No abstract

The authors have reported a case of a craniopharyngioma removed by the interhemispheric translamina terminalis approach, and the postoperative development of a subcortical hematoma. We suspected that the cause of the subcortical hematoma was dividing the bridging veins and applying a retractor over them. In this paper, we report our experimental study, using dogs and monkeys, to evaluate the effect of cutting the vein and applying a retractor over it. The incidence of a subcortical hematoma was highest (60%) when the veins were cut and the retraction was applied. Vein occlusion only did not cause hematoma to develop, and the retraction alone caused 13% of the hematomas. This clearly indicated that the clinical case reported in Part I developed the subcortical hematoma postoperatively because the frontal bridging vein was cut and a retractor was applied for 60 minutes over the cut vein.

Various techniques and approaches have been developed to minimize invasion in skull base surgery. If the sigmoid and transverse sinuses could be divided safely, surgeons could have better surgical access without much retraction of the brain. However, it is currently believed that these sinuses contain important routes of venous drainage from the brain and that, if they are sacrificed, severe brain swelling would follow.Recently, surgical techniques were reported by which the sigmoid and transverse sinuses could be divided. [1][2][3] The authors found it safe to divide the sigmoid sinus and proposed that the divided transverse sinus be closed on completion of the operation. Generally, however, it is still considered risky to ablate these sinuses to provide access to skull base and brain.We performed the present study to establish the safety of sacrificing these sinuses experimentally in monkeys, since it is well known that the venous drainage of the monkey's brain is quite similar to that in humans. The purpose of the present study was to measure the effect of sacrificing the sigmoid and transverse sinuses on sinus pressure, regional cerebral blood flow (rCBF), and cortical motor evoked potentials(MEP). MATERIALS AND METHODSJapanese monkeys (Macacafascata) weighing 5 to 6 kg were used for the experiments described. After induction with ketamine and atropine at doses of 5 and 0.2 mg/ kg, respectively, general anesthesia was established with thiamylal (10 mg/kg) given intravenously, and an endotracheal tube was inserted. Serial blood gas measurements were taken throughout the surgery and partial arterial carbon dioxide pressure was kept within the normal physiologic range (35 to 40 mmHg) by giving room air or oxygen (2 ml/min). Blood pressure (femoral artery, A line) was also maintained around the level of 90 to 105 mmHg. While in the prone position, suboccipital craniectomy was performed after a linear skin incision was made. The craniectomy extended across the transverse and sigmoid sinuses. A parietal craniectomy was also performed and a part of the dura was opened to measure MEP and rCBF at the prefrontal motor cortex. This craniectomy also allowed inspection of the brain surface for venous congestion. In two monkeys in which bilateral transverse sinuses are occluded and the pressure was measured in the

No abstract

Seventeenout of 330 patients with hypertensive intracerebral hemorrhage developed a recurrence of some kinds of cerebrovascular disease. The type of disease, age, number of occurrences, interval between occurrences and prognosis in these 17 cases were analysed. Risk factors for recurrence were also verified.Twelve out of the 17 cases developed intracerebral hemorrhage again. The interval until the recurrence was most frequently less than one year; but with some cases even more than five years elapsed. Cases in which the recurrence occurred on the contralateral side were the most serious.The prognosis was not significantly influenced by hypertension. However, hypertension with hypoproteinemia was an important prognostic factor.The authors suggest that a high-protein diet with control of hypertension would decrease the incidence of recurrent intracerebral hemorrhage.