Acoustic Tumors: Preoperative Measurement and Correlation with Postoperative Facial Nerve Function

Abstract

The cases of 67 patients consecutively operated on for acoustic tumors are reported. Preoperative records consist of tumor size and the position of the fourth ventricle on computerized tomography (CT) scans. An analysis is made of the immediate postoperative and current function of the facial nerves. There is a statistically significant relationship between the number of weak or paralyzed seventh nerves and displacement of the fourth ventricle (P less than .05). It is now possible to accurately measure acoustic tumors on preoperative CT scans. The position of the fourth ventricle can also be clearly seen. The current standard of diagnosis and management of acoustic tumors should include a cursor measurement of tumor size on CT scan and a notation of the position of the fourth ventricle. Adoption of this method of reporting will permit meaningful evaluation of treatment for acoustic tumors. This analysis illustrates the importance of accurate measurements in reporting and evaluating surgical results.

Radiological and Clinical Factors Predicting the Facial Nerve Outcome following Retrosigmoid Approach for Large Vestibular Schwannomas (VSs)

“…14 Previous studies have demonstrated that the size and staging of the tumor influence postoperative facial nerve outcome. [10][11][12][13][14][15] Our study also confirms that large tumors correlate with poor facial nerve outcome. Similarly, in their series of 129 patients, Lalwani et al 21 describe the facial nerve outcome at 1 year or greater following surgery as being inversely correlated with the size of the tumor (p < 0.02).…”

“…These factors include size, volume, staging of the tumor, histological features, clinical presentation, tumor extension, changes in the internal acoustic meatus, radiological features, operative approach, extent of resection, and experience of the surgeon. [10][11][12][13][14][15]17,18 A patient's facial nerve function after VS surgery is one of the major determinants of morbidity and quality of life following the surgery. 19,20 Our study aimed to identify the clinical and radiological factors that can be used to predict the facial nerve outcome after surgery.…”

“…[3][4][5][6][7][8][9] Size and staging of the tumor are now well recognized factors influencing the postoperative facial nerve outcome. [10][11][12] Moreover, the effect on facial nerve outcome of several other factors such as histological features, clinical presentation, extrameatal tumor extension, bony changes in the internal acoustic meatus, and radiological features has been documented. [11][12][13][14][15] However, the majority of these studies lacked uniformity in terms of surgical approaches, operating surgeons, techniques of tumor excision, and methods of facial nerve preservation.…”

“…[10][11][12] Moreover, the effect on facial nerve outcome of several other factors such as histological features, clinical presentation, extrameatal tumor extension, bony changes in the internal acoustic meatus, and radiological features has been documented. [11][12][13][14][15] However, the majority of these studies lacked uniformity in terms of surgical approaches, operating surgeons, techniques of tumor excision, and methods of facial nerve preservation. The aim of our study was to identify various radiological and clinical factors that correlate with the facial nerve outcome after VS surgery using the retrosigmoid approach.…”

Diagnosis of Cerebellopontine Angle Tumors

“…It has been shown that there is justification for early excision of acoustic neuromas in order to reduce the mor bidity and mortality and to improve chance of preserving the facial nerve [10] and hearing [11], Although BAEP and MRI have made the diagnosis of CPAT more effi cient, some patients are still presenting with large tumors because CPAT often remain asymptomatic for a long time. In our series, the mean delay between the first and the presenting symptom was 4 years.…”