Synthetic absorbable sutures were used for surgery in the cardiovascular low pressure system of growing beagle dogs. Right atrial incisions were closed with this material in 20 dogs. In another 20 dogs caval anastomoses were performed in continuous suture technique. Repeated angiographies and histological examination were performed after observation periods between 5 and 180 days. No clinical complications occurred. Postoperatively patent anastomoses grew with the surrounding tissue, while stenotic anastomoses attained normal luminal diameter after suture absorption. Synthetic absorbable suture materials are recommended for use in the cardiovascular low pressure system, especially in the correction of congenital anomalies.