Cerebral blood outflow maintenance during intracranial hypertension

Abstract

Method and apparatus for detecting and treating cerebral blood vessel collapse (54) during intracranial hypertension or vasospasm by affecting cerebral venous outflow pressure (61). Venous collapse is diagnosed by lowering jugular venous bulb pressure (61) and detecting significant, progressively increasing gradient between it and ICP (60). Rising jugular venous pressure initially the collapse is terminated and then ICP starts to increase. Increasing jugular venous pressure opens collapsed vascular segments by increasing intravascular pressure. There is no increase in ICP if jugular venous pressure is maintained below value that affects ICP. During life-threatening vascular collapse caused by a plateau wave or vasospasm venous outflow pressure is temporarily increased to a level necessary to terminate collapse regardless of ICP. This is accomplished by venous occlusion catheter placed into dominant jugular vein. Catheter has highly compliant inflatable balloon operating like Starling resistor for venous outflow pressure control. Quick control of venous pressure is achieved by withdrawing/injecting fluid through catheter tip. Operation catheter is controlled by controller, which also measures ICP and possibly CBF, S.sub.jv O.sub.2. Alternative venous outflow control measures are possible.