Brain shift is central to the pathogenesis of intracerebral haemorrhage remote from the site of the initial neurosurgical procedure

Abstract

Intracerebral haemorrhage remote from the site of surgery is an uncommon and poorly understood complication after neurosurgical procedures. Although patients under anticoagulant therapy or with perioperative elevated blood pressure are usually considered potentially at high risk of postoperative intracerebral haemorrhage, the aetiology is still unclear for patients without these predisposing factors. In this paper, we suggest that brain shift, unavoidably occurring during all neurosurgical procedures, might play a central role in the aetiology of postoperative remote intracerebral haemorrhage. Brain shift is mainly caused by gravity, aggressive intraoperative dehydration, and cerebrospinal fluid aspiration. Brain shift produces stretching and transient occlusion of the corticodural bridging veins draining into the peripheral dural sinus. Consequently, venous infarcts occur in the venous drainage territories and haemorrhagic transformation results when perfusion is re-established within ischemic tissue. To minimize brain shift and consequent risk of remote intracerebral haemorrhage, we recommend avoiding the use of hyperosmotic agents and cerebrospinal fluid drainage systems during neurosurgical procedures. Moderate head elevation during and immediately after surgery may improve cerebral venous drainage and reduces the risks of this life-threatening complication.