Criteria for Surgical Treatment of the Intracranial Hypertension Caused by Cerebral Infarction. Summary of the Doctoral Thesis

Abstract

Despite significant progress in prophylaxis, diagnostics and treatment of stroke achieved over the last decades, it is still one of the most frequent cause of disability and death worldwide. Thesis „Surgical treatment criteria of intracranial hypertension caused by cerebral infarction” is dedicated to one of the topicality in fields of neurology and neurosurgery, i.e. treatment of malignant middle cerebral artery (MCA) stroke. As known, malignant MCA stroke is the most devastating form of stroke which occurs roughly in 10% of all ischaemic strokes. Standard management modalities for acute ischaemic stroke and additional measures available at the intensive care unit have not proven efficiency – within the first week 80% of patients die due to intracranial hypertension and brainstem herniation but survivors remain severely disabled. Due to limitations of therapies, decompressive craniectomy has been proposed as a surgical option. The rationale of this therapy is to create compensatory space to accommodate the swollen brain, thus preventing intracranial hypertension and brainstem herniation. By now there are results of five international randomised controlled trials published worldwide involving a total of 268 patients. Trials provided convincing general data on potential benefits of decompressive craniectomy. Despite potential benefits, unfavorable outcome after surgery is still often, due to lack of specific, statistically significant criteria that would allow to justify the choice of surgery and predict its effectivness in more detailed way. The aim of our study was to clarify the amount of middle cerebral artery stroke patients who could be considered as potential candidates for decompressive craniectomy and to determine science-based criteria with prognostic value for the clinical outcome after use of decompression craniectomy. Retrospective analysis of 748 patients with diagnosis of middle cerebral artery stroke was performed. Accordingly to the severity of symptoms, patients were divided into two groups of severe and mild stroke. Groups were subdivided depending whether there was or there was no radiological and/or clinical evidence of space-occupying edema. All subgroups were analyzed in terms of mortality, cause of death. Fourty-four patients meeting the inclusion criteria were randomized prospectively to either decompressive craniectomy or best medical treatment groups. Cerebral infarct volume and NIHSS scores at time of enrollment were measured in every case. Clinical outcomes were evaluated at 6 and 12 months. Primary outcome measure was overall survival and functional outcome. In surgical arm subgroup analysis investigating impact of age, cerebral infarct volume and NIHSS scores on outcome was performed as secondary measure. Our research suggests that decompressive craniectomy is potentially considered in approximately 7% of all middle cerebral artery stroke patients. Assessing the prognostic value of demographic and clinical criteria, it was found that patient age and cerebral infarct volume are criteria with statistically significant prognostic value for the clinical outcome after surgery. Age over 60 and cerebral infarct volume over 390 cc are associated with unfavorable outcome after surgery. Initial NIHSS score did not prove to have predictive value on outcome after surgery. Taking into account the results of the research, it has become possible to predict the potential proportion and amount of middle cerebral artery stroke patients who are potential candidates for surgery. It has become possible to predict clinical outcome after surgery with higher precision than previously in malignant MCA stroke patients.