This document discusses various gadgets used in neurosurgery including neuronavigation systems. Neuronavigation uses preoperative images like CT and MRI to provide navigation during surgery. It helps localize lesions, perform biopsies and resections, and avoid damaging eloquent areas. Accuracy is typically around 2mm. While helpful, it can be time-consuming and restrict head movement. Future developments may involve microsurgical robots to compensate for brain shift. Fluorescence imaging using agents like 5-ALA and sodium fluorescein can also help identify tumor margins during surgery but have limitations. Overall, neuronavigation and fluorescence are useful adjuncts but experience and anatomy knowledge remain important.

1. GADGETS IN NEUROSURGERY
DR.K.VAMSHIKRISHNA
CONSULTANTNEUROSURGEON
CAREHOSPITALS
HYDERABAD

2. NEURO NAVIGATION
STEREOTACTIC FRAME
NERVE MONITOR
O ARM
MICROSCOPE
INTRA OP MRI
DOPPLER PERFUSION
ICP MONITOR
LASER
FLEXIBLE ENDOSCOPE
INTER LAMINAR ENDOSCOPE

3. NEURONAVIGATION
How to reach the lesion
GPS

4. 1. Where are the lesions
or the functional area
situated inside the skull?
2. How can this be found
during surgical
procedure?
The answer to the first
question was possible
due to the development
of modern neuroimagistic
techniques (CT, MRI).
The answer to the second
question is more complex
and had a longer
evolution.

6. • Intraoperative localization technique
• Including craniotomy position was based on
knowledge of specific bone landmarks from the
skull, as coronal suture, external occipital
protuberance, pterion, etc EVION CAPSULE
• Neurosurgeon’s ability and experience to perform
a 3D orientation .

7. • This ANATOMIC localization method WAS and IS still considered the
GOLDEN STANDARD both before and after CT/MRI era.

8. •No one can deny the importance of
Neuronavigational facilities which
became a cornerstone in most of the
Advanced Neurosurgical theatres
worldwide.

15. Clinical applications IN
SURGERY
• LOCALIZATION OF SMALL INTRACRANIAL
LESIONS
• SKULL-BASE SURGERY
• INTRA CEREBRAL BIOPSIES
• INTRACRANIAL ENDOSCOPY
• FUNCTIONAL NEUROSURGERY
• SPINAL NAVIGATION
• TRAUMA

16. How does it help
• It provides orientation to the surgeon with sufficient application accuracy
• Precise planning of the craniotomy
• Can target small, subcortical lesions
• Define the tumour margins and the limits of resection
• In skull base lesions, it was useful in localizing encased and displaced
vascular structures, the tumor extension into various brain crevices and the
position of osseous landmarks

17. • ROLE IN EPILEPSY SURGERY IN PREDICTING THE LENGTH OF
THE CORPUS CALLOSUM DIVISION IN CORPUS CALLOSECTOMY,
IN JUDGING THE POSTERIOR MARGIN OF THE ANTERIOR
TEMPORAL RESECTION AND IN LOCALIZING THE HIPPOCAMPUS
• ENDOSCOPIC SURGERY, WHERE AN ORIENTATION WITHIN THE
VENTRICULAR SYSTEM WAS PROVIDED

18. • An error in the white matter by the navigation device even in the range of 3 mm or 4 mm is still
lower than when relying only on neurosurgical knowledge
• The neurosurgeon is able to calculate the localization and approach a small lesion accurately,
therefore feeling more confident
• The corticotomy is associated with less .Incorporation of diffusion tensor imaging (DTI) and fiber
tracking into the image data set also helps the precision of the system and prevents damage to the
eloquent areas
• Visualization of certain low-grade tumors may be enhanced by fusing color-encoded fluid-
attenuated inversion recovery (FLAIR) images with high-resolution volume MRI. PET, cerebral blood
volume or MRS maps may be fused with a stereotactic study to identify the optimal point for brain
biopsy .
• Navigation system also reduces the length of surgery, lowers the incidence of wound infections, and
shortens length of hospital stay .

19. STEPS

20. • STEPS OF NAVIGATION

21. • OBTAINING PREOPERATIVE
IMAGES
• REGISTRATION
• INTRAOPERATIVE LOCALIZATION
• INTRAOPERATIVE CONTROL
• OBTAINING INTRAOPERATIVE
IMAGES AND FUSION WITH
PREOPERATIVE ONES
• VISUALIZATION AND SURGERY.

25. Basic principles of navigated surgery are to see the tip of
a pointer in an image space. A relationship between the
device space and the image space has to be established.
Today's navigation systems provide approximately 2mm
accuracy

40. DISADVANTAGES
• Probe of the stealth station is bulky restricting its manipulation under the microscope and its introduction into
narrow operative fields e.G. The cerebellopontine angle or the petrous bone.
• The view of the surgeon must change from the microscope to the workstation console, while localizing an
anatomical structure with its probe which may inadvertently cause neurological trauma.
• The patient’s head cannot be moved to gain a more optimal operating position as that would lead to loss of
registration
• Time consuming
• Calculation and registration,
• Restriction of space and view inside the operating field

41. •AT THE END OF THE DAY QUESTION IS DO WE
NEED IT OR CANT WE DO IT WITH OUT IT

42. Future
• It is difficult to provide any prognosis for the development and role of navigated surgery in the
future, as the computer technology is changing so rapidly
• A presumable future of navigation seems to depend on microsurgical robots
• There are some ideas about combining these two innovations to solve the most important
shortcoming of neuronavigation : brain shift.
• This important can be achieved by injecting microsurgical robots through the vessels and
synchronizing registration while observing the brain through various aspects from different points.
• By this root, signals can be transferred to a central computer out of the body. By integrating this
information, a 3D map of different points of the brain and its pathologies can be formed.
Simultaneously, these robots can play some therapeutic roles

45. CONCLUSIONS
• Progressive advances in technology will improve the cost-benefit ratio and the user-
friendliness of the system and in the near future it may help to realize the aim of complete
cytoreductive surgery with minimal morbidity

47. The primary fluorescence agent that has been
studied in glioma is 5-aminolevulinic acid.
This produces fluorescent porphyrins that
accumulate in glioma cells, resulting in fluorescence
under blue light.

48. LIMITATIONS
• Cost
• Need to switch between blue light (for identification of fluorescent tissue) and white
light (to delineate the anatomy of the nonfluorescent tissue and vessels for
coagulation) frequently during surgery
• Photosensitivity of the 5-ALA compound

49. Tumor Fluorescence
The use of intraoperative 5-aminolevulinic acid fluorescence
has been shown to increase the extent of resection in high-
grade glioma surgery.
Sodium fluorescein is an alternate fluorescence agent with
advantages of low cost, low adverse effect profile, and ability
to visualize anatomical detail under the fluorescence filter

50. • Intravenous sodium fluorescein administration results in green fluorescence under
yellow light in areas of blood–brain barrier impairment due to the accumulation of
sodium fluorescein in the extracellular space.
• The primary criticism regarding the use of sodium fluorescein pertains to the fact
that fluorescence is not tumor cell specific – there is a potential for false-positive
fluorescence garnered by accumulation in areas of perilesional edema and
surgical tissue injury.

54. FUTURE

57. OUR NAVIGATION TEAM RADIOLOGY