Chapter 13

 

PULMONARY ARTERY STENOSIS AND STENOSIS OF
PULMONARY ARTERY BRANCHES

    This entity gains real identity with the development of angiography which is by all means the only accurate way to diagnose this congenital vascular disease.

   
Anatomy:   Isolate or multiple stenosis in the main pulmonary artery and/or its branches. Reduction in more than 500/0 of the total vascular cross section will produce hemodynamical alterations. If the vascular cross section is not reduced more than 50%, the great adaptability of the pulmonary vasculature to volume changes will compensate the problem and the patient's pulmonary pressures will remain almost normal.

    From the anatomical viewpoint the pulmonary artery stenosis can be classified as:

  1. Central stenosis (main trunk)
  2. Peripheral stenosis (branches)
  3. Multiple stenosis (main trunk and branches)
    When peripheral stenosis is present, one or both lungs can be affected.

PHYSIOLOGY AND HEMODYNAMICS

    The hemodynamical behavior will depend on the degree of stenosis.

  1. Stenosis less than 50 % of the total pulmonary vascular cross section = no hemodynamics changes.
  2. Stenosis of more than 50 % of the total pulmonary vascular cross section = pulmonary hypertension. In many cases these patients can be confused with primary pulmonary hypertension. This type of malformation is in 60 % to 75 % of cases associated to other congenital heart diseases, such as:
    1. PDA
    2. VSD
    3. Pulmonary valve stenosis
    4. Tetralogy of Fallot
    5. Dextrocardia

CLINICAL FINDINGS

Less than 50 % stenosis:   No symptoms.
More than 50 % stenosis:   Dyspnea, SOB, easy fatigability secondary to pulmonary hypertension.

PHYSICAL EXAMINATION

    Systolic and diastrolic (continuous) murmur. The area of localization will vary depending upon the location of this stenosis.
    Radiation of a continous murmur toward right axila should suggest the possibility of this malformation.    If pulmonary hypertension is present with right ventricular systolic overload, the proper physical findings of such entity will be present.

EKG

    Has no specific changes.
    Signs of pulmonary hypertension and secondary right ventricular systolic overload can be present.

ROENTGENOGRAM

    No specific features.
    The pulmonary arch will be more or less prominent than normal depending on the degree and location of the lesions.

CARDIAC CATHETERIZATION

    If the lesion is in the main pulmonary artery the gradient (systolic) will parallel the degree of stenosis.
    If the lesion is in the periphery, only accidental entering of the catheter of such vessel will indicate the problem.

ANGIOGRAPHY

    Is the only method to study properly this disease. High speed and high quality films are necessary for accurate diagnosis.