Profound hypothermia with circulatory arrest: nine years' clinical experience.

A total of 550 intracardiac operations were performed with the aid of profound hypothermia and circulatory arrest between March, 1971, and December, 1979. Both cooling and rewarming were effected by means of an extracorporeal heat exchanger. Overall mortality was 20%, falling to 10% in 1979. Highest risks were associated with operations in the neonatal period and for unusually complex defects. The technique has proved safe for straight forward corrections in young age groups and is especially valuable for selected complex lesions in older children and those requiring reoperation. Although circulatory arrest has greatly extended the range of corrective heart operation in infancy, we believe there is still a significant place for palliative procedures in appropriate circumstances. Neurologic complications attributed to the technique have been uncommon, and only 4.5% of the survivors have any recognizable residual neurologic lesion, whether coincidental or resulting from circulatory arrest. The technique is simple, reliable, and generally safe.