1/9/2018

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3D Printing &Echocardiography

Echo HawaiiJan 18, 2018

Stephen H. Little, MDJohn S. Dunn Chair in Cardiovascular Research and Education, Associate professor, Weill Cornell Medicine

Rapid Prototyping 101

Complex Geometry + Multi‐Material Fusion  =  Functional Anatomy (?)

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Finish this sentence….At my institution we use 3D printing to:1. Plan all complex structural heart procedures.2. Plan for selected complex structural heart procedures.3. As a research tool with very little clinical usage.4. What the heck is 3D printing? We never use it.

ARS Question # 1Audience poll

Finish this sentence….At my institution we use 3D printing to:1. Plan all complex structural heart procedures.2. Plan for selected complex structural heart procedures.3. As a research tool with very little clinical usage.4. What the heck is 3D printing? We never use it.

ARS Question # 1Audience poll

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Anatomic Teaching Tools

DeviceInnovation

Functional Flow Modeling

ProceduralPlanning

CV 3D Print Applications

The 3D printing steps

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AVA Replication

Maragiannis et al. Circ Cardiovasc Imaging. 2015

Aortic Root Replication

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HeartBeat Simulator™ Setup

ArterialCompliance

ChamberArterial

ResistanceClamp

FlowProbe

VenousReservoir

PulsatilePump

Flow Probe

Patient‐Specific LVOT Model

Mechanical Mitral Valve

Pressure Tx

Pressure TxPlan to TAVR

Calcific AorticValve Stenosis Model

Patient‐Specific LVOT Model

Pulsatile flow across a 3D printed model

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0

1

2

3

4

5

6

7

8

9

0.00 0.01 0.02 0.04 0.05 0.06

Stress (MPa)

Engineering Strain 

Calcific Compression Test

0

0.05

0.1

0.15

0.2

0.25

0.00 0.17 0.33 0.50 0.67 0.83

Stress (MPa)

Engineering Strain 

Tensile Test

E= 62 MPa E= 0.4 MPa

Compression testing for rigid calcific nodules and tensile testing for soft tissue structures. 

Mechanical Testing of Print Materials

Replicating AS pressure gradients

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0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

30 50 70 90

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 1

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

30 50 70 90

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 2

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

40 75 110 145

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 3

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

30 50 70 90

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 4

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

30 50 70 90

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 5

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

30 50 70 90

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 6

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

40 75 110 145

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 7

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

40 75 110 145

AV

A (

cm2)

Stoke Volume (ml/beat)

Patient 8

ClinicalModel

Gorlin AVA

Doppler AVA

Doppler AVA

Replicated AVA flow dependency

Maragiannis et al. Circ Cardiovasc Imaging. 2015

Aortic Regurgitation: Doppler Replication

3D Model AR

Hemodynamic Parameters: Patient ModelRegurgitation Time: 460 ms 458 msPeak Velocity: 4.6 m/s 4.7 m/sPressure half time: 312 ms 331 msTime-velocity index: 167 cm 162 cm

Patient AR

LV

LV

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CoreValve Prosthesis Sheathed Transcatheter CoreValve Prosthesis

Crossing Stenotic Aortic Valve

CoreValve Deployment CoreValve Expanded Within LVOT Model

Depth 4mm

Bench‐top TAVR

Replicating PVL 

Patient Echo

Model Echo

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3D TEE Data

Mitral Valve reconstruction from 3D TEE  

3D printed multi-material mitral valve model

Digital patient-specific multi-layer 3D MV model

AP

PL

Coronal planeAxial plane

Segmentation of target anatomy

STL file

Segmentation software

AL

PL

Mechanical Testing of Mitral Valve Materials

AL

PL

Bending test Tension testingM. Vukicevic et al.  Ann BioMed Eng. (2016)

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Porcine mitral valve anterior leaflet

Porcine mitral valve posterior leaflet

Tangoplus S35 modulus = 0.53 MPaTangoplus S35+S27 modulus = 0.46 MPaTangoplus S27 modulus = 0.38 MPa

Modulus = 3.7 MPa

Modulus = 2.6 MPa

Modulus = 3.7 MPa

Tension Testing

Mitral Leaflet Response to Stress

M. Vukicevic et al.  Ann BioMed Eng. (2016)

P2 perforation & central MR

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Pre‐procedural Planning of perforated mitral valve repair

Patient-Specific 3D PrintP2 perforation

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What device will fit?

Patient-Specific 3D PrintModeling for Leaflet Repair

Atrial View

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Ventricular View

Replicating  the calcium too 

MitraClip @ A2/P2ASD occluder within P2

Little et al. JACC Interventions (2016)

Guiding the practiced procedure

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The Never Ending story dog

A familiar result?

Modeling LVOT obstruction

M. Vukicevic, S.Little et al.  JACC Img. (2017)

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CT‐based patient‐specific MV

Mitral valve 3D printing

M. Vukicevic, S. Little et al.  JACC Img. (2017)

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AL

MV model

MitraClip MitraClip implantation

MitraClip implantation in a patient‐specific 3D printed MV apparatus  

Why do we need models?

3D‐Printed Valve models:

Can replicate patient‐specific geometry Can be coupled to physiologic flow

Provide a reproducible testing environment Are a cheap arena for mistakes and innovation Have already changed how we practice and 

perfect structural heart interventions

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Stephen H. Little, MDshlittle@houstonmethodist.org