Pulmonary Stenosis
Seoul National University Hospital
Department of Thoracic & Cardiovascular Surgery
Pulmonary Stenosis and Intact
Ventricular Septum
1. Definition
A form of right ventricular outflow tract obstruction in which
stenosis is usually valvar or infundibular, or both ( rarely,
supravalvar )
* Simple, pure, isolated pulmonary valvar stenosis(70%)
* Pulmonary stenosis with normal aortic root
2. History
Doyen
Sellors
:
:
Brock
Swan
Kan
:
:
:
1st attempt of surgical relief in 1913
Closed transventricular instrumental valvotomy
repair in 1947
Closed valvotomy in 1948
Open correction during circulatory arrest in 1952
Percutaneous balloon valvuloplasty in 1982
Pulmonary Stenosis and Intact
Ventricular Septum
Pathophysiology
• Usually involves a stenotic valve that
obstructs right ventricular empting and
pulmonary blood flow, producing right
ventricular hypertrophy and cyanosis.
• Subvalvar and supravalvar stenosis are
other forms of this defect.
Pulmonary Stenosis and Intact
Ventricular Septum
 Patterns of pulmonary stenosis
1. Critical valvar pulmonary stenosis
in neonates
2. Pulmonary stenosis in infants,
children, & adults
Critical PS in Neonates
Morphology
1. Pulmonary valve
Uniform fibrous cone
Pulmonary valve dysplasia
2. Pulmonary arteries
Hypoplastic in 50%
3. Right ventricle
Mild to moderately reduced
Rarely severely reduced
Concentric ventricular
hypertrophy
Diffuse fibrosis
4. Tricuspid valve
Normal dimension in 50%
Severe hypoplasia in 10%
5. RV-Coronary A. fistulae
2% have fistulae
10% have sinusoids
6. Right atrium
Usually large, at least PFO
7. Coexisting cardiac diseases
Uncommon
Ebstein anomaly in 1%
Clinical Features & Diagnosis
Critical PS in Neonates
1. Critically ill, irritable, tachypneic, hypoxic
2. Tachycardia & heart failure, tricuspid insufficiency
may be present
3. Chest X-Ray, EKG show less evidence
4. Echocardiography, cardiac catheterization,
cineangiography provide precise information.
5. Tricuspid valve is competent in 10% & the other
90% show incompetence.
Critical PS in Neonate
Natural History
1. Presentation is nearly always within 1st 2 weeks of life.
2. All neonates in whom severe hypoxia develops die
without treatment, although some may live for a few
months.
Critical PS in Neonate
Operation for Critical PS
1. Percutaneous balloon valvotomy
2. Open pulmonary valvotomy using CPB
3. Transannular patch
4. Systemic-pulmonary artery shunt
3.5 - 4.0mm PTFE graft in case of PaO2
less than 30mmHg after CPB
Critical PS in Neonate
Special features of postoperative care
1. PGE1 intravenously preoperatively and early
postoperatively to maintain ductal patency
2. Infants should be restudied at 6-12 months
of age if systemic-pulmonary artery shunt has been
performed .
3. In about 10% of patients, follow-up evaluation
indicates important residual right ventricular
hypertension.
Critical PS in Neonate
Surgical Results
1. Survival
Early death ; less than 10%
Time-related survival
2. Modes of death
Hypoxia
Acute cardiac failure
3. Incremental risk factors
for premature death
RV enlargement
(cardiomyopathy)
Reduction of cavity size
without shunt
4. Reintervention
5. Residual RVOTO
6. Morphologic & functional
changes after valvotomy
RV cavity is normal or mildly
reduced in 90%.
More than 80% of patients ;
no tricuspid incompetence
PS - membranous
PS
PS with Post-stenotic
Dilatation
PS
Critical PS in Neonate
Indications for operation
1. Interventional treatment is indicated for all neonates.
2. Severe hypoplasia of the pulmonary annulus ( z < -4)
& severe reduction of RV cavity size; a transannular
patch & concomitant systemic-pulmonary artery shunt
are indicated in 10-20% of patients as initial procedure.
3. In patients who fail to develop adequate oxygen level
(more than 85% ) & RA pressure (less than 12-15mmHg)
at rest with atrial septum and shunt temporally closed,
Fontan operation is ultimately indicated.
PS in Infants, Children, Adults
Morphology
1. Pulmonary valve
Better developed than in neonates
Commissural fusion ; deformed,
thickened, myxomatous,
Secondary infundibular stenosis in older
patients
2. Pulmonary artery
Poststenotic dilatation in 70%
3. Right ventricle
Uncommon hypoplasia
Thickening of RV wall
10-20% have only infundibular stenosis
4. Tricuspid valve
Usually morphologically normal
5. Right atrium
Wall is hypertrophied
Patent foramem ovale in most
6. Left ventricle
Idiopathic hypertrophic subaortic
stenosis (Noonan syndrome)
Altered left ventricular geometry
affect ventricular function (revert
to normal after correction)
7. Associated anomalies
Noonan’s syndrome
Intrauterine rubella
Neurofibromatosis
Clinical Features & Diagnosis
 PS in Infants, Children, Adults
1. Symptoms
Symptomatic, but less severe than neonates
30-40% are asymptomatic.
Effort dyspnea & cyanosis may appear.
2. Signs
Systolic murmur with a thrill
Pulmonary component of second sound is decreased.
3. Electrocardiography
RAE, RAD, RVH
T- waves in right precordial lead
4. Echocardiography, catheterization & cineangiography
Pulmonary Stenosis with IVS
Natural History
1. Incidence
8~10% of CHD
Slightly predominance of females
2. Patients presenting in infancy
Wide variation of obstruction (mild stenosis in 40%,
moderate 47%. Severe 14%)
3. Patients presenting after infancy
Pressure gradient less than 25mmHg rarely progress.
4. Effect of right ventricular hypoplasia
14% of PS have varying degree of hypoplasia &
left untreated, affect unfavorably
Techniques of Operation
 PS in Infants, Children, Adults
1. Comment
Percutaneous balloon valvotomy is treatment of
choice for valvar pulmonary stenosis, if not possible,
open surgical valvotomy is indicated.
2. Open operation during CPB
Pulmonary valvotomy
Infundibular resection
Transanular patch
Techniques of Operation
Valvar PS ; Operative View
( Dysplastic leaflets with commissural fusion )
Special Features & Postoperative Care
 PS in Infants, Children, Adults
1. Withdrawl pressure tracing 24 hrs after operation
2. Known tendency for infundibular hypertrophy
to regress with time
3. When the RV is severely hypoplastic, symptoms and
signs are substantially altered, and when they appear
they tend to progress more rapidly.
4. Pulmonary stenosis with RV hypoplasia is associated
with less than the expected degree of RV hypertrophy.
5. Balloon valvotomy may not be as effective, & surgical
approach may be required in RV hypoplasia group.
Indications for Operation of PS
 PS in Infants, Children, Adults
1. When patients first show signs & symptoms, at one or
more months of age, pulmonary valvotomy is advisable.
2. Intervention is advised in asymptomqatic infants with
severe stenosis.
3. In those with moderate stenosis, intervention is debatable,
when stenosis is mild, not recommended.
4. In older patients, management differs only in the group
with moderate stenosis.
5. The presence and degrees of RV hypoplasia are taken
into account when deciding upon intervention.
Surgical Results of PS with IVS
PS in Infants, Children, Adults
1. Survival
Early deaths ; near zero
RV hypoplasia
Advanced chronic CHF
Time-related survival
2. Complete relief of PS
3. Reoperations
4. Cyanosis
When PFO or residual ASD
with impaired compliance,
& hypoplastic RV
5. Pulmonary incompetence
6. Morphologic changes
RV enlarges and becomes
normal size in most
Tricuspid incompetence is
usually absent late postop.
7. Functional Capacity
Excellent late result
Inferior in hypoplasic ventricle
Persistent, recurrent RV failure