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Pulmonary Stenosis

Pulmonary stenosis occurs in 10-12% of cases of congenital heart disease in adults. The obstruction is vascular in 90% of patients, but may occur above or below the valve itself. There may be associated other congenital heart defects. Although the three valve cusps (see figure 25) in stenosis are usually thin and pliant, their commissures are fused (see figure 25), leading to a dome-shaped valve with a small central opening during ventricular contraction (systole). The other 10% of cases have thickened, immobile and myxomatous. The normal valve area is 2.0 cm2 per square meter of body surface area, with no pressure gradient across the valve during systole. When the valve becomes stenotic, the right ventricle systolic pressure increases, creating a gradient across the valve. Pulmonary stenosis is mild, if the valve area is larger than 1.0 cm2 per square meter and the trans-valvular gradient is 50-80 mmHg, or the peak RV systolic pressure is less than 75 mmHg. The stenosis is moderate if valve area is 0.5-1.0 cm2 per square meter, trans-valvular gradient is 50-80 mmHg, or right ventricle systolic pressure is 75-100 mmHg. It is severe when the valve area is less than 0.5 cm2, and the gradient is more than 80 mmHg.

Diagnosis includes the following:

1) Physical examination. A thrill may be felt along the left sternal border. A murmur may be heard along the left sternal border.

The murmur comes from a narrowing of a segment of the pulmonary artery above the pulmonary valve or the narrowing can be in one of the pulmonary artery branches (right or left). The murmur is a harsh noise peaking in the middle of the cycle of the heart contracting to push blood through the pulmonary artery. The blood going through a narrowed segment of the pulmonary artery creates this noise, best heard just to the left of middle line of the chest, up close to and under the left collar bone (clavicle) and can also be heard under the left arm and in the back!

2) EKG show right ventricular wall thickening (RVH).

3) Echocardiogram show right ventricular wall thickening (RVH) and paradoxically septal (IVS) motion during systole, and the site of obstruction. Doppler studies can assess the degree of stenosis.

The clinical course of pulmonary stenosis is favorable in most patients
with mild to moderate obstruction. In a national study, 86% of patients had no increase in their pressure gradients over a 4- to 8-year interval. Those with a significant increase were less than 4 years of age and had at least moderte stenosis initially. Progression during the period of growth
seems to be the likely explanation for most of the increases, but a few patients developed subvalvular muscular hypertrophy, which increased the obstruction.

Even mild obstruction may progress significantly in some infants during
the first year of life. The prognosis of those with severe obstruction without intervention is poor, especially in infants with critical obstruction. With severe obstruction, right ventricular damage and dysfunction can ensure over the years, and heart failure or arrhythmias can cause premature death in adults.Tricuspid regurgitation also may result. Obstructon of the subvalvular type frequently increases with time. Brain abscess, infective endocarditis may occur.

In the above cited national study reevaluated 15 to 25 years later, the probability of 25-year survival was 95.6% compared with an expected age- and sex-matched control group survival of 96.6%.97% were asymptomatic. Studies suggested no pulmonary stenosis in 2 %, mild stenosis in 93%, moderate in 3%, and severe stenosis in only 1%

Treatment depends on the degree of stenosis .Frequent reexaminations
are indicated to detect any evidence of progression, with more frequent
evaluation for those under one year of age.

Balloon valvuloplasty has replaced surgery therapy as a first approach (see attached figures).

A thickened, immobile, dysplastc pulmonary valve is best treated by
complete excision. Sub valvular stenosis is relieved through a right
vehtriculotomy, a main pulmonary arteriotomy or a right atriotomy.

The blueness of the eyelids may represent cyanosis (desaturation of the
blood due to venous blood being mixed through a shunt like the atrial septal defect with oxygenated blood in the left atrium) and should be brought to the cardiologist's attention.


As an illustration of the use of stents in pulmonary artery branch stenosis, which had developed following surgical repair that was refractory to balloon dilatation, the following article by V.Mercieca,V.Grech and JV DeGiovanni in Images in Paediatric Cardiology(2004;20:1-10) is presented below.

Congenital pulmonary artery (PA) branch stenosis can occur in isolation, as part of a syndrome or in conjunction with other cardiac defects; quite often, PA branch stenosis occurs after surgical repair of congenital heart disease. Significant narrowing of the pulmonary artery origins can lead an overall reduction in pulmonary blood flow or to disproportionate distribution to the two lungs. In addition, an increase in right ventricular systolic pressure will result in right ventricular hypertrophy and possible failure. Moreover, coexistence of pulmonary regurgitation is made worse by PA branch stenosis. A right ventricular peak systolic pressure equal to or greater than 50% of the aortic systolic pressure or quantitative pulmonary perfusion scans showing ipsilateral lung perfusion <35% than predicted in unilateral stenoses are indications for intervention.

Percutaneous transluminal balloon angioplasty for PA branch stenosis is frequently of limited effectiveness in decreasing the pressure gradient, may have significant complications such as vessel rupture, dissection, aneurysm formation or even death and is often followed by recurrence. The latter has become less problematic with the advent of balloon expandable stents. The radial force of the stent holds the vessel open after deployment, counteracting the natural elastic recoil of the arterial wall. This elastic recoil of the vessel also helps to anchor the stent in place until epithelisation occurs. The collapsed stent is introduced over a deflated balloon catheter into the femoral vein through a long and wide Mullins sheath. Once the stent has been correctly positioned the balloon is inflated to deliver the stent over the stenosis in the vessel. The balloon is then deflated and withdrawn. Balloon expandable stents have added advantage that they can be further dilated when necessary as may be the case with growing children or in case of subsequent restenosis.

We present a patient with tetralogy of Fallot who developed bilateral branch pulmonary artery stenosis following surgical repair that was refractory to balloon dilatation. We describe simultaneous stenting of both PAs with a pleasing result.

Our patient, a 16 year old female had a repair of tetralogy of Fallot at the age of 14 months following a severe cyanotic spell. At operation the ventricular septal defect was closed with a Gortex patch and infundibular resection was carried out together with a trans-annular patch. She was left with a small residual ventricular septal defect which closed spontaneously, pulmonary regurgitation and mild residual infundibular stenosis. Postoperatively echocardiography demonstrated a dilated main pulmonary artery

and narrowing of the origin of the RPA with marked turbulence on colour flow mapping and peak Peak Doppler gradients were up to 60 mm Hg.

Fifteen years after surgery, balloon angioplasty was carried out for bilateral branch PA stenosis. The right had two levels of stenosis: main pulmonary artery (MPA) to distal right pulmonary artery (RPA) gradient 22 = mm Hg) and the left was tightly stenosed at its origin: MPA to left pulmonary artery (LPA) gradient = 30 mm Hg. The procedure did not produce any significant amelioration in gradients or angiographic appearance.

A further intervention was carried out at a later date with the intention to place stents to the origins of both PAs. Access to the LPA was from the right femoral vein and the RPA from the left femoral vein and a superstiff wire was used on each side.

Figure 1: (click here for video) RV angiogram — note RPA and LPA stenoses (arrows)


Figure 2: (click here for video) MPA angiogram further delineating LPA stenosis


Figure 3: Predilatation of LPA

As the LPA stenosis was complex and severe, it was decided to predilate with a high pressure balloon prior to stenting(figure 3).

Two separate Mullins sheaths sizes(11F on the left and 12F on the right side) were introduced in the PAs distal to the stenosis(figure 4).

Figure 5: Mullins sheaths in both branch PAs — stent mounted over balloon being delivered to the

Figure 6: Both stents being placed prior to deployment

Figure 7: Both Mullins sheaths withdrawn (tip of sheaths indicated by arrows) exposing both stents

Two 59 mm Genesis Cordis stents were used. The RPA stent was deployed on an 18mm Crystal balloon while a 16 mm MaxiLD balloon was used for the LPA stent. Precise positioning of the stents was evaluated by angiography through the Mullins sheath. Simultaneous inflation of the balloons by 2 operators working synchronously led to the deployment of the 2 stents at the same time; this is a crucial part of the technique in order to avoid displacement of one of the stents or occlusion of a PA branch. The anaesthetist provided a short period of apnoea during balloon inflation in order to minimise balloon movement or displacement.








Figure 8: (click here for video) Simultaneous inflation of both stents

The proximal and distal ends of the stents were flared open by inflating the balloon distally and proximally.


Figure 9: Proximal and distal ends of both stents being flared open. A. Distal end of RPA stent B.
Proximal end of RPA stent C. Proximal ends of both stents D. Distal end of LPA stent

Figure 10: LPA stent being reinflated

Figure 11: Final result



Figure 12: (click here for video) Final angiographic result

The gradients across the PAs on this occasion fell from 42 to 10 mm Hg on the right and from 50 to 8 mm Hg on the left. RV pressure fell from 70/- to 32/- following the procedure. There were no complications.

Figure 13: Echocardiographic parasternal short axis view showing A. RPA stent B. LPA stent.
Note stent mesh structure clearly visualised on 2D echocardiography

Figure 14: Continuous wave Doppler of right ventricular outflow tract and LPA showing A. Peak gradient before (60 mmHg) and B. Peak gradient after (37 mmHg)


Bilateral PA origin stenosis may require stenting and this should be done simultaneously. Pre-dilatation may be indicated in some cases and stability of the stents prior to deployment is essential using superstiff wires, apnoea and, if the degree of pulmonary regurgitation is severe, consider a large dose of adenosine, esmolol infusion or fast pacing.


1. Chandar JS, Wolfe SB, Rao PS. Role of stents in the management of congenital heart defects. J Invasive Cardiol 1996;8:314—325
2. Shaffer KM, Mullins CE, Grifka RG. Intravascular Stents in congenital heart disease: short and
long-term results from a large single-center experience. J Am Coll Cardiol 1998;31:661-667
3. Ing FF Grifka RG Nihill MR Mullins CE. Repeat dilation of intravascular stents in congenital
heart defects. Circulation 1995;92:893-897
4. Rao PS. Stents in the management of congenital heart disease in pediatric and adult patients.Indian Heart J. 2001;53:714-730

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