artery invasion occurs frequently and can be seen even when there is no narrowing of the artery on arteriography. The pituitary gland can also be invaded by the tumor, which penetrates the thin dural barrier.

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.

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.

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.

Microanatomical variations in the cerebellopontine angle associated with vestibular schwannomas (acoustic neuromas): a retrospective study of 1006 consecutive cases

2000 ◽  
Vol 92 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Prakash Sampath ◽  
David Rini ◽  
Donlin M. Long
Keyword(s):  
Cranial Nerve ◽  
Anatomical Location ◽  
Eighth Cranial Nerve ◽  
Content Type ◽  
Middle Fossa Approach ◽  
Group Iii ◽  
Common Location ◽  
Group I ◽  
Cerebellar Artery ◽  
Fine Print

Object. Great advances in neuroimaging, intraoperative cranial nerve monitoring, and microsurgical technique have shifted the focus of acoustic neuroma surgery from prolonging life to preserving cranial nerve function in patients. An appreciation of the vascular and cranial nerve microanatomy and the intimate relationship between neurovascular structures and the tumor is essential to achieve optimum results. In this paper the authors analyze the microanatomical variations in location of the facial and cochlear nerves in the cerebellopontine angle (CPA) associated with acoustic neuromas and, additionally, describe the frequency of involvement of surrounding neural and vascular structures with acoustic tumors of varying size. The authors base these findings on their experience with 1006 consecutive patients who underwent surgery via a retrosigmoid or translabyrinthine approach.Methods. Between July 1969 and January 1998, the senior author (D.M.L.) performed surgery in 1022 patients for acoustic neuroma: 705 (69%) via the retrosigmoid (suboccipital); 301 (29%) via the translabyrinthine; and 16 (2%) via the middle fossa approach. Patients undergoing the middle fossa approach were excluded from the study. The remaining 1006 patients were subdivided into three groups based on tumor size: Group I tumors (609 patients [61%]) were smaller than 2.5 cm; Group II tumors (244 patients [24%]) were between 2.5 and 4 cm; and Group III tumors (153 patients [15%]) were larger than 4 cm. The senior author's operative notes were analyzed for each patient. Relevant cranial nerve and vascular “involvement” as well as anatomical location with respect to the tumor in the CPA were noted. “Involvement” was defined as adherence between neurovascular structure and tumor (or capsule), for which surgical dissection was required to free the structure. Seventh and eighth cranial nerve involvement was divided into anterior, posterior, and polar (around the upper or lower pole) locations. Anterior and posterior locations were further subdivided into upper, middle, or lower thirds of the tumor.The most common location of the seventh cranial nerve (facial) was the anterior middle third of the tumor for all groups, although a significant number were found on the anterior superior portion. The posterior location was exceedingly rare (< 1%). Interestingly, patients with smaller tumors (Group I) had an incidence (3.4%) of the seventh cranial nerve passing through the tumor itself, equal to that of patients with larger tumors. The most common location of the eighth cranial nerve complex was the anterior inferior portion of the tumor. Not surprisingly, larger tumors (Group III) had a higher incidence of involvement of fourth cranial nerve (41%), fifth cranial nerve (100%), ninth—11th cranial nerve complex (99%), and 12th cranial nerve (31%), as well as superior cerebellar artery (79%), anterior inferior cerebellar artery (AICA) trunk (91.5%), AICA branches (100%), posterior inferior cerebellar artery (PICA) trunk (59.5%), PICA branches (79%), and the vertebral artery (VA) (93.5%). A small number of patients in Group III also had AICA (3.3%), PICA (3.3%), or VA (1.3%) vessels within the tumor itself.Conclusions. In this study, the authors show the great variation in anatomical location and involvement of neurovascular structures in the CPA. With this knowledge, they present certain technical lessons that may be useful in preserving nerve function during surgery and, in doing so, hope to provide neurosurgeons and neurootologists with valuable information that may help to achieve optimum outcomes in patients.

scholarly journals Conquering the Rock—A Retrospective Single-Center Experience of the Transapical Petrosal Transtentorial (Kawase) Approach: Operative Technique and Impact on Cranial Nerve Function

2019 ◽  
Vol 81 (05) ◽  
pp. 526-535
Author(s):  
V. Volovici ◽  
R. Dammers ◽  
C. M. F. Dirven ◽  
E. J. Delwel
Keyword(s):  
Cranial Nerve ◽  
Postoperative Mortality ◽  
Abducens Nerve ◽  
Hearing Preservation ◽  
Petrous Bone ◽  
Nerve Function ◽  
Middle Fossa Approach ◽  
Petroclival Meningiomas ◽  
Cranial Nerve Function ◽  
The Brain

AbstractSince its description in 1985, the transapical petrosal transtentorial or Kawase approach has become a viable option of approaching lesions located in and around the apex of the petrous bone, Meckel's cave, and the anterolateral surface of the brain stem while preserving cranial nerve function. At the Brain Tumor Center, Erasmus MC, 25 patients were treated using the Kawase approach between 2004 and 2018 for various indications, including petroclival meningiomas, chondrosarcomas, pontine cavernomas, trigeminal schwannomas, and posterior circulation aneurysms. Hearing preservation was achieved in all patients; new abducens nerve and trochlear nerve palsies were present in three and six patients, respectively, of which a total of eight required ophthalmological correction. Seven patients experienced a cerebrospinal fluid fistula postoperatively, but this complication appeared self-limiting in all cases, with one patient experiencing secondary meningitis. After modifying our closure technique, the rate of fistulas dropped to zero. The observed direct postoperative mortality was 4% (one patient), although not related to the approach itself. In conclusion, the Kawase approach is a highly complex, but essential middle fossa approach, extremely robust, and able to serve a wide array of pathologies together with its extensions. It is very accurate for performing hearing preservation surgery, but not without caveats and inherent risk of complications.

Facial nerve preservation in patients with large acoustic neuromas treated by a combined middle fossa transtentorial translabyrinthine approach

1982 ◽  
Vol 57 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Charles H. Tator ◽  
Julian M. Nedzelski
Keyword(s):  
Facial Nerve ◽  
Brain Stem ◽  
Cerebellopontine Angle ◽  
Middle Fossa ◽  
Total Removal ◽  
Content Type ◽  
Translabyrinthine Approach ◽  
Acoustic Neuromas ◽  
The Brain ◽  
Fine Print

✓ With large acoustic neuromas, the primary goal of surgery is safe total removal of the tumors, and the secondary goal is preservation of nearby neural structures, including the facial nerve. In a series of 15 consecutive patients with large cerebellopontine angle tumors, all of which were more than 2.5 cm in diameter, tumor excision was performed by a one-stage combined middle fossa-translabyrinthine approach. There were 13 acoustic neuromas, 10 of which were more than 4 cm in diameter, one petrous apex meningioma 4 cm in diameter, and one facial neuroma 3 cm in diameter. The tumors were totally removed in all 15 patients. The facial nerve was preserved in 12 of 13 evaluable patients. In the 14th patient the nerve had been transected in a previous suboccipital procedure with incomplete removal, and in the 15th patient the nerve was sutured following excision of a facial neuroma. Thus, the nerve was lost at surgery in only one patient. This combined approach provided very clear visualization of the cerebellopontine angle, including the brain stem and the lower cranial nerves. It enabled identification of both the origin of the facial nerve at the brain stem and the lateral segment of the nerve in the internal auditory canal. Anterior extensions of tumor growing through the tentorial hiatus were easily removed. The results in these 15 patients show that this approach is excellent for total removal of large acoustic neuromas with preservation of the facial nerve. It is especially suitable for large tumors with anterior extensions.

Reconstruction of the third through sixth cranial nerves during cavernous sinus surgery

1992 ◽  
Vol 76 (6) ◽  
pp. 935-943 ◽  
Author(s):  
Laligam N. Sekhar ◽  
Giuseppe Lanzino ◽  
Chandra N. Sen ◽  
Spiros Pomonis
Keyword(s):  
Cavernous Sinus ◽  
Cranial Nerve ◽  
Recovery Of Function ◽  
Cranial Nerves ◽  
Sinus Surgery ◽  
Content Type ◽  
The Third ◽  
Successful Recovery ◽  
Cranial Nerve Function ◽  
Fine Print

✓ Sixteen reconstruction procedures of the third through sixth cranial nerves were carried out in 14 patients during operations on 149 tumors involving the cavernous sinus. A direct end-to-end anastomosis was performed in five nerves, whereas in 11 cases the nerve stumps were bridged by means of an interposing nerve graft. The sixth cranial nerve was most frequently reconstructed (nine cases). In four cases, the fifth nerve or root was repaired. The third nerve was reconstructed in two patients, and the fourth nerve was repaired in only one case. Recovery of function, either partial or complete, was observed in 13 nerves: the third in two instances, the fourth in one, the fifth in three, and the sixth in seven. No return of function occurred in three nerves. In patients with a successful recovery of cranial nerve function, either binocular function or the cosmetic result was improved. These results suggest that repair of the third through sixth cranial nerves injured during surgery should be pursued in suitable patients.

Stereotactic radiotherapy for the treatment of acoustic neuromas

2004 ◽  
Vol 101 (Supplement3) ◽  
pp. 362-372 ◽  
Author(s):  
Michael T. Selch ◽  
Alessandro Pedroso ◽  
Steve P. Lee ◽  
Timothy D. Solberg ◽  
Nzhde Agazaryan ◽  
...  
Keyword(s):  
Stereotactic Radiotherapy ◽  
Tumor Size ◽  
Cranial Nerve ◽  
Target Volume ◽  
Tumor Control ◽  
Content Type ◽  
Seventh Cranial Nerve ◽  
Acoustic Neuromas ◽  
Fine Print

Object. The authors sought to assess the safety and efficacy of stereotactic radiotherapy when using a linear accelerator equipped with a micromultileaf collimator for the treatment of patients with acoustic neuromas. Methods. Fifty patients harboring acoustic neuromas were treated with stereotactic radiotherapy between September 1997 and June 2003. Two patients were lost to follow-up review. Patient age ranged from 20 to 76 years (median 59 years), and none had neurofibromatosis. Forty-two patients had useful hearing prior to stereotactic radiotherapy. The fifth and seventh cranial nerve functions were normal in 44 and 46 patients, respectively. Tumor volume ranged from 0.3 to 19.25 ml (median 2.51 ml). The largest tumor dimension varied from 0.6 to 4 cm (median 2.2 cm). Treatment planning in all patients included computerized tomography and magnetic resonance image fusion and beam shaping by using a micromultileaf collimator. The planning target volume included the contrast-enhancing tumor mass and a margin of normal tissue varying from 1 to 3 mm (median 2 mm). All tumors were treated with 6-MV photons and received 54 Gy prescribed at the 90% isodose line encompassing the planning target volume. A sustained increase greater than 2 mm in any tumor dimension was defined as local relapse. The follow-up duration varied from 6 to 74 months (median 36 months). The local tumor control rate in the 48 patients available for follow up was 100%. Central tumor hypodensity occurred in 32 patients (67%) at a median of 6 months following stereotactic radiotherapy. In 12 patients (25%), tumor size increased 1 to 2 mm at a median of 6 months following stereotactic radiotherapy. Increased tumor size in six of these patients was transient. In 13 patients (27%), tumor size decreased 1 to 14 mm at a median of 6 months after treatment. Useful hearing was preserved in 39 patients (93%). New facial numbness occurred in one patient (2.2%) with normal fifth cranial nerve function prior to stereotactic radiotherapy. New facial palsy occurred in one patient (2.1%) with normal seventh cranial nerve function prior to treatment. No patient's pretreatment dysfunction of the fifth or seventh cranial nerve worsened after stereotactic radiotherapy. Tinnitus improved in six patients and worsened in two. Conclusions. Stereotactic radiotherapy using field shaping for the treatment of acoustic neuromas achieves high rates of tumor control and preservation of useful hearing. The technique produces low rates of damage to the fifth and seventh cranial nerves. Long-term follow-up studies are necessary to confirm these findings.

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