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.

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.

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.

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.

Intraoperative cervical epidurography: a simple modality for assessing the adequacy of decompression during anterior cervical procedures

2003 ◽  
Vol 98 (1) ◽  
pp. 96-99 ◽  
Author(s):  
Nedal Hejazi ◽  
Alfred Witzmann ◽  
Werner Hassler
Keyword(s):  
Real Time ◽  
High Speed ◽  
Low Cost ◽  
Cord Compression ◽  
Real Time Control ◽  
Immediate Feedback ◽  
Content Type ◽  
Bone Removal ◽  
Time Control ◽  
Fine Print

Object. Intraoperative cervical epidurography (ICE) was used during anterior cervical procedures to assess the success of bone resection and indicate the need for immediate correction in the event of inadequate decompression. Methods. The adequacy of decompression was assessed by the operating neurosurgeon who performed ICE after anterior microdiscectomy with exposure of the dura mater. If the decompression was deemed inadequate, additional bone was removed using a high-speed drill. Epidurography was conducted after each subsequent decompression until adequate bone removal was achieved. This was undertaken in 39 patients undergoing anterior cervical procedures. Nine patients underwent corpectomy, 21 one-level, and nine two-level discectomy. The ICE revealed insufficient resections requiring additional bone removal in 14 (36%) of the 39 patients. Conclusions. The goal of ICE is to ensure adequate decompression, and if such has not been achieved, to allow for additional immediate bone excision. Furthermore, ICE provides additional real-time control of the position of cages and screws to avoid dural tear or spinal cord compression. Because of this immediate feedback, the success rate of anterior cervical procedures can be improved. The advantages of this modality include real-time assessment, low cost, simplicity, and speed.

Intraoperative computerized tomography scanning to assess the adequacy of decompression in anterior cervical spine surgery

2001 ◽  
Vol 94 (1) ◽  
pp. 8-11 ◽  
Author(s):  
Stephen R. Freidberg ◽  
Bernard A. Pfeifer ◽  
Peter K. Dempsey ◽  
Edward C. Tarlov ◽  
Michael A. Dube ◽  
...  
Keyword(s):  
Ct Scan ◽  
Computerized Tomography ◽  
High Speed ◽  
Ct Scanning ◽  
Bone Resection ◽  
Content Type ◽  
Intraoperative Ct ◽  
Bone Removal ◽  
Cervical Surgery ◽  
Fine Print

Object. The purpose of this study was to improve the accuracy of bone removal during anterior spinal surgery. Intraoperative computerized tomography (CT) scanning was used to assess the success of bone resection and permit immediate correction in the event of inadequate bone removal. Methods. The Phillips Tomoscan M was used to obtain preoperative cervical scans before and after cervical bone resection was complete. The completeness of bone removal was assessed by the operating neurosurgeon by reviewing the postresection CT scan. If the bone removal was deemed inadequate, additional bone was removed using a high-speed drill. A CT scan was obtained after each subsequent decompression until adequate bone removal was achieved. In 31 patients undergoing anterior cervical decompression intraoperative CT scanning was performed. Nineteen patients underwent corpectomy and 12 discectomy. Of the 31 patients, assessment of intraoperative CT scans obtained in 17 indicated further bone removal was required. Conclusions. Intraoperative CT scanning to monitor bone removal during anterior cervical surgery is a valuable tool to ensure the adequacy of surgery.

Retrosigmoid intradural suprameatal approach to Meckel's cave and the middle fossa: surgical technique and outcome

2000 ◽  
Vol 92 (2) ◽  
pp. 235-241 ◽  
Author(s):  
Madjid Samii ◽  
Marcos Tatagiba ◽  
Gustavo A. Carvalho
Keyword(s):  
Tumor Resection ◽  
Neurological Deficits ◽  
Subtotal Resection ◽  
Middle Fossa ◽  
Meckel’S Cave ◽  
Content Type ◽  
Simpson Grade ◽  
Petroclival Meningiomas ◽  
Meckel's Cave ◽  
Fine Print

Object. The goal of this study was to determine whether some petroclival tumors can be safely and efficiently treated using a modified retrosigmoid petrosal approach that is called the retrosigmoid intradural suprameatal approach (RISA).Methods. The RISA was introduced in 1983, and since that time 12 patients harboring petroclival meningiomas have been treated using this technique. The RISA includes a retrosigmoid craniotomy and drilling of the suprameatus petrous bone, which is located above and anterior to the internal auditory meatus, thus providing access to Meckel's cave and the middle fossa.Radical tumor resection (Simpson Grade I or II) was achieved in nine (75%) of the 12 patients. Two patients underwent subtotal resection (Simpson Grade III), and one patient underwent complete resection of tumor at the posterior fossa with subtotal resection at the middle fossa. There were no deaths or severe complications in this series; all patients did well postoperatively, being independent at the time of their last follow-up examinations (mean 5.6 years). Neurological deficits included facial paresis in one patient and worsening of hearing in two patients.Conclusions. Theapproach described here is a useful modification of the retrosigmoid approach, which allows resection of large petroclival tumors without the need for supratentorial craniotomies. Although technically meticulous, this approach is not time-consuming; it is safe and can produce good results. This is the first report on the use of this approach for petroclival meningiomas.

Circumferential fracture of the skull base causing craniocervical dislocation

2002 ◽  
Vol 97 (1) ◽  
pp. 118-122 ◽  
Author(s):  
Ganesh Rao ◽  
Adam S. Arthur ◽  
Ronald I. Apfelbaum
Keyword(s):  
High Speed ◽  
Unusual Case ◽  
Motor Vehicle ◽  
Neurological Impairment ◽  
Craniocervical Junction ◽  
Motor Vehicle Accidents ◽  
Review Of The Literature ◽  
Content Type ◽  
Vehicle Accidents ◽  
Fine Print

✓ Fractures of the craniocervical junction are common in victims of high-speed motor vehicle accidents; indeed, injury to this area is often fatal. The authors present the unusual case of a young woman who sustained a circumferential fracture of the craniocervical junction. Despite significant trauma to this area, she suffered remarkably minor neurological impairment and made an excellent recovery. Her injuries, treatment, and outcome, as well as a review of the literature with regard to injuries at the craniocervical junction, are discussed.

scholarly journals Resection of a Dumbbell-Shaped Facial Nerve Schwannoma With Preservation of Facial Nerve Function Through the Extended Middle Fossa Approach: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
Kaith K Almefty ◽  
Wenya Linda Bi ◽  
Walid Ibn Essayed ◽  
Ossama Al-Mefty
Keyword(s):  
Facial Nerve ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Growth Patterns ◽  
Geniculate Ganglion ◽  
Nerve Function ◽  
Middle Fossa ◽  
Facial Nerve Function ◽  
Large Tumor ◽  
Middle Fossa Approach

Abstract Facial nerve schwannomas are rare and can arise from any segment along the course of the facial nerve.1 Their location and growth patterns present as distinct groups that warrant specific surgical management and approaches.2 The management challenge arises when the facial nerve maintains good function (House-Brackmann grade I-II).3 Hence, a prime goal of management is to maintain good facial animation. In large tumors, however, resection with facial nerve function preservation should be sought and is achievable.4,5  While tumors originating from the geniculate ganglion grow extradural on the floor of the middle fossa, they may extend via an isthmus through the internal auditory canal to the cerebellopontine angle forming a dumbbell-shaped tumor. Despite the large size, they may present with good facial nerve function. These tumors may be resected through an extended middle fossa approach with preservation of facial and vestibulocochlear nerve function.  The patient is a 62-yr-old man who presented with mixed sensorineural and conductive hearing loss and normal facial nerve function. Magnetic resonance imaging (MRI) revealed a large tumor involving the middle fossa, internal auditory meatus, and cerebellopontine angle.  The tumor was resected through an extended middle fossa approach with a zygomatic osteotomy and anterior petrosectomy.6 A small residual was left at the geniculate ganglion to preserve facial function. The patient did well with hearing preservation and intact facial nerve function. He consented to the procedure and publication of images.  Image at 1:30 © Ossama Al-Mefty, used with permission. Images at 2:03 reprinted from Kadri and Al-Mefty,6 with permission from JNSPG.

Effect of frameless stereotaxy on the accuracy of C1–2 transarticular screw placement

2001 ◽  
Vol 95 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Orin Bloch ◽  
Langston T. Holly ◽  
Jongsoo Park ◽  
Chinyere Obasi ◽  
Kee Kim ◽  
...  
Keyword(s):  
Image Guidance ◽  
Vascular Anatomy ◽  
Ct Scanning ◽  
Screw Placement ◽  
Frameless Stereotaxy ◽  
Transarticular Screw ◽  
Anterior Cortex ◽  
Content Type ◽  
Pars Interarticularis ◽  
Fine Print

Object. In recent studies some authors have indicated that 20% of patients have at least one ectatic vertebral artery (VA) that, based on previous criteria in which preoperative computerized tomography (CT) and standard intraoperative fluoroscopic techniques were used, may prevent the safe placement of C1–2 transarticular screws. The authors conducted this study to determine whether frameless stereotaxy would improve the accuracy of C1–2 transarticular screw placement in healthy patients, particularly those whom previous criteria would have excluded. Methods. The authors assessed the accuracy of frameless stereotaxy for C1–2 transarticular screw placement in 17 cadaveric cervical spines. Preoperatively obtained CT scans of the C-2 vertebra were registered on a stereotactic workstation. The dimensions of the C-2 pars articularis were measured on the workstation, and a 3.5-mm screw was stereotactically placed if the height and width of the pars interarticularis was greater than 4 mm. The specimens were evaluated with postoperative CT scanning and visual inspection. Screw placement was considered acceptable if the screw was contained within the C-2 pars interarticularis, traversed the C1–2 joint, and the screw tip was shown to be within the anterior cortex of the C-1 lateral mass. Transarticular screws were accurately placed in 16 cadaveric specimens, and only one specimen (5.9%) was excluded because of anomalous VA anatomy. In contrast, a total of four specimens (23.5%) showed significant narrowing of the C-2 pars interarticularis due to vascular anatomy that would have precluded atlantoaxial transarticular screw placement had previous nonimage-guided criteria been used. Conclusions. Frameless stereotaxy provides precise image guidance that improves the safety of C1–2 transarticular screw placement and potentially allows this procedure to be performed in patients previously excluded because of the inaccuracy of nonimage-guided techniques.

Extended middle fossa approach to lateralized pontine cavernomas in children

2018 ◽  
Vol 21 (4) ◽  
pp. 384-388 ◽  
Author(s):  
Robert C. Rennert ◽  
Reid Hoshide ◽  
Mark Calayag ◽  
Joanna Kemp ◽  
David D. Gonda ◽  
...  
Keyword(s):  
Trigeminal Nerve ◽  
Internal Auditory Canal ◽  
Csf Leak ◽  
Geniculate Ganglion ◽  
Gasserian Ganglion ◽  
Middle Fossa ◽  
Cavernous Malformations ◽  
Middle Fossa Approach ◽  
Cerebellar Artery ◽  
Mandibular Branch

OBJECTIVETreatment of hemorrhagic cavernous malformations within the lateral pontine region demands meticulous surgical planning and execution to maximize resection while minimizing morbidity. The authors report a single institution’s experience using the extended middle fossa rhomboid approach for the safe resection of hemorrhagic cavernomas involving the lateral pons.METHODSA retrospective chart review was performed to identify and review the surgical outcomes of patients who underwent an extended middle fossa rhomboid approach for the resection of hemorrhagic cavernomas involving the lateral pons during a 10-year period at Rady Children’s Hospital of San Diego. Surgical landmarks for this extradural approach were based on the Fukushima dual-fan model, which defines the rhomboid based on the following anatomical structures: 1) the junction of the greater superficial petrosal nerve (GSPN) and mandibular branch of the trigeminal nerve; 2) the lateral edge of the porus trigeminus; 3) the intersection of the petrous ridge and arcuate eminence; and 4) the intersection of the GSPN, geniculate ganglion, and arcuate eminence. The boundaries of maximal bony removal for this approach are the clivus inferiorly below the inferior petrosal sinus; unroofing of the internal auditory canal posteriorly; skeletonizing the geniculate ganglion, GSPN, and internal carotid artery laterally; and drilling under the Gasserian ganglion anteriorly. This extradural petrosectomy allowed for an approach to all lesions from an area posterolateral to the basilar artery near its junction with cranial nerve (CN) VI, superior to the anterior inferior cerebellar artery and lateral to the origin of CN V. Retraction of the mandibular branch of the trigeminal nerve during this approach allowed avoidance of the region involving CN IV and the superior cerebellar artery.RESULTSEight pediatric patients (4 girls and 4 boys, mean age of 13.2 ± 4.6 years) with hemorrhagic cavernomas involving the lateral pons and extension to the pial surface were treated using the surgical approach described above. Seven cavernomas were completely resected. In the eighth patient, a second peripheral lesion was not resected with the primary lesion. One patient had a transient CN VI palsy, and 2 patients had transient trigeminal hypesthesia/dysesthesia. One patient experienced a CSF leak that was successfully treated by oversewing the wound.CONCLUSIONSThe extended middle fossa approach can be used for resection of lateral pontine hemorrhagic cavernomas with minimal morbidity in the pediatric population.

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