Factors Influencing the Development of Peritumoral Brain Edema in Menigiomas

In a series of 43 patients with intracranial meningioma, we retrospectively analysed factors influencing the development of peritumoral brain edema(PTBE). The extent of this was measured by the Edema Index(EI), obtained from the size of the meningioma and associated PTBE on a T2-weighted magnetic resonance image. We evaluated the relationship between EI and certain factors that may play a role in the development of PTBE ; namely age, size, location, and histology of the tumor, and its vascular supply(intrinsic cerebral artery or meningeal artery). Tumors in the frontal and sphenoid ridge regions tended to be associated with more extensive PTBE than these in the parietal, occipital, and infratentorial regions(p<0.05). In particular, the extent of infratentorial meningioma-associated PTBE tended to be slight. Histologically, PTBE associated with meningotheliomatous and transitional meningiomas tended to be more extensive than that associated with the fibroblastic meningiomas(p<0.05). On angiography, it was seen that for meningiomas supplied by intrinsic cerebral artery(internal carotid or veterbral artery only, or in conjunction with the meningeal artery), correlation with severe PTBE was higher than for those supplied by the meningeal artery only(p<0.05). We concluded, therefore, that location, histology, and vascular supply from the intrinsic cerebral arteries were the factors influencing PTBE.

Infectious Intracranial Aneurysms

The management of infectious intracranial aneurysm, either by antibiotics alone or by surgery plus antibiotic therapy, remains controversal. Some authors have recommended initial treatment with antibiotics, plus serial angiography, and consider surgery only in cases where aneurysm enlargement during antibiotic treatment or persistence after treatment is documented. Due to the unpredictable rebleeding rate and high morbidity and mortality rate associated with rebleeding, others have argued for prompt surgical intervention. We report a case of surgically treated infectious intracranial aneurysm located distal to the trifurcation of the right middle cerebral artery. During the course of high-dose antibiotic therapy, rupture and rapid enlargement occurred ; after the operation, the patient underwent cardiac surgery and is at present in good health.

The Effect of Barbiturate in Brain Protection under Mild Hypothermia During Temporary Vessel Occlusion in Aneurysm Surgery

Temporary vessel occulusion is a useful technique which facilitates aneurysmal dissection and clipping, and reduces the risk of intraoperative aneurysal rupture; It may, however, result in postoperative stroke, and many authors have therefore used various agents for brain protection. Among these, barbiturate is well known. This study was undertaken to retrospectively review the effect of barbiturate on brain protection during short periods of ischemia. It involved patients with 146 anterior circulation aneurysms, who were divided into two groups: 43 who received intraoperative barbiturate burst suppression with sodium thiopental during temporary vessel occlusion and the remaining 103, who did not. Doses of thiopental 5mg/kg, usually singly or occasionally repeated at 10-mimute interval, were administered. All patients underwent general anesthesia using volatile isoflurane; mild hypothermia(32-34degreesC), mild hypocarbia(30-35mmHg), and normotension of 110-130mmHg were noted prior to permanent clipping, and mild hypertension(130-150mmHg) after clipping. In some cases, intraoperative scalp electroencep-halography was monitored. Clinical, radiological, and overall infarction were assessed postoperatively, and statistical analysis was perfomed. With regard to Hunt-Hess grades, number of episodes of occlusion, duration of temporary clip application lasting less than 13 minutes, and period of post-subarachnoid hemorrhage, no significant differences were seen between the two groups. Patients in whom barbiturate burst was suppressed showed a 4-hours delay in mean anesthetic recovery time, and after thiopental sodium was injected intravenously, systolic and mean arterial pressure(MAP), averaging 10-20mmHg, were lowered than in those without this suppression. In conclusion, we had found that under mild hypothermic anesthesia involving less than 13 minutes of temporary vessel occlusion, protection of the brain by barbiturate was not beneficial.