William Glenn lecture. The cavopulmonary shunt. Evolution of a concept.

: A bold and imaginative development, the cavopulmonary anastomosis, appeared to originate in several centers almost simultaneously. After extensive research on right heart bypass, Glenn was the first in North America to perform a successful experimental cavopulmonary shunt, and it became known by his name. In properly selected patients, palliation success was excellent, and mortality rates were low. From 1961 through 1988, we used a cavopulmonary anastomosis for palliation in 139 infants and children. There were eight hospital deaths, and most occurred early in the series. Palliation generally lasted 6-8 years-until the child outgrew the blood supply to the contralateral lung. Palliation could be restored by increased flow to that lung with another shunt. Six otherwise inoperable patients received benefit from the addition of an axillary arteriovenous fistula. Late pulmonary arteriovenous fistulas were identified in 11% of our patients by angiography, but with more sensitive testing, the incidence rate may be as high as 21%. The occurrence of pulmonary arteriovenous fistulas caused general concern and less frequent use of the shunt. Recent application of an end-to-side anastomosis, creating a bidirectional shunt, has restored interest. A major legacy of the cavopulmonary anastomosis was demonstration of the feasibility of partial right heart bypass, which paved the way for the Fontan operation, and it is frequently constructed as part of that operation. Currently, the Glenn shunt is most often used as a temporary or permanent alternative to a Fontan repair if there appears to be significant risk. The risk factors usually encountered include small pulmonary arteries, young age, poor ventricular function, atrioventricular valve incompetence, and myocardial hypertrophy-sometimes alone but often in combination.(ABSTRACT TRUNCATED AT 250 WORDS)