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At least 613 records · Page 34Linked to original sources

Endoscopic resection of a subthalamic cavernous angioma: technical case report.

Endoscopic resection of a cavernous angioma at the subthalamic region was performed in a 33-year-old woman who presented with diplopia and progressive hemiparesis caused by recurrent hemorrhages. The entire surgical procedure was done through an 8-mm guiding tube inserted stereotactically from a frontal burr hole via an approach that traversed the anterior limb of the internal capsule. The patient's symptoms improved after surgery. This is believed to be the first report describing successful resection of a cavernous angioma located at the subthalamic region.

Adult↗

Neuroendoscopic management of pineal region tumours.

The management of pineal tumours remains controversial. During 1994 we treated four consecutive adults (16-44 yrs) harbouring a pineal tumour with a neuroendoscopic procedure. All of them presented with hydrocephalus. Pre-operative workup included cranial computerized tomography (CT), craniospinal magnetic resonance imaging (MRI) and serum levels of biological tumour markers. The endoscopic procedure consisted of a third ventriculostomy followed by biopsy with a flexible, steerable neuroendoscope. Histological diagnosis was achieved in three patients who no longer required a shunt device. Recorded complications were: bleeding during ventriculostomy that prevented us from obtaining a good sample for biopsy, short-term memory loss that cleared over a two-week period, and transient increase of pre-operative hemiparesis. Complications and morbidity are emphasized so as to be avoided with further technical experience. Neuroendoscopy affords a minimally invasive way of reaching three objectives by one-step surgery in the management of pineal region lesions: 1) CSF sample for analysis of tumour markers. 2) Treatment of hydrocephalus by third ventriculostomy. 3) Several biopsy specimens can be obtained identifying tumours which will require further open surgery or adjuvant radiation and/or chemotherapy.

Adolescent↗

Real-time CT-guided spinal biopsy with a disposable stereotactic device: a technical note.

We compared eight spinal needle biopsy procedures performed with an investigational disposable real-time stereotactic device and eight spinal needle freehand biopsies in which a standard technique was used, to determine whether the investigational device added value to the procedure. The device uses a simple stereotactic diaphragm pattern to define two vector points. The procedures in which the device was used were completed in 38% less time, using 50% fewer images, with considerably improved spatial accuracy and increased operator confidence, despite the device learning curve.

Adult↗

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

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.

Equipment Design↗

A new technique for attaching a stereotactic frame to the head: technical note.

The aim of this study was to develop a device which allows an intermediate, painless fixation of a stereotactic frame prior to definite pin fixation. To stabilize the stereotactic frame rubber coated metal springs were used. By testing the springs on 30 volunteers with different head diameters and circumferences the optimal shape was determined. In the clinical setting 15 patients undergoing stereotactic surgery were tested, stability and patient's convenience were measured. The procedure was well tolerated and measurements revealed symmetric distances between head and frame. Therefore these metal springs are a useful accessory to the Leksell stereotactic system.

External Fixators↗

Hyperthermia catheter implantation and therapy in the brain. Technical note.

For the treatment of malignant gliomas, a technique for implanting hyperthermia catheters was developed that utilized a stereotactic template and head-stabilization frame mounted on a computerized tomography (CT) scanner. Computerized tomography scans were used to measure tumor dimensions and to determine the number, implantation depths, and active heating lengths of the catheters, which were implanted through twist-drill holes while the patient was in the CT room. Heat was subsequently delivered via implanted catheters using a computer-controlled hyperthermia system, which partially compensates for heterogeneous and time-varying tumor blood flow.

Brain Neoplasms↗

Neurosurgeons and ideas before their time.

As a complementary inquiry to previous studies on citation analysis in neurosurgery, a group of ideas before their time has been arbitrarily selected by the author from 3792 first-authored papers written between 1897 and 1980 by 50 of the first American neurosurgeons. There were eight neurosurgeons who proposed 12 original theories or procedures whose importance was not recognized at the time of publication. Although the value of these ideas was not initially judged to be significant, these concepts became a part of the intellectual consensus of neurosurgery or related disciplines after varying periods of time. Technical constraints constituted the most important reason for delayed recognition of these innovative and creative ideas. Other factors were an unsuitable medium of communication, fixed scientific attitudes, prestige of previous authors, incomplete literature review by later authors, and a failure to verify observations by other investigators. The question is raised as to whether these factors might continue to affect present and future clinical investigation and laboratory research in neurosurgery.

Aneurysm↗

Multitarget stereotactic core-needle breast biopsy (MSBB)--an effective and safe diagnostic intervention for non-palpable breast lesions: a large prospective single institution study.

Multi-target stereotactic core-needle breast biopsy (MSBB) with large core needles is a modern and effective method to quickly determine the histologic nature of non-palpable breast lesions in an easy ambulatory setting. The number of patients with mammographically detectable, suspicious breast lesions is constantly increasing due to enhanced breast cancer awareness in Western female populations and with expanding screening mammography activities. MSBB is a minimally invasive diagnostic procedure, performed on an ambulatory basis under local anaesthesia in the prone position on a specially constructed stereotactic biopsy table. The patient is able to resume normal activities 1 h after the biopsy procedure. Technical and medical complications are extremely rare. In our study, we analysed the histological results of 426 MSBB procedures in 389 consecutive female patients during the years 1998-2002, and in 91 cases we were able to compare the histologic results of MSBB with the definitive histology of subsequent excisional biopsies. MSBB was technically successful in 415 out of 426 procedures (97.4%). The sensitivity for malignancy was 94.6% (87 out of 92). MSBB, therefore, is to be qualified as a remarkably reliable, patient-friendly and economic diagnostic breast intervention and was well tolerated and highly accepted by virtually all female patients involved in this single-institution feasibility and effectiveness study.

Adult↗

Clinical and economic consequences of early discharge of patients following supratentorial stereotactic brain biopsy.

OBJECT: The goal of this study was to determine the clinical and economic consequences of early discharge (< 8 hours) of patients following stereotactic brain biopsy (SBB). METHODS: The records of all patients who underwent percutaneous SBB at The Cleveland Clinic Foundation, a tertiary care teaching hospital, during 1994 and 1995 (Group A) were retrospectively reviewed to collect data on the nature and timing of perioperative (< 48 hours) clinical and radiological complications. Biopsies were performed using image-guided stereotaxy either with or without a frame. Based on the results, guidelines for early discharge of patients following SBB were implemented. Information on the nature and timing of perioperative complications was also collected prospectively in all patients who underwent percutaneous SBB from January 1996 through July 1998 (Group B). Hospital financial records for patients who underwent SBB in 1997 and 1998 were also reviewed and assessed for net revenue stratified by discharge status: early discharge (< 8 hours), extended outpatient observation (> or = 8 and < 24 hours). and inpatient hospitalization (> or = 24 hours). In Group A, 130 biopsies were performed. There were five serious complications (3.8%), of which four were transient, and there was one death (0.8%). The death and any sustained deficit occurred in patients in whom a clot had been demonstrated on postoperative CT scans. All complications were detected within 6 hours after surgery. Intraoperative bleeding occurred in 12 patients (9.2%), but was associated with only 40% of cases in which hemorrhage appeared on postoperative CT scans. Guidelines for early discharge (< 8 hours) following SBB were developed and stipulated the absence of the following: 1) intraoperative hemorrhage; 2) new postoperative deficit; and 3) clot on a postoperative CT scan. In Group B, 139 biopsies were performed. There were three serious complications (2.2%), one of which was sustained due to a clot that had been demonstrated on the postoperative CT scan. All complications were detected within 6 hours postsurgery. There were no deaths in this group. Intraoperative bleeding occurred in 11 patients (7.9%), requiring intraoperative craniotomy to control bleeding in one case. Hospital financial records were available for 96 patients, of whom 22 were discharged from the hospital early, 11 were observed for an extended outpatient period, and the remainder were retained for inpatient hospitalization. Average net hospital incomes on technical charges for patients in the inpatient hospitalization, extended outpatient observation, and short-stay (early discharge) groups were $1778, $1175, and $1219, respectively, in 1997, but declined to -$889, -$1339, and $671, respectively, in 1998. The ratios of indirect costs to direct technical costs were 132.5%, 128.7%, and 103.7%, respectively. CONCLUSIONS: Early discharge of patients following SBB of supratentorial lesions is safe in the absence of excessive intraoperative bleeding, new postoperative deficit, and clot on a postoperative CT scan. Extended outpatient observation (8-23 hours) is not clinically necessary and may be economically prohibitive in the setting of a teaching hospital.

Biopsy↗

Ontogeny of human striatal DARPP-32 neurons in fetuses and following xenografting to the adult rat brain.

After a number of reports indicating positive clinical outcome of intrastriatal transplantation of fetal ventral mesencephalic tissue into patients with Parkinson's disease, the time may have come to consider the possibility of using this technique to treat patients with Huntington's disease. On the basis of the available literature, the Network of European CNS Transplantation and Restoration has established a program aiming at defining the optimal conditions for such clinical trials. The present study, conducted within this framework, pursued the goal of providing information concerning the period of striatal neuronal ontogeny in humans, taking into account the technical and legal requirements imposed by the clinical procedure of neural transplantation using human tissue. On this basis, it aimed at establishing a reliable dissecting method for the intrastriatal grafting of human fetal striatal neurons. The ontogeny of medium-spiny neurons within the developing striatum was first studied in a series of human fetal brains, 5 to 10 weeks postconception, using immunocytochemical detection of DARPP-32. Immunoreactive neurons were observed in fetuses at 7 weeks of age and older. They were mostly localized in clusters, packed in the lateral ganglionic eminence. Over a 2-week-long period, DARPP-32 neurons increased in number. Their morphology remained poorly differentiated, however, with small cell bodies, few branched dendrites, and variable intensity of immunostaining. Based on these findings, selective dissection of the lateral ganglionic eminence was carried out. This tissue was stereotaxically implanted into the striatum of immunosuppressed adult rats previously lesioned. Two months postgrafting, DARPP-32 neurons were observed as discrete patches, embedded within areas of essentially DARPP-32-negative tissue. Up to 2 months after grafting, neurons remained poorly differentiated in general, with only a few neurons exhibiting a dense immunoreactivity and long processes. These results indicate that striatal DARPP-32-immunoreactive neurons are present in the lateral ganglionic eminence in fetuses as soon as 7 weeks postconception. The striatal tissue can be dissected out and successfully transplanted. Within the grafts, neuronal differentiation appears to be a very long process, suggesting that many months might be necessary for these neurons to become functionally integrated into an adult host brain.

Animals↗

[Prospect of neurosurgical approach to Parkinson's disease in the 21st century].

After a brief review of the past and present status of stereotactic surgery, prospect of neurosurgical approach to Parkinson's disease in the 21st century was considered. The stereotactic surgery has progressed markedly in its technical and theoretical aspects due to the rapid development of the basic neuroscience and computerized imaging technique. Although there are some points to be clarified and estimated in the future, these new tendencies will stand to the next century, and further progress will be achieved if it contains some truth in the light of the modern neuroscience. Also it should be clinically effective, safety and smart. The idea of stereotaxy since the beginning, namely the maximum effect with minimal damage of the human brain always holds true.

Brain↗

Stereotactic investigation of limbic epilepsy using a multimodal image analysis system. Technical note.

A methodology has been developed for stereotactic investigation of limbic epilepsy using an image-analysis system that simultaneously displays different structural and functional images of the brain. The validity and accuracy of this system were established with phantom studies. Surgical planning and electrode implantation are guided by stereotactic magnetic resonance imaging, digital subtraction angiography, and position emission tomography. This methodology provides the spatiotemporal relationship of cerebral structure and function necessary to identify seizure onset and propagation in human limbic system epilepsy.

Brain Mapping↗

Interstitial hyperthermia and iridium brachytherapy in treatment of malignant glioma. A phase I clinical trial.

An oncolytic effect of hyperthermia in the 42 degrees to 43 degrees C range has been previously demonstrated in cell culture and animal models. To apply this modality clinically, an interstitial microwave antenna array system has been developed for the delivery of controlled hyperthermia to an intracranial tumor volume, and a Phase I clinical trial involving six patients with malignant gliomas was undertaken. The protocol to study technical feasibility and patient tolerance combined interstitial iridium-192 irradiation and interstitial hyperthermia with 60-minute hyperthermia sessions immediately before and after brachytherapy. After-loading catheters suitable for both treatment modalities were implanted using a computerized tomography-assisted technique. Thermometry data confirmed the ability of a microwave antenna system to achieve reliable temperature distributions, and reasonable patient tolerance was documented.

Adult↗

Should all breast cancers be diagnosed by needle biopsy?

BACKGROUND: Although much data support the National Quality Forum recommendation that breast cancers should be diagnosed by needle biopsy before surgical resection, the exclusion criteria for those that may not be suitable have yet to be defined. METHODS: We reviewed all patients treated over the past 3 years at the Yale Breast Center to determine the percentage of patients not diagnosed by needle biopsy, and why. RESULTS: Reasons for the 17% of 630 patients who were not diagnosed by needle biopsy were as follows: inability to cooperate (1%); small or superficial lesion less than 1 cm that technically was easier to excise in the office (4%); bloody discharge without clinical or mammographic mass (1%); lesion adjacent to implant (.5%); a mammographic lesion that was too posterior, too superficial, or too faint to be performed stereotactically (5%); or patient preference (5%). CONCLUSIONS: Needle biopsy is the preferred method of diagnosis in most cases, but there are valid reasons why all breast cancers will not be diagnosed in this fashion.

Biopsy, Needle↗

A device to aid in the application of stereotactic headframes: technical note.

It is sometimes difficult to apply the headframes of stereotactic systems in awake patients who are lethargic or demented or in patients who are very sensitive to the discomfort of local anesthetic injection. A device for external stabilization of the stereotactic system during its application to the head is described. This device, a modification of the Somi brace, is easy to apply, allows for adjustment of the base ring in all planes and provides sufficient stability even in obtunded or uncooperative patients. This device simplifies and makes more precise the application of the stereotactic headframe and may be of considerable utility in stereotactic surgery.

Equipment Design↗

Linear accelerator radiosurgery of three-dimensional irregular targets.

Current radiosurgical techniques allow concentration of radiation from external sources into spherical targets. Nonspherical target volumes require a modification of the irradiation technique. Moreover, isodose shaping is sometimes necessary to spare nearby important radiosensitive structures. To meet these prerequisites we have introduced some technical refinements: (1) computer-controlled rectilinear translations of the target in combination with different angular positions of the source and (2) computer-controlled rotations of the target around a vertical axis in combination with different angular positions of the source. The first solution has proven efficient for treating irregular targets, while the second one was employed for focusing the radiation dose inside volumes obtained by rotation of ellipses.

Brain Neoplasms↗

Transcerebellar biopsy of posterior fossa lesions using the Leksell gamma model stereotactic frame.

We describe a technical modification of the Leksell gamma stereotactic system that enables a direct transcerebellar biopsy of posterior fossa lesions. By using an additional pair of long (14 cm) posts placed in the posterior positions of the frame, the frame can be positioned low enough to allow for direct approaches to the posterior fossa. With the patient in the semisitting position, a biopsy can be performed under local anesthesia. We have found this technique provides a simple, comfortable, and effective biopsy of posterior fossa lesions.

Biopsy, Needle↗

Implantation of intracerebral depth electrodes for monitoring seizures using the Pelorus stereotactic system guided by magnetic resonance imaging. Technical note.

The Pelorus stereotactic system guided by magnetic resonance imaging was used to implant intracerebral depth electrodes for monitoring seizure activity. This stereotactic system is frameless and does not require the use of a computer. It is based on the concept of a ball-and-socket type stereotactic arc director and uses the center-of-arc principle to establish a trajectory for electrode placement. The system not only allows the use of the orthogonal approach, but also provides ample working space and flexibility to choose different entry points and trajectory angles.

Adolescent↗