D. G. Hardy

The outcome of radical surgery and postoperative radiotherapy for squamous carcinoma of the temporal bone.

Objectives/Hypothesis: The objective was to analyze the clinical data and outcome of all the patients treated surgically for squamous carcinoma of the temporal bone in a tertiary referral department of skull base surgery over a 20‐year period.

Strategy and benefits of acoustic neuroma searching

Advances in audiological, radiological and microsurgical techniques have enabled otologists to diagnose and excise very small acoustic tumours with a low morbidity and mortality. Is this cost effective? In an attempt to answer this question, an analysis of 66 cases of surgically treated acoustic neuromas is presented. This represents part of a series of skull base procedures carried out at Addenbrookes Hospital over the last five years. As a result of this work an investigative protocol is suggested. By studying the relative morbidity of early and late surgical intervention in these cases, and by costing the exercise, the justification for early diagnosis and treatment is presented both in financial and human terms.

What is the effect of translabyrinthine acoustic schwannoma removal upon tinnitus

A series of 129 patients who had undergone translabyrinthine removal of a unilateral acoustic schwannoma completed a postal questionnaire about pre- and post-operative tinnitus. A simple grading system was devised from which it was possible to determine the likely outcome of translabyrinthine acoustic schwannoma surgery upon tinnitus. The results have been analyzed in detail, and as a result it is possible to advise a patient undergoing this form of surgery that if they have no tinnitus pre-operatively they are unlikely to develop it, and if they do it will not be severe enough to significantly affect their quality of life. If they have mild or moderate tinnitus it is most likely to stay the same, or become less intense. If a patient has severe tinnitus it is very likely to improve and not affect their future quality of life.

Clinical correlates of acoustic neuroma morphology

Thirty-eight patients with vestibular schwannomas were reviewed. A correlation was found between tumour morphology and clinical presentation. Based on our knowledge of the variability in the neurilemmal-neurologlial junction and therefore the site of origin of these tumours in relation to the internal auditory canal, a classification into three different appearances on magnetic resonance imaging was possible. Dumbbell shaped tumours (21 per cent) represented laterally arising schwannomas, lollipop shaped tumours (18 per cent) were medially arising and cone shaped tumours (61 per cent) were the more common intermediate form. Patients with laterally arising dumb-bell shaped tumours were more likely to present early with hearing loss and had smaller tumours than patients with medially arising lollipop shaped ones. The relatively well preserved hearing in patients with medially arising tumours made them more likely to present at a later stage with signs of trigeminal compression, cerebellar dysfunction and raised intracranial pressure.

Hearing preservation in solitary vestibular schwannoma surgery using the retrosigmoid approach

The results of 50 cases of vestibular schwannoma surgery with hearing preservation performed by the retrosigmoid approach at Addenbrookes Hospital, Cambridge, during a 10-year period are presented. The hearing-preservation rate, using audiometric criteria set by others as “serviceable hearing” (Wade PJ, House W. Otolaryngol Head Neck Surg 1984;92:1184-93; Silverstein H, et al. Otolaryngol Head Neck Surg 1986;95:285-91; Cohen NL, et al. Am J Otol 1993;14:423-33) was 8% (4 of 50 cases). When the more stringent selection criteria of near-normal hearing and reporting criteria of socially useful hearing preservation (pure-tone average < 30 dB/speech discrimination score > 70%) is used, the hearing-preservation rate is 4.8% (1 of 21 cases). The only preoperative factor that may predict a favorable hearing-preservation outcome is normal auditory brain stem response morphology (Fishers exact 2-tailed test, P < 0.001). The number of suitable candidates for hearing-preservation surgery are few. Reasonable indications for attempted vestibular schwannoma surgery with hearing preservation are discussed.

Facial nerve recovery after acoustic neuroma removal

A retrospective analysis of 76 patients who underwent acoustic neuroma removal is reported. Facial nerve function prior to surgery and tumour size are assessed with respect to final facial nerve recovery and the need for surgical rehabilitation. Both pre-operative facial weakness and tumour size greater than 2.5 cm. are shown to be predictive factors of poor facial nerve recovery. Multiple surgical rehabilitative procedures are often required when inadequate function and/or cosmetic results are obtained. Primary nerve repair and facial-hypoglossal anastomosis give better rehabilitative results than dynamic and static procedures. The association of tumour size greater than 2.5 cm. with increased risk of poor facial recovery re-emphasizes the need to detect and remove acoustic neuromas at an early stage.

Audio-vestibular findings in meningioma of the cerebello-pontine angle: a retrospective review

The aim of this study was the determination of the incidence of symptoms of audio-vestibular dysfunction and of abnormalities on audio-vestibular testing in patients found to have a unilateral meningioma of the cerebello-pontine angle (CPA). The case notes of 25 patients diagnosed with unilateral, sporadic and histologically proven CPA meningioma were retrospectively reviewed. The age range of this series was 31-71 years, with a mean age of 50 years. Two patients were male (eight per cent) and 23 were female (92 per cent). The mean length of history was 44.7 months. The distribution of tumour size was skewed toward larger tumours, with 15 cases (60 per cent) having tumours with a maximum diameter greater than 3.5 cm on imaging. Pure tone audiometry was normal in five cases (20 per cent), and no patients exhibited the high frequency sensorineural hearing loss that is characteristic of vestibular schwannoma. Speech audiometry was normal in 50 per cent of cases. Caloric testing was abnormal in 77 per cent of the 18 cases tested, whilst auditory brainstem responses (ABR) were abnormal in 100 per cent of the 18 cases who had sufficient hearing for this test to be possible. The presence of normal audiometry in patients with a proven CPA lesion indicates that, if in a protocol for investigation, asymmetry of hearing is mandatory then some pathology will be missed. Any suspicion of a CPA lesion warrants investigation even in the absence of hearing loss. The investigation of choice for the identification of CPA lesions has become magnetic resonance imaging (MRI). If this technique is not available then this study indicates that ABR is a suitable and sensitive investigation. It should be borne in mind however that the data in this study has been derived from a series of predominantly large tumours, and the sensitivity of ABR to smaller CPA meningiomata may fall, as is the case for vestibular schwannoma.

Cavernous haemangioma of the internal auditory canal.

Cavernous haemangiomas are rare lesions of the cerebello-pontine angle that can mimic the more commonly occurring vestibular schwannoma. A case report involving a patient with a cavernous haemangioma of the internal auditory canal (IAC) highlights this as a diagnostic possibility for lesions of the IAC by comparing and contrasting the clinical and radiological findings with the more commonly occurring vestibular nerve and facial schwannomas. Symptoms such as hearing loss and facial paralysis that are disproportionate to the size of the lesion or fluctuate with hormonal changes such as those seen in pregnancy are suggestive of haemangioma. Radiological imaging demonstrating a lesion enhancing with gadolinium and containing areas of calcification is also suggestive of haemangioma. It is important to consider the possible diagnosis of haemangioma as early recognition of this entity may improve the chances of preserving the functional integrity of the facial nerve.

Squamous Cell Carcinoma of the Temporal Bone: Clinical Outcomes From Radical Surgery and Postoperative Radiotherapy

Objective To review the treatment of squamous carcinoma of the temporal bone at a regional skull base unit for the period 1982–2012. Study Design Retrospective case review. Setting Tertiary referral center. Patients Sixty patients with primary squamous carcinoma of the temporal bone. Interventions Multidisciplinary team approach including surgical resection, reconstruction, and postoperative radiotherapy. Main Outcome Measures Disease-specific survival, overall survival. Results The 5-year disease-specific survival for the whole cohort was 44% (CI, 37%–51%). Multivariable analysis revealed nodal status, poorly differentiated squamous cell histology, and carotid involvement to be poor prognostic indicators. Conclusion Although the survival figures in this series are comparable with the best outcomes from other units, our experience would suggest improvements can still be achieved by reconsidering the selection of patients for neck dissection and temperomandibular joint excision in early stage disease. We also conclude that postoperative radiotherapy should be delivered to all patients, including surgical salvage cases who may have received previous irradiation. Finally, the minority of patients with poor prognostic features should be offered a more palliative therapeutic approach.

The surgical management of patients with glomus tumours of the skull base

Total surgical excision is the only treatment modality that offers a cure for patients with glomus tumours of the skull base. The vascularity, inaccessibility and frequently extensive local spread, all contribute to the difficulties encountered in the management of patients with these complex lesions. Owing to the rarity of skull base glomus tumours, experience in their management can only be attained over long periods of time. We describe the surgical management of 20 patients with large glomus tumours of the skull base treated by an otoneurosurgical team over an 11-year period. Overall, 70% of patients had an excellent outcome, 10% a good outcome and 20% a poor outcome at a mean follow-up of 3.1 years. Poor outcomes were due to severe facial nerve palsies in two cases, and poorly accommodated palsies of the bulbar cranial nerves in a further two patients. The management of postoperative neurological deficits is discussed in detail. We conclude that in the majority of patients with skull base glomus tumours, complete surgical excision can be safely achieved.