Ran Harel

Sheba Medical Center | sheba · neurosurgery

Minimization of the surgical approaches to spinal extradural metastases resection and stabilization was advocated by the 2012 Oncological Guidelines for Spinal Metastases Management. Minimally invasive approaches to spine oncology surgery (MISS) are continually advancing. This paper will describe the evolution of minimally invasive surgical techniq...

Objective: To ameliorate the clinical decision-making process when debating between a ventral or dorsal cervical approach by elucidating whether post-operative dysphagia be regarded as a complication or a transient side effect. Methods: A literature review of studies comparing complication rates following ventral and dorsal cervical approaches w...

Introduction: Degenerative cervical myelopathy (DCM) is a common condition often treated by surgical decompression and fusion. The objective of this paper was to compare short-term post-operative complication rates of patients with multi-level DCM treated with decompression and fusion using either an anterior or a posterior cervical approach. Mat...

Purpose This pilot study was undertaken to evaluate the safety, performance, and usability of the Xvision Spine (XVS) System during open spinal fixation procedures in patients requiring pedicle screw placement in the lumbosacral spine. Methods The XVS System is an augmented reality head-mounted display (HMD) based upon a computer navigation system...

Background To advocate the formulation of a new index termed MRI Blind Zone, designated to predict the dimensions of the magnetic resonance metallic artifact caused by specific spinal implants. The index may also specify the obscured organs of interest. Methods A retrospective evaluation of post-operative MR images of patients operated for spinal...

Objective: Ventral thoracic meningiomas may pose a technical challenge owing to a limited surgical corridor and the presence of longstanding ventral cord compression. Unopposed dorsal spinal cord migration may occur following a bilateral laminectomy resulting in immediate neurological injury. We discuss the possible mechanism underlying such a phe...

Purpose The upper cervical spine region is densely populated by neural and vascular structures impeding the approach for fusion surgery. Technological advancement simplify the approach to C1-C2 fusion, thus reduce risks. The current paper purpose is to describe initial experience with a novel technique modification for C1 lateral screw insertion th...

Titanium dioxide (TiO2) is a frequently used biomaterial, particularly in orthopedic and dental implants, and it is considered an inert and benign compound. This has resulted in toxicological scrutiny for TiO2 in the past decade, with numerus studies showing potential pathologic downstream effects. Herein we describe case report of a 77-year-old ma...

Background A definitive diagnosis of brain lesions not amenable to surgery is mainly made by stereotactic needle biopsy. The diagnostic yield and safety of the frameless vs frame-based image-guided stereotactic techniques is unclear. Objective To evaluate the safety and accuracy of frameless vs frame-based stereotactic brain biopsy techniques. Me...

Objective: The use of intraoperative neuromonitoring (IONM) has become an imperative adjunct to the resection of intramedullary spinal cord tumors (IMSCTs). While the diagnostic utility of IONM during the immediate postoperative period has been previously studied, its long-term diagnostic accuracy has seldom been thoroughly assessed. The aim of th...

Objective: To determine the utility of an intraoperative magnetic resonance imaging (iMRI) system, the Polestar N30, for enhancing the resection control of non-enhancing intra-axial brain lesions. Material and methods: Seventy-three patients (60 males [83.3%], mean age 37 years) with intra-axial brain lesions underwent resection at Sheba Medical...

Significance Thalamocortical interactions are a key component of normal brain functions both in sensory and motor areas. The fact that TC connectivity is excitatory has led to the suggestion that its main role is positively driving motor cortical activity. Here we show that the motor thalamus has contrasting, area-dependent interactions with cortic...

Objective Spinal Dural Arteriovenous Fistulas (SDAVF) are rare vascular malformations. Digital subtraction angiography (DSA) is the modality of choice to demonstrate the malformation prior to endovascular embolization or open surgical repair. Angiographically occult SDAVF have been previously reported. Surgical considerations in SDAVF with misleadi...

Objective: To describe a novel technique modification and evaluate initial results of pedicle screw insertion in minimally invasive transforaminal lumbar interbody fusion (MITLIF), using self-drilling self-tapping one-step screws. Patients and Methods: All patients who were operated for MITLIF using the one-step technique over the last 6 months per...

Objective: Atlanto-occipital dislocation is usually considered to be a fatal injury or one that leaves the victim with serious neurological deficits. The aim of this study is to illustrate a novel positive prognostic factor for atlanto-occipital dislocation, based on cervical MRI studies of patients who suffered this injury. Methods: Over the cours...

Cortical maps often undergo plastic changes during learning or in response to injury. In sensory areas, these changes are thought to be triggered by alterations in the pattern of converging inputs and a functional reassignment of the deprived cortical region. In the motor cortex, training on a task that engages distal effectors was shown to increas...

Aims and objectives: To review a series of patients with brain metastases from ovarian cancer at a single institution. To describe treatment modalities, their outcomes and to determine prognostic factors. Patients and methods: Between January 1995 and December 2014, 25 patients with ovarian cancer brain metastases were treated at The Sheba Medic...

Study Design Retrospective cohort study. Objectives The learning curve associated with the implementation of minimally invasive spinal surgery (MIS) has been the center of attention in numerous publications. So far, these studies referred to a single MIS procedure. In our view, minimally invasive surgical skills are acquired simultaneously through...

Background Cervical axial spine fusion is challenging as the anatomy is extremely variable, and screw misplacement can lead to severe complications. C1 lateral mass screws and C2 pedicle screws are routinely placed under either fluoroscopic guidance or imaging-assisted navigation. Here, we compared the two for axial screw placement. Methods We ret...

Coordinated movements are achieved by well-timed activation of selected muscles. This process relies on intact cerebellar circuitry, as demonstrated by motor impairments following cerebellar lesions. Based on anatomical connectivity and symptoms observed in cerebellar patients, we hypothesized that cerebellar dysfunction should disrupt the temporal...

OBJECTIVE Augmented reality (AR) is a novel technology that has the potential to increase the technical feasibility, accuracy, and safety of conventional manual and robotic computer-navigated pedicle insertion methods. Visual data are directly projected to the operator’s retina and overlaid onto the surgical field, thereby removing the requirement...

Coordinated movements are achieved by selecting muscles and activating them at specific times. This process relies on intact cerebellar circuitry, as demonstrated by motor impairments triggered by cerebellar lesions. Based on anatomical connectivity and symptoms observed in cerebellar patients, we hypothesized that cerebellar dysfunction should dis...

Purpose: Application of the anterior sub-axial cervical approach to the axial spine or the high thoracic spine has been previously described. Evaluation methods to determine the feasibility of these approaches were also described but alternative method was utilized in the current study. We describe our experience expanding the boundaries of anterio...

In higher mammals, motor timing is considered to be dictated by cerebellar control of motor cortical activity, relayed through the cerebellar-thalamo-cortical (CTC) system. Nonetheless, the way cerebellar information is integrated with motor cortical commands and affects their temporal properties remains unclear. To address this issue, we activated...

Nerve sheath tumors and meningiomas account for most intradural extramedullary (IDEM) tumors. These tumors are benign and amenable to complete surgical resection. In recent years, these surgeries are performed with intraoperative neurophysiologic monitoring (IONM) in order to minimize neurological injury, but the evidence for the statistical effica...

Cerebellar control of voluntary movements is achieved by the integration of external and internal feedback information to properly adjust and correct ongoing actions. In the forelimb of primates, rostral-spinocerebellar tract (RSCT) neurons are thought to integrate segmental, descending and afferent sources and relay upstream a compound signal that...

OBJECTIVE Local therapy to spine tumors has been shown to be effective in selected cases. Spinal radiosurgery (SRS) is an evolving radiotherapy regimen allowing for noninvasive, highly efficacious local treatment. The learning curve can compromise the results of any newly employed technology and should be studied to minimize its effects. In this pa...

Objective Nontraumatic acute cervical disk herniation resulting in acute severe neurologic deficit is a rare entity described in a limited number of case reports. We describe the management and outcome in patients presenting with severe neurologic deterioration caused by acutely herniated cervical disks. Methods Four patients (mean age 39.5 years)...

Objective: Cervical spine surgery is a common procedure for treatment of wide variety of pathologies. In this paper we report approach-related complication rates experienced by our patients. Methods: We retrospectively evaluated patients' data treated surgically for cervical pathologies from February 2011 to October 2013. Medical records were co...

Background: Spine surgery relies heavily on imaging, with radiography-based devices being the major operating room imaging modality. Radiation exposure is an occupational risk historically recognized shortly after the discovery of radiation itself. Exposure of both patients and operating room staff is of increasing concern as the knowledge regardi...

Purpose: Spine stereotactic radiosurgery (SRS) delivers an accurate and efficient high radiation dose to vertebral metastases in 1-5 fractions. We aimed to compare volumetric modulated arc therapy (VMAT) to static beam intensity modulated radiotherapy (IMRT) for spine SRS. Methods and materials: Ten spine lesions of previously treated SRS patien...

Objective: The present study evaluated the optimal measuring criteria to assess spinal tumor response to surgery followed by Stereotactic Spine Radiosurgery (SRS) and reports the local control and wound complication rates following combined multimodality treatment. Methods and materials: Prospectively collected patient information was retrospect...

Intraoperative ultrasound (IUS) has been described in numerous papers as an effective tool for spinal tumor resection, degenerative lesions and Chiari malformation surgery, but has not been routinely adopted by spine surgeons. We herein describe our experience with routine IUS application. In 2011, the authors began to use Aloka Prosound Alpha 7 at...

Spinal metastases compressing the spinal cord are a medical emergency and should be operated on if possible; however, patients’ medical condition is often poor and surgical complications are common. Minimizing surgical extant, operative time, and blood loss can potentially reduce postoperative complications. This is a retrospective study describing...

Early diagnosis, better imaging, and advanced treatment of cancer patients extend survival and increase the incidence of symptomatic spine metastases. The treatment algorithm for spine metastases has shifted to a more aggressive approach in recent years. Spine stereotactic radiosurgery (SRS) is a relatively new tool utilizing advanced imaging syste...

Transmission of information in the corticospinal (CS) route constitutes the fundamental infrastructure for voluntary actions. The anatomy of this pathway has been studied extensively, but there is little direct evidence regarding its functional organization. Here we explored the areal specificity of CS connections by studying two related questions:...

Study design: Retrospective review. Objective: The objective of the study was to determine the morbidity and mortality rate associated with same day versus staged cervical circumferential approach. Summary of background data: A combined approach to the cervical spine is often indicated for complex cervical pathologies. Previous studies suggest...

Oncomodulin, an ~12 kDa Ca(2+)-binding protein secreted from activated macrophages, has been shown to promote axonal regeneration from retinal ganglion cells (RGCs) following optic nerve injury. However, to date, the axonal growth-promoting capacity of oncomodulin in other models of 'regenerative failure' has not been evaluated. We assessed the cap...

Cervical kyphosis may develop in patients with a variety of conditions. It commonly occurs following cervical spine surgery. To our knowledge, no specific physical examination finding in patients with cervical kyphosis has been previously described. It has been our observation that patients with symptomatic cervical kyphosis often have prominent, t...

Spinal neurons operate as a processing link that integrates descending and peripheral information and in turn, generates a specific yet complex muscle command. The functional organization of spinal circuitry during normal motor behavior dictates the way in which this translation process is achieved. Nonetheless, little is known about this organizat...

Spinal metastases are the most frequently encountered spinal tumour and can affect up to 50% of cancer patients. Both the incidence and prevalence of metastases are thought to be rising due to better detection and treatment options of the systemic malignancy resulting in increased patient survival. Further, the development and access to newer imagi...

To evaluate whether stereotactic spine radiosurgery (SRS) results in lower rates of instrumentation failure or higher rates of fusion compared with surgical decompression and stabilization combined with conventional fractionated radiation (XRT) in patients with spine tumors. The Cleveland Clinic Spine Tumor board database was retrospectively review...

Performing voluntary motor actions requires the translation of motor commands into a specific set of muscle activation. While it is assumed that this process is carried out via cooperative interactions between supraspinal and spinal neurons, the unique contribution of each of these areas to the process is still unknown. Many studies have focused on...

It was suggested previously that the transformation of action to muscle-based coding is completed in the primary motor cortex (M1). This is consistent with a predominant direct pathway leading from M1 to motoneurons. Accordingly, spinal segmental interneurons that are located downstream to M1 are expected to show muscle-like coding properties. We a...

Corticospinal (CS) pathways provide the structural foundation for executing voluntary movements. Although the anatomy of these pathways is well explored, little is known about spinal decoding of parametric information transmitted via this route during voluntary movements. We addressed this question by simultaneously recording cortical and spinal ac...

The objective of this prospective 18-month study was to evaluate the clinical and laboratory effects of repeated intrathecal injections of chemotherapy in children with acute leukemia. All procedures were performed under general anesthesia, and complications were prospectively recorded. Laboratory measurements included lumbar puncture opening press...

To retrospectively delineate predictors of adverse outcome by looking at the demographic features, therapy and outcome of systemic candida infection in a large tertiary care university-affiliated medical center. We reviewed the clinical data on 186 inpatients with candidemia over a 6-year period. The major reason for their hospital admission was an...

Invasive group A streptococcal (GAS) infections are increasing alarmingly worldwide. To determine the clinical and epidemiologic characteristics of invasive GAS in a large tertiary medical center, we retrospectively surveyed microbiology and medical records of patients with invasive GAS infections (isolation of Group A Streptococcus from a normally...

The aim of the study was to evaluate long-term pulmonary function tests in pediatric survivors of acute respiratory distress syndrome (ARDS). Observational study based on a telephone poll of retrospectively identified post ARDS children who were hospitalized in a pediatric intensive care unit (PICU) in a general 1200-bed teaching, tertiary, regiona...

Interleukin (IL)-8, an 8 kDa peptide, is the first chemoattractant identified as being specific for neutrophils. Its possible association with early postoperative morbidity following cardiopulmonary bypass (CPB) in infants and children is unknown. This prospective cohort study sought possible roles of IL-8 in the inflammatory response to CPB and in...

The purpose of this study was to delineate early respiratory predictors of mortality in children with hemato-oncology malignancy who developed acute respiratory distress syndrome (ARDS). Materials and Methods: We conducted a retrospective chart review of children with malignant and ARDS who needed mechanical ventilation and were admitted to a pedia...

Surgery involving cardiopulmonary bypass (CPB) is frequently accompanied by a systemic inflammatory response partly triggered by neutrophils and monocyte-macrophages. Certain cytokines that are powerful leukocyte-chemotactic factors have recently been characterized and shown to be important in evoking inflammatory responses: monocyte chemoattractan...

Acute epidural hematoma (AEH), a relatively common complication of head injury in children, persists in bearing high morbidity and mortality. Early establishment of prognosis could guide optimal patient allocation, and early identification of predictive signs could assist in choosing appropriate therapeutic interventions. This study aimed to deline...

Purpose: The clinical literature on the incidence and subsequent mortality of adult respiratory distress syndrome (ARDS) has come primarily from the experiences of large tertiary referral centers, particularly in Western Europe and North America. Consequently, very little has been published on the incidence, management, and outcome of ARDS in smal...

An unselected series of 200 consecutive cases of major head trauma in children aged 6 months to 16 years, seen during 4 years, was studied. Injuries were due to road accidents (40%), falls (30.5%) and other causes (29.5%), and were assessed clinically and by cranial CT. On admission the Glasgow Coma Score ranged from 4.72-11.65 and in addition to p...

Falls are the foremost reason for non-fatal injuries and are second only to motor vehicle accidents in causing accidental death. The purpose of this study was to identify the clinical and metabolic predictors of the outcome of head injury caused by falls from a height. Medical records of 61 children who had been admitted to the paediatric intensive...