Using the processus cochleariformis as a multipurpose landmark in middle cranial fossa surgery

2008 ◽  
Vol 123 (2) ◽  
pp. 163-169 ◽  
Author(s):  
T Ulug
Keyword(s):  
Facial Nerve ◽  
Inner Ear ◽  
Middle Cranial Fossa ◽  
The Other ◽  
Coronal Plane ◽  
Intact Bone ◽  
Adjacent Structures ◽  
Cranial Fossa ◽  
Temporal Bones ◽  
Middle Cranial Fossa Surgery

AbstractObjective:To demonstrate that the anatomical structure known as the processus cochleariformis, with its intimate and constant relationships to inner-ear structures, can be used as a reliable landmark during middle cranial fossa surgery, alone or in conjunction with other landmarks.Study design:An anatomical study using cadaveric temporal bones to define six reproducible measurements that relate the processus cochleariformis to inner-ear structures, and to define 14 other measurements that relate inner-ear structures to adjacent structures within the intact bone.Method:Using 10 cadaver specimens, 20 reproducible measurements were defined. The first six of these defined the relation of the processus cochleariformis to inner-ear structures in the middle cranial fossa approach. The other measurements defined the exact location of the inner-ear structures and adjacent structures within the intact bone.Results:The vertical crest lies at a 20° angle from the processus cochleariformis to the coronal plane, and at a distance of 5 to 6 mm from the processus cochleariformis. The point at which the medial margin of the basal turn of the cochlea crosses the labyrinthine segment of the facial nerve lies at a 0° angle from the processus cochleariformis to the coronal plane, and at a distance of 6.5 to 7.5 mm from the processus cochleariformis. The superior semicircular canal lies at a 45° angle from the processus cochleariformis to the coronal plane. The other measurements obtained give important clues about the position of the cochlea, vestibulum, greater superficial petrosal nerve and labyrinthine segment of the facial nerve.Conclusions:If the classical landmarks are indiscernible during middle cranial fossa surgery, then the processus cochleariformis, with its intimate and constant relationships to inner-ear structures, is a safe and constant landmark.

Distance from the Labyrinthine Portion of the Facial Nerve to the Basal Turn of the Cochlea Temporal Bone Histopathologic Study

1996 ◽  
Vol 105 (4) ◽  
pp. 323-326 ◽  
Author(s):  
Miriam I. Redleaf ◽  
Richard R. Blough
Keyword(s):  
Facial Nerve ◽  
Internal Auditory Canal ◽  
Middle Cranial Fossa ◽  
Geniculate Ganglion ◽  
Cochlear Function ◽  
Standard Size ◽  
Basal Turn ◽  
History Of ◽  
Cranial Fossa ◽  
Temporal Bones

The middle cranial fossa approach to lesions of the geniculate ganglion and internal auditory canal preserves cochlear function and affords access to the lateral internal auditory canal. The labyrinthine portion of the facial nerve tends to course near the basal turn of the cochlea, just beneath the middle cranial fossa floor, and is usually dissected in this approach. To determine the distance from the labyrinthine portion of the facial nerve to the basal turn of the cochlea, measurements were obtained in the temporal bones of 24 subjects (48 ears) 9 to 76 years of age. These subjects had no history of facial nerve or ear disease, and had normal audiograms. The distances ranged from 0.06 to 0.80 mm, with 21 of 24 right ears (87.5%) showing distances less than the standard size of the smallest diamond drills (0.6 mm), and 18 of 24 (75%) less than 0.5 mm. Incidental note is made of the distance from the geniculate ganglion to the ampulla of the superior semicircular canal, which ranged from 2.06 to 4.88 mm in the 48 specimens. These measurements can serve as guidelines for the surgeon working in the middle cranial fossa.

The arcuate eminence is not a protrusion of the superior semi-circular canal but a trace of sulcus on the temporal lobe

2000 ◽  
Vol 114 (5) ◽  
pp. 339-344 ◽  
Author(s):  
Atsunobu Tsunoda ◽  
Yurika Kimura ◽  
Takuro Sumi ◽  
Atsushi Komatsuzaki ◽  
Tatsuo Sato
Keyword(s):  
Temporal Lobe ◽  
Internal Auditory Canal ◽  
Middle Cranial Fossa ◽  
Petrous Bone ◽  
The Other ◽  
Inferior Surface ◽  
Important Landmark ◽  
Cranial Fossa ◽  
Temporal Bones ◽  
Occipitotemporal Sulcus

Thirteen cadavers (26 temporal bones) were examined to show the arcuate eminence, especially its correspondence to the superior semicircular canal and inferior surface of the temporal lobe. Arc-like eminences on the petrous bone were observed in 92 per cent of specimens, however, they did not exactly correspond to the superior semi-circular canal. Some eminences corresponded to sulci of the temporal lobe of which most were traces of the occipitotemporal sulcus.On the other hand, a dull, smooth and even domed eminence existed in nine temporal bones independently of the arc-like eminence. Those eminences corresponded to each superior semi-circular canal in only three out of nine specimens.The arcuate eminence was listed as an important landmark in the middle cranial fossa approach. However, in order to drill out the internal auditory canal safely, surgeons should rely on other landmarks or apply other methods from our data.

Microsurgical Anatomy of the Perigeniculate Ganglion Area as Seen from a Translabyrinthine Approach

2000 ◽  
Vol 109 (3) ◽  
pp. 255-257 ◽  
Author(s):  
Ho-Ki Lee ◽  
Won-Sang Lee ◽  
Ek-Ho Lee ◽  
Won Sok Kim
Keyword(s):  
Facial Nerve ◽  
Middle Cranial Fossa ◽  
Surgical Anatomy ◽  
Point Of View ◽  
Microsurgical Anatomy ◽  
Translabyrinthine Approach ◽  
Precise Knowledge ◽  
Cranial Fossa ◽  
Temporal Bones ◽  
Facial Nerve Decompression

Detailed anatomic knowledge of the microsurgical anatomy of the perigeniculate ganglion area is essential to probing adjacent to the facial nerve by a translabyrinthine approach. This study was designed to investigate the surgical anatomy of the perigeniculate ganglion area of the facial nerve from a translabyrinthine point of view. We dissected 15 human temporal bones under a microscope, measured the lengths of the tympanic segment and the labyrinthine segment by a middle cranial fossa approach, and measured the angle between the tympanic and labyrinthine segments by a translabyrinthine approach. The distance of the facial nerve from the cochleariform process to the geniculate ganglion was 3.8 ± 0.7 mm. The length of the labyrinthine segment of the facial nerve was 4 ± 0.8 mm. The angle between the tympanic and labyrinthine segments from a translabyrinthine point of view was 26° ± 5°. Precise knowledge about the microsurgical anatomy of the perigeniculate ganglion area of the facial nerve from a translabyrinthine viewpoint is imperative for facial nerve decompression by a translabyrinthine approach.

Microsurgical Anatomy of the Perigeniculate Ganglion Area as Seen from the Middle Cranial Fossa Approach

2003 ◽  
Vol 112 (6) ◽  
pp. 531-533 ◽  
Author(s):  
Ho-Ki Lee ◽  
Won-Sang Lee
Keyword(s):  
Facial Nerve ◽  
Middle Cranial Fossa ◽  
Point Of View ◽  
Detailed Knowledge ◽  
Geniculate Ganglion ◽  
Microsurgical Anatomy ◽  
Middle Fossa Approach ◽  
Middle Cranial Fossa Approach ◽  
Cranial Fossa ◽  
Temporal Bones

The middle cranial fossa approach is useful for decompressing the perigeniculate ganglion area of the facial nerve in patients with serviceable hearing. The present study was designed to investigate the microsurgical anatomy of the perigeniculate ganglion area of the facial nerve from the point of view of the middle cranial fossa. We dissected 20 human temporal bones under a microscope using a middle fossa approach, and measured the angle between the lines drawn from the malleus head to the vertical crest and from the malleus head to the geniculate ganglion, and the distance from the malleus head to the geniculate ganglion. These were found to be 22.7° ± 2.2° and 6.5 ± 0.3 mm, respectively. Detailed knowledge about the microsurgical anatomy of the perigeniculate ganglion area of the facial nerve from the point of view of the middle cranial fossa is imperative for facial nerve decompression by a middle cranial fossa approach.

Outer Table Graft in Middle Fossa Surgery

1994 ◽  
Vol 111 (1) ◽  
pp. 70-75 ◽  
Author(s):  
Christopher J. Linstrom ◽  
Marek J. Krajewski ◽  
Aaron L. Shapiro ◽  
Salvatore Caruana
Keyword(s):  
Surgical Technique ◽  
Facial Nerve ◽  
Middle Cranial Fossa ◽  
Middle Fossa ◽  
Nerve Decompression ◽  
Cranial Fossa ◽  
Middle Cranial Fossa Surgery ◽  
Facial Nerve Decompression ◽  
Outer Table

We describe a surgical technique in which the middle fossa craniotomy ordinarily used for facial nerve decompression and related surgery is extended superiorly to allow the harvest of a split-thickness calvarial graft. This graft allows the tegmen defect in middle fossa surgery to be repaired without shortening the original craniotomy plate. Avoiding the usual temporoparietal depression after middle cranial fossa surgery is both a structural and cosmetic benefit for the patient.

Evaluation of 3D Printed Temporal Bone Models in Preparation for Middle Cranial Fossa Surgery

2019 ◽  
Vol 40 (2) ◽  
pp. 246-253 ◽  
Author(s):  
Monika E. Freiser ◽  
Anish Ghodadra ◽  
Barry E. Hirsch ◽  
Andrew A. McCall
Keyword(s):  
Temporal Bone ◽  
Middle Cranial Fossa ◽  
3D Printed ◽  
Cranial Fossa ◽  
Middle Cranial Fossa Surgery

Facial Nerve Neuroma

1994 ◽  
Vol 73 (10) ◽  
pp. 721-752 ◽  
Author(s):  
Jack L. Pulec
Keyword(s):  
Facial Nerve ◽  
Signs And Symptoms ◽  
Middle Cranial Fossa ◽  
Nerve Graft ◽  
Surgical Removal ◽  
Optimal Conditions ◽  
Anatomic Site ◽  
Cranial Fossa ◽  
Slow Growing ◽  
Facial Function

Facial nerve neuromas are uncommon, slow-growing neoplasms that may occur anywhere along the course of the facial nerve from the brainstem to the facial muscles. The signs and symptoms are characteristic and vary with the anatomic site of origin. Surgery should not be attempted until a complete and thorough diagnostic examination has been completed. The surgeon should be prepared to perform a middle-cranial fossa or translabyrinthine approach in all cases, and must expect to do a nerve graft. The results of 37 patients treated by the author reveal that, under optimal conditions, patients who have had a facial nerve graft, can be expected to regain an average of 80 % facial nerve strength in almost every case. All patients who have had a facial nerve graft will have some degree of synkinesis. No graft was required in 3 patients, and a hypoglossal facial anastomosis was used for one. Facial function was completely normal in 2 patients, 16 had 80 – 90 % return, 5 patients had 50 – 80 % return, 4 had 20 – 50% return, one had no recovery at all and 9 recent patients have not reached the time for their expected recovery. Early diagnosis, prompt surgical removal and VII - VII Nerve graft for facial paralysis of ten or fewer years duration offers patients the best opportunity to avoid a permanent facial palsy.

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