Invasive Techniques In Neurosurgery Research Articles

T142. Intraoperative electrophysiological neuro-monitoring in neurosurgery: Preliminary experience, pitfalls, theoretical and practical limitations

Introduction Intraoperative neuro-monitoring is one of the minimally invasive neurosurgery techniques to reduce the risk of intraoperative damage to the nervous system, thereby reducing the risk of postoperative neurological deficits. Neuro-monitoring consists on the intraoperative recording of the activity of the nervous system. Several recordings technics can be made: somatosensitive evoked potentials (SEP), motor evoked potentials (MEP), EMG, electrocorticography, auditory evoked potentials (AEP), and brainstem evoked potentials, the study of the D wave. Methods We report our preliminary experience and discuss the value of these recordings technics in neurosurgery. Results The series include thirty-six cases: twenty cases of awake surgery for low-grade glioma in or near the eloquent areas, four scoliosis, two spina bifida, two traumatic cervical spines, two cases of cervical disc herniation, one lumbar neuroma, one case of facial hemi-spasm, one case of acoustic neuroma, two spinal cord tumors and one rolandic cavernoma. Conclusion Our department will continue to develop these technics in order to make our neurosurgical procedures more safe and we will insist on the multidisciplinary nature of these procedures.

Transependymal Movement of Cerebrospinal Fluid in Neurological and Psychiatric Pathological Conditions.

We retrospectively studied the anamnesis, in particular the etiology, the clinical picture, and computed tomography/magnetic resonance imaging/ultrasound data, in the dynamics of a heterogeneous group of 127 patients with neurological and psychiatric pathological conditions. We were interested in the reasons for the occurrence, the clinical value of various neuroimaging abnormalities in the white matter of the brain, including the periventricular zone, the communication of their occurrence with the possible exit of CSF outside of the limits of the ventricular system. In some of the patients investigations into the cerebral blood flow in dynamics using transcranial Doppler was studied. Also in this regard, indications for and the application of minimally invasive neurosurgery techniques for brain revascularization were investigated.

Neurosurgical treatment of cerebrovascular complications of heart surgeries and interventions.

Intracerebral haematoma and brain ischaemia are rare life-threatening complications of cardiovascular surgery. The aim of this study is to present the experience with the neurosurgical treatment of patients with cerebrovascular complications of heart surgery. Patients with brain ischaemia or intracerebral haematoma in the acute phase after heart surgery or invasive intervention operated on between 2002 and 2011 were reviewed. There were 3 patients with middle cerebral artery infarction requiring decompressive craniectomy (2 males, 1 female; mean age 54.3 years) and 5 patients with intracerebral haematoma (3 males, 2 females; mean age 55 years). The type of surgery for intracerebral haematoma was selected individually preferring minimally invasive techniques: stereotactic aspiration (2 patients), neuroendoscopy (1 patient), stereotactic craniotomy (1 patient) or classical craniotomy (1 patient). The results of decompressive craniectomy were unsatisfactory: GOS 1, 3 and 4 in 1 patient each. The results of surgery for intracerebral haematoma were GOS 5 in 1 patient, GOS 4 in 2 patients, and lethal in 2 patients. Minimally invasive neurosurgery techniques appear to be beneficial for selected patients with intracerebral haematoma after heart surgeries even when considering the limited number of patients. Decompressive craniectomy should be considered strictly individually.

From the idea to its realization: the evolution of minimally invasive techniques in neurosurgery.

Minimally invasive techniques in neurosurgery evolved in two steps. Many minimally invasive concepts like neuronavigation, endoscopy, or frame based stereotaxy were developed by the pioneers of neurosurgery, but it took decades till further technical developments made the realization and broad clinical application of these early ideas safe and possible. This thesis will be demonstrated by giving examples of the evolution of four minimally invasive techiques: neuronavigation, transsphenoidal pituitary surgery, neuroendoscopy and stereotaxy. The reasons for their early failure and also the crucial steps for the rediscovery of these minimally invasive techniques will be analysed. In the 80th of the 20th century endoscopy became increasingly applied in different surgical fields. The abdominal surgeons coined as first for their endoscopic procedures the term minimally invasive surgery in contrast to open surgery. In neurrosurgery the term minimally invasive surgery stood not in opposiotion to open procedures but was understood as a general concept and philosophy using the modern technology such as neuronavigation, endoscopy and planing computer workstations with the aim to make the procedures less traumatic.

Improvement of teaching methods of minimally invasive neurosurgery

Minimally invasive neurosurgery techniques developing by leaps and bounds in the past few years,which is to be a great challenge for the clinical teaching of neurosurgery.Based on their own actual,neurosurgery department of the Children's hospital of Chongqing medical university enriched the teaching contents,improved teaching methods and trained microsurgical techniques for doctors at various levels,meanwhile,it strengthened participants'sterile awareness,set good team spirit,developed individualized assessment standards and achieved good results. Key words: Neurosurgery; Minimally invasive; Teaching

Endo-Neuro-Sonography: First clinical Series

Purpose: The step from micro-neurosurgery toward Endo-Neuro-Surgery meant a step to a minimally invasive technique, but at the same time decreased its safety, which limits its applicability. The goal to further development had therefore been, to make neuro-endoscopy safer. After laboratory work, in a first series of 65 patients with a broad variety of lesions, a sono – catheter for trans-endoscopic imaging was applied for the first time in neurosurgery. Methods and Materials: A trans-endoscopic sono-catheter (Aloka Deutschland GmbH, Dusseldorf/Germany) with a diameter of 1.9mm (6F) and 2.5mm (8F) was used and introduced into the working canal of an endoscope. The image produced by the probe is a 360° scan (-brain radar“) displayed on a monitor, on which some parameters can be varied to get best view of different anatomical structures. Results: In 51 cases intraoperative imaging was the main reason for investigation and in 15 cases neuronavigation was in the focus of interest. In 20 cases of tumor resection control, targeting a visualized remnant was necessary. ENS proved in this small series to make neuroendoscopy safer and easier by online and real-time imaging with high resolution. There are limitations and artifacts which should reveal themselves in laboratory and clinical experience. Conclusions: Endo-Neuro-Sonography now as it stands, is a technique, which can contribute to the concept of minimally invasive techniques in neurosurgery, as this presentation does describe. Literature: Resch, K.D.M. Endo-Neuro-Sonography: trans-endoscopic sonography for neurosurgery. Springer 6/2005

Minimally invasive techniques in neurosurgery: the transoral transpharyngeal approach to the brain.

In 30 cases, an analysis of the transoral transpharyngeal approach to the ventral brain stem was made. All preparations were performed in situ using microscopic and endoscopic methods. Modern imaging techniques and computer-assisted approach planning were also applied and discussed. To show the subarachnoidal cisterns and receive a realistic impression of the tissue, the preparation was performed 26 times in non-fixed cases. To use currently available equipment safely, it is important to take anatomical details into account when determining the size and type of the clivus window to be used. Preparation of the preclival tissue is the most difficult step. It requires a precise approach plan to ensure safe closure. This selective approach gives the best access to the lower ventral brainstem, without any of the problems associated with other approaches to the same region. The transoral transpharyngeal approach is described here within the context of minimally invasive techniques, in particular endoscopy, modern imaging methods, and computer-assisted approach planning.

Concurrent three dimensional neuroendoscopy: initial descriptions of application to clinical practice

The authors report a consecutive series of 10 patients who presented with signs and symptoms caused by tectal tumors. Clinical findings, radiographic features, neuroendoscopic management strategies, and histological findings are reported and discussed. Since January 1990, 11 neuroendoscopic procedures were performed in 10 patients who harbored tectal tumors. The patients were followed for an average of 5 years (range 2 months to 12 years), and a retrospective study was conducted in which case notes, radiological findings, operative notes, and histopathological findings were assessed. Magnetic resonance (MR) imaging was performed, and the images were used to classify patients into three groups: those with hypertrophy of the tectum in whom isointensity appeared on T1-weighted images (Group 1); those with a tectal tumor occupying the cerebral aqueduct in whom decreased signal intensity appeared on T1-weighted images, as well as no enhancement after gadolinium administration (Group 2); and those with a tectal tumor in whom mixed signal intensity appeared on T1-weighted images and conspicuous evidence of contrast enhancement (Group 3). The results of histological examination were consistent with MR imaging features: in Group 1, glial tissue or gliosis; in Group 2, benign astrocytoma; and in Group 3, malignant astrocytoma. Cerebrospinal fluid diversion was the only surgical treatment that provided relief from obstructive hydrocephalus. One patient in Group 3 underwent radiotherapy and subsequent partial tumor removal under neuroendoscopic guidance. Thereafter, the tumor remained in decline. All patients had normal intellectual status after undergoing surgery in which a neuroendoscope was used. Neuroendoscopic procedures can provide histological diagnosis, define the tumor-midbrain interrelationship, and be highly effective in treating obstructive hydrocephalus and in removing tectal tumors. This procedure may receive clinical application as a new management strategy for tectal glioma.

The thorny road to minimally invasive techniques in neurosurgery.

This article is a brief personal account of a neurosurgeon who started his career in 1950. In spite of the subjective nature, this paper also attempts to provide some objective evidence to the history of our specialty. The terrible pain-causing pneumoencephalography and percutaneous carotid angiography, indispensable of the neurosurgery yesterday, seem to be a nightmare even for a physician today. The psychological stress of a patient at a brain operation in local anaesthesia was enormous, not to speak about the vegetative instability inherent with this anaesthesiological modality. The technical and scientific progress in the last decades, the modern diagnostic methods, the introduction of microsurgical technique and the modern anaesthetical methods and intensive care brought about an important change in the strategy and tactical considerations of neurosurgical interventions. Today the aim of our operations is not only to save life, but to improve the quality of life of the patient. Our surgical policy is directed by the knowledge of microscopical anatomy, the knowledge of arachnoidal membranes and cisterns and the introduction of microneurosurgical techniques.