The evolution of the treatment of isolated pulmonary valve stenosis.

In the course of studies covering 40 years, 1913 to 1953, leading to the development of cardiopulmonary bypass, many ingenious blind instrumental or digital intrusions were made into the heart chambers to treat lesions therein. Limits were defined for the arrest of circulation through part or all of the heart to permit a brief glimpse of the lesion and effect at least a partial correction. The often remarkably good results of operations performed under less than ideal operating conditions for lesions such as isolated pulmonary stenosis encouraged the interventional cardiologist and radiologist, working together, to adapt the cardiac catheter, used previously for exploration of the vascular system and diagnosing intravascular lesions, to therapeutic purposes. They positioned a catheter with uninflated balloon attached in the pulmonary artery, then either by inflating the balloon beyond the constricted orifice and pulling it through or by rapidly and precisely inflating the balloon lying across the orifice were able to disrupt the stricture and relieve the stenosis. Results matched those of early non-visual operations. Recently the cardiologist has expanded the approach to relieve other constricted orifices in the heart and great vessels and to close abnormal openings. In isolated pulmonary stenosis, the nearly complete relief of obstruction and the tolerance of the circulation to blunt disruption of valvular stenosis bodies well for the long-term success of balloon valvuloplasty in this congenital malformation of the heart.