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