Preliminary experience with the Berger neurobiopsy device for ultrasound guided aspiration and biopsy of intracranial lesions

Safety and Accuracy of Ultrasound-guided Burr Hole Brain Abscess Aspiration

BACKGROUND

 Ultrasound-guided burr hole biopsies or catheter placements are quick and safe procedures. The use of these procedures for treatment of brain abscesses has been reported, but larger series are missing. The aim of our study was to evaluate the accuracy and safety of the methods.

PATIENTS

 Twenty-five brain abscess aspirations in 17 patients were analyzed. Fourteen procedures were performed to evacuate abscesses in eloquent regions; another 3 were located deeply in the cerebellar hemispheres.

RESULTS

 In all the procedures, a histopathologic diagnosis could be established. Only one transient deterioration of a hemiparesis occurred; other operative complications were not observed. Six patients needed more than one operation due to a relapse of the abscess. Two out of three cerebellar abscesses could be cured with one aspiration. Thirteen patients had an excellent outcome, and 2 remained severely disabled. One patient died from cerebritis and another from a neoplasm. In every procedure, a proper visualization of the abscess and monitoring of the penetration and aspiration could easily be performed.

CONCLUSION

 Ultrasound-guided burr hole aspiration is minimally invasive, quick, and has a very low complication rate. It offers the advantage to adapt to intraoperatively changing anatomy. The rate of recurrence is not lower than in other treatment modalities.

Real-time ultrasound monitoring during intracranial needle biopsies: operative results and detection of complications in 100 cases

OBJECTIVE

Intraoperative ultrasound displays dynamic processes intraoperatively. Performing burr-hole biopsies under a real-time visual control is an interesting option for the neurosurgeon. However, the percentage of conclusive diagnoses obtained by this technique and the rate of complications must be evaluated in a larger series.

METHODS

One hundred consecutive intracranial biopsies were analyzed. Through a burr hole, the lesion was localized by ultrasonography, and the planned needle trajectory was superimposed onto the image. Intracranial vessels were imaged by Doppler flow signals. Biopsies were taken in a mean depth of 41 mm (maximal 65 mm) from different parts of each tumor.

RESULTS

Thirty-six lesions involved the corpus callosum, 16 lesions were located deeply within the white matter, five in the internal capsule, and one in the upper brainstem. There were three cerebellar and 17 temporal lesions. Ten tumors did not exceed a diameter of 15 mm in any plane. The mean time interval from skin incision to the end of suturing was 45 minutes, and the mean time from the surgeons entering the operating theater to leaving the theater was 63 minutes. In 95% of the lesions, a diagnosis could be established. Transient neurologic deficits occurred in five patients, which were permanent in three. In 42 patients without postoperative neurological symptoms, postoperative computed tomography scans were obtained within 24 hours; a visible hemorrhage occurred in eight (19%), six of which were seen intraoperatively.

CONCLUSION

When intraoperative ultrasound-navigated biopsies were used they obtained a similar percentage of conclusive diagnoses as stereotactic biopsies. The complication rate is comparable as well. Emerging intracranial complications such as hemorrhages can be observed. However, their incidence cannot be decreased.

Real-time 3D-surface-guided head refixation useful for fractionated stereotactic radiotherapy

Accurate and precise head refixation in fractionated stereotactic radiotherapy has been achieved through alignment of real-time 3D-surface images with a reference surface image. The reference surface image is either a 3D optical surface image taken at simulation with the desired treatment position, or a CT/MRI-surface rendering in the treatment plan with corrections for patient motion during CT/MRI scans and partial volume effects. The real-time 3D surface images are rapidly captured by using a 3D video camera mounted on the ceiling of the treatment vault. Any facial expression such as mouth opening that affects surface shape and location can be avoided using a new facial monitoring technique. The image artifacts on the real-time surface can generally be removed by setting a threshold of jumps at the neighboring points while preserving detailed features of the surface of interest. Such a real-time surface image, registered in the treatment machine coordinate system, provides a reliable representation of the patient head position during the treatment. A fast automatic alignment between the real-time surface and the reference surface using a modified iterative-closest-point method leads to an efficient and robust surface-guided target refixation. Experimental and clinical results demonstrate the excellent efficacy of <2 min set-up time, the desired accuracy and precision of <1 mm in isocenter shifts, and <1 degree in rotation.

Stereotactic management of bacterial brain abscesses

BACKGROUND

CT and MR guided stereotactic techniques have provided promising results in the management of brain abscesses. We reviewed our results of stereotactic management of brain abscesses in 20 consecutive patients with 28 abscesses from 1986 to 1993.

METHODS

13 abscesses were in the cerebral hemispheres, 12 in the cerebellum, 2 in the pons and 1 in the thalamus. The bacterial organism was isolated in 12 of the 20 cases. All patients, except one who had a tuberculous abscess, were on antibiotics for less than 7 weeks.

RESULTS

Although there were 3 patients in coma before surgery, the mortality rate was zero and 17 patients had an excellent recovery with 3 patients having a persistent mild neurologic disability. Stereotactic aspiration of the largest lesion in the patients with multiple brain abscesses combined with intravenous antibiotic therapy was sufficient for the resolution of all lesions. Two of our patients treated with antibiotics alone showed abscess progression with neurologic worsening.

CONCLUSION

Stereotactic aspiration is safe, accurate, and when combined with the appropriate antibiotics, should be considered the procedure of choice in the management of brain abscesses.

Frameless stereotactic drainage of intracranial abscesses

Our preliminary experience is presented in the use of the Aachen Computer-Assisted Surgery device for frameless stereotactic puncture and drainage of intracranial abscesses through a 2.1-mm twist-drill hole. The apparatus and technique are described, along with the results of its use in 2 patients. Intraoperatively the semiactive system presents a schematic display of the drainage probe projected into a 3D model of the situs on the monitor screen corresponding to the instrument's position. As the surgeon directs the probe into the abscess the corresponding section is displayed. Thereby drainage is easily achieved under visual control.