The initial experience with the Cosman-Roberts-Wells stereotactic system

The Cosman-Roberts-Wells stereotactic instrument is a recently developed modification, based on an arc-radius design, of the Brown-Roberts-Wells stereotactic frame utilizing the existing fixation and fiducial components of the Brown-Roberts-Wells stereotactic system to localize and verify target data. The design modification has been made with a view to facilitating technical approaches both in stereotactic biopsy and in stereotactic craniotomy, whilst encompassing the same stereotactic space. Initial experience with the Cosman-Roberts-Wells instrument is reported. Over a 5-month period 55 procedures were performed which included 40 stereotactic biopsies, five CT-guided stereotactic craniotomies, three stereotactic placements of a Bennett Ball for thalamotomy, three stereotactic implantations of intracranial electrodes for recording in drug-resistant epilepsy, three aspirations of cyst or haematoma and one implantation of a Gutin catheter for interstitial brachytherapy. There was minimal morbidity and no mortality related to operation. This frame offers rapid targeting without the need to pre-determine entry points, as well as allowing direct lateral passes and unimpeded stereotactic craniotomy.     

Endoscopic surgery for spontaneous basal ganglia hemorrhage: comparing endoscopic surgery, stereotactic aspiration, and craniotomy in noncomatose patients

BACKGROUND: This prospective study aimed to evaluate the safety, neurological outcomes, and cost-effectiveness of 3 surgical procedures for spontaneous basal ganglia hemorrhage. METHODS: Ninety noncomatose patients with basal ganglia hemorrhages were randomized into 3 groups. Group A (n = 30) underwent endoscopic surgery, group B (n = 30) underwent stereotactic aspiration, and group C (n = 30) underwent craniotomy. Waiting time of surgery, length of operation time, and blood loss were compared between all groups. On the second operative day, we evaluated the amount of residual hematoma and the hematoma evacuation rate by computed tomography scan. Surgical mortality and complications were recorded 3 months after the procedure. Neurological outcomes were evaluated by functional independence measure (FIM) score, Barthel index score, and muscle power (MP) of affected limbs 6 months after surgery. We also evaluated the cost-effectiveness of each procedure. RESULTS: There was significant delay in waiting timing of the stereotactic aspiration (172.56 +/- 93.18 minutes; P < .001). Craniotomy had the longest operation time (229.96 +/- 50.57 minutes; P < .001). Blood loss was most significant in the craniotomy (236.13 +/- 137.45 mL; P < .001). The highest hematoma evacuation rate was seen in the endoscopic surgery (87% +/- 8%; P < .01). The mortality rate was 0% in group A, 6.7% in group B, and 13.3% in group C (P = .21). The complication rate was 3.3% in group A, 10% in group B, and 16.6% in group C (P = .62). The most major complications were rebleeding and infection. The FIM score was higher in the endoscopic surgery (79.90 +/- 36.64) than in the craniotomy (33.84 +/- 18.99; P = .001). The Barthel index score was also significantly better in the endoscopic surgery (50.45 +/- 28.59) than in the craniotomy (16.39 +/- 20.93; P = .006). There was more improvement in MP of affected limbs in endoscopic surgery than in craniotomy (P = .004). Endoscopic surgery was more cost-effective than craniotomy using FIM and Barthel index (P < .02 and P < .05, respectively). CONCLUSIONS: Both endoscopic surgery and stereotactic aspiration are minimally invasive and are effective procedures with low complication and mortality rates; however, the waiting timing of stereotactic aspiration is usually longer. Endoscopic surgery may be an appropriate substitute for stereotactic aspiration. It produces good neurological outcomes and aids in rapid hematoma evacuation. Craniotomy may be used for emergency decompression of enlarged hematoma if endoscopic surgery or stereotactic aspiration is not available.     

Stereotactic microsurgical resection of intracranial tumors using the electromagnetic field focusing system.

The intense heat produced at the tip of the electromagnetic field focusing (EFF) probe at its point of contact with tissue can cut and vaporize tissue and coagulate blood vessels. As the probe is shaped like a bayonet and has a diameter of 0.3 mm at its tip, it can be used on deep structures through narrow openings, making it ideal for stereotactic craniotomy. Thirteen stereotactic craniotomy procedures using the EFF system were performed. Locations of the lesions were deep in the cerebrum, cerebellum and in the lateral ventricle. The system proved efficient with reduced blood loss and unobstructed view of deep structures. No complications resulted from the use of the system.     

Stereotactic craniotomy

Computed tomography-based stereotactic biopsy procedures for diagnosing intracranial tumors are common today. In addition, point stereotaxis is used to center a craniotomy over a superficial lesion or to find a deep one. Technical innovations have improved performance of these operations. The author describes the instrumentation and current methodology for computer-assisted stereotactic laser microsurgical extirpation of intra-axial lesions and discusses the results.     

Stereotactic craniotomy: methods and results using the Brown-Roberts-Wells stereotactic frame

Combining the power of stereotactic precision with open craniotomy in a stereotactic craniotomy technique decreases surgical time, morbidity, and postoperative hospitalization. Indications for its use are deep intrinsic masses 3.5 cm or less in diameter; small, superficial lesions otherwise difficult to localize; and lesions associated with motor, visual, or speech areas. Using the standard Brown-Roberts-Wells system allows a) precisely planned cortical entries, b) gross total lesion excisions under direct vision, c) use of probe-guided resection margins, d) small craniotomies through linear incisions, and e) use of local anesthetic alone for resections. The method and results of this universally available and relatively inexpensive technique are discussed in reference to 20 patients.     

Stereotactic biopsy for intracranial lesions: reliability and its impact on the planning of treatment

Background. The authors present a retrospective analysis of 308 computed tomography (CT)-guided stereotactic biopsies in 300 patients in order to evaluate the reliability and efficacy of the stereotactic biopsy for intracranial lesions. Method. All patients were suffering from undetermined intracranial lesions and treated at Seoul National University Hospital between January 1993 and December 1999. Age ranged from three to 79 years (mean 41); the male to female ratio was 180:120. All patients underwent CT-guided stereotactic biopsy for the histological verification and/or evacuation of the cyst using Riechert-Mundinger stereotactic system®. Findings. Histological diagnosis was made in 275 patients (diagnostic yield 91.7%). Diagnostic yield was better in group with frozen section examination during the stereotactic procedure than the group without it (p=0.01). Neoplastic lesions were more likely to be diagnosed in stereotactic biospy than non-neoplastic lesions (p=0.02). Among 30 patients who underwent craniotomy after the stereotactic biopsy, the histological diagnoses after the craniotomy were identical to those of the stereotactic biospy in 29 patients (diagnostic accuracy 96.7%). Two patients died within seven days after the stereotactic biopsy (mortality 0.6%). The postoperative new neurological deficit or aggravation of the neurological status was found in 19 patients, including transient cases of seven patients (permanent morbidity rate 3.9%). Histologically malignant gliomas and deeply-located lesions were the significant risk factors for the development of complications. In 148 cases, histological diagnosis of the stereotactic biopsy was different from the preoperative clinical diagnosis. Among these cases, the treatment plan was changed after stereotactic biopsy in 81 cases. Conclusions. Stereotactic biopsy for intracranial lesions is a reliable and relatively safe procedure. It is also a very efficacious method especially in patients who need histological confirmation for the treatment.Published online July 25, 2003     

Transnasal stereotactic biopsy of a clivus tumor. Technical note.

Computerized tomography-guided transnasal stereotactic tissue diagnosis of a lytic lesion in the clivus was performed successfully using the Cosman-Roberts-Wells frame, thus avoiding a major craniotomy. The authors recommend stereotaxis as the preferred technique for biopsy in this region.     

不同手术方法对高血压脑出血患者康复的影响

目的：探讨不同手术方法对高血压脑出血患康复影响的临床意义。方法：采用立体定向血肿排空术(34例)和骨瓣开颅术(40例)进行对照研究。结果：2组近期疗效无明显差异，远期疗效立体定向组并发症发生率低，神经功能恢复快，ADL评定优于骨瓣组。结论：微创、减压及超早期手术是高血压脑出血较佳的外科治疗方法。     

Modification of the Talairach Stereotactic System for CT-Compatibility: Technical Note

Summary 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.     

Computerised tomography guided preoperative localisation of small intracranial lesions

A simple method for preoperative localisation of small intracerebral lesions is described. Small cortical and subcortical lesions around the motor area were precisely located with computerised tomography in nine patients and these lesions were then excised through a three centimetre craniotomy.     

Stereotactic management of colloid cysts: factors predicting success

Stereotactic aspiration is a valuable surgical alternative for colloid cysts when used alone or in conjunction with microsurgical resection. Since 1981, the authors have performed computerized tomography (CT)-guided stereotactic aspiration as the initial procedure in 22 patients with colloid cysts; stereotactic aspiration alone was successful in 11 patients (50%). Of the 11 patients in whom aspiration failed, stereotactic endoscopic resection was attempted in three and was successful in one. Seven patients required a craniotomy and microsurgical removal of the cyst performed via a transcortical approach. The preoperative CT appearance in eight cases of a hypodense or isodense cyst correlated favorably with successful aspiration of the cyst in six patients. A hyperdense appearance on the preoperative CT scan in 14 cases was associated with subtotal aspiration in 13 patients; five required craniotomy for removal. Preoperative magnetic resonance (MR) imaging in eight patients provided excellent anatomical definition of the cyst and its relationship to other structures of the third ventricle, but it was not possible to correlate successful aspiration with cyst appearance on MR images with short or long relaxation time sequences. The authors' 9-year experience suggests that preoperative CT studies accurately determine size, predict viscosity, and help to define a group of colloid cyst patients for whom stereotactic cyst aspiration will likely be successful. Unsuccessful stereotactic aspiration was related to two features: the high viscosity of the intracystic colloid material (nine patients), or deviation of the cyst away from the aspiration needle due to small cyst volume (two patients). Because of its simplicity and low risk, stereotactic surgery can be offered to selected patients as the initial procedure of choice. Craniotomy can be reserved for those whose imaging studies predict failure or for those whose cyst cannot be aspirated.     

Awake craniotomy using stealth frameless stereotaxy without rigid skull fixation

The authors describe a technique using the Medtronic Stealth spinal reference array allowing awake craniotomy to be performed without cranial fixation in the Mayfield pin head rest. A Medtronic spinal reference array (four-point H-shaped LED array) is fitted to a Yasargil footplate via a three-jointed swingarm. The Yasargil footplate is directly attached to the cranium after craniotomy and following stereotactic registration the patient is awakened. The patient is free to move his head during the procedure as the reference array does not move in relation to the cranial contents and the fiducials, preserving accuracy.     

Technical application of stereotactic irradiation in malignant brain tumors.

This study reports the technical application of stereotactic interstitial brachytherapy for malignant gliomas in two groups of patients. Group I consisted of 2 patients who had undergone previous debulking brain surgery; group II were 3 patients who were not candidates for craniotomy because their tumors were surgically inaccessible. The stereotactic implantation technique in group I was somewhat complicated due to the irregular shape of the residual tumor masses. Sophisticated pre-implantation planning was necessary for adequate coverage of the entire tumor volume. In this series, inoperable tumors were also successfully implanted with excellent results.     

A review of stereotaxy and lysis for intracranial hemorrhage

Intracranial hemorrhage represents a significant cause of human morbidity and mortality, leaving as many as 80% of patients either dead or disabled. Techniques for management of hemorrhage include optimal medical care, craniotomy, endoscopy, and stereotaxy. This work reviews the history of cranial stereotaxy for evacuation of nontraumatic hemorrhage beginning with techniques for mechanical disruption of the coagulated hemorrhage modeled after Archimedes screw. We discuss the properties of urokinase and tissue plasminogen activator, which have been utilized for lysis, and the outcomes after stereotactic fibrinolytic evacuation of intracerebral hemorrhage. The ongoing clinical trials evaluating the efficacy of stereotactic fibrinolysis are also discussed.     

Stereotactic indications for neuroradiological differential diagnosis

Summary The modern neurodiagnostic techniques of MR imaging, CT scanning and angiography provide valuable morphological information that, although highly sensitive to tumour localisation, still lacks comparable specificity as to the exact histological nature of those lesions demonstrated. Biopsy remains necessary.To patients with potentially inoperable lesions or lesions best treated by chemotherapy or irradiation, modern techniques of neurosurgery now offer the option of precise stereotactic biopsy through small twist-drill burr holes as opposed to open biopsy. The interrelationships between MR, CT, angiography and stereotactic biopsy and their respective roles in the establishment of a definitive diagnosis are discussed.     

Stereotactic support in the excision of brain tumors. Technical note

The surgical resection of deep-seated brain tumors may be facilitated by CT guided stereotactic methods. The Authors present a procedure of preoperative localisation and delimitation of the border of a neoplastic mass facing important functional areas. Ideally tumor excision should not be extended beyond that boundary which for this reason is targeted and is stereotactically labeled using non diffusible dyes.     

Stereotactic craniotomy in the resection of small arteriovenous malformations

Surgical resection of 10 obscure arteriovenous malformations (AVM's) was accomplished with craniotomy guided by computerized tomography (CT) or angiography and the use of the Brown-Roberts-Wells stereotactic frame. Stereotactic craniotomy was invaluable for resection of the following types of AVM's: 1) AVM's with a nidus less than 2 cm in diameter, 2) AVM's located in an eloquent area of the brain, and 3) AVM's located deep in the brain. Stereotactic localization of these AVM's on preoperative radiological studies provides a precise route to the nidus, often avoiding important areas of the brain. This series included six male and four female patients with a mean age of 32 years. All patients presented with an intracerebral hemorrhage, from which eight made a complete neurological recovery prior to surgery. Two AVM's were located on the cortex, three were found subcortically, and five were situated near the ventricles or in the deep white matter. As a guide, angiography was used in six cases and CT in four cases. In each instance, the study providing the best image of the AVM nidus was employed. Postoperatively, no neurological deficits were found in eight patients and, in the two patients with preoperative deficits, neurological improvement was observed after recovery from surgery. Postoperative studies revealed complete removal of the AVM in all patients, and all lesions were confirmed histologically. The authors conclude that stereotactic craniotomy provides the optimum operative approach for the localization and microsurgical resection of AVM's that are either obscure or located deep in the brain.     

Frameless stereotaxy with scalp-applied fiducial markers for brain biopsy procedures: experience in 218 cases.

OBJECT: The goal of this study was to develop and assess the use and limitations of performing brain biopsy procedures by using image-guided surgical navigation systems (SNSs; that is, frameless stereotactic systems) with scalp-applied fiducial markers. METHODS: Two hundred eighteen percutaneous brain biopsies were performed in 213 patients by using a frameless stereotactic SNS that operated with either sonic or optical digitizer technology and scalp-applied fiducial markers for the purpose of registering image space with operating room space. Common neurosurgical and stereotactic instrumentation was adapted for use with a localizing wand, and recently developed target and trajectory guidance software was used. Eight (3.7%) of the 218 biopsy specimens were nondiagnostic; five of these (2.4%) were obtained during procedures in 208 supratentorial lesions and three were obtained during procedures in 10 infratentorial lesions (30%; p < 0.001). Complications related to the biopsy procedure occurred in eight patients (seven of whom had supratentorial lesions and one of whom had an infratentorial lesion, p > 0.25). Five complications were intracerebral hemorrhages (two of which required craniotomy), two were infections, and one was wound breakdown after instillation of intratumoral carmustine following biopsy. There were only three cases of sustained morbidity, and there were two deaths and one delayed deterioration due to disease progression. Two surgeons performed the majority of the procedures (193 cases). The three surgeons who performed more than 10 biopsies had complication rates lower than 5%, whereas two of the remaining four surgeons had complication rates greater than 10% (p = 0.15). Twenty-three additional procedures were performed in conjunction with the biopsies: nine brachytherapies; five computer-assisted endoscopies; four cyst aspirations; two instillations of carmustine; two placements of Ommaya reservoirs; and one craniotomy. CONCLUSIONS: Brain biopsy procedures in which guidance is provided by a frameless stereotactic SNS with scalp-applied fiducial markers represents a safe and effective alternative to frame-based stereotactic procedures for supratentorial lesions. There were comparable low rates of morbidity and a high degree of diagnostic success. Strategies for performing posterior fossa biopsies are suggested.     

Complications and diagnostic yield of stereotactic biopsy for the patients with malignant brain tumors

PURPOSE: The purpose of this study was to assess the complication risk rate and diagnostic yield in a series of 211 procedures performed by a consistent method at one institute. MATERIAL AND METHOD: Two hundred and one patients underwent 211 stereotactic biopsy procedures for diagnosis of malignant brain tumor at Niigata University between 1987-2001. Indication for stereotactic biopsy is decided on the following factors: 1) the patient is elderly or unsuitable for craniotomy; 2) the tumor location is in a deep, diffusing, multiple, eloquent site; 3) cytoreductive surgery is not needed to treat the suspected pathology. The specimen was obtained from the target point of CT scan by the aspiration method under local anesthesia except for in six patients who were children or needed operation for a VP shunt under general anesthesia. The lesion was located in 114 cases of cerebral hemisphere, in 44 cases of basal ganglia, in 11 cases of cerebellum and in 11 cases of spreading site. RESULT: Histological diagnosis was obtained in 188 of 211 procedures and the diagnostic yield was 93.5%. There were 104 high grade gliomas, 16 low grade gliomas, 5 germ cell tumors, 37 malignant lymphomas, 19 metastatic tumors and 13 negative/inconclusive biopsies. Sixteen patients incurred complications (7.6%). Four patients (1.6%) suffered intratumoral hemorrhage. Emergency craniotomy was performed in three patients and stereotactic aspiration of hematoma was carried out in one patient. Furthermore, of 12 complications, 9 occurred with the patient showing symptoms of worsening neurological deficit, 2 occurred with general convulsion and 1 occurred with severe facial pain. CONCLUSION: This study provided evidence that stereotactic biopsy was a safe and reliable tool for patients with unresectable malignant brain tumors.     

Stereotactic resection of occult vascular malformations

Angiographically occult vascular malformations can be identified on computerized tomography and magnetic resonance imaging. Surgical excision, when possible, is the treatment of choice in symptomatic lesions. Because these malformations are usually small and can be located in surgically treacherous areas of the brain, stereotactic resection should be considered. Stereotactic resection of a pathologically verified occult vascular malformation was performed in 26 patients in this series (13 females and 13 males, mean age 30 years). Seventeen patients presented with a seizure disorder, four with an intracerebral hemorrhage, and four with a progressive neurological deficit; one patient was asymptomatic. Sixteen patients had normal neurological examinations, nine had neurological signs referable to their lesion, and one had a visual field deficit related to a previous temporal lobectomy. In six patients evidence of acute hemorrhage was found on imaging studies or at surgery, and 11 patients had evidence of previous hemorrhage on imaging studies, determined at surgery or by histological examination. Three patients had evidence of both acute and previous hemorrhage and six patients had no evidence of hemorrhage. Lesions were located in cortical or subcortical areas in 21 patients, in the thalamus or basal ganglia in three, and in the posterior fossa in two. Following stereotactic resection, 24 patients were improved, one patient was unchanged, and one patient was worse. Without stereotaxis or intraoperative ultrasound studies, localization of these lesions at conventional craniotomy can be difficult. A stereotactic craniotomy is ideally suited to the treatment of these benign circumscribed, but potentially devastating lesions.