Conduit Repair for Complex Congenital Heart Disease with Pulmonary Atresia or Right Ventricular Outflow Tract Obstruction*,**

Abstract

From 1972 to 1981, 40 valved extracardiac conduits have been implanted to bridge the right ventricular outflow tract (RVOT) in 37 patients for different complex congenital cardiac anomalies. The patients ranged in age from 2 to 23 years (mean 8.5 years). Two Dacron prostheses with incorporated Lillehei-Kaster valves, 1 valveless Dacron conduit, 27 Hancock conduits, and 9 lonescu-Shiley conduits were chosen according to availability and the progress in conduit technology. Thirty-three patients had had up to 4 previous palliative procedure before conduit repair. Although the complication rate appears considerable, the mortality rate seemed to be unaffected by the high percentage of prior surgery. Exchange of the conduit became necessary in 2 children, because of conduit stenosis with calcification of the Hancock valve 5 and 7 years respectively after implantation, and in another patient an outgrown Lillehei-Kaster valve Dacron conduit had to be replaced 9 years after repair. Five children died in the early postoperative course: one in pulmonary failure and kinking of the conduit; one with right heart failure and pulmonary hypertension stage IV; 2 in myocardial failure, and one due to severe bleeding from myocardial failure, and one due to severe bleeding from the prosthesis. Three patients died in the late postoperative course 11 weeks, 4 years and 4 years respectively after conduit repair. Conduit surgery offers new possibilities for repair of complex cyanotic cardiac malformations. At present, however, none of the commercially available conduits is an ideal substitute. Our limited experience with the hemodynamic results of lonescu Shiley conduits is promising although longer observation periods are needed for a definitive judgement. At present, the largest possible conduit should be used whenever possible; problems of compression or kinking can be avoided with proper positioning of the conduit.

Reconstruction of the right ventricular outflow tract with a bovine jugular vein graft fixed with a naturally occurring crosslinking agent (genipin) in a canine model

“…Specific problems encountered clinically include suboptimal hemodynamic performance and conduit kinking or compression. [5][6][7] In addition, fibrous peeling from the Dacron graft, which eventually results in valve dysfunction, has been reported previously. 5,7 To address these deficiencies, we undertook the development of a new biologic valved conduit: a bovine jugular vein graft with a retained native valve crosslinked with a naturally occurring crosslinking agent, genipin.…”

“…T here is a great medical need for the use of external valved conduits in the repair of many congenital cardiac anomalies to reconstruct the right ventricular outflow tract (RVOT). [1][2][3][4][5][6][7][8][9] Currently available valved conduits can be divided into 2 primary categories: allograft and xenograft. For the reconstruction of the RVOT, Homann and associates 9 reported that allografts show significantly better longterm durability than xenografts, regardless of the age at implantation and the diameter of the valved conduit.…”