Morphology of the malleus handle and the comparison of different prostheses for malleostapedotomy.

OBJECTIVES: To assess malleus morphology to characterize optimal sites for prosthesis attachment in malleostapedotomy and to examine attachment, position, and depth of penetration in the vestibule of the 3 most used prostheses. METHODS: Ten mallei were processed for histologic examination with the light microscope. Using digitized video images of the histologic slices, the diameters, circumference, and shape of the specimen were determined. Implantation of 3 prostheses (Gyrus Nitinol piston, Storz titanium stapes piston, and Kurz malleovestibulopexy piston), was performed in 3 temporal bones for a total of 27 implantations. RESULTS: The cross-section of the malleus just distal to the lateral process shows an inclined oval shape with a mean minimum diameter of 0.84 +/- 0.10 mm, a mean maximum diameter of 1.02 +/- 0.23 mm, and a mean circumference of 3.23 +/- 0.49 mm. The quality of attachment to the malleus, the position of the prosthesis piston, and the depth of penetration were reliable for the Storz titanium stapes piston, satisfactory though variable for the Gyrus Nitinol piston and poor for the Kurz malleovestibulopexy piston as judged by contact with the malleus surface and predictability of insertion depth into the vestibule. CONCLUSION: The oval and inferoanteriorly inclined shape of the malleus distal to the lateral process requires the use of a prosthesis capable of molding itself to its surface for reliable attachment. To achieve the correct perpendicular position of the piston as it relates to the stapedotomy opening, individualized adaptation of the prosthesis shaft and loop to the anterior position of the malleus should be made in situ.

Transotic approach to the cerebellopontine angle. 1992.

The transotic approach to the cerebellopontine angle has been developed at the University of Zurich for the removal of acoustic tumors in an effort to increase operative exposure and enhance facial nerve preservation and reconstruction. Key steps involve the total removal of all pneumatic cell tracts with middle ear and eustachian tube obliteration, followed by complete otic capsule removal for tumor exposure. This article discusses the advantages, disadvantages, and technique of this approach.

A checklist for surgical exposure in stapes surgery: how to avoid misapprehension.

The goal of middle ear exploration in stapes surgery is to identify impairments of function along the entire ossicular chain. The endaural approach with an extended tympanomeatal flap and an almost routinely performed anterosuperior canalplasty allow adequate exposure to identify the anterior malleal ligament and process (1), the inferior incudomalleal joint (2), the entire stapes including the pyramidal process (3), and the round window niche (4). With this checklist at hand the otologic surgeon can define the exact location of the hearing impairment and choose the proper technique for hearing reconstruction in primary and revision surgeries.

The crimping problem in stapes surgery.

AIM OF THE STUDY: The goal of this study was to compare the attachment of stapes prostheses with differently shaped loops to the long process of the incus. METHOD: Gold, steel/Teflon, platinum/Teflon, and two different titanium stapes prostheses were inserted in 30 specially prepared temporal bones by three experienced surgeons using the Fisch technique with the McGee crimper and straight alligator forceps for the crimping of the loops. RESULTS: In all prostheses, a sufficiently firm attachment of the long process of the incus was achieved. The band-shaped loops showed a better contact with the incus than did the wire loops. However, the broad spiral-shaped loops led to a loss of the perpendicular axis of the piston to the long incus process. CONCLUSION: The geometry of the loop affects the final length of the piston in the vestibule and its angle to the long process of the incus.

Stapes surgery: the diameter of the long process of the incus.

HYPOTHESIS: The aim of this study was to examine the long process of the incus in respect of its shape and its dimensions at the site of the attachment of a stapes prosthesis. BACKGROUND: One of the complications in stapes surgery is the erosion of the long process of the incus at the site of the attachment of the prosthesis, resulting in a fluctuating conductive hearing loss. Knowing the dimensions of the attachment site of the prosthesis at the long process of the incus will make it possible to optimize the size of the prosthesis loop. METHODS: The incus was obtained from 11 patients who had undergone middle ear surgery for hearing improvement or cholesteatoma removal. The ossicles were kept in 4% paraformaldehyde and were processed for histological examination after decalcification in ethylenediamine tetra-acetic acid. The 5-microm slices were stained with toluidine blue and examined in the light microscope. Using digitized video images of the histological slices, the diameters, circumference, and surface of the specimens were determined. RESULTS: The diameter of the long process of the incus at 1.4+/-0.28 mm from the tip, which is the average site of prosthesis attachment, showed an oval shape with a minimum diameter of 0.66+/-0.05 mm, a maximum diameter of 0.81+/-0.1 mm, and a circumference of 2.46+/-0.23 mm. CONCLUSION: The loop of a stapes prosthesis should have the following dimensions: diameter 0.9 mm, loop length of 2.2 mm, and opening of loop 0.7 mm. However, the material of the prosthesis and its malleability are also important factors.

Otosclerosis: incidence of positive findings on high-resolution computed tomography and their correlation to audiological test data.

OBJECTIVES: Computed tomographic (CT) scanning with slices of 1 mm or more has not been sufficient to demonstrate otosclerotic foci in most cases to date. METHODS: We investigated the validity of CT scans with a 0.5-mm cubical scan technique, with and without planar reconstruction, and correlated these findings with audiological data. Forty-four temporal bone CT scans from 30 patients with conductive or mixed hearing loss were evaluated. RESULTS: Otosclerotic foci were visualized in 74% of the cases. With reconstruction at the workstation, the sensitivity increased to 85%. Whereas in fenestral otosclerosis a correlation was found between the size of the focus and the air-bone gap, no correlation was seen between the size of the focus and bone conduction thresholds with cochlear involvement. Otosclerotic foci in patients treated with sodium fluoride were smaller than those in patients without treatment. This finding may indicate a beneficial effect of sodium fluoride on otosclerotic growth. CONCLUSIONS: High-resolution CT scans are a valid tool that can be used to confirm, localize, and determine the size of clinically suspected otosclerotic foci.

A new L-shaped titanium prosthesis for total reconstruction of the ossicular chain.

OBJECTIVE: To describe the technique used for total ossiculoplasty with the Fisch titanium total prosthesis and evaluate the 1-year postoperative functional results in patients presenting with the stapes (or footplate) without the malleus handle. STUDY DESIGN: Prospective trial with preoperative and postoperative comparison. SETTING: Academic and private practice tertiary care center for otologic surgery. PATIENTS: Forty-nine consecutive patients operated on from September 1996 to December 2000. SURGERY: : Staged ossicular reconstruction with a Fisch titanium total prosthesis placed between the footplate and the tympanic membrane without regard to the presence or absence of the stapes arch. Coupling of the prosthesis to the footplate was achieved by various techniques, including perforation, foot and spike on the footplate without perforation, and shaft alone (without foot) with tragal cartilage fixation (disc or small wedges). There was no interposition of cartilage between the prosthesis head and the tympanic membrane. MAIN OUTCOME MEASURES: Pre- and postoperative air and bone-conduction thresholds and air-bone gaps for pure-tone averages of three and four frequencies and for single frequencies. RESULTS: Postoperative air-bone gap closures within 20 dB distributed equally (50%) between 0.5, 1, and 4 kHz and reached the highest rate (89%) at 2 kHz (p < 0.05). The postoperative air-bone gaps for pure-tone averages reached 0 to 20 dB in 57% and 0 to 30 dB in 87% of the cases. There were no dead ears and no partial or total extrusions of prostheses. The best functional results were achieved through perforation coupling of the spiked foot to the footplate in large oval windows and after fixation of the shaft (without foot) with tragal cartilage disc in narrow oval windows. CONCLUSION: The functional results of the L-shaped Fisch titanium total prosthesis implanted in ears with the stapes but no malleus handle are best at 2 kHz and better than those of comparable columellar titanium prostheses over the remaining tested frequencies.

Fixation of the anterior mallear ligament: diagnosis and consequences for hearing results in stapes surgery.

In the search for possible causes of unfavorable results after stapes surgery, the study reported here focused on the anterior mallear ligament, since it has been previously reported that partial mallear fixation (PMF) leads to functional failure in 38% of cases of stapes revision surgery. The aims of the study were to identify effective methods for the diagnosis of PMF and experimentally assess the conductive hearing loss that results from PMF. The study included vibration amplitude measurements of the ossicles by laser Doppler interferometry (LDI) in 19 patients and 5 fresh human temporal bone (TB) specimens. Analysis of their dynamic behavior was performed by finite element modeling (FEM). Similar, significant changes of manubrium vibration patterns for PMF were found by FEM calculations, in TB experiments, and in patients. We could identify PMF either before operation, using LDI, or during operation, by manual palpation. In the TB experiments and FEM calculations, the attenuation of the stapes displacement due to an isolated PMF was approximately 10 dB and frequency-dependent. Untreated anterior mallear ligament fixation produced a persistent air-bone gap of approximately 10 dB after stapedioplasty.

The anterior and superior malleal ligaments in otosclerosis: a histopathologic observation.

HYPOTHESIS: The aim of this study was to assess, in otosclerosis, whether the anterior and superior malleal ligaments show histologic changes that can lead to reduced malleal mobility and eventual fixation, and also to evaluate whether these changes are related to the degree of histologic otosclerosis. BACKGROUND: Fixation of the malleus seems to be one of the most controversial clinical entities in the acquired condition of otosclerosis. It has even been postulated that persistent conductive deafness, or progression of conductive deafness after initial improvement after stapedotomy, could be due to unsuspected malleus fixation. METHODS: Fifty eight temporal bones with known otosclerosis and 43 normal temporal bones were selected. In addition, 10 temporal bones of fetuses and children were also studied. Otosclerosis of the footplate and otic capsule was graded as none, mild, moderate, and severe. The histologic changes in the ligaments also were graded from none to severe. RESULTS: The median ages of patients in the otosclerotic and normal groups were 62 and 60 years, respectively. In the anterior malleal ligament of the otosclerotic bones, 10% mild (+), 60% moderate (++), and 30% severe (+++) degrees of hyalinization were observed. In the anterior malleal ligament of the nonotosclerotic bones, 14% showed no hyalinization, 24% had only a tinge of hyalinization (minimal), 51% had mild (+) hyalinization, and 11% had moderate (++) hyalinization. Superior ligament hyalinization appears to be related to the severity of anterior ligament hyalinization. The severity of otosclerosis in the footplate or the otic capsule did not appear to be related to the severity of hyalinization. CONCLUSION: From this study, it is apparent that otosclerotic bones have a significantly high incidence of hyalinization of the anterior malleal ligament. This seems to be related to the duration rather than the severity of otosclerosis. It is important to properly evaluate malleal mobility during all stapes surgery.

Arachnoid cyst of the fallopian canal: a surgical challenge.

OBJECTIVE: Spontaneous cerebrospinal fluid (CSF) leaks from the fallopian canal are exceedingly rare, with only 6 reports appearing in the world literature. We report a seventh case that is unique in that it involves an arachnoid cyst of the fallopian canal and an associated facial nerve palsy. STUDY DESIGN: Case report. SETTING: International tertiary care referral center. CONCLUSION: CSF otorhinorrhea associated with a facial nerve palsy may be indicative of an arachnoid cyst of the fallopian canal. These fistula are extremely rare. Surgical management involves sealing the fistula while preserving facial nerve function and is extremely challenging.

Stapes surgery: how precisely do different prostheses attach to the long process of the incus with different instruments and different surgeons?

HYPOTHESIS: The goal of this study was to compare the attachment of stapes prostheses with differently shaped loops to the long process of the incus. BACKGROUND: In stapes surgery, the attachment of the prosthesis to the long process of the incus plays an important role concerning the gain in hearing and the development of late complications such as incus erosion and necrosis. Band-shaped and spiral loops have been developed to achieve a broad, firm attachment to the long process of the incus. During stapes surgery, the view at the prosthesis is restricted, making it impossible to evaluate the effects of the differently shaped loops. METHODS: Gold, steel/Teflon, platinum/Teflon, and two different titanium stapes prostheses were inserted in 30 specially prepared temporal bones by three experienced surgeons using the Fisch technique with the McGee and straight alligator forceps for the crimping of the loops. Photographs were taken with 0- and 70-degree rod lens telescopes at defined views. RESULTS: In all prostheses, a sufficiently firm attachment to the long process of the incus was achieved. The attachment of band-shaped loops proved to be better with the straight alligator forceps. The band-shaped loops showed a better contact with the incus than did the wire loops. However, the broad spiral-shaped loops led to a loss of the perpendicular axis of the piston to the long incus process. CONCLUSION: The geometry of the loop affects the final length of the piston in the vestibule and its angle to the long process of the incus.

Evaluation of paragangliomas presenting as a cervical mass on color-coded Doppler sonography.

OBJECTIVES: To assess the potential of color Doppler sonography to identify cervical mass lesions as paragangliomas. STUDY DESIGN: Prospective evaluation. METHODS: Fifteen patients with 18 paragangliomas (13 carotid body tumors, 3 vagal and 2 temporal) presenting as a mass in the neck were investigated using color Doppler sonography. RESULTS: All paragangliomas presented in B-mode sonography as solid, well-defined, and hypoechoic tumors. Color Doppler imaging revealed hypervascularity in 15 (82%) tumors. No flow signal was detected in 3 carotid body tumors at standard velocity encoding (30 cm/s). Only carotid body tumors could be assessed in their full extent. Temporal and vagal paragangliomas were only partially visible. Carotid body tumors showed a splaying of the carotid bifurcation with displacement of the external carotid anteriorly and both the internal carotid and the internal jugular vein posteriorly. Anterior displacement of both carotid arteries and posterior displacement of the internal jugular vein was found in the 3 vagal paragangliomas. The caudal tumor extension of the 2 temporal paragangliomas was recognized within the expanded lumen of the internal jugular vein. According to the direction of tumor growth and vascular supply, the intratumoral flow signal was predominantly directed upward in carotid body tumors and downward in vagal and temporal paragangliomas. CONCLUSIONS: Based on the appearance in the B-mode, the hypervascularity, the relationship toward the carotid arteries and the internal jugular vein, and the intratumoral flow direction, color Doppler sonography was able to establish the diagnosis and type of a paraganglioma.