Long term surgical and hearing outcomes in the management of tympanomastoid paragangliomas.

OBJECTIVE: To analyze the long term outcomes after surgery in tympanomastoid paragangliomas. STUDY DESIGN: Retrospective study. METHODS: The charts of 145 patients with tympanomastoid paragangliomas managed between 1988 and 2013 were reviewed. The clinical features, audiological data, pre- and postoperative notes were noted. The tumors were staged according to the modified Fish and Mattox classification. The surgical approaches for all patients were formulated according to the surgical algorithm developed at our center. RESULTS: 34 (23.5%), 46 (31.7%), 22 (15.2%), 18 (12.4%) and 25 (17.2%) patients were diagnosed to have TMP class A1, A2, B1, B2 and B3 tumors respectively. Gross tumor resection was achieved in 141 (97.2%) patients. The facial nerve was uncovered in four patients and infiltrated in three. The cochlea was found eroded in seven cases. The mean follow-up was 48.4 months. Recurrence was seen in one patient (0.7%). In the cases where the facial nerve was preserved (n=143), the nerve function was graded as HB grade 1 in 138 patients (97%). Postoperatively, the mean AC showed an improvement in all categories except in class B2 and B3, which corresponds to the classes that include patients who underwent subtotal petrosectomy. CONCLUSION: We report the long term surgical outcomes in tympanomastoid paragangliomas in the largest series published till date. It is possible to completely eradicate all types of tympanomastoid paragangliomas with minimum sequelae by choosing the correct surgical approach to achieve adequate exposure for individual tumor classes as described in our classification and algorithm. LEVEL OF EVIDENCE: IIb.

Multi-electrode sequential versus single electrode stimulation to elicit the stapedial reflex during cochlear implantation: Correlation with maximum comfort level.

OBJECTIVES: To assess whether electrical stimulation sequentially delivered through 4 electrodes located in different cochlear areas may elicit the stapedial reflex at lower levels compared to single electrode stimulation and to correlate the sequentially obtained values with the maximum comfort level (C-level). PATIENTS AND METHODS: A retrospective study was performed on 35 post-verbal adult patients (age 19-80 years) consecutively implanted in 2 cochlear implant centers, evaluating the level of stimulation (pulse width) necessary to electrically evoke the stapedial reflex with two different stimulation modalities: single electrode versus sequential 4 electrode stimulation. Threshold values were compared with C-level obtained at activation. RESULTS: The average differences of pulse width and C-level were significantly smaller (P<0.0001) when the stapedial reflex was obtained with the sequential stimulation modality and reached statistical significance for every single electrode (P<0.0001). CONCLUSIONS: Stapedial reflex thresholds obtained with sequential stimulation through 4 different electrodes significantly correlate to the C-level obtained at the first setting and may be helpful in defining the upper limit of the dynamic field during initial CI mapping.

Infratemporal fossa approaches to the lateral skull base.

The infra-temporal fossa approach is one of the lateral approaches to the skull base. It is indicated for the treatment of tumors such as glomus tumor, petrous apex cholesteatoma, chondroma, lower cranial nerve neuroma and nasopharyngeal cancer. In the present paper, we described the surgical anatomy of the lateral skull base and the indications for the infra-temporal fossa approach with its variants. We showed the hints and pitfalls in the procedures. Five illustrative cases are also presented.

Meningoencephalic herniation into the middle ear: a report of 27 cases.

Meningoencephalic herniation into the middle ear is a rare and potentially life-threatening condition that may require prompt surgical intervention. Preoperative diagnosis is based on a high index of suspicion. Sometimes, however, meningoencephalic herniation is discovered during surgery. High-resolution computed tomography and magnetic resonance imaging should be performed to confirm the diagnosis and to evaluate the extension of the herniated tissue. This article discusses the diagnostic approach, management strategy, and surgical technique used in 27 patients with meningoencephalic herniation. In an attempt to avoid infective complications, the authors used the middle cranial approach in patients with large herniations.

Identification of the facial nerve in the translabyrinthine approach: an alternative technique.

An alternative technique for the identification of the facial nerve at the fundus of the internal auditory canal is described.

Electromyographic evaluation of facial nerve damage in acoustic neuroma surgery.

OBJECTIVE: This study aimed to determine whether postoperative facial nerve paralysis or surgical manipulation causing paralysis could be predicted on train responses during intraoperative facial nerve monitoring in acoustic neuroma surgery. STUDY DESIGN AND SETTING: This was a prospective study performed at a tertiary referral center. PATIENTS AND METHODS: Train responses were recorded on a floppy disk and compared with postoperative facial nerve function in 51 patients who underwent enlarged translabyrinthine acoustic neuroma surgery. MAIN OUTCOME MEASURES: The number, duration, frequency, and peak-to-peak amplitude of train responses were analyzed and compared with postoperative facial nerve function. RESULTS: Trains were observed in 42 of 51 patients. Six of seven patients with high-amplitude trains more than 250 microV, and three of five patients with bomber-type high-frequency trains elicited during tumor dissection from the facial nerve or stretching the nerve, showed severe facial nerve dysfunction. On the other hand, seven of the nine patients with no trains also showed severe facial nerve dysfunction. CONCLUSIONS: The presence of high-amplitude or high-frequency trains elicited by surgical manipulation to the facial nerve seems to indicate a critical situation for the facial nerve. However, certain types of mechanical trauma resulting in severe facial nerve paralysis cannot be identified by train responses.

Clinical observations on coexistence of sudden hearing loss and vestibular schwannoma.

It has long been recognized that sudden hearing loss (SHL) may be a harbinger of vestibular schwannoma (VS). Among 192 VS patients who underwent operation in the Gruppo Otologico, Piacenza, Italy, from April 1987 to October 1995, the charts of 14 (7.3%) cases with a history of SHL were examined. SHL was the first symptom in 8 (4.2%) patients. Eight (57.1%) of 14 VS cases with SHL anamnesis had reported recovery of their previous hearing either totally or partially before establishment of tumor diagnosis. Five (35.7%) cases had recurrent bouts of SHL. SHL was observed less frequently in cases with large tumors (>3 cm). However, the frequency of SHL in patients with small tumors did not differ from that of medium-sized tumors. Awareness about coexistence of SHL and VS, as well as concomitant use of auditory brain stem response and magnetic resonance imaging, is crucial to rule out the diagnosis of VS in a patient with SHL.

Myringoplasty in children: factors influencing surgical outcome.

Age, size, and site of perforation, condition of the ear, status of the contralateral ear, grafting materials, and more are considered factors influencing the success rates in myringoplasties in children. The ambivalence in results is mainly due to nonhomogeneous patient groups. In an effort to compose groups as homogeneous as possible for analysis of influencing factors, a retrospective study of 51 pediatric myringoplasty cases (51 ears) was undertaken. All patients had perforations caused by simple chronic otitis media. The overall surgical success rate was 82.3% at 18 months, and for young (5 to 10 years) and older (11 to 16 years) children it was 77.2% and 86.2%, respectively. Anterior, central, and total perforations healed without significant differences. Outcome in unilateral perforations was better than bilateral: 96.9% and 55%, respectively (p < 0.01). Discharging ears (100%) healed better compared with dry ears (75%) (p < 0.05). Analysis of the literature also revealed significant difference in success rates of discharging and dry ears: 92.5% and 80.6%, respectively (p < 0.01). We conclude that, contrary to comments in the literature, discharging ears in children favor good outcome and they should be operated on regardless of age and site of perforation. However, in bilateral perforations results may not be so rewarding.

The cochlear aqueduct: an important landmark in lateral skull base surgery.

The cochlear aqueduct (CA) is used as a landmark in lateral skull base surgery. In this study anatomic relationships between the CA and adjacent neurovascular structures were examined by dissecting 32 temporal bones. Observations of the relationship of the external opening (EO) of the CA with the ninth, tenth, and eleventh cranial nerves, inferior petrosal sinus (IPS), and intrapetrous carotid artery (ICA) were noted. In addition to the distance of the EO of the CA to the vertical portion of the ICA, the entire length of the CA and the width of the EO were also measured. The ninth nerve was the only structure lodged at the EO of the CA in 34.4% of bones. However, in 40.6% of bones only the IPS crossed the EO of the CA, although the ninth nerve was situated just anteroinferiorly in the vicinity of the EO. In 15.6% of bones it was possible to observe both the ninth nerve and the IPS crossing the EO. In 9.4% of bones the EO of the CA was found to be occupied by the tenth and eleventh nerves. It was also observed that the ICA was located anteriorly on the same sagittal plane with the EO in 15.6% of bones. It was concluded that although in 90% of cases the EO of the CA was in close relation with the ninth nerve, other structures such as the IPS, the tenth and eleventh cranial nerves, and the ICA were also at risk during drilling in this area because of their intimate relationships with the EO of the CA.

Titration streptomycin therapy in Meniere's disease: long-term results.

As soon as the use of streptomycin was started for the treatment of tuberculosis, its ototoxic effect was discovered. Initial reports demonstrated that streptomycin was successful in reducing vestibular responses while preserving cochlear activity. Streptomycin sulfate has been used for almost half a century for the treatment of vertigo in patients with Meniere's disease. At the Gruppo Otologico, Piacenza, Italy, between 1987 and 1995 we treated 16 patients with either bilateral Meniere's disease or with Meniere's disease in their only hearing ear, adopting the titration streptomycin therapy protocol of Graham et al. Three patients with follow-up periods of less than 2 years were not included in this study. The ages of the patients ranged from 36 to 64 years with a mean of 49.2 years. The patients were observed for 2 to 8.8 years. The dose of administered streptomycin varied from 14 to 49 gm. Episodic vertigo was totally relieved in all of the patients after initial treatment, whereas hearing remained the same or was improved when compared with the pretreatment levels. Five of the patients experienced recurring vertigo during a period of 4 to 24 months after initial treatment. Oscillopsia persisted in two patients and ataxia in darkness persisted in another two patients. Hearing was unchanged in 14 ears, improved in 2 ears, and worsened in 4 ears at the last follow-up evaluation. The overall outcome indicated that intramuscular titration streptomycin therapy seems to be one of the most important therapeutic options in the treatment of disabling vertigo in patients with either bilateral Meniere's disease or Meniere's disease in an only hearing ear.

Complications and their management in tympanomastoid surgery.

Chronic diseases of the ear and their surgical treatment can endanger the delicate structures of the temporal bone in close relationship with the middle ear. The experience and expertise of the otologic surgeon, based on perfect knowledge of the complex anatomy of the whole temporal bone, are unfortunately built up partly through the management of complications encountered in tympanomastoid surgery and may require knowledge of basic neuro-otologic procedures. Paralysis and paresis of the facial nerve and labyrinthine, and dural and vascular injuries may have consequences not only in the final result of surgery but also in endangering the patient's life. All major complications are discussed and some possible treatments are proposed. Minor complications affecting the temporomandibular joint, the dura, the external auditory canal, and the bony canal wall are also covered, along with some suggestions on how to keep these consequences within reasonable percentages.

Meningiomas intrinsic to the geniculate ganglion.

Geniculate ganglion meningiomas are extremely rare lesions-only 14 cases have been reported in the literature. Two new cases of these tumors are described. On computed tomography and magnetic resonance imaging, both lesions appeared centered on the area of the geniculate ganglion, extending to the tympanic cleft and eroding the middle cranial fossa floor. The first case was treated through a middle cranial fossa approach. Because the tumor was so large in the second case, a subtotal petrosectomy was used. The authors review the literature to clarify the clinical and radiological characteristics of these tumors and their surgical treatment.

Pulsatile tinnitus as a rare presenting symptom of residual cholesteatoma.

Pulsatile tinnitus is an uncommon otological symptom, which often presents a diagnostic and management dilemma to the otolaryngologist. This symptom always deserves a thorough evaluation to avoid disastrous consequences from potentially life-threatening associated pathology. In most of the patients a treatable underlying aetiology can be identified. Frequent causes mentioned in the literature responsible for pulsatile tinnitus are benign intracranial hypertension syndrome, temporal bone paragangliomas and arteriovenous fistulae. Pulsatile tinnitus as a consequence of sigmoid sinus compression by a cholesteatoma has not been reported previously in the literature. Here a case of residual cholesteatoma with pulsatile tinnitus is presented, nine years after the first surgery.

Anatomical considerations of high jugular bulb in lateral skull base surgery.

In order to study high jugular bulb management in lateral skull base surgery, an anatomical study was conducted on 30 temporal bones by examining the relationship between the internal auditory canal (IAC) and the jugular bulb. The following parameters were measured: 1) Height of the jugular bulb (H)... distance between the level of jugular bulb dome and the line passing through the confluence of the sigmoid sinus with the jugular bulb (SS-JB), 2) Mastoid length (ML)... distance between the mastoid process and middle cranial fossa dura, 3) Distance between the most inferior part of the porus acousticus and jugular bulb dome (A), 4) Distance between the porus acousticus and SS-JB (B). The jugular bulb was defined as high when it occupied more than two thirds of (B). The incidence of a high jugular bulb was 23 per cent in this study. When the jugular bulb was high, the mean (H) and (A) were 9.4 +/- 1.9 mm and 2.7 +/- 0.5 mm, respectively. (H) was higher on the right side than on the left side. No statistically significant difference was found between small and large mastoids (t-test: p > 0.05). It was concluded that when a high jugular bulb was encountered during lateral skull base surgery, the jugular bulb position allows a very small working area inferior to the IAC. In these cases, a 3 or 4 mm depression of the jugular bulb is necessary in order to expose the lower cranial nerves. This can be accomplished by lowering the jugular bulb with the technique already described.

[Coexistence of vestibular schwannoma and glomus tympanicum tumor]. / Coesistenza di un neurinoma dell'acustico e di un tumore glomico timpanico.

Simultaneous occurrence of a vestibular schwannoma and a glomus tympanicum tumor has been reported only once in the international literature. The authors present a second case: a 72-year-old woman having a glomus tympanicum tumor and an ipsilateral lesion confined to the internal auditory canal, radiologically diagnosed as an acoustic neuroma. Due to the patient's age, symptoms, hearing threshold and the small size of both tumors the decision was made not to perform surgery. The patient will be regularly followed-up through computerized tomography and magnetic resonance imaging.

Internal auditory canal metastasis.

This report deals with 3 cases of internal auditory canal metastasis, an extremely rare lesion, few cases having been reported in the international literature. Since pre-operative diagnosis is fundamental in the planning of a correct therapeutic strategy, it is important that the neurotologist be aware of the possibility of their occurrence in this particular area. Metastasis can occur unilaterally as well as bilaterally; the latter being the case in 1 of the patients described herein. Correct pre-operative diagnosis is particularly difficult in patients in whom the primary tumour has not been detected at the time of identification of the lesion in the internal auditory canal. The only characteristic, specific of metastasis, is the presence of multifocal cerebral lesions. However, these were detected in only 1 of the present cases. On the contrary, in cases of a single metastasis, both magnetic resonance imaging and computed tomography usually fail to show any distinctive feature when compared to the most common tumours of the internal auditory canal (vestibular schwannomas and meningiomas). Bilateral metastases can also be misdiagnosed as neurofibromatosis type 2. Clinical data that should alert the clinician are: rapidly progressive sensorineural hearing loss, followed by onset of progressive facial nerve weakness. Radiotherapy and/or chemotherapy are the two main treatment modalities, while surgical removal is reserved for selected cases of a single metastasis. Albeit, due to the paucity of specific radiological and clinical characteristics, surgical removal is often necessary to reach the correct diagnosis, as occurred in 2 of the present patients.

[Lateral approaches to the clivus]. / Le vie d'accesso laterali al clivus.

Thanks to ongoing development in microsurgical techniques to treat the skull base some clivus lesions, considered inoperable until a few years ago, can now be removed with relatively low mortality and morbidity. The approaches available for the treatment of lesions in this anatomical area can be broken down into anterior and lateral. The latter offer the surgeon several important advantages such as better control over the main vascular structures and the possibility of opening the intradural space without coming into communication with the pharynx. By virtue of their extreme versatility, the lateral approaches may be used in combination in a single operation or can be performed as staged procedures. Each of the lateral routes, however, has its own advantages and drawbacks. These are presented during a brief description of each technique. The main factor in selection of approach is the anatomical limits of the approach itself. Generally speaking, the largest surgical field is offered by the most destructive approaches. Although they do cause such deficits as unilateral hearing loss, these approaches permit greatly improved control over the vital structures. Nevertheless, when such deficits exist prior to surgery, the morbidity of such approaches is negligible. The histological nature of the disease, the variable relationships with the dura, the main neurovascular structures and other factors should all be considered when deciding how to manage each case. The surgeon must, however, have the range of skills required to perform the diversity of approaches to the lateral skull base so as to provide the patient with the best possible care.

[Modified Body technique in the treatment of epithympanic cholesteatoma. Otologic group, Piacenza]. / La tecnica di Bondy modificata nel trattamento del colesteatoma epitimpanico. Gruppo Otologico, Piacenza.

The Bondy technique is a particular radical, yet conservative, treatment where the intact tympanic-ossicular system is preserved during the operation. This technique was initially introduced by Gustave Bondy in 1910 and has been used at the authors' center since December 1983 with a few modifications. In the twelve years from December 1983 to December 1995 69 cases (66 patients) were treated with this technique: 5.6% of all chronic cholesteatomatose otitis surgically treated during that period. The following indications were applied: purely epitymapnic cholesteatoma, average transmission gap equal to or lower than 25 dB and intact bone chain. During the follow-up no signs of recurrent cholestatoma were found. The average post-operative transmission gap was greater than 25 dB in only 5 of the 54 cases with at least one year of follow-up. When used in selected cases, the modified Bondy technique can be considered an excellent option in the treatment of epitympanic cholesteatoma, making it possible to maintain the good pre-operative hearing without requiring a second operation.

[Cerebrospinal fluid leak after translabyrinthine approach in acoustic neuroma excision]. / La liquorrea come complicanza della via translabirintica nel trattamento del neurinoma dell'acustico.

Cerebrospinal fluid (CSF) leak is one of the most dangerous complications that can arise in cases of acoustic neuroma removal. It increases the risk of meningitis, requires longer postoperative recovery and often requires revision surgery. A retrospective analysis was performed on all cases of acoustic neuromas which had undergone translabyrinthine surgery at the Gruppo Otologico, Piacenza, Italy, between April 1987 and December 1997, in the aim of finding the causes of postoperative CSF leaks. The causes found were high pneumatization of the temporal bone and improper execution of some surgical steps. The technique has presently been modified on the basis of the experience gained from cases of CSF leaks. By scrupulously applying these modifications, from July 1994 to December 1997, a total of 160 patients were consecutively treated using the translabyrinthine approach without a single case of postoperative CSF leak. Routine use of this modified technique can and must lower the percentage of CSF leaks after a translabyrinthine surgery to nearly 0%.

[Treatment of residual acoustic neurinomas]. / Il trattamento dei neurinomi dell'acustico residui.

Generally the main objective of acoustic neurinoma (AN) surgery is to totally remove the tumor associated with minimum morbidity. Nevertheless, in some cases residual tumor fragments are intentionally or accidentally left in place. These residues can lead to new growth. The present study provides a retrospective analysis of 14 cases of residual AN have undergone surgery at the Otology Group in Piacenza from 1987 to 1999. All these patients had previously undergone at least one retrosigmoidal exeresis although only one had been performed at the Otology Group. All patients except 1 were affected by anacusia at the time of surgery. The list of post-operative deficits included 2 hemipareses, 3 irreversible facial paralysis with consequent corneal opacity in 2 cases, 1 dysmetria and 1 paralysis of the abducent nerve. The patients had also undergone the following additional treatments: 1 emergency revision to drain a cerebellar hematoma, 3 ventricle-peritoneal derivations, 1 double application of stereotactic radiotherapy and 2 surgical procedures for facial plasty. Ten cases underwent the revision surgery at the Otologic Group using a translabyrinthine approach and 4 using a transcochlear approach. Tumor removal was deemed complete in all cases. The sole post-operative complications were a subcutaneous hematoma at the point where abdominal fat was removed and a temporary paralysis of the abducent nerve. Post-operative hospitalization was an average of 6.9 days. Analysis of the results showed that AN must be operated at selected centers in order to reduce the post-operative neurological deficit and the percentage of residual tumor. It also indicated that the retrosigmoid approach has a higher risk of accidentally leaving tumor residues than the other approaches. Finally, in the presence of a residual AN, the translabyrinthine approach offers the greatest advantages.