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

Learning curve

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

Propriety item.

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

INTERNAL VALIDATION

Overall accuracy of registration (OAR) in mm (automatically calculated by stealthstation)

OAR compared for Vitamin E & proprietary fiducials

10. Materials & Methods

External Validation

Accuracy physically checked by touching known bony points

11. 12. VITAMIN E CAPSULES

Easily available

Extremely cheap

Easy to apply

• • Dab area with Tinc Benzoin

• • Tape the capsule with leukoplast/ dynapore

Easy to register

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})

Vitamin E- 23 pts

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)

Limitations

Radiation exposure

Only 2D images available

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

ADVANTAGES

Exquisite 3D visualization of midline & carotid arteries

Not affected by brain shift

Almost real time guidance

None of the disadv of fluoroscopy

Frees up X-ray machine

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

Parameters Assessed

Time to set up IG in OR

Overall accuracy of registration (OAR)

Midline access

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

Postoperative scans

Complete (grade 1) removal -3 pts.

Residual tumor -4 pts.

Image Guidance in Trans-sphenoidal surgery 41. 42. SPECIAL ADVANTAGES

Recurrent/Residual tumors

Fibrous Tumors

All trans-sphenoidal procedures

Residency Programs

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.