Robson Luis Amorim

Decompressive craniectomy: a meta-analysis of influences on intracranial pressure and cerebral perfusion pressure in the treatment of traumatic brain injury

OBJECT In recent years, the role of decompressive craniectomy for the treatment of traumatic brain injury (TBI) in patients with refractory intracranial hypertension has been the subject of several studies. The purpose of this review was to evaluate the contribution of decompressive craniectomy in reducing intracranial pressure (ICP) and increasing cerebral perfusion pressure (CPP) in these patients. METHODS Comprehensive literature searches were performed for articles related to the effects of decompressive craniectomy on ICP and CPP in patients with TBI. Inclusion criteria were as follows: 1) published manuscripts, 2) original articles of any study design except case reports, 3) patients with refractory elevated ICP due to traumatic brain swelling, 4) decompressive craniectomy as a type of intervention, and 5) availability of pre- and postoperative ICP and/or CPP data. Primary outcomes were ICP decrease and/or CPP increase for assessing the efficacy of decompressive craniectomy. The secondary outcome was the persistence of reduced ICP 24 and 48 hours after the operation. RESULTS Postoperative ICP values were significantly lower than preoperative values immediately after decompressive craniectomy (weighted mean difference [WMD] -17.59 mm Hg, 95% CI -23.45 to -11.73, p < 0.00001), 24 hours after (WMD -14.27 mm Hg, 95% CI -24.13 to -4.41, p < 0.00001), and 48 hours after (WMD -12.69 mm Hg, 95% CI -22.99 to -2.39, p < 0.0001). Postoperative CPP was significantly higher than preoperative values (WMD 7.37 mm Hg, 95% CI 2.32 to 12.42, p < 0.0001). CONCLUSIONS Decompressive craniectomy can effectively decrease ICP and increase CPP in patients with TBI and refractory elevated ICP. Further studies are necessary to define the group of patients that can benefit most from this procedure.

Aplication of the stereolithography technique in complex spine surgery

Many techniques have been proposed for surgical training as a learning process for young surgeons or for the simulation of complex procedures. Stereolithograpfy, a rapid prototyping technique, has been presented recently as an option for these purposes. We describe the case of a 12 years old boy, diagnosed with Ewings sarcoma in the cervical spine. After a surgical simulation accomplished in the prototype, built by stereolithography, the patient was submitted to a C4 corpectomy and to a C4 and C3 laminectomy with anterior and posterior fixation, a non intercurrence procedure. This technique is an innovative and complementary tool in diagnosis and therapy. As a result, it is easier for the surgeon to understand the complexity of the case and plan the approach before any surgical procedure.

Mecanismos de lesão cerebral no traumatismo cranioencefálico

Traumatic brain injury is the main cause of death and disability in children and adults in Western Countries. The definitive brain injury is a consequence of pathophysiological mechanisms that begin at the moment of an accident and may extend for days or weeks. Traumatic brain injury may be classified as diffuse or focal. These two mechanisms are commonly associated in a patient, however one is generally predominant. Therefore knowledge of the pathophysiological mechanisms of brain injury in head trauma is important to establish the therapeutic, clinical and surgical measures. In this paper the authors present a critical review of the literature on the pathophysiological principles of traumatic brain injury.

The Puzzling Olfactory Groove Schwannoma: A Systematic Review

We systematically reviewed the literature concerning the anterior cranial fossa schwannomas to understand their pathogenesis, determine their origin, and standardize the terminology. We performed a MEDLINE, EMBASE, and Science Citation Index Expanded search of the literature; age, gender, clinical presentation, presence or absence of hyposmia, radiological features, and apparent origin were analyzed and tabulated. Cases in a context of neurofibromatosis and nasal schwannomas with intracranial extension were not included. Age varied between 14 and 63 years (mean = 30.9). There were 22 male and 11 female patients. The clinical presentation included seizures (n = 15), headache (n = 16), visual deficits (n = 7), cognitive disturbances (n = 3), and rhinorrhea (n = 1). Hyposmia was present in 14 cases, absent in 13 cases (39.3%), and unreported in five. Homogeneous and heterogeneous contrast enhancement was observed in 14 and 15 cases, respectively. The region of the olfactory groove was the probable site in 96.5%. Olfactory tract could be identified in 39.3%. The most probable origin is the meningeal branches of trigeminal nerve or anterior ethmoidal nerves. Thus, olfactory groove schwannoma would better describe its origin and pathogenesis and should be the term preferentially used to name it.

Effects of hyperbaric oxygenation therapy on symptomatic pneumocephalus

Background Pneumocephalus (PNC) is defined as a pathological collection of gas within the cranial cavity. The authors studied the effects of hyperbaric oxygenation (HBO2) therapy on a group of patients with PNC, comparing them with a control group to determine the relative impact on pneumocephalus volume, clinical symptoms, and duration of hospitalization. Methods Twenty-four patients with PNC treated at our hospital were consecutively studied. These patients were divided into a treated group (n=13) and a control group (n=11). Thirteen patients (treated group) were treated with HBO2 therapy sessions in a monoplace hyperbaric chamber at 2.5 atmospheres with 100% oxygen concentration. The control group was treated with normobaric oxygenation. Results Clinical improvement was seen in all patients. In the treated group, a decrease of the gas bubble was observed on the computerized tomography scan after each session of HBO2. The treated group also experienced a lower rate of meningitis compared with the control group. The length of hospital stay was significantly higher in the control group compared with the treated group. Conclusions HBO2 therapy in selective cases may lead to clinical and radiological improvement in patients with PNC.

Comprehensive cognitive and cerebral hemodynamic evaluation after cranioplasty

Decompressive craniectomy is an established procedure to lower intracranial pressure and can save patients’ lives. However, this procedure is associated with delayed cognitive decline and cerebral hemodynamics complications. Studies show the benefits of cranioplasty beyond cosmetic aspects, including brain protection, and functional and cerebrovascular aspects, but a detailed description of the concrete changes following this procedure are lacking. In this paper, the authors report a patient with trephine syndrome who underwent cranioplasty; comprehensive cognitive and cerebral hemodynamic evaluations were performed prior to and following the cranioplasty. The discussion was based on a critical literature review.

Improved Hemodynamic Parameters in Middle Cerebral Artery Infarction After Decompressive Craniectomy

Background and Purpose— Decompressive craniectomy (DC) reduces mortality and improves functional outcome in patients with malignant middle cerebral artery infarction. However, little is known regarding the impact of DC on cerebral hemodynamics. Therefore, our goal was to study the hemodynamic changes that may occur in patients with malignant middle cerebral artery infarction after DC and to assess their relationship with outcomes. Methods— Twenty-seven patients with malignant middle cerebral artery infarction who were treated with DC were studied. The perfusion CT hemodynamic parameters, mean transit time, cerebral blood flow, and cerebral blood volume were evaluated preoperatively and within the first 24 hours after DC. Results— There was a global trend toward improved cerebral hemodynamics after DC. Preoperative and postoperative absolute mean transit times were associated with mortality at 6 months, and the ratio of post- and preoperative cerebral blood flow was significantly higher in patients with favorable outcomes than those with unfavorable outcomes. Patients who underwent surgery 48 hours after stroke, those with midline brain shift >10 mm, and those who were >55 years showed no significant improvement in any perfusion CT parameters. Conclusions— DC improves cerebral hemodynamics in patients with malignant middle cerebral artery infarction, and the level of improvement is related to outcome. However, some patients did not seem to experience any additional hemodynamic benefit, suggesting that perfusion CT may play a role as a prognostic tool in patients undergoing DC after ischemic stroke.

Surgical treatment of a transorbital penetrating brain injury.

Penetrating injury of the skull and brain are relatively uncommon events, representing about 0.4% of all head injuries. Transorbital penetrating brain injury is an unusual occurrence in emergency practice and presents with controversial management. We report the case of a 10-year-old boy who fell forward on a bamboo stick while playing with other children, causing a penetrating transorbital injury, resulting in meningitis. We performed a combined surgical approach with neurosurgeons and ophthalmogic surgeons. Upon discharge, the patient had a Glasgow Coma Scale score of 15, no motor deficit and no visual loss. We discuss the management of this case and review current literature.

3D Preoperative Planning in the ER with OsiriX®: When There is No Time for Neuronavigation

The evaluation of patients in the emergency room department (ER) through more accurate imaging methods such as computed tomography (CT) has revolutionized their assistance in the early 80s. However, despite technical improvements seen during the last decade, surgical planning in the ER has not followed the development of image acquisition methods. The authors present their experience with DICOM image processing as a navigation method in the ER. The authors present 18 patients treated in the Emergency Department of the Hospital das Clínicas of the University of Sao Paulo. All patients were submitted to volumetric CT. We present patients with epidural hematomas, acute/subacute subdural hematomas and contusional hematomas. Using a specific program to analyze images in DICOM format (OsiriX®), the authors performed the appropriate surgical planning. The use of 3D surgical planning made it possible to perform procedures more accurately and less invasively, enabling better postoperative outcomes. All sorts of neurosurgical emergency pathologies can be treated appropriately with no waste of time. The three-dimensional processing of images in the preoperative evaluation is easy and possible even within the emergency care. It should be used as a tool to reduce the surgical trauma and it may dispense methods of navigation in many cases.

A rare case of olfactory groove schwannoma

Supervisor and Cerebrovascular Surgical Coordinator, Division of Neurological Surgery, University of Sao Paulo, School of Medicine, Sao Paulo SP, Brazil; Skull Base Surgical Coordinator, Division of Neurological Surgery, University of Sao Paulo, School of Medicine, Sao Paulo SP, Brazil; Assistant Professor, Department of Neurosurgery, Brain Research Institute, Nigata University, Nigata, Japan; Resident, Division of Neurological Surgery, University of Sao Paulo, School of Medicine, Sao Paulo SP, Brazil; Chairman, Department of Pathology, University of Sao Paulo, School of Medicine, Sao Paulo SP, Brazil; Chairman, Division of Neurological Surgery, University of Sao Paulo, School of Medicine, Sao Paulo SP, Brazil.