Role of Interventional
Catheterization in Post-Operative
TOF Patients
Jennifer Rutledge, MD
October 25, 2013
What is our role?
• To keep patients with TOF away from the
surgeons as long as possible
What is our role?
• Treat / palliate the residual lesions patients
may be left with and delay the need for future
cardiac surgery
• Hopefully to improve outcome and quality of
life
Outline
• When, Why and How?
– Timing of intervention
• Immediate post-operative versus later
– Palliative procedures versus complete repair
• Shunts
• Pulmonary arteries
• Conduits and Valves
Timing of Intervention: Early Post-Op
• Patients who have difficulty recovering after
surgery have a higher incidence of residual
lesions
• Diagnostic cath can be performed safely in the
early post-op period and often results in the
discovery of lesions that require further
intervention
Timing of Intervention: Early Post-Op
• Interventional cath has historically been
avoided in the immediate post-op period
• Concerns:
– Transport of critically ill patients
– Worsening clinical status as a result of the
procedure
– Fear of disruption (rupture) of fresh suture line
Timing of Intervention: Early Post-Op
• Commonly thought a minimum of 6 weeks of
adequate scar tissue formation is required for
safe intervention
• Recent data suggests intervention can be
performed safely < 6 weeks
• Performance of successful catheter
intervention can improve survival to discharge
Timing of Intervention: Early Post-Op
• Intervention only considered if the lesion is
severe enough to compromise clinical status and
repeat surgery is considered to be high risk
• Requires multidisciplinary team
•
•
•
•
•
•
•
Interventional cath doc
Surgeon
Intensivist
Anesthesiologist
Nurses, RT, anesthesia and radiology technicians
ECMO team
Operating room team including nursing and perfusion
Timing of Intervention
• Timing of catheterization outside of the
immediate post-op period is largely based on
non-invasive imaging and standard criteria
– Significant right ventricular outflow tract
obstruction
– Branch pulmonary artery stenosis
– Severe pulmonary valve regurgitation
Types of Intervention: Neonatal Shunts
• Rarely performed in this population
– Anomalous coronary artery
– Multiple large VSD’s or TOF/AVSD
– Contraindication to bypass
• Central versus modified Blalock-Taussig shunt
Shunts
• Shunt obstruction can occur 3-20% of cases
– Thrombosis, suture line stenosis, intimal
proliferation, vascular distortion, ductal tissue
constriction
– Results in cyanosis of the patient – can be lifethreatening
– Most often occurs acutely after surgery but can
occur late
– Risk factors: small shunt and pulmonary artery
size, polycythemia, competitive blood flow
Shunts
• Interventional cath options:
– Mechanical or pharmacological disruption of clot
• Goal is to break up the clot and dislodge it distally,
improving flow across the shunt
• Can be achieved manually by using
catheters/wires/balloons but only useful for fresh clot
• May be achieved by local thrombolysis or
thrombectomy
– Local injection of TPA – often requires prolonged infusions
» Not practical for shunts or fresh post-op patients
Shunts
• Shunt thrombosis most often develops in
association with a stenosis of the shunt and/or
adjacent blood vessel
– Balloon dilation or stenting performed to disrupt
the clot and treat the stenotic lesion
– In the immediate post-op period stenting likely
safer
• More predictable and durable result, less recoil of
vessel, smaller balloon/stenosis ratio for effective
expansion
Shunts
Shunts
Shunts
Pulmonary Arteries
• Branch pulmonary artery stenosis is a wellknown association in TOF population
– Post-surgical: at suture line (shunts, proximal
branches), ductal constriction
– Native: proximal or distal branches
• Balloon dilation or stenting
– What type of intervention is determined by
patient/vessel size and anatomy, timing of surgical
intervention (past, present and future)
Pulmonary Arteries
• Lots of toys
– Regular balloons
– High pressure balloons
– Ultra-high pressure balloons
– Cutting balloons
Pulmonary Arteries
• Intravascular Stents:
– Ideally we like to implant stents that can be
further dilated to adult size
– Depending on the patient size, this is not always
possible
• Place smaller stents that will then need to be cut across
at the time of subsequent surgery
Pulmonary Arteries
Bergersen L et al. Cardiol Young 2005;15:597-604
Pulmonary Arteries
Bergersen L et al. Cardiol Young 2005;15:597-604
Pulmonary Arteries
Pulmonary Arteries
Pulmonary Arteries
Angtuaco, M. et al. Cathet Cardiovasc Int. 2011;77:395-399.
Pulmonary Artery Growth
Conduits
• Frequently used in patients with TOF at
various stages of life
• Conduits fail due to stenosis and/or
regurgitation
• Freedom from conduit replacement 68-95% at
5 years and 0-59% at 10 years
• Surgical conduit revision may be delayed in
some patients by cath intervention
Conduits
• Balloon dilation alone
rarely achieves good
result
• Contraindication to
conduit stenting
– Anomalous coronary
artery positioned behind
the conduit
• Risk of coronary
compression
Conduits
Freedom from conduit
surgery
Peng LF et al. Circulation 2006;113:2598-2605.
Conduits
• Risk factors for need for earlier re-intervention
– Younger age, higher pre-stent RV pressure,
diagnosis OTHER than TOF, homograft conduits,
conduits ≤ 10 mm
• Stent fracture seen in 43%
– 89% immediately behind the sternum
– 82% had compromise of the integrity of the stent
Peng LF et al. Circulation 2006;113:2598-2605.
Conduits
Chronic Pulmonary Regurgitation
• Any patient with transannular patch repair
• Majority of patients following conduit or
bioprosthetic valve implantation
• Ultimately all patients with TOF will require
therapy (repeated) for chronic PR
Transcatheter Valves
• Developed to treat dysfunctional bioprosthetic
valves or conduits and reduce number of and
prolong time to next surgical intervention
• Two current options
– Medtronic Melody valve
– Edwards Sapien valve
Melody Valve
• Bovine jugular vein; platinum/iridium
stent
• Available in Canada since late 2005; as of
May 2013 there have been over 5000
implants in 180 centers in 35 countries
– ~50% have underlying diagnosis of TOF
Melody Valve
• Can be considered in patients:
– > 30 kg, vessels large enough to accommodate the
22F sheath
– Implant site 16-22 (24) mm in diameter
– Evidence of conduit/valve dysfunction
Melody Valve
www.medtronic.com
Melody Valve
US IDE
UK
German
Italian
Canadian
100
90
Patients, %
80
70
60
50
40
30
20
10
0
Regurgitation
Stenosis
Mixed
Courtesy Medtronic
Baseline Patient Characteristics
Conduit Type
Melody
Valve
US IDE
UK
German
Italian
Canadian
100
Patients, %
90
80
70
60
50
40
30
20
10
0
Homograft
Bioprosthetic
Synthetic/other
Courtesy Medtronic
Long-term Outcomes
Long
Term
Pulmonary
Valve
Competence
Pulmonary
Valve
Competence
by Echocardiography
6 months
100%
90%
None
Trace
Mild
Moderate
Severe
Patients, %
80%
70%
60%
50%
40%
30%
20%
10%
0%
US IDE
UK
Canadian
1 year
100%
None
Trace
Mild
Moderate
Severe
Patients, %
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
US IDE
UK
3 years
Canadian
100%
90%
None
Patients, %
80%
70%
Trace
60%
50%
Mild
40%
Moderate
Severe
30%
20%
10%
0%
US IDE
UK
Courtesy Medtronic
Canadian
Courtesy Medtronic
Melody Valve
• Freedom from re-operation:
– Canada: 91%, 83% and 83% at 12, 24 and 36
months, respectively
• Freedom from transcatheter intervention
– Canada: 91% 1 year, 80% 2 year
Courtesy Medtronic
Complications
Stent Fractures
(%)
Melody Valve:
Complications
Patients, %
• Stent fracture in 5-25%
– Increased use of pre-stenting of conduits reduces this
risk
• Conduit rupture - ~4% requiring treatment
(covered stent/surgery)
– <1% “uncontained” rupture but can be fatal
• Coronary artery compression
28
12
30
7.5
– Can be seen24in ~5%
of
patients
during
test evaluation
Follow up (months)
– Can be catastrophic
Morray BH et al. Circ Cardio Int;2013:6:535-542
Transcatheter Valve
• Melody valve was expanded the role of
interventional cath in post-operative patients
• Limited size range
• There are many patients with conduits and
valves that are not candidates for a Melody
valve
Sapien Valve
• Bovine pericardial valve leaflets hand-sewn into a
slotted stainless steel stent
• Fabric sealing cuff on lower portion of stent
• Designed for aortic position
• Can be considered for pulmonary valves/conduits
~21 - 30 mm in diameter, patients > 30-35 kg
• Shorter stent requires that conduits are fully
stented prior to Sapien valve insertion
Edwards Lifesciences
Sapien Valve
Sapien vs. Melody
Faza et al. Cathet Cardiovasc Int 2013;82(4):E535-41.
Sapien vs. Melody
Faza et al. Cathet Cardiovasc Int 2013;82(4):E535-41.
Transannular Patch
• What about the really large RVOT’s?
• Medtronic Native Outflow Tract Pulmonary
Valve
Courtesy Medtronic
Medtronic’s Early Feasibility Study:
Non-randomized, Prospective
• Primary Objective:
– Obtain in vivo data to confirm assumptions on loading conditions for
future in vitro frame evaluations
• Secondary Objectives:
– Characterize procedural feasibility, safety & TPV performance
• Up to 20 subjects - Consented for 5 year follow-up at 3 North
American Centers (Implants spring 2014 – F/U to 2019)
– The Hospital for Sick Children ,Toronto Canada – Dr. Lee Benson
– Nationwide Children’s Hospital, Columbus Ohio – Dr. John Cheatham
– Children’s Hospital, Boston MA – Dr. Jim Lock
Courtesy Medtronic
Courtesy Medtronic
Conclusion
• Patients with TOF are left with residual lesions
• Cardiac cath lab procedures can treat or
palliate many of these lesions and delay the
need for repeat cardiac surgery
• Future advances will expand the therapeutic
options to include a broader range of patient
diagnoses and patient sizes