Indications for the Brock operation in current treatment of tetralogy of Fallot.

It is now generally accepted that a certain proportion of children with severe tetralogy of Fallot are anatomically unsuitable for one-stage total correction of the anomaly. The choice of the best preliminary operation for these is still in some doubt, however. Following Brock's original hypothesis that relief of the outflow obstruction will encourage enlargement of the main pulmonary artery and annulus (and therefore favour subsequent successful total correction) we have preferred this procedure in all cases not suitable for immediate total correction. In a consecutive series of 36 cases the results have been found to be very acceptable and to compare favourably with those obtained with anastomotic procedures such as the Blalock or Waterston shunt. The operation has been accomplished with an 11% mortality, and in 72% of cases cyanosis has been abolished under conditions of normal exercise. Sixteen cases have subsequently come to total correction with a 25% mortality and a 75% `cure' rate. In the light of this experience we find that closed pulmonary valvotomy with or without infundibular resection has a definite and valuable place in the current treatment of Fallot's tetralogy. General and specific indications for its use are presented.