SHA24/071003

Interventions and innovations in pipeline for paediatric cardiology Shakeel A Qureshi Evelina Children’s Hospital London

Upcoming interventions • Not much change in interventional procedures over the last 5 years • Interventions in next 5 years will be similar • However, there will be more registry or other data to provide evidence • More adult congenital heart interventions • More new device changes e.g biodegradable stents • There will be increasing hybrid procedures

Earlier inventions • Catheter pulmonary valvotomy (in Mexico in 1953) • Rashkind septostomy in 1966 • Catheter ASD closure (King & Mills in 1976 • Some fell out of favour whilst others survived (BAS) because: – The inventors did not pursue – Technology was not good – Industry support was lacking

Established interventions today •

Balloon dilation: – Pulmonary valve stenosis at all ages – Aortic valve stenosis at all ages

•

Catheter closure: – PDA by coils or devices – ASD by devices – VSD by devices – Coil occlusion of MAPCAs, AV malformations etc

•

Stent dilation: – Peripheral PS – Aortic coarctation in adolescents and adults.

Palmaz stent

Palmaz Genesis stent

Stainless steel balloon-expandable

Stent : Extra Large:

Andrastent (Andramed) CP (Numed)

Stent implantation for pulmonary artery stenosis Open cell stents

More recent trends • Stenting of RVOT in tetralogy of Fallot in neonates • Stenting of PDA in duct-dependent cyanotic CHD

RVOT stenting in tetralogy of Fallot Whole of RVOT should be covered

RVOT stenting in tetralogy of Fallot

Ductal stenting Originally, a novel but risky approach, but with improvement in stent design & delivery platforms it is considered today as an alternative to surgical shunts

Tricuspid atresia, PDA PDA stenting via femoral artery route

Alwi M, IJN, Kuala Lumpur

Pulmonary artery growth PDA stent vs BT shunt

Uniform growth after duct stents

Santoro et al

Covered Stents in Paediatric Cardiology

Stent for aortic coarctation

Aortic interruption

Treated with a covered stent

Trends in interventions • Fetal balloon dilation of aortic and pulmonary valves • Fetal atrial septostomy • Catheter replacement of pulmonary valve • Catheter replacement of other valves • MRI based catheterisation and interventions • Hybrid procedures (eg. Completion of Fontan)

Balloon dilation of aortic valve in fetus

Wayne Tworetzky

Fetal intervention Pulmonary atresia/IVS

Gurleen Sharland

Fetal interventions in future • The evidence base for these will increase • These techniques likely to continue although currently they may have questionable benefit • Improved technology may allow much earlier interventions and so may influence the outcome

Hybrid theatres and procedures Hybrid Cardiac Operative Suite, Columbus, Ohio

Hybrid Therapy for CHD • Provide surgical access for interventions • Extremely premature neonates • Hybrid for HLH • Aortic stenosis with poor LV function or borderline LV size • Perventricular closure of MVSD • Intraoperative stents • Exit diagnostic angiography • Hybrid valve implantation

Successful balloon pulmonary valvoplasty in 700 gm baby RV fx improved, ascites resolved, baby discharged

Hybrid approach essential for success

Courtesy: John Cheatham

Stage I Palliation

Comprehensive stage I & II

Transcatheter Fontan

Hybrid procedure for HLH with absent left lung

Now age 6 years after single lung Fontan

Hybrid procedures for VSDs 4 month old, 4 kg; large anterior muscular VSD

Hybrid LPA stenting

Dilated RVOT with tortuous LPA origin

Hybrid stent implantation for disconnected LPA

This collaborative hybrid approach reduces the risk of procedure

Exit Angiography

Catheter valve replacement • Pulmonary valve - clinical • Aortic valve – clinical • Tricuspid valve - clinical • Mitral valve - experimental

Percutaneous implantation of the pulmonary valve

Melody valve Sapien valve

Introducer sheaths for percutaneous pulmonary valves Melody introducer: 22 Fr OD Sapien sheaths: 25 to 28 Fr OD 25 F

Sheath Set

Internal Diameter

Outside Diameter

Length

23 mm

22F

8.4 mm

35 cm

26 mm

24F

9.2 mm

35 cm 28 F

Melody valve implantation Prestenting with covered stent in calcified RVOT

Implantation of Melody valve in a prosthetic tricuspid valve

Hybrid Perventricular Melody valve off CPB

Courtesy: John Cheatham

Delivery of the Melody valve

Courtesy: John Cheatham

Catheter valve replacement Pulmonary valve • Challenges of large RVOT remain • Techniques being evaluated to reduce the RVOT dimension

Surgical implantation of Melody valve • Surgical Melody Valve Implantation in Infancy • Using Melody valve as surgical conduit for RVOT • With growth of patient, Melody valve can be dilated with a balloon • Experience of 7 babies so far

Pedro del Nido, Boston

RV-PA conduit • Implantation Technique – Attach sewing cuff of stretch PTFE – In situ implantation within native RVOT PA

RV

• Late evaluation for effect of redilation Pedro del Nido, Boston

Melody RVOT conduit • Patients

8

• Age (median)

8mo (1.6mo-6.6yrs)

• Diameter at implant 12mm (9-18mm) • Follow-up (18mo) • Replacement in 2 • Re-dilation in 5 (mild PR)

Account for growth RV Outflow Reconstruction

Mitral Valve Replacement •

N=

7

•

Age

3mo (1-12)

•

Pathology

•

– MR

6

– MS

1

Technique – Crimped to 10mm, sewn to native leaflets, expanded in situ – Cuff of autologous pericardium for annulus fixation

•

Follow up – 1 death (slavage procedure from ECMO) – 2 redilated (3 and 4mo post implant) – 1 explanted at Tx

Mitral valve replacement using Melody valve

• 6 months post implant presented with para prosthesis leak

Evolution of the Integration

Roadmapping • Image modalities for EP • Image Fusion/Registration Techniques • Applications • Image-based guidance • Image-based predictive modelling

Advances in imaging which help interventions • • • •

3-D and 4-D echocardiography 3-D CT angiography 3-D MRI Rotational angiography

DynaCT: 3-D reconstruction

3D Rotational Angiography (3DRA) 240O acquisition over 4 sec No standards for technique Room set-up

- Monitoring - Anesthesia/airway

Contrast injection

- Amount - Initiation / Duration - Dilution

Patient related issues

- Anatomy - Breath-hold - Artifact

Tom Fagan, Denver, 2013

Rotational Angiography

Coronary artery assessment prior to Melody valve

Imaging pulmonary arteries in patients with TCPC

In TCPC pts, PAs should be unobstructed With 3DRA, subtle abnormalities may be seen

Pulmonary valve balloon with 3D reconstruction and roadmapping.

A - 3D rendering of a non-gated right-sided cardiac C-arm CT reconstruction B - Overlay of the 3D pulmonary artery from A (red outline) onto live fluoroscopy during balloon valvuloplasty of the pulmonary valve

Schwartz et al, 2011

Interventional Guidance 3DRA Roadmapping

6 yo HLHS post Fontan with RPA Stenosis

Interventional Guidance 3D RA Roadmapping

a

b

c

Melody and pre-Melody stent placement Schwartz, Int J Cardiovasc Imaging. 2011 Dec;27(8):1205-22

TOE registration with fluoro for transseptal puncture

Courtesy: Kawal Rhode., KCL

Current / Near Future Projects Echo Navigator (EchoNav) Para-valvar mitral leak closure

Courtesy:John Carroll, Denver

MRI image overlay Stenting of aortic coarctation

MRI guided interventions without fluoroscopy

Balloon dilation of coarctation

MRI guided interventions without fluoroscopy

Balloon dilation of PVS

True Overlay

Future directions •

Many techniques and technologies are being developed

•

If suturing inside the heart becomes practical, then perhaps ASDs could be closed without devices

•

Hybrid suites (surgeons and interventionalists working together) will develop

•

Catheter lab and theatres will combine

•

Exit angiography will assume importance

•

MRI compatible catheters and devices will reduce the need for radiation for interventional procedures