Matteo M. Bonsanto

Clinical evaluation and follow-up results for intraoperative magnetic resonance imaging in neurosurgery.

OBJECTIVE The use of intraoperative magnetic resonance imaging (MRI) in neurosurgery has increased rapidly, and a variety of concepts have recently been presented. Although the feasibility of the procedure has been demonstrated repeatedly, no conclusive analysis of its effects on the surgical procedures, the extent of tumor removal, and outcomes, or its possible problems, has been performed. METHODS Of 242 operations performed with intraoperative MRI, 97 procedures for supratentorial glioma treatment were analyzed with respect to intraoperative imaging results and postoperative outcomes. Analysis of the images included assessment of imaging artifacts, image quality, and extent of tumor removal. Patients were monitored to determine radiological progression, survival times, postoperative complications, and morbidity rates. RESULTS No intraoperative complications related to the imaging procedure were observed. Image quality was good or fair in 85.5% of the cases. Different types of surgically induced imaging changes could be identified. In 56 cases, resection was continued using navigation with intraoperative MRI data sets (rereferencing accuracy, 0.9 mm). For high-grade gliomas, the percentage of cases in which residual tumor was identified by MRI could be significantly reduced from 62% intraoperatively to 33% postoperatively, which was paralleled by a significant increase in survival times for patients without residual tumor. Complication and morbidity rates were within the ranges reported for other studies. CONCLUSION Intraoperative MRI is safe and allows reliable updating of neuronavigational data, with compensation for brain shifting. Surgically induced imaging changes, which have been identified as a possible problem with intraoperative MRI in general, necessitated comparisons with preoperative scans and require future attention. The extent of tumor removal and survival times were increased significantly. Overall, patients seemed to benefit from the method.

Antitumor Vaccination of Patients With Glioblastoma Multiforme: A Pilot Study to Assess Feasibility, Safety, and Clinical Benefit

PURPOSE Prognosis of patients with glioblastoma is poor. Therefore, in glioblastoma patients, we analyzed whether antitumor vaccination with a virus-modified autologous tumor cell vaccine is feasible and safe. Also, we determined the influence on progression-free survival and overall survival and on vaccination-induced antitumor reactivity. PATIENTS AND METHODS In a nonrandomized study, 23 patients were vaccinated and compared with nonvaccinated controls (n = 87). Vaccine was prepared from patients tumor cell cultures by infection of the cells with Newcastle Disease Virus, followed by gamma-irradiation, and applied up to eight times. Antitumor immune reactivity was determined in skin, blood, and relapsed tumor by delayed-type hypersensitivity skin reaction, ELISPOT assay, and immunohistochemistry, respectively. RESULTS Establishment of tumor cell cultures was successful in approximately 90% of patients. After vaccination, we observed no severe side effects. The median progression-free survival of vaccinated patients was 40 weeks (v 26 weeks in controls; log-rank test, P = .024), and the median overall survival of vaccinated patients was 100 weeks (v 49 weeks in controls; log-rank test, P < .001). Forty-five percent of the controls survived 1 year, 11% survived 2 years, and there were no long-term survivors (> or = 3 years). Ninety-one percent of vaccinated patients survived 1 year, 39% survived 2 years, and 4% were long-term survivors. In the vaccinated group, immune monitoring revealed significant increases of delayed-type hypersensitivity reactivity, numbers of tumor-reactive memory T cells, and numbers of CD8(+) tumor-infiltrating T-lymphocytes in secondary tumors. CONCLUSION Postoperative vaccination with virus-modified autologous tumor cells seems to be feasible and safe and to improve the prognosis of patients with glioblastomas. This could be substantiated by the observed antitumor immune response.

Initial experience with an ultrasound-integrated single-RACK neuronavigation system.

Summary A prototype ultrasound-integrated neuronavigation system was tested in 34 operations as regards image quality, stability, and handling during daily use in the operating theatre. The system consists of a high-end ultrasound scanner, a navigation computer, and an active optical positioning and digitiser system, all integrated in a single rack. An Ethernet interface between the two hardware devices enables digital data transfer between the ultrasound scanner and the navigation device without loss of image quality. The integration of an ultrasound scanner and a navigation device offers the opportunity of navigating directly to an intracranial or intraspinal lesion using intra-operative 3D ultrasound images. The brainshift problem is thus avoided. The ability to directly compare MR images and 3D ultrasound simplifies the interpretation of ultrasound images. The single-rack solution is an advantage in times of restricted space in the operating theatre caused by the increasing volume of technical equipment needed for a neurosurgical operation. In 30 cases the prototype system showed good reliability. In four cases the navigation system failed during the operation; however, the capacity of the ultrasound scanner was still available as a stand-alone function. With the single-rack concept, the flexibility of the system is high and the complete device can easily be moved from one operating theatre to another.

Neuronavigation Methoden und Ausblick

ZusammenfassungMit den Fortschritten in der Computertechnologie und der neuroradiologischen Bildgebung wurde die Entwicklung der Neuronavigation möglich. Diese wird seither immer häufiger angewendet und hat die rahmenbasierte Stereotaxie zur intraoperativen Führung bei mikrochirurgischen, intrakraniellen Operationen weitgehend abgelöst. Mit Hilfe von dreidimensionalen Digitalisierinstrumenten werden dabei die präoperativ angefertigten CT- oder MRT- Bilder eines Patienten währen der Operation auf den Operationssitus übertragen. So wird eine genaue Lokalisation von Läsionen wie Tumoren oder anatomischen Strukturen ermöglicht. Die verwendeten Techniken wie positionsfühlende Gelenkarme, Infrarot- oder Robotersysteme werden ebenso wie die Anwendung in der klinischen Routine dargestellt. In 200 Eingriffen, die mit Neuronavigation durchgeführt wurden, hat sich die Methode als sehr hilfreich zur minimal invasiven Eingriffsplanung und -durchführung erwiesen. Mit Abweichungen zwischen 2 und 4 mm ist die Genauigkeit nur geringfügig schlechter als die Werte, wie sie für die rahmenbasierte Stereotaxie angegeben werden. Als besonders vorteilhaft wurde die Navigation von den Operateuren bei Eingriffen an der Schädelbasis sowie kleinen, tiefliegenden oder in eloquenten Arealen gelegenen Läsionen eingestuft. Hauptnachteil der Methode ist die Verwendung von präoperativem Bildmaterial, was zu Ungenauigkeiten führt, wenn es im Verlauf einer Operation durch zunehmende Tumorresektion zu Veränderungen der Anatomie kommt. Hier könnten Verfahren der intraoperativen Bildgebung wie der MRT eine Lösung darstellen. So ist es uns bereits gelungen, durch Aktualisierung der Navigationsdaten mit intraoperativer MRT Verschiebungen auszugleichen. Diese Entwicklungen werden zu einer zunehmenden Bedeutung der Neuronavigation in der operativen Routine führen, was durch eine Senkung der Operationsmorbidität auch erhebliche Auswirkungen auf die Indikationsstellung zu neurochirurgischen Eingriffen haben wird.SummaryWith the recent developments in computer technology and the improvements in modern neuroimaging, frame-based stereotactic guidance for open microsurgical procedures has been increasingly replaced by neuronavigation, also called frameless stereotaxy. It allows transfer of individual patientís images onto the operative field to assist the neurosurgeon intraoperatively in defining the tumor margins or identifying functionally important brain areas. The different localization techniques employed are articulated position-sensing arms, infrared or ultrasound systems working with the principle of satellite navigation and robotic systems integrated with the operating microscope. In 200 operations performed with different systems (arm-based, robotic and infrared) the method proved to be helpful, enabling fewer invasive procedures to be performed. With a mean deviation of 2.87±1.9 mm for intraoperative localization, the accuracy was only slightly worse than in frame-based stereotaxy with deviations below 2 mm. Neuronavigation was most helpful for operations on deeply seated lesions, skull-base tumors and lesions in brain areas with high functionality. The major disadvantage is the use of preoperative data for navigation, leading to inaccuracies when anatomical structures are altered during the operation by resection of tumors or shift of intracranial soft tissue. Intraoperative magnetic resonance imaging (MRI) might be a solution for this problem. With the method of intraoperative MRI developed in our department it has already been possible to update neuronavigation with images reflecting intraoperative changes in anatomy. Therefore, neuronavigation is definitely a method with growing importance in operative routine, and it will also spread into other surgical specialties.

3D ultrasound navigation in syrinx surgery – a feasibility study

SummaryBackground. The prototype of a 3D ultrasound navigation system, with a trackable 4- to 8-MHz phased-array ultrasound probe was used in syrinx-surgery. The aim of this study was to evaluate the advantages offered by 3D ultrasound and navigation in syringomyelial surgery.Methods and materials. After laminectomy, with a free-handed tilt of the ultrasound probe, the 3D volume of the target area is acquired within 15 seconds. The data are visualized after reconstruction in an axial, coronal, and sagittal view, offering the possibility of ultrasound-based guided surgery.Results. Based on the intraoperative volume information, it was possible to navigate with the 3D ultrasound images in all cases. The orientation and image quality with respect to resolution, spatial information, and the identification of anatomical structures facilitated the surgery in all seven cases.The navigation tool, with a length of 12 cm and a tip diameter of 1 mm, was simple to place into the surgical site. The availability of an up-to-date 3D-image resulted in less interruption of the surgical procedure, with no need to repeatedly fill the cavity with sterile saline for new ultrasound acquisitions. New ultrasound images were only required if shift occurred.The coronal and “trajectory-plane” views, offer additional information about the syrinx cavity. The target borders are easier to determine and orientation in separated cavities was possible. Particularly in syringomyelial surgery it was helpful to determine the surface point of the syrinx to place the myelotomy or insert a catheter.Conclusion. 3D ultrasound offers the advantages of visualizing the third dimension of the target. For orientation and border determination navigation within the 3D ultrasound volume is very helpful and can take place with the ultrasound probe out of the way. Any disruption in the surgical procedure is minimized by not having to repeatedly fill the cavity with a sterile saline solution, there are fewer difficulties with image orientation because of new image adjustments.

A Complication Conference for Internal Quality Control at the Neurosurgical Department of the University of Heidelberg

The registration of adverse events is an important issue in the field of medicine. Even today adverse event screening and registration is not part of the routine in most medical areas. In 1994, the Department of Neurosurgery at the University of Heidelberg implemented a conference for screening and registering adverse events. The aim was to record all complications occurring for an internal quality control. High priority was given to improving the process of data screening and registering. The conference is held every 2 weeks and all medical staff and residents of the department are obligated to be present. Screening of the adverse events encompasses all operations performed during a bi-weekly period. Every single operation is revised for an adverse event during or following the hospital stay. Adverse events are registered on a standardized data sheet and later transferred to a database for use in further investigations. After 6 years, the conference has been fully accepted and become an integral part of the workflow of the department. During this period, 8160 operations were screened and 1335 adverse events registered. The next step will be to integrate the data-collection process into the daily ward rounds using a personal digital assistant (PDA). This process is less time consuming and may perhaps augment the number of registered cases.

Clinical Impact of Intraoperative Magnetic Resonance Imaging on Central Nervous System Neoplasia

Abstract:Despite the introduction of neuronavigation, radicality is still an issue in operations for central nervous system neoplasia leading to integration of intraoperative magnetic resonance imaging (iMRI). The aim of the current study was to evaluate its clinical impact with regard to its potent

Virtuelle Realität in der Neurochirurgie

ZusammenfassungDefinition: Virtuelle Realität (VR) erlaubt dem Benutzer, in eine dreidimensionale Welt einzutauchen (engl.: to immerse, daher immersive VR) und in dieser virtuellen Welt zu agieren. Damit unterscheidet sich die VR von den bekannten Vorstellungen, z.B. in Computerspielen, wo man aktiv in einer irrealen Welt agiert, oder in Spielfilmen, wo man passiv an einer realen Welt teilnimmt. In der virtuellen Realität agiert man aktiv in einer Welt mit realistisch erscheinenden Elementen, die ihr Erscheinungsbild ändern können und daher „weitgehend unberechenbar” sind. Anwendung: Virtuelle Realität hat den Einzug nicht nur in Spielhallen und die Unterhaltungsindustrie gefunden, sondern auch in industrielle Fertigungsanlagen (Autos, Möbel usw.), militärische Bereiche und die Medizin. Gerade die beiden letzten Bereiche sind eng verknüpft, denn mit dem Begriff Telemedizin verband sich ursprünglich die Idee, im Kriegsfall Operationen an verwundeten Soldaten mit ferngesteuerten Robotern aus sicherem Abstand heraus durchzuführen oder Astronauten von der Erde aus zu behandeln. In der Medizin, speziell in der Neurochirurgie, werden heute bereits virtuelle Methoden zu Ausbildungszwecken, zur Operationsplanung und zu Operationen am virtuellen Patienten eingesetzt.SummaryDefinition: Virtual reality enables users to immerse themselves in a virtual three-dimensional world and to interact in this world. The simulation is different from the kind in computer games, in which the viewer is active but acts in a nonrealistic world, or on the TV screen, where we are passively driven in an active world. In virtual reality elements look realistic, they change their characteristics and have almost real-world unpredictability. Use of virtual reality: Virtual reality is not only implemented in gambling dens and the entertainment industry but also in manufacturing processes (cars, furniture etc.), military applications and medicine. Especially the last two areas are strongly correlated, because telemedicine or telesurgery was originated for military reasons to operate on war victims from a secure distance or to perform surgery on astronauts in an orbiting space station. In medicine and especially neurosurgery virtual-reality methods are used for education, surgical planning and simulation on a virtual patient.

Integration of generic indicators for quality management in hospital information systems

Hospital information systems may contribute in different ways to quality management activities such as monitoring of quality indicators. Most existing quality management activities in hospitals are adjusted to a special medical field or particular disease. These activities often run simultaneously with other procedures and the documentation of patient care. To determine an interdisciplinary integrated quality management procedure, a pilot study was carried out at the Neurosurgery Department and Neonatology Division of the Medical Center of the University of Heidelberg. Predefined generic indicators that may be integrated in an existing information system and used in hospital routine were the basis of this project. The aim of the study was to support the quality management with periodic reports of these indicators. The pilot study showed that there were barriers along the path to an integrated generic quality management. To meet the requirements of routine monitoring, using predefined generic indicators of hospital care, much integration effort, directed at organizational aspects of information processing and information systems architecture, is still needed.

Acute posttraumatic paraplegia associated with asymptomatic thoracic meningioma

SummaryA case of a patient with acute paraparesis after compression fracture of the twelfth vertebra with progressive neurological deterioration is reported. The occurrence of clinical asymptomatic thoracic meningioma and coincidence with posttraumatic compression fracture of the vertebra at the same level resulting in acute paraparesis is extremely rare.