2. Surgical correction of tetralogy of Fallot through a classic right ventriculotomy has
been performed since 1955
Surgical repair for tetralogy of Fallot (TOF) often requires a transannular incision to
relieve right ventricular (RV) outflow obstruction.
This results in pulmonary insufficiency and may lead to progressive RV dilatation,
RV dysfunction, and a propensity towards arrhythmias
Pulmonary regurgitation following total correction for tetralogy of fallot is
associated with early and late morbidity and mortality
Pulmonary insufficiency is a leading cause of re-operation in patients following
total correction of ToF
3. Why is it important?
Tetralogy of Fallot is the overall commonest cyanotic congenital heart disease
Modern surgical techniques, better myocardial preservation and refined post-
operative care has led to excellent outcome and long term survival in repaired
patients
Patients of repaired TOF with pulmonary regurgitation form a major bulk in Adults
with Congenital Heart Disease (ACHD) aka GUCH patients
Pulmonary regurgitation is the most evident cause of late RV failure in operated
cases
Delay in addressing the problem can lead to permanent RV dilatation with failure of
remodelling
5. Historical thinking regarding post repair TOF physiology has emphasized two
points.
Firstly, postoperative RVOTO has been considered to be undesirable, to the point that
some teams would consider revision of a repair in the setting of a right ventricle RV/left
ventricular (LV) systolic pressure ratio >0.75.
The second "traditional" belief is that postoperative PI will be well tolerated in the longer
term, and that only very significant RV dilation will be problematic.
Both concepts have been challenged in recent years.
PI is exacerbated by loss of downstream compliance and lessened or prevented
by proximal resistance.
The degree of PI therefore depends in part on pulmonary artery (PA) compliance,
and the location of resistance relative to a valveless RV-PA junction
Free PI causes RV dilation that in turn affects the LV. The functional reserve and
myocardial contractility of the RV and LV may decline with chronic PI
6. Severe RV dilation and related dysfunction, RV wall motion abnormalities,
syncope, QRS duration >180 minutes, and sustained ventricular tachycardia all
predict late heart failure and sudden death
Liberalisation of indications for PV replacement is currently recommended in an
attempt to avoid the aforementioned scenarios
Not all patients will benefit, however, and the timing and exact indications are
controversial.
There is no consensus regarding the best tools for assessment, nor their relative
importance in decision making regarding significance of PI.
In balancing pulmonary stenosis (PS) and PI, it would therefore be useful in the
clinical setting to know which is worse for the RV and LV over the long term:
isolated PI or combined PS-PI.
7. Should we try to limit PI by accepting more
PS at the initial repair?
8. EXPERIMENTAL EVIDENCE
University of California San Francisco investigators have created a non-surgical porcine
model to assess the effects of chronic combined PS-PI on the RV and LV, looking at
both anatomic and functional changes
Growing pigs had transcutaneous stents placed across the Right ventricular outflow
tract (RVOT) and PV to induce PS-PI.
Assessment was done within 2 days of intervention and 3 months later, looking at
indices of systolic function (stroke volume, ejection fraction, and cardiac functional
reserve), myocardial contractility (slope of the end-systolic pressure-volume and
change in pressure over time-end-diastolic volume relationship, and diastolic
compliance.
MRI was used to quantify PI and ventricular volumes. Conductance catheters were
used to obtain indices of the cardiac functional reserve, diastolic compliance, and
myocardial contractility from pressure-volume relations acquired at rest and under
dobutamine infusion.
The data were compared with data from controls and animals with isolated PI
9. After 3 months of PS-PI, indices of RV
systolic pump function were diminished
at rest and failed to increase
appropriately during dobutamine
stress.
Impaired systolic pump function was
associated with decreased RV diastolic
compliance but enhanced RV
myocardial contractility.
These findings contrasted markedly
with the effects of isolated PI observed
in a similar model.
In addition, PS-PI resulted in a smaller
regurgitant fraction, more RV
hypertrophy, and a smaller increase in
RV volumes than did isolated PI.
10. PS in addition to PI seemed to have been beneficial by promoting hypertrophy,
limiting RV dilatation, and enhancing myocardial contractility.
These beneficial effects of short to intermediate term stenosis on RV myocardial
contractility raise many questions in light of the known adverse effects of long term
severe PS on RV function.
However, this also brings into question the long-held belief that stenosis, even
mild, is detrimental to RV function while insufficiency is well tolerated.
The acute change from a pressure loaded to a volume loaded RV, in addition to
the right ventriculotomy, can adversely affect the performance of the RV in the
immediate postoperative period.
A number of valve sparing techniques have been advocated across the years,
including commissurotomies, rigid or balloon intraoperative dilation, and even
acceptance of systemic RV pressure in order to maintain competence of a
moderately restrictive valve
11. Pulmonary regurgitation after repair
Causes reduced exercise capacity regardless of RV systolic pressure
RV systolic function and RVEDV are deranged
More the PR, more is the EDV
A pressure overloaded RV, with poor compliance, does not tolerate volume
overload and fails
Decrease in ejection fraction correlates with increase in RVEDV
Enlarged RV above 150-170ml/m2, fail to remodel, even after making the
pulmonary valve competent
RV dilatation is associated with wide QRS & increased risk of sudden deaths
12. When pulmonary regurgitation?
Following placement of a trans-annular patch across RV-PA junction
Repair of ToF with absent pulmonary valve without valve conduit
ToF with pulmonary atresia
Deformation/ calcification of pulmonary valve leaflets
13. How to measure PR?
Echocardiography
The quantification of pulmonary regurgitation (PR) requires the interpretation of different
echocardiographic parameters combined in a semi-quantitative assessment.
Color Doppler flow imaging of the RV outflow tract and the central pulmonary arteries is
one of the most commonly used techniques
Diastolic flow reversal in mild PR originates from the main pulmonary artery (PA),
moderate PR from the PA bifurcation and severe PR from the distal pulmonary artery
branches.
Apart from the origin of the flow reversal, the width of the color jet can also be measured
at the level of the pulmonary valve
14. How to measure PR?
The width of the PR jet can be compared
relative to the RV outflow tract (RVOT).
PR can be classified as
mild (jet width to RVOT ratio < 0.2)
moderate (ratio between 0.2-0.5)
severe (ratio > 0.5)
In patients after repair of TOF the
delineation of the pulmonary annulus is
often difficult and the outflow tract shape
is commonly non circular due to geometric
modification related to the patch repair.
Additionally there may be multiple jets of
regurgitation, which further complicates
the use of this technique.
15. Vena contracta, the narrowest area of blood flow exiting the valve is often utilized
in other regurgitant lesions, but it has not yet been validated in pulmonary
regurgitation
The proximal isovelocity surface area (PISA) is an additional color flow Doppler
based measurement that employs the flow convergence principle.
PISA is equal to the flow rate at the regurgitant orifice, and can be used to
calculate the maximal effective regurgitant orifice area and the regurgitant volume
In the setting of severe or free regurgitation, often seen in TOF patients, the PISA
method is not applicable.
16. Continuous wave (CW) Doppler traces of the
RVOT flow can also be helpful in the
assessment of the degree of PR.
More severe PR will result in faster equalization
of pressures between the PA and the RV in
diastole, resulting in a shorter pressure half-time
and progressive shortening of the backflow, with
prolongation of the no flow time in diastole
A pressure half time (< 100 milliseconds) and a
no-flow time (> 80 milliseconds) have been
shown as the useful parameters for identifying
severe pulmonary regurgitation
In a restrictive RV, a short pressure half-time will
reflect an increase in RV end-diastolic
pressures. This must be considered when
interpreting these Doppler timings.
17. Cardiac Magnetic Resonance (CMR)
CMR is accepted as the imaging modality of
choice for the quantification of PR and
assessment of RV size and systolic function.
CMR evaluation is recommended during the
routine follow-up of patients after TOF repair
PR expressed volumetrically, rather than as a
percentage of antegrade MPA flow, is a more
appropriate method for quantification
NMR velocity mapping is an accurate and
noninvasive method for volumetric
quantitation of pulmonary regurgitation in
patients after surgical correction of tetralogy
of Fallot.
18. When to intervene?
ACC/AHA Guidelines
Patients with repaired tetralogy of Fallot should have at least annual follow-up with a
cardiologist who has expertise in ACHD. (Class I, Level of Evidence: C)
In adults with repaired tetralogy of Fallot, catheterization may be considered to better
define potentially treatable causes of otherwise unexplained LV or RV dysfunction,fluid
retention, chest pain, or cyanosis.(Class IIb, Level of Evidence: B)
Pulmonary valve replacement is indicated for severe pulmonary regurgitation and
symptoms or decreased exercise tolerance. (Class I, Level of Evidence: B)
Pulmonary valve replacement is reasonable in adults with previous tetralogy of Fallot,
severe pulmonary regurgitation, and any of the following(CLASS IIA):
a. Moderate to severe RV dysfunction. (Level of Evidence: B)
b. Moderate to severe RV enlargement. (Level of Evidence: B)
c. Development of symptomatic or sustained atrial and/or ventricular arrhythmias.Level of
Evidence: C)
d. Moderate to severe TR. (Level of Evidence: C)
No definite guidelines regarding timing of intervention present.
20. Monocusp valve
A monocusp may be created with
Autologous pericardium
Bovine pericardium
Homograft pulmonary valve cusp
PTFE pericardial membrane (0.1mm PTFE patch)
It has shown, particularly in the immediate postoperative period, to prevent
pulmonary valve insufficiency
This may be associated with faster recovery of RV function, a lower central venous
pressure, and less chest tube drainage.
The construction of the monocusp is simple, very inexpensive, and reproducible.
The potential disadvantage in comparison to insertion of a pulmonary valve or
valved conduit is that, at least in some patients, there appears to be a faster
progression to recurrent pulmonary valve insufficiency, although late stenosis is
rarely, if ever, seen using this technique.
21. Monocusp valve
The patient is placed on cardiopulmonary bypass with aortic and bicaval venous
cannulation
Vertical incision is made in the main pulmonary artery
Through this incision the pulmonary valve and annulus is inspected. If possible, a
pulmonary valvotomy can be performed and the annulus measured with dilators.
In patients with moderate to severe hypoplasia of the annulus (generally more than 1
mm smaller than a -1 Z value), a transannular repair can be performed with the use of
the monocusp.
The other indication for the use of the monocusp would be a post-repair RVOT gradient
greater than 25-30 mmHg following a valve-sparing attempt.
This portion of the operation can be performed after the ventricular septal defect has
been closed and the aortic cross clamp removed.
22. Monocusp valve
The ventriculotomy is carried onto the RV only as far as necessary to alleviate the
infundibular narrowing.
This incision in general is 1-2 cm in length, but may be longer in patients with a
long, narrowed infundibular septum.
The ventriculotomy is also longer if transventricular rather than transatrial VSD
closure is to be performed.
At the mid-point of the incision, usually the site of the pulmonary valve annulus, the
edges of the ventriculotomy are retracted with stay sutures.
The functional remnant of pulmonary valve leaflets posteriorly are left intact.
23. Monocusp valve
A bullet-shaped piece of pericardium is fashioned
The membrane is placed in the ventricular portion of
the opening, allowing it to lay flush along the
ventricular walls and conal septum, thereby
maximizing surface area coaptation.
The edges of the patch are traced with a marking
pen according to their point of contact with the
epicardial surface and the material is cut to the
dimensions
The monocusp must be longer, obviously, for a
patient with a longer ventriculotomy. This is a key
technical point.
The monocusp is not constructed to approximate
the size of the remaining pulmonary valve leaflets, it
is constructed to approximate the size of the
ventriculotomy opening.
The leading edge of the proposed monocusp is
actually flat.
24. Monocusp valve
The monocusp is sutured to the
ventriculotomy opening with running 6-0
PTFE suture.
The suturing begins at the proposed
hinge point and extends onto the
epicardial surface of the ventricle with
bites that include at least one-half the
depth of the myocardium.
Care is taken to ensure that the superior
edge of the monocusp matches that of
the retained posterior leaflets.
25. Monocusp valve
The PTFE outflow tract patch forms a
roof over the monocusp.
This patch is sutured to the main
pulmonary artery and to the
ventriculotomy edge and in effect
reinforces the suture line of the
monocusp itself to the ventriculotomy
opening.
This patch is also sutured in place using
running 6-0 PTFE suture.
The patch is constructed in an
elongated teardrop configuration.
26. Monocusp valve
The functional characteristics of the
monocusp are demonstrated as follows.
The illustration on the left shows the
monocusp in diastole. Blood from the
pulmonary artery has filled the monocusp
and presses it against the septum and
remaining posterior pulmonary valve
leaflet. This is the coaptation site of the
monocusp.
In the illustration to the right, the
monocusp is in the open position; this
would be during systole. The monocusp is
flush with the RVOT anterior RV wall and
PTFE outflow tract patch.
The function of the monocusp can be
evaluated intraoperatively with
transesophageal echocardiography.
27. Monocusp valve
If the PTFE monocusp patch is too small or too large, it may not work properly and
would require reinstitution of cardiopulmonary bypass and revision of the patch.
However, multiple suture lines in the RVOT will result in injury to the muscle in this
area and make it difficult to obtain hemostasis.
This also might place the patient at risk for development of a pseudoaneurysm
through the suture line if there is sufficient damage to the edge of the muscle in
this area.
This technique is probably not suitable for patients who rely upon a competent
pulmonary valve, i.e., patients with tetralogy of Fallot and absent pulmonary valve,
or patients with significant peripheral pulmonary stenosis either congenital or
secondary to previous aorto-pulmonary shunts.
Patients with significant pulmonary hypertension might also be better served with
the use of a valved conduit.
28. Sung technique
In 2003, Si Chan Sung et al, from Dong-A university hospital, Pusan, South Korea,
published an operative technique of pulmonic valve annular enlargement with
concomitant valve repair using two pericardial patches to reduce pulmonary
regurgitation after complete repair of tetralogy of Fallot, in Annals of Thoracic
Surgery.
Their original paper was based on experience in just 18 patients, but was accepted
and appreciated worldwide
It was based mainly on the idea of making use of the native pulmonary valve tissue
in ToF patients undergoing trans annular patch across RVOT, unlike monocusp
valve, where it becomes non-functional or obstructive.
29. Sung technique
The main pulmonary artery (MPA) is opened longitudinally, and the valve is
inspected after induction of cardioplegia.
The most frequent finding is a bicuspid valve with varying degree of commissural
fusion and tethering to the MPA wall.
The first step of this technique is a precise division of the commissural fusion if
there is any.
If there are significant tetherings of valve cusps to the MPA wall, only the posterior
cusp is released from the tethering by scalpel to improve cusp excursion.
The tethering of the anterior cusp to the MPA is left untouched to preserve hinge
function of the newly created large anterior cusp
30. Sung technique
At this time, we have to decide whether
to enlarge the PV annulus or not.
If the annulus is not large enough in
size to be preserved, a small separate
vertical incision is made at the right
ventricular outflow tract (RVOT) free
wall.
The two incisions at the MPA and
RVOT are extended toward each other,
and they meet at the nadir of the
anterior PV cusp.
Then the anterior PV cusp is evenly
divided.
31. Sung technique
The next step is extensive infundibulectomy through the small ventriculotomy
incision and tricuspid valve.
The ventricular septal defect is closed through the tricuspid valve in all cases
except in doubly committed juxtaarterial defect.
Pulmonary valve reconstruction is then carried out in the arrested heart.
The extent of annular enlargement is decided by probing the PV with a Hegar
dilator.
The glutaraldehyde-treated autologous pericardium is adequately designed in the
rectangular shape.
The width of the patch is tailored according to the fraction of the Hegar dilator
circumference exposed at the annulus during RVOT calibration.
32. Sung technique
The patch is placed between the
divided valve cusps with continuous
over-and-over suture technique using a
6-0 monofilament suture.
Then the RVOT incision is
subsequently covered with the same
patch
It is important for the patch to be
placed at the endocardial side of the
incised myocardium at the upper half of
the RVOT incision.
This maneuver might be useful to
maintain good valve function because
the valve structure is a continuation of
the endocardium.
33. Sung technique
When the anterior cusp is very small or dysplastic, or the bicuspid PV has anterior
and posterior commissures, the PV division is performed near either commissure
to preserve the remaining valve tissue as much as possible, and one of two sides
of the pericardial patch is anchored to the incised MPA wall instead of valve tissue
at the same level of the commissure.
After completion of PV reconstruction and covering of the RVOT incision, the aortic
clamp is removed with procedures for removal of air first.
The incision at the MPA is then covered with a second ovoid glutaraldehyde-
treated bovine pericardial patch, which is connected to the middle or lower part of
the first RVOT patch.
34. Sung technique
The patch is placed to the epicardial
side of the incised RVOT wall.
As a result, a large anterior
pulmonary cusp with a large sinus is
created
35.
36. Sung technique
Sung had excellent results with his technique
No patient had significant pleural effusion or
other postoperative complication.
Two-dimensional echocardiography at
discharge showed excellent valve motion with
absent or mild PR in all patients
The mean pressure gradient across the PV was
6.6 mm Hg.
Fifteen patients had the same degree of PR
during the mean follow-up period of 10.6
months
All patients had excellent valve motion without
thickening of the repaired PV and no significant
increase of the mean pressure gradient through
the valve at the last follow-up
37. Primary valve replacement
Studies of placement of a prosthetic mechanical/bioprosthetic/homograft during
corrective surgery for ToF with trans-annular patch placement show promising results
It is usually practised in older children with ToF (mean age= 14yrs), who did not
undergo corrective surgery before (common in Indian scenario)
With known early failure of porcine heterografts in children, a gradient developed
across a prosthetic valve is better handled by the right ventricle
In adult ToF with fibrotic and less compliant myocardium of right ventricle, when
undergoing outflow patch reconstruction, pulmonary valve replacement offers better
right ventricular hemodynamics
This is particularly useful in adult ToF where large number of aortopulmonary collaterals
pose immense pressure on the right ventricle in presence of gross PI
38. The placement of prosthetic valve in
the pulmonary position under a right
ventricular patch allows use of larger
valve size than is possible with
valved conduits
Larger valve size relieves any
gradients and eliminates Pulmonary
regurgitation
In developing countries, cost
effective single operation is better
accepted than redo surgeries
39. Indications of Pulmonary Valve
Replacement
Current recommendations for surgical pulmonary valve replacement include:
significant PR (pulmonary regurgitation fraction (PRF) ≥ 25%)
significant PS (RV/systemic pressure > 2/3)
RV enlargement (EDVI ≥ 160 ml/m2, ESVI ≥ 80 ml/m2)
RV contractility impairment (RVEF ≤ 47%)
decreased end-diastolic LV volume (LVEDVI ≤ 65 ml/m2)
presence of symptoms particularly when pharmacological treatment is necessary
Other indications:
Exercise cardiopulmonary function deterioration
QRS duration > 140 ms
increased NT pro-BNP level
restrictive RV physiology (late diastolic forward flow through the pulmonary valve)
40. Pulmonary valve replacement in operated
case of ToF with PI
A preoperative transesophageal
echocardiography (TOE) is performed during
the Valsalva maneuver to determine whether
the patient has an intra-cardiac shunt.
If a shunt is not present, the procedure can
be carried out on the beating heart.
The redo-sternotomy can be technically
challenging due to adhesions and the
proximity of both the dilated right ventricle
and dilated aorta to the sternum.
The cardiopulmonary bypass (CPB) circuit is
set up to allow femoro-femoral cannulation,
as well as standard chest cannulation
41. If the chest opening is uneventful, the ascending aorta and both the caval veins are
cannulated and CPB is started. The femoral lines of the CPB circuit are clamped.
If femoro-femoral CPB is initiated due to complications during the sternotomy the aorta
and the superior vena cava (SVC) are cannulated switching the CPB into the chest.
The left femoral artery is dissected, decannulated, and repaired to avoid complication
due to reduction in distal perfusion.
The inferior vena cava (IVC) drainage is supplied by the right femoral venous cannula
that is left in place for the rest of the operation.
If preoperative imaging identifies that the cardiac structure is fused to the sternum, the
heart is decompressed by initiating femoro-femoral bypass prior to sternotomy. This is
achieved with a cutdown technique.
To ensure adequate distal perfusion of the left leg, the femoral artery is cannulated via
a conduit
42. After the sternotomy the RVOT is dissected and the calcified transannular patch is
excised.
The appropriate size biological pulmonary valve is chosen according to the
dimensions of the annulus.
The valve is positioned with the two struts lying anteriorly
The angulation of the valve when lying in the main pulmonary artery is important,
because it needs to be pointed inferiorly towards the pulmonary arteries (PAs).
The valve will allow a good flow in this position, and this allows effective support of
the transannular patch that will cover the valve.
The valve struts will sustain the transannular patch without distortion, channeling
the flow directly into the PAs.
43. The valve is secured with two hemi-continuous prolene sutures. This ensures the
borders of the free edges of the RVOT are sutured at the level of the two anterior
struts of the valve.
The transannular patch is measured using a silk string. The width of the patch is
determined by the length of silk required to encircle the valve from the free edges
of the RVOT at level of the annulus.
The initial length of the patch needs to be long, as it will be customized precisely
while being sewn.
The bovine pericardial patch is sutured to the pulmonary artery, and the suture line
is carried at the level of the valve on both sides.
Careful attention must be taken to prevent transannular leak at this level.
The patch is folded and the ring of the valve is fixed to the transannular patch at
the level of the fold.
The patch is again folded back, trimmed to the dimensions of the RVOT, and
sutured to the myocardium.
44. In some cases where the RVOT is extremely dilated, the valve can be sited directly
into the ventricle.
The valve is secured using the same technique.
In this particular case, the transannular patch did not need to be folded.
In patients with free PR, implanting a competent valve associated with RVOT
remodeling significantly reduces RV size early after operation.
45. Percutaneous options
Percutaneous pulmonary valve implantation (PPVI) is a
relatively new method of treating patients with right
ventricular outflow tract (RVOT) dysfunction after surgical
repair of congenital heart disease.
Since its introduction in 2000 by Bonhoeffer, more than ten
thousand PPVI procedures have been performed
worldwide.
Two types of valves are being used: Melody Medtronic
available in diameters 16 mm and 18 mm and the family of
Edwards SAPIEN valves 23, 26 and 29.
The procedure has been shown to be feasible and safe
when performed in patients with full pulmonary conduit
dysfunction and in selected cases of patched RVOT.
The low complication rate and the reduced number of open-
chest re-interventions over a patient’s lifetime are among
the main advantages of the procedure
46. The Melody valve, first used by Bonhoeffer, received
the CE Mark & Health Canada Approval in 2006 and
US FDA Approval in 2010.
In 90% of patients all over the world the Melody valve
was used.
The valve consists of a bare-metal platinum-iridium
stent (CP stent, NuMED, Inc., Hopkinton, New York)
and a manually sewn valved segment of bovine
jugular vein.
The device is available in diameters 16 and 18 mm.
Before implantation the device is crimpled over a
balloon-in-balloon catheter and mounted on a 18, 20,
or 22 mm delivery system (Ensemble, Medtronic,
Minneapolis, USA).
After being introduced into the pulmonary artery the
stent is uncovered and internal (the valve can still be
repositioned at this step) and external balloons are
inflated, resulting in the valve deployment.
The main limitation of the Melody valve is its relatively
small size
47. In 2006 Edwards-Cribier valve, having been used in
the aortic position, was implanted in the RVOT and
gave a beginning to a new family of Edwards
transcatheter pulmonic valves.
The Edwards SAPIEN valves (Edwards Lifesciences,
Irvine, California) are trileaflet bovine pericardial tissue
valves hand-sutured in a balloon-expandable,
radiopaque, stainless steel stent, available in 2
diameters: 23 and 26 mm.
The next generation Edwards SAPIEN XT valve has a
cobalt chromium frame, available also in diameter 29
mm, and is the first transcatheter heart valve
approved for pre-stented transannular patches.
SAPIEN3, equipped with an outer pericardial skirt, is
designed to minimize perivalvular leak.
The valve, manually crimped with a specialized tool, is
implanted using the Retroflex-3 or Novaflex delivery
system (Edwards Lifesciences) consisting of a guiding
catheter and a single-balloon catheter
48. Percutaneous pulmonary valve implantation is performed under general
anesthesia through the femoral, jugular, or subclavian veins.
Cardiac catheterization with assessment of the right heart, pulmonary and aortic
pressures precedes each implantation.
Right ventricular outflow tract angiograms in at least two orthogonal projections
allow one to assess its dimensions.
To enable precise measurements and estimation of the minimal outflow diameter
and balloon waist position, low pressure, 30 mm diameter/4 cm balloon inflations
(PTS-X Sizing Balloon Catheter, NuMED Canada Inc.) are performed.
To rule out any potential compression of the coronary arteries by the implanted
stent, simultaneous selective left and right coronary angiography should be
performed during balloon inflation in each patient.
Valve implantation is preceded by routine presenting with a bare metal stent.
Procedural success reaches 94–98% .
Hospitalization time usually does not exceed 4–5 days. Immediately after the
discharge patients are fit to work or able to go back to school
49. Other options: Valved conduit
Trans Annular Patch
Advantages
It relieves the RV pressure immediately
Child usually will not require reoperation
for RV outflow tract stenosis.
Disadvantages
sudden hemodynamic change for the
RV from a pressure-loaded to a volume-
loaded ventricle causing temporary RV
dysfunction
chronic volume overload can lead to
ventricular dysfunction from chronic
pulmonary valve insufficiency
Requirement of late pulmonary valve
insertion
Valved conduit
Advantages
Reliable, fully competent pulmonary
valve
Particularly useful in patients who
have peripheral unrepaired
pulmonary stenosis.
Disadvantages
All conduits (or pulmonary valves) are
subject to progressive stenosis, either
from patient growth or calcification of
the valves, and conduit replacement
is eventually needed