Retromastoid cisternal Ommaya reservoir for intrathecal therapy of coccidioidomycosis meningitis. Technical note.

A method is described that simplifies placement of an Ommaya reservoir for chronic access to the basilar cisterns. This technique is useful in treating coccidioidomycosis and other fungal meningitides.     

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.     

Modified osteoplastic orbitozygomatic craniotomy. Technical note

The authors report on a surgical technique involving a one-piece osteoplastic bone flap, which incorporates the frontal, temporal, and lateral portions of the orbital rim as a technically simpler alternative to the standard orbitozygomatic (OZ) craniotomy. The orbital rim component extends just laterally from the supraorbital foramen/notch to the frontozygomatic suture. This craniotomy obviates the need for removing the zygoma and has evolved from the authors' experience in more than 200 patients with a variety of pathological lesions, both vascular and tumorous. The osteoplastic aspect of this technique was initially evaluated in 14 cadaveric sites in seven heads dissected prior to implementing this procedure clinically. The osteoplastic bone flap minimally obstructs the surgical view and provides all the advantages of a standard OZ craniotomy. Temporalis muscle atrophy leading to temporal hollowing is avoided, a bone union to the calvaria is improved, and the possibility of bone infection is decreased. The osteoplastic component of the technique adds to the improved long-term cosmesis and warrants active consideration in the art of neurosurgery.     

Image-guided frameless stereotactic biopsy sampling of parasellar lesions. Technical note

Interactive image-guided neuronavigation was used to obtain biopsy specimens of cavernous sinus (CS) tumors via the foramen ovale. In this study the authors demonstrated a minimally invasive approach in the management of these lesions. In four patients, whose ages ranged from 29 to 89 years (mean 61.2 years) and who harbored undefined lesions invading the CS, neuronavigation was used to perform frameless stereotactic fine-needle biopsy sampling through the foramen ovale. The biopsy site was confirmed on postoperative computerized tomography scanning. The frameless technique was accurate in displaying a real-time trajectory of the biopsy needle throughout the procedure. The lesions within the CS were approached precisely and safely. Diagnostic tissue was obtained in all cases and treatment was administered with the aid of stereotactic radiosurgery or fractionated stereotactic radiotherapy. The patients were discharged after an overnight stay with no complications. Neuronavigation is a precise and useful tool for image-guided biopsy sampling of CS tumors via the foramen ovale.     

Initial experience related to the use of the Cosman-Roberts-Wells stereotactic instrument. Technical note

Initial experience with a new arc-radius design of stereotactic frame that interfaced with the existing components of the Brown-Roberts-Wells instrument is reported. Over a 6-month period, 32 procedures were performed on 23 males and nine female patients (mean age 32 years); these included 27 stereotactic biopsy procedures, two stereotactic implantations of cyst catheter reservoirs, two ventriculoscopic aspirations of third ventricular colloid cysts, and one stereotactic aspiration of a craniopharyngioma. In all cases successful targeting was achieved and verified by postoperative computerized tomography. There were no operation-related complications. This new frame offers rapid and accurate targeting and is a useful adjunct to the stereotactic armamentarium.     

Double-headed stereotaxic carrier apparatus for insertion of depth electrodes. Technical note

A carrier device has been developed for use with a sterotaxic apparatus. It can be attached to the OBT frame or to any Leksell-type frame. With this carrier, intracranial insertion of commercially available depth electrodes with built-in connectors is possible. By using two different heads mounted on a single carrier, the surgeon can perform a transcutaneous twist-drill trephination and attach the screws through a chuck, adjust the device in the horizontal plane, and then insert and anchor the electrodes by using a small platform with a hinged roof.     

Computed tomography guided stereotactic thalamotomy using the Brown-Roberts-Wells system for nonparkinsonian movement disorders. Technical note.

A technique is described for stereotactic thalamotomy, using the Brown-Roberts-Wells (BRW) system and computed tomography (CT) without the need for ventriculography. Previous reports have suggested that the BRW system lacks sufficient accuracy (compared with ventriculography) for CT-directed functional neurosurgery. However, using this method, our findings demonstrate excellent clinical accuracy and safety in 12 consecutive patients with nonparkinsonian movement disorders.     

Percutaneous insertion of peritoneal shunt catheters with use of the Veress needle. Technical note

A safe percutaneous method of insertion of peritoneal shunt catheters is described. The method is based on the use of the Veress needle.     

Hemiparkinsonism as a complication of an Ommaya reservoir. Case report

The authors describe the case of a 28-year-old woman who developed the following symptoms in her right hand: a lasting resting tremor, transient focal rigidity, and paresthesia. These deficits occurred following treatment with intrathecal methotrexate via an Ommaya reservoir which was placed too deeply, resulting in trauma to the contralateral mesencephalon.     

Modified coronal computerized tomographic cuts for transsphenoidal surgery. Technical note

Computerized tomographic (CT) cuts passing through the anterior nasal spine and the most prominent part of the sellar floor (spino-sellar or SS cuts) were found to be use-ful in minimizing the chances of anatomical disorientation during the transsphenoidal microsurgical approach as well as in preoperative planning and selection of the length and choice of the instruments to be used. Routine preoperative SS cuts of CT scan are advised.     

Navigation-guided Ommaya reservoir placement: implications for the treatment of leptomeningeal metastases.

Ommaya reservoirs are commonly used in the diagnosis and management of leptomeningeal metastases (LM) from malignant tumors. The present study investigates the utility of an intraoperative navigation-guided technique for Ommaya reservoir placement. Between March 2004 and December 2005, 85 navigation-guided Ommaya reservoir placements were performed in 77 patients with intracranial malignancies at the Komagome Metropolitan Hospital. Anterior horn puncture and posterior horn puncture were used for 59 and 26 procedures, respectively. A slit ventricle was present in 6 cases. All procedures were performed under assistance from the Medtronic STEALTH STATION TRIA navigation system. Computed tomographic (CT) scans were routinely obtained just after completion of the procedure. Patients diagnosed with LM received subsequent treatment. An Ommaya catheter was applied to the ventricular puncture needle registered in the navigation system and was inserted into the lateral ventricle. Using the real-time "Guidance View", the surgeon was able to verify the catheter position continuously during the procedure. Postoperative CT scan revealed an appropriate catheter position in all except for one case. Complications (catheter malposition) occurred in only one case (complication rate, 1.2%). None of the patients experienced hemorrhage or infection. In conclusion, navigation-guided Ommaya reservoir placement was associated with a very low incidence of complications. This method appears to be safe and effective when employed in patients with intracranial malignancy.     

A contralateral, transfrontal, extraventricular approach to stereotactic brainstem biopsy procedures. Technical note

The authors report on the technique and results of stereotactic biopsy for intrinsic lateral pontine and medial cerebellar lesions via a contralateral, transfrontal, extraventricular approach. Multiplanar stereotactic magnetic resonance imaging was used to plan an intraparenchymal approach, thus limiting the number of crossed pial surfaces to one and eliminating the need to cross ependymal surfaces. After the administration of a local anesthetic agent with light intravenous sedation, six patients harboring intrinsic lateral pontine lesions underwent biopsies via this intraparenchymal approach with 100% diagnostic yield and no operative morbidity. In comparison to the ipsilateral transfrontal approach, the contralateral approach laterally expands the infratentorial area accessible during biopsy to include the lateral pons and middle cerebellar peduncle. The contralateral, transfrontal, extraventricular approach is a useful, straightforward and safe alternative to the suboccipital transcerebellar and ipsilateral, transfrontal, transtentorial routes for reaching lesions of the lateral pons and middle cerebellar peduncle.     

Stereotatic implantation of Ommaya reservoir in the management of brain abscesses

We evaluated the effectiveness of computed tomography (CT)-guided stereotatic implantation of Ommaya reservoir in the management of brain abscess. Forty-five patients with brain abscesses were treated with CT-guided stereotatic implantation of Ommaya reservoir and followed up between September 1998 and February 2008. The Glasgow Outcome Scale (GOS) was use to evaluate the effectiveness of the Ommaya Reservoir treatment. The GOS score at 3-months post-operation was 5 for 41 patients (91.1%), 4 for 2 patients (4.4%) and 3 for 2 patients (4.4%), respectively. The results suggest that the CT-guided stereotatic implantation of Ommaya reservoir is a potential technique that can be safely used to treat the brain abscess.     

CT-guided stereotaxic implantation of the Ommaya reservoir for cystic brain tumors

We report the use of CT-guided stereotaxic system to implant Ommaya reservoir in 26 patients with cystic brain tumors consisting of 16 gliomas, 3 craniopharyngiomas, 3 metastatic brain tumors and 5 other and unknown pathologies, on the way of their biopsy. The entire procedure was carried out in the CT room using Leksell's CT stereotaxic system. In 24 cases with supratentorial tumors, it was at the option of the operator to take any approach such as frontal, posterior temporal and parietal approaches. Especially in 3 cases of craniopharyngioma, we inserted the tube into their cyst directly so that the ventricle should not be open to the cyst. Also in cases of a pontine glioma and a C-P angle metastatic tumor, we used retromastoid approach to the posterior fossa by making patient's heads turned about 30 to 40 degrees to contralateral side of the approach, with slight flexion of the neck. Minimal bleeding occurred during operation in one case, however, it showed no clinical symptoms. Advantages of this method are as follows: Operative invasion is minimal; The surgeon can check the course of the cannula and position of the tip of Ommaya tube even at operation, and can modify it, if necessary.     

Sagittal synostectomy. Technical note.

A procedure for correction of scaphocephaly is described. It differs from strip craniectomy in that it provides early correction of the deformity by removing the protuberances at the bregma and at the occiput. The morbidity and mortality of this procedure is no greater than with the more standard linear craniectomy.