Analysis of results of complete and partial removal of acoustic neuromas.

Out of a total of 3,265 brain tumours verified in Professor Olivecrona's clinic up to December 31, 1946, there were 305 unilateral acoustic neuromas, (9-30%). In addition six bilateral acoustic neuromas and four neuromas of the trigeminal nerve were verified. Looking back over 24 years, Professor Olivecrona remarked on the improvements in technique which lightened the surgeon's burden. The realization that few patients with acoustic tumours survive more than three or four years if some considerable portion of the tumour has been left behind, led to the adoption of total extirpation as the method of choice, though it carries considerably more risk than more conservative measures. It had to be noted that the early diagnosis of these tumours had not improved much as time passed, for most of the Stockholm patients came to operation in a late stage of development, and not a few were blind, or nearly so. Only once was a very early tumour found at operation in a patient with unilateral deafness, an enlarged porus, and symptoms suggestive of Meniere's disease. Of the 305 cases, two cases were not operated upon (one a child 15 months old), and three had decompressions only. In previous communications, Olivecrona had divided the incomplete removals into two groups: (l) Intracapsular; (2) subtotal. But there was found to be no essential diffeience in the follow-up histories, and further, since the border-line between the two is narrow, Olivecrona decided to abandon this classification, and to reduce the operation to