Angelos G. Kolias

Continuous determination of optimal cerebral perfusion pressure in traumatic brain injury

Objectives: We have sought to develop an automated methodology for the continuous updating of optimal cerebral perfusion pressure (CPPopt) for patients after severe traumatic head injury, using continuous monitoring of cerebrovascular pressure reactivity. We then validated the CPPopt algorithm by determining the association between outcome and the deviation of actual CPP from CPPopt. Design: Retrospective analysis of prospectively collected data. Setting: Neurosciences critical care unit of a university hospital. Patients: A total of 327 traumatic head-injury patients admitted between 2003 and 2009 with continuous monitoring of arterial blood pressure and intracranial pressure. Measurements and Main Results: Arterial blood pressure, intracranial pressure, and CPP were continuously recorded, and pressure reactivity index was calculated online. Outcome was assessed at 6 months. An automated curve fitting method was applied to determine CPP at the minimum value for pressure reactivity index (CPPopt). A time trend of CPPopt was created using a moving 4-hr window, updated every minute. Identification of CPPopt was, on average, feasible during 55% of the whole recording period. Patient outcome correlated with the continuously updated difference between median CPP and CPPopt (chi-square = 45, p < .001; outcome dichotomized into fatal and nonfatal). Mortality was associated with relative “hypoperfusion” (CPP < CPPopt), severe disability with “hyperperfusion” (CPP > CPPopt), and favorable outcome was associated with smaller deviations of CPP from the individualized CPPopt. While deviations from global target CPP values of 60 mm Hg and 70 mm Hg were also related to outcome, these relationships were less robust. Conclusions: Real-time CPPopt could be identified during the recording time of majority of the patients. Patients with a median CPP close to CPPopt were more likely to have a favorable outcome than those in whom median CPP was widely different from CPPopt. Deviations from individualized CPPopt were more predictive of outcome than deviations from a common target CPP. CPP management to optimize cerebrovascular pressure reactivity should be the subject of future clinical trial in severe traumatic head-injury patients.

Pathogenesis of cerebral vasospasm following aneurysmal subarachnoid hemorrhage: Putative mechanisms and novel approaches

Cerebral vasospasm is a potentially incapacitating or lethal complication in patients with aneurysmal subarachnoid hemorrhage (SAH). The development of effective preventative and therapeutic interventions has been largely hindered by the fact that the underlying pathogenic mechanisms of cerebral vasospasm remain poorly understood. However, intensive research during the last 3 decades has identified certain mechanisms that possibly play a role in its development. Experimental data suggest that calcium‐dependent and ‐independent vasoconstriction is taking place during vasospasm. It appears that the breakdown products of blood in the subarachnoid space are involved, through direct and/or indirect pathways, in the development of vasospasm after SAH. Free radicals reactions, an imbalance between vasoconstrictor and vasodilator substances (endothelium derived substances, e.g., nitric oxide, endothelin; arachidonic acid metabolites, e.g., prostaglandins, prostacyclin), inflammatory processes, an upheaval of neuronal mechanisms that regulate vascular tone, endothelial proliferation, and apoptosis have all been put forward as causative and/or pathogenic factors. Translational research in the field of vasospasm has traditionally aimed to identify agents/interventions in order to block the cascades initiated after SAH. The combination of novel approaches such as cerebral microdialysis, magnetic resonance spectroscopy, proteomics, and lipidomics could serve a dual purpose: elucidating the complex pathobiochemistry of vasospasm and providing clinicians with tools for early detection of this feared complication. The purpose of this Mini‐Review is to provide an overview of the pathogenesis of cerebral vasospasm and of novel approaches used in basic and translational research.

Surgical research collaboratives in the UK

www.thelancet.com Vol 382 September 28, 2013 1091 Submissions should be made via our electronic submission system at http://ees.elsevier.com/ thelancet/ To our knowledge, these UK traineeled models are a world-first, and we welcome international collaboration to facilitate develop ment in other countries. A global surgical proof of principle study is planned for early 2014, with dissemination via social media (such as GlobalSurg). We hope that this will make possible development of traineeled collaboratives on a truly global scale.

Chronic subdural haematoma: modern management and emerging therapies

Chronic subdural haematoma (CSDH) is one of the most common neurological disorders, and is especially prevalent among elderly individuals. Surgical evacuation is the mainstay of management for symptomatic patients or haematomas exerting significant mass effect. Although burr hole craniostomy is the most widely practised technique worldwide, approximately 10–20% of surgically treated patients experience postoperative recurrence necessitating reoperation. Given the increasing incidence of CSDH in a growing elderly population, a need exists for refined techniques that combine a minimally invasive approach with clinical efficacy and cost-effectiveness. In addition, nonsurgical treatment modalities, such as steroids, are attracting considerable interest, as they have the potential to reduce postoperative recurrence or even replace the need for surgery in selected patients. This Review provides an overview of the contemporary management of CSDH and presents considerations regarding future approaches that could further optimize patient care and outcomes.

Decompressive craniectomy: past, present and future

Decompressive craniectomy (DC)—a surgical procedure that involves removal of part of the skull to accommodate brain swelling—has been used for many years in the management of patients with brain oedema and/or intracranial hypertension, but its place in contemporary practice remains controversial. Results from a recent trial showed that early (neuroprotective) DC was not superior to medical management in patients with diffuse traumatic brain injury. An ongoing trial is investigating the clinical and cost effectiveness of secondary DC as a last-tier therapy for post-traumatic refractory intracranial hypertension. With regard to ischaemic stroke (malignant middle cerebral artery infarction), a recent Cochrane review concluded that DC improves survival compared with medical management, but that a higher proportion of DC survivors experience moderately severe or severe disability. Although many patients have a good outcome, the issue of DC-related disability raises important ethical issues. As DC and subsequent cranioplasty are associated with a number of complications, indiscriminate use of this surgery is not appropriate. Here, we review the evidence and present considerations regarding surgical technique, ethics and cost-effectiveness of DC. Prospective clinical trials and cohort studies are essential to enable optimization of patient care and outcomes.

Traumatic brain injury in adults

Traumatic brain injury (TBI) remains a major public health problem. This review aims to present the principles upon which modern TBI management should be based. The early management phase aims to achieve haemodynamic stability, limit secondary insults (eg hypotension, hypoxia), obtain accurate neurological assessment and appropriately select patients for further investigation. Since 2003, the mainstay of risk stratification in the UK emergency departments has been a system of triage based on clinical assessment, which then dictates the need for a CT scan of the head. For patients with acute subdural or extradural haematomas, time from clinical deterioration to operation should be kept to a minimum, as it can affect their outcome. In addition, it is increasingly recognised that patients with severe and moderate TBI should be managed in neuroscience centres, regardless of the need for neurosurgical intervention. The monitoring and treatment of raised intracranial pressure is paramount for maintaining cerebral blood supply and oxygen delivery in patients with severe TBI. Decompressive craniectomy and therapeutic hypothermia are the subject of ongoing international multi-centre randomised trials. TBI is associated with a number of complications, some of which require specialist referral. Patients with post-concussion syndrome can be helped by supportive management in the context of a multi-disciplinary neurotrauma clinic and by patient support groups. Specialist neurorehabilitation after TBI is important for improving outcome.

Clinical applications of intracranial pressure monitoring in traumatic brain injury

BackgroundIntracranial pressure (ICP) monitoring has been for decades a cornerstone of traumatic brain injury (TBI) management. Nevertheless, in recent years, its usefulness has been questioned in several reports. A group of neurosurgeons and neurointensivists met to openly discuss, and provide consensus on, practical applications of ICP in severe adult TBI.MethodsA consensus conference was held in Milan on October 5, 2013, putting together neurosurgeons and intensivists with recognized expertise in treatment of TBI. Four topics have been selected and addressed in pro-con presentations: 1) ICP indications in diffuse brain injury, 2) cerebral contusions, 3) secondary decompressive craniectomy (DC), and 4) after evacuation of intracranial traumatic hematomas. The participants were asked to elaborate on the existing published evidence (without a systematic review) and their personal clinical experience. Based on the presentations and discussions of the conference, some drafts were circulated among the attendants. After remarks and further contributions were collected, a final document was approved by the participants.Summary and conclusionsThe group made the following recommendations: 1) in comatose TBI patients, in case of normal computed tomography (CT) scan, there is no indication for ICP monitoring; 2) ICP monitoring is indicated in comatose TBI patients with cerebral contusions in whom the interruption of sedation to check neurological status is dangerous and when the clinical examination is not completely reliable. The probe should be positioned on the side of the larger contusion; 3) ICP monitoring is generally recommended following a secondary DC in order to assess the effectiveness of DC in terms of ICP control and guide further therapy; 4) ICP monitoring after evacuation of an acute supratentorial intracranial hematoma should be considered for salvageable patients at increased risk of intracranial hypertension with particular perioperative features.

Intracranial pressure monitoring in severe traumatic brain injury

Should not be abandoned on the basis of recent evidence

Decompressive craniectomy following traumatic brain injury: developing the evidence base

Abstract In the context of traumatic brain injury (TBI), decompressive craniectomy (DC) is used as part of tiered therapeutic protocols for patients with intracranial hypertension (secondary or protocol-driven DC). In addition, the bone flap can be left out when evacuating a mass lesion, usually an acute subdural haematoma (ASDH), in the acute phase (primary DC). Even though, the principle of “opening the skull” in order to control brain oedema and raised intracranial pressure has been practised since the beginning of the 20th century, the last 20 years have been marked by efforts to develop the evidence base with the conduct of randomised trials. This article discusses the merits and challenges of this approach and provides an overview of randomised trials of DC following TBI. An update on the RESCUEicp study, a randomised trial of DC versus advanced medical management (including barbiturates) for severe and refractory post-traumatic intracranial hypertension is provided. In addition, the rationale for the RESCUE-ASDH study, the first randomised trial of primary DC versus craniotomy for adult head-injured patients with an ASDH, is presented.

Primary decompressive craniectomy for acute subdural haematomas: results of an international survey

Dear Sir, Approximately two-thirds of patients with traumatic brain injury (TBI) undergoing emergency cranial surgery have an acute subdural haematoma (ASDH) evacuated [2]. These haematomas are frequently associated with underlying cerebral parenchymal injury, which further exacerbates brain swelling [5]. Therefore, even though craniotomy and evacuation comprise the established primary treatment for ASDH, leaving the bone flap out (i.e. decompressive craniectomy) is an option either because the brain is swollen beyond the confines of the cranium or because the patient is thought to be at high risk for worsening brain swelling during the ensuing days. The European Brain Injury Consortium survey, which was conducted in 2001, demonstrated that a decompressive craniectomy (DC) was undertaken in approximately onequarter of operations performed for ASDH [2]. Since then, there has been a resurgence of interest in the use of DC after TBI. A randomised controlled trial of early/neuroprotective DC in patients with severe diffuse TBI (but no mass lesions) was published in 2011 (DECRA), while another randomised study assessing the role of DC as a last-tier therapy for refractory post-traumatic intracranial hypertension (RESCUEicp) has now recruited 85 % of the required sample size [3, 4]. Nevertheless, there is only class III evidence with retrospective studies investigating the role of DC as a primary procedure for ASDH [1]. With the objective of examining current practice patterns of DC after TBI, we undertook a survey of members of the European Association of Neurosurgical Societies (EANS), Neurocritical Care Society, NeuroCritical Care Network (NCCNet), full members of the Society of British Neurological Surgeons (SBNS) and members of the British Neurosurgical Trainees Association (BNTA) during October and November 2011. We used a secure online survey tool to disseminate the questionnaires. The questionnaire survey was approved by the Academic Committee of the SBNS (project no. NE0026). In this letter, we wish to discuss the results of our survey regarding the use of primary DC for ASDH. As part of the survey, we asked the following question: “When evacuating a traumatic ASDH, how often do you perform a primary DC (i.e. leave the bone flap out)”? This question was answered by 283 neurosurgeons (201 board-certified Consultants or equivalent; 82 trainees). There were 138 UK/Irish, 110 from other European countries, 13North American and 22 respondents from various other countries (see Appendix 1). We decided to group together the responses of neurosurgeons working in countries with national representation to the EANS in order to have two similar-sized groups (UK/Irish A. G. Kolias : L. M. Li : I. Timofeev : E. A. Corteen : T. Santarius : J. D. Pickard : P. J. Kirkpatrick : P. J. Hutchinson Division of Neurosurgery, Addenbrooke’s Hospital & University of Cambridge, Cambridge, UK