The Centre of Image Guided Innovation and

Therapeutic Intervention (CIGITI)

The Hospital for Sick Children

University of Toronto, Canada

A Physical Brain Model for Neuroendoscopic Training, Evaluation,

and Robot Design

James M. Drake FRCSC

11th SANS & 2nd APNS Annual Meeting Joint Conference Riyadh April 2017

Surgical Simulation for Training• Surgical simulation increasing (mandatory) role in training: fail

safe environment, repetitive training/evaluation/certification

• Number of unanswered important issues: fidelity (realism), translation to real world

• ETV ideal task – technically challenging, high risk, difficult to verbally teach, hand over

• Endoscopic colloid cyst resection, ETV-CPC, Endoscopic craniosynostosis surgery similar technical challenges

• Number of simulators, virtual, physical, cadaver – which is best ?

J Neurosurg. 2013 Feb;118(2):250-7. Needs assessment for simulation training in neuroendoscopy: a Canadian national survey. Haji FA1, Dubrowski A, Drake J, de Ribaupierre S. RESULTS: Thirty-two (55.2%) of 58 surgeons completed the survey. All believed that virtual reality simulation training for ETV would be a valuable addition to clinical training. Selection of ventriculostomy site, navigation within the ventricles, and performance of the ventriculostomyranked as the most important steps to simulate. Technically inadequate ventriculostomy and inappropriate fenestration site selection were ranked as the most frequent/significant errors. A standard ETV module was thought to be most beneficial for resident training.

New anatomical simulator for pediatric neuroendoscopicpractice. Coelho G, Zymberg S, Lyra M, Zanon N, Warf B. Childs Nerv Syst. 2015 Feb;31(2):213-9

Quality assessment of a new surgical simulator for neuroendoscopic training. FilhoFV, Coelho G, Cavalheiro S, Lyra M, ZymbergST. Neurosurg Focus. 2011 Apr;30(4):E17.

Anatomical pediatric model for craniosynostosissurgical training. Coelho G, Warf B, Lyra M, ZanonN. Childs Nerv Syst. 2014 Dec;30(12):2009-14

J Neurosurg. 2014 Aug;121(2):228-46. doi: 10.3171/2014.5.JNS131766. Epub 2014 Jun 20.

The use of simulation in neurosurgical education and training. A systematic review.Kirkman MA1, Ahmed M, Albert AF, Wilson MH, Nandi D, Sevdalis N.

RESULTS:Twenty-eight articles formed the basis of this systematic review. Several different simulators are at the neurosurgeon's disposal, including those for ventriculostomy, neuroendoscopic procedures, and spinal surgery, with evidence for improved performance in a range of procedures. Feedback from participants has generally been favorable. However, study quality was found to be poor overall, with many studies hampered by nonrandomized design, presenting normal rather than abnormal anatomy, lack of control groups and long-term follow-up, poor study reporting, lack of evidence of improved simulator performance translating into clinical benefit, and poor reliability and validity evidence. The mean Medical Education Research Study Quality Instrument score of included studies was 9.21 ± 1.95 (± SD) out of a possible score of 18.CONCLUSIONS:The authors demonstrate qualitative and quantitative benefits of a range of neurosurgical simulators but find significant shortfalls in methodology and design. Future studies should seek to improve study design and reporting, and provide long-term follow-up data on simulated and ideally patient outcomes.

Model Based Pediatric Neurosendoscopy Courses

Image Guided Colloid Cyst ResectionFlexible scope ETV CPC

Metopic Endoscopic Craniosynostosis Virtual Reality ETV

Construction of the Simulator

Mold with ventricular cast Choroid Plexus, venous detail Brain with encasing skull

Replaceable III vent floor III vent floor installed Brain stem with basilar system

Stronglydisagree

(1)

Disagree

(2)

Neutral

(3)

Agree

(4)

Stronglyagree

(5)

1. The camera view is comparable to what you wouldsee in a real surgical scene.

1 (4 %) 14 (61 %) 8 (35 %)

2. Performing the ventriculostomy on the floor of the 3rd ventricle of the model feels like it does in reality

1 (4 %) 16 (64 %) 8 (32 %)

3. The simulator matches actual tissue propertiesclosely.

1 (4 %) 19 (76 %) 5 (20 %)

4. The bleeding looks realistic. 12 (48 %) 13 (52 %)

5. This model helps to develop camera skills needed forETV.

7 (29 %) 17 (71 %)

6. This model helps to develop hand-eye coordinationneeded for ETV.

8 (32 %) 17 (68 %)

7. The ventriculostomy task is a valuable training exercise.

5 (20 %) 20 (80 %)

8. Use of this model will increase resident competencywhen used to train residents prior to their first ETV.

5 (20 %) 20 (80 %)

9. I would be interested in using this model to train residents.

6 (24 %) 19 (76 %)

42 itemsDevelopment and content validation of performance assessments for endoscopic third ventriculostomy. Breimer GE, Haji FA, Hoving EW, Drake JM. Childs Nerv Syst. 2015 Aug;31(8):1247-59.

Global Rating Score – 9 items

Testing reliability and validity of the Neuro-Endoscopic Ventriculostomy Assessment Tool (NEVAT) Gerben E. Breimer,, Faizal A. Haji, Giuseppe Cinalli MD, Eelco W. Hoving, James M. Drake, Neurosurgery in Press

Virtual Reality Simulator

Q u e s t i o n n a i r e

Recruitment and group assignment (n = 26)

Groups 1+ 2: Physical

Simulator ETV Trial (n = 13)

Groups 3 +4: VR Simulator ETV Trial (n = 13)

Groups 1+ 2: VR Simulator

ETV Trial (n = 13)

Groups 3 +4: Physical Simulator ETV Trial (n = 13)

Q u e s t i o n n a i r e

Domain Physical simulator

mean rating (SD)

VR simulator mean

rating (SD)

p-value

Anatomy

Surface 3.9 (0.7) 3.8 (0.9) 0.50

Lateral ventricle 4.1 (0.6) 4.5 (0.7) 0.04

Third ventricular floor 4.0 (0.9) 4.4 (0.6) 0.03

Overall 4.0 (0.6) 4.2 (0.6) 0.11

Domain Physical simulator

mean rating (SD)

VR simulator mean

rating (SD)

p-value

Instrument Handling

Endoscope 4.7 (0.6) 4.0 (0.9) <0.01

Tools 4.6 (0.6) 3.9 (0.6) <0.01

Tactile feedback 4.4 (0.7) 3.4 (1.2) <0.01

Tissue manipulation 4.3 (0.7) 3.6 (1.1) 0.02

Overall 4.5 (0.5) 3.7 (0.8) <0.01

Content of procedure

Steps 4.4 (0.6) 4.2 (0.9) 0.07

Skills 4.4 (0.6) 4.0 (0.9) 0.04

Challenge 3.8 (1.0) 3.4 (1.1) 0.11

Overall 4.2 (0.6) 3.9 (0.8) 0.03

Domain Physical simulator

mean rating (SD)

VR simulator mean

rating (SD)

p-value

Overall fidelity (realism)

Suspended disbelief 3.9 (0.6) 3.8 (0.7) 0.23

Real-life comparability 4.1 (0.6) 3.9 (0.7) 0.75

Real-life situations,

factors, and variables

in scenario

4.0 (0.7) 3.8 (0.9) 0.26

Overall 4.0 (0.5) 3.8 (0.6) 0.31

Domain SickKids simulator NeuroTouch

Cost (USD) $6,000* $80,000

Durability Must replace 3rd ventricle floor

w/ each case and silicone brain

w/multiple uses

Can be used repeatedly

without any additional

cost/materials

Variability of

clinical

cases

New cases require new brain

mold/floor insert; bleeding

scenarios available; can be

used with neuronavigation

Only one case currently

available, additional cases

require re-segmentation of

underlying scenario

*Estimate does not include cost of neuroendoscopic equipment

Design and Evaluation of a Concentric Tube Robot for Minimally-Invasive Endoscopic Pediatric NeurosurgeryV. Bodani, H. Azimian, T. Looi, J.M. Drake

Development of a Patient-Specific Brain Simulator for Endoscopic

Colloid Cyst ResectionVivek Bodani, Gerben Breimer, Faizal Haji, Thomas Looi, James Drake

Center for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children

41st Annual William S. Keith Professorship in NeurosurgeryJune 6, 2016

Colloid Cysts of the Third Ventricle

• 0.5 – 2% of all intracranial tumors1

• Acute non-communicating hydrocephalus, sudden death, headache, memory disturbance

• Microsurgical approach –transcortical, transcallosal– “Gold standard”

• Endoscopic approach– Reduced morbidity– Limited access to and visualization of

the site of cyst attachment to the roof of third ventricle

– Increased rate of subtotal resection, cyst recurrence, reoperation2

Chowdhry et al. 20133

Patel et al. 20124

Simulation-Based Medical Education

• Obtaining the required operative experience can be difficult5:– Work hour restrictions– Increased complexity of procedures– Rapidly advancing technology– Increased demand for patient safety,

cost-efficiency

• Simulators provide a risk-free environment without time or resource constraints6–9

• Research Objectives:– Design and construct a patient-specific

silicone-based brain simulator for endoscopic colloid cyst resection

– Evaluate the simulator’s realism (face validity) and procedural/educational content (content validity)

BrightMatter Brain Simulator10

NeuroTouch5

Design Requirements

• Highly realistic

– Appearance• Patient-specific anatomy

• Bleeding

• Realistic sulcal/gyral patterns

– Tissue properties and tactile feedback

– Use of actual endoscopic instruments

– Neuronavigation: CT, MRI

• Inexpensive

• Reusable

• Easy storage/maintenance

• Simple to fabricate

Preoperative Imaging Segmentation

3D Modeling

3D Printing and Silicone Molding

Fused Deposition Modeling

Replicator 2(Makerbot Industries, New York City, NY, USA)

Lulzbot Taz5(Aleph Objects, Inc., Loveland, CO, USA)

ColorJet Printing

ProJet 4500(3DSystems, Rock Hill, SC, USA)

Neuroendoscopy Simulator

Simulator Imaging

MRI T1 CoronalCT Axial MRI T1 Axial

Instrumentation

• Neuroendoscopy System (MINOP InVent, Aesculap, Inc., Center Valley, PA, USA)– 0o and 30o angled endoscope– Bimanual instrumentation – scissors,

forceps– Suction/Irrigation – 6-French NG Catheter

• Neuronavigation (StealthStation EM, Medtronic, Inc., Minneapolis, MN, USA)– Preoperative CT and MRI fusion– Fiducial- and surface-based registration– Field generator and skull-mounted

reference frame

Aesculap MINOP InVent

Procedure Setup

Endoscopic Colloid Cyst Resection

AS

Fo

TS

Th CP

CC

SP

CH

Participant Demographics (n = 15)Demographic Information n

Level of Training

Junior Resident (PGY 1-3) 7

Senior Resident (PGY4-6) 4

Fellow 4

Staff 0

Handedness

Right 14

Left 1

Previous Simulator Use

Yes 1

No 14

Surgical Experience (median [range])1 2 [0 – 13]

1Observer, assistant, or primary surgeon in an endoscopic or open colloid cyst resection

Feedback Survey Results

5-point Likert scale: 5 – strongly agree, 4 – agree, 3 – neutral, 2 – disagree, 1 –strongly disagree

Feedback Survey Results

5-point Likert scale: 5 – strongly agree, 4 – agree, 3 – neutral, 2 – disagree, 1 –strongly disagree

Recommendations

• Optimize orientation of the head to ensure ergonomic hand positions

• Increase brain compliance to ease cyst extirpation from the ventricles

• Increase case complexity for experienced trainees– Normal-sized ventricles

– Choroid plexus adherent to cyst wall (cautery)

– Increased cyst fluid viscosity (tissue shaver)

– Dense attachment of cyst to roof of third ventricle (fornix, internal cerebral veins)

– Intraseptal cyst location

– Bleeding scenarios

Conclusions

• Successfully built patient-specific silicone-based colloid cyst simulator

• Performed initial validation of simulator’s realism, procedural content, and value as training tool

• Future work– Further improve simulator realism

– Incorporate cautery, ultrasound, tissue shaver

– Increase case complexity

– Conduct additional validation studies (construct validity)

Overview of Fabrication Process of Metopic Model

DICOM CT/MRI -> Mimics Software -> Magics Software -> 3D Printing

Fig. 1. 3D Surface Model of Metopic Skull Segmented from DICOM Using Mimics (MaterialiseNV) (A.), Assembly of Reusable Model-Base and Cartridge Using Magics (Materialise NV)

(B.), Final Metopic Model Assembled (C.)

Course Station Setup

Stages of Sagittal Procedure

Summary of Questionnaire Results for Metopic Model (n =11)

Item Num.Questionnaire Item

Strongly

Disagree (1)

Disagree

(2)

Neutral

(3)Agree (4)

Strongly

Agree (5)

An

ato

my

1.Surface anatomy was realistic and appropriately detailed for planning and

performing the skin incisions.0 (0%) 0 (0%) 1 (9%) 6 (55%) 4 (36%)

2.Scalp and sub-periosteal tissue plane were realistic and had appropriate detail

for exposure of the anterior fontanelle and metopic suture.0 (0%) 0 (0%) 2 (18%) 6 (55%) 3 (27%)

3.The skull and anterior fontanelle, fused metopic suture and epidural space were

realistic and had appropriate detail required to perform the surgery.0 (0%) 0 (0%) 2 (18%) 4 (36%) 5 (45%)

Inst

rum

ent

Han

dlin

g

4. Endoscope handling was realistic 0 (0%) 0 (0%) 0 (0%) 4 (36%) 7 (64%)

5. Instrument handling was realistic 0 (0%) 1 (9%) 0 (0%) 2 (18%) 8 (73%)

6. The haptic (tactile) feedback from the simulator was realistic 0 (0%) 0 (0%) 1 (9%) 4 (36%) 6 (55%)

7.The response of the tissue to manipulation by the endoscope and instruments

was realistic0 (0%) 0 (0%) 1 (9%) 8 (73%) 2 (18%)

Co

nte

nt

of

Pro

ced

ure

8.Steps required to complete the task were representative of the steps for the real

procedure0 (0%) 0 (0%) 3 (27%) 5 (45%) 3 (27%)

9.Skills required to complete the task were representative of the skills required for

the real procedure0 (0%) 0 (0%) 3 (27%) 4 (36%) 4 (36%)

10. This task was technically challenging 0 (0%) 0 (0%) 3 (27%) 6 (55%) 2 (18%)

Task

Fid

elit

y

11. The simulator suspended disbelief 0 (0%) 0 (0%) 2 (22%) 4 (44%) 3 (33%)

12. The simulator environment is realistic of the real-life situation 0 (0%) 0 (0%) 1 (9%) 7 (64%) 3 (27%)

13. Real-life factors, situations & variables were built into the simulation scenario 0 (0%) 0 (0%) 2 (18%) 7 (64%) 2 (18%)

Table 2: Summary of Questionnaire Results for Sagittal Model (n=15)*

Item

NumberQuestionnaire Item

Strongly

Disagree (1)Disagree (2) Neutral (3) Agree (4)

Strongly

Agree (5)A

nat

om

y

1.Surface Anatomy was realistic and appropriately detailed for planning and

performing the skin incisions.0 (0%) 0 (0%) 1 (7%) 8 (53%) 6 (40%)

2.Scalp and subperiosteal tissue plane were realistic and had the appropriate

detail required for exposure of the anterior fontanelle and sagittal suture.0 (0%) 0 (0%) 1 (7%) 11 (73%) 3 (20%)

3.The skull and anterior fontanelle, fused sagittal suture and epidural space

were realistic and had appropriate detail required to perform the surgery.0 (0%) 1 (7%) 1 (7%) 8 (53%) 5 (33%)

Inst

rum

ent

Han

dlin

g

4. Endoscope handling was realistic 0 (0%) 0 (0%) 0 (0%) 6 (40%) 9 (60%)

5. Instrument handling was realistic 0 (0%) 0 (0%) 1 (7%) 6 (40%) 8 (53%)

6. The haptic (tactile) feedback from the simulator was realistic 0 (0%) 0 (0%) 3 (20%) 4 (27%) 8 (53%)

7.The response of the tissue to manipulation by the endoscope and

instruments was realistic0 (0%) 0 (0%) 1 (7%) 7 (47%) 7 (47%)

Co

nte

nt

of

Pro

ced

ure

8.Steps required to complete the task were representative of the steps

required to complete the real procedure0 (0%) 0 (0%) 0 (0%) 8 (53%) 7 (47%)

9.The skills required to complete the task were representative of the skills

required to complete the real procedure0 (0%) 0 (0%) 3 (20%) 5 (33%) 7 (47%)

10. This task was technically challenging* 1 (7%) 0 (0%) 4 (29%) 4 (29%) 5 (36%)

Task

Fid

elit

y 11. The simulator suspended disbelief* 0 (0%) 0 (0%) 4 (29%) 7 (50%) 3 (21%)

12. The simulator environment is realistic of the real-life situation 0 (0%) 0 (0%) 3 (20%) 8 (53%) 4 (27%)

13.Real-life factors, situations and variables were built into the simulation

scenario0 (0%) 2 (13%) 2 (13%) 8 (53%) 3 (20%)

* For Item 10 and Item 11, n = 14

Conclusions

• There are many applications for advanced technology in intracranial endoscopy both for simulation training, and tool development, including 3D printing, and robotics in their broadest sense.

• Advances in this area will be particularly relevant to other areas of neurosurgery as well as other surgical specialties

• Demonstrating efficacy, in terms of improved clinical outcomes, will be critical, both for simulation training, and novel tools, to justify their investment and costs.

• There will likely be an increasing role for surgical simulation in examination and certification