Internal configuration of saphenous-coronary anastomoses as studied by the cast-injection technique

A study of the internal configuration of saphenous vein--to--coronary artery anastomoses was undertaken to examine the effect of technical factors. One hundred fifty anastomoses were constructed in isolated swine hearts and epoxy-resin casts were made of the anastomoses by pressure-injection. The effects of interrupted sutures, continuous suture, vein tailoring, vein-to-artery size ratio, and end-to-side and side-to-side anastomoses were evaluated. We made several observations: (1) The external appearance of an anastomosis is not a reliable indicator of internal configuration. (2) Interrupted suturing consistently produces an internal configuration with minimal deformity. (3) Unless special precautions are taken with continuous suturing, severe deformities may occur. Very fine suture spacing and knotting distal corner sutures are recommended. (4) Proper vein-to-artery size ratio and "cobra-head" vein tailoring are desirable. (5) Side-to-side anastomoses are similarly significantly affected by suture techniques, vein graft size, venotomy size, and orientation. The study of the internal configuration of saphenous-coronary anastomoses is a simple and readily available method which should be useful to all coronary surgeons in assessing and perfecting their techniques.