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At least 19 recordsLinked to original sources
PubMed1993

Petrous bone cholesteatoma.

Petrous bone cholesteatoma is a rare pathologic entity and may be a difficult surgical challenge because of potential involvement of the facial nerve, carotid artery, dura mater, otic capsule, and risk of cerebrospinal fluid leak. The objective of this article is to present a personal classification of petrous bone cholesteatomas, a survey of recent surgical attitudes, and our present surgical strategy based on our experience with 54 operations between 1978 and 1990. Radical petromastoid exenteration with marsupialization and the middle cranial fossa approach were used only for small pure infra- or supralabyrinthine cholesteatomas, respectively. The enlarged transcochlear approach with closure of the external auditory canal was used for infralabyrinthine, infralabyrinthine-apical, and massive petrous bone cholesteatomas. Five cases with petrous bone cholesteatomas in different locations are described in detail to present the signs and symptoms together with the management.

Journal Article↗
PubMed1989

Floating petrous bone fracture.

Floating petrous bone fracture appears to occur when the elastic pediatric skull is subjected to large compressive forces. Unlike a longitudinal fracture, a floating petrous bone fracture does not involve the ear canal and squamous cortex. Rather, the fracture line runs through the middle ear, separating the petrous apex from its lateral and inferior bony attachments. Characteristic clinical findings include immediate onset of conductive hearing loss, with ipsilateral sixth and seventh cranial nerve paralysis. This article details the third known occurrence of this type of fracture, and includes a discussion of the pathophysiologic mechanism and treatment rationale.

Child↗
PubMed1989

[Fine structure analysis of the petrous bone using high-resolution thin-layer computed tomography. 2: Place and success of CT in comparison with conventional x-ray diagnosis of petrous bone fractures].

Thirty patients with suspected petrous fractures following trauma were examined by high resolution CT and by conventional radiography. CT proved the most sensitive method for demonstrating petrous fractures and their complications. CT increased the rate of diagnosis by 17%. All fractures seen on CT could be classified, but accurate classification on the basis of conventional radiographs was only possible in 52% of cases. High resolution CT is superior in demonstrating damage to the labyrinth and the ossicles. Indications for conventional tomography are confined to atypical fractures with a course unsuitable for CT.

Humans↗
PubMed2006

Endolymphatic sac carcinoma of the right petrous bone in Von Hippel-Lindau disease.

A large endolymphatic sac papillary adenocarcinoma in a patient with Von Hippel-Lindau (vHL) disease is reported. A 31-year-old man was treated for a left eye retinal angioma 10 years previously and had been blind in that eye since. He was admitted with progressive tinnitus, lower cranial nerve paresis and ataxia. Investigations revealed a vascular and bone-eroding petrous tumour. The entirely extradural tumour involved a large part of the petrous bone and extended into the cerebellopontine angle. The vascular tumour was radically resected using a presigmoid approach after feeding vessel embolisation. The literature on this rare clinical entity is briefly discussed.

Adenocarcinoma, Papillary↗
PubMed1984

On the functional morphology of the human petrous bone.

In this study the human petrous bone was investigated to find out whether and in what way it is adapted to mechanical stress by inner bone structure. Three normally formed petrous bones were cut in serial sections and examined by means of microradiography and circular polarized light with respect to mineralization, distribution of bone structure, and collagen fiber arrangement over the cross section. It has been shown that the human petrous bone can be divided morphologically into four different bony layers: 1) endosteal; 2) enchrondral ; 3) inner periosteal layers, which together form the labyrinthine capsule and which are characterized by a higher level of mineralization and show no clear indication of bone remodeling; and 4) outer periosteal layer, in which numerous osteons indicate appositional and resorptional growth processes. The collagen fibers in the labyrinthine capsule are arranged in an irregular web-like pattern, whereas in the outer periosteal layer they run predominantly parallel to the surfaces of the petrous bone, probably to minimize the mechanical stress in the form of a tension band. These results support the assumption that in the human petrous bone, the outer periosteal layer is adapted to resorb elastic deformation, whereas the brittle labyrinthine capsule is better adapted to the functions of an auditory and vestibular organ.

Adaptation, Physiological↗
PubMed2002

[CT and MRI of the petrous bone].

Diseases of the petrous bone should now be diagnosed by means of high-resolution multislice spiral computed tomography (MSCT) and/or magnetic resonance imaging (MRI). The first step in the process of diagnosis, however, must be conventional X-ray photographs (according to Schüller, Mayer, Stenvers) for screening purposes, because of the high cost of the other procedures mentioned. Because of the excellent imaging of bone structures with MSCT, this technique is especially suitable for the diagnosis both of acquired pathologies and of congenital abnormalities of the external auditory meatus, the middle ear and the mastoid, of trauma-induced pathologies of the entire petrous bone, and of osteogenic diseases. MRI is the method of choice for examination of the labyrinthine system, the interior auditory meatus and the cerebellopontine angle because it gives much the best depiction of soft tissue. Sometimes when questions remain unsolved after computed tomography (CT) examination of the middle ear MRI can be applied to complement CT, and it can yield additional information. Lesions affecting the apex of the petrous pyramid should be examined by MRI. High-resolution CT through the bone window and thin-layer MRI are both components of the presurgical diagnosis before cochlear implant (CI) surgery. For postoperative monitoring a conventional transorbital X-ray of the petrous bone is sufficient; CT is indicated only in complicated cases, and MRI is absolutely contraindicated after CI.

Artifacts↗
PubMed2001

[Petrous bone cholesteatoma: surgical strategy].

Petrous bone cholesteatoma is a rare pathology which grows slowly and is often asymptomatic. This work presents a series of 25 cases of Petrous bone cholesteatoma and discusses the diagnostic impact, the surgical approach, the results and the complications. Currently our surgical orientation favors translabyrinthine and transcochlear approaches which, better than other ones, allow both radical excision of the lesion and preservation of the main neuro-vascular structures. Out of the 25 patients undergoing surgery, 22 were treated with the translabyrinthine (6 cases) or transcochlear (16 cases) approaches, in 1 case an infratemporal type A approach was used while the remaining 2 were treated with a median cranial fossa approach. Paralysis of the facial nerve is the most dreaded complication, particularly when a deficit is already present prior to surgery. In just a few cases did the hearing justify an attempt at preservation but in no case should this compromise radical removal of the cholesteatoma.

Adult↗
PubMed1993

[Aneurysmal bone cyst of the petrous bone. A rare cause of recurrent bacterial meningitis].

Occult malformations of the skull base are very rare disorders which cannot initially be diagnosed clinically. They become first symptomatic, if complications arise. The most frequent clinical manifestation is a recurrent bacterial meningitis. Based on the unique case of a presumably congenital aneurysmal bone cyst of the petrosal bone, which imposed clinically as hearing loss and recurrent bacterial meningitis, we have evaluated the extensive literature on this theme. Considering mostly atypical clinical findings, solely coronal thin-section computed tomographic scans of the skull base allow a reliable diagnosis. The possible risks of this investigation (necessary sedation up to insufflation anesthesia and the radiation exposure of the child's lens) are justifiable and subordinate to the diagnostic importance.

Adolescent↗
PubMed1991

Facial nerve and medially invasive petrous bone cholesteatomas.

Eight patients with extensive petrous bone cholesteatomas that invaded the labyrinth and fallopian canal are presented. The eight cases are added to a tabulation of prior literature reports to elucidate concepts of routes of extension of medially invasive temporal bone cholesteatoma. Medially invasive petrous bone cholesteatoma develops insidiously, often without symptoms other than facial palsy and/or unilateral deafness. Typically, a history of chronic ear disease can be obtained. While hearing is unlikely to be preserved in this group of patients, facial nerve function can usually be preserved, and a facial nerve graft was not necessary in our series. Acute facial nerve palsy or facial nerve paresis progressing to palsy in patients with a history of chronic ear disease should be studied radiographically for petrous bone cholesteatoma, even if there is no physical evidence of cholesteatoma.

Adult↗
PubMed1983

[Giant cell tumour of bone in the cavum tympani and petrous bone].

In the great majority of cases, the giant-cell tumour of bone (synonymous with osteoclastoma of bone) is localised at the end of a long tubular bone. Most of the patients are between 20 and 40 years of age. A case of a grade II giant-cell tumour in a female patient of 32 years of age is reported, which was localised in the middle ear and petrous bone.

Adult↗
PubMed1994

[Diploic epidermoid on the petrous bone: a case report].

An unusual case of a congenital petrous bone epidermoid which resulted in a sudden deafness is reported. The patient was a 25-year-old man who suddenly developed a right deafness and tinnitus. Neurological examination on admission revealed slight hearing disturbance in the high sound area. Plain craniogram showed a destructive bone lesion in the middle portion of the petrous bone on the right side. Bone-window CT scan disclosed a bony destructive mass in the petrous bone, and enlargement of the internal auditory canal. The mass lesion was almost isodense on plain CT scan and was not enhanced by contrast media. T1 weighted imaging of MRI demonstrated an isointense mass in the petrous bone, and T2 weighted imaging demonstrated hyperintensity. Gd-DTPA MRI revealed no enhancement. Angiogram did not reveal abnormal findings. Right lateral suboccipital craniectomy was performed to remove the posterior wall of the internal auditory canal. The tumor existed extradurally originating from the dipole of petrous bone. The tumor appeared pearly and fragile. The pathological examination of the specimen was diagnosed as epidermoid. The postoperative course was uneventful except for right hearing loss on the 4th postoperative day. Epidermoid arising in the middle portion of the petrous bone is quite rare, so this case was hereby reported with some references.

Adult↗
PubMed1980

Attenuation profiles of the petrous bone with acoustic neuroma.

Attenuation profiles across the petrous bone covering the whole internal auditory meatus (IAM) were constructed from the printouts obtained by computed tomography (CT) with narrow collimation performed on 12 patients with 13 acoustic neuromas. In healthy patients the attenuation profiles of right and left petrous bone were very similar in shape. The attenuation values of the individual pixels in the pixel columns of the printout located at the site of the porus and the IAM reflected the demineralization of the petrous bone and the widening of the porus and the IAM caused by the acoustic neuroma. A widening deep in the meatus was demonstrated in a patient with an intracanalicular tumor, and therefore it seems possible to make this diagnosis by CT scanning combined with the construction of attenuation profiles across the petrous bone. In the presence of unilateral acoustic neuroma there was a significant and characteristic difference in shape between the attenuation profiles of the two sides with generally lower attenuation values on the tumor side together with signs of widening of the porus and the IAM. In cases of bilateral acoustic neuroma comparison of the attenuation profiles can be made with mean attenuation curves obtained from scanning normal petrous bones. The prevailing physical limitations for demonstrating a narrow bony canal like the IAM with CT was experimentally analyzed using bone-simulating plastic material.

Humans↗
PubMedDate not supplied

Artificial petrous bone produced by stereolithography for microsurgical dissecting exercises.

Training in microsurgery of the middle ear requires dissecting to be carried out on petrous bone. Human petrous bone structures are not available in adequate quantity to permit extensive practicing. Using synthetic resins, true reproductions of petrous bone can be obtained by means of a stereolithographic method, yielding structures of the petrous part which are highly similar to human bone. Digital data sets are obtained from spiral CT scans, and transferred to CAD systems such that, using stereolithography, petrous bone facsimiles are produced on the parametric model. Any number of such models of an original can be produced. Thus, identical structures can be made available for a wide range of uses. Exercises conducted on artificial petrous bone so produced are equivalent to those carried out on human structures, in terms of material properties and visualisation of anatomic details.

Anatomy↗
PubMed1993

[Facial nerve and petrous bone cholesteatoma].

The diagnosis and treatment of petrous bone cholesteatoma is a challenge to aural surgeons. Seven patients with extensive petrous bone cholesteatomas which invaded the labyrinth and fallopian canal are presented. These cholesteatomas originated as secondary to acquired lesions. The cases were evaluated according to the clinical features, the intraoperative findings, the radiological findings, and the surgical approaches. In this series, six patients presented with facial paralysis associated with profound or total deafness. The transtemporal lateral approach was used in all the cases. Acute facial nerve palsy or facial nerve pareses progressing to palsy in patients with chronic ear disease should be studied radiographically for petrous bone cholesteatoma, even if there is no physical evidence of cholesteatoma.

Adolescent↗
PubMed2003

Computed tomography evaluation of air cells in the petrous bone--relationship with postoperative cerebrospinal fluid rhinorrhea.

The anatomy of air cells in the petrous bone was investigated using thin-slice bone-window computed tomography (CT) of 168 petrous bones in 84 patients. Air cells in the petrous bone were classified into mastoid and petrous cells. Petrous cells were subdivided into perilabyrinthine and apical cells. Perilabyrinthine cells comprised supralabyrinthine and infralabyrinthine cells. Supralabyrinthine cells were subdivided into posterosuperior, posteromedial, and subarcuate cells. The mastoid was classified as eburnated (11%) or pneumatized (89%) by the extent of the mastoid cells. The mastoid cells were classified into presinusoidal (14%), sinusoidal (44%), and postsinusoidal (42%) according to the relationship with the sigmoid sulcus. The extent of the mastoid cells was significantly correlated with the pneumatization of the petrous apex, i.e. the apical cells (p < 0.01). CT precisely depicted the complex anatomy of the air cells in the petrous bone. Cerebrospinal fluid (CSF) rhinorrhea is the most common complication after skull base surgery for cerebellopontine angle tumors. Air cells in the petrous bone provide the route for CSF rhinorrhea. Therefore, CT assessment of the air cells is useful for preventing this complication.

Adult↗
PubMed2000

Low-dose high-resolution CT of the petrous bone.

PURPOSE: To show that CT of the petrous bone can be realized using a low-dose technique. MATERIAL: and methods: A high-contrast phantom was scanned with 1.5 mm slice thickness and 60-510 mAs using the reconstruction algorithms standard, bone and edge. In 50 patients, the petrous bone was examined using the standard protocol at 510 mAS. Additionally, selected slices were made at 120 or 210 mAs. The resolution of relevant structures was compared. Phantom studies were repeated on a second CT-device; images of patients scanned with 80 mAs were analyzed in regard to resolution of osseous details. RESULTS: With the first CT-device structures of the phantom up to 0. 5 mm were depicted using 510 mAs and the edge kernel. With 120 mAs and the bone kernel structures of 0.6 mm could be distinguished. Although the same resolution was achieved with 60 mAs and the edge kernel, patient examinations showed a profound image noise. The results achieved with 120 mAs and the bone algorithm, however, were equal to that of 510 mAs. With the second device the same image quality was realized with only 80 mAs. CONCLUSION: CT-examinations of the petrous bone can be effected without loss of diagnostic information using only 15% of the radiation dose used for a standard brain examination.

Humans↗