- 1. Image guidance in Neurosurgery Towards improved quality and
consistency in patient care Deepak Agrawal Assist Prof, Department
of Neurosurgery All India Institute of Medical Sciences, New
Delhi
2. NEURONAVIGATION (IG SURGERY)
- A step towards consistency in surgical results
- Improves the quality of neurosurgical output in a centre
- Increases accuracy of the procedure
3. OBSTACLES
- High initial purchase cost
- Cost of disposables (fiducials)
4. INITIAL PURCHASE COSTS
- Initial systems cost upto US$ 500000
- AIIMS was the first centre in India to have IG system
(Stealthstation) in India in 1998
5. MANTAINANCE COSTS
- Can be nearly 10% of capital cost every yr
- Nowadays maintenance contracts 5-10 yrs built into the initial
purchase cost
6. LEARNING CURVE
- Initially added 2-3hrs to the operating time
- Systems are getting more user friendly
- With experience, only 15-20 minutes are needed to set up the
system
7. COST OF DISPOSABLES
- Set of 10 fiducials costs $100
8. AIMS & OBJECTIVES
- To assess Vitamin E capsules as fiducials for IG
neurosurgery
- Compare the accuracy of registration of Vitamin E capsules and
proprietary fiducials
9. Materials & Methods
- Overall accuracy of registration (OAR) in mm (automatically
calculated by stealthstation)
- OAR compared for Vitamin E & proprietary fiducials
10. Materials & Methods
- Accuracy physically checked by touching known bony points
11. 12. VITAMIN E CAPSULES
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- Dab area with Tinc Benzoin
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- Tape the capsule with leukoplast/ dynapore
13. 14. VITAMIN E CAPSULES 15. MPRAGE 16. 17. FLAIR T2 FATSAT
18. OBSERVATIONS
- Vitamin E group-23 pts over 6 months
- Regular fiducials group-22 historical controls over 6 months
prior to introduction of vitamin E
19. RESULTS (Overall Accuracy of registration {OAR})
- Mean OAR- 1.84 mm (1.2- 2.8 mm)
- Regular Fiducials- 22 pts
- Mean OAR- 2.41 mm (2.1-2.9 mm).
20.
- In spite of availability of image guidance (neuronavigation) at
major centers around the world, most trans-sphenoidal surgeries for
pituitary adenomas continue to be done under fluoroscopic
control.
21. FLOUROSCOPY (Image intensifier)
- Inability to confirm midline access to sella
- Relationship of critical structures like carotid artery is not
known
- Lead aprons- surgeon fatigue
Image Guidance in Trans-sphenoidal surgery 22. IMAGE
GUIDANCE
- Exquisite 3D visualization of midline & carotid
arteries
- Not affected by brain shift
- Almost real time guidance
- None of the disadv of fluoroscopy
Image Guidance in Trans-sphenoidal surgery 23. 24. AIMS &
OBJECTIVES
- To study the utility of image guidance in trans-sphenoidal
surgeries for pituitary adenomas in a tertiary care teaching
hospital
Image Guidance in Trans-sphenoidal surgery 25. MATERIALS &
METHODS
- Prospective study carried out over a 5 month period
- All surgeries were done under image-guidance only & no
fluoroscopy was employed.
Image Guidance in Trans-sphenoidal surgery 26. MATERIALS &
METHODS
- Overall accuracy of registration (OAR)
- Visualization of carotid arteries
- intra-operative complications
Image Guidance in Trans-sphenoidal surgery 27. MATERIALS &
METHODS
- All patients had a contrast CT of the head done within 48 hours
of surgery to see for residual tumor.
Image Guidance in Trans-sphenoidal surgery 28. TECHNIQUE Image
Guidance in Trans-sphenoidal surgery 29. TECHNIQUE 30. TECHNIQUE
Image Guidance in Trans-sphenoidal surgery 31. TECHNIQUE Image
Guidance in Trans-sphenoidal surgery 32. TECHNIQUE Image Guidance
in Trans-sphenoidal surgery 33. TECHNIQUE 34. TECHNIQUE Image
Guidance in Trans-sphenoidal surgery 35. OBSERVATIONS
- Seven pts underwent IG pit ad surgery
- Three patients had giant Pit ad
- Two had recurrent/residual disease
Image Guidance in Trans-sphenoidal surgery 36. OBSERVATIONS
- 3 patients (all giant tumors) non-contrast MR images were used
in for image guidance and contrast CT images were used in the
rest
Image Guidance in Trans-sphenoidal surgery 37. RESULTS
- mean set up time for image-guidance was 12 minutes (range 7-17
minutes)
- mean overall accuracy of registration was 1.6 mm (range 1.4-2.1
mm)
- mean operating time was 68 minutes (range 47-84 minutes)
Image Guidance in Trans-sphenoidal surgery 38. RESULTS
- In all cases the midline and the relation of the carotid artery
to the sella could be confirmed using IG
- IG greatly helped in increasing the bony opening laterally
Image Guidance in Trans-sphenoidal surgery 39. RESULTS
- No intra-operative or post-operative complications in any of
the patients.
Image Guidance in Trans-sphenoidal surgery 40. RESULTS
- Complete (grade 1) removal -3 pts.
Image Guidance in Trans-sphenoidal surgery 41. 42. SPECIAL
ADVANTAGES
- Recurrent/Residual tumors
- All trans-sphenoidal procedures
43. CONCLUSIONS
- Image guidance markedly improves the visualization of sellar
floor and its relation to the carotid arteries
- Improves the safety and quality of the surgical procedure
- Free of limitations of fluoroscopy
Image Guidance in Trans-sphenoidal surgery 44. CONCLUSIONS
- Vitamin E capsules serve as excellent fiducials for image
guided neurosurgery
- Save more than 99% costs on the disposables
- Improve accuracy of the procedure as scalp movement is
diminished
45. THANK YOU
- For want of a nail the shoe was lost,For want of a shoe the
horse was lost,For want of a horse the rider was lost,For want of a
rider the battle was lost,For want of a battle the Kingdom was
lost,And all for the want of a horseshoe nail.