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At least 595 records · Page 33Linked to original sources
PubMed1987

Accessory to the Talairach's apparatus for orthogonal approaches. Technical note.

A stereotactic device is described which, without modifying the main characteristics of the Talairach's stereotactic apparatus, increases its flexibility in orthogonal approaches. This accessory, which replaces the double-grid system, permits any orthogonal access on the X and Y coordinates and insertion of any type of electrode, catheter or probe, without the constraints of the double grid holes. Its use in different stereotactic operations (brain tumor biopsy or curietherapy, implantation of intracerebral depth electrodes for stereo-EEG recording) proved its wide working capability and great reliability.

Humans↗
PubMed1991

Stereotactic suboccipital transcerebellar biopsy under local anesthesia using the Cosman-Roberts-Wells frame. Technical note.

Previously reported suboccipital transcerebellar stereotactic biopsy methods, performed with the patient in the prone position, have required general endotracheal anesthesia. A technique is described for performing such biopsies with the patient in the lateral decubitus position, under local anesthesia. Phantom planning and routine computerized tomography graphics allow the selection of a safe entry point and intra-axial trajectory to the lesion. The time required for data acquisition and the operative procedure itself compares well with that of more routine biopsy techniques.

Anesthesia, Local↗
PubMed1976

Vitreoretinal and anterior segment surgery through the pars plana: part I.

Instrumentation and clinical experience dealing with intraocular surgery through a pars plana approach have advanced rapidly during the past 5 years. These techniques have been used to successfully treat a number of ocular disorders. Considerable experience with this form of surgery has accumulated, and the results and incidence of complications are similar among centers. Additional refinements in instrumentation and surgical techniques will probably expand the capabilities and further improve the results of pars plana surgery. However, we are rapidly approaching a point at which the primary limiting factor will be the pathophysiology of ocular diseases rather than instrumentation or surgical skill. The ability to improve vision by removing persistent opacities of the ocular media has been demonstrated, and follow-up of 2 more years has shown that the eye can continue to function well after excision of the formed vitreous. The indication for vitreous surgery which has proven to be the most difficult and hazardous is treatment of complicated rhegmatogenous retinal detachments in which elevated, mobile retina presents special problems. The role of vitrectomy in the management of proliferative diabetic retinopathy and early management of penetrating injuries involving the posterior segment are the primary clinical-research objectives for the immediate future. In these conditions vitrectomy may be useful to alter the course of progressive vitreoretinal pathology as well as being used to treat previously existing complications. Finally, our experience has shown that risk of significant complications is present in every case of surgery performed through a pars plana approach. The incidence of mechanical complications can be minimized by careful attention to detail during surgery, but complications cannot be eliminated. Retinal detachment is the most frequent potentially blinding complication, and the vitreous surgeon should be skilled in management of retinal breaks and retinal detachment. Also, there are biologic complications, including rubeosis iridis, which may occur following technically successful surgery in certain eyes. Rubeosis iridis is a major problem in diabetic eyes because it can destroy the functional results of an otherwise successful operation, and no effective treatment is now known. Hopefully, research efforts will improve our understanding of the pathogenesis of this disorder and permit us to develop effective means of prophylaxis or treatment.

Ciliary Body↗
PubMed1992

Stereotactic, angiography-guided clipping of a distal, mycotic intracranial aneurysm using the Cosman-Roberts-Wells system: technical note.

We describe the use of stereotactic, angiographic guidance for localization and clipping of a small, distal intracranial bacterial aneurysm. The technique uses the commercially available Suetens-Gybels-Vandermeulen angiographic localizer with the widely used Cosman-Roberts-Wells stereotactic system. This method is simple and easy to use and significantly decreased the operative time. It may be quite useful for surgically treating mycotic and other peripheral aneurysms.

Adult↗
PubMed2003

In vivo modulation of hippocampal epileptiform activity with radial electric fields.

PURPOSE: Electric field stimulation can interact with brain activity in a subthreshold manner. Electric fields have been previously adaptively applied to control seizures in vitro. We report the first results from establishing suitable electrode geometries and trajectories, as well as stimulation and recording electronics, to apply this technology in vivo. METHODS: Electric field stimulation was performed in a rat kainic acid injection seizure model. Radial electric fields were generated unilaterally in hippocampus from an axial depth electrode. Both sinusoidal and multiphasic stimuli were applied. Hippocampal activity was recorded bilaterally from tungsten microelectrode pairs. Histologic examination was performed to establish electrode trajectory and characterize lesioning. RESULTS: Electric field modulation of epileptiform neural activity in phase with the stimulus was observed in five of six sinusoidal and six of six multiphasic waveform experiments. Both excitatory and suppressive modulation were observed in the two experiments with stimulation electrodes most centrally placed within the hippocampus. Distinctive modulation was observed in the period preceding seizure-onset detection in two of six experiments. Short-term histologic tissue damage was observed in one of six experiments associated with high unbalanced charge delivery. CONCLUSIONS: We demonstrated in vivo electric field modulation of epileptiform hippocampal activity, suggesting that electric field control of in vivo seizures may be technically feasible. The response to stimulation before seizure could be useful for triggering control systems, and may be a novel approach to define a preseizure state.

Amplifiers, Electronic↗
PubMed1999

Intra-operative localisation of skull base tumours. A case report using the ISG viewing wand in the management of trigeminal neuroma.

Deep-seated skull base tumours provide as much a challenge to the surgeons' skills of localisation as to his technical abilities during the resection. These lesions are frequently inaccessible and lie adjacent to vital structures requiring extensive cerebral retraction for adequate exposure and direct visualisation. The ISG viewing wand is a newly developed image guidance system to aid direction of the operative approach and localisation of intracerebral pathology. We discuss its use in the management of a trigeminal neuroma.

Cranial Nerve Neoplasms↗
PubMed1992

Direct skull marking for a pre-operative localization in regional cerebral surgery. Technical note.

A method is described in which an open neurosurgical target is pre-operatively marked on the skull of a patient. A target point of the scalp surface localized from neuroimaging studies is transferred onto the skull by an injection of pyoktanin blue. Its accuracy and reliability is far superior than that of the usual scalp marking. The method is simple, practical, and allows a smaller, regional craniotomy with the advantage of minimum operative invasiveness.

Adult↗
PubMed1994

A method for monitoring intracranial temperature via tunneled ventricular catheter: technical note.

A simple technique for monitoring intracerebral temperature in humans via a ventricular catheter is described. This differs from a previously described method by enabling such measurements to be accomplished with a commercially available thermistor, a standard ventricular catheter, and common hospital supplies. In contrast to the earlier device, this system allows for the subcutaneous tunneling of the distal ventricular catheter. This is an easily assembled and cost-effective technique with which to conduct investigations on human intracerebral temperature.

Brain Injuries↗
PubMed1983

Probe holder for stereotactic surgery in the CT scanner. A technical note.

The necessity for intraoperative computer tomographic (CT) visualization of stereotactic probes and for the immediate assessment of the results of therapeutic intervention has brought about the integration of CT and stereotactic surgical sites. In order to perform intraoperative CT imaging, a simple mechanical device has been developed to hold a probe at the target. This device replaces the conventional semicircular arc that was used to guide the probe to the target during stereotactic procedures. Intraoperative imaging during a CT stereotactic procedure was accomplished without significant artifacts.

Brain Diseases↗
PubMed1985

[The harpoon technic in excision of subclinical mammary lesions. Preliminary results].

Preliminary results are reported of the use of a surgical technique since April 1983 for excision of subclinical mammography-observed anomalies. The procedure involves the insertion of a harpoon-shaped metallic thread, after detection by mammography, to obtain guidance of surgical procedures. Preliminary results in 36 cases included the detection of 10 cancers, confirming documented data in this field, and it would therefore appear worthwhile continuing along this pathway of early diagnosis.

Adult↗
PubMed1997

Core biopsy for microcalcifications in the breast.

BACKGROUND: The conventional method of dealing with clustered mammographic microcalcification in the breast when it is of uncertain aetiology is to undertake either a short-term mammographic review or to surgically excise the abnormal area and submit it for histological examination. Stereotactic wide-bore needle biopsy (core biopsy) of microcalcifications is a suitable alternative to surgical biopsy and experience with this technique forms the basis of the present study. METHODS: Percutaneous core biopsy has been used at the Wesley Breast Clinic as a means of assessing clustered calcification in 297 cases from November 1992 to October 1995. The procedure is done under local anaesthesia as an outpatient procedure using a stereotactic attachment to a standard mammography unit. RESULTS: A diagnosis of frank malignancy was made on core samples in 22 cases (7.4%), and in all of these malignancy was confirmed at open surgical biopsy. In a further six women in whom the core biopsy was reported as 'suspicious of malignancy', open surgical biopsy confirmed malignancy in three women, lobular in situ carcinoma was found in two women, and atypical ductal hyperplasia in one woman. In two instances the core sample was reported as showing atypical ductal hyperplasia and in those cases, this was confirmed at open surgical biopsy. In 265 cases (89%) the histology of the core revealed appearances of benign breast tissue. Open surgical biopsy has been undertaken in only six of these cases, but in all instances the histology has confirmed a benign process. In the two remaining cases, the procedure was considered to be technically unsatisfactory, and open surgical biopsy was recommended because of doubt about the appearance of the microcalcification. In both instances, malignancy was demonstrated. CONCLUSIONS: Core biopsy of clustered mammographic microcalcification of uncertain aetiology is recommended as a satisfactory and reliable alternative to open surgical biopsy. It is less expensive, can be done quickly, produces few complications, and does not produce subsequent mammographic distortion.

Ambulatory Surgical Procedures↗
PubMed2001

Limitations of stereotactic biopsy in the initial management of gliomas.

Stereotactic biopsy is often performed for diagnostic purposes before treating patients whose imaging studies highly suggest glioma. Indications cited for biopsy include diagnosis and/or the "inoperability" of the tumor. This study questions the routine use of stereotactic biopsy in the initial management of gliomas. At The University of Texas M. D. Anderson Cancer Center, we retrospectively reviewed a consecutive series of 81 patients whose imaging studies suggested glioma and who underwent stereotactic biopsy followed by craniotomy/resection (within 60 days) between 1993 and 1998. All relevant clinical and imaging information was reviewed, including computerized volumetric analysis of the tumors based on pre- and postoperative MRI. Stereotactic biopsy was performed at institutions other than M. D. Anderson in 78 (96%) of 81 patients. The majority of tumors were located either in eloquent brain (36 of 81 = 44%) or near-eloquent brain (41 of 81 = 51%), and this frequently was the rationale cited for performing stereotactic biopsy. Gross total resection (>95%) was achieved in 46 (57%) of 81 patients, with a median extent of resection of 96% for this series. Diagnoses based on biopsy or resection in the same patient differed in 40 (49%) of 82 cases. This discrepancy was reduced to 30 (38%) of 80 cases when the biopsy slides were reviewed preoperatively by each of three neuropathologists at M. D. Anderson. Major neurologic complications occurred in 10 (12.3%) of 81 surgical patients and 3 (3.7%) of 81 patients undergoing biopsy. Surgical morbidity was probably higher in our series than it would be for glioma patients in general because our patients represent a highly selected subset of glioma patients whose tumors present a technical challenge to remove. Stereotactic biopsy is frequently inaccurate in providing a correct diagnosis and is associated with additional risk and cost. If stereotactic biopsy is performed, expert neuropathology consultation should be sought.

Adolescent↗
PubMed1992

Marking of the stereotactic target point by a radiopaque silicone sphere. Technical note.

We present a simple but efficient technique for marking the site of a stereotactic biopsy. This is done by a radiopaque Barium impregnated silicone sphere, which is introduced through the stereotactic cannula and placed at the target point. This allows a postoperative check of the target point by computer tomography or Magnetic Resonance Imaging and offers a landmark for further stereotactic intervention as well as for planning of high precision radiotherapy. Moreover it gives information about the growing direction of a tumour. The silicone spheres are well tolerated; no complications have occurred so far.

Biopsy↗
PubMed2002

Placement of deep brain stimulators into the subthalamic nucleus or Globus pallidus internus: technical approach.

Deep brain stimulation (DBS) represents a major advance in the treatment of Parkinson's disease (PD). As more neurosurgeons enter this field, technical descriptions of implantation techniques are needed. Here we present our technical approach to subthalamic nucleus (STN) and globus pallidus internus (GPi) DBS implantation, based on 180 STN implants and 75 GPi implants. The essential steps in DBS implantation are magnetic resonance imaging (MRI)-guided stereotactic localization, confirmation of the motor territory of the target nucleus with microelectrode mapping, and intra-operative test stimulation to determine voltage thresholds for stimulation-induced adverse effects. Lead locations are documented by postoperative MRI in all cases.

Dystonia↗
PubMed1983

A new head clamp for stereotactic and intracranial procedures. Technical note.

The authors have devised a clamp to fix the head to the surgical table during stereotactic procedures for placement of depth electrodes. The main advantages of this device derive from the rigid immobilization of the head. The clamp facilitates fixation of the stereotactic frame to the head, percutaneous twist drill trephination of any site of the skull, X-ray centering with a laser beam, mobilization of contrast material during ventriculography or pneumoencephalography, and placement of epidural screws. This head clamp can also be used during craniotomies for fixation of the head and support for brain retractors.

Brain Diseases↗
PubMed2002

Stereotactic biopsy of the breast using an upright unit, a vacuum-suction needle, and a lateral arm-support system.

OBJECTIVE: This study evaluated the vacuum-suction needle (8- to 11-gauge) on an upright stereotactic machine with a lateral arm-support system. SUBJECTS AND METHODS: From July 1999 to August 2000, 185 core biopsies of the breast in 179 consecutive patients were planned in four institutions using 8- 11-gauge vacuum-suction probes on an upright stereotactic unit. Needles were stabilized and attached to the x, y, and z coordinates of the machines via a lateral arm-support system. Needle entry was made in the x-axis. RESULTS: Five patients were canceled, and 180 biopsies were performed in 174 patients while the patients were in seated (n = 171) and lateral decubitus (n = 9) positions. An average of 9.5 cores were taken (range, 5-26 cores). Targeting was successful in 176 (98%) of 180 cores. Lesions were missed because of movement associated with Parkinson's disease (n = 1), or because the mass was obscured (n = 1) or calcifications were not in the core specimen (n = 2). Findings in 152 (84%) of the biopsies were benign and 28 (16%) were malignant. Forty-one lesions underwent surgical excision and 106 underwent mammographic follow-up. Discordance was 4% (6/147). Complications included vasovagal reactions (n = 10, 5.6%), bleeding (n = 5, 3%), hematomas (n = 3, 1.7%), vomiting (n = 1, 0.6%), and technical failure (n = 1, 0.6%). CONCLUSION: Vacuum-suction needle core biopsies can be successfully performed on an upright stereotactic machine with a lateral arm attachment. Thinly compressed breasts and lesions located near the chest wall are well sampled. The vasovagal rate is higher than that on a prone table but is acceptable.

Adult↗
PubMed1998

Modification of the Talairach stereotactic system for CT-compatibility: technical note.

A modification of the Talairach stereotactic system is described which is able to incorporate CT data and provides both co-ordinate calculations, directly from the CT console screen and by a fiducial reference system. The device maintains the original base plate, thus allowing its interfacing with all the accessories of the early apparatus and its direct use in the stereotactic operating room. The instrument has shown great reliability in the localisation of brain lesions and considerable flexibility in many stereotactic operations such as biopsy procedures, brachytherapy, radiosurgery and stereotactically assisted resections.

Equipment Design↗
PubMed1995

A noninvasive thermoplastic head immobilization system. Technical note.

The authors have developed a noninvasive head immobilization system for use in neuroimaging (magnetic resonance imaging, computerized tomography, single photon emission computerized tomography, and projection angiography), neurosurgical planning, and neurosurgery. These diagnostic and surgical procedures require patient immobilization, reproducible patient positioning, and anatomical localization. The thermoplastic system described in this technical note addresses each of these requirements with a high degree of accuracy and with no bone fixation. The reproducibility of positioning and effectiveness of immobilization were evaluated using nine healthy volunteers during repeated sessions of magnetic resonance imaging. The mean axial displacement for repeated positioning was 0.6 mm (variance 0.1 mm); the mean displacement during robust patient motion in the axial direction was 1.8 mm (variance 0.9 mm).

Diagnostic Imaging↗