Vascular tunnel construction in the treatment of severe brain swelling caused by trauma and SAH. (evidence based on intra-operative blood flow measure)

Abstract

Decompressive craniectomy with durotomy, is possible as a last resort therapy for severe traumatic brain swelling. Although the method successfully diminishes the ICP, partial or total vascular insufficiency occurs in the herniated part of the brain. The actual cause of the insufficiency is most likely due to the compression of the cortical veins and arteries supplying the herniated brain, caused by shearing and pressure forces between the dural edge and brain tissue. Furthermore venous congestion may induce edema in the protruding parts of the brain, thus further compromising neurone viability. The new surgical technique consists of a stellate type durotomy and the creation of a vascular tunnel around the main cortical veins and arteries, with the aim that the vessels do not become compressed by the dural or bone edge. The effect of the novel vascular tunnel technique was proven by measuring the blood flow of the protected and nonprotected veins with Doppler UH, intra-operatively. In the last two years 28 patients were operated on with this method. One case of edema was caused by SAH. All were in severe GCS 3 or GCS 4 status, with more than 30 mmHg ICP. In comparison with the traditional surgical and nonsurgical treatment, where the reported mortality rates are 80%-90% in these severe cases the mortality rate was reduced to 40%, and recovery (GOS 4, 5) rate also increased significantly. With this technique the ICP was significantly reduced and further edema and vascular insufficiency was prevented. This was due to protection of the arterial circulation and venous drainage of the herniated part of the brain, by the formation of a vascular tunnel at the durotomy edges.