✓ This communication outlines the development of aneurysm clips, from those originally used by Walter Dandy to those in use today. The history is rich, with many contributions from neurosurgical pioneers and innovators. As a result, the modern neurosurgeon has a wide selection of biocompatible aneurysm clips from which to choose, clips that have known closing pressures and various sizes and shapes, as well as a selection of clip applicators that do not obstruct the surgical field.
Deon F. Louw, Taro Kaibara and Garnette R. Sutherland
Deon F. Louw, Wilson T. Asfora and Garnette R. Sutherland
In this communication the authors outline the development of aneurysm clips from those originally used by Walter Dandy to those currently in use. The history is rich in contributions from neurosurgical pioneers and innovators. As a result, the modern neurosurgeon has a wide selection of biocompatible aneurysm clips with known closing pressure, of variable sizes and shapes, and a selection of clip applicators that do not obstruct the surgical field.
Martin Rohringer, Garnette R. Sutherland, Deon F. Louw and Anders A. F. Sima
✓ The incidence of intracranial meningioma in Manitoba, Canada, was reviewed from 1980 through 1987. During that time, 193 tumors were diagnosed, with a male:female ratio of 1:2. This occurrence corresponded to crude incidence rates of 2.3/100,000 for all meningiomas and 0.17/100,000 for malignant meningiomas. Among malignant meningiomas, the male:female ratio was 1:1. The age-specific annual incidence rate increased with age up to the eighth decade where it peaked at 8.4/100,000. The distribution of histopathological subtypes was: 74 meningotheliomatous (38%), 64 transitional (33%), 14 malignant (7%), 14 fibroblastic (7%), seven psammomatous (4%), four angioblastic (2%), and 16 unknown (8%). The diagnosis of malignant meningioma was based on the World Health Organization criteria, with only Grade III and IV tumors included in this subtype. Clinical features did not allow for differentiation of benign from malignant neoplasms. Individuals with malignant tumors were, however, more likely to suffer paresis (50%) and less likely to be without deficit (14%) than their benign counterparts. The radiographic appearance of “mushrooming” was observed only in patients with malignant meningioma. All malignant tumors showed evidence of peritumoral edema; however, none exhibited calcification. During the 8-year study interval, the tumor recurred in 10 (71%) of the 14 patients with malignant meningioma. Tumor recurrence was accompanied by dedifferentiation from a more benign histology in four patients (2% of the total material).