1. Since Symonds in 1923 and 1924 drew attention to the relationship between subarachnoid haemorrhage and leaking intracranial aneurysms,-interest has been centred in the aetiology of this condition rather than in its treatrWent. Customarily spontaneous subarachnoicl' haemorrhage is treated by rest and quiet. Yet with such conservative management the mortality rate in most general hospitals ranges between 50 and 60%0, while only 15 to 30°" of sufferers make a satisfactory recovery (Table 1). Spontaneous subarachnoid haemorrhage is thus a deadly and treacherous condition, and one which offers a challenge to surgery;Recently I; drew attention to the possibilities of surgical treatment,1950
2. Presented at the combined meeting of the Society of British Neurological Surgeons and the Sociedad Luso-Espaniola de Neurocirurgia at Madrid on,1951
3. in greater detail the operative management of leaking intLacranial aneurysms, for these are lesions responsible for at least three-quarters of the cases of ubarachnoid haemorrhage,1941
4. a 30% mortality Of the 50 patients, 33 made good recoveries, eight rate in 20 cases. Rogers (1949), however, performed recovered with an appreciable disability (total common carotid ligation in six cases with only one recovery rate, 82%) and only nine died (mortality death;ligation; Krayenbuhl,1946
5. although hazardous, permits of more precise treat-These 50 cases of leaking aneurysm were recogment. The local measures available once the nized as a result of arteriography or operation in 69 aneurysm has been exposed range from wrapping consecutive cases of recent subarachnoid haemorhammered muscles around it (Dott, 1933), to rhage admitted to the Neurosurgical Unit of the incising the aneurysm and packing muscle into its Dunedin Hospital from various hospitals in New interior (McConnell, 1937), clipping the neck of the Zealand. Half of these cases had experienced more aneurysm (Dandy, 1938), trapping the aneurysm by than one attack of bleeding, and most were referred occluding the artery on either side of its neck within less than a week of the last attack. The (Fincher, 1939), to shrivelling the aneurysmal sac symptoms shown were similar to those usually with diathermy (Dandy, 1944). At least three cases reported in spontaneous subarachnoid haemorrhage