Image Assistance in TAVI Why CT › pdf › pdf › 2495_Won-JangKim.pdfImage Assistance in TAVI Why CT ? Won-Jang Kim, MD, PhD Clinical Assistant Professor of Medicine, Heart Institute,

Image Assistance in TAVIWhy CT ?

Won-Jang Kim, MD, PhDClinical Assistant Professor of Medicine, Heart Institute,

A M di l C t S l KAsan Medical Center, Seoul, Korea

Major Uses of CT in TAVIMajor Uses of CT in TAVI

• Ileofemoral Arterial Sytem :Patient Selection & PlanningIleofemoral Arterial Sytem : Size, Calcification, Tortuosity, Plaques

• 3D annular & root morphology & dimensions

Patient Selection & Planning

• 3D annular & root morphology & dimensions• Amounts of calcium in valve

D i I l t ti• Optimal angle (TF) or puncture site (TA)• Relationship of annulus to both coronary ostia

During ImplantationRelationship of annulus to both coronary ostia

• Merging Image during Implantation

• Post TAVI assessmentFollow-up

Evaluation of Access RoutesRoutes

Ileofemoral Artery Evaluation Ileofemoral Artery Evaluation

Ileofemoral Artery Evaluation Ileofemoral Artery Evaluation

Size Measure, Calcium distribution, Tortuosity,,,

Vascular ComplicationsVascular ComplicationsVascular ComplicationsVascular Complicationsascu a Co p cat o sascu a Co p cat o sPotential risk factorsPotential risk factors

ascu a Co p cat o sascu a Co p cat o sPotential risk factorsPotential risk factors

•• Patient relatedPatient related •• Device relatedDevice relatedPatient relatedPatient related-- Vessel SizeVessel Size-- CalcificationCalcification

Device relatedDevice related-- TAVI systemTAVI system-- SheathSheath

-- TortuosityTortuosity-- Vessel stenosisVessel stenosis

SheathSheath-- Guide wiresGuide wires-- BalloonBalloon

-- PlaquePlaque

•• Technique/operator relatedTechnique/operator related

-- Closure device Closure device CT Can Predict•• Technique/operator relatedTechnique/operator related

-- Aggressive manipulationAggressive manipulation-- Inaccurate calibration andInaccurate calibration and-- Inaccurate calibration and Inaccurate calibration and

measurementsmeasurements-- Poor controlPoor control-- Prolonged procedural timeProlonged procedural time

Femoral Artery Puncture under Femoral Artery Puncture under yFluoroscopic Guidance

yFluoroscopic Guidance

Anteriorsuperior

iliac spine Inguinaliliac spineInguinal

skin crease

gligament

Femoral

Commonfemoral

thead artery

SuperficialProfundaPuncture site, CFASuperficial

femoralartery

femoralartery

Initial Ileofemoral AortographyMade by Adw 4.5, GE healthcare system

Baseline Angiography & CT Baseline Angiography & CT

Made by Adw 4.5, GE healthcare system

Difficulty in Advancement S l ifi ll lDifficulty in Advancement

S l ifi ll lSevere calcific small vesselSevere calcific small vessel

Various Access Sites

TranssubclavianTransaortal

Transapical

T f lTransfemoral

Annulus sizingAnnulus sizing

Cannot be emphasized enough…

Clinician Publications: ImagingClinician Publications: Imaging

1. Sizing is an important part of pre-case planning for TAVI

2. Most current literature suggests a multi-modality approach and many prefer 3D method (MSCT)

Paravalvular Leak

Sizing and calcification are being investigated as major determinants of g jTAVI outcomes, for both Medtronic CoreValve® & Edwards Sapien®

Device size selection cannot be emphasized enough

Anatomy of Aortic Valvar Anatomy of Aortic Valvar ComplexComplex

Anatomy of Aortic Valvar Anatomy of Aortic Valvar ComplexComplexComplexComplexComplexComplex

Stability of valve Stability of valve probably probably

d t i d b thd t i d b th

Aortic Root thus composed of 3 rings andAortic Root thus composed of 3 rings and

determined by the determined by the “virtual ring”“virtual ring”

Aortic Root thus composed of 3 rings and Aortic Root thus composed of 3 rings and one crownone crown--like ringlike ring

Piazza, N. et al. Circ Cardiovasc Intervent 2008;1:74Piazza, N. et al. Circ Cardiovasc Intervent 2008;1:74--8181

Device Sizing Can Impact Procedural Device Sizing Can Impact Procedural g pOutcomes

g pOutcomes

• Significant variation exists in TAVI device• Significant variation exists in TAVI device selection

• Imaging modality differencesImaging modality differences• Definition of aortic annulus• Industry differencesIndustry differences• Physician preference and experience

• The aortic annulus is a non-circular structureThe aortic annulus is a non circular structure and proper imaging is important

• Several publications have demonstrated a pcorrelation between sizing and clinical outcomes

Aortic Annulus on CT

Mean = 1.29 ± 0.11

Circular Annulus is Very Small ProportionDistribution of Dmax/Dmin from 164 TAVI patients

Courtesy of Dr. Piazza and Prof. Lange, German Heart Center, Munich Germany

Circular Annulus is Very Small Proportion

A Limitation of Echoc

??

It is possible a true diameter is not measured due to the imaging plane acquired

Piazza N, et al. Circ Cardiovasc Intervent. 2008;1:74.

Low Correlation Between Echo & CT

MEAN DIAMETER

162 patients Low correlation between echo diameter and all CT derived measurements (major, minor, & mean diameters, perimeter, and area)

Courtesy of Dr. Piazza and Prof. Lange, German Heart Center, Munich Germany

CT is Highly Reproducible Compared to EchoEcho

Echo MSCT

Tzikas A, et al. Catheter Cardiovasc Intervent. 2011;77:868.

Aortic Annulus on MSCTAortic Annulus on MSCTCoronal measurements do not equal those from theCoronal measurements do not equal those from the

annular plane

MPRMPR

Coronal Image Oblique Coronal Image

Aortic Annulus

Aortic Annulus on MSCTAortic Annulus on MSCTSagittal measurements do not equal those from theSagittal measurements do not equal those from the

annular plane

MPRMPR

Sagittal Image Oblique Sagittal Image

Aortic Annulus

The Aortic Annulus on MSCT

Aortic RVOTAortic Annulus

RVOT

RALAA

Descending A t

LA

Aorta

New CT Parameters

Area-derived virtual Diameter√(4*Area/π)

Minimum DiameterArea

√(4 Area/π)

Elli ti it R tiEllipticity RatioMaximum Diameter/Minimum Diameter

Maximum Diameter

PerimeterDiameter

Perimeter-derived virtual DiameterPerimeter/π

CT Measurements of Aortic Annulus

Perimeter: linear distance of tracing around gthe aortic annulus

Area area contained ithin tracing aro ndArea: area contained within tracing around the aortic annulus

Major & Orthogonal Minor Diameters: linear distances through the center of the gaortic annulusMean Diameter: Calculated mean of major and minor diametersand minor diameters

TEE 3-Chamber Coronal Basal Mean Area-derived Rule of sineTEE vs CT (N=30) AMC data

TEE 3 Chamber Coronal

20.4±1.6 20.3±2.1 22.5±1.9 22.6±2.0 22.6±2.0 24.5±2.7

3-Chamber Coronal Basal Mean Area-derived Rule of sineInter-Reader Reliability by ICC (N=30)• CT measurements for annulus are usually larger than

echocardiography0.51 (.40-0.62) 0.75 (0.63-0.80) 0.80 (0.70-0.85) 0.81 (0.71-0.89) 0.81 (0.72-0.88)

Perimeter0 86 (0 9 0 92)

echocardiography

0.86 (0.79-0.92)

Intra-Reader Reliability by ICC (N=30)• Most reproducible CT measurements are perimeter3-Chamber Coronal Basal Mean Area-derived Rule of sine

1 0.72(0.47-0.88) 0.89(0.76-0.94) 0.94(0.84-0.96) 0.95(0.88-0.98) 0.94(0.85-0.97)

Intra Reader Reliability by ICC (N 30)• Most reproducible CT measurements are perimeter, area-derived, basal mean, and rule of sine method

2 0.51(.40-0.62) 0.93(0.84-0.97) 0.95(0.88-0.97) 0.96(0.89-0.99) 0.93(0.83-0.96)

Perimeter

0 97(0 93 0 98)

IIC, Intraclass correlation coefficient

0.97(0.93-0.98)0.95 (0.86-0.98)

Anatomic Implications for TAVI I iImaging

• The aortic annulus is clearly a complex structure and requires imaging that can take q g ginto account its elliptical and irregular shape

• Single diameter sizing methods can provide misleading results

• 3D imaging can provide a more accurate representation of the aortic annulusrepresentation of the aortic annulus

What to do with CT annular t tl ?measurements currently?

• Multidisciplinary approach - team members from the interventional and surgical teams reviewing g gaortic annuli with the CT and echo teams

• Root geometry and annular configuration by CT affords the implanting physician greateraffords the implanting physician greater understanding of the patient’s anatomy and allows for a more individualized TAVI approachfor a more individualized TAVI approach

What are the current recommendations?

What are the current recommendations?recommendations?recommendations?

Annulus size by TEE

26mm Valve

23mm Valve

Usually tend to oversize by at least 2mm on echocardiography

CT Sizing for CoreValveCT Sizing for CoreValve

6.45%91.129mm31mm

Cover IndexPerimeterDiameterValve Size

16 13%81 7263112.90%84.827mm31mm10.30%8828mm31mm

6 90%84 827mm29mm

16.13%81.726mm31mm

13.80%78.525mm29mm10.30%81.726mm29mm6.90%84.827mm29mm

11 50%72 323mm26mm

17.20%75.424mm29mm

19.20%6621mm26mm15.40%69.122mm26mm11.50%72.323mm26mm

23.10%62.820mm26mm

CT Sizing for Edwards ValveCT Sizing for Edwards Valvegg

Annular Area (mm2) Edwards valve size (mm)Annular Area (mm2) Edwards valve size (mm)

230 - 300 20

310 - 320 20 or 23

330 - 400 23

410 23 or 26

420 510 26420 - 510 26

520 26 or 29

530 - 660 29

Aortic root dimension and spatial relationship with surrounding relationship with surrounding

structures

LM

RCARCA

From annulus to LMCAFrom annulus to LMCA

LVLV

From annulus to RCA osFrom annulus to RCA os

Navigator For Transapical ApproachNavigator For Transapical Approach

Direction of Puncture or Wire


Aortic Valve MorphologyAortic Valve Morphology& Amount of Calcium

Scanty calciumScanty calcium

Heavy eccentric calcium

Vague Number of Leaflet Vague Number of Leaflet TTE

R/O Bicuspid AV

It is clearly Tricuspid Valve It is clearly Tricuspid Valve


Echocardiographic findings Echocardiographic findings It is hard to deterimine how much calcium is in valve

TEE TTE

Lack of Calcium Lack of Calcium

It is risk factor for migration or annulus rupture

Heavy Eccentric Calcium Heavy Eccentric Calcium


Heavy calcium on non-coronary cuspHeavy calcium on non-coronary cusp



Basal portionBasal portion

Top of valve


Valve Position & ImplantationValve Position & Implantationpp

LAO 1 CAUD 26 ; 26mm ValveLAO 1 CAUD 26 ; 26mm Valve

Final Aortogram

Echocardiographic evaluation

Mild to moderate PVL, No severe AR sign in pressure curve

Sudden Drop of Vital Sign,Embolized valve to LVOTEmbolized valve to LVOT

Major OperationMajor Operationj pj p

Removal of embolized Edwards valveRemoval of embolized Edwards valveAV Replacement (Magna 21 mm)Patient was cared in ICU.

Valve positioningp g

Line of Perpendicularity- Predicted A l

Line of Perpendicularity- Predicted A lAnglesAngles

Aortic Valve Plane by CT ScanAortic Valve Plane by CT Scan

RCCRCC

LCC

NCC

LAO CranialRAO Caudal

RCCLCC

NCC

RAO Caudal LAO Cranial

Merged Imaging Tools Merged Imaging Tools g g gg g g

Courtesy by Philips

Follow up evaluation

Examples of ConformabilityCoreValve Cases

Volume Rendering ImageVolume Rendering Imageg gg g

LM

RCA


Spatial relationship with surrounding structuressurrounding structures

Coronal ViewCoronal View

LM

RCA


Spatial relationship with surrounding structuressurrounding structures

Sagittal ViewSagittal View

LM


Double Oblique ViewDouble Oblique Viewqq

No Valve Migration, Fracture, Circumferentiality

New Imaging Modalitiesusing the CT image

DynaCT Image Acquisition with y g qrapid pacing

C t Si S tCourtesy Siemens Systems

Valve deployment under DynaCTValve deployment under DynaCT

Edwards SAPIEN CoreValve

Courtesy by Alois Nöttling Siemens

Edwards SAPIEN CoreValve

Courtesy by Brockmann German Heart Center Munich

Conclusion: Why CT?• CT is the only 3D method that:

- Allows for several measurements of the aortic annulus, including perimeter.

- Allows for complete patient assessment, including access routes (femoral subclavianincluding access routes (femoral, subclavian, or direct aortic).

- Allows for calcification assessment.

• MRI is limited by spatial resolution and calcification assessment is limited. Plus it is a more technically challenging technique to get the correct images. Better for hemodynamic evaluation (reconstruction can be challenging), flowg g),

• 3D echo is limited by spatial resolution, calcification, and does not readily allow for the , yassessment of access routes

Image Assistance in TAVI Why CT › pdf › pdf › 2495_Won-JangKim.pdfImage Assistance in TAVI Why CT ? Won-Jang Kim, MD, PhD Clinical Assistant Professor of Medicine, Heart Institute,

Documents