Ugo Fisch

The surgical management of extensive nasopharyngeal angiofibromas with the infratemporal fossa approach

Large juvenile nasopharyngeal angiofibromas are a therapeutic challenge because of their relation to major vasculature and cranial nerves at the base of the skull, and their propensity for recurrence. A classification scheme based on the growth pattern of this tumor is proposed to help the surgeon choose a procedure to access this lesion.

Infratemporal Fossa Approach for Glomus Tumors of the Temporal Bone

The surgical experience with 74 glomus tumors of the temporal bone is presented. The article proposes new refinements in the classification of types C and D tumors and describes in detail the technique of blind sack closure of the external auditory canal, double ligation of the sigmoid sinus and the use of a special infratemporal fossa retractor. The postoperative treatment and intraoperative management of the internal carotid artery, facial nerve and cranial nerves IX, X, XI and XII including the technique and results of a new type of V-VII anastomosis are discussed.

Evaluation of Eardrum Laser Doppler Interferometry as a Diagnostic Tool

Objectives Laser Doppler interferometry (LDI) of the eardrum allows noncontact optical analysis of its vibrations in response to sound. Although LDI has been widely used in research, it has not yet been introduced into clinical practice as an adjunctive test for otological workup. The aim of this study was to evaluate LDI as a diagnostic tool in the clinical sphere.

Rate and Extent of Early Axonal Degeneration of the Human Facial Nerve

Electrophysiologic and histologic studies on a severed human facial nerve have shown that 1) response to stimulation by electroneuronography was lost on the sixth day following injury, 2) wallerian degeneration progressed in a nonuniform “front,” leaving some of the distal stump axons still viable and responsive to intraoperative stimulation 2 days following injury, and 3) the extent of proximal retrograde degeneration was far greater than to the next node of Ranvier. These findings are discussed in light of the current knowledge regarding peripheral nerve degeneration, and explanations are suggested.

Surgical Therapy of Internal Carotid Artery Lesions of the Skull Base and Temporal Bone

Five cases of carotid artery lesions at the skull base or temporal bone, treated surgically, are presented. These lesions include mycotic aneurysms and carotid stenosis secondary to angiofibroma and a glomus caroticum. One case demonstrated an anomalous carotid anatomic pattern with a persistent stapedial artery. A description is provided of the technique of subtotal petrosectomy with permanent anterior displacement of the facial nerve, and middle ear obliteration, thus achieving a safe exposure of the temporal course of the internal carotid artery. The cases indicate that cooperation between temporal bone surgeons and vascular surgeons is a prerequisite to successful repair of such lesions, as good recovery in all five cases was achieved. The techniques allow maintenance of carotid flow during and after repair, reducing the potential for neurologic complications or mortality.

Intraoperative assessment of stapes movement.

A method is described that allows, for the first time, intraoperative vibration modes assessment of the acoustically stimulated stapes by means of scanning laser Doppler interferometry (LDI). The study was designed to answer the following questions: 1) Is LDI practical for taking measurements during surgery? 2) Are the results comparable to the findings in temporal bone preparations? and 3) Do the vibration characteristics of the stapes change after the posterior incudal ligament is detached from the incus? Seven patients with profound bilateral hearing loss who were undergoing cochlear implantation were included in the study. The measurement system was easily applicable for intraoperative measurements and allowed contact-free analysis with very high accuracy. No major differences in the results from the live human subjects and temporal bone preparations were observed. The stapes movement was predominantly pistonlike at the lower frequencies and became complex at higher frequencies. Sacrificing the posterior incudal ligament had no statistically significant effect on stapes vibration.

Polyarteritis nodosa as a cause of sudden deafness. A human temporal bone study.

Pathological changes in the temporal bone are described in a case of polyarteritis nodosa in a 48 year old man in whom the onset of sudden unilateral deafness and vertigo occurred seven months prior to death as one of the early manifestations of the disease. The patient had received only a seven week course of prednisolone and, earlier, a two week course of anti-inflammatory agents. Autopsy revealed involvement of the arteries supplying the kidneys, testes, and pancreas. Changes within the temporal bone were seen bilaterally and there was thickening of the mucosa of the middle ear. Inner ear involvement was mainly limited to the cochlea, the deaf ear showing more pronounced changes. These changes included loss of the organ of Corti in the hook portion of the basal coil, absence of the tectorial membrane, and atrophy of the stria vascularis. The scala tympani was obliterated by fibrosis and new bone formation. The scala media showed hydrops, and a marked decrease in the spiral ganglion cells and nerve fibers supplying this portion of the cochlea was evident. Focal changes were seen throughout the remainder of the cochlea. The vestibular structures showed no detectable pathologic changes. Small vessel arteritis was found in the dural and subacuate vessels in both temporal bones.

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.

Pertlymph Oxygenation in Sudden and Progressive Sénsorineural Hearing Loss

The perilymphatic oxygen tension of the vestibular perilymph of 34 patients with different inner ear losses were measured with the polarographic method before and after inhalation with carbogen. Two patterns of disturbed perilymphatic oxygenation were observed: 1) Characterized by low initial values of perilymphatic oxygenation and normal response to carbogen inhalation was present in sudden deafness and sudden cochleovestibular loss of inner ear function. 2) Characterized by normal initial values of perilymphatic oxygenation and a low response to carbogen, was found in presence of a slowly progressive sensorineural hearing loss. The significance of the obtained results in regard to the possible vascular pathology of the inner ear is discussed.

Management of sudden deafness

Measurements according to the polarographic principle in cats have shown that the factors influencing the perilymphatic oxygen tension are the arterial Pco2, the arterial Po2, and the systemic blood pressure. In patients with sudden deafness, the oxygen supply to the vestibular tissues is significantly reduced but the response to carbogen is still possible. The vasodilation induced by carbogen in sudden deafness is not accompanied by a reduction (stealing effect) but by an increase of perilymphatic oxygenation. Therefore carbogen inhalation was used for the treatment of sudden deafness. In a prospective randomized study, carbogen inhalation yielded significantly better results than the intravenous infusion of papaverine and low-molecular dextran. Carbogen inhalation is recommended for the effective, noninvasive treatment of sudden deafness.